NUREG-1640, Vol. 1

Radiological Assessments for

Clearance of Materials from

Nuclear Facilities

Main Report

U.S. Nuclear Regulatory Commission

Office of Nuclear Regulatory Research

Washington, DC 20555-0001
 

 NUREG-1640, Vol. 1

 

Radiological Assessments for

Clearance of Materials from

Nuclear Facilities

Main Report

Manuscript Completed: June 2003

Date Published: June 2003

Prepared by

R. Anigstein*, H.J. Chmelynski*, D.A. Loomis*,

S.F. Marschke**, J.J. Mauro*, R.H. Olsher*,

W.C. Thurber*, R.A. Meck

*SC&A, Inc.

6858 Old Dominion Drive

Suite 301

McLean, VA 22101

**Gemini Consulting Company

19 River Run Way

Oak Ridge, TN 37830

R.A. Meck, NRC Project Manager

Prepared for

Division of Systems Analysis and Regulatory Effectiveness

Office of Nuclear Regulatory Research

U.S. Nuclear Regulatory Commission

Washington, DC 20555-0001

NRC Job Code Number Y6047
Abstract

iii NUREG-1640

ABSTRACT

This report provides a complete description of calculations and their results estimating potential

annual doses, normalized to a unit concentration, to an individual following the clearance of

specific materials. These materials are scrap iron and steel, copper, aluminum, and concrete

rubble from licensed nuclear facilities. Clearance means the removal of radiological controls by

the licensing authority. The estimated potential doses are calculated probabilistically to account

for a large number of possible variations in each of the 86 scenarios. These scenarios encompass

the full range of realistic situations likely to yield the greatest normalized doses. Each scenario

was analyzed with the 115 radionuclides considered most likely to be associated with materials

from licensed nuclear facilities. The design basis of the analyses is to realistically model current

processes, to identify critical groups on a nuclide-by-nuclide basis, and to enable the conversion

of a dose criterion to a concentration. 

Material for recycle or disposal was evaluated using material flow models and dose assessment

models. Both models are based on probabilistic methods. This resulted in distributions of

nuclide-by-nuclide normalized doses from one year of exposure per mass- or surface-based

concentrations. The means and the 5th, 50th, 90th, and 95th percentiles are reported. These

percentiles can be used to generically evaluate the likelihood that the derived mean concentration

would correspond to a particular dose criterion. Additionally, they can be used to quantify the

confidence that a safety goal is not exceeded.
Contents

v NUREG-1640

CONTENTS

Page

Abstract . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . iii

Executive Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xv

Foreword . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xix

Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xxiii

Abbreviations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xxv

1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-1

1.1 Purpose and Scope . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-1

1.2 Exposure Scenarios . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-2

1.3 Parameter Values . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-3

1.3.1 Probabilistic Analyses . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-3

1.4 Critical Groups . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-4

1.5 Radionuclide Selection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-5

1.6 Exposure Pathways . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-7

1.6.1 External Exposure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-7

1.6.2 Internal Exposure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-8

References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-9

2 Summary of Results . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-1

2.1 Summary of Effective Dose Equivalents (EDEs) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-1

2.1.1 Mass-based EDEs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-1

2.1.2 Surficial EDEs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-2

2.2 Summary of Effective Doses . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-2

3 Recycling and Disposal of Steel Scrap . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-1

3.1 Introduction to Analysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-1

3.1.1 Approach to Scenario Development . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-2

3.1.2 Scenarios Characterizing the Recycling and Disposal of Cleared Steel Scrap . . 3-3

3.2 Flow of Steel Scrap . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-4

3.2.1 Sources of Cleared Steel Scrap . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-7

3.2.1.1 Secondary Recycling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-8

3.2.2 Recycling of Steel Scrap . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-9

3.2.3 Iron- and Steelmaking . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-10

3.2.3.1 Integrated Steel Mills . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-10

3.2.3.2 Non-Integrated Steel Mills . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-16

3.2.3.3 Iron and Steel Foundries . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-18

3.2.4 Output of Melting and Refining Processes . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-21

3.2.4.1 EAF Baghouse Dust . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-21

3.2.4.2 Slag . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-25

3.2.4.3 Metal Products . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-25

3.2.4.4 Miscellaneous By-Products . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-26

3.3 Mass Fractions and Partitioning Factors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-26
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Page

3.3.1 Mass Fractions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-26

3.3.1.1 Furnace Charge . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-27

3.3.1.2 Metal Product . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-28

3.3.1.3 Baghouse Dust and Sludge . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-28

3.3.1.4 Slag . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-29

3.3.2 Partitioning Factors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-29

3.3.2.1 Basic Assumptions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-29

3.3.2.2 General Methodology for Determining Partitioning of Impurities . . . . . . . . 3-30

3.4 Mixing of Cleared Scrap . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-32

3.4.1 Processing Scrap at Scrap Yard . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-32

3.4.2 Melting and Refining of Scrap . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-33

3.4.2.1 Annual-Average Mixing Factors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-33

3.4.2.2 Maximum Single-Heat Mixing Factors . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-34

3.4.2.3 Mixing of Waste in the Landfill . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-35

3.4.2.4 Mixing of EAF Dust During Processing and Disposal . . . . . . . . . . . . . . . . 3-35

3.5 Radionuclide Concentrations During Melting and Refining . . . . . . . . . . . . . . . . . . . 3-36

3.5.1 Annual-Average Concentrations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-36

3.5.2 Maximum Single-Heat Concentrations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-38

3.6 Exposure Pathways . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-38

3.6.1 External Exposure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-39

3.6.1.1 External Exposure to a Steady Stream of Material . . . . . . . . . . . . . . . . . . . 3-39

3.6.1.2 External Exposure to Single Product . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-40

3.6.2 Internal Exposure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-40

3.6.2.1 Inhalation Exposure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-40

3.6.2.2 Inadvertent (Secondary) Ingestion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-41

3.7 Dose Assessment of Recycling and Disposal of Steel Scrap . . . . . . . . . . . . . . . . . . . . 3-42

3.7.1 Handling and Processing Scenarios . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-42

3.7.1.1 Processing Steel Scrap at a Scrap Yard . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-44

3.7.1.2 Handling Slag at Steel Mill . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-45

3.7.1.3 Transferring EAF Dust at Steel Mill . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-46

3.7.1.4 EAF Baghouse Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-47

3.7.1.5 Handling Metal Product at Steel Mill or Foundry . . . . . . . . . . . . . . . . . . . . 3-47

3.7.1.6 Processing EAF Dust . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-47

3.7.1.7 Processing Steel Slag for Road Construction . . . . . . . . . . . . . . . . . . . . . . . 3-48

3.7.2 Emission of Airborne Effluents from Furnace . . . . . . . . . . . . . . . . . . . . . . . . . . 3-48

3.7.2.1 Atmospheric Dispersion Term . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-49

3.7.2.2 Ground-Surface Concentration Resulting from Atmospheric Releases . . . 3-51

3.7.2.3 Concentration in Edible Parts of Plants . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-52

3.7.2.4 Dose Calculation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-54

3.7.3 Transportation Scenarios . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-58

3.7.3.1 Truck Driver Hauling Cleared Steel Scrap . . . . . . . . . . . . . . . . . . . . . . . . . 3-58

3.7.3.2 Truck Driver Hauling Slag . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-59

3.7.3.3 Transportation of EAF Dust . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-61

3.7.3.4 Truck Driver Hauling Steel Products . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-63
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3.7.4 Product Use Scenarios—Annual-Average Mixing . . . . . . . . . . . . . . . . . . . . . . 3-64

3.7.4.1 Steel Ships . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-64

3.7.4.2 Road Built with Steel Slag . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-66

3.7.4.3 Living in Basement Built with Cement Made from Slag . . . . . . . . . . . . . . 3-70

3.7.5 Product Use Scenarios—Maximum Single-Heat Mixing Factor . . . . . . . . . . . 3-70

3.7.5.1 Exposure to Large Metal Mass . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-71

3.7.5.2 Exposure to Small Metal Mass . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-71

3.7.5.3 Small Steel Object on Body . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-71

3.7.5.4 Living in Home Built with Steel Studs . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-72

3.7.5.5 Driver of Automobile with Cast Iron Engine Block . . . . . . . . . . . . . . . . . . 3-72

3.7.5.6 Driver of Truck with Cast Iron Diesel Engine Block . . . . . . . . . . . . . . . . . 3-73

3.7.5.7 Sailor Berthing near Steel Hull Plate . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-73

3.7.6 Landfill Disposal Worker Scenarios . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-74

3.7.6.1 Handling Steel Scrap at an Industrial or MSW Landfill . . . . . . . . . . . . . . . 3-75

3.7.6.2 Handling BOF or Foundry Dust at an Industrial or an MSW Landfill . . . . 3-75

3.7.6.3 Handling Slag at an Industrial or an MSW Landfill . . . . . . . . . . . . . . . . . . 3-75

3.7.6.4 Handling EAF Dust at a Hazardous Waste Landfill . . . . . . . . . . . . . . . . . . 3-75

3.7.7 Consumption of Groundwater Infiltrated by Leachate . . . . . . . . . . . . . . . . . . . 3-76

3.7.7.1 Leachate from Landfills Used for the Disposal of Steel Scrap or 

BOF/Foundry Dust . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-76

3.7.7.2 Leachate from Slag Storage Pile . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-82

3.7.8 Scenario Timing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-90

3.7.8.1 Scrap Transportation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-91

3.7.8.2 Scrap Yard . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-91

3.7.8.3 Melting and Refining, and Processing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-91

3.7.8.4 Use of Iron and Steel Products . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-92

3.7.8.5 Slag Use and Disposal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-93

3.7.8.6 Dust Processing and Disposal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-93

3.8 Calculation of Surficial Normalized Doses . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-93

3.8.1 Mass-to-Surface Ratio . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-94

3.9 Dose Assessments of Recycling and Disposal of Steel Scrap . . . . . . . . . . . . . . . . . . . 3-95

3.9.1 Calculation of Effective Dose Equivalents (EDEs) . . . . . . . . . . . . . . . . . . . . . . 3-95

3.9.2 Calculation of Effective Doses . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-96

References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-111

4 Recycling and Disposal of Copper Scrap . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-1

4.1 Introduction to Analysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-1

4.2 Flow of Copper Scrap . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-1

4.2.1 Sources of Material . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-3

4.2.2 Recycling of Copper Scrap . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-4

4.2.3 Copper Refining . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-8

4.2.3.1 Fire Refining . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-8

4.2.3.2 Electrolytic Refining . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-10

4.2.3.3 Brass and Bronze Smelting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-11
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4.2.4 Product Use . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-12

4.2.4.1 Metal Products . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-12

4.2.4.2 Refinery By-products . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-13

4.3 Mass Fractions and Partitioning Factors for Refining Operations . . . . . . . . . . . . . . . 4-14

4.3.1 Mass Fractions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-14

4.3.1.1 Fire Refining . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-14

4.3.1.2 Electrolytic Refining . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-15

4.3.2 Partitioning Factors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-16

4.3.2.1 Fire Refining . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-16

4.3.2.2 Electrolytic Refining . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-16

4.4 Mixing of Cleared Scrap . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-16

4.4.1 Processing Copper Scrap at Scrap Yard . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-17

4.4.2 Secondary Fire Refining . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-17

4.5 Radionuclide Concentrations in Various Media . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-18

4.6 Dose Assessment of Copper Recycling and Disposal Scenarios . . . . . . . . . . . . . . . . 4-19

4.6.1 Inhalation and Inadvertent Ingestion of Copper Dusts . . . . . . . . . . . . . . . . . . . 4-19

4.6.2 Scrap Processing, and Handling of Fire-refined Copper Product . . . . . . . . . . . 4-19

4.6.3 Handling Copper Slag at Fire Refinery . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-21

4.6.4 Atmospheric Releases During Fire refining . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-21

4.6.5 Transportation Scenarios . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-22

4.6.6 Drinking Tapwater from Copper Pipes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-23

4.6.6.1 Exposure Pathways . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-23

4.6.6.2 Detailed Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-23

4.6.6.3 Concentration of Copper in Tapwater . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-24

4.6.7 Well Water Infiltrated by Leachate from Landfills Containing Copper Slag . . 4-25

4.6.8 Electrolytic Refineries . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-25

4.6.9 Brass Mills . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-26

4.6.10 Scenario Timing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-26

4.6.10.1 Scrap Transport and Handling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-26

4.6.10.2 Refining and Processing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-26

4.6.10.3 Transportation of Products of Fire Refining . . . . . . . . . . . . . . . . . . . . . . . 4-26

4.6.10.4 Use of Copper Products . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-27

4.7 Dose Assessments of Recycling and Disposal of Copper Scrap . . . . . . . . . . . . . . . . 4-27

4.7.1 Calculation of Effective Dose Equivalents (EDEs) . . . . . . . . . . . . . . . . . . . . . . 4-27

4.7.2 Calculation of Effective Doses . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-28

References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-42

5 Recycling and Disposal of Aluminum Scrap . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-1

5.1 Introduction to Analysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-1

5.2 Flow of Aluminum Scrap . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-2

5.2.1 Sources of Material . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-3

5.2.2 Recycling of Aluminum Scrap . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-4

5.2.3 Secondary Smelters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-5

5.2.4 Product Use . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-8
Contents

ix NUREG-1640

Page

5.3 Mass Fractions and Partitioning Factors for Smelter Operations . . . . . . . . . . . . . . . . . 5-9

5.3.1 Mass Fractions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-9

5.3.1.1 Adopted Values . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-11

5.3.2 Partitioning Factors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-12

5.4 Mixing of Cleared Scrap . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-13

5.4.1 Transport of Aluminum Scrap . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-13

5.4.2 Processing Aluminum Scrap at Scrap Yard . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-14

5.4.3 Secondary Smelter Operations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-14

5.4.3.1 Annual-Average Mixing Factors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-14

5.4.3.2 Single-Heat Mixing Factors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-14

5.5 Radionuclide Concentrations in Various Media . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-15

5.6 Aluminum Recycling and Disposal Scenarios . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-15

5.6.1 Inhalation of Aluminum Dusts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-16

5.6.2 Handling Dross at Secondary Smelter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-16

5.6.3 Use of Aluminum Cooking Ware . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-16

5.6.3.1 External Exposure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-16

5.6.3.2 Ingestion Exposure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-18

5.6.4 Scenario Timing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-18

5.6.4.1 Scrap Transport and Handling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-18

5.6.4.2 Refining and Processing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-19

5.6.4.3 Transportation of Smelter Products . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-19

5.6.4.4 Use of Aluminum Products . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-19

5.7 Dose Assessments of Recycling and Disposal of Aluminum Scrap . . . . . . . . . . . . . . 5-20

5.7.1 Calculation of Effective Dose Equivalents (EDEs) . . . . . . . . . . . . . . . . . . . . . . 5-20

5.7.2 Calculation of Effective Doses . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-21

References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-34

6 Recycling and Disposal of Concrete Rubble . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-1

6.1 Introduction to Analysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-1

6.2 Flow of Concrete Rubble . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-1

6.2.1 Sources of Material . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-2

6.2.1.1 Mass-to-Surface Ratio . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-3

6.2.2 Transportation and Processing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-4

6.2.3 Use of Recycled Concrete . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-5

6.2.4 Disposal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-6

6.3 Concrete Recycling and Disposal Scenarios . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-7

6.3.1 Inhalation of Dust . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-7

6.3.2 Processing Concrete Rubble at Satellite Facility . . . . . . . . . . . . . . . . . . . . . . . . . 6-9

6.3.3 Transport of Concrete Rubble . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-9

6.3.4 Landfill Disposal Workers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-9

6.3.5 Concrete Road Scenarios . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-10

6.3.6 Scenario Timing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-10

6.4 Dose Assessments of Recycling and Disposal of Concrete Rubble . . . . . . . . . . . . . . 6-10

6.4.1 Calculation of Effective Dose Equivalents (EDEs) . . . . . . . . . . . . . . . . . . . . . . 6-11
Contents

NUREG-1640 x

Page

6.4.2 Calculation of Effective Doses . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-12

References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-26

7 Quality Control Program . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-1

References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-2

8 Glossary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-1

References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-10
Contents

xi NUREG-1640

Figures

Page

1.1 Frequency distributions of normalized doses from a hypothetical source . . . . . . . . . . . . . 1-4

3.1 Flow of steel scrap . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-5

3.2 Examples of steelmaking processes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-11

3.3 Schematic diagram of airborne emissions scenario . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-49

3.4 Transport of leachate from landfill to well . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-79

3.5 Scenarios giving rise to EDE-critical groups for steel . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-96

3.6 Scenarios giving rise to effective dose-critical groups for steel . . . . . . . . . . . . . . . . . . . . 3-98

4.1 Flow of copper scrap . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-3

4.2 Operations in the primary and secondary production of copper . . . . . . . . . . . . . . . . . . . . . 4-7

4.3 Scenarios giving rise to EDE-critical groups for copper . . . . . . . . . . . . . . . . . . . . . . . . . 4-28

4.4 Scenarios giving rise to effective-dose critical groups for copper . . . . . . . . . . . . . . . . . . 4-29

5.1 Flow of aluminum scrap . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-2

5.2 Processing and melting of aluminum scrap at typical secondary smelter . . . . . . . . . . . . . 5-7

5.3 Scenarios giving rise to EDE-critical groups for aluminum . . . . . . . . . . . . . . . . . . . . . . . 5-20

5.4 Scenarios giving rise to effective dose-critical groups for aluminum . . . . . . . . . . . . . . . 5-21

6.1 Flow of concrete rubble . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-2

6.2 Scenarios giving rise to EDE-critical groups for concrete . . . . . . . . . . . . . . . . . . . . . . . . 6-11

6.3 Scenarios giving rise to effective dose-critical groups for concrete . . . . . . . . . . . . . . . . . 6-13
Contents

NUREG-1640 xii

Tables

Page

1.1 Radionuclides of interest in the analysis of recycling and disposal of cleared materials . . 1-6

2.1 Normalized effective dose equivalents to critical groups for all materials . . . . . . . . . . . . 2-3

2.2 Normalized effective doses to critical groups for all materials . . . . . . . . . . . . . . . . . . . . . 2-6

3.1 Scenarios discussed in previous studies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-4

3.2 Integrated iron and steel mills . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-12

3.3 Analysis of top-blown BOF and Q-BOP fume . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-15

3.4 Particulate emissions for cupola furnaces with various emission control devices . . . . . . 3-20

3.5 Disposal of EAF dust . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-22

3.6 Buildup of heavy metals in soil from use of EAF dust as fertilizer . . . . . . . . . . . . . . . . . 3-24

3.7 Key data for development of mass flow parameters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-27

3.8 Partitioning in steelmaking . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-32

3.9 Partitioning in cast iron melting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-33

3.10 Scenario and exposure pathway matrix . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-43

3.11 Absolute Humidity in Continental United States . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-54

3.12 Weekly hours of Type 2 drivers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-60

3.13 Weekly hours of Type 1 drivers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-62

3.14 Hours spent in truck sleeper berth . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-63

3.15 Time spent traveling in a car (min/d) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-69

3.16 Landfill parameters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-83

3.17 Leaching parameter values . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-86

3.18 Diffusion coefficients for EAF slag monolithic samples . . . . . . . . . . . . . . . . . . . . . . . . 3-86

3.19 Normalized mass-based EDEs from selected nuclides (:Sv/y per Bq/g) . . . . . . . . . . . . 3-97

3.20 Normalized mass-based effective doses from selected nuclides (:Sv/y per Bq/g) . . . . 3-97

3.21 Normalized mass-based effective dose equivalents to critical groups for steel . . . . . . . 3-99

3.22 Normalized surficial effective dose equivalents to critical groups for steel . . . . . . . . . 3-102

3.23 Normalized mass-based effective doses to critical groups for steel . . . . . . . . . . . . . . . 3-105

3.24 Normalized surficial effective doses to critical groups for steel . . . . . . . . . . . . . . . . . 3-108

4.1 Copper recovered from copper-base scrap in 2000 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-5

4.2 Copper recovered from copper-base scrap by type of operation in 2000 . . . . . . . . . . . . . . 4-5

4.3 Unalloyed copper and total copper recovered from copper-base alloys in 2000 . . . . . . . . 4-6

4.4 Unalloyed copper products made from scrap in 2000 . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-6

4.5 Partitioning in fire refining of copper . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-17

4.6 Partitioning in electrorefining of copper . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-18

4.7 Scenario and exposure pathway matrix . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-20

4.8 Mass-based normalized effective dose from Mo-93 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-29

4.9 Normalized mass-based effective dose equivalents to critical groups for copper . . . . . . 4-30

4.10 Normalized surficial effective dose equivalents to critical groups for copper . . . . . . . . 4-33

4.11 Normalized mass-based effective doses to critical groups for copper . . . . . . . . . . . . . . 4-36

4.12 Normalized surficial effective doses to critical groups for copper . . . . . . . . . . . . . . . . . 4-39
Contents

xiii NUREG-1640

Tables (continued)

Page

5.1 Mass-to-surface ratios of commercial aluminum sheets . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-4

5.2 U.S. industrial consumption and recovery from purchased aluminum scrap in 2000 . . . . 5-6

5.3 Product net shipments by major market in 2001 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-9

5.4 Comparison of mass fractions in secondary aluminum smelting . . . . . . . . . . . . . . . . . . . 5-11

5.5 Partitioning of contaminants in aluminum smelting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-13

5.6 Scenario and exposure pathway matrix . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-17

5.7 Normalized mass-based effective dose equivalents to critical groups for aluminum . . . . 5-22

5.8 Normalized surficial effective dose equivalents to critical groups for aluminum . . . . . . 5-25

5.9 Normalized mass-based effective doses to critical groups for aluminum . . . . . . . . . . . . 5-28

5.10 Normalized surficial effective doses to critical groups for aluminum . . . . . . . . . . . . . . 5-31

6.1 Concrete mass-to-surface ratios for components of reference 1,000 MWe PWR . . . . . . . 6-3

6.2 Scenario and exposure pathway matrix . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-7

6.3 Normalized mass-based EDE from selected nuclides . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-12

6.4 Normalized mass-based effective doses from selected nuclides . . . . . . . . . . . . . . . . . . . 6-13

6.5 Normalized mass-based effective dose equivalents to critical groups for concrete . . . . . 6-14

6.6 Normalized surficial effective dose equivalents to critical groups for concrete . . . . . . . 6-17

6.7 Normalized mass-based effective doses to critical groups for concrete . . . . . . . . . . . . . . 6-20

6.8 Normalized surficial effective doses to critical groups for concrete . . . . . . . . . . . . . . . . 6-23
Contents

NUREG-1640 xiv

Appendices

Volume 2: Appendices A – E

A Inventory of Materials from NRC and Agreement State Licensees

B Parameter Values

C External Exposure Dose Coefficients

D Mixing of Cleared Materials

E Ingrowth of Radioactive Progeny

Volume 3: Appendices F – G

F Results of Assessments of Iron and Steel Scrap

G Results of Assessments of Copper Scrap

Volume 4: Appendices H – O

H Results of Assessments of Aluminum Scrap

I Results of Assessments of Concrete Rubble

J Partitioning Factors and Mass Fractions

K Normalized Radionuclide Concentrations

L Chemical Form and Particle Size

M Results of Single Heat Scenarios in Steel Analysis

N Scoping Analyses

O Quality Management Plan
Executive Summary

xv NUREG-1640

EXECUTIVE SUMMARY

This report provides a complete description of calculations and their results estimating potential

annual doses to an individual following the clearance of specific materials. These materials are

scrap iron and steel, copper, aluminum, and concrete rubble from licensed nuclear facilities. 

Clearance means the removal of radiological controls by the licensing authority—in this case,

the U.S. Nuclear Regulatory Commission. The estimated potential doses are calculated

probabilistically to account for a large number of possible variations in each of the 86 scenarios. 

These scenarios encompass the full range of realistic situations likely to yield the greatest

normalized doses. Each scenario was analyzed with the 115 radionuclides considered most

likely to be associated with materials from licensed nuclear facilities. 

The design objectives of this report include incorporating more realistic modeling of current

industrial practices in the United States, as well as current data on the living habits of the U.S.

population. This objective was implemented to minimize unnecessary conservatism, i.e.,

overestimation of potential doses. The results of these analyses can be used as part of the

technical basis to support regulatory considerations. Specifically, they can be used to identify

critical groups and to relate a dose-based requirement to a mass-based or surface-based

concentration of a radionuclide. However, this technical report, in itself, cannot be inferred to

represent any regulatory policy or any regulatory decision. 

This final report addresses and resolves public and NRC staff comments on the draft, as well as

the comments received from two independent reviews. One was a peer review conducted by the

Center for Nuclear Waste Analyses; the other was a review by the National Research Council,

part of the National Academies. The draft of this report was published in March 1999. This

final report is organized as a main report, volume 1, that summarizes the approaches, the

mathematical formulations and the main results. The appendices are published in succeeding

volumes and provide the detailed technical inputs to the calculations and the detailed results. A

description of the main report and the titles of the appendices follow. 

Chapter 1 describes the design objectives and the general approaches for the analyses. A brief

description of how the uncertainties for each analysis were generated is as follows. Each

individual calculation, whether it is the assessment of a radiation dose in a given scenario or the

concentration of a given radionuclide in a given medium, is deterministic—it employs a set of

fixed values of the relevant parameters and produces a fixed result. For parameters that are

uncertain or variable, Monte Carlo sampling methods are used to pick the particular set of values

in a given calculation, called a realization. In the present analysis, the estimation of each dose,

radionuclide concentration, or other intermediate parameter involved between 5,800 and 10,000

realizations. These 5,800 to 10,000 results themselves form a probability distribution. The mean

value and the 5th, 50th, 90th, and 95th percentile values of each such distribution are listed in

subsequent parts of the present report. These percentiles can be used to generically evaluate the

likelihood that the derived mean concentration would correspond to a particular dose criterion. 

Additionally, they can be used to quantify the confidence that a safety goal is not exceeded. 
Executive Summary

NUREG-1640 xvi

Two different dosimetric quantities were calculated in these analyses. One is the effective dose

equivalent (EDE). The EDE is based on recommendations presented in ICRP (International

Commission on Radiation Protection) Publication 26, published in 1977. NRC radiation

protection regulations are based on these recommendations. The second is the effective dose. 

The calculations of effective dose are based on the current recommendations, adopted by the

ICRP in 1990. These are presented in ICRP Publication 60, and incorporate the respiratory tract

model described in ICRP Publication 66 as well as new bio-kinetic models for specific

radionuclides presented in ICRP Publications 56, 67, and 69. The results are normalized to

initial unit activity concentrations at the point of clearance, that is, from the licensed facility. 

The results are expressed in terms of the EDE and effective dose from one year of exposure per

unit activity in a gram or on a square centimeter of cleared material, for each separate

radionuclide in each material. 

Chapter 2 is an overall summary of the results. It takes into account all scenarios, radionuclides,

and materials. The highest mass-based normalized doses from about 80% of the radionuclides

are from the clearance of concrete rubble, the critical group for about 40 of these nuclides

comprising workers using the rubble for road construction. For the remainder of the

radionuclides, the highest results were from the steel scenarios. The results, normalized to unit

surficial activities on scrap and concrete rubble, were highest for steel for most of the

radionuclides. Copper scenarios yielded the remainder of the high surficial results. 

Chapter 3 addresses the recycling and disposal of steel scrap. It also lays the mathematical

formulations of the assessments and serves as the template for the analyses of other materials.

The assessment addresses 37 scenarios that depict exposures resulting from the handling and

processing of cleared scrap and the products of melting and refining this scrap at steel mills and

foundries, emission of airborne effluents from these facilities, transportation of scrap and furnace

products, the use of these products, the landfill disposal of cleared scrap and furnace byproducts, and the infiltration of well water by leachate from landfills and storage piles containing

cleared scrap or furnace by-products. The analyses utilize data on ferrous metal recycling, as

currently practiced in the United States, and on contemporary U.S. work practices and living

habits. The mean doses to the groups of exposed individuals characterized by 30 of these

scenarios are ranked to determine the critical groups for each radionuclide. The analyses and

results of the remaining seven scenarios were placed in an appendix of this report, because they

were considered to be a special case and not representative of general industrial practices. The

critical group for the largest number of radionuclides, accounting for over one-third of the 115

radionuclides in the analyses, consists of workers processing scrap at a scrap yard. The critical

groups for the remaining radionuclides are distributed among eight other scenarios.

Chapter 4 addresses copper scrap recycling and disposal. The assessments address 20 scenarios

that depict exposures resulting from the handling and processing of cleared scrap and the

products of melting and refining this scrap at secondary copper producers, emission of airborne

effluents from these facilities, transportation of scrap and furnace products, the use of copper

products, the landfill disposal of cleared scrap and reverberatory furnace slag, and the infiltration

of well water by leachate from landfills containing cleared scrap or reverberatory furnace slag. 

The analyses utilize data on secondary copper production, as currently practiced in the United
Executive Summary

xvii NUREG-1640

States, and on contemporary U.S. work practices and living habits. The critical group for the

largest number of radionuclides, accounting for over three-fourths of the 115 radionuclides in the

analyses, consists of workers handling copper slag at a secondary fire refinery. The critical

group accounting for the second largest number of nuclides comprises workers processing

copper scrap at a scrap yard. Three other scenarios give rise to the critical groups for the

remaining nuclides, which constitute less than eight percent of the total. 

Chapter 5, on aluminum scrap recycling and disposal, is similar in approach. The assessments

address 21 scenarios that depict exposures resulting from the handling and processing of cleared

scrap and the products of melt-refining this scrap at secondary aluminum smelters, emission of

airborne effluents from these facilities, transportation of scrap and smelter products, the use of

aluminum products, the landfill disposal of cleared scrap and aluminum dross, and the

infiltration of well water by leachate from landfills containing cleared scrap or dross. The

analyses utilize current data on U.S. secondary aluminum smelters, and on contemporary U.S.

work practices and living habits. The critical group for the largest number of radionuclides,

accounting for most of the 115 radionuclides in the analysis, consists of workers processing

scrap at a scrap yard. Scenarios involving the use of aluminum products—the owner-operator of

a taxi with an aluminum engine block or a person using an aluminum cooking utensil—give rise

to most of the remaining critical groups. 

Chapter 6 is on the recycling and disposal of concrete rubble. The assessments address eight

scenarios that depict exposures resulting from the handling and processing of cleared concrete

rubble, transportation of the rubble, the use of recycled concrete in road construction, the landfill

disposal of concrete rubble, and the infiltration of well water by leachate from landfills

containing concrete rubble. The analyses utilize data on concrete recycling and disposal, as

currently practiced in the United States, and on contemporary U.S. work practices and living

habits. The critical group for almost one-half of the 115 radionuclides addressed by the present

analysis consists of workers processing concrete rubble for recycling or disposal. Workers

building a road with recycled concrete constitute the critical group for most of the remaining

nuclides. 

Chapter 7 is a description of the quality control program that was used throughout the

formulation of the analysis and the calculation and reporting of the results. The purpose this

program was to ensure that the radiological assessments of the recycling and disposal of cleared

materials are defensible, accurate, and verifiable. A Quality Management Plan (QMP) was

prepared and followed during the conduct of this analysis. The QMP includes specification of

procedures and conventions adopted to implement quality control for the present analysis. The

QMP also describes requirements for model development, mathematical analyses, and software

implementation, and also specifically addresses requirements for the preparation, review,

verification, documentation, and record keeping of technical information. The QMP therefore

provides a documented system for ensuring accuracy of results, as well as a basis for tracing

calculations. The QMP incorporated quality assurance guidelines provided by the NRC and

other recognized authorities. 

Chapter 8, the final chapter, is a glossary of technical terms.
Executive Summary

NUREG-1640 xviii

The following is a listing of the appendices contained in Volumes 2, 3 and 4: 

Volume 2: Appendices A – E

A Inventory of Materials from NRC and Agreement State Licensees

B Parameter Values

C External Exposure Dose Coefficients

D Mixing of Cleared Materials

E Ingrowth of Radioactive Progeny

Volume 3: Appendices F – G

F Results of Assessments of Iron and Steel Scrap

G Results of Assessments of Copper Scrap

Volume 4: Appendices H – O

H Results of Assessments of Aluminum Scrap

I Results of Assessments of Concrete Rubble

J Partitioning Factors and Mass Fractions

K Normalized Radionuclide Concentrations

L Chemical Form and Particle Size

M Results of Single Heat Scenarios in Steel Analysis

N Scoping Analyses

O Quality Management Plan
Foreword

xix NUREG-1640

FOREWORD

This report provides a complete description of calculations and their results. The results are

estimates of potential annual doses, normalized to a unit of radioactivity in a gram or on a square

centimeter of surface, to an individual following the clearance of three kinds of metal scrap and

of concrete rubble from licensed nuclear facilities. Clearance means the removal of radiological

controls by the licensing authority—in this case, the U.S. Nuclear Regulatory Commission. The

estimated potential doses are calculated probabilistically to account for a large number of

possible variations in each of the respective scenarios. The assessments specifically address

steel, copper and aluminum scrap, and concrete rubble. These materials represent a large

fraction of those that potentially could be cleared from licensed facilities. Additional

assessments of potential doses following the clearance of equipment for reuse, ordinary trash,

and soils are planned for a supplement to this report.

This final report addresses and resolves public and NRC staff comments on the draft, as well as

the comments received from two independent reviews. One was a peer review conducted by the

Center for Nuclear Waste Analyses; the other was a review by the National Research Council,

part of the National Academies. The draft of this report was published in March 1999. The

design objectives of the final report include incorporating more realistic modeling of current

industrial practices in the United States, as well as current data on the living habits of the U.S.

population. The results were calculated by design to avoid needlessly conservative assumptions

in the formulation of the models and the selection of the parameters used with the models. 

Consequently, as a significant part of the technical basis for the potential regulatory applications

listed below, this report relates directly to the NRC Performance Goals that speak to: protecting 

the environment, implementing more effective, efficient, and realistic activities and decisions,

increasing public confidence, and reducing unnecessary regulatory burden. 

A considerable amount of data was obtained from the secondary metals and concrete recycling

industries. The study also utilized the detailed information that had been compiled by the U.S.

Environmental Protection Agency (EPA) on the consumption of foods and water from various

sources, and on time devoted to various daily activities, by various segments of U.S. population. 

The results of the revised analyses provide much more realistic quantitative estimates of

potential doses and their corresponding uncertainties. Estimated potential doses were assessed

for one year of exposure and normalized to either a unit of radioactivity in a gram of cleared

material or on a square centimeter of the surface of such material. 

Two different dosimetric quantities were calculated in these analyses. One is the effective dose

equivalent (EDE). The EDE, based on recommendations presented in ICRP (International

Commission on Radiation Protection) Publication 26, is the basis of the EPA’s Federal Guidance

Reports Nos. 11 and 12, and is also the basis for the NRC’s current regulations for radiological

protection. The second is the effective dose. The calculations of effective dose are based on

more current recommendations presented in ICRP Publication 60, and incorporate the respiratory

tract model described in ICRP Publication 66 as well as new bio-kinetic models for specific

radionuclides presented in ICRP Publications 56, 67, and 69. These methodologies are the basis

of EPA’s Federal Guidance Report No. 13.
Foreword

NUREG-1640 xx

Regulatory Applications of this Report

For generic rulemaking, individuals in the scenario with the greatest mean normalized dose can

be identified as the critical group for that material on a radionuclide-by-radionuclide basis. 

Regulatory decisions that concern the dose to an individual typically are based on the average

dose in the critical group. Limiting the potential dose to critical group individuals ensures that

the average potential dose to any other group would be smaller. A total of 86 exposure scenarios

were judged to be realistic candidates for identification of the critical groups among the materials

analyzed. These scenarios were assessed for each of the 115 radionuclides considered most

likely to be associated with materials in licensed nuclear facilities. For each radionuclide, the

greatest mean normalized dose among all the materials analyzed can be used to generically limit

the concentration for that radionuclide among all the materials. Alternatively, concentrations

corresponding to a dose criterion could be used for metals collectively or specifically applied to

each type of metal, and concentrations derived from the analyses of critical groups for concrete

could be separately applied. 

Additionally, for rulemaking considerations, estimated potential doses to collections of

individuals in a large variety of scenarios may be used as a starting point for evaluation of the

collective dose in cost-benefit analyses. A cost-benefit analysis is required in the Generic

Environmental Impact Statement and the Regulatory Analysis to justify a regulatory change. 

Case-by-case regulatory decisions are required in response to requests from licensees. The large

variety of scenarios analyzed in this report may be realistically applied to certain situations in

licensing requests. In other cases, the models and scenarios may be adapted to specifically fit the

situation at hand. Such applications are facilitated by the explicit presentation of the exposure

scenarios, calculational models, modeling parameters, and mathematical formulations in this

report. The dose assessments in this report may also be used to reconstruct doses, when the

exposure situation is sufficiently similar to the ones analyzed. 

The effective dose calculations, based on the current ICRP recommendations and models,

facilitate comparisons with similar assessments for clearance by the International Atomic Energy

Agency (IAEA) and the European Commission. These comparisons may be valuable when

making comparisons of import and export practices for these commodities. 

Regulatory policies, decisions, guidance, and regulations are distinct from this technical report. 

This report is limited to technical information and cannot be used to infer any of the above

regulatory instruments.
Foreword

xxi NUREG-1640

Other uses for this report

Licensees may use the approaches, models, or results of this report to evaluate operational

situations or to prepare requests for action from the NRC or State regulators. Others who are

interested in the subject matter may use this report to better understand industry processes and

the modern methods of dose assessment used in radiation protection.

Farouk Eltawila, Director

Division of Systems Analysis and Regulatory Effectiveness

Office of Nuclear Regulatory Research
Acknowledgments

xxiii NUREG-1640

ACKNOWLEDGMENTS

The authors are pleased to acknowledge the support and patience of the NRC management

during the significant refinements required to respond to comments on the draft version of this

report. These comments were numerous and included two additional reviews—a peer review by

the Center for Nuclear Waste Regulatory Analyses (CNWRA) and a review by the National

Research Council, part of the National Academies. Management support included the ad hoc

Steering Group, and particular recognition is due to Carl Paperiello, Ashok Thadani, Farouk

Eltawila, and Cheryl Trottier. 

NRC staff colleagues contributed substantially with comments on both on approaches and

details. They include, in alphabetical order: 

Ralph Cady

Frank Cardile

Carl Feldman

Giorgio Gnugnoli

Anthony Huffert

Stephen Klementowicz

Timothy McCartin

Christepher McKenney

Tin Mo

Edward O’Donnell

Jacob Phillip

Phillip Reed

Makuteswara Srinivasan

Keith Eckerman of the Oak Ridge National Laboratory gave freely of his time in providing

advice and data on the external exposure calculations. The technical staff of the Carderock

Division, Naval Surface Warfare Center, were most helpful in providing data on ship

construction. T. Taylor Eighmy of the Recycled Materials Resource Center of the University of

New Hampshire, generously provided technical information and comments on the recycling of

concrete rubble. Ray Turner and Norb Geiss of The David J. Joseph Company contributed

invaluable insights and information on the scrap metal recycling industry. Nicholas Adams of

The Aluminum Association provided valuable data and explained many aspects of the secondary

aluminum industry. Timothy Miller of the Bethlehem Steel Corporation was most helpful in

providing information on BOF furnace operations.

Several commodity specialists from the U.S. Geological Survey were helpful in providing

information and discussing their published data. They include, in alphabetical order: 

Daniel Edelstein

Michael Fenton 

Rustu Kalyoncu

Patricia Plunkert

Hendrik van Oss

We would also like to thank two staff members U.S. Environmental Protection Agency for their

assistance Jim Maysilles, Metals Group, Emission Standards Division, who prepared data on

iron and steel foundries; and Paul Cassidy, Industrial and Extractive Branch, Office of Solid

Waste, who furnished data on hydrogeologic modeling parameters.
Acknowledgments

NUREG-1640 xxiv

Kathleen Theissen and David Kocher of SENES Oak Ridge Inc. served as peer reviewers of the

technical analyses presented in the report. 

A number of SC&A Associates made substantial scientific and technical contributions. They

include, in alphabetical order:

David Back

Nicole Briggs

Michele Sutton Ferenci

John Harrop

Nolan Hertel

Gary Huddleston

Janice Jolly

Anthony LaMastra

Michael Mallett

The entire SC&A staff provided their wholehearted support to this project. Our special thanks

go to the following:

Kathleen Behling

Judy Eley

Nancy Johnson

Laurie Loomis

A special recognition is given to the technical work of the principal authors of the draft report for

establishing the foundations for the analytical approaches: 

Michael McKenzie-Carter

Mark Otis

Mary Anderson

James Roberts

Reginald Gotchy
Abbreviations

xxv NUREG-1640

ABBREVIATIONS

AISE Association of Iron and Steel Engineers

AISI American Iron and Steel Institute

AMAD activity median aerodynamic diameter

APCD air pollution control device

AWG American wire gauge

BNL Brookhaven National Laboratory

BOF basic oxygen furnace

BWR boiling water reactor

C&D construction and demolition (landfill)

CFR Code of Federal Regulations

CZO crude zinc oxide

DCF dose conversion factor

DOE Department of Energy (U.S.)

DOT Department of Transportation (U.S.)

DRI direct reduced iron

EAF electric arc furnace

EC European Commission

EDE effective dose equivalent

EPA Environmental Protection Agency (U.S.)

EPRI Electric Power Research Institute

ESP electrostatic precipitator

FGR Federal Guidance Report

HRDC Horsehead Resource Development Company

HTMR high-temperature metals recovery

I&SS Iron & Steel Society 

IAEA International Atomic Energy Agency

ICRP International Commission on Radiological Protection

JIT just-in-time

LLRW low-level radioactive waste

MSW municipal solid waste

NCRP National Council on Radiation Protection and Measurement

NESHAP National Emission Standard for Hazardous Air Pollutants

NRC Nuclear Regulatory Commission (U.S.)

NWSW Northwestern Steel and Wire Company

OSHA Occupational Safety and Health Administration (U.S.)

PEL permissible exposure limit

PNL Pacific Northwest Laboratory

PWR pressurized water reactor

QA quality assurance

Q-BOP bottom-blown BOF

QMP Quality Management Plan

RCM recycled concrete material

RCRA Resource Conservation and Recovery Act
Abbreviations

NUREG-1640 xxvi

SAE Society of Automotive Engineers

SAIC Science Applications International Corporation

SC&A SC&A, Inc.

SCBA Self-contained breathing apparatus

TWA time-weighted average

UBC used beverage can

UNREP underway replenishment (U.S. Navy)

USGS United States Geological Survey
Chapter 1 Introduction

1-1 NUREG-1640

This is a report of the assessments of potential radiation doses to individuals from the recycling or

disposal of solid materials that could be cleared from nuclear facilities. The assessments address four

types of material: steel, copper and aluminum scrap, and concrete rubble. The exposures of

individuals to such materials at key steps in recycling and disposal are characterized by exposure

scenarios. These exposures are assessed to identify the critical groups for each of 115 radionuclides

that are potential components of the residual radioactivity of such materials. The results are normalized

to initial unit activity concentrations of each separate radionuclide in each material, and are expressed

in terms of the effective dose equivalent (EDE) (ICRP 1977) and effective dose (ICRP 1991).

The group of individuals with the highest mean EDE or effective dose from a given nuclide is

designated the EDE- or effective dose-critical group for that nuclide. Four sets of critical groups—one

for each of the four types of materials—are identified for each nuclide. In addition to the mean values,

the 5th, 50th, 90th, and 95th percentile values of EDE and effective dose in each exposure scenario via

each pathway are presented and discussed in subsequent sections of the report.

The calculations are designed to be realistic. To the extent possible, data on current U.S. industrial and

commercial practices are used to characterize the anticipated recycling and disposal of cleared

materials. The variability and uncertainty in the values of parameters characterizing these practices

and the physico-chemical processes of the melting and refining of scrap metals are expressed as

probability distributions. The parameter values used in the analysis are selected by Monte Carlo

sampling of these distributions, resulting in distributions of estimated normalized EDEs and effective

doses. 

1 INTRODUCTION

Clearance (unrestricted release from regulatory control) of materials is defined as the removal of

all radiological restrictions on the use or disposal of such materials. Of the many possible fates

of such materials, it is most likely that they would be processed for recycling or, at the option of

the licensee, disposed of in a landfill. The radiological assessment of the recycling or disposal of

cleared materials is presented in the following chapters of this report.

1.1 Purpose and Scope

The purpose of the present analysis is to assess the potential radiation exposures of individuals

resulting from the clearance of materials from NRC- and Agreement State-licensed facilities. 

The analysis addresses the clearance of iron and steel scrap, scrap aluminum, scrap copper, and

concrete rubble. These categories comprise the bulk of components that would be potentially

cleared from licensed facilities.

The end points of the analysis are the effective dose equivalent (EDE) (ICRP 1977) and the

effective dose (ICRP 1991) from one year of exposure, normalized to an initial unit activity

concentration of each separate radionuclide in each material at the time of clearance. The EDE

and the effective dose are calculated separately—in the subsequent discussions, unless otherwise

specified, the term “dose” encompasses both EDE and effective dose. Calculation of both EDE

and effective dose are required for appropriate comparisons within the current regulatory

context, which is based on the recommendations in ICRP Publication 26 (ICRP 1977), and with

the more current approaches of the European Commission, the International Atomic Energy
Introduction Chapter 1

1

 The specific activity is an average value that applies to the entire batch of cleared material in a particular analysis. 

It is derived by dividing the total initial activity of a given batch of cleared material by the total mass of that material.

2

 It should be noted, however, that these are 50-y committed doses per year of exposure, not annual dose rates.

NUREG-1640 1-2

Agency, and the U.S. Environmental Protection Agency’s Federal Guidance Report No. 13

(Eckerman et al. 1999), all of which are based on the recommendations in ICRP Publication 60

(ICRP 1991).

At the time the materials are cleared, the residual activities could either reside on the surface or

be distributed throughout the volume of bulk material. In either case, the radiation exposure of

an individual to batches of material, which consist of many individual components of differing

sizes and shapes, can be approximated by assuming an average uniform distribution of the

activity in the entire mass. The doses calculated in this analysis are normalized to mass activity

concentrations (specific activities).1

 A second calculation is performed to derive doses

normalized to areal activity concentrations by dividing the mass-based normalized doses by the

mass-to-surface ratio specific to each of the four materials. Thus, the results of the analysis are

reported as both mass-based (:Sv per Bq/g) and surficial normalized doses (:Sv per Bq/cm2). 

These doses are integrated over the period of assessment. Since the analysis assesses the doses

over a period of one year, these become normalized doses from exposures occurring during this

one-year period, and can be expressed in :Sv/y.2

The design objective is to realistically estimate the mean dose to individual members of the

critical group from each radionuclide that is a potential component of the residual radioactivities

of cleared materials. The critical group is defined in 10 CFR 20.1003 as “the group of

individuals reasonably expected to receive the greatest exposure to residual radioactivity for any

applicable set of circumstances.” 

1.2 Exposure Scenarios

The focal point of the analysis is identifying the critical group for each radionuclide in the four

types of cleared materials listed in Section 1.1, above. Situations in which individuals are likely

to be exposed to the residual radioactivities in cleared materials can be characterized by

exposure scenarios. 

The range of possible scenarios is virtually unlimited. It includes all known or potential uses of

cleared materials, and the many processes by which such material can be recycled or disposed of. 

The scenarios selected for the analysis represent current U.S. industrial and commercial

practices. The scenarios were selected to encompass the likely critical groups for each

radionuclide in each type of material in the present analysis. Since the purpose of the analysis is

to characterize the exposures of critical groups, which comprise significant numbers of

individuals, unlikely scenarios, or those involving only a very few individuals, were excluded. 
Chapter 1 Introduction

1-3 NUREG-1640

1.3 Parameter Values

Each exposure scenario is characterized by a set of parameters that constitute a mathematical

description of that scenario. Examples of such parameters include the average hours of exposure

to the source of radiation, such as the hours per week a truck driver hauling cleared material

spends in the cab of his truck, and the average concentration of airborne dust generated by the

processing of steel scrap. The analysis of iron and steel scrap alone includes over 300

radionuclide-independent parameters—those parameters that are applicable to the assessments of

all radionuclides.

Each scenario models the exposure of a group of individuals to the residual activity of a given

medium. The concentration of a given radionuclide in such a medium is the result of one or

more processes: the mixing of cleared material (e.g., scrap metal) with similar material from

sources other than nuclear facilities, the melt-refining of scrap metal by a secondary metal

producer, the commingling of material disposed of in a landfill with wastes from other sources,

etc. Each of these processes is characterized by additional parameters.

Many of the parameters employed in the analysis are estimates based on published sources or

industry contacts. Some references (e.g., EPA 1997a) present parameter values (e.g., the daily

consumption of drinking water) in the form of frequency distributions. Other sources may

present minimum, maximum, and average values of certain parameters. In still other cases, a set

of discrete values is obtained from one or more sources. 

Some parameters have fixed values. Among these are physical constants (e.g., radioactive halflives) and radiobiological parameters (e.g., dose conversion factor for the intake of each

radionuclide). Fixed parameters, such as the distance from the source of airborne effluent

emissions to the receptor location, are also used to define particular scenarios.

1.3.1 Probabilistic Analyses

In the present analysis, a parameter that does not have a single fixed value is characterized by a

probability distribution. The forms of these distributions are discussed and presented in the

following chapters. A general discussion of the types of probability distributions used in the

present analysis and a listing of the values and distributions of each parameter are presented in

Appendix B.

Each individual calculation, whether it is the assessment of a radiation dose in a given scenario

or the concentration of a given radionuclide in a given medium, is deterministic—it employs a

set of fixed values of the relevant parameters and produces a fixed result. For parameters that

are uncertain or variable, Monte Carlo sampling methods are used to pick the particular set of

values in a given calculation, called a realization. In the present analysis, the estimation of each

dose, radionuclide concentration, or other intermediate parameter involved between 5,800 and

10,000 realizations. These 5,800 – 10,000 results themselves form a probability distribution. 

The mean value and the 5th, 50th, 90th, and 95th percentile values of each such distribution are

listed in subsequent parts of the present report.
Introduction Chapter 1

NUREG-1640 1-4

Figure 1.1 Frequency distributions of normalized doses from a hypothetical source

In all cases where an intermediate parameter is calculated using Monte Carlo sampling methods,

each of the calculated values is used as input to the next step in the calculation. For example,

although the mean and the 5th, 50th, 90th, and 95th percentile values of concentrations of

radionuclides are listed in Appendix K, these are solely for the information of the reader. In

estimating a radiation dose using 10,000 realizations, for instance, each realization uses each of

10,000 radionuclide concentrations in succession.

This probabilistic approach follows the general guidance of the U.S. Environmental Protection

Agency’s Guiding Principles for Monte Carlo Analysis (EPA 1997b), NCRP Commentary

Number 14 (NCRP 1996), and IAEA Safety Series Number 100 (IAEA 1989).

1.4 Critical Groups

The critical group for each radionuclide in each of the four types of cleared materials is the

group receiving the highest mean dose from among all the exposure scenarios addressing the

given type of material. Since EDEs and effective doses were calculated separately, there are

both EDE- and effective-dose critical groups. In most but not all cases, the same scenario

characterizes both the EDE- and effective dose-critical group for a given radionuclide in a given

material. Between eight and 30 scenarios are analyzed and compared for each material.

Figure 1.1 depicts an idealized diagram of frequency distributions of normalized doses from

some hypothetical source to members of six hypothetical groups, including the critical group, as

well as to the entire U.S. population. (This diagram is solely for the purposes of illustration and

does not represent actual results of the present analysis.) The number of individuals receiving a

given dose is plotted along the vertical axis. Because of the variability of exposure parameters

discussed in Section 1.3, the doses to individual members of each group will also vary. 

As described by the International Commission on Radiation Protection (ICRP 1985): 
Chapter 1 Introduction

3

 Robert A. Meck, NRC, letter to Gordon Linsley, Scientific Secretary, Division of Nuclear Fuel Cycle and Waste

Management, International Atomic Energy Agency, November 9, 1992.

1-5 NUREG-1640

The [critical] group should be representative of those individuals in the population expected

to receive the highest dose . . . . The Commission [i.e., the ICRP] believes that it will be

reasonable to apply the appropriate dose-equivalent limit for individual members of the

public to the mean dose equivalent in the critical group [italics added for emphasis]. 

Most members of the public will not be exposed to this hypothetical source and will receive a

dose that is essentially zero. That segment of the population is not depicted in Figure 1.1. The

dotted curve represents the doses to all members of the public, including the six groups

represented by the solid curves. The dotted curve indicates that there are some exposed

individuals that are not included in any of the six groups examined in this hypothetical analysis. 

Furthermore, there are a few individuals who, perhaps due to aberrant behavior, unusual habits

or work practices, etc., could potentially receive doses that are higher than those received by

members of the critical group. Such individuals are not within the scope of the present analysis.

1.5 Radionuclide Selection

A key step in the analyses is identifying the radionuclides that are potential components of the

residual radioactivities of cleared materials. These 115 nuclides are selected from a number of

references, which are discussed below. Table 1.1 presents a list of these nuclides and presents

the basis for their selection.

NRC Correspondence with IAEA.

3

 Radionuclides constituting the residual activities in

cleared material are likely to be similar to those in low-level radioactive waste. Radionuclides

listed in this correspondence constitute more than 90% of the total activities disposed of at U.S.

commercial LLRW disposal sites during the three years: 1988 – 1990.

1992 State-by-State Assessment of Low-Level Radioactive Wastes Received at Commercial

Disposal Sites (Fuchs and McDonald 1993). This document lists radionuclides in wastes from

various sources—indirect (shipments from the generator to the disposal facility through an

intermediary), reactors, academic, medical, industrial, and government—that were disposed of at

commercial LLRW disposal sites in 1992.

Radionuclides in United States Commercial Nuclear Power Reactors (Dyer 1995). This

article presents data from several studies on the radionuclide inventories found in nuclear power

plant systems and materials (specifically stainless steel). The study included only those

radionuclides with half-lives longer than 50 days.

Activation products. Activation products likely to be found in or on cleared materials as a

result of neutron irradiation were added to the list of radionuclides.
Introduction Chapter 1

NUREG-1640 1-6

Table 1.1 Radionuclides of interest in the analysis of recycling and disposal of cleared materials

H-3 a Co-58 a Tc-97 f Cs-135 f W-185 f U-234 e Cm-244 c

C-14 a Co-60 a Tc-97m f Cs-137 a Os-185 f U-235 b Cm-245 f

Na-22 a Ni-59 b Tc-99 a Ba-133 b Ir-192 b U-236 f Cm-246 f

P-32 a Ni-63 a Ru-103 a Ce-139 f Tl-204 f U-238 a Cm-247 f

S-35 a Zn-65 a Ru-106 a Ce-141 a Pb-210 e Np-237 e Cm-248 f

Cl-36 a As-73 f Ag-108m c Ce-144 a Bi-207 f Pu-236 f Bk-249 f

K-40 b Se-75 a Ag-110m a Pm-147 a Po-210 a Pu-238 c Cf-248 f

Ca-41 d Sr-85 b Cd-109 b Sm-151 f Ra-226 f Pu-239 c Cf-249 f

Ca-45 a Sr-89 c Sn-113 f Eu-152 b Ra-228 f Pu-240 c Cf-250 f

Sc-46 f Sr-90 a Sb-124 a Eu-154 b Ac-227 e Pu-241 a Cf-251 f

Cr-51 a Y-91 c Sb-125 b Eu-155 c Th-228 b Pu-242 f Cf-252 f

Mn-53 f Zr-93 f Te-123m f Gd-153 f Th-229 e Pu-244 f Cf-254 f

Mn-54 a Zr-95 a Te-127m f Tb-160 f Th-230 e Am-241 b Es-254 f

Fe-55 a Nb-93m c I-125 a Tm-170 f Th-232 a Am-242m f

Fe-59 a Nb-94 c I-129 a Tm-171 f Pa-231 e Am-243 f

Co-56 f Nb-95 a I-131 a Ta-182 f U-232 f Cm-242 c

Co-57 a Mo-93 c Cs-134 a W-181 f U-233 e Cm-243 f

 a NRC correspondence with IAEA 

 b Fuchs and McDonald (1993)

 c Dyer (1995)

 d activation product

 e radioactive progeny

 f EC 1998

Radioactive progeny of radionuclides on the list. Potentially significant (half-life greater than

30 days) radioactive progeny from parent radionuclides identified in the sources listed above

were explicitly included on the list. Radioactive progeny with half-lives of less than 30 days are

assumed to be in secular equilibrium with their parents (as described in Appendix E), and are

therefore implicitly included in the analysis of the parents.

Radiation Protection 89 (EC 1998). Radionuclides were included if they were addressed in the

European Commission’s recommended radiological protection criteria for recycling of metals

from nuclear installations.

Radionuclides excluded. Radionuclides with half-lives longer than that of Th-232 (greater than

1.41 × 1010 years) were not included in the analysis. The specific activities of such nuclides

(e.g., Sm-147) would be so low that no significant doses would result from the limited amounts

that would be found in cleared materials. With the exception of P-32 and I-131, nuclides with

half-lives of less than 30 days were also excluded. It is unlikely that any significant activities of

such short-lived nuclides would be found on cleared materials. The two afore-mentioned

nuclides were included because of their uses in medicine and research, and because I-131 is a

major fission product. 
Chapter 1 Introduction

1-7 NUREG-1640

1.1

1.6 Exposure Pathways

In each exposure scenario, the radiation dose can be delivered via one or more pathways. The

pathways included in the present analysis fall into two categories—external and internal—which

are discussed in the following sections.

1.6.1 External Exposure

All but three of the radionuclides in the present analysis—the exceptions are H-3, Ca-41 and

Mn-53—emit calculable photon radiation, as either - or x-rays emitted during the radioactive

decay of the atomic nucleus, or bremsstrahlung x-rays generated following -decay. The

external exposure to this direct, penetrating radiation is assessed in each scenario in which

individuals are in proximity to residually radioactive materials. 

The dose rate from external exposure for a given source is calculated as follows:

dix = dose rate from external exposure to nuclide i (:Sv/h)

Ci = activity concentration of nuclide i in source material (Bq/g)

Fix = dose coefficient for external exposure to nuclide i (:Sv/h per Bq/g)

Ux = uncertainty factor

The parameter Fix is a nuclide- and scenario-specific dose rate factor. When the source is

relatively compact or has a complex geometry, the values of Fix are derived by means of a

computer simulation of the emission of photons and -rays from the source, which has a

prescribed shape, dimensions, density, and elemental composition. The simulation, which

utilizes the Los Alamos Monte Carlo code, MCNP Version 4C, includes the interaction of these

emitted particles with the source material and with other objects and environmental media in the

vicinity, such as air, underlying soil or pavement, and other materials that shield or scatter the

radiation. The source is assumed to be uniformly contaminated throughout its mass with one of

the 115 radionuclides, along with its short-lived progeny. In most cases, the dose rates for each

exposure geometry are calculated at two or more receptor locations. These dose rates are then

combined to determine a rate at the desired location. The variation of dose rate with position is

used to calculate an uncertainty factor, Ux. This factor is assigned a uniform distribution with a

mean value, = 1. In some scenarios, the receptor location is assumed to be fixed. In still

other scenarios, the calculation is averaged over the occupied area or volume. In those cases,

Ux / 1. The calculation of Fix and Ux are discussed in greater detail in Appendix C. 

Two sets of calculations are performed for each exposure geometry and source material. The

EDE coefficients are calculated using the tissue weighting factors of ICRP Publication 26 (ICRP

1977), while effective dose coefficients utilize the ICRP 60 factors (ICRP 1991).
Introduction Chapter 1

NUREG-1640 1-8

Extended sources that can be approximated by an infinite plane utilize dose coefficients listed in

Federal Guidance Report (FGR) No. 12 (Eckerman and Ryman 1993), which includes EDE

coefficients for semi-infinite slabs of soil contaminated on the surface, as well as for soil

contaminated to an infinite depth. Effective dose coefficients for the same sources, based on the

FGR 12 calculations but employing ICRP 1991 tissue weighting factors, are listed in EPA 2000. 

The values of Fix derived from the FGR 12 coefficients are listed in Appendix B of the present

report. The value of Ux used for such sources is based on engineering judgment, and is discussed

as part of the description of the relevant scenarios.

Other external exposure pathways, such as the external exposure from a cloud of resuspended

aerosols or from a plume of airborne effluent emissions from a furnace recycling cleared metal

scrap, would make insignificant contributions to the dose assessments and are not included in the

present analysis.

1.6.2 Internal Exposure

The detailed discussion of the assessment of internal exposures due to the inhalation and

ingestion of residually radioactive material is presented in the sections describing the various

scenarios later in this report. Federal Guidance Report (FGR) No. 11 (Eckerman et al. 1988)

lists dose conversion factors (DCFs) for inhalation and ingestion that relate the intake of a unit

activity of a given radionuclide to the EDE to the individual. Similarly, ICRP Publication 68

(ICRP 1994) lists effective dose coefficients for intakes of radionuclides by workers. Since, as

will be seen in later chapters of this report, the critical groups for a large majority of the

radionuclides comprise workers, these are the appropriate coefficients for use in the present

analysis.

For many radionuclides, DCFs and effective dose coefficients have different values, depending

on the chemical form of the nuclide. ICRP 1994 further distinguishes the coefficients for

inhalation on the basis of particle size. In order to perform realistic assessments, the DCFs and

dose coefficients in each scenario were selected on the basis of the most likely chemical form of

each radionuclide in a given medium and the most likely particle size of the suspended aerosols

in that scenario. These chemical forms and particle sizes are discussed in greater detail in

Appendix L. The DCFs and dose coefficients assigned to each radionuclide in each medium are

listed in Appendix B.
Chapter 1 Introduction

1-9 NUREG-1640

References

Code of Federal Regulations, Title 10, Energy, Part 20, “Standards for Protection Against

Radiation,” Subpart A—“General Provisions,” 20.1003 “Definitions.” 

http://www.nrc.gov/reading-rm/doc-collections/cfr/part020/full-text.html (May 2, 2003).

Dyer, N. C. 1995. “Radionuclides in United States Commercial Nuclear Power Reactors.”

Radiation Protection Management, 12(1).

Eckerman, K. F., A. B. Wolbarst, and A. C. B. Richardson. 1988. “Limiting Values of

Radionuclide Intake and Air Concentration and Dose Conversion Factors for Inhalation,

Submersion, and Ingestion,” Federal Guidance Report No. 11, EPA-520/1-88-020. Washington,

DC: U.S. Environmental Protection Agency, Office of Radiation Programs.

Eckerman, K. F., and J. C. Ryman. 1993. “External Exposure to Radionuclides in Air, Water,

and Soil,” Federal Guidance Report No. 12, EPA 402-R-93-081. Washington, DC: U.S.

Environmental Protection Agency, Office of Radiation and Indoor Air.

Eckerman, K. F., et al. 1999. “Cancer Risk Coefficients for Environmental Exposure to

Radionuclides,” Federal Guidance Report No. 13, EPA 402-R-99-001. Washington, DC: U.S.

Environmental Protection Agency, Office of Radiation and Indoor Air.

Environmental Protection Agency (U.S.) (EPA). 1997a. “Exposure Factors Handbook,”

EPA/600/P-95/002Fa. Washington, DC: Author.

Environmental Protection Agency (U.S.) (EPA). 1997b. “Guiding Principles for Monte Carlo

Analysis,” EPA/630/R-97/001. Washington, DC: Author.

Environmental Protection Agency (U.S.) (EPA). 2000. “Federal Guidance Report 13: Cancer

Risk Coefficients for Environmental Exposures to Radionuclides.” CD Supplement, EPA-402-C99-001. Washington DC: Author.

European Commission (EC). 1998. “Recommended Radiological Protection Criteria for the

Recycling of Metals from the Dismantling of Nuclear Installations,” Radiation Protection 89.

Luxembourg: Office for Official Publications on the European Communities.

Fuchs, R. L., and S. D. McDonald. 1993. “1992 State-by State Assessment of Low-Level

Radioactive Wastes Received at Commercial Disposal Sites,” DOE/LLW-181. Washington DC:

U.S. Department of Energy.

International Atomic Energy Agency (IAEA). 1989. “Evaluating the Reliability of Predictions

Made Using Environmental Transfer Models,” Safety Series No. 100. Vienna: Author.

International Commission on Radiological Protection (ICRP). 1977. “Recommendations of the

ICRP,” ICRP Publication 26. Annals of the ICRP, 1(3). Oxford: Pergamon Press.
Introduction Chapter 1

NUREG-1640 1-10

International Commission on Radiological Protection (ICRP). 1985. “Principles of Monitoring

for the Radiation Protection of the Population,” ICRP Publication 43. Annals of the ICRP, 15(1). 

Oxford: Pergamon Press.

International Commission on Radiological Protection (ICRP). 1991. “1990 Recommendations of

the ICRP,” ICRP Publication 60. Annals of the ICRP, 21(1-3). Oxford: Pergamon Press.

International Commission on Radiological Protection (ICRP). 1994. “Dose Coefficients for

Intakes of Radionuclides by Workers,” ICRP Publication 68. Annals of the ICRP, 24(4). 

Tarrytown, NY: Elsevier Science, Inc.

National Council on Radiation Protection and Measurement (NCRP). 1996. “A Guide for

Uncertainty Analysis in Dose and Risk Assessments Related to Environmental Contamination,”

NCRP Commentary No. 14. Bethesda, MD: Author.
Chapter 2 Summary of Results

2-1 NUREG-1640

Radiological assessments of 79 exposure scenarios have been performed in order to identify the critical

groups for each of 115 radionuclides that are potential components of the residual radioactivities of steel,

copper and aluminum scrap, and concrete rubble. Monte Carlo sampling methods were used to calculate

distributions of effective dose equivalents (EDEs) and effective doses from each radionuclide in each of

the four materials. The results are normalized to initial unit activity concentrations in the cleared material

and are expressed as both mass-based and surficial doses (e.g., :Sv/y per Bq/g or :Sv/y per Bq/cm2

). 

The highest mass-based normalized doses from about 80% of the radionuclides are from the clearance of

concrete rubble, the critical group for about 40 of these nuclides comprising workers using the rubble for

road construction. The highest mean mass-based normalized EDE is1,400 :Sv/y per Bq/g from Cf-254. 

The critical group comprises workers processing concrete rubble. The corresponding mass-based

effective dose (from the same nuclide) has the same value. The highest mean surficial normalized EDE is

69 :Sv/y per Bq/cm2

 from Th-229. The critical group comprises workers processing copper slag. The

highest mean surficial normalized effective dose is 64 :Sv/y per Bq/cm2

 from I-129. The critical group is

the individuals drinking water from wells down gradient from a storage pile of steel slag.

2 SUMMARY OF RESULTS

The results of the analyses of the clearance of solid materials from NRC-licensed facilities are

used to identify the critical groups for each of 115 radionuclides in four types of cleared

materials: steel, copper and aluminum scrap, and concrete rubble. The mean doses to the

members of each of these critical groups, normalized to initial unit activity concentrations in the

cleared material, are presented in this chapter. Comparisons are presented of the mean massbased and surficial normalized doses from each radionuclide in the four types of materials. 

2.1 Summary of Effective Dose Equivalents (EDEs)

Table 2.1 presents the mean values of normalized effective dose equivalents (EDEs) to the

critical groups. The mass-based EDEs from each material are listed on the left-hand side of the

table—the highest mean dose from among the four materials is displayed in boldface type. The

corresponding surficial EDEs are displayed on the right-hand side. 

2.1.1 Mass-based EDEs 

The highest mean mass-based normalized EDEs from 88 of the 115 radionuclides are from the

clearance of concrete rubble. Forty-one of the critical groups for these nuclides in this material

are road construction workers using cleared concrete rubble as the base for the pavement and as

part of the aggregate in the asphaltic concrete. The remaining critical groups are workers

processing concrete for recycling or disposal or individuals drinking water from wells down

gradient from landfills used for the disposal of cleared concrete rubble.

The main reason why cleared concrete rubble accounts for the preponderance of the critical

groups is the large quantities of this material that would be generated during the dismantlement

of a large nuclear facility, such as a commercial nuclear power plant. As discussed in Chapter 6

and documented in greater detail in Appendix A, such a facility would generate between 143 and

281 kt of cleared concrete rubble. The quantities of other materials from such a plant would be
Summary of Results Chapter 2

1

 The abbreviation “t” stands for metric tons (tonnes); kilotonnes are abbreviated as “kt,” megatonnes as “Mt.” 

Tonnes can also be expressed as megagrams (Mg).

NUREG-1640 2-2

far smaller: between 15 and 24 kt1 of cleared steel scrap and much smaller quantities of other

metals. The large amount of concrete rubble would most likely be processed at or near the site

of the plant undergoing dismantlement, and is not likely to be mixed with concrete material from

other sources. Thus, workers would be exposed to the undiluted residual activity concentrations

in the cleared material.

The highest mean mass-based EDEs for the remaining 27 nuclides are from the recycling of steel

scrap. Almost all of the critical groups for these nuclides comprise workers handling or

processing slag that is a byproduct of iron- and steelmaking furnaces.

2.1.2 Surficial EDEs 

The highest mean surficial EDEs from 74 of the 115 nuclides are from the recycling or disposal

of steel scrap. Most of the critical groups for this material are workers processing scrap at a

scrap yard. The reason why different materials are responsible for mass-based and surficial

normalized doses stems from the definition of the normalized surficial dose. As stated in

Section 1.1, each surficial dose is derived by dividing the corresponding mass-based normalized

dose by the mass-to-surface ratio of the material in question. The 10,000 realizations of the

mass-to-surface ratio for steel yield a mean of approximately 5.1 g/cm2

, while the corresponding

value for concrete is 280 g/cm2. This approximately 50-fold difference is why the clearance of

steel scrap yields the highest mean surficial EDEs.

The highest mean surficial EDEs from the remaining 41 nuclides are from the recycling of

copper scrap. These critical groups comprise workers processing copper slag at a secondary firerefining facility.

2.2 Summary of Effective Doses

Table 2.2, which presents the mean values of normalized effective doses, has the same structure

as Table 2.1. The highest mass-based normalized effective doses from 95 nuclides are from the

clearance of concrete rubble. The reasons for the dominance of this material are the same as

those for the EDE-critical groups discussed in Section 2.1.1.

For the remaining 20 nuclides, the highest mass-based normalized effective doses are from the

recycling of steel scrap. Almost all of these critical groups comprise workers handling or

processing scrap or slag. 

The highest surficial effective doses are from the recycling or disposal of steel scrap for 87 of the

115 nuclides, for the same reasons as were discussed for the surficial EDE-critical groups in

Section 2.1.2. For the remaining 28 nuclides, the highest surficial effective doses are from the

recycling of copper scrap. 
Chapter 2 Summary of Results

2-3 NUREG-1640

Table 2.1 Normalized effective dose equivalents to critical groups for all materials

Radionuclide

Mass-based (:Sv/y per Bq/g) Surficial (:Sv/y per Bq/cm2)

Steel Copper Aluminum Concrete Steel Copper Aluminum Concrete

H-3 1.9e-02 1.0e-04 2.8e-06 6.6e-02 3.8e-03 2.0e-04 3.1e-06 2.4e-04

C-14 3.2e-02 2.4e-04 4.5e-06 1.2e-01 6.3e-03 4.7e-04 5.0e-06 4.1e-04

Na-22 4.2e+01 1.2e+00 2.9e-02 2.4e+02 8.3e+00 2.3e+00 3.2e-02 8.5e-01

P-32 5.7e-02 7.9e-04 2.1e-05 1.1e-01 1.1e-02 1.5e-03 2.4e-05 3.8e-04

S-35 3.7e-04 2.7e-05 8.2e-07 1.6e-03 7.4e-05 5.3e-05 9.2e-07 5.7e-06

Cl-36 1.7e+00 2.1e-03 5.9e-05 1.3e+00 3.4e-01 4.0e-03 6.6e-05 4.7e-03

K-40 3.4e+00 6.5e-02 2.2e-03 1.9e+01 6.7e-01 1.3e-01 2.5e-03 6.7e-02

Ca-41 2.1e-01 1.1e-03 2.9e-05 7.2e-01 4.2e-02 2.2e-03 3.2e-05 2.6e-03

Ca-45 2.0e-03 2.2e-04 3.8e-06 1.1e-02 4.0e-04 4.3e-04 4.3e-06 3.9e-05

Sc-46 3.8e+01 9.3e-01 2.3e-02 1.7e+02 7.4e+00 1.8e+00 2.6e-02 5.9e-01

Cr-51 3.8e-01 8.2e-03 2.4e-04 1.8e+00 7.6e-02 1.6e-02 2.7e-04 6.3e-03

Mn-53 8.8e-04 1.4e-05 6.7e-07 1.5e-03 1.7e-04 2.6e-05 7.4e-07 5.5e-06

Mn-54 1.6e+01 4.3e-01 5.6e-02 8.5e+01 3.2e+00 8.4e-01 6.3e-02 3.0e-01

Fe-55 4.6e-04 4.3e-05 3.1e-06 2.1e-03 9.1e-05 8.4e-05 3.5e-06 7.6e-06

Fe-59 2.1e+01 4.4e-01 1.2e-02 8.8e+01 4.2e+00 8.4e-01 1.4e-02 3.1e-01

Co-56 6.8e+01 1.3e+00 4.8e-02 3.0e+02 1.3e+01 2.5e+00 5.3e-02 1.1e+00

Co-57 1.2e+00 1.5e-02 7.2e-03 8.1e+00 2.4e-01 2.9e-02 8.0e-03 2.9e-02

Co-58 1.7e+01 3.5e-01 1.3e-02 7.5e+01 3.3e+00 6.8e-01 1.4e-02 2.7e-01

Co-60 5.2e+01 1.1e+00 2.6e-01 2.9e+02 1.0e+01 2.2e+00 2.9e-01 1.0e+00

Ni-59 4.6e-04 2.8e-05 2.2e-06 2.1e-03 9.1e-05 5.4e-05 2.5e-06 7.6e-06

Ni-63 4.7e-04 5.4e-05 3.5e-06 2.1e-03 9.4e-05 1.0e-04 3.9e-06 7.4e-06

Zn-65 1.5e+01 2.7e-01 3.1e-02 5.9e+01 3.0e+00 5.3e-01 3.5e-02 2.1e-01

As-73 2.2e-02 1.7e-04 1.8e-05 1.2e-01 4.4e-03 3.2e-04 2.0e-05 4.4e-04

Se-75 5.9e+00 6.5e-02 1.0e-02 2.8e+01 1.2e+00 1.3e-01 1.1e-02 1.0e-01

Sr-85 7.6e+00 2.0e-01 5.1e-03 3.6e+01 1.5e+00 3.9e-01 5.7e-03 1.3e-01

Sr-89 6.3e-02 1.2e-03 2.9e-05 1.4e-01 1.2e-02 2.2e-03 3.3e-05 5.0e-04

Sr-90 5.7e-01 1.3e-02 2.6e-04 1.5e+00 1.2e-01 2.6e-02 2.9e-04 5.2e-03

Y-91 1.4e-01 3.5e-03 7.9e-05 4.3e-01 2.7e-02 6.7e-03 8.8e-05 1.5e-03

Zr-93 9.3e-03 1.7e-03 2.1e-05 9.4e-03 1.8e-03 3.4e-03 2.3e-05 3.3e-05

Zr-95 1.5e+01 4.4e-01 1.1e-02 8.6e+01 3.0e+00 8.6e-01 1.2e-02 3.1e-01

Nb-93m 3.3e-03 6.1e-04 7.3e-06 3.8e-03 6.6e-04 1.2e-03 8.1e-06 1.4e-05

Nb-94 3.0e+01 8.7e-01 2.0e-01 1.7e+02 6.0e+00 1.7e+00 2.2e-01 6.2e-01

Nb-95 1.2e+01 2.8e-01 7.1e-03 5.1e+01 2.4e+00 5.3e-01 7.9e-03 1.8e-01

Mo-93 3.7e-02 6.4e-04 9.0e-06 1.7e-01 7.3e-03 1.2e-03 1.0e-05 6.1e-04

Tc-97 1.9e-01 1.1e-03 3.0e-05 7.1e-01 3.7e-02 2.1e-03 3.3e-05 2.5e-03

Tc-97m 4.5e-03 1.6e-04 4.6e-06 2.7e-02 8.9e-04 3.1e-04 5.1e-06 9.7e-05

Tc-99 1.6e+00 9.5e-03 2.5e-04 6.1e+00 3.2e-01 1.8e-02 2.8e-04 2.2e-02

Ru-103 7.1e+00 1.1e-01 4.5e-03 3.2e+01 1.4e+00 2.2e-01 5.1e-03 1.2e-01

Ru-106 4.2e+00 8.0e-02 1.9e-02 2.2e+01 8.2e-01 1.5e-01 2.2e-02 7.7e-02
Summary of Results Chapter 2

Table 2.1 Normalized effective dose equivalents to critical groups for all materials

Radionuclide

Mass-based (:Sv/y per Bq/g) Surficial (:Sv/y per Bq/cm2)

Steel Copper Aluminum Concrete Steel Copper Aluminum Concrete

NUREG-1640 2-4

Ag-108m 2.9e+01 5.5e-01 2.4e-01 1.7e+02 5.7e+00 1.1e+00 2.7e-01 6.2e-01

Ag-110m 5.2e+01 9.7e-01 1.7e-01 2.8e+02 1.0e+01 1.9e+00 1.9e-01 9.8e-01

Cd-109 6.5e-02 1.5e-03 2.0e-04 4.8e-01 1.3e-02 2.9e-03 2.2e-04 1.7e-03

Sn-113 3.7e+00 9.1e-02 6.6e-03 2.1e+01 7.4e-01 1.8e-01 7.4e-03 7.4e-02

Sb-124 3.4e+01 5.8e-01 2.0e-02 1.5e+02 6.6e+00 1.1e+00 2.3e-02 5.2e-01

Sb-125 7.1e+00 1.6e-01 4.0e-02 4.3e+01 1.4e+00 3.1e-01 4.5e-02 1.5e-01

Te-123m 1.5e+00 1.3e-02 3.5e-03 9.0e+00 3.0e-01 2.6e-02 3.9e-03 3.2e-02

Te-127m 1.0e-01 1.5e-03 1.3e-04 4.8e-01 2.1e-02 2.9e-03 1.4e-04 1.7e-03

I-125 7.3e-01 1.5e-03 4.8e-05 2.5e-01 1.4e-01 3.0e-03 5.3e-05 8.8e-04

I-129 2.2e+02 4.0e-01 1.2e-02 2.9e+02 4.4e+01 7.8e-01 1.4e-02 1.0e+00

I-131 3.7e+00 3.6e-02 1.2e-03 1.0e+01 7.2e-01 7.1e-02 1.3e-03 3.6e-02

Cs-134 4.4e+01 5.5e-01 2.0e-02 1.6e+02 8.6e+00 1.1e+00 2.3e-02 5.8e-01

Cs-135 8.2e-03 8.6e-05 6.8e-06 2.6e-02 1.7e-03 1.7e-04 7.6e-06 9.3e-05

Cs-137 1.6e+01 2.0e-01 7.4e-03 6.1e+01 3.2e+00 3.9e-01 8.3e-03 2.2e-01

Ba-133 4.9e+00 1.5e-01 4.2e-03 3.5e+01 9.7e-01 3.0e-01 4.7e-03 1.3e-01

Ce-139 1.5e+00 2.9e-02 1.2e-03 9.4e+00 3.0e-01 5.6e-02 1.3e-03 3.4e-02

Ce-141 7.1e-01 9.1e-03 4.4e-04 3.2e+00 1.4e-01 1.8e-02 4.9e-04 1.1e-02

Ce-144 1.0e+00 3.0e-02 7.3e-04 5.3e+00 2.0e-01 5.9e-02 8.1e-04 1.9e-02

Pm-147 4.4e-03 8.2e-04 9.9e-06 5.9e-03 8.6e-04 1.6e-03 1.1e-05 2.1e-05

Sm-151 3.3e-03 6.2e-04 7.2e-06 2.7e-03 6.4e-04 1.2e-03 8.0e-06 9.5e-06

Eu-152 2.2e+01 6.1e-01 1.5e-02 1.2e+02 4.3e+00 1.2e+00 1.7e-02 4.4e-01

Eu-154 2.2e+01 6.0e-01 1.5e-02 1.4e+02 4.3e+00 1.2e+00 1.7e-02 4.9e-01

Eu-155 4.5e-01 6.2e-03 3.4e-04 3.2e+00 8.8e-02 1.2e-02 3.8e-04 1.1e-02

Gd-153 5.9e-01 6.7e-03 4.3e-04 3.9e+00 1.2e-01 1.3e-02 4.7e-04 1.4e-02

Tb-160 2.0e+01 4.9e-01 1.2e-02 8.8e+01 3.9e+00 9.4e-01 1.4e-02 3.1e-01

Tm-170 3.6e-02 1.1e-03 3.1e-05 2.3e-01 7.1e-03 2.1e-03 3.4e-05 8.1e-04

Tm-171 2.7e-03 2.2e-04 4.1e-06 2.0e-02 5.4e-04 4.2e-04 4.6e-06 7.2e-05

Ta-182 2.3e+01 5.9e-01 2.7e-02 1.1e+02 4.6e+00 1.1e+00 3.0e-02 4.0e-01

W-181 1.8e-01 1.5e-03 3.1e-04 1.1e+00 3.6e-02 2.9e-03 3.4e-04 3.9e-03

W-185 2.0e-03 7.6e-05 2.1e-06 9.7e-03 4.0e-04 1.5e-04 2.3e-06 3.4e-05

Os-185 1.4e+01 2.0e-01 1.2e-02 5.6e+01 2.8e+00 3.9e-01 1.3e-02 2.0e-01

Ir-192 1.1e+01 1.9e-01 1.1e-02 5.8e+01 2.2e+00 3.7e-01 1.2e-02 2.1e-01

Tl-204 1.2e-02 1.9e-04 1.0e-04 7.8e-02 2.3e-03 3.7e-04 1.1e-04 2.8e-04

Pb-210 1.2e+01 3.9e-01 3.7e-02 2.5e+01 2.4e+00 7.5e-01 4.2e-02 9.1e-02

Bi-207 4.3e+01 5.5e-01 1.6e-01 1.7e+02 8.5e+00 1.1e+00 1.8e-01 6.0e-01

Po-210 3.3e+00 3.9e-02 3.1e-03 6.3e+00 6.6e-01 7.7e-02 3.5e-03 2.2e-02

Ra-226 3.5e+01 1.1e+00 2.6e-02 2.0e+02 7.0e+00 2.2e+00 2.9e-02 7.2e-01

Ra-228 1.8e+01 7.8e-01 1.5e-02 1.2e+02 3.6e+00 1.5e+00 1.7e-02 4.1e-01
Chapter 2 Summary of Results

Table 2.1 Normalized effective dose equivalents to critical groups for all materials

Radionuclide

Mass-based (:Sv/y per Bq/g) Surficial (:Sv/y per Bq/cm2)

Steel Copper Aluminum Concrete Steel Copper Aluminum Concrete

2-5 NUREG-1640

Ac-227 1.4e+02 2.7e+01 3.2e-01 1.4e+02 2.8e+01 5.3e+01 3.6e-01 5.0e-01

Th-228 4.9e+01 7.6e+00 7.7e-02 1.8e+02 9.7e+00 1.5e+01 8.6e-02 6.5e-01

Th-229 1.9e+02 3.6e+01 5.1e-01 1.3e+02 3.6e+01 6.9e+01 5.6e-01 4.8e-01

Th-230 2.7e+01 5.3e+00 7.6e-02 1.8e+01 5.4e+00 1.0e+01 8.4e-02 6.3e-02

Th-232 1.2e+02 2.4e+01 3.8e-01 8.9e+01 2.4e+01 4.6e+01 4.2e-01 3.2e-01

Pa-231 9.5e+01 1.8e+01 3.1e-01 9.7e+01 1.9e+01 3.4e+01 3.4e-01 3.4e-01

U-232 7.5e+01 1.3e+01 1.5e-01 3.7e+01 1.5e+01 2.6e+01 1.7e-01 1.3e-01

U-233 1.4e+01 2.7e+00 3.1e-02 3.2e+01 2.8e+00 5.3e+00 3.5e-02 1.1e-01

U-234 1.4e+01 2.7e+00 3.1e-02 2.3e+01 2.7e+00 5.2e+00 3.4e-02 8.1e-02

U-235 1.4e+01 2.6e+00 3.0e-02 3.3e+01 2.7e+00 5.0e+00 3.4e-02 1.2e-01

U-236 1.3e+01 2.5e+00 2.9e-02 2.1e+01 2.6e+00 4.9e+00 3.2e-02 7.5e-02

U-238 1.3e+01 2.4e+00 2.8e-02 2.1e+01 2.5e+00 4.7e+00 3.1e-02 7.5e-02

Np-237 3.2e+02 1.1e+01 1.3e-01 1.1e+03 6.2e+01 2.2e+01 1.5e-01 3.8e+00

Pu-236 1.4e+01 2.8e+00 3.4e-02 1.0e+01 2.7e+00 5.4e+00 3.8e-02 3.7e-02

Pu-238 3.1e+01 6.0e+00 9.3e-02 2.9e+01 6.1e+00 1.2e+01 1.0e-01 1.0e-01

Pu-239 3.3e+01 6.4e+00 1.0e-01 3.1e+01 6.6e+00 1.2e+01 1.1e-01 1.1e-01

Pu-240 3.3e+01 6.4e+00 1.0e-01 3.1e+01 6.6e+00 1.2e+01 1.1e-01 1.1e-01

Pu-241 5.8e-01 1.0e-01 2.0e-03 6.1e-01 1.1e-01 2.0e-01 2.2e-03 2.2e-03

Pu-242 3.2e+01 6.1e+00 9.7e-02 3.0e+01 6.2e+00 1.2e+01 1.1e-01 1.1e-01

Pu-244 3.5e+01 6.2e+00 1.0e-01 5.8e+01 6.8e+00 1.2e+01 1.1e-01 2.1e-01

Am-241 4.8e+01 9.1e+00 1.1e-01 3.3e+01 9.4e+00 1.8e+01 1.2e-01 1.2e-01

Am-242m 4.7e+01 9.0e+00 1.0e-01 3.3e+01 9.3e+00 1.8e+01 1.2e-01 1.2e-01

Am-243 4.8e+01 9.1e+00 1.1e-01 4.5e+01 9.5e+00 1.8e+01 1.2e-01 1.6e-01

Cm-242 1.6e+00 3.2e-01 3.8e-03 1.1e+00 3.2e-01 6.3e-01 4.2e-03 3.9e-03

Cm-243 3.3e+01 6.3e+00 7.4e-02 3.0e+01 6.6e+00 1.2e+01 8.2e-02 1.1e-01

Cm-244 2.6e+01 5.1e+00 5.9e-02 1.8e+01 5.2e+00 9.8e+00 6.5e-02 6.4e-02

Cm-245 4.9e+01 9.4e+00 1.1e-01 3.8e+01 9.7e+00 1.8e+01 1.2e-01 1.4e-01

Cm-246 4.8e+01 9.3e+00 1.1e-01 3.3e+01 9.5e+00 1.8e+01 1.2e-01 1.2e-01

Cm-247 4.7e+01 8.7e+00 1.0e-01 5.7e+01 9.3e+00 1.7e+01 1.1e-01 2.0e-01

Cm-248 1.8e+02 3.4e+01 3.9e-01 1.2e+02 3.5e+01 6.6e+01 4.4e-01 4.3e-01

Bk-249 1.5e-01 2.8e-02 3.3e-04 1.0e-01 2.9e-02 5.4e-02 3.6e-04 3.7e-04

Cf-248 5.1e+00 1.0e+00 1.2e-02 3.3e+00 1.0e+00 1.9e+00 1.3e-02 1.2e-02

Cf-249 4.4e+01 8.0e+00 9.6e-02 6.0e+01 8.7e+00 1.6e+01 1.1e-01 2.1e-01

Cf-250 2.2e+01 4.2e+00 4.9e-02 1.6e+01 4.3e+00 8.2e+00 5.5e-02 5.9e-02

Cf-251 4.3e+01 8.1e+00 9.4e-02 4.1e+01 8.4e+00 1.6e+01 1.1e-01 1.5e-01

Cf-252 1.6e+01 3.2e+00 3.7e-02 1.1e+01 3.2e+00 6.1e+00 4.1e-02 3.8e-02

Cf-254 3.3e+02 1.2e+01 2.5e-01 1.4e+03 6.5e+01 2.4e+01 2.7e-01 4.9e+00

Es-254 2.0e+01 1.3e+00 2.1e-02 9.2e+01 4.0e+00 2.5e+00 2.3e-02 3.3e-01

Note: To convert these values to conventional units (mrem/y per pCi/g or mrem/y per pCi/cm2

), multiply by 0.0037
Summary of Results Chapter 2

NUREG-1640 2-6

Table 2.2 Normalized effective doses to critical groups for all materials

Radionuclide

Mass-based (:Sv/y per Bq/g) Surficial (:Sv/y per Bq/cm2)

Steel Copper Aluminum Concrete Steel Copper Aluminum Concrete

H-3 2.0e-02 1.1e-04 2.9e-06 6.9e-02 4.0e-03 2.0e-04 3.2e-06 2.5e-04

C-14 3.3e-02 2.5e-04 4.6e-06 1.2e-01 6.5e-03 4.8e-04 5.1e-06 4.2e-04

Na-22 4.2e+01 1.1e+00 2.9e-02 2.2e+02 8.3e+00 2.2e+00 3.2e-02 8.0e-01

P-32 5.6e-02 7.8e-04 2.1e-05 1.1e-01 1.1e-02 1.5e-03 2.3e-05 3.8e-04

S-35 5.5e-04 4.2e-05 1.3e-06 1.9e-03 1.1e-04 8.1e-05 1.5e-06 6.7e-06

Cl-36 2.0e+00 2.3e-03 6.7e-05 1.5e+00 3.9e-01 4.5e-03 7.5e-05 5.3e-03

K-40 3.4e+00 6.5e-02 2.2e-03 1.8e+01 6.7e-01 1.3e-01 2.5e-03 6.4e-02

Ca-41 1.8e-01 9.5e-04 2.4e-05 6.1e-01 3.5e-02 1.9e-03 2.7e-05 2.2e-03

Ca-45 2.1e-03 2.5e-04 4.3e-06 1.0e-02 4.1e-04 4.8e-04 4.8e-06 3.6e-05

Sc-46 3.7e+01 9.1e-01 2.3e-02 1.7e+02 7.3e+00 1.8e+00 2.6e-02 5.9e-01

Cr-51 3.6e-01 7.9e-03 2.4e-04 1.8e+00 7.0e-02 1.5e-02 2.7e-04 6.3e-03

Mn-53 9.0e-04 6.3e-06 6.8e-07 1.6e-03 1.8e-04 1.2e-05 7.6e-07 5.6e-06

Mn-54 1.6e+01 4.2e-01 5.5e-02 8.0e+01 3.1e+00 8.2e-01 6.1e-02 2.8e-01

Fe-55 7.5e-04 6.0e-05 6.3e-06 4.2e-03 1.5e-04 1.2e-04 7.0e-06 1.5e-05

Fe-59 2.1e+01 4.3e-01 1.2e-02 8.9e+01 4.1e+00 8.3e-01 1.3e-02 3.2e-01

Co-56 6.7e+01 1.3e+00 4.7e-02 3.0e+02 1.3e+01 2.5e+00 5.2e-02 1.1e+00

Co-57 1.1e+00 1.5e-02 7.0e-03 7.4e+00 2.2e-01 2.8e-02 7.8e-03 2.6e-02

Co-58 1.7e+01 3.4e-01 1.2e-02 7.6e+01 3.3e+00 6.6e-01 1.4e-02 2.7e-01

Co-60 5.2e+01 1.1e+00 2.5e-01 2.7e+02 1.0e+01 2.1e+00 2.8e-01 9.7e-01

Ni-59 4.3e-04 1.9e-05 2.1e-06 2.2e-03 8.5e-05 3.6e-05 2.4e-06 7.9e-06

Ni-63 3.7e-04 3.4e-05 3.4e-06 2.0e-03 7.3e-05 6.6e-05 3.8e-06 7.0e-06

Zn-65 1.4e+01 2.7e-01 3.0e-02 5.6e+01 2.8e+00 5.2e-01 3.4e-02 2.0e-01

As-73 1.9e-02 1.4e-04 1.6e-05 1.0e-01 3.7e-03 2.7e-04 1.8e-05 3.7e-04

Se-75 5.5e+00 6.5e-02 1.0e-02 2.6e+01 1.1e+00 1.3e-01 1.1e-02 9.4e-02

Sr-85 7.6e+00 2.0e-01 5.1e-03 3.6e+01 1.5e+00 3.8e-01 5.7e-03 1.3e-01

Sr-89 6.2e-02 1.1e-03 2.9e-05 1.8e-01 1.2e-02 2.2e-03 3.2e-05 6.3e-04

Sr-90 4.2e-01 9.4e-03 1.9e-04 1.1e+00 8.8e-02 1.8e-02 2.1e-04 3.8e-03

Y-91 1.3e-01 3.0e-03 7.5e-05 4.5e-01 2.6e-02 5.8e-03 8.4e-05 1.6e-03

Zr-93 2.9e-03 5.3e-04 9.0e-06 4.6e-03 5.7e-04 1.0e-03 1.0e-05 1.6e-05

Zr-95 1.5e+01 4.3e-01 1.1e-02 8.1e+01 2.9e+00 8.4e-01 1.2e-02 2.9e-01

Nb-93m 6.2e-04 8.1e-05 2.7e-06 2.8e-03 1.2e-04 1.6e-04 3.1e-06 9.9e-06

Nb-94 3.0e+01 8.4e-01 1.9e-01 1.6e+02 5.9e+00 1.6e+00 2.1e-01 5.8e-01

Nb-95 1.2e+01 2.7e-01 7.0e-03 5.1e+01 2.4e+00 5.2e-01 7.8e-03 1.8e-01

Mo-93 1.9e-01 1.2e-03 5.2e-05 9.0e-01 3.8e-02 2.4e-03 5.8e-05 3.2e-03

Tc-97 3.3e-01 2.0e-03 5.3e-05 1.3e+00 6.6e-02 3.9e-03 6.0e-05 4.6e-03

Tc-97m 3.6e-03 2.8e-04 6.4e-06 2.8e-02 7.2e-04 5.3e-04 7.1e-06 9.9e-05

Tc-99 3.1e+00 1.9e-02 5.0e-04 1.2e+01 6.2e-01 3.6e-02 5.6e-04 4.3e-02

Ru-103 7.1e+00 1.1e-01 4.5e-03 3.3e+01 1.4e+00 2.2e-01 5.0e-03 1.2e-01

Ru-106 4.1e+00 7.8e-02 1.9e-02 2.1e+01 8.2e-01 1.5e-01 2.1e-02 7.4e-02
Chapter 2 Summary of Results

Table 2.2 Normalized effective doses to critical groups for all materials

Radionuclide

Mass-based (:Sv/y per Bq/g) Surficial (:Sv/y per Bq/cm2)

Steel Copper Aluminum Concrete Steel Copper Aluminum Concrete

2-7 NUREG-1640

Ag-108m 2.9e+01 5.4e-01 2.3e-01 1.6e+02 5.7e+00 1.1e+00 2.6e-01 5.8e-01

Ag-110m 5.2e+01 9.6e-01 1.7e-01 2.6e+02 1.0e+01 1.9e+00 1.9e-01 9.3e-01

Cd-109 5.5e-02 8.0e-04 2.0e-04 3.9e-01 1.1e-02 1.6e-03 2.2e-04 1.4e-03

Sn-113 3.7e+00 8.8e-02 6.4e-03 2.0e+01 7.4e-01 1.7e-01 7.2e-03 7.0e-02

Sb-124 3.3e+01 5.7e-01 2.0e-02 1.5e+02 6.6e+00 1.1e+00 2.2e-02 5.2e-01

Sb-125 7.0e+00 1.5e-01 3.9e-02 4.0e+01 1.4e+00 3.0e-01 4.3e-02 1.4e-01

Te-123m 1.4e+00 1.3e-02 3.4e-03 8.2e+00 2.7e-01 2.6e-02 3.8e-03 2.9e-02

Te-127m 9.7e-02 1.5e-03 1.2e-04 4.6e-01 1.9e-02 2.9e-03 1.4e-04 1.6e-03

I-125 1.0e+00 2.0e-03 6.3e-05 3.1e-01 2.0e-01 3.8e-03 7.0e-05 1.1e-03

I-129 3.3e+02 5.9e-01 1.8e-02 4.3e+02 6.4e+01 1.2e+00 2.0e-02 1.5e+00

I-131 3.4e+00 3.6e-02 1.2e-03 1.0e+01 6.7e-01 6.9e-02 1.3e-03 3.6e-02

Cs-134 4.1e+01 5.4e-01 2.0e-02 1.5e+02 8.0e+00 1.1e+00 2.2e-02 5.5e-01

Cs-135 8.6e-03 8.4e-05 6.6e-06 2.7e-02 1.8e-03 1.6e-04 7.4e-06 9.8e-05

Cs-137 1.5e+01 2.0e-01 7.4e-03 5.7e+01 3.0e+00 3.8e-01 8.2e-03 2.0e-01

Ba-133 4.9e+00 1.5e-01 4.2e-03 3.2e+01 9.6e-01 2.9e-01 4.7e-03 1.2e-01

Ce-139 1.4e+00 2.8e-02 1.2e-03 8.6e+00 2.8e-01 5.4e-02 1.3e-03 3.1e-02

Ce-141 6.5e-01 8.9e-03 4.4e-04 3.2e+00 1.3e-01 1.7e-02 4.9e-04 1.1e-02

Ce-144 9.9e-01 2.5e-02 6.9e-04 5.4e+00 2.0e-01 4.8e-02 7.7e-04 1.9e-02

Pm-147 1.7e-03 2.7e-04 4.7e-06 4.4e-03 3.3e-04 5.2e-04 5.3e-06 1.6e-05

Sm-151 1.1e-03 2.1e-04 3.4e-06 1.7e-03 2.2e-04 4.0e-04 3.8e-06 6.0e-06

Eu-152 2.2e+01 5.9e-01 1.5e-02 1.2e+02 4.3e+00 1.1e+00 1.7e-02 4.2e-01

Eu-154 2.1e+01 5.8e-01 1.5e-02 1.3e+02 4.2e+00 1.1e+00 1.6e-02 4.6e-01

Eu-155 4.0e-01 5.6e-03 3.4e-04 2.9e+00 7.8e-02 1.1e-02 3.8e-04 1.0e-02

Gd-153 5.2e-01 6.4e-03 4.2e-04 3.4e+00 1.0e-01 1.2e-02 4.7e-04 1.2e-02

Tb-160 1.9e+01 4.7e-01 1.2e-02 8.8e+01 3.8e+00 9.2e-01 1.4e-02 3.2e-01

Tm-170 3.4e-02 9.1e-04 3.0e-05 2.1e-01 6.7e-03 1.8e-03 3.4e-05 7.6e-04

Tm-171 2.3e-03 1.0e-04 3.1e-06 1.7e-02 4.5e-04 2.0e-04 3.4e-06 6.1e-05

Ta-182 2.3e+01 5.7e-01 2.6e-02 1.1e+02 4.6e+00 1.1e+00 2.9e-02 3.8e-01

W-181 1.6e-01 1.4e-03 2.9e-04 9.4e-01 3.1e-02 2.7e-03 3.3e-04 3.3e-03

W-185 2.0e-03 7.8e-05 2.1e-06 9.8e-03 4.0e-04 1.5e-04 2.3e-06 3.5e-05

Os-185 1.3e+01 2.0e-01 1.1e-02 5.3e+01 2.6e+00 3.8e-01 1.3e-02 1.9e-01

Ir-192 1.1e+01 1.9e-01 1.0e-02 5.8e+01 2.2e+00 3.6e-01 1.2e-02 2.1e-01

Tl-204 1.2e-02 2.0e-04 9.8e-05 7.8e-02 2.4e-03 3.9e-04 1.1e-04 2.8e-04

Pb-210 6.3e+00 2.4e-01 1.8e-02 1.2e+01 1.2e+00 4.6e-01 2.0e-02 4.3e-02

Bi-207 4.0e+01 5.5e-01 1.5e-01 1.6e+02 7.9e+00 1.1e+00 1.7e-01 5.6e-01

Po-210 2.5e+00 3.7e-02 3.0e-03 3.1e+00 4.9e-01 7.2e-02 3.3e-03 1.1e-02

Ra-226 3.5e+01 1.1e+00 2.7e-02 1.9e+02 6.9e+00 2.1e+00 3.0e-02 6.8e-01

Ra-228 1.9e+01 7.3e-01 1.6e-02 1.1e+02 3.7e+00 1.4e+00 1.8e-02 4.0e-01

Ac-227 2.8e+01 5.1e+00 7.7e-02 5.6e+01 5.4e+00 9.8e+00 8.5e-02 2.0e-01
Summary of Results Chapter 2

Table 2.2 Normalized effective doses to critical groups for all materials

Radionuclide

Mass-based (:Sv/y per Bq/g) Surficial (:Sv/y per Bq/cm2)

Steel Copper Aluminum Concrete Steel Copper Aluminum Concrete

NUREG-1640 2-8

Th-228 3.7e+01 3.3e+00 4.8e-02 1.7e+02 7.3e+00 6.3e+00 5.3e-02 6.0e-01

Th-229 3.2e+01 4.8e+00 1.0e-01 4.3e+01 6.4e+00 9.2e+00 1.1e-01 1.5e-01

Th-230 1.0e+01 5.5e-01 3.5e-02 7.3e+00 2.0e+00 1.1e+00 3.9e-02 2.6e-02

Th-232 1.1e+01 9.9e-01 3.7e-02 3.3e+01 2.1e+00 1.9e+00 4.1e-02 1.2e-01

Pa-231 3.3e+01 1.4e+00 1.1e-01 2.6e+01 6.6e+00 2.8e+00 1.3e-01 9.4e-02

U-232 1.4e+01 2.0e+00 3.2e-02 2.9e+01 2.7e+00 3.9e+00 3.5e-02 1.0e-01

U-233 5.9e+00 5.2e-01 7.6e-03 2.0e+01 1.2e+00 1.0e+00 8.4e-03 6.9e-02

U-234 4.2e+00 5.1e-01 7.4e-03 1.5e+01 8.1e-01 9.9e-01 8.2e-03 5.2e-02

U-235 5.1e+00 5.1e-01 8.4e-03 1.7e+01 9.9e-01 9.9e-01 9.3e-03 6.0e-02

U-236 3.8e+00 4.7e-01 6.9e-03 1.4e+01 7.5e-01 9.1e-01 7.7e-03 4.8e-02

U-238 3.9e+00 4.4e-01 6.7e-03 1.4e+01 7.7e-01 8.5e-01 7.5e-03 4.9e-02

Np-237 2.9e+01 1.2e+00 2.1e-02 9.9e+01 5.8e+00 2.4e+00 2.3e-02 3.5e-01

Pu-236 4.5e+00 6.3e-01 1.5e-02 3.2e+00 9.0e-01 1.2e+00 1.7e-02 1.2e-02

Pu-238 1.1e+01 8.5e-01 3.7e-02 7.9e+00 2.2e+00 1.7e+00 4.2e-02 2.8e-02

Pu-239 1.2e+01 6.5e-01 4.1e-02 8.5e+00 2.4e+00 1.3e+00 4.6e-02 3.0e-02

Pu-240 1.2e+01 6.5e-01 4.1e-02 8.5e+00 2.4e+00 1.3e+00 4.6e-02 3.0e-02

Pu-241 2.2e-01 9.4e-03 7.4e-04 1.6e-01 4.3e-02 1.8e-02 8.2e-04 5.6e-04

Pu-242 1.1e+01 6.1e-01 3.8e-02 8.2e+00 2.2e+00 1.2e+00 4.3e-02 2.9e-02

Pu-244 1.7e+01 7.5e-01 4.2e-02 3.9e+01 3.4e+00 1.5e+00 4.7e-02 1.4e-01

Am-241 1.1e+01 2.1e+00 3.4e-02 7.5e+00 2.1e+00 4.0e+00 3.8e-02 2.7e-02

Am-242m 1.1e+01 2.1e+00 3.4e-02 8.0e+00 2.1e+00 4.1e+00 3.8e-02 2.8e-02

Am-243 1.2e+01 2.1e+00 3.6e-02 2.0e+01 2.3e+00 4.1e+00 4.0e-02 7.1e-02

Cm-242 1.3e+00 2.5e-01 3.8e-03 7.2e-01 2.5e-01 4.9e-01 4.3e-03 2.6e-03

Cm-243 8.6e+00 1.6e+00 2.6e-02 1.3e+01 1.7e+00 3.0e+00 2.9e-02 4.8e-02

Cm-244 6.6e+00 1.3e+00 2.2e-02 4.3e+00 1.3e+00 2.5e+00 2.4e-02 1.5e-02

Cm-245 1.1e+01 2.1e+00 3.6e-02 1.2e+01 2.2e+00 4.0e+00 4.0e-02 4.4e-02

Cm-246 1.1e+01 2.1e+00 3.5e-02 7.1e+00 2.1e+00 4.0e+00 3.9e-02 2.5e-02

Cm-247 1.4e+01 2.0e+00 3.5e-02 3.4e+01 2.8e+00 4.0e+00 3.9e-02 1.2e-01

Cm-248 3.8e+01 7.2e+00 1.2e-01 2.6e+01 7.4e+00 1.4e+01 1.4e-01 9.1e-02

Bk-249 4.3e-02 7.7e-03 1.3e-04 3.1e-02 8.4e-03 1.5e-02 1.5e-04 1.1e-04

Cf-248 2.2e+00 4.4e-01 6.8e-03 1.3e+00 4.4e-01 8.6e-01 7.6e-03 4.8e-03

Cf-249 2.2e+01 3.6e+00 6.1e-02 3.9e+01 4.3e+00 6.9e+00 6.8e-02 1.4e-01

Cf-250 8.6e+00 1.7e+00 2.8e-02 5.7e+00 1.7e+00 3.2e+00 3.1e-02 2.0e-02

Cf-251 1.9e+01 3.5e+00 5.9e-02 1.9e+01 3.7e+00 6.8e+00 6.6e-02 6.8e-02

Cf-252 5.0e+00 9.7e-01 1.5e-02 3.3e+00 9.8e-01 1.9e+00 1.7e-02 1.2e-02

Cf-254 3.2e+02 8.7e+00 2.2e-01 1.4e+03 6.2e+01 1.7e+01 2.4e-01 4.9e+00

Es-254 1.9e+01 8.9e-01 1.8e-02 8.6e+01 3.8e+00 1.7e+00 2.0e-02 3.1e-01

Note: To convert these values to conventional units (mrem/y per pCi/g or mrem/y per pCi/cm2

), multiply by 0.0037
Chapter 3 Recycling and Disposal of Steel Scrap

1

 Throughout this report, the terms “NRC-licensed facility”, “licensed facility”, “nuclear facility,” and “licensee,”

unless otherwise qualified, refer to NRC- or Agreement State-licensed facilities. 

2

 As will be described later in this chapter, the major constituent of the ferrous metal scrap from NRC-licensed

facilities consists of carbon steel. In the remainder of this report, the term “steel scrap,” unless otherwise qualified, refers

to the various types of ferrous metal scrap.

3-1 NUREG-1640

Assessments have been performed of the potential radiation doses to individuals from the recycling or

disposal of iron and steel scrap that could be cleared from nuclear facilities. The assessment

addresses 37 scenarios that depict exposures resulting from the handling and processing of cleared

scrap and the products of melting and refining this scrap at steel mills and foundries, emission of

airborne effluents from these facilities, transportation of scrap and furnace products, the use of these

products, the landfill disposal of cleared scrap and furnace by-products, and the infiltration of well water

by leachate from landfills and storage piles containing cleared scrap or furnace by-products. The

analysis utilizes data on ferrous metal recycling, as currently practiced in the United States, and on

contemporary U.S. work practices and living habits.

The mean doses to the groups of exposed individuals characterized by 30 of these scenarios are

ranked to determine the critical groups for each radionuclide. Seven scenarios—describing exposures

to iron and steel products produced from the single furnace heat during one year that contains the

maximum fraction of cleared scrap—are not included in the ranking. 

The critical group for the largest number of radionuclides, accounting for over one-third of the 115

radionuclides in the analysis, consists of workers processing scrap at a scrap yard. 

Mean values of mass-based normalized EDEs to critical groups range from a high of 330 :Sv/y per

Bq/g (1.2 mrem/y per pCi/g) from Cf-254 to a low of 3.7e-4 :Sv/y per Bq/g (1.4e-6 mrem/y per pCi/g)

from S-35. The corresponding surficial EDEs are 65 and 7.4e-5 :Sv/y per Bq/cm2

, respectively. The

critical groups for both nuclides are the scrap yard workers. Mean values of mass-based normalized

effective doses range from a high of 330 :Sv/y per Bq/g (1.2 mrem/y per pCi/g) from I-129 to a low of

3.7e-4 :Sv/y per Bq/g (1.4e-6 mrem/y per pCi/g) from Ni-63. The corresponding surficial effective

doses are 64 and 7.3e-5 :Sv/y per Bq/cm2

, respectively. The critical group for I-129 is the individuals

drinking water from wells down gradient from a pile of steel slag, while that for Ni-63 is the scrap yard

workers.

3 RECYCLING AND DISPOSAL OF STEEL SCRAP

This chapter describes the radiological assessment of the recycling and disposal of iron and steel

scrap that could be cleared from NRC- or Agreement State-licensed facilities.1

 The model

created for this analysis is based on some of the steps that would most likely be involved in

recycling such scrap into consumer or industrial products, or in disposing of this scrap in an

industrial or municipal landfill. 

3.1 Introduction to Analysis

The assessment of the potential doses from cleared ferrous metal scrap2 consists of two main

parts. The first step is characterizing the flow of cleared scrap through the normal recycling

process, beginning with the generation of scrap, through melting and refining, manufacturing,

and product use, as well as disposal as an alternative to recycling. This enables the calculation
Recycling and Disposal of Steel Scrap Chapter 3

NUREG-1640 3-2

of concentrations of the various radionuclides in the products and by-products of the melting and

refining of steel scrap, normalized to an initial unit specific activity (Bq/g) or unit areal activity

concentration (Bq/cm2

). 

The second step is the development and analysis of exposure scenarios. The general approach to

the development of exposure scenarios is discussed in Section 1.2. The implementation of this

approach in the assessment of cleared steel scrap is described in the following sections.

3.1.1 Approach to Scenario Development

A number of previous assessments have been conducted to quantify the potential radiation

exposures of individual members of the public to the recycling of residually radioactive

materials. In general, these assessments have been based on the formulation and evaluation of

fairly specific scenarios that describe hypothetical situations in which individuals might be

exposed to residual radioactivity of reused or recycled materials. In order to be comprehensive,

this approach requires identifying the entire range of potential scenarios and using professional

judgment to select a final set for detailed analysis.

A review of the literature on radiological assessment indicates that there are two general

approaches to scenario-based assessments. The specific approach attempts to model, as

accurately as possible, the actual physical circumstances surrounding a selected set of very

detailed scenarios. Among the assessments addressing recycling of radioactive materials, this

approach is exemplified by the work of O'Donnell et al. (1978) in which an iron frying pan was

used as the reference consumer product. The analysis included calculations based on extensive

details of frying pan manufacture and use.

The specific approach has a number of limitations. First, it restricts the number of scenarios that

can be treated to those for which extensive, detailed descriptions can be formulated. Second, it

is open to the criticism that the chosen scenarios are too limited because they do not specifically

represent other situations of interest. Third, many separate parameters are required to describe

the scenarios. Finally, the data quality requirements for assigned values to these parameters

make serious demands on the analytical resources available to this study. Each parameter must

be researched, documented, and subjected to quality assurance procedures.

In contrast, a generic approach uses broadly defined scenarios that can represent a wide range of

possible exposure circumstances and does not attempt to model the details of any specific, realworld situation. Several recent studies illustrate the main features of this approach. Charles and

Smith (1992), for example, modeled a wide range of consumer products using a generic

geometry factor based on a cylinder of specified height, diameter, and thickness, without

attempting to mimic the manufacture and use of actual objects. Deckert et al. (1992) evaluated

two generic geometries—one defined as "a 1-kg object," the other as "a 1000-kg" object—to

represent different categories of consumer products.

The generic approach addresses some of the limitations of the specific scenario approach. By

representing a range of situations, carefully chosen generic scenarios can address any situation of
Chapter 3 Recycling and Disposal of Steel Scrap

3-3 NUREG-1640

interest that falls into that generic category. Furthermore, the number of detailed parameters can

be minimized, along with the effort required to derive and defend the value assigned to each

parameter. 

The approach taken in this analysis is a combination of the specific and generic approaches. A

number of specific scenarios have been modeled, as realistically as available data allow. In

addition, several generic scenarios have been modeled to represent a range of potential exposure

situations.

3.1.2 Scenarios Characterizing the Recycling and Disposal of Cleared Steel Scrap

A large number of potential exposure scenarios for the recycling and disposal of steel scrap

could be postulated. The design bases set for this study require that the scenarios be

comprehensive, appropriate, and practical. Comprehensive means that the scenarios have to

address the radiation exposures of individual members of potential critical groups. The scenarios

have to be appropriate to actual practices in the recycling and disposal of steel scrap and to

conditions of product use. Finally, the number of scenarios has to be practical, in that a

manageable number of scenarios would encompass the radiation exposures of the critical groups. 

The situations that could result in higher doses, but that have a low probability of occurrence, or

that postulate exposures of a small number of individuals, are excluded. The basis of exclusion

is that a key design objective of the analysis is to evaluate the likely radiation exposure of the

members of each critical group. Unlikely situations, or those that expose at most a handful of

individuals, do not meet this criterion. 

The approach to the present analysis is similar in some respects to that taken by Charles and

Smith (1992), who evaluated the feasibility of different options for managing large volumes of

very low-level radioactive waste. The management options included scenarios similar to those

selected for the present study, including clearance followed by recycling and/or disposal of scrap

metal, slag, and dust in landfills. The exposure scenarios used in their analysis were derived by

adopting the various management options. The generic nature of their exposure scenarios is

similar to that of some of the scenarios in the present analysis. A summary of scenarios used in

previous studies is presented in Table 3.1.

The scenarios listed in Table 3.1 fall into two broad categories: the individuals who are exposed

in the course of their occupation—“work-related” scenarios—and persons whose exposures are

not related to their occupations—“non-work-related” scenarios.
Recycling and Disposal of Steel Scrap Chapter 3

3

 Scrap and products and by-products of steel mills and foundries can also be shipped by rail or waterway.

4

 Ray Turner, The David J. Joseph Company, private communication with Robert Anigstein, SC&A, Inc., March,

2001. 

NUREG-1640 3-4

3.2 Flow of Steel Scrap

This section presents an overview of the recycling of steel scrap in the United States. Its purpose

is: (1) to serve as an information source for the radiological assessment, and (2) to present a

context for those aspects of the recycling and disposal of steel scrap that are addressed by this

assessment. It thus includes some data which are not directly utilized in our study.

Table 3.1 Scenarios discussed in previous studies

Work-related Non-work-related

& Decontamination and dismantling of concrete and

steel structures and handling scrap generated

during the process

& Transport of scrap to recycling or disposal facility

& Exposure to scrap piles

& Repair of contaminated machinery

& Operation of melter and subsequent processing

& Building renovation or demolition

& Landfill disposal (operation of facility or waste

fires)

& Reuse of large concrete masses (building

renovation)

& Reuse of contaminated slag in concrete

manufacture, production/manufacture of end

products

& Use of end products (i.e. frying pan, steel

furniture, automobile, steel reinforcement in

houses, large and small objects)

& Melting and refining process (airborne effluents)

& Slag in roadbeds, foundations of houses, use of

contaminated slag in concrete

& Landfill and sanitary disposal of waste products

or contaminated scrap (leachate, inadvertent

intrusion)

& Incineration of contaminated scrap

& Building occupancy by members of the public

& Drinking water that contains radionuclides

leached from surface soils

& Residential (contaminated soil)

& Shallow land disposal

& Reuse of large concrete masses (building

occupancy)

Figure 3.1 presents a schematic diagram of the flow of steel scrap, as characterized in the present

analysis. This diagram, which is a simplified idealization of the actual process, depicts the

sequence of steps which are represented by the exposure scenarios. Intermediate steps, not

represented by exposure scenarios, are indicated by dashed lines or boxes. Other steps and

processes are discussed in the following sections of this chapter.

The process begins with the release of cleared scrap from an NRC-licensed facility. It is

assumed that the scrap is shipped by truck3

 to a scrap yard operated by a scrap metal dealer. The

processing performed by this dealer, which can vary with the grade (i.e., type or composition) of

scrap, includes shearing or torch-cutting the metal to size, briquetting or crushing thin and

lightweight materials (e.g., turnings and borings), and baling.4

 The scrap dealer then ships the
Chapter 3 Recycling and Disposal of Steel Scrap

5

 The generic term “melt shop” is used throughout this chapter to refer to any facility where scrap metal is melted

and refined into finished or semi-finished iron or steel products.

6

 Another alternative scenario is the processing of scrap at the nuclear facility. Such processing would most likely

be performed by radiation workers whose occupational exposures are controlled under current regulations. This scenario

is therefore outside the scope of the present study, which is limited to assessing the radiation exposures of members of the

public.

3-5 NUREG-1640

Figure 3.1 Flow of steel scrap

processed scrap to a melt shop,5 where it may be stored for a time or immediately charged to a

furnace.

Alternatively, the licensee or demolition contractor may elect to dispose of the scrap in an

industrial or municipal solid waste (MSW) landfill.6

The U.S. iron and steel industry comprises three main types of facilities that consume steel

scrap: basic oxygen furnaces (BOFs), which are components of integrated steel mills; electric
Recycling and Disposal of Steel Scrap Chapter 3

7

 Some small induction furnaces do not use an APCD, resulting in a total release of the offgas to the atmosphere.

8

 RCRA is the abbreviation for the Resource Conservation and Recovery Act, which regulates the land disposal of

hazardous wastes.

9

 Processing of EAF dust is not shown in Figure 3.1. 

NUREG-1640 3-6

arc furnaces (EAFs) used to make steel; and cupola furnaces, induction furnaces, and EAFs at

iron and steel foundries. These facilities are discussed in greater detail later in this chapter.

During melting, the furnace charge separates into three different process streams: offgas, slag,

and metal. Each of the process streams undergoes different treatment, use, and final disposal. 

The offgas includes gases, vapors, or particulates that evolve from the furnace. The vapors may

form particulates when cooled. Most of the particulates are collected in baghouse filters or other

air pollution control devices (APCDs). The gaseous effluents, as well as a fraction of the

particulates that escape the APCD, are dispersed into the atmosphere.7 Most basic oxygen

furnace (BOF) dust and sludge is either landfilled directly or landfilled after recovery of metal

values. Small amounts of the dust are recycled directly at the integrated steel mill and small

amounts are used in cement. 

Electric arc furnace (EAF) baghouse dust is a RCRA-listed8 waste (K061), containing potentially

hazardous elements such as lead, cadmium, and chromium. The disposal of this material must

therefore conform to applicable EPA regulations. The dust could be disposed of directly in a

RCRA Subpart C (hazardous waste) landfill; the dust could be stabilized by an EPA-approved

process and disposed of as delisted waste in an industrial landfill (either on site or at a regional

location); the dust could be processed for recovery of valuable metals; or the dust could be

incorporated into fertilizer. At the time this issue was investigated, the two most common

treatment and disposal methods in use were: (1) immobilization treatment, followed by disposal,

and (2) high-temperature metals recovery. Processing of EAF dust at a generic disposal or

treatment facility is addressed in the present analysis, as is landfill disposal following

immobilization.9 The EAF dust is typically transported in trucks operated by brokers licensed to

handle hazardous waste. At either type of facility, the dust is typically unloaded in an enclosed

building, where it is immediately placed in a bin and moistened with water for dust control.

Slag is a nonmetallic product resulting from the interaction of flux and impurities in the molten

metal. Because slag is lighter than iron, it will float on top of the melt. After slag is removed

from the furnace and cooled, it is stored in piles outdoors at the melt shop until it is either used

by the mill or transported to a slag processor. Since the slag contains compounds such as

calcium oxide, hydration of up to 10% can occur, limiting the use of steel slags, as compared to

blast furnace slags. Steel slags can be used in applications such as railroad ballast or unconfined

highway base and shoulders, where expansion from hydration will not pose a problem. Some

BOF slag is used as an additive in cement kilns (American Iron and Steel Institute, as cited in

Florida Steel Homes, Inc. 1998). Typically, steel slags are stored outdoors for six months or

more to reduce the free lime content to levels where slag stability is acceptable. This also
Chapter 3 Recycling and Disposal of Steel Scrap

10 See Footnote 3 on page 3-4.

11 Throughout this chapter, metric tons (tonnes) are abbreviated as “t.” The term “tons” refers to short tons (1 ton =

0.9072 t)

3-7 NUREG-1640

provides adequate time for dicalcium silicate to expand to stable levels (Kalyoncu 2002). 

Alternatively, the slag is transported by truck10 for disposal in a landfill. 

The iron or steel produced by a melt shop is used in a virtually endless variety of products. The

present analysis models exposures to three generic products as well as five specific products

made from iron or steel.

3.2.1 Sources of Cleared Steel Scrap 

The radiological assessment described in this chapter is limited to scrap steel cleared from NRClicensed facilities. These include commercial nuclear power plants, test and research reactors,

other fuel cycle facilities, and by-product material licensees. By far the largest single source of

steel scrap cleared from NRC-licensed facilities would be the dismantling of a commercial

nuclear power plant (see Section A.7). The scrap cleared during such dismantlement is therefore

used as the source term for the present analysis. All commercial nuclear power plants currently

licensed to operate in the United States employ light-water reactors which are of two types: 

boiling water reactors (BWRs) and pressurized water reactors (PWRs). Separate estimates of the

masses of steel scrap that would be cleared during dismantlement have been made for the two

types of power plants:

• BWR . . . . . . . . . . . . . . . . 14,657 – 19,374 t11

• PWR . . . . . . . . . . . . . . . . 19,754 – 23,592 t 

A more detailed discussion of the estimated steel scrap from the Reference BWR is presented in

Section A.2.3.5. The corresponding data on the Reference PWR is discussed in Section A.2.4.2. 

Of the 104 nuclear power reactors currently licensed to operate in the United States, 35 are

BWRs and 69 PWRs (NRC 2000). It is therefore assumed that there is a 33.7% probability that

a reactor undergoing dismantlement at a particular time and place would be a BWR and a 66.3%

probability that it would be a PWR. 

According to a decommissioning analysis performed for the NRC by Pacific Northwest

Laboratory (Konzek et al. 1995), the dismantlement of a PWR would take 1.7 years. Based on

this information, we assume that the scrap generated during the dismantlement of either a BWR

or PWR nuclear power station would be cleared and released at a uniform rate over a 1.7-year

period.

As was discussed in Section 1.1, the first step in the assessment is to calculate mass-based

normalized doses. For the purpose of that calculation, we assume that all cleared scrap will be
Recycling and Disposal of Steel Scrap Chapter 3

12 For example, about 74 Mt of ferrous scrap were consumed in 2000 and 5.8 Mt were exported (Fenton 2002). 

13 The steel scrap recycle rate for 2000 has been estimated to be 64% (Fenton 2002). 

14 Direct reduced iron is produced by reacting lumps or pellets of iron oxide in a shaft furnace with natural gas to

produce metallic iron. Unlike in the blast furnace, reduction occurs in the solid state.

NUREG-1640 3-8

uniformly contaminated by one of the 115 radionuclides that are addressed in the present

analysis. Long-lived nuclides with short-lived progeny (i.e., those with half-lives of less than six

months) are assumed to be in secular equilibrium with these progenies at the time of clearance. 

(Radioactive decay chains and progeny ingrowth are discussed in detail in Appendix E.)

3.2.1.1 Secondary Recycling

The present analysis does not explicitly address secondary recycling: iron and steel products

made from cleared scrap that are in turn recycled at the end of their useful lives. Such secondary

recycling could, in theory, lead to a buildup of radioactivity in the metal pool. However, as

discussed below, such buildup would not make a significant contribution to the doses to

individual members of the various critical groups, which is the objective of the present analysis.

• Many of the radionuclides that would remain in the finished iron or steel products following

melting and refining—especially the emitters of strong external radiation (i.e., -rays)—have

relatively short half-lives—approximately 5 years or less. Consequently, any buildup over a

period of years would be partially offset by radioactive decay.

• It is conceivable (as assumed in the present analysis) that all the ferrous scrap cleared from a

single licensed facility (e.g., a commercial nuclear power plant) would be consumed by a

single steel mill or foundry. However, the finished steel products made with the recycled

scrap would be distributed throughout the United States, as well as abroad. When these

products reach the end of their useful lives, they will, in many cases, be recycled in turn. 

Because of the wide dispersal of these products, the secondary recycling would be distributed

throughout the iron and steel industry, both here and abroad.

• Not all of the products made from cleared scrap would be recycled domestically, because: (1)

some of the products would be sold abroad, (2) some of the products would be discarded

rather than recycled, and (3) some of the scrap generated from the discarded products would

be exported.12

• The total amount of steel scrap that could be cleared by NRC-licensed facilities over the next

50 years is about 2.4 Mt; therefore, about 48 kt would be cleared in an average year (see

Section A.7). Let us assume that: (1) all this scrap is initially recycled and (2) a fraction13 of

the spent products made from this recycled scrap enters the U.S. pool of secondary ferrous

metals. Simultaneously, about 51 Mt of virgin metal, in the form of pig iron and direct

reduced iron (DRI),14 is produced each year. Eventually, through recycling, a similar
Chapter 3 Recycling and Disposal of Steel Scrap

3-9 NUREG-1640

fraction of this metal also enters the secondary metals pool. Thus, the 48 kt of cleared scrap

is offset by 51 Mt of virgin metal, a dilution of 1:1,000.

• The buildup from secondary recycling of products made from cleared scrap would thus

comprise at most 0.1% of the initial specific activity of this scrap—this assumes no

radioactive decay, steady state conditions, and an indefinitely long period of time to achieve

equilibrium (i.e., several times the average life of recyclable steel products). By comparison,

the average mixing of cleared scrap at a single iron- or steelmaking facility in the present

analysis is calculated to be approximately 6%. Consequently, even if radioactive decay were

neglected, secondary recycling could contribute, at some future time, an additional 1.6%

(0.1 ÷ 6 = 0.016) to the radionuclide concentration in finished products, as modeled by the

present analysis. Given the uncertainty in the other parameters, this would make an

insignificant contribution to the calculated doses to individual members of the potential

critical groups.

The potential long-term buildup of radioactivity in the steel pool would thus make no significant

impact to individual doses, and is therefore outside the scope of the present analysis. 

3.2.2 Recycling of Steel Scrap

Three significant sources of ferrous metals are used in the production of steel and cast iron: pig

iron, DRI, and scrap. Pig iron is produced in a blast furnace where the primary source of iron

units is iron ore supplemented with small amounts of scrap and DRI (Fenton 2002). Feedstock

to produce wrought steel products is melted either in an EAF, where the bulk of the furnace

charge is scrap, or in a BOF, where about one-fourth of the furnace charge is ferrous scrap and

the balance is pig iron. Cast iron and steel are produced in small EAFs, cupolas, or induction

furnaces, where the bulk of the furnace charge is scrap. 

A total of 74 Mt (8.2 × 107

 tons) of iron and steel scrap was consumed in the United States in

2000. Of this total, 15 Mt was consumed during the making of steel in BOFs, 43 Mt was

consumed in steelmaking in EAFs, and the balance was consumed in blast furnaces producing

pig iron and in furnaces producing iron and steel castings (Fenton 2002). 

There are three types of scrap metal used in the steelmaking industry: home, new, and old. 

Home scrap consists of unusable metal produced during the processing or fabrication of steel at

the mill into a suitable intermediate product. Even though home scrap is produced at the steel

mill or foundry, it is considered a secondary metal, in contrast to processed raw material—i.e.,

pig iron. New scrap (or prompt scrap) is produced during manufacture of end products. New

scrap is high-grade metal with very few impurities. Old scrap includes obsolete, worn-out or

broken products that have been used by consumers or by industry. Approximately 44% of the

scrap recycled in 2000 was obsolete or old scrap (USGS 2001). Old scrap is usually lower

quality metal, and its chemical composition may not be well known. Scrap metal cleared from a

licensed facility that is to be recycled would enter the pool of old scrap. 
Recycling and Disposal of Steel Scrap Chapter 3

15 The scrap consumed was comprised of 45 Mt of purchased scrap and 14 Mt of home scrap. 

NUREG-1640 3-10

Scrap is not completely interchangeable among the various types of melting furnaces. BOFs

tend to use heavier grades of scrap (e.g., shredded scrap is typically not used), tend to use more

prompt scrap, and tend to use higher grades of purchased scrap. However, the types of scrap that

would be generated by the dismantling of nuclear power plants (primarily rebar, structural steel,

and pipe hangers) would be reasonably interchangeable and are so treated in this analysis.

3.2.3 Iron- and Steelmaking

Figure 3.2 shows some of the steps in the melting and refining of steel scrap. It is presented for

purposes of illustration, and does not represent all of the steps in the flow of steel scrap that is

modeled in the present analysis. Foundry operations are not shown in this figure, but they would

be similar to the BOF and EAF illustrated. 

Steel is produced either at integrated steel mills where molten iron (hot metal), generated in a

blast furnace by the reduction of iron ore, is refined into steel in a BOF, or at non-integrated

mills that use EAFs to melt furnace charges largely comprised of scrap.

Together, integrated and non-integrated mills consumed a total of approximately 59 Mt of steel

scrap,15 and produced a total of 102 Mt of raw steel in 2000 (Fenton 2002, Fenton n/d). This

included 92.5 Mt of carbon steel, 2.19 Mt of stainless steel and 7.5 Mt of other alloy steel. Net

shipments of steel mill products were 98.9 Mt. In addition, iron and steel foundries consumed

15.2 Mt of scrap and shipped 10.6 Mt of iron and steel castings.

3.2.3.1 Integrated Steel Mills

Integrated steel mills produce pig iron in blast furnaces and refine this pig iron to finished steel

in basic oxygen furnaces. The basic oxygen process for steelmaking involves blowing oxygen

into the molten steel bath, contained in a refractory-lined vessel, to decrease the amount of

oxidizable impurities to desired levels. In 2000, BOFs were used by integrated steel makers to

produce 54 Mt of steel in the United States. At that time the integrated steel industry comprised

13 companies operating in 19 locations (Fenton n/d). An earlier survey of BOFs (“1991 Guide

to North American Steel Industry” 1991) listed 59 furnaces operated by 16 companies in 26

locations in the United States, while in a more recent report, EPA (2001a) lists 50 BOFs

operating at 20 locations. All integrated steel producers operate blast furnaces, which supply

about three-fourths of the total metal requirement for the BOFs, and several operate sinter plants,

which process waste and by-product materials for recycling into the blast furnaces. A listing of

current integrated steel makers and their capabilities is included in Table 3.2.
Chapter 3 Recycling and Disposal of Steel Scrap

3-11 NUREG-1640

Figure 3.2 Examples of steelmaking processes
Recycling and Disposal of Steel Scrap Chapter 3

16 Twenty-six percent to 29% of the charge at Bethlehem Steel’s Sparrows Point Plant is scrap and from 38% to

48% of the total scrap charge is home scrap (Timothy W. Miller, Supervisor, Coke, Iron and Steelmaking Research,

Bethlehem Steel Corporation, private communication with Kathleen Behling, SC&A, Inc., September 26, 2001). Factors

affecting the variability in these parameters include product demand, product mix, and costs of scrap and blast furnace

hot metal. Sparrows Point is believed to be fairly typical of the integrated steel industry.

NUREG-1640 3-12

Table 3.2 Integrated iron and steel mills

Company Location BOF Shops Blast

Furnaces

Sinter

Plants

Capacitya

Vessels Shops tons/y kt/y

Acme Steel Riverdale, IL 2 1 1 1,290,000 1,170

AK Steel Ashland, KY 2 1 1 2,168,000 1,967

AK Steel Middletown, OH 2 1 1 1 2,716,000 2,464

Bethlehem Steel Burns Harbor, IN 3 1 2 1 5,354,000 4,857

Bethlehem Steel Sparrows Point, MD 2 1 1 1 4,000,000 3,629

Geneva Steel Orem, UT 2 1 3 1 2,500,000 2,268

Gulf States Steel Gadsden, AL 2 1 1 1,300,000 1,179

Inland Steel East Chicago, IN 4 2 3 1 5,240,000 4,754

LTV Steel Cleveland, OH 4 2 3 7,720,000 7,004

LTV Steel East Chicago, IN 2 1 2 1 4,161,000 3,775

National Steel Granite City, IL 2 1 2 2,575,000 2,336

National Steel Ecorse, MI 2 1 3 4,100,000 3,720

Rouge Steel Dearborn, MI 2 1 2 3,309,000 3,002

USX Braddock, PA 2 1 2 2,760,000 2,504

USX Fairfield, AL 3 1 1 2,200,000 1,996

USX Gary, IN 6 2 4 1 6,927,000 6,284

USS/Kobe Steel Lorain, OH 2 1 2 2,600,000 2,359

WCI Steel Warren, OH 2 1 1 1,728,000 1,568

Youngstown, OH 1 — —

Weirton Steel Weirton, WV 2 1 2 3,200,000 2,903

Wheeling-Pittsburgh Steel Mingo Junction, OH 2 1 2 2,600,000 2,359

Follansbee, WV 1 — —

Total 50 23 39 9 68,448,000 62,096

Source: EPA 2001a

a

 Production capacity (tons of steel poured per year)

At a typical BOF, a 220-t heat is poured every 45 minutes. BOF shops usually obtain 20% to

35% of the metal charge from scrap (Fruehan 1998).16 Based on the nominal heat size and the

reported annual furnace capacity in the 1991 survey, the average number of heats per year was

calculated to be 5,609 with a range of 3,000 to 7,500. The average heat size was calculated to be

215 tons with a range from 80 to 360 tons. Using annual capacities from the more recent EPA

report, the average number of heats per year was estimated to be 6,023 with a range from 3,667

to 9,955 (EPA 2001a).
Chapter 3 Recycling and Disposal of Steel Scrap

17 Timothy W. Miller, Supervisor, Coke, Iron and Steelmaking Research, Bethlehem Steel Corporation, private

communication with Kathleen Behling, SC&A, Inc., September 6, 2001. 

3-13 NUREG-1640

A representative BOF material balance shows that a heat consisting of 878 kg of hot metal, 202

kg of scrap, and 17 kg of iron ore will produce 1,000 kg of steel (Fruehan 1998, Table 9.8). One

source estimates that about 24% of the scrap charge is internally generated scrap: home scrap

(scrap from current operations that recirculates within the melt shop) plus obsolete scrap from

on-site dismantling (SRI 2001). Fenton (2002) quotes 24% as the average fraction of scrap in

the furnace charge. If we assume that the small amount of iron ore in the charge is FeO, about

91% of the metal charged would be recovered as raw steel. 

During the oxygen blow (used to adjust the melt chemistry), elements such as Cu, Mo, Sn, and

Ni cannot be oxidized and are thus not removed from the metal. Elements such as Al, Si, and Zr

are fully oxidized and become incorporated in the slag. Elements such as Mn, P, and Cr are

distributed between the metal and the slag. Zinc and Pb are mostly removed from the bath as

vapor (Fruehan 1998). 

After tapping the molten metal, the slag remaining in the furnace is either dumped into a slag pot

or is splashed on the walls of the furnace to extend liner life (Fruehan 1998). This slag

splashing, which is practiced by 40 to 50% of the North American BOF melt shops, involves 5%

to 20% of the slag generated during a heat. However, this temporary coating lasts only one to

two heats, so the net effect is that all the slag is removed from the furnace after a few successive

heats.17

BOF slag is composed of calcium silicates and ferrites combined with fused oxides of iron

aluminum, manganese, calcium, and magnesium. A typical slag composition (in wt %),

assuming all compounds are present as oxides, is given by Fruehan (1998):

CaO . . . . . . . . . . . . . . . . . . . . . . . . . . . 47.9

SiO2 ........................... 12.0

MgO . . . . . . . . . . . . . . . . . . . . . . . . . . . 6.30

FeO . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26.4

MnO . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.00

P2O5 ........................... 1.10

Al2O3 .......................... 1.30

Slag is removed from the furnace, cooled, and processed to recover the high metallic portions

(which are rich in iron and manganese). These are used as a source of metallics in sinter plants

or as a flux in blast furnaces. The remaining non-ferrous fraction is crushed and sized for reuse

within the steel mill, sold as a by-product, or disposed of in a landfill (AISI 1998, Chapter 4). 

Although some slag may be recycled into the steelmaking operation, internal recycling has been

decreasing as the demand for higher quality steel has increased. A steel industry source has

estimated that 30% to 40% of the slag is recycled back to the sinter plant and the blast furnace,

the balance being landfilled.17 At some shops, 100% of the slag is landfilled.
Recycling and Disposal of Steel Scrap Chapter 3

18 Based on more recent measurements from three melt shops, EPA (2001a) has replaced this dust release value

with a figure of 17.5 g/t or 99.9% removal.

NUREG-1640 3-14

The slag output of a BOF ranges from 100 to 440 lb per ton of steel (50 to 220 kg/t), averaging

about 240 lb per ton (120 kg/t) (AISI 1998, Chapter 4). The amount of slag varies with the

amount of silicon in the hot metal from the blast furnace which feeds the BOF.17 The average

value of 240 lb per ton is in close agreement with the typical value of 200 lb per ton (100 kg/t)

quoted by Fruehan (1998, Table 9.8), and is identical to the value quoted elsewhere in that

reference (Section 9.7.4.1). Since BOFs produced 54 Mt in 2000, the total amount of slag

generated in that year is estimated to be about 6.5 Mt ( 54 Mt steel × 0.12 = 6.5 Mt). 

The fumes that are generated when oxygen is added to a BOF are captured by the primary

exhaust hood and cleaned by high pressure venturi scrubbers or electrostatic precipitators. The

fumes generated during melting, tapping (pouring molten steel), and slagging (decanting slag)

are captured by local or canopy hoods and transported via a duct system to a baghouse. A

limited number of BOF shops use electrostatic precipitators (ESP), which produce a “filter cake”

containing 7% to 10% moisture. Most shops use venturi scrubbers, which produce sludges

containing 40% to 90% moisture. From the venturi scrubbers, the fine particulates entrained in

the waste water stream are sent to thickener/flocculation tanks for settling and solids removal. 

The underflow slurry from the thickener can be dewatered by mechanical filtration (AISI 1998,

Chapter 4). 

Trace hazardous air pollutants found in the BOF offgas include Cd, Cr, Ni, Pb, Mn, and Zn

(Fruehan 1998). A slightly different list was quoted by EPA (2001b) in the proposed NESHAP

for integrated iron- and steelmaking. EPA states that hazardous air pollutants emitted as

particulate matter include Sb, As, Be, Cd, Cr, Co, Hg, Ni, Mn, Pb and Se, with Mn and Pb being

the primary elements of concern. The compositions of fume from a top-blown BOF and bottomblown BOF (Q-BOP) are listed in Table 3.3.

AISI (1998, Chapter 4) estimates that between 8 and 62 lb of dust and sludge are produced per

ton of raw steel (4 – 31 kg/t), with 36 lb per ton (18 kg/t) being the average. Fruehan notes that

fugitive emissions from a well-designed filtering system in a BOF shop are 0.158 lb/ton (79 g/t)

of steel, which implies 99.4% removal. Jeffery and Vay (1986) cite a value of 45 g/t of steel for

a top-blown BOF controlled by an open hood vented to a scrubber (99.7% removal based on

uncontrolled emissions of 14.25 kg/t of steel) and 65 g/t for an open hood vented to an ESP

(99.5% removal). Atmospheric releases are even lower when controlled by a closed hood vented

to a scrubber, being 3.4 g/t of steel (99.98% removal).18 These authors also cite a value of 28 g/t

of steel for a bottom-blown BOF (Q-BOP) controlled by a scrubber (99.8% removal).

Based on a 1988 survey, EPA concluded that 4% of the dust/sludge was recycled at the

integrated steel maker, 44% was disposed of, and 52% was sold or sent off site for further metal

recovery (AISI 1998, Chapter 4). Any metal recovered would become part of the home scrap or

prompt scrap sources of feed. Fruehan (1998, Section 9.3.5.2) describes the growing use of

waste oxide recycling to address environmental concerns associated with landfill disposal. 
Chapter 3 Recycling and Disposal of Steel Scrap

3-15 NUREG-1640

Waste oxide briquettes containing sludges, grit, and mill scale are being used as a coolant ore

substitute in some BOFs. As noted above, coolant ore constitutes only about 2% of the total

furnace charge. The waste oxides are collected, blended, dried, mixed with lime and binders,

and pressed into pillow-shaped briquettes. The briquettes are then cured to remove moisture. A

typical waste oxide briquette composition is 35 wt% sludge, 20 wt% grit, and 45 wt% mill scale. 

Successful exploitation of this technology could reduce the amount of material being landfilled. 

Fruehan (1998) states that small amounts of dust and sludge are recycled to the sinter plant for

metal recovery (this is consistent with AISI 1998, Chapter 4), and that small amounts are sold to

the cement industry. The balance is not accounted for by Fruehan, but is presumably landfilled. 

Limited recycling of dust and sludge is confirmed by AISI 2001 (p.63), where it is noted that

less than half the steelmaking dust and sludge is reused. 

Table 3.3 Analysis of top-blown BOF and Q-BOP fume

Element Concentration in gas (mg/m3

 at STP)

BOF (top-blown) Q-BOP

Aluminum MCa 0.43

Antimony 0.006 <0.001

Arsenic 0.05 <0.02

Barium >0.11 0.02

Bismuth >0.11 0.02

Cadmium 0.077 0.002

Calcium MC 64

Chromium 0.84 0.26

Copper 0.18 0.1

Iron >2.7 85.3

Lead >0.02 0.41

Magnesium >0.55 2.3

Manganese >0.11 3.8

Mercury 0.0008 >0.0031

Nickel 0.31 0.18

Phosphorus MC 0.53

Selenium 0.087 <0.033

Silicon >1.1 4.2

Strontium 0.016 <0.056

Sulfur >0.06 7.9

Zinc MC 0.14

Source: Felton et al. 2000

a

 MC = major component (concentration not available)

If the sludge is high in zinc (from melting galvanized steel scrap), it cannot be recycled to the

blast furnace. However, it can be recycled to the BOF. A steel industry source estimated that

some plants may recycle as much as 15% back to the BOF as coolant ore, but this type of sludge
Recycling and Disposal of Steel Scrap Chapter 3

19 Timothy W. Miller, Supervisor, Coke, Iron and Steelmaking Research, Bethlehem Steel Corporation, private

communication with Kathleen Behling, SC&A, Inc., September 26, 2001. 

NUREG-1640 3-16

recycling is practiced at only about one-fourth the integrated steel melt shops.19 Use of sludge as

a filler material is rare. 

Since the total amount of scrap in the BOF charge is limited to about 25%, a significant fraction

of which is home scrap, the concentrations of EPA-listed hazardous metals (i.e., lead, cadmium,

and chromium) in the dust are below regulatory limits. Therefore, BOF dust is not listed as a

hazardous waste (Arthur D. Little 1993). 

As indicated in Table 3.2, several of the integrated steel mills have associated sinter plants which

accumulate iron units from various process streams and consolidate these iron units with carbon

and flux into a form suitable for incorporation as part of the blast furnace feed. Since EPA

2001a, the source document for Table 3.2, was published, the WCI sinter plant has been shut

down (“WCI Idles Youngstown Sinter Plant” 2001) leaving only eight plants in operation in the

United States. BOF furnace dust and sludge is typically not one of the process streams used as a

feed source for the sinter plants due to the presence of zinc, which has a deleterious effect on

blast furnace operations (AISI 2001, p. 63). In 2000, 10.6 kt of sinter, accounting for about 15%

of total blast furnace feed, was consumed in producing pig iron (Fenton n/d). In assessing the

mass balance of raw and recycled materials entering the furnace, the sinter plays a role similar to

home scrap.

3.2.3.2 Non-Integrated Steel Mills

Non-integrated steel mills mostly employ EAFs and produce carbon steels, stainless steels, tool

steels, and other alloy steels. Carbon steel EAF shops are often referred to as mini-mills. AISI

(2001) notes: Once relegated to producing inexpensive concrete reinforcing bar, today minimills can produce over 80% of all steel products.

In 2000, the non-integrated steel producers used EAFs to produce 47% of total steel production

at 120 steelmaking plants (Fenton n/d). The same author estimates that 95.5% of the total EAF

production is from scrap (Fenton 2002). It is estimated that about 25% of this scrap is home

scrap (SRI 2001). Pig iron and DRI provide the balance of the iron units.

Penton Publishing has recently issued the “North American Mini-Mill/Market Mill EAF Census”

(2000) which focuses on furnaces used for melting high-volume carbon steel products. 

Specialty, alloy, tool, and stainless steel EAFs are not included. A number of nonoperating

furnaces are also excluded. The survey lists 94 furnaces, including the average heat size and raw

steel annual capacity of each. The number of heats per year can be calculated from this

information. For the total population of furnaces, the heats range from 1,538 to 11,765, with an

average of 5,634. The average heat size for melting carbon steel, based on the Penton census, is

108 tons, (98 t) with a range from 32 to 365 tons (29 – 331 t).
Chapter 3 Recycling and Disposal of Steel Scrap

20 It is appropriate to eliminate these furnaces because EAFs used for steel castings are included with iron and steel

foundries, while EAFs producing metal powders and superalloys require special feedstocks.

3-17 NUREG-1640

A more comprehensive survey of EAF furnaces is published each year by the Iron and Steel

Society (I&SS)—e.g., “EAF Roundup” 2001. The survey includes numerous facilities that are

not currently operating. The I&SS survey also includes EAFs used for making steel castings, as

well as specialty, alloy, tool, and stainless steels, and metal powders and superalloys. EAFs used

for these applications tend to be smaller and may operate fewer turns per week. Scrap charges

must be more selective to meet stringent and specialized heat chemistries. 

The I&SS survey includes more than 200 EAFs. If we eliminate from this population furnaces

used for producing metal powders, steel castings, and superalloys,20 178 furnaces remain,

including furnaces that are not operating or that produce various speciality steels (including

stainless steels). Of this total, sufficient data are available on 166 furnaces to calculate the

number of heats per year: the average value is 4,405, with a range of 500 to 10,800.

The average value of heats per year from the I&SS survey is about 20% lower than that

calculated from the Penton EAF Census. This is not surprising, since the I&SS survey includes a

large number of speciality steel melting furnaces that typically operate with lower capacity

factors. 

The average heat size, based on 178 furnaces, is 97 tons (88 t), with a range of 6 to 370 tons (5.4

– 336 t). The minimum heat size occurs at Champion Steel, a producer of “hard-to-find” grades

of tool and high speed steel, while the maximum is at Furnace #7 at Northwestern Steel and Wire

(currently in standby). 

During refining of the molten steel bath, P, S, Al, Zn, Mn, Cr, and C are typically removed. 

With the exception of carbon, removal is by partial transfer of these species to the slag phase as

oxides (Fruehan 1998). The partition ratio (slag:steel) for phosphorus typically ranges from 5 to

15, and for sulfur from 3 to 5. Manganese is commonly lowered to about 0.06% in the bath

(Fruehan 1998 ). Additional refining may be accomplished in the ladle to which the molten steel

from the EAF is transferred. Ladle refining vessels typically use electric arc reheating (AISI

2001). 

The fumes generated during the melt-down and refining period of an EAF are evacuated directly

off the furnace (direct shell evacuation) and transported via a duct system to the collection

system. The fumes produced during melting, tapping, and slagging are evacuated through a

fume collection hood on the roof of the building, then transported through a duct to the

collection system. The most efficient, cost-effective and typical collection system used to

control the EAF fume dust is the fabric filter baghouse system. 
Recycling and Disposal of Steel Scrap Chapter 3

21 There is some confusion in Fruehan 1998 about the measurement base. In Section 10.4.5 the values are quoted as

“9-18 kg (20-40 lbs) per ton of scrap melted,” while in Section 10.4.6.2 the values are quoted as “9-18 kg (20-40 lbs) per

ton of steel produced” (emphasis added).

22 Both values are cited by Jeffery and Vay (1986) for uncontrolled emissions from EAFs melting carbon steel.

23 Excludes data withheld to avoid disclosing company proprietary data.

24 Includes withheld data on “Other” furnaces.

NUREG-1640 3-18

Dust generation rates have been reported to range from 20 to 40 lb/ton of scrap melted (10 to 20

kg/t) (Fruehan 1998).21 This is also consistent with an average value of 1.5 t of dust per 100 t of

scrap melted cited by Anigstein et al. (2001). 

Metals known to volatilize as the scrap heats up include Zn, Pb, Cd, Na, Mn, and Fe. These

metals tend to form oxides following volatilization and report to the dust in that form. CaO

carryover from lime (added as slag former) also occurs (Fruehan 1998).

Jeffery and Vay (1986) cite a value of 21.5 g/t of carbon steel for atmospheric releases from an

EAF using direct shell evacuation plus charging hood vented to a common baghouse. 

Depending on whether uncontrolled emissions are 19 or 25 kg/t,22 the removal is 99.88% ([19 -

0.0215] ÷ 19 = 0.9988) or 99.91% ([25-0.0215] ÷ 25 = 0.9991).

3.2.3.3 Iron and Steel Foundries

Iron and steel required for castings are melted in a variety of furnaces, including small EAFs,

cupola furnaces, and electric induction furnaces. About 91.5% of the furnace charge in iron

foundries is scrap and the balance is mainly pig iron (Fenton 2002, Table 4). Iron and steel

foundries account for 20% of ferrous scrap consumption. 

Scrap consumption by manufacturers of steel castings and by iron foundries and miscellaneous

users in 2000 is summarized below (Fenton 2002, Table 4):

• Electric arc furnace . . . . . . . . . . . . . 7.4 Mt

• Cupola furnace ................. 7.4 Mt

• Other (including air furnaces)23 . . . . . . 2 kt

• Total24 ....................... 15.2 Mt

Of this total, 5.8 Mt, or 38%, was recirculating or home scrap (Fenton 2002, Table 2).

Iron castings are produced in a wide range of sizes. For example, Atchison Casting (2001)

reports that it produces parts ranging from a few pounds up to 70,000 pounds (> 32 t). In 1989,

about half of all iron castings were used by automotive and truck manufacturers (EPA 1995a,

Section 12.10).
Chapter 3 Recycling and Disposal of Steel Scrap

25 This excludes three furnaces with capacities of 0.13, 0.25, and 0.75 tons/h which are presumably prototypes

rather than production furnaces.

26 Jim Maysilles, Metals Group, Emission Standards Division, U.S. Environmental Protection Agency, Research

Triangle Park, NC, private communication with Kathleen Behling, SC&A, Inc., September 27, 2001.

3-19 NUREG-1640

Cupola Furnace Melting

The cupola is similar to a small blast furnace, where the iron ore in the charge is replaced by pig

iron and steel scrap. A 1998 EPA survey of iron and steel foundries lists furnaces with melt

rates ranging from 0.6 to 130 tons per hour (0.5 – 118 t/h)25 and an average melt rate of 27 tons

per hour (24 t/h).26 Annual iron foundry capacities averaged 118,000 tons (107,000 t) and

ranged from 100 to 1,368,000 tons (the latter being a large automotive foundry). The installed

capacity, based on the EPA survey, is about twice the cast iron production from cupolas in 1998. 

The total number of cupola furnaces has been decreasing over time, with replacement by

induction furnaces and electric arc furnaces to maintain industry capacity (Baldwin 1980). 

Energetics (1999) cites a figure of 144 cupola furnaces. The 1998 EPA survey also lists 144

cupolas including three very low tonnage prototypes.26 Baldwin (1980) reported that a typical

cupola producing a medium-strength cast iron from a cold charge would experience a melting

loss of 2% (as a percentage of iron input). Melting losses have been quoted elsewhere as 7% to

10% (Energetics 1999). A melt pouring temperature of 2,300 to 2,350oF (1,530 to 1,560 K) is

used for gray iron castings (U.S. Steel 1951).

Baldwin (1980) also documented the quantities of by-product material generated by a ductile

iron foundry using a cupola, and a gray and ductile iron foundry using a cupola for primary

melting, which duplexes into induction holding furnaces. The amounts of slag produced were

173 and 130 lb/ton (86.5 and 65 kg/t) of metal melted, respectively. According to Energetics

(1999), most slag is disposed of in landfills. In certain states, slag may be used in road

construction, after sizing and grading. However, the small volume of slag from an average

foundry does not allow for economical use of cupola slag in road construction. 

Using the results of several studies, EPA (1995a) has compiled emission factors for gray iron

foundries with various types of emission control devices used in conjunction with a cupola

furnace. These emission factors are summarized in Table 3.4.

The average value for uncontrolled emissions of 6.9 kg/t is based on four literature sources

specifying a range from 3.3 to 10 kg/t (Jeffery and Vay 1986, Table 4). Energetics (1999) cites

an American Foundry Society survey indicating that average cupola emissions are 13 to

17 pounds of particulates per ton of metal melted (6.5 – 8.5 kg/t), which is in good agreement

with Jeffery and Vay (1986). The data in Table 3.4 indicate a baghouse efficiency of 95% and

scrubber efficiencies ranging from to 42% to 95%. About 86% of all cupola furnaces have some

form of air pollution control device (APCD)—typically a fabric filter or a wet scrubber. All

large furnaces (i.e., > 40 tons/h [36 t/h]) have an APCD (Energetics 1999).
Recycling and Disposal of Steel Scrap Chapter 3

NUREG-1640 3-20

Induction Furnace Melting

A total of 675 facilities responded to a 1996 survey of iron and steel foundries by the EPA’s

Office of Air Quality Planning and Standards, indicating that 1,202 induction furnaces were

available. Less than 5% of the furnaces had melt rate capacities exceeding 10 tons per hour (~9

t/h) (Energetics 1999). Energetics noted that many small furnaces ranging from 2,000- to

15,000-lb (0.9 – 6.8 t) capacity are used by the foundry industry to reduce costs and improve

environmental performance. More recently, EPA has documented a total of 748 induction

furnaces at iron foundries and 643 induction furnaces at steel foundries.26 Reported iron foundry

melt rates ranged from 0.1 to 42 tons/h (90 kg/h – 38 t/h), with an average of 1.9 tons/h (1.7 t/h). 

Steel foundry induction furnace melt rates ranged from 0.025 to 8 tons/h (~23 kg/h – ~7 t/h) with

an average melt rate of 0.4 tons/h (~360 kg/h). The low end of the range includes numerous very

small furnaces which are probably not used for production. The combined annual capacities for

iron and steel casting furnaces averaged about 10 kt/y with a range from 4 t/y to 286 kt/y.

Table 3.4 Particulate emissions for cupola furnaces with various emission control devices

Control Device

Total Particulates

lb/tona kg/t

Uncontrolled 13.9 7.0

Scrubberb 3.1 1.6

Venturi scrubber 3 1.5

Electrostatic precipitator 1.4 0.7

Baghouse 0.7 0.35

Single wet cap 8 4

Impingement scrubber 5 2.5

High energy scrubber 0.8 0.4

Source: EPA 1995a, Table 12.10-3

a lb of pollutant/ton of gray iron produced

b includes averages for wet cap and other scrubber types not already listed.

Melt losses of 1% to 2% are reported for induction furnaces (Energetics 1999). Slag removal is

generally achieved by skimming. Removing slag from induction furnaces is difficult, because

the nature of the induction heating process causes the slag to remain relatively cold. Slag

volumes must be kept to a minimum and the use of slag/metal reactions for melt refining are

limited. Sulfur removal is also limited. These limitations are overcome, to some degree, by

using ladle adjustments to achieve desired chemistries in the cast metal. However, because the

induction furnace has limited refining capability, considerable care must be taken to control the

composition of the scrap metal feed to prevent melt contamination and insure that the desired

composition of the cast metal is achieved. Pelletized coke may be added to the melt to adjust its

carbon content (Baldwin 1980). Baldwin notes that the amount of slag from a malleable iron

foundry using induction-furnace melting is 34.53 pounds of slag per ton of metal melted (15.7

kg/t). 
Chapter 3 Recycling and Disposal of Steel Scrap

27 See Footnote 7 on page 3-6.

3-21 NUREG-1640

EPA (1995a) lists particulate emission factors for EAFs at gray iron foundries (g of pollutant/Mg

[t] of gray iron produced):

• Uncontrolled . . . . . . . . . . . . . . . . . . 500 g/t

• Baghouse ..................... 100 g/t

The uncontrolled emissions factor is the rounded off average based on two sources (410 and 500

g/t) (Jeffery and Vay 1986, Table 11). The above data imply that the baghouse efficiency is

78%.

According to Energetics (1999), over 75% of the induction furnaces with a capacity of more than

5 tons/h (> 4.5 t/h) have some type of APCD. But 72% of all induction furnaces had no APCD. 

The furnaces characterized in the study had melting rate capacities ranging from less than 5 to

more than 70 tons/hour (< 4.5 to > 64 t/h). About 87% of the furnaces included in the survey

had capacities of less than 5 tons/hour (< 4.5t/h) and about 95% had capacities of less than 10

tons/hour (< 9 t/h).

3.2.4 Output of Melting and Refining Processes

The four main outputs of the melting and refining process are dust or sludge that is captured

from the offgas, slag which is skimmed or poured off the molten metal, the metal product, and

airborne effluent releases—that portion of the offgas which escapes capture by the APCD.27

These process streams were discussed briefly in Section 3.2—more detailed discussions of

significant aspects of these media are presented below.

3.2.4.1 EAF Baghouse Dust

As was stated earlier, EAF baghouse dust is a RCRA-listed waste designated as K061. The

K061 regulations have continued to change since originally promulgated in 1988 and remain in a

state of flux. These regulations determine how the dust and its by-products can be used or

disposed of. The recent history of baghouse dust disposal is summarized in Table 3.5. The 1998

landfill data include 305,000 tons (277,000 t) (from 25 mini-mills) processed by Envirosafe

Services of Ohio, Inc., a wholly owned subsidiary of Envirosource Technologies, 55,000 tons

(50,000 t) processed by Northwestern Steel and Wire (NWSW), with the balance unidentified. 

Bagsarian (1999) quotes an Envirosource executive as stating that dust generation is now 40 to

60 lb per ton (20 to 30 kg/t) for new mini-mills and other upgraded mills. 

The temporal trends shown in Table 3.5 are largely driven by the changing regulatory climate at

EPA regarding RCRA materials, and to a lesser extent by the success or failure of various

treatment technologies. Prior to the RCRA regulations on the land-based disposal of hazardous

wastes in August 1990, most K061 wastes were shipped to landfills. Then, throughout the early

1990's, most of the waste was processed in Waelz kilns for metal recovery (HTMR-HRDC in
Recycling and Disposal of Steel Scrap Chapter 3

NUREG-1640 3-22

Table 3.5). In July 1995, EPA (1995b) ruled that K061 waste could be stabilized and sent to

nonhazardous waste landfills if the treated product passed the toxicity characteristic leaching

procedure (TCLP). At that time, EPA granted a generator-specific petition from Conversion

Systems, Inc. to delist certain solid wastes containing EAF dust that were stabilized by the Super

DetoxTM process for disposal in RCRA Subpart D landfills. Subsequent to that ruling, there has

been a significant shift back to landfill disposal (O’Neil 1998). 

Table 3.5 Disposal of EAF dust (1000 tons/y)

Disposal Route 1985 1992 1993 1995 1996 1997 1998

Landfill 337 63 82 143 220 365 400

Fertilizer 25 13 25 25 12 12

Micronutrients 16 17 17 16 16 16

HTMR-HRDCa 55 424 384 351 290 310 330

HTMR-ZNb 17 50 82 82 110 125 135

HTMR-Misc.c 0 10 14 33 52 61 60

Total 462 560 604 650 700 889 925

Sources: 1985 – 1997 data, EPRI 1998; 1998 data,Bagsarian 1999. a HTMR (High Temperature Metals Recovery) - HRDC (Horsehead Resource Development Co.)

b HTMR - ZN (Zinc Nacional) c Includes Laclede, MRT, HRDC-North Star Steel, Inorganic Recycling, International Mill Services (plasma arc

process, shut down and dismantled ca. 1996), ZTT (operations terminated August 1997). 1998 data include

Northstar - 27,500 tons, Nucor-Hickman - 9,000 tons, Nucor-Yamato - 9,000, and AmeriSteel (formerly with MRT)

- 7,400 tons, balance unidentified.

In addition, prior to July 24, 2002, K061-derived fertilizers were not subject to regulation as

hazardous wastes pursuant to 40 CFR 266.20(b), which stated that “zinc-containing fertilizers

using hazardous waste K061 that are produced for the general public’s use are not presently

subject to this regulation.” On that date, EPA (2002) promulgated revised regulations which

altered this exemption. Under the new regulations, zinc fertilizers are exempted from the RCRA

definition of solid waste, if the fertilizer meets certain limits on the maximum allowable

concentrations of As, Cd, Cr, Pb and Hg. Alternatively, the materials are exempted if they meet

the applicable treatment standards in 40 CFR 268 Subpart D for each hazardous waste

component contained. At the time the new regulation was promulgated, EPA had identified only

one fertilizer manufacturer who was processing K061 dust (from one steel mill) into zinc

micronutrient fertilizer.

As can be seen from Table 3.5, use of EAF dust in fertilizer and micronutrients accounted for

about 3% of the EAF dust disposed of in 1997.

As shown in Table 3.5, over 900,000 tons (820 kt) of EAF dust was disposed of in 1998. The

two largest domestic disposal approaches were high temperature metal recovery (HTMR) at

Horsehead Resource Development Co. (HRDC) and burial of stabilized, delisted waste in

landfills. As noted in Table 3.5, significant quantities are also processed outside the United

States (e.g., at Zinc Nacional, SA in Mexico).
Chapter 3 Recycling and Disposal of Steel Scrap

28 This "slag" is not a fused product as is the case for steel slags, since the kiln operates at a lower temperature than

a steelmaking furnace.

29 David J. Sosinsky, Horsehead Resource Development Company, Palmerton, PA, private communication with

William C. Thurber, SC&A, Inc., October 30, 1996.

30 Although EPA regulations would allow the stabilized dust to be disposed of in a RCRA Subpart D (nonhazardous) landfill, these two facilities conform to the requirements of RCRA Subpart C for hazardous waste disposal.

3-23 NUREG-1640

HRDC operates three regional Waelz kiln plants located in Palmerton, PA; Chicago; and

Rockwood, TN. These plants have a combined capacity of about 450,000 tons/y (~410,000 t/y)

(Bosley 1994, Schmitt 1996). In the HRDC process, EAF dust is mixed with coke or coal,

together with lime and silica, and fed into a rotary (Waelz) kiln about 120 to 180 ft (37 – 55 m)

long and 10 to 12 ft (3 – 4 m) in diameter, operating at about 1,100oC (Arthur D. Little 1993). 

The Zn and other volatile metals are collected in a baghouse as oxides (i.e., crude zinc oxide,

CZO). The baghouse product is sent to a second kiln where the Pb and Cd are fumed off and

collected from a baghouse for further treatment. The zinc oxide clinker is shipped to the Zinc

Corporation of America where it is processed in an electrothermal furnace (Foster 1991). The

clinker is a high quality zinc concentrate containing about 60% Zn. 

In the HRDC Waelz kiln process approximately 70% of the baghouse dust feed is converted to

"slag".28, 29 Disposal of this slag is a matter of ongoing regulatory review by the EPA. Antiskid/deicing applications of the slag are banned under 40 CFR 266.20. Other applications where

slag is placed on the land require that the slags meet the treatment standards specified by the

RCRA land disposal requirements (Bourdeau 1998).

Over the past several years, HRDC has been developing methods to recover iron and flux units

from the Waelz kiln slags so that they can be returned to the steelmaking process (Schmitt 1996). 

This iron-rich material has properties similar to DRI. Bagsarian (1999) stated that HRDC was

recycling 330,000 tons (300 kt) of EAF dust into Quickiron DRI. For example, Auburn Steel is

a customer for Quickiron DRI and uses about 700 tons (635 t) per month, which constitutes 2%

of its furnace feed.

EPA has granted Envirosource a multi-site delisting for materials produced by the Super

DetoxTM process (EPA 1995b). After treatment, the stabilized EAF dust can be managed either

at an Envirosource facility or at an approved RCRA Subpart D disposal facility (on site at the

steel mill or off site). Envirosource originally had two regional facilities: one near Toledo

(Envirosafe Services of Ohio, Inc.) and one in southern Idaho.30 (The Idaho facility was

acquired by American Ecology in 2001.) Capacities of these facilities are:

• Ohio—150 tons/h (136 t/h), stabilization capability of over 200,000 tons (180 kt) of waste

annually, 2 million tons (1.8 Mt) of permitted landfill capacity

• Idaho—over 100,000 tons (90 kt) per year stabilization capacity, over 2 million tons (1.8 Mt)

permitted disposal capacity
Recycling and Disposal of Steel Scrap Chapter 3

31 J. Wyett, Frit Fertilizer, personal communication with Mary Anderson, SAIC, February 1995.

NUREG-1640 3-24

Based on these capacities and the 1998 landfill data from Bagsarian 1999 (see Table 3.4), it

appears that Envirosafe is operating near capacity. American Ecology also operated an on-site

Super DetoxTM stabilization plant at NWSW at Sterling, IL. Stabilized waste was disposed of on

site at a landfill previously constructed and operated for steelmaking wastes. NWSW used wet

scrubbers rather than baghouses for air pollution control on its EAFs. The company suspended

operations in 2001—its assets were offered for sale at public auction in April 2002. In June

2002, a new company, Sterling Steel LLC, announced that it plans to operate a steel rod facility

at the NWSW site. It is not clear whether the operations will include an EAF. 

At the Super DetoxTM processing facilities, EAF dust is treated to obtain a waste form that meets

RCRA immobilization requirements. Typically about 100 g of EAF dust is mixed with about 30

g of two additives (liquid reagent and dry cement), which results in a dilution factor of 0.77; the

density of the solidified product is typically 1.36 g/cm3

 (Logan 1993). It is then loaded into steel

roll-off boxes or drums, which are temporarily stored in the yard. When laboratory tests confirm

that the waste meets EPA treatment standards, the containers are placed in the disposal trench. 

About 3% of the EAF dust was used for fertilizer and micronutrient applications in 1997 (see

Table 3.5). According to 40 CFR 266.20, which details use of EAF dust in fertilizer, such use is

no longer regulated under RCRA; however, this classification is subject to change. In this

application, fertilizer manufacturers treat the dust with sulfuric acid to form soluble zinc

compounds and insoluble lead sulfates. Fertilizer manufacturers require high zinc content

(preferably above 20%) in the dust (Arthur D. Little 1993) to achieve a reasonable maximum

concentration of zinc in fertilizer of 3%. Assuming that the initial concentration of zinc is 20%

in the EAF dust and that the final zinc concentration is 3% in enriched fertilizer, 28,000 tons

(25 kt) of EAF dust would be added to 159,000 tons (144 kt) of non-enriched fertilizer

(additives).31 All EAF dust shipped for use in fertilizer manufacturing is consumed during the

process. The enriched fertilizer is loaded into packing loaders, boxed, and shipped out on trucks.

EPA (1999) published a study which evaluated issues relating to heavy metals and other nonnutritive constituents in fertilizers and liming materials. The quantities of cadmium and lead

which would be added to soil each year as a result of the use of EAF dust as fertilizer are listed

in Table 3.6. These quantities are based on the assumption that zinc constitutes 15% of the dust.

Table 3.6 Buildup of heavy metals in soil from use of EAF dust as fertilizer

Metal Concentration in dust Annual application rate (kg/ha)

zinc 15% 5.6 11.2 22.4

cadmium 359 ppm 0.013 0.027 0.054

lead 1.917% 0.716 1.431 2.863

Source: EPA 1999, Table G-5a

Note: quantities of Cd and Pb concomitant to the application of EAF dust to achieve desired additions of Zn
Chapter 3 Recycling and Disposal of Steel Scrap

3-25 NUREG-1640

The disposition of EAF dust has been an issue for the steel industry for several years; as a result,

the EPA’s regulatory approach in this area is evolving. Because of the regulatory and liability

issues, industry has responded rapidly with new practices for the disposition of EAF dust; these

changing practices, however, make the process difficult to analyze. New recycling processes are

being developed to remove heavy metals and zinc oxide, producing various by-products such as

building bricks, roofing granules, and abrasives. Also, several approaches to minimize the

amount of dust requiring disposition are being investigated by the steel industry. This includes

efforts to minimize the generation of dust and various on-site recycling programs. There is

sufficient economic motivation and environmental liability to pursue such efforts, so practices

for the disposition of EAF dust will most likely continue to evolve.

3.2.4.2 Slag

Unlike EAF dust, steelmaking slag can be reprocessed for commercial use or disposed of in

nonhazardous waste landfills without special processing. Some commercial uses of steel slags

were discussed on page 3-6.

Based on steel production of 101 Mt in 2000, Kalyoncu (2002) estimated that the expected steel

slag production was 13 Mt. This estimate includes material from both BOFs and EAFs with

different slag generation rates. Of this, 5.1 Mt was sold or used as follows (Kalyoncu 2002):

• Asphaltic concrete aggregate .................. 0.9 Mt

• Fill . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.0 Mt

• Railroad ballast . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.4 Mt

• Road bases . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.7 Mt

• Other uses (ice control, soil conditioning, misc.) . . 1.1 Mt

Presumably, the unsold balance of about 5.5 Mt is either recycled to a sinter plant or landfilled

after recovery of metal values. 

Slag is transported from the melt shop to manufacturers or processors by either truck, rail, or

waterway. Of the slag sold in 2000, 78% was transported by truck, 6% by rail, and 16% by

water. Most slag was transported less than 100 km (Kalyoncu 2002). Truck transport is

typically in dump trucks with payloads of up to 25 tons (22.7 t). 

3.2.4.3 Metal Products

The line of steel products produced from EAFs and BOFs is not identical, but there is substantial

overlap between product lines. In the early stages of commercialization, EAFs tended to

produce a limited line of lower quality products such as rebar. Today, however, steel from EAFs

can be used in the production of about 80% of the same products as are manufactured from BOF

steel (Fruehan 1998). In some cases, a melt shop may produce blooms or slabs for sale to other

processors. Both product types follow the flow model presented in Figure 3.1. Metal products

are transported from the mill to manufacturers or processors by either truck, rail, or waterway.
Recycling and Disposal of Steel Scrap Chapter 3

NUREG-1640 3-26

Finished steel and cast iron products are used by consumers for innumerable applications,

covering the gamut from small objects in contact with the body (stainless steel jewelry), to

cookware, appliances and automobiles. One industry trade association has estimated that about

two-thirds of the weight of a passenger car is steel and cast iron and, of this, about 45% is

recycled metal (SRI 2002). In industrial settings, workers are frequently in close proximity to

massive steel objects and structures (e.g, crane operators, machinists, operators of earth-moving

machinery, etc.) 

3.2.4.4 Miscellaneous By-Products

There are other by-products from steelmaking in addition to slag and dust. However, these

constitute comparatively small amounts of material, and have not been addressed in the main 

analysis. One such by-product is mill scale, which is formed during the hot rolling of steel slabs. 

Scale consists of a mixture of iron oxides, and therefore has a high iron content (e.g., 55%). 

Scale production can be as high as 1% of steel product at a mill, but is more typically between

0.5% and 0.75%. Scale must be removed from finished steel because it results in unwanted

characteristics of the steel. Because of its high iron content and other characteristics, mill scale

is a commodity and can be used in the steel industry as well as the cement industry. Scoping

analyses of the potential radiological impacts of mill scale and other miscellaneous by-products, 

indicate that these products would not constitute significant sources of exposure. A detailed

discussion of these analyses is presented in Appendix N.

3.3 Mass Fractions and Partitioning Factors

For the purpose of the present analysis, the material entering an iron- or steelmaking furnace is

distributed into three process streams: metal product, slag, and offgas. The offgas consists of

gases and vapors as well as particulates. The particulates and the vapors that condense upon

cooling form dust, a portion of which is captured by the baghouse filters or other APCD. The

volatile fraction, as well as the particulates that escape the baghouse, are released to the

atmosphere. Any impurities (e.g., radionuclides) in the scrap metal are likewise distributed

among the metal, slag, dust, and volatile effluent emissions.

3.3.1 Mass Fractions

Table 3.7 presents a summary of the data characterizing iron- and steelmaking practices. Not all

of these data are directly utilized in the analyses: some are combined with other values to assign

values and/or uncertainty distributions to the parameters used in the calculations, while others

are presented as background information. Furthermore, there are minor discrepancies between

the data collected and the values of some of the parameters used in the analysis, due to rounding

or other approximations. The values of the mass flow parameters used in the analysis are listed

in Table B.3.
Chapter 3 Recycling and Disposal of Steel Scrap

3-27 NUREG-1640

 Table 3.7 Key data for development of mass flow parameters

Furnace type: BOF EAF Cupola Induction

Metal product carbon steel carbon, tool, stainless steel cast iron cast iron, steel

Fate of dust/sludge recycling, landfill

disposal 

metals recovery, fertilizer,

disposal in hazardous or

industrial landfill

landfill disposal landfill disposal

Furnace temperature 1873 K 1873 K 1548 K 1823 K

Metal product recoverya

 91% 90% 90 – 98% 98 – 99%

Scrap in feeda 24% 95.5% 91.5% 91.5%

Home scrapb 24% 25% 38% 38%

Dust/sludge generation 0.4 – 3.1%c 0.1 – 0.2%d 0.33 – 1.0%c 0.41 – 0.5c

Efficiency of APCD 99.4 – 99.9% 99.88 – 99.91% 95% max. 78% max.

Slag generation 5.0 – 22.0%c 12 – 14%c 6.5 – 8.6%d 1.57%c

Size of average heat 195 t 88 t 27 t/h 1.9 t/h

Average number of

heats/y per facility

6,023 4,405 n/a n/a

a With respect to total metal in furnace charge

b With respect to total scrap in furnace charge 

c With respect to metal produced

d With respect to scrap melted

3.3.1.1 Furnace Charge

The fraction of the total furnace charge that is comprised of scrap varies with the melting

process. In EAFs the charge is largely scrap. According to the Steel Recycling Institute (SRI

2001), 95.5% of EAF output is from scrap. Fenton (2000) reported that scrap accounted for 24%

of BOF steel produced in 2000. Data from the same source indicates that 91.5% of the feed to

iron foundries is scrap.

As discussed previously, a significant fraction of the scrap is home scrap. The amount of home

scrap depends on the melting process. The Steel Recycling Institute (SRI 2001) has estimated

that about 25% of the scrap charged into an EAF is home scrap. The same source estimates that

about 24% of the BOF scrap charge is internally generated (e.g., home) scrap. Based on industry

data for 1998, complied by the U.S. Geologic Survey, it can be estimated that about 38% of the

scrap used in producing iron and steel castings is home scrap (Fenton 1999, Table 2). Data for

2000 yields the same value within the precision of the listed data (Fenton 2002, Tables 2 and 4).
Recycling and Disposal of Steel Scrap Chapter 3

NUREG-1640 3-28

3.3.1.2 Metal Product

Industry data indicate that EAFs typically produce 90 t of steel for every 100 t of scrap used

(Lankford et al. 1985), resulting in a mass fraction of 0.9. Anigstein et al. (2001, Section E.7)

derive the same value, using an argument based on mass balance. Average metal product

recovery for BOFs has been quoted as 91% (Fruehan 1998). These data are used indirectly to

convert mass fractions in terms of metal in the furnace charge to mass fractions in terms of metal

produced.

For cupola furnaces melting cast iron, recoveries have been variously cited as 98% (Baldwin

1980) and 90% to 93% (Energetics 1999). For induction furnaces melting cast iron, metal

recoveries have been quoted to range from 98 to 99% (Energetics 1999). These values are

quoted for the purpose of background information—they are not used in the present analysis.

3.3.1.3 Baghouse Dust and Sludge

There is reasonable consistency in the literature for dust generation rates from melting of carbon

steel at EAF facilities. Brough and Carter (1972) and Venturini (1970) give 15 kg/t as a

“measured operating value.” Arthur D. Little (1993) presents 15 kg/t of capacity as an industry

average of 52 plants responding to their survey. Estimates of the ranges of dust production

among various mills are also fairly consistent. Brough and Carter (1972) cite a range of 7.5 to

20 kg/t as a specification for baghouse design; Elert and Wiborgh (1992) cite a range of 10 to 15

kg/t for Swedish EAF steel mills; Szabo and Gerstle (1978) give a range of 12 to 29 kg/t; and

Fruehan (1998) quotes a range of 10 to 20 kg/t of scrap melted. A range of 10 to 20 kg of dust

generated per tonne of metal charged to the furnace, with a best estimate of 15 kg/t, is adopted

for the present analysis. 

More limited data are available for BOFs. According to AISI 1998, Chapter 4, BOF dust ranges

from 4 to 31 kg/t of raw steel produced, with an average of approximately 18 kg/t. These values

are adopted for the present analysis.

Cupola furnaces used to melt cast iron have uncontrolled emissions (i.e., total emissions prior to

filtration or other APCD, if any) ranging from 3.3 to 10 kg/t of gray iron produced, with an

average of 6.9 kg/t. Uncontrolled emissions from induction furnaces at gray iron foundries are

about an order of magnitude lower, with a range of 0.41 to 0.5 kg/t of metal produced and an

average value of 0.45 kg/t (Jeffery and Vay 1986).

A fraction of the furnace dust will escape the air pollution control device and be released from

the stack together with gaseous products. As cited on page 3-18, EAF baghouse efficiencies

range from 99.88% to 99.91%, while the filtering system efficiencies in BOF shops can range

from 99.4% to 99.9% (see page 3-14, above). Baghouse efficiencies of 95% for cupola furnaces

and 78% for induction furnaces melting cast iron are cited on pp. 3-19 et seq. However, not all

furnaces use APCDs.
Chapter 3 Recycling and Disposal of Steel Scrap

32 Rick West, Sales Manager for International Mill Services, private communication with William C. Thurber,

SC&A, Inc., June 25, 1996.

33 This concept is a generalization of the partition coefficient used in chemistry, but differs from the latter in three

significant respects: (1) the partition factor refers to the total amount (not concentration) in the furnace product; (2) it is

the ratio of this amount to the original amount in scrap, not the equilibrium concentration; and (3) it includes the volatile

fractions as well as the amounts that collect in dust, and is therefore not restricted to liquid phases.

3-29 NUREG-1640

3.3.1.4 Slag

The mass fraction of BOF slag is assigned a range of 50 to 220 kg/t of steel produced, with an

average value of 120 kg/t slag, based on AISI 1998, Chapter 4. A major slag marketer estimates

that 120 to 140 kg of slag per tonne of steel are produced at an EAF.32 Based on additional

reviews of data for EAF slag generation, a range from 120 to 140 kg/t of steel produced, with a

mean value of 130 kg/t, was adopted for the present analysis.

Slag generation rates are lower in cast iron melting than in steel melting. Values of 65 and 86.5

kg/t of metal melted have been cited for cupola furnaces melting gray iron and/or ductile iron

(Energetics 1999). For induction furnaces melting malleable iron, a slag generation rate of 15.7

kg/t of metal melted has been cited by Baldwin (1980). 

3.3.2 Partitioning Factors

An analysis of the redistribution (partitioning) of the residual activities of cleared steel scrap

entering a melting furnace is needed to determine the radionuclide concentrations in each of the

furnace products mentioned earlier. Since all isotopes of a given element have virtually identical

chemical properties, the partitioning of the various radioisotopes can be determined from the

partitioning of the stable isotopes of the same elements, or of other radioisotopes for which

partitioning data exist. A partitioning factor is defined as the ratio of the total amount of a given

element or compound in one of the furnace products to the amount in the scrap metal charged to

the furnace.33

This section presents the basic assumptions and methodology used in developing the partitioning

factors of impurities (including radionuclides) during melting and refining.

3.3.2.1 Basic Assumptions

Many of the elements included in the partitioning studies, with the exception of the actinides, are

typically found in steelmaking as components of steel scrap, alloying additions, slag-forming

agents, or unwanted impurities. Sulfur, for example, is usually an unwanted impurity in steel. 

However, sulfur and other chalcogenides are sometimes added to alloys to produce freemachining steels. As noted in Appendix J, a typical low carbon steel (SAE 1020) contains

 0.05% S. A free machining steel—SAE 1118—contains 0.08% to 0.13% S. In general,

steelmaking processes and operating conditions have been developed that can maximize the

retention of a particular element in the molten steel, depending on the desired result, or,
Recycling and Disposal of Steel Scrap Chapter 3

NUREG-1640 3-30

conversely, maximize its removal. The elemental partitioning factors determined for the present

analysis are intended to be representative of the expected behavior during melting in a typical

domestic EAF or BOF. While some differences might be expected in the partitioning of

impurities in these different steelmaking furnaces, sufficient information is not available to

quantify these differences. A separate set of partitioning factors was developed for cast iron

melting.

It is recognized that there would be variability in the behavior of impurities during the refining of

steel. For example, cesium may almost completely volatilize to the dust if a basic slag is used,

but would tend to partition to both the slag and dust if a neutral or acidic slag is used

(Harvey 1990). Details on cesium partitioning are presented in Section J.1.4.7. Other factors

that could affect the partitioning factors are gas sparging, mixing, or the type of desired melt

(e.g., carbon steel or stainless steel). Thus, any single partitioning value used in the analysis has

some associated uncertainty. In order to address this uncertainty, probability distributions are

assigned to the partitioning factors.

The main components of a typical melt shop that play significant roles in the analysis are the

primary melting chamber (the furnace) and the APCD. As stated previously, the latter system

typically consists of a fabric baghouse filter, a scrubber, or an electrostatic precipitator. Other

components of the melt shop, such as ladles, tundishes, and reheating ovens, are not important to

the analysis because no phase changes occur and there is no dilution or concentration of

radioactive contaminants. The most common types of steel melting furnaces use a basic slag

(Lankford et al. 1985). Other processes, such as the use of different slagging agents, gas

sparging, and mixing, can affect partitioning of impurities. However, these processes are not

included in the present analysis because their use in iron and steelmaking is extremely variable

and their effects are difficult to predict. Such special processes fall outside of mainstream

steelmaking.

During melting and refining, impurities can partition to one or both of the liquid components

(i.e., the slag and metal phases), or discharge from the furnace in the volatilized gas. Some of

the impurities that leave the furnace in the volatilized gas will remain in the vapor phase and

some will condense or coalesce into particulates (dust). Impurities found in coarse particulates

are captured by the APCD. Some of the fine particles and species in the vapor phase will escape

in the airborne effluents exiting the stack. A small fraction of metals and oxides that are

refractory or ferrous in nature will be carried over to the dust.

3.3.2.2 General Methodology for Determining Partitioning of Impurities

The distribution of impurities during melting and refining of steel or cast iron is a complex

process that can be influenced by numerous chemical and physical factors, including

composition of the steel bath, chemistry of the slag, vapor pressure of the particular chemical

species, solubility of the element in molten iron, density of the oxide(s), steel-melting

temperature, and melting practice (e.g., furnace type and size, melting time, method of carbon

adjustment, and method of alloy additions).
Chapter 3 Recycling and Disposal of Steel Scrap

3-31 NUREG-1640

The general methodology employed here was to first consider metal/slag reactions based on

thermodynamic calculations (i.e., Gibb’s free energy) to determine whether an element was

likely to partition to the slag or to the melt. To accomplish this, the free energy change for the

following general reaction written here between a divalent solute element M (e.g., Co) and iron

oxide in the slag was evaluated at 1600°C (1873 K):

M + FeO(slag) = MO(slag) + Fe(l)

where M is the symbol for solute dissolved in liquid iron and Fe(l) is iron in the melt. From these

calculations, partition ratios describing the distribution of the element between the melt and the

slag are developed. The detailed methodology is presented in Section J.1.1 of Appendix J. 

Elements that form highly stable oxides (e.g., actinides and lanthanides) will tend to partition

strongly to the slag. Elements whose oxides are less stable than FeO would tend to remain in the

melt (e.g., Co, Ni, Tc). 

The vapor pressures of the more volatile elements and their oxides were examined to gain insight

into which elements would tend to concentrate in the dust leaving the furnace. Elements such as

cadmium, cesium, polonium, and zinc all have normal boiling points well below 1873 K and

would be expected to volatilize from the melt and be concentrated in the dust. 

These theoretical considerations were supplemented with a review of the steelmaking and

nuclear metallurgy literature to obtain industrial and laboratory data on observed partitioning of

various elements during steel melting. In some instances, no thermodynamic or literature data

were available. In such cases, partitioning is based on chemical analogy with similar elements. 

For example, the lanthanides, Pm and Gd, are assumed to behave in a manner similar to Ce and

Sm, for which data are available. 

In some cases, only a single data point is available and so a fixed percentage for the elemental

partitioning is assigned to each process stream. If multiple sources of data were available, a

range of values representing the combined sources is established. Since, in many cases,

thermodynamic and vapor pressure data only indicate tendencies as to how elements partition

rather than quantitatively fix the specifics of the distribution among process streams, engineering

judgment is employed to quantify these tendencies. The convention is adopted that, if an

element tends to remain in the melt, 1% is assumed to be transported to the dust due to physical

entrainment associated with the turbulence of the melting and refining process. Similarly, if an

element tends to partition to the slag, 5% is assumed to be transferred to the dust. The detailed

rationale for these conventions is provided in Section J.1.7.

Table 3.8 lists the ranges of partitioning factors (during steelmaking) of each element that is

represented by one or more radioisotopes in the present analysis. Probability distributions, most

often employing beta functions, are developed to represent the range of variability and/or

uncertainty in these factors, using the methodology described in Section J.5. The parameters that

specify each of these distributions are listed in Table B.2. Similar data for cast iron production

are presented in Table 3.9.
Recycling and Disposal of Steel Scrap Chapter 3

NUREG-1640 3-32

 Table 3.8 Partitioning in steelmaking (%)

Elements Metal

product Dust Slag Volatile

H 5–15 0 0 85–95

C 27–100 0 0 0–73

Na, K 0 40–60 40–60 0

P 9–48 2–4 50–87 0

S 6–25 1–5 74–89 0

Cl, I 0 0–50 0–50 0–100

Ca, Sc, Sr, Y, Zr, Nb, Ba, Ce, Pm, Sm, Eu, Gd, Tb, Tm,

Ta, Ra, Ac, Th, Pa, U, Np, Pu, Am, Cm, Bk, Cf, Es 0 2.5–7.5 92.5–97.5 0

Cr 40–97 1–3 0–59 0

Mn 2–24 3–4 72–95 0

Fe 95.5–98.5 0.5–1.5 1–3 0

Co, Ni, Mo, Tc, Ru, Sn, W, Ir 98.5–99.5 0.5–1.5 0 0

Zn 0–20 80–100 0 0

As 50–90 10–50 0 0

Se, Te, Os, Tl, Pb, Bi, Po 2.5–7.5 92.5–97.5 0 0

Ag 75–99 1–25 0 0

Cd 0 100 0 0

Sb 75–99 1–20 0–5 0

Cs 0 95–100 0–5 0

3.4 Mixing of Cleared Scrap

The concentration of each radionuclide in cleared scrap would be reduced by mixing with other

materials, including scrap from other sources, prior to melting. Further mixing occurs during the

disposal of furnace by-products. The mixing of cleared scrap and of products and by-products of

the melting and refining of the scrap are briefly discussed in this section. The type of mixing

factor used in each exposure scenario is listed in Table 3.10. A detailed discussion of all mixing

factors used in the present analysis is presented in Appendix D. 

3.4.1 Processing Scrap at Scrap Yard

It is assumed that all the steel scrap cleared during the dismantlement of a commercial nuclear

power plant during one year is processed by a single scrap dealer. The mixing at the scrap yard

is modeled by calculating a mixing factor, which is the mass of steel scrap cleared from a nuclear

facility in one year, divided by the annual throughput of the scrap yard. 
Chapter 3 Recycling and Disposal of Steel Scrap

3-33 NUREG-1640

3.4.2 Melting and Refining of Scrap

3.4.2.1 Annual-Average Mixing Factors

The mixing of scrap in the furnace is modeled as a multi-step process. The first step consists of

selecting the type of furnace which would receive the scrap. For the purpose of the present

analysis, furnaces recycling steel scrap are grouped into three classifications, as discussed in

Section 3.2. The probability that the cleared scrap would be recycled at any particular furnace is

assumed to be proportional to the annual scrap consumption of that furnace. The following

probabilities are assigned to the three furnace types:

• BOF . . . . . . . . . . . . . . . . . . . . . . . . . . . 20%

• EAF . . . . . . . . . . . . . . . . . . . . . . . . . . . 58%

• Iron and steel foundries . . . . . . . . . . . . 22%

 Table 3.9 Partitioning in cast iron melting (%)

Elements Metal

product Dust Slag Volatile

H 5–15 0 0 85–95

C, Cr, Fe, Co, Ni, Mo, Tc, Ru, Ag, W, Ir 99–100 0–1 0 0

Na, K, Cs 0 50–100 0–50 0

P 9–48 2–4 50–87 0

S 6–25 1–5 74–89 0

Cl, I 0 0–50 0–50 0–100

Ca, Sc, Sr, Y, Zr, Nb, Ba, Ce, Pm, Sm, Eu, Gd, Tb, Tm,

Ta, Ra, Ac, Th, Pa, U, Np, Pu, Am, Cm, Bk, Cf, Es 0 2.5–7.5 92.5–97.5 0

Mn 96–99 0–1 0–4 0

Zn 1–3 97–100 0 0

As 50–90 10–50 0 0

Se 89.5–96.5 3.5–10.5 0 0

Cd, Po 0 100 0 0

Sn 98.5–99.5 0.5–1.5 0 0

Sb 2–6 94–98 0 0

Te 40–60 40–60 0 0

Os 2.5–7.5 92.5–97.5 0 0

Tl, Pb 4–10 90–96 0 0

Bi 3–7 93–97 0 0

Each type of furnace uses a different mix of purchased scrap, home scrap, and virgin metal, as

shown in Table 3.7.

As discussed in Section 3.2.3, the annual scrap consumption among furnaces of a given type

covers a wide range. In order to determine mixing factors for the range of iron- and steel making

furnaces and melt shops in the United States, data were collected and tabulated on the annual
Recycling and Disposal of Steel Scrap Chapter 3

34 These facilities typically have two or more furnaces. However, the furnaces operate together and share the same

scrap metal supplies.

35 In the infrequent case that the mass of cleared scrap is greater than the annual scrap consumption of a given

furnace, the mixing factor is simply the ratio of purchased scrap to the metal poured.

36 In the case noted in Footnote 35, the balance of the lot would be consumed by a different furnace.

NUREG-1640 3-34

production capacities of 23 BOF shops,34 168 EAFs, and 1703 furnaces at iron and steel

foundries. The mixing factor is the ratio of the cleared scrap (generated during one year of

dismantlement of a nuclear power reactor) to the annual production capacity of given furnace. 

(Because the mixing is averaged over one year of production, the calculated ratio is called the

“annual-average mixing factor.”) The furnace, as mentioned earlier, is selected at random from a

distribution of furnace sizes, weighted by the number of furnaces in each size category and by

the average scrap consumption of the furnaces in that category: a furnace which consumes a

large amount of scrap is more likely to be the recipient of a particular batch of scrap than a small

furnace.35

This process can be visualized by assuming that the scrap cleared in one year remains, for the

purpose of the recycling analysis, as one indivisible lot.36 This lot, however, joins the

nationwide flow of scrap and therefore follows the same paths as the rest of the scrap destined

for recycling. 

3.4.2.2 Maximum Single-Heat Mixing Factors

Section 3.4.2.1 discussed the calculation of annual-average mixing factors at furnaces melting

steel scrap cleared from a nuclear facility. However, over the course of a year, the proportion of

cleared scrap will vary from one furnace heat to another. At a large furnace, for which the

annual consumption of purchased scrap is much greater than the amount that would be cleared

by a nuclear facility during one year, many heats may contain no cleared material—the mixing

factor for such a heat would be zero. Conversely, some heats would contain much more than the

annual-average ratio of cleared material. The maximum single-heat mixing factor is the ratio of

cleared scrap to the mass of metal poured in the single furnace heat produced during one year

that contains the maximum fraction of cleared scrap. 

This mixing factor depends on the furnace type. Cupola furnaces producing cast iron can melt a

charge consisting of a single grade of scrap. Consequently, it is conceivable— indeed

likely—that all the old scrap in at least one heat would consist of cleared material. EAFs, on the

other hand, require different grades of scrap. At the beginning of a melt cycle, light shredded

scrap is added to facilitate melting and prolong electrode life. As the melt progresses, heavier

grades are added. According to a steel industry source, a single EAF heat would include steel
Chapter 3 Recycling and Disposal of Steel Scrap

37 Thomas A. Danjczek, President, Steel Manufacturer’s Association, private communication with Robert

Anigstein, SC&A, Inc., 1999.

3-35 NUREG-1640

3.1

from 5 to 20 sources.37 Consequently, a distribution of single-heat mixing factors was

constructed and utilized for both EAF and BOF facilities. 

3.4.2.3 Mixing of Waste in the Landfill

The analyses of the landfill disposal of cleared scrap, slag, or BOF/foundry dust assume that one

year’s material from a given nuclear power plant or melt shop would be emplaced in a single

landfill, commingled with other wastes received by that landfill over the course of a year. The

mixing of the disposed scrap or dust is determined by dividing the quantity of such material by

the annual volume of all wastes disposed of at a given landfill.

3.4.2.4 Mixing of EAF Dust During Processing and Disposal

The analysis assumes that the scrap from only a single nuclear power plant is sent to any given

scrap yard, landfill, or melt shop. In most cases, it is assumed that the furnace products of a such

a melt shop are disposed of in a landfill or processed for further use at other facilities, none of

which receive any other residually radioactive materials. This is a reasonable assumption for

most scenarios, since the number of disposal, processing, or recycling facilities in the United

States is far greater than the number of nuclear power plants which would undergo

dismantlement in any one year. Therefore, the probability that scrap from two or more nuclear

power plants would be processed in the same scrap yard, disposed of in the same landfill,

recycled in the same melt shop, etc., is very small.

This assumption is not valid for the processing and disposal of EAF dust. As discussed in

Section 3.2.4.1, there are only two currently operating facilities that process EAF dust for

disposal and subsequently dispose of such dust in on-site landfills. In 1998, there were seven

operating HTMR facilities in the United States (see Table 3.5). Since there is no way of

predicting which EAF dust disposal option would be selected by a given steel mill, nor which

facility the dust would be sent to, it is reasonable to assume that the dust from any given mill

would be mixed with the nationwide stream of EAF dust. This stream would, of necessity,

include EAF dust from all other steel mills that are simultaneously recycling steel scrap from the

dismantlement of other nuclear reactors.

The dilution for the EAF dust processing scenario is calculated as follows:

dfr = mixing factor for EAF dust during processing or disposal
Recycling and Disposal of Steel Scrap Chapter 3

38 Greg Ballmer, Envirosafe Services of Ohio, Inc., private communication with Kathleen Behling, SC&A, Inc.,

March 13, 2002. 

NUREG-1640 3-36

fE = fraction of steel scrap recycled at EAFs

= 0.58

md = mass of dust generated by EAF (g)

nD = total number of nuclear plants undergoing dismantlement in a given year

Mt = annual amount of EAF dust generated in United States

= 9.25 × 105 tons (8.39 × 1011 g) (see Table 3.5)

The number of nuclear plants undergoing dismantlement in any one year is sampled from a

distribution, based on the dates of license expirations of NRC-licensed nuclear power reactors

listed in NRC 2000, Table 12. The period of dismantlement is assumed to be 1.7 years. Years in

which no dismantlement is projected are excluded from consideration.

Additional factors are needed in Equation 3.1 to calculate the mixing factor in the scenario

describing the disposal of EAF dust in a hazardous waste landfill:

dfH = dilution factor for stabilization process

= 0.77

Fd = fraction of EAF dust in waste stream

= 0.7538

3.5 Radionuclide Concentrations During Melting and Refining 

3.5.1 Annual-Average Concentrations

Five factors affect the radionuclide concentrations in the furnace products: (1) initial activity

concentration (specific activity) in the scrap, (2) mixing of cleared scrap with other metals

(purchased scrap from other sources, virgin metal, and home scrap), (3) mass fraction of the

given medium (i.e., furnace product), (4) partitioning factor of the element in question, and

(5) radioactive decay and progeny ingrowth. For the purposes of calculating the normalized

doses, which is the aim of the present analysis, the initial specific activity is assigned a value of

unity. Mixing, mass fractions, and partitioning factors are discussed in Sections 3.3 and 3.4. 

Radioactive decay is addressed in Sections 3.6 and 3.7. 

The annual average concentrations, not accounting for radioactive decay and progeny ingrowth,

are calculated as follows:
Chapter 3 Recycling and Disposal of Steel Scrap

3-37 NUREG-1640

3.2

3.3

3.4

Cij = concentration of nuclide i in medium j (Bq/g)

Cis = average concentration of nuclide i in purchased scrap + virgin metal (Bq/g)

fhk = fraction of home scrap used in furnace type k (BOF, EAF, or “other”)

= ghkfsk

ghk = fraction of scrap in furnace type k derived from home scrap (see Table B.3)

fsk = total fraction of scrap in type k furnace charge (see Table B.3)

fip = partition factor of nuclide i in metal product (see Table B.2)

fij = partition factor of nuclide i in medium j (see Tables B.2)

fpk = mass fraction of metal product in furnace type k, in relationship to metal charged to

furnace (see Table 3.7)

fjk = mass fraction of medium j in furnace type k, in relationship to the molten metal

poured (see Table B.3)

The annual release of volatile nuclides can be calculated as follows:

Aiv = total activity of nuclide i volatilized during one year (Bq)

Cio = concentration of nuclide i in cleared scrap (Bq/g)

fia = fraction of nuclide i volatilized from furnace

Mo = total mass of cleared scrap charged to furnace in one year (g)

The activity calculated in Equation 3.3 does not include the activity in the dust that is released to

the atmosphere. The latter quantity is calculated as follows:

Aid = total activity of nuclide i released in airborne dust during one year (Bq)

Cid = concentration of nuclide i in dust (Bq/g)

fdk = mass fraction of dust in furnace type k, in relationship to molten metal poured (see

Table B.3)

mp = total mass of metal produced in one year (g)

= annual production capacity of particular furnace or melt shop
Recycling and Disposal of Steel Scrap Chapter 3

NUREG-1640 3-38

3.5

k = efficiency of APCD for furnace type k

The total mass of slag and dust produced in a year is equal to the annual mass of metal produced

multiplied by the mass fraction of slag or dust:

mjk = mass of product j produced by furnace of type k during one year (g)

3.5.2 Maximum Single-Heat Concentrations

Equations 3.2 – 3.4 are used to calculate the radionuclide concentrations in scenarios in which

the source of the activity is averaged over one year’s output of the mill. This includes all

scenarios where the exposure is to slag or dust, since these materials are processed, handled, and

transported in a continuous stream. It also applies to the handling of finished metal at the melt

shop, and to the transport of such metal. In all scenarios where the exposure is to a single item

(or batch of items) made from such metal, it is conservatively assumed that each of these items

was made from the single heat that contained the highest fraction of scrap at a given melt shop

over the course of a year. 

To calculate the radionuclide concentrations in metal produced from the maximum single heat,

Equation 3.2 is modified as follows:

Sip = concentration of nuclide i in metal produced from maximum single heat (Bq/g)

Sis = concentration of nuclide i in purchased scrap + virgin metal in maximum single

heat (Bq/g)

Cip = annual-average concentration of nuclide i in metal (see Equation 3.2) (Bq/g)

Appendix K lists the mean and the 5th, 50th, 90th, and 95th percentile normalized undecayed

concentration of each radionuclide in the furnace products of an EAF. The maximum single-heat

concentrations in the metal product are calculated according to Equation 3.5, while the annualaverage concentrations in the metal product, slag and dust are calculated according to

Equation 3.2. The total annual activity released to the atmosphere is the sum of the activities

calculated by Equations 3.3 and 3.4. All concentrations and released activities are normalized to

unit specific activity in scrap. Appendix K also lists the corresponding data for BOF and cast

iron furnaces, respectively. 

3.6 Exposure Pathways

As was noted in Section 1.6, the exposure pathways included in the present analysis fall into two

categories: external and internal. 
Chapter 3 Recycling and Disposal of Steel Scrap

3-39 NUREG-1640

3.6

3.6.1 External Exposure

The general methodology of assessing external exposure is similar for all the radiological

assessments in the present analysis. This pathway discussed in Section 1.6.1. For the purpose of

assessing the dose from external exposure, the exposure scenarios fall into two broad categories:

1. Scenarios where the source of exposure is a steady stream of residually radioactive material. 

2. Product use scenarios, where the individual is exposed to the same product during the entire

assessment period.

3.6.1.1 External Exposure to a Steady Stream of Material

External exposure to a steady stream of residually radioactive material is assessed as follows:

Dix = dose from external exposure to nuclide i during assessment period (:Sv)

Cij = average activity concentration of nuclide i in medium j (from Equation 3.2)

(Bq/g)

Fix = dose coefficient for external exposure to nuclide i (:Sv/h per Bq/g)

txy = exposure duration during assessment period (h)

Ux = uncertainty factor

i = radioactive decay rate of nuclide i (d-1)

ts = interval from time scrap is cleared until scenario begins

The parameters Fix and Ux are defined and discussed in Section 1.6.1. Unique aspects, specific to

the individual scenarios, are discussed as part of the description of each scenario. Additional

details are presented in Appendix C. 

Strictly speaking, Equation 3.6 applies only to nuclides without radioactive progenies (other than

the short-lived progeny assumed to be in secular equilibrium with the parent—see Appendix E),

or to the parent nuclide of a radioactive decay chain. The dose contribution of progeny that

exhibit significant ingrowth before or during the assessment period is explicitly included by

modeling this ingrowth by means of the Bateman equations. The reported dose from a nuclide

having such progeny includes this contribution. A complete list of both short-lived and longerlived progenies included in the analysis appears in Table E.1. 

The same comment applies to all calculations of radionuclide concentrations in the present

analysis.
Recycling and Disposal of Steel Scrap Chapter 3

NUREG-1640 3-40

3.7

3.8

3.6.1.2 External Exposure to Single Product

Doses from external exposure to a single product are calculated as follows:

Dix = dose from external exposure during assessment period (:Sv)

ta = assessment period (d)

3.6.2 Internal Exposure

Internal exposure comprises two principal pathways: inhalation, and ingestion. A general

discussion of the dose assessment of these pathways is presented in Section 1.6.2. A more

specific discussion of the inhalation pathway, which is applicable to the assessment of steel

scrap—and of other materials presented in Chapters 4 to 6—is presented below, followed by a

discussion of inadvertent ingestion of particulate matter (secondary ingestion). Ingestion of

residually radioactive food and water, and inadvertent ingestion of soil, are discussed as part of

the description of the scenarios that include these pathways.

3.6.2.1 Inhalation Exposure

In some work-related scenarios, some of the material being handled or processed (e.g., metallic

particulates, slag, or EAF dust) would be dispersed into the air and inhaled by the exposed

individual. The dose due to this exposure pathway is calculated as follows:

Dih = dose from inhalation of radionuclide i during assessment period (:Sv)

Fih = dose conversion factor (or dose coefficient) for inhalation of radionuclide i

(:Sv/Bq)

Rh = inhalation rate (m3

/h)

tiy = duration of internal exposure during assessment period (h)

3d = airborne concentration of dust (mass loading) (g/m3)

The internal dose conversion factors used to calculate the effective dose equivalent (EDE) and

the corresponding dose coefficients used to calculate effective dose are discussed in Section

1.6.2. The specific activities of airborne particulates are assumed to be the same as those of the

material from which those particulates are generated, except in scenarios where the composition

of the particulates is different than the composition of the originating material. These exceptions

are discussed in the descriptions of the scenarios in Section 3.7. 
Chapter 3 Recycling and Disposal of Steel Scrap

3-41 NUREG-1640

3.9

Inhalation exposures also result from the emissions of airborne effluents from furnaces recycling

steel scrap. These are described as part of the discussion of that scenario.

Inhalation Rate

Two methods used to estimate inhalation rates for dose assessments are: (1) the tidal volume

and frequency method (ICRP 1975, ICRP 1994, and EPA 1997), and (2) the method using

oxygen demand based on metabolic conversion of food nutrients (Layton 1993). Although the

latter method takes into account variations in oxygen uptake efficiency, lung physiology, and

metabolic efficiency among individuals, it is not as widely accepted as the tidal volume method.

Both EPA and ICRP base their average hourly inhalation rates on the tidal volume (L/breath)

and the frequency (breaths/minute) for various activity levels; that is the method adopted for this

study.

The inhalation rates in ICRP 1975 and EPA 1997 were reviewed to determine a reasonable range

for the present analysis. ICRP 1975 lists an inhalation rate of 20 L/min for an adult man and 19

L/min for an adult woman. In calculating the regional deposition of inhaled aerosols in the

Reference Worker, ICRP 1994 assumes inhalation rates for light activity which have a timeweighted average of 1.2 m3

/h (20 L/min). This value was adopted as both the mean and the most

likely value in estimating the inhalation exposures of workers in the present analysis. EPA 1997

(Chapter 5) cites a number of studies performed under a variety of conditions. The study which

agrees best with the ICRP model—the field protocols reported by Adams—lists a mean adult

inhalation rate of 0.6 m3/h for sedentary activities, 1.2 m3/h for light activities, and 1.8 m3/h for

moderate activities. Based on these data, this parameter was assigned a triangular distribution,

with a mode of 1.2 m3/h and a range of 0.6 – 1.8 m3/h.

Although both higher and slightly lower inhalation rates for various activities have been

reported, our purpose in assigning values to this parameter is to estimate the inhalation exposures

of members of the critical group over the course of one year. An individual experiencing a high

inhalation rate during heavy exertion would not maintain such a rate during his entire workday,

much less during every workday over the course of a year. 

3.6.2.2 Inadvertent (Secondary) Ingestion

Material that is dispersed into the air would also be deposited on accessible surfaces. Secondary

ingestion comprises the ingestion of residually radioactive material from contaminated hands

and food. Every work-related scenario assessment that includes the inhalation pathway also

includes inadvertent secondary ingestion. The dose from this exposure pathway is calculated as

follows:

Dig = dose from ingestion of radionuclide i during the assessment period (:Sv)

Fig = dose conversion factor for ingestion of radionuclide i (:Sv/Bq)

Is = secondary ingestion rate (g/h)
Recycling and Disposal of Steel Scrap Chapter 3

39 Norb Geiss, The David J. Joseph Company, private communication with Robert Anigstein and William C.

Thurber, SC&A, Inc., February 14, 2003.

NUREG-1640 3-42

The rate of secondary ingestion is a highly uncertain parameter. EPA 1997 presents a detailed

discussion of soil and soot ingestion, primarily by children. Estimates of daily ingestion by

adults range from 0.56 mg of “housedust” during “typical living space activities” to 480 mg of

soil while gardening. Table 4-15 of EPA 1997 cites an adult soil ingestion rate from gardening

of 20 mg/h, cited by Sheppard for assessment purposes. This appears to be a reasonable estimate

of the maximum hourly rate, averaged over one year of exposure in a work-related scenario, and

is the value adopted for the exposure of the “reasonably maximally exposed individual” in the

scrap metal recycling assessments by Anigstein et al. (2001). A minimum value of the ingestion

rate is zero. This corresponds to the ingestion of workers practicing good industrial hygiene. 

Some scrap metal processors, for example, prohibit eating or smoking in the workplace.39 In

addition, many workers wear heavy gloves and/or use respiratory protection, both of which

would minimize hand-to-mouth transfer. The parameter Is was assigned a uniform distribution

of 0 – 0.02 g/h.

3.7 Dose Assessment of Recycling and Disposal of Steel Scrap

The exposure scenarios for the steel scrap analysis are based on the schematic flow diagram of

the recycling and/or disposal of steel scrap presented in Figure 3.1. These scenarios fall into six

general categories, corresponding to the six headings shown in boldface type in Table 3.10. The

table lists the full descriptive title and short name—or abbreviation—of each individual scenario,

the mixing factor for that scenario (as mentioned earlier), and which of the three principal

exposure pathways are addressed in the analysis of each scenario. A complete list of parameters

characterizing the various scenarios and their values and distributions is presented in Table B.8.

3.7.1 Handling and Processing Scenarios

After clearance of scrap metal from an NRC-licensed facility, scrap and the various products of

the melting and refining process (slag, dust, and metal products) would be handled and processed

in a number of settings. The handling and processing scenarios analyzed for the present analysis

encompass a range of representative activities.

Generic scenarios for industrial workers use a range of values that reflects varying operational

practices among scrap yards and melt shops. The duration of exposure is limited to the time that

a worker would reasonably spend working with or in close proximity to residually radioactive

material. Even though the exposed individual would be primarily engaged in handling scrap or

furnace products, for example, he is unlikely to spend each full workday exposed to such

materials. Other activities would include checking out equipment, driving equipment back and

forth between parking, storage, and handling areas, refueling equipment, waiting for vehicles to

load or unload, receiving instructions or plans for work to be done, and performing other duties. 

Therefore a range of daily exposure times that often did not span a full workday is assigned to

some scenarios to account for these other activities. 
Chapter 3 Recycling and Disposal of Steel Scrap

3-43 NUREG-1640

 Table 3.10 Scenario and exposure pathway matrix

Scenario abbreviation Scenario title MFa Pathwaysb

Extc Inh Ing

Handling and Processing

Scrap yard Processing steel scrap at scrap yard SD 1 ! !

Handling slag Handling slag at steel mill AA F1 ! !

Transferring EAF dust Transferring EAF dust at steel mill AA 4 ! !

Baghouse maintenance EAF Baghouse maintenance AA 10

Handling metal product Handling metal product at steel mill or foundry AA 5 ! !

Processing EAF dust Processing EAF dust DP 3 ! !

Processing steel slag Processing steel slag for road construction AA 2 ! !

Atmospheric Release

Airborne emissions Emission of airborne effluents from furnace AA F2 ! !

Transportation

Scrap truck–driver Truck driver hauling cleared steel scrap N 8

Slag truck–driver Truck driver hauling slag AA 9 ! !

EAF dust–bulk trailer Truck driver hauling EAF dust in dry bulk trailer AA 11

EAF dust–dump trailer Truck driver hauling EAF dust in dump trailer AA 12 ! !

Metal product–driver Truck driver hauling steel products AA 13

Product Use

Sailor–operations Sailor with watch station in operations area AA 19

Sailor–deck duty Sailor with watch station on deck AA 19

Building road with slag Building road using steel slag AA F1 ! !

Driving on slag road Driving on road built with steel slag AA F1

Slag basement Living in basement built with cement made from slag AA 7

Exposure to large mass Exposure to large metal mass SH 2

Exposure to small mass Exposure to small metal mass SH 3

Steel object on body Small steel object on body SH 6

Home with steel studs Living in home built with steel studs SH 15

Driver–automobile Driver of automobile with cast iron engine block SH 16

Driver–diesel engine Driver of truck with cast iron diesel engine block SH 17

Sailor–hull plate Sailor berthing near steel hull plate SH 18

Landfill Disposal

Scrap disposal–industrial Handling steel scrap at an industrial landfill IL F1

Scrap disposal–municipal Handling steel scrap at a municipal landfill ML F1

Dust disposal-industrial Handling BOF/foundry dust at an industrial landfill IL F1

Dust disposal-municipal Handling BOF/foundry dust at a municipal landfill ML F1

Slag disposal–industrial Handling slag at an industrial landfill IL F1 ! !

Slag disposal–municipal Handling slag at a municipal landfill ML F1 ! !

EAF dust disposal Handling EAF dust at a hazardous waste landfill HL F1

Groundwater Infiltrated by Leachate from Landfills or Storage Piles

Leachate–industrial–scrap Leachate from industrial landfill–scrap IL !

Leachate–municipal–scrap Leachate from municipal landfill–scrap ML !

Leachate–industrial–dust Leachate from industrial landfill—BOF/foundry dust IL !

Leachate–municipal–dust Leachate from municipal landfill—BOF/foundry dust ML !

Leachate–steel slag Leachate from slag storage pile AA !
Recycling and Disposal of Steel Scrap Chapter 3

NUREG-1640 3-44

Notes to Table 3.10

a MF = mixing factor (see text—additional details in Appendix D): AA = annual average, DP = EAF dust processing,

HL = hazardous waste landfill, IL = industrial landfill, ML = municipal landfill, N = no mixing, SD = scrap dealer,

SH = maximum single heat

b

 Ext = external, Inh = inhalation, Ing = ingestion

c External exposure dose coefficients (details in Appendix C):

1 Scrap pile

2 Slag pile

3 Dust pile

4 Baghouse

5 Large metal object

6 Small metal object

7 Small object next to body

8 Scrap truck

9 Slag truck

10 Worker atop dust truck

11 Dust in dry bulk trailer

12 Dust in dump trailer: (a) driver’s seat, (b) sleeper

13 Truck with I-beams

14 Cement basement

15 House with steel studs

16 Auto—cast iron engine block

17 Diesel truck: (a) driver’s seat, (b) sleeper

18 Hull plate: (a) bunk, (b) lounge area

19 Steel ship: (a) berthing, (b) mess and lounge, © operations, (d) deck

F1 Soil contaminated to an infinite depth (Eckerman and Ryman 1993)

F2 Contaminated ground surface (Eckerman and Ryman 1993)

3.7.1.1 Processing Steel Scrap at a Scrap Yard

Following clearance from an NRC-licensed facility, scrap metal would be transported to a scrap

yard, where it would be unloaded, processed, and prepared for shipment to a melter. The scrap

processing scenario describes the exposure of a scrap yard worker while shearing or torchcutting the metal, briquetting or crushing thin and lightweight materials, and baling. The daily

duration of external and internal exposure is assigned a range of 4 – 6 h, based on information

furnished to SC&A personnel during visits to two scrap yards processing ferrous metal scrap. 

This individual is assumed to work 250 days per year.

The source of external exposure is a 3,500-ton (3,175 t) pile of steel scrap, at an average distance

of 2 m from the worker. (The size is based on the sizes of ferrous metal scrap piles observed by

SC&A personnel during a visit to a large scrap yard.)

The airborne concentration of dust that is the source of inhalation exposure was modeled on the

basis of data collected by the U.S. Occupational Safety & Health Administration (OSHA) at the

site of the World Trade Center in New York. As described by OSHA (2002a):

OSHA has taken a total of 1331 samples (excluding bulk and blank samples) to monitor

worker exposures to dusts, fumes, oxides, and other compounds of metals such as antimony,
Chapter 3 Recycling and Disposal of Steel Scrap

3-45 NUREG-1640

3.10

beryllium, chromium, cobalt, copper, iron, lead, manganese, mercury, molybdenum, nickel,

vanadium, zinc, cadmium, magnesium, and arsenic. To minimize the length of the "WTC

OSHA Heavy Metal Monitoring Data tables" only the samples that showed detected results

for these metals are listed. 

Of particular interest to the present assessment are 515 measurements of iron oxide

concentrations based on samples collected by personal monitors worn by various workers

(OSHA 2002 b – 2002 e). Each sample spanned a period which appears to correspond to the

daily duration of exposure, ranging from 30 min to 9.5 h, with a mean duration of 5.84 h. 

Because the present radiological assessment assumes that all existing health and safety

regulations would be adhered to, we deleted 24 measurements that showed average daily

concentrations in excess of the OSHA limit of 10 mg/m3

, leaving a data base of 491 average

daily concentrations. Since the scrap yard worker is assumed to work 250 days a year, we

created a random sample of 250 of these concentrations. The average of these 250 values

represents an average annual concentration. This annual average was calculated 10,000

times—once for each realization of the scrap yard worker’s dose assessment.

The measurements of iron oxide reflect the fact that the iron or steel being processed oxidizes

upon being suspended as an aerosol. However, the residual radioactivity of such dust originates

in the metal. The iron oxide is assumed to be Fe2O3, which contains 69.94% Fe by weight. 

Consequently, in calculating the inhalation dose to the scrap yard worker, a factor of 0.6994 was

inserted into Equations 3.8 and 3.9 to adjust for the Fe content of the dust.

3.7.1.2 Handling Slag at Steel Mill

The exposed individual in the slag handling scenario is a worker at a steel mill who transfers slag

using a front-end loader. The slag is spread over a large, flat area—the vehicle is either on top or

at the edge of the pile. Because, as is discussed on page 3-42, this worker performs other duties,

as well as being away from the slag pile while transferring the load to a waiting transport

vehicle, the daily exposure duration is assigned a uniform distribution of 2 – 6 h. This individual

is assumed to work 250 days per year.

The dose from external exposure is calculated as follows:

Cig = average activity concentration of nuclide i in slag (Bq/g)

Fix = dose coefficient for external exposure to nuclide i (:Sv/h per Bq/g) 

from Federal Guidance Report (FGR) 12: soil contaminated to an infinite depth

(Eckerman and Ryman 1993)

Svx = vehicle shielding factor

The vehicle shielding factor, Svx, accounts for the shielding afforded by the loader. Based on

interviews with equipment manufacturers and landfill operators, a geometric model was
Recycling and Disposal of Steel Scrap Chapter 3

40 David Fellows, The Heil Co., Mid West Region, Delafield, WI, private communication with Robert Anigstein,

SC&A, Inc., September 15, 1993.

NUREG-1640 3-46

developed to characterize the effective shielding for operators of this type of large equipment. 

Based on calculated transmission factors, this parameter is assigned a triangular distribution with

a range of 0.3 – 0.7 and a mode of 0.5. 

The uncertainty factor, Ux, is used to account for different locations of the worker with respect to

the slag. If he is on top of the slag, he is exposed to an effectively infinite slab of slag, which

conforms to the exposure conditions modeled in FGR 12, so Ux = 1. When he is loading slag

from the edge of the large, flat pile, he is exposed to one-half of an infinite slab, so Ux = 0.5. 

Therefore, Ux is assigned a uniform distribution of 0.5 – 1.

The airborne concentration of the principal components of steel slags, such as those listed on

page 3-13, are subject to the same OSHA protective exposure limit (PEL) as nuisance dust,

which is 5 mg/m3 for respirable particles. Because the limit is a time-weighted average (TWA)

that applies to any given 8-hour shift, the annual average concentration would be significantly

less than this limit. In the present analysis, the annual average airborne dust concentration is

modeled as a truncated lognormal distribution, with a range of zero to 5 mg/m3

 and a mean of 2.5

mg/m3.

3.7.1.3 Transferring EAF Dust at Steel Mill

The EAF dust transfer scenario describes a steel mill worker transferring EAF dust from a

hopper underneath the baghouse to a dry-bulk trailer in preparation for shipment. The worker

stands on top of the trailer while the dust is being loaded via an overhead chute or conveyor belt.

External exposure is from the dust in the trailer, which is realistically modeled, based on

engineering drawings and other information from The Heil Co., the manufacturer of one of the

trailers known to be used for transporting EAF dust.40 Because some dust would become

airborne during this transfer, the dust concentration is modeled by the same distribution used in

the slag-handling scenario. 

The actual transfer takes from 30 minutes to one hour. The annual exposure duration depends on

the number of truckloads of dust generated by the steel mill in one year, which is calculated as

follows:

nL = number of truckloads required to haul away EAF dust generated in one year

Md = mass of dust generated by given steel mill in one year (t)

mL = mass of load (t)
Chapter 3 Recycling and Disposal of Steel Scrap

41 Rest periods necessitated by work in a confined area and the need to don and remove protective clothing restrict

the amount of time the worker can spend on this task.

3-47 NUREG-1640

3.11

The dose from external exposure is calculated by means of Equation 3.6, while that from internal

exposure by means of Equations 3.8 and 3.9, with

3.7.1.4 EAF Baghouse Maintenance

Steel mill workers are occasionally assigned to spend a day repairing or changing the baghouse

filters. Such a worker typically spends four to six hours41 in the midst of the suspended filters in

the dust-laden atmosphere of the baghouse, wearing a respirator equipped with a full facepiece. 

While performing such maintenance, the worker would be exposed to external radiation from the

residual dust that is retained in the filters after they are emptied. At a typical facility, this

procedure is carried out an average of seven times per year (Anigstein et al. 2001, Section 5.4.4). 

Because different workers may be assigned this task over the course of a year, the exposure may

take place as little as one day a year, or as much as 10 days a year if one worker is always

assigned this duty. (This work is sometimes performed by outside contractors—the same

individual might then visit the same mill several times a year). 

The use of the respirator, as well as SCBA and supplied air, as needed, precludes any significant

internal exposures, which are therefore not addressed in this scenario.

3.7.1.5 Handling Metal Product at Steel Mill or Foundry

The metal handling scenario addresses the potential exposure of an individual performing a

variety of tasks at a steel mill or foundry. Even though merely handling the metal products will

not generate airborne dust, other processing activities ongoing at the melt shop (melting, pouring

molten steel, water-cooling steel, etc.) would cause metal dust to be suspended in the air.

External exposure is to a 200-kg mass of metal at an average distance of 2 m. The airborne dust

concentration is modeled by the same distribution used in the slag-handling scenario described in

Section 3.7.1.2. Because the particulate matter would most likely be in the form of iron oxide, a

factor of 0.6994 was inserted into Equations 3.8 and 3.9 to adjust for the Fe content of the

material being inhaled or ingested. Due to the generic nature of the scenario, the exposure

duration has a range of 4 – 8 h/day.

3.7.1.6 Processing EAF Dust

The EAF dust processing scenario addresses a worker at a processing facility working near a pile

of EAF dust. The same scenario would represent workers at an HTMR facility (e.g., HRDC). 

The source of external exposure is an 8,000-ton (7.26 kt) pile of EAF dust, at an average distance

of 2 m. The size of the pile is estimated by assuming that the Envirosource facility in Ohio,

which has an annual capacity of 200,000 tons (180 kt), as noted in Section 3.2.4.1, would have a
Recycling and Disposal of Steel Scrap Chapter 3

NUREG-1640 3-48

backlog of about two weeks of material. The airborne dust concentration is modeled by the same

distribution used in the slag-handling scenario described in Section 3.7.1.2. The exposure

duration has a range of 2 – 6 h/d and occurs 250 d/y. 

A mixing factor specific to this scenario is described in Section 3.4.2.4.

3.7.1.7 Processing Steel Slag for Road Construction

The slag processing scenario addresses the exposure of a worker at a processing facility working

near a slag pile. The same types of activities that occur at a facility processing EAF dust would

occur here. The source material is limited to steel slags, since foundries usually do not generate

enough slag for commercial use to be economically viable.

The source of external exposure is a 20-kt pile of steel slag. The size, rounded to one significant

figure, is based on the requirements of the State of Ohio Department of Transportation (1998). 

To be acceptable for embankments, BOF slag must be aged for a minimum of six months, in

stockpiles that contain no more than 23 kt. (Ohio does not have a specification for EAF slag.) 

The airborne dust concentration is modeled by the same distribution used in the slag-handling

scenario described in Section 3.7.1.2. The exposure duration has a range of 2 – 6 h/d and occurs

250 d/y.

3.7.2 Emission of Airborne Effluents from Furnace

When cleared scrap is melted and refined, nearby residents would be potentially exposed to

airborne radioactive effluents released from the furnace. The airborne emissions scenario takes

place near a steel mill or foundry that is recycling scrap metal cleared from a nuclear facility. 

The exposed individual lives near the melt shop year round and his diet includes a certain

fraction of home-produced fruits, vegetables, milk and meat. 

This scenario includes the exposure pathways illustrated in Figure 3.3.

The airborne effluent emissions are either gaseous or are particulates that escape the air pollution

control system at the melt shop. Average air pollution control efficiencies range from 78% for

induction furnaces to 99.9% for EAFs. However, some smaller cupola furnaces, and most small

induction furnaces, do not employ APCDs (see Section 3.3.1.3).

To simplify the notation, the expressions for radioactive decay are not explicitly incorporated in

the expressions for radionuclide or activity concentrations in the following discussion of this

scenario. However, radioactive decay from the time of clearance is accounted for in the

calculations.
Chapter 3 Recycling and Disposal of Steel Scrap

3-49 NUREG-1640

Figure 3.3 Schematic diagram of airborne emissions scenario

3.12

3.7.2.1 Atmospheric Dispersion Term

The effluent emissions from the melt shop form a plume that undergoes dispersion due to the

turbulence of the atmosphere as it is transported downwind from the facility. The downwind

concentrations of such gaseous effluent emissions are usually estimated by means of one of

several Gaussian dispersion models. These concentrations are used to assess the exposures of

the nearby residents.

The sector-averaged Gaussian plume model assumes that within each sector the pollutant

concentration will not vary with the angular coordinate (i.e., the direction) of the receptor with

respect to the emission source. For a release rate that is steady during the course of a year, the

average concentration of a given atmospheric pollutant at a given distance from the emission

point in a given sector is calculated according to the following equation: 

= average radionuclide concentration at distance x in sector k (Bq/m3)

Q = radionuclide release rate (Bq/s)

fijk = joint frequency of Pasquill stability class j and wind speed i in sector k

he = effective release height (m)

)zj(x) = vertical standard deviation of plume for stability class j at distance x (m)

x = distance to receptor (m)

ui = mean speed of wind-speed range i in sector k (m/s)
Recycling and Disposal of Steel Scrap Chapter 3

42 Barry Parks, U.S. Department of Energy, private communication with Robert Anigstein, SC&A, Inc., April 10,

2002.

NUREG-1640 3-50

The ratio of the radionuclide concentration to the release rate is known as the sector-averaged

atmospheric dispersion factor, , or, more commonly, 3/Q.

An examination of the available STAR (STability ARray) data obtained from the Department of

Energy42 showed that complete data, including all seven atmospheric stability classes, were

available for only 54 locations in the contiguous 48 states. These data, comprising locations in

25 different states, are assumed to be representative of conditions nationwide. The methodology

for calculating dispersion factors in the present analysis is similar to that prescribed by the NRC

meteorology branch for licensees to follow in performing their own off-site impact analyses. 

This methodology is described in Regulatory Guide 1.111 (NRC 1977) and embodied in the

computer code XOQDOQ (Sagendorf et al. 1982). The analysis is designed to determine the

annual-average atmospheric dispersion factor (3/Q), as well as the annual-average ground

deposition factor (D/Q), for each wind sector at each of the above-mentioned 54 locations. 

This approach evaluates each of the 16 wind sectors and selects the sector where the atmospheric

and ground concentrations would be the highest on an annual-average basis. For each of these

16 sectors, the analysis used each of the 42 calculated 3/Q’s (6 windspeed classes × 7 stability

classes), weighted by the frequency of occurrence, to calculate the annual-average dispersion

factor for that sector. The exposed individual is assumed to live 1 km from the emission source

in the compass sector having the highest annual-average 3/Q for the given location. The 54 sets

of dispersion and deposition coefficients are then used to construct a probability distribution for

use with the Monte Carlo analysis of the scenario. 

Equation 3.12 applies if the release point is higher than twice the height of adjacent structures. 

Regulatory Guide 1.111, Regulatory Position 2. b, “Releases Other than Elevated,” states that

releases from points less than the height of adjacent buildings should be treated as ground-level

releases. For releases at an intermediate height (higher than adjacent structures, but less than

twice the height), detailed information regarding the exit velocity of the plume is required. If the

exit velocity is unknown, a ground level release is to be assumed. Since detailed information on

exit velocities that would be representative of the over 1,000 iron- and steelmaking facilities

covered by our analysis are not available, ground-level releases were assumed for the purpose of

these calculations. 

For ground level releases, the atmospheric dispersion factor is calculated as follows:
Chapter 3 Recycling and Disposal of Steel Scrap

3-51 NUREG-1640

3.13

(zj(x) = vertical standard deviation of plume at distance x, with correction for additional

dispersion within building wake cavity (m)

fD(x) = plume depletion factor at distance x

Dz = maximum adjacent building height either up- or downwind from release point

The algorithm for calculating the plume depletion factor is taken from a listing of the code

XOQDOQ (Sagendorf et al. 1982). At a distance of 1 km from a ground-level release, it has a

value of 0.9. This value can be confirmed by referring to Regulatory Guide 1.111 (NRC 1977,

Figure 3). 

Because of the variety of iron- and steelmaking facilities being modeled, Dz was assigned a

uniform distribution of 15 to 50 m. These values were assigned on the basis of personal

observations made during visits to several steel mills by SC&A staff members, an examination

of photographs taken during these visits, and engineering judgment. 

The methodology described above applies to gaseous releases. The concentrations of elemental

radioiodines and particulates are depleted by fallout as the plume travels from the release point

to the receptor location. This plume depletion effect is modeled by including the plume

depletion factor, fD(x), in Equation 3.13. For gaseous releases, fD(x) = 1.

3.7.2.2 Ground-Surface Concentration Resulting from Atmospheric Releases

The ground deposition rates of elemental radioiodines and particulates were calculated as a

function of distance, in a manner similar to that used for the 3/Q calculation described above. 

D(x) = deposition rate of radionuclide at distance x (Bq/(s$m2

)

fp(x) = relative deposition rate at distance x (m-1)
Recycling and Disposal of Steel Scrap Chapter 3

NUREG-1640 3-52

3.14

These ground deposition rates enable the calculation of annual-average areal concentrations of

deposited radionuclides. These concentrations also include the activity that is weathered off

plants. Therefore the total deposition rate was used in the calculation.

Cg(x) = ground-surface radionuclide concentration at distance x (Bq/m2

)

tb = period of long-term buildup of activity in soil (d)

 = radioactive decay constant (d-1)

The volumetric radionuclide concentration in the soil is calculated as follows:

Cs(0)(x) = soil radionuclide concentration at distance x at time of scenario (Bq/g)

d1 = thickness of surface soil layer (m)

's = average density of soil in surface layer (g/m3)

3.7.2.3 Concentration in Edible Parts of Plants

The radionuclide concentration in the edible parts of plants at the time of harvest is described by

Equation 3.14. This equation is used to calculate the concentration in leafy vegetables and

vegetables (for human consumption) due to direct deposition and root uptake. The concentration

of C-14 and H-3 in plants is calculated using Equations 3.15 and 3.16, respectively.

Cv = radionuclide concentration in edible part of plant v for consumption (i.e., leafy

vegetables and vegetables) due to root uptake and directly deposited material

(Bq/kg wet-weight plant)

r = the fraction of total material being deposited that is intercepted by crops
Chapter 3 Recycling and Disposal of Steel Scrap

3-53 NUREG-1640

3.15

3.16

e = effective weathering and decay constant at harvest (d-1)

= j + w

j = radioactive decay constant of nuclide j (d-1)

w = weathering constant (d-1)

tgv = time period that crops v are exposed to contamination during growing season (d)

Yv = yield of plant v (kg wet-weight plant/m2

)

Biv = root uptake factor for radionuclide i from soil to plant v (dimensionless)

P = areal soil density (kg/m2

)

The areal soil density (P) is the product of the bulk density of soil and the mixing depth of the

soil layer. The bulk density, 1.6 g/cm3, is taken from FGR 12 (Eckerman and Ryman 1993),

while the thickness of the soil layer is the plow depth: 0.15 m. Values for most environmental

and biotic transport of radionuclides were fixed and were taken from Kennedy and

Strenge (1992). 

The concentration of C-14 in plants is calculated as follows:

Cv,C-14 = concentration of C-14 in edible part of plant v (Bq/g wet-weight plant)

fv,C = fraction of total plant mass that is stable carbon

= 0.11

3C-14 = concentration of C-14 (as 14CO2) in air at receptor location (Bq/m3)

3C = concentration of stable carbon (as CO2) in the atmosphere

= 0.16 g/m3

The concentration of H-3 in plants due to airborne effluent emissions is calculated as follows:

Cv,H-3 = concentration of H-3 in edible part of plant v (Bq/g wet-weight plant)

= fraction of total plant mass that is water

= 0.75

rH-3 = ratio of tritium concentration in plant water to tritium concentration in

atmospheric water

= 0.5 

3H-3 = concentration of H-3 (as THO) in air at receptor location (Bq/m3)
Recycling and Disposal of Steel Scrap Chapter 3

NUREG-1640 3-54

H = absolute humidity of the atmosphere at receptor (g/m3)

Till and Meyer (1983) state that atmospheric humidity varies greatly from one location to

another in the United States. A map in that reference divides the continental United States into

five regions, each with a different range of absolute humidity. The values range from a low of

3.5 g/m3 in the Rocky Mountain region to a high of 16.2 g/m3 along the Gulf Coast (Till and

Meyer 1983, Figure 9.1). The areas of these five regions were used to derive a frequency

distribution of the mean absolute humidity in each region, which is listed in Table 3.11. 

Table 3.11 Absolute Humidity in Continental United States

Percentage of U.S. Average absolute humidity (g/m3

)

40% 4.9

20% 6.6

20% 8.4

15% 10.7

5% 13.8

Weighted average 7.3

A triangular distribution was assigned to this parameter, with a range of 3 g/m3

 to 16 g/m3 and a

mode of 7 g/m3

, based on the extreme values cited in Till and Meyer’s map, and the mean value

from the distribution in Table 3.11, rounded to one significant figure. 

Plants for human consumption are assumed to have a holdup period before being consumed. The

radionuclide concentration in plants at the end of the holdup period is calculated as follows:

Cv,h = radionuclide concentration in edible part of plant v for human consumption at the

end of the holdup period (Bq/g wet-weight plant)

 = radioactive decay constant (d-1)

th = holdup period between harvesting and consumption (d)

3.7.2.4 Dose Calculation

The source of external exposure is the surficial activity concentration on the soil as a result of

deposition from the plume. The exposed individual is assumed to spend certain amounts of time

indoors, outdoors, and at other locations away from the source of exposure. The dose from

external exposure is calculated as follows:
Chapter 3 Recycling and Disposal of Steel Scrap

3-55 NUREG-1640

Cis = areal activity concentration of nuclide i on ground surface (Bq/m2)

Fix = dose coefficient for external exposure to nuclide i on contaminated ground surface

(:Sv/h per Bq/g) (from FGR 12)

Ssx = indoor shielding factor

tid = time spent indoors during assessment period (h)

tod = time spent outdoors during assessment period (h)

Values for the parameter Ssx were developed from the values used in Kennedy and Strenge

(1992), because they represented reasonable values for a residence.

Doses from the inhalation of effluents in the passing plume and inhalation of suspended particles

of soil are calculated as follows: 

Aip = activity of nuclide i inhaled directly from passing plume during assessment period

(Bq)

Air = activity of nuclide i inhaled due to resuspension of soil during assessment period

(Bq)

The activity inhaled directly from the passing plume is calculated as follows:

Rhs = breathing rate for indoor activities (m3

/h)

Rso = ratio of indoor to outdoor radionuclide concentrations

Rhod = breathing rate for normal activities outdoors (m3

/h)

3i = average concentration of radionuclide i in ambient air from passing plume, from

Equation 3.12 (Bq/m3)

Rso is assigned a value of 0.40, based on Alzona et al. (1978), who estimated that the dust level

inside a building is about 40% of that outdoors—conditions within a plume are similar to those

resulting from suspended soil.

The activity inhaled as a result of resuspension of the soil at a residence is calculated by

Equation 3.17. A fraction of an individual's time at the residence will be spent indoors, during

which the individual will breathe dust blown in from outdoors as well as dust tracked inside,

then resuspended. During the fraction of the time spent outdoors, the individual's time will be
Recycling and Disposal of Steel Scrap Chapter 3

NUREG-1640 3-56

3.17

divided into time spent engaged in activities that could generate dust (such as sweeping, playing

sports, and gardening) and time spent engaged in other outdoor activities (such as walking,

sunbathing, and washing windows).

Rhdd = breathing rate for dusty activities outdoors (m3/h)

tdd = time spent on dusty activities outdoors (h)

3dd = concentration of resuspended soil in ambient air during dusty activities outdoors

(g/m3)

3do = concentration of resuspended soil during normal activities outdoors (g/m3)

3s = concentration of resuspended soil blown indoors (g/m3)

Fr = indoor resuspension factor (m-1)

Pd = indoor dust-loading on floors (g/m2)

Cis = ground surface concentration of radionuclide i (Bq/m2

)

's = average density of soil in surface layer (g/m3)

ds = thickness of soil layer available for resuspension (resuspension layer) (m)

The thickness of the soil layer that is available for suspension, ds, is used to calculate the ambient

radionuclide concentrations due to resuspension. The types of human activities that could cause

resuspension are walking or driving on packed dirt or roadways. A value of 1 cm (0.01 m) is

used for ds, based on the assumption that the particles that are deposited on the soil during an

atmospheric release would not be mixed deeper into the soil under normal conditions. 

Food pathways comprise plant products grown at the receptor location, milk produced by a cow

that consumes forage grown on the same location, meat from animals raised on site, and

secondary (inadvertent) ingestion of surface soil on site. The calculation of doses via this

pathway involves the following assumptions:

& The concentration of radionuclides in edible parts of the plant at the end of the first growing

period is used as the harvest concentration. Multiple harvesting of food crops and forage is

not included.

& The concentration of C-14 and H-3 in the edible parts of the plant due to atmospheric release

is calculated separately, using different equations.

& The harvested crops and animal products for human consumption are retained during a

holdup period before being consumed. Radioactive decay during the holdup period is

accounted for in the intake calculation.
Chapter 3 Recycling and Disposal of Steel Scrap

3-57 NUREG-1640

• Instantaneous equilibrium occurs between the radionuclide concentration in the soil and in

the concentration in the plants.

The dose from ingestion of contaminated plants and soil is calculated as follows:

fhv = home-produced fraction of all vegetables (dimensionless)

Cil = concentration of radionuclide i in edible part of leafy vegetables (Bq/kg wetweight) 

Ul

 = human consumption rate of leafy vegetables (kg/y wet-weight)

Civ = concentration of radionuclide i in edible part of non-leafy vegetables (Bq/kg wetweight) 

Uv = human consumption rate of non-leafy vegetables (kg/y wet-weight)

fhf = home-produced fraction of fruit (dimensionless)

Cif = concentration of radionuclide i in edible part of fruit (Bq/kg wet-weight) 

Uf = human consumption rate of fruit (kg/y wet-weight)

fhm = home-produced fraction of meat (dimensionless)

Cim = concentration of radionuclide i in meat (Bq/kg wet-weight) 

Um = human consumption rate of meat (kg/y wet-weight)

fhk = home-produced fraction of milk (dimensionless)

Cik = concentration of radionuclide i in milk (Bq/kg wet-weight) 

Uk = human consumption rate of milk (L/y)

Cis = concentration of radionuclide i in soil (Bq/g dry-weight soil)

Us = human consumption rate of soil (g dry-weight soil/y)

The total annual intakes of milk, meat, fruit, leafy vegetables and other vegetables were based on

data in the “Exposure Factors Handbook” (EPA 1997). The home-produced fraction of each of

these foods was represented by a triangular distribution constructed from data on different

population groups listed in EPA 1997. The lower limit of the distribution represents the average

“central city” resident, the mode represents “nonmetropolitan” populations, while the maximum

represents “households who farm.”

The soil ingestion pathway also includes uncertainty, incorporated in the modeling via the

parameter for consumption rate of soil, Us. The range used is based on an extensive recent

review of human ingestion of soil (Simon 1998). The lognormal distribution used in this
Recycling and Disposal of Steel Scrap Chapter 3

43 Eric Goldin, San Onofre Nuclear Generating Station, private communication with Kathleen Behling, SC&A, Inc.,

February 21, 2002.

NUREG-1640 3-58

analysis is adopted from Simon (1998), for “suburban lifestyles (with homes)—including lawns,

parks, recreational areas, some gardens.”

3.7.3 Transportation Scenarios

Several stages of the flow diagram depicted in Figure 3.1 involve transportation. Scrap metal

cleared from NRC-licensed facilities must be transported from a nuclear facility to the scrap yard

or landfill site, and the metal products and by-products must be transported from a melt shop to

manufacturers, processors, users, or disposal sites. Although these can occur by truck, rail, air

(for some highly specialized metal products), or waterway, truck transportation is ubiquitous for

most materials. Truck transportation also presents the highest potential doses to individuals

because of long exposure times and small distances between the material and the driver. The

potential critical group in each of the five transportation scenarios listed in Table 3.10 comprises

truck drivers hauling cleared steel scrap or the products or by-products of the melting and

refining of such scrap. 

3.7.3.1 Truck Driver Hauling Cleared Steel Scrap

This scenario describes the transportation of cleared scrap metal from the nuclear facility. As

described in Section 3.2, the scrap metal can either be transported to a scrap dealer if it is

destined for recycling, or to a waste disposal facility if the licensee or contractor so chooses. No

internal exposures of drivers from surficial or volumetric contamination of the scrap are

expected. According to a DOE handbook on airborne releases: No significant impacts [i.e.,

suspension] are anticipated for material that will undergo plastic deformation (e.g., metal,

plastics, wood) during free-fall or upon impact with a hard, unyielding surface (DOE 1994).

The external exposure is from a 20-t truckload of cleared scrap. The exposure duration is based

on information from the San Onofre Nuclear Generating Station (SONGS), which is currently

undergoing decommissioning. A representative of SONGS stated that when scrap haulers come

to the site, they arrive in a convoy of six to eight trucks, as opposed to one driver going back and

forth, to remove the materials. They take the scrap to a location that is about 1 to 11⁄2 hours from

the site.43 The analysis assumes that the same group of drivers would perform this work during

the course of a year. The number of hours of exposure per year is therefore calculated as

follows:

M0 = mass of steel scrap cleared in one year (t)

tt = time per trip (h)
Chapter 3 Recycling and Disposal of Steel Scrap

44 AMAD is the acronym for Activity Median Aerodynamic Diameter, "[which] is the diameter of a unit density

sphere with the same terminal settling velocity in air as that of an aerosol particle whose activity is the median of the

entire aerosol." (Eckerman et al. 1988). 

3-59 NUREG-1640

Nd = number of drivers

3.7.3.2 Truck Driver Hauling Slag

Slag is typically transported from a steel mill or foundry to a slag processor by drivers employed

by the processor. According to Kalyoncu (2002): “Most ferrous slag was transported less than

100 kilometers; trucks were the most economical means of transportation for such distances.” 

Because the slag is transported in open dump trucks or dump trailers and the driver is present to

operate the mechanism that unloads the trailer, internal exposures from airborne and deposited

slag dust would occur during the loading and unloading of the truck.

The external exposure is from the 20-t truckload of slag during the time the driver is in the cab of

the truck. 

The airborne concentrations of respirable dust during loading and unloading were calculated

from measurements of an EPA-sponsored study performed by the Midwest Research Institute

(MRI) (Bohn et al. 1978, Tables B-3 and B-4). MRI performed six measurements of airborne

dust concentrations generated by the load-out of processed slag into 35-ton (32-t) capacity dump

trucks using a 10 yd3

 (7.6 m3) front-end loader. The data included measurements taken both

upwind and downwind of the operation. Reported data included the total dust concentrations

and the fractions with AMAD < 30 :m and < 5 :m.44 In the present analysis, the concentrations

of particles with AMAD < 10 :m were calculated by first subtracting the upwind (background)

concentrations from the downwind measurements and then performing a log-log interpolation

between the 30 :m and 5 :m values. A lognormal distribution was then derived, based on the

mean and standard deviation of these results.

The hours of external exposure per year in driver’s seat are calculated as follows:

txyd = duration of external exposure in driver’s seat (h/y)

Mg = mass of slag generated in one year (t)

X = distance traveled (mi)

= average time in driver’s seat hauling one-way load (h/w)
Recycling and Disposal of Steel Scrap Chapter 3

45 Fletcher Hall, American Trucking Association, private communication with Kathleen Behling, SC&A, Inc.,

April 8, 2002.

NUREG-1640 3-60

= average time driving with one-way load (h/w)

v = average speed (mph)

tw = time in driver’s seat hauling one-way load (h/w)

The time in the driver’s seat is based on data on Type 2 (regional) drivers summarized in Table

3.12. 

Table 3.12 Weekly hours of Type 2 drivers

Average Minimum Maximum

On duty a 55 38 70

Driving a 49 30 65

In driver’s seat b 51 32.7 66.7

Hauling one-way loadc 26.5 17.7 34.2

a

 American Trucking Association 2000

b Estimated—see text

c One-way driving time is calculated by subtracting 1⁄2 of the time spent driving from the time in the driver’s seat.

We estimate the time spent in the driver’s seat on the basis of information from a representative

of the American Trucking Association.45 According to this source, examples of time behind the

wheel include sitting at weighing stations, inspection station (typically between state borders),

whether the driver loads or unloads his haul (meaning that if he does not help in the unloading,

he may wait in vehicle), completing his daily logbook, etc. As much as one-third or more of the

total "on-duty driving time" could be spent in the cab but not driving. 

The time spent in the driver’s seat is estimated by first subtracting the time spent driving from

the total on-duty time, then adding one-third of this difference to the driving time. These data

are assumed to represent averages over 52 weeks per year. The time spent in the driver’s seat is

estimated by first subtracting the time spent driving from the total on-duty time, then adding onethird of this difference to the driving time. 

The duration of internal exposure is calculated as follows:

tiy = duration of internal exposure (h/y)

nt = number of trips per year

tit = time spent loading and unloading (h/trip)
Chapter 3 Recycling and Disposal of Steel Scrap

3-61 NUREG-1640

The number of trips per year is calculated as follows:

tdw = time in driver’s seat hauling one-way load (h/w)

3.7.3.3 Transportation of EAF Dust

Three types of truck trailers are commonly used to transport EAF dust to a treatment and/or

disposal facility. Two of these are explicitly addressed in the present analysis.

• Dry bulk trailer, which is a fully enclosed container that is unloaded pneumatically. The

driver of the tractor hauling the trailer would not usually be exposed to any airborne or

deposited dust—the trailer would not normally be attached to the tractor during the transfer

of dust from the baghouse into the trailer. Therefore, only external exposure is included in

this scenario.

• Dump trucks or dump trailers—open conveyances covered with tarpaulins. In such cases,

drivers may be exposed to airborne or deposited dust during loading and unloading.

• Roll-off containers carried on truck-trailers. This scenario was not analyzed, since the

exposures to drivers of such vehicles would be similar to or be bounded by the dump trailer

scenario.

Drivers hauling EAF dust would work for a licensed hazardous waste hauler or disposal firm. It

is therefore plausible that some drivers would carry this material year-round. 

Truck Driver Hauling EAF Dust in a Dry Bulk Trailer

The external exposure of the driver is from the 20-t truckload of dust during transportation. The

exposure duration is calculated in the same way as in the case of the driver hauling slag:

Md = mass of EAF dust captured in the baghouse in one year (t)

Because of the limited number of treatment and disposal facilities for EAF baghouse dust, as

discussed in Section 3.2.4.1, such dust is likely to be transported over long distances. Therefore,
Recycling and Disposal of Steel Scrap Chapter 3

46 According to FMCSA 2000, these are long-haul drivers who “ . . . are away from their normal work reporting

location and home for more than three days at a time; in total, they are away from home for a large part of the year.”

47 Ray Turner, The David J. Joseph Company, private communication with Robert Anigstein, SC&A, Inc.,

February 28, 2001.

48 See Footnote 40 on page 3-46.

NUREG-1640 3-62

the drivers would fall into the “Type 1" category.46 The weekly hours of Type 1 drivers are

shown in Table 3.13.

The distance traveled is assigned a triangular distribution. The minimum distance—65 mi (~100

km)—is based on the transport of baghouse dust from a steel mill visited by SC&A staff

members to a nearby processing facility. The average distance—1,000 mi (~1,600 km), used as

the mode of the distribution—is based on information from a source in the steel recycling

industry.47 The maximum—2,000 mi (~3,200 km)—is based on the maximum likely driving

distance from a U.S. steel mill to a domestic processing or disposal facility.

Table 3.13 Weekly hours of Type 1 drivers

Average Minimum Maximum

On duty a 58 47 76

Driving a 52 38 67

In driver’s seat b 54 41 70

Hauling one-way loadc 28 22 36.5

a

 American Trucking Association 2000

b Estimated—see text

c One-way driving time is calculated by subtracting 1⁄2 of the time spent driving from the time in the driver’s seat.

Based on an engineering drawing of a tractor-trailer combination furnished by The Heil Co., a

manufacturer of dry bulk trailers, the tractor hauling the trailer is assumed to be equipped with a

day cab (i.e., no sleeping compartment).48

Truck Driver Hauling EAF Dust in a Dump Trailer

This scenario differs from the preceding one in two significant respects. First, the driver is

assumed to drive a truck equipped with a sleeping compartment. Second, he is assumed to

remain with his vehicle during loading and unloading, and to be exposed to airborne dust

generated during the transfer. 

The number of days of exposure in the sleeper is calculated as follows:
Chapter 3 Recycling and Disposal of Steel Scrap

3-63 NUREG-1640

t1ys = days of exposure per year in sleeper 

tmd = maximum permitted driving time without an 8-h rest period

= 10 h

The hours per night spent in the truck’s sleeper berth are based on a survey of long-distance

drivers commissioned by the Federal Highway Administration (FHWA 1999). These data,

which are listed in Table 3.14, were used to construct a cumulative distribution function for this

parameter.

Table 3.14 Hours spent in truck sleeper berth

Uniform range: 2 - 3 4 - 5 6 - 7 8 - 9 10 - 12

Number of drivers 1 11 97 183 14

Percent 0.33% 3.59% 31.70% 59.80% 4.58%

Source: FHWA (1999)

The airborne dust concentration during the loading and unloading of the dump truck is assigned

the same distribution as is used in the analysis of the driver hauling slag. The duration of

internal exposure is also calculated in the same manner as that of the slag hauler, with the

changes appropriate to the transportation of EAF dust (i.e., distances traveled, annual production

of by-product, etc.)

3.7.3.4 Truck Driver Hauling Steel Products

Drivers hauling heavy loads, such as steel I-beams, in mountainous terrain, such as the area

surrounding Pittsburgh, PA, are skilled and specialized in this work, and are likely to be

employed full time carrying such cargo. The only exposure pathway is external exposure to the

20-t load of steel products. The hours of external exposure per year are calculated as follows:

Mp = mass of metal produced in one year (t)
Recycling and Disposal of Steel Scrap Chapter 3

49 See Footnote 47 on page 3-62.

50 Technical staff, Carderock Division, Naval Surface Warfare Center, private communication with SC&A project

staff, January 30, 2003.

51 “Light tons” refers to the weight or displacement of the fully outfitted vessel, but without fuel or cargo.

NUREG-1640 3-64

The distance traveled is represented by a beta distribution, with a mean value (276 mi [444 km])

based on the average distance for shipment of “Base metal in primary or semifinished forms and

in finished basic shapes” (Bureau of the Census 1999). The minimum value is based on

engineering judgment—50 mi (~80 km) results in an average exposure time of 1 hour. Although

shorter trips are possible, the time spent loading and unloading would make it unlikely that a

driver would spend less than ~1 hour per load. The maximum distance is estimated to be 2,000

mi (3,200 km).49

3.7.4 Product Use Scenarios—Annual-Average Mixing

The first five product use scenarios listed in Table 3.10 involve large batches of material: steel

used to make the hull, decks, and bulkheads of a ship; and slag used in a roadbed or as an

ingredient in portland cement. The radiological assessments of the groups described by these

scenarios are based on annual average mixing of cleared scrap with materials from other sources. 

In the remaining seven product use scenarios, the assessments are based on the maximum singleheat mixing factors, as discussed in Section 3.4.2.2.

3.7.4.1 Steel Ships

Two scenarios listed in Table 3.10 address the exposures of sailors serving aboard a naval vessel. 

All of the steel plates on the ship are assumed to be made from steel produced in a

furnace—either a BOF or an EAF—that uses cleared scrap as part of its metal feed. This is a

plausible assumption, given that a shipyard normally contracts a single supplier for its steel

plates.50

There are a number of reasons for selecting these scenarios for the present analysis. One is that

the ship is a very large metal object that, as stated above, is likely to be made primarily of steel

produced at a single melt shop. Unlike the case with most other work-related scenarios, the ship

scenarios provide an opportunity for 24-hour per day exposures during most of the year. In

addition, there is an active shipbuilding industry in the United States. 

The last observation is based in part on the list of major shipbuilding contracts of U.S. shipyards

compiled by Colton & Company (1996). Out of a total of 302 vessels under contract at the end

of 1996, 146 had been ordered by U.S. Government agencies. The total tonnage of the vessels

ordered by the Government was listed as 928,692 light tons51 (842.5 kt). Since steel is the

preponderant material used in the construction of large vessels, this represents a small but

significant market segment for steel products. (The total tonnage of vessels under commercial
Chapter 3 Recycling and Disposal of Steel Scrap

3-65 NUREG-1640

contracts was not listed.) The Government vessels range in size from 55 2-ton surf boats ordered

by the Coast Guard, to two 75,000-ton aircraft carriers.

The assessment of these exposure scenarios is intended to encompass the range of exposures of

crew members of maritime vessels, both civilian and military, as well as of other individuals

occupying large metal structures. In the interest of a realistic analysis, however, we selected a

specific model ship with specific crew assignments and duties. The model is based on the U.S.

Navy AOE-6 (Supply) class fast combat support ship, the Navy’s largest combat logistics ship. 

However, the model is not intended to, and does not, exactly replicate the AOE-6 class.

AOE-6 class general characteristics (Sharpe 1999):

• Length . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 754 feet (230 m)

• Beam . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 107 feet (32.6 m)

• Displacement ............. 48,800 tons (44.3 kt) (full load); 19,700 tons (17.9 kt) (light)

• Crew . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40 officers, 627 enlisted

The scenarios assess the exposures of two individuals. They are both enlisted personnel who

sleep in a large berthing area just below the main deck and use the crew messing (dining) and

lounge areas on top of the main deck. One sailor stands watch in the operations area on the

fourth level in the forward superstructure, while the other is involved in underway replenishment

(UNREP) operations and stands watch on the main deck during such operations. While not

standing watch, both sailors are involved in maintenance and training in or near their respective

watch stations.

External exposures to both sailors are from the steel plates in the hull, decks, and bulkheads. 

Since there would be no significant abrasion of the steel during the time the sailors are aboard,

internal exposures are not addressed.

The exposure duration of all crew members is governed in part by the ship’s optempo—the

fraction of time the ship is at sea. For fiscal year 1997, the latest for which data are available,

the projected average optempo of all U.S. Naval vessels on active duty was 55% (Department of

the Navy 2001). The optempo in the present analysis is assigned a triangular distribution, with a

range of 45 – 65%, and a mean of 55%. Crewmen would take their annual leave while the ship

is in port. The time on leave is represented by a triangular distribution, with a range of 14 – 28

days and an average of 21 days.

Sailor with Watch Station in Operations Area

Area-average exposure rates are calculated for the four areas occupied by the operations

watchstander in this idealized model. Because the rate calculated by MCNP code already takes

into consideration the variation in position within each occupied area, the uncertainty parameter,

Ux, in Equation 3.7, is assigned a fixed value, Ux = 1. The sources of exposure in each of these

areas are approximately 30 separate parts of the hull, decks, and bulkheads which comprise the

structure of the ship. Machinery and steel frame members (girders, stanchions, and stringers)
Recycling and Disposal of Steel Scrap Chapter 3

52 See Section 1.6.1 for a description of the code.

NUREG-1640 3-66

would most likely not come from the same melt shop as the steel plates; therefore, they are not

assumed to be made from cleared scrap. The interior compartments contain cargo, fuel, engines,

furniture, bedding, etc., none of which are assumed to consist of cleared materials. As a

practical matter, photon radiation (x-rays and -rays) from all but the nearest components would

be considerably attenuated. Nevertheless, the model ship was analyzed as a single entity,

eliminating the need for subjective judgment as to which components to evaluate for which

receptor location, in light of the fact that the MCNP code52 models the contribution from

radiation scattered by air, water, and surrounding objects. 

This sailor would spend 72 hours per week in the main crew berthing area (sleeping, relaxing,

and performing housekeeping duties and personal functions) while the ship is at sea. He would

spend 66 hours per week in the operations area, 24 hours in the messing and lounge areas, and

six hours on the main deck for recreational purposes. While the ship is in port, except for the

days away from the ship on leave or in training, the sailor would spend part of his off-duty hours

ashore on liberty. However, he would sleep and take some of his meals aboard the ship. 

Because of the watch and duty cycle, it is convenient to distribute the time in port over a 28-day

period. During such a cycle, he would spend 248.5 hours in berthing, 56 hours in lounge and

mess, 189 hours in the operations area, and the rest of his time ashore.

Sailor with Watch Station on Deck

The UNREP watchstander would occupy three of the same locations as the operations

watchstander: berthing, mess and lounge, and the main deck, which is his watch and duty

station. Because of different duty assignments, the distribution of time at these locations is

somewhat different. He would spend 89 hours per week in the berthing area, 53 hours on the

main deck, and 26 hours in mess and lounge. In port, when not away on leave or training, he

would spend 252 hours per 28-day cycle in berthing, 179 hours on deck, 56 hours in mess and

lounge, and the remaining time on liberty.

3.7.4.2 Road Built with Steel Slag

Steel slag is used as road fill and may also be used as an aggregate in asphaltic cement used as

pavement. Two scenarios describe the exposures of individuals to slag used for this purpose. 

The first addresses the exposure of road construction workers, while the second addresses

motorists driving over such a road after it is completed. In both cases, slag constitutes the entire

road base as well as 80% of the pavement. 

Building Road Using Steel Slag

Road construction workers using steel slag as the underlayer of a roadbed would be subject to

external exposure to the slag, as well as being subject to internal exposure from slag dust. Since

such a worker would be exposed to a large expanse of a thick, flat layer of slag, the external
Chapter 3 Recycling and Disposal of Steel Scrap

3-67 NUREG-1640

3.18

exposure is modeled by means of the dose coefficients for soil contaminated to an infinite depth

from FGR 12 (Eckerman and Ryman 1993). 

The uncertainty factor, Ux, is used to account for different locations of the worker with respect to

the slag in the road base. If he is on top of the road base, away from the edges, he is exposed to

an effectively infinite slab of road base, which conforms to the exposure conditions modeled in

FGR 12, so Ux = 1. When he is at the edge of the road, he is exposed to one-half of an infinite

slab, so Ux = 0.5. Therefore, Ux is assigned a uniform distribution of 0.5 – 1.

The airborne concentration of slag dust is assigned the same distribution as in the slag-handling

scenario described in Section 3.7.1.2.

The exposure duration would depend on the amount of slag produced by a given furnace in one

year, and on the rate of road construction. (However, it is unlikely to exceed 250 days in one

year, the period of assessment in the present analysis.) R.S. Means 2000, a standard reference

for contractors, states that a road construction crew laying down a 1-foot-deep (30-cm)

pavement base of 11⁄2-inch diameter (4-cm) crushed stone has a production rate of 3,800 yd2

(3,177 m2) per day. A crew laying down 4-inch-thick (10-cm) asphaltic concrete has a rate of

4,140 yd2

 (3,462 m2) per day. Assuming that the same crew lays down both the pavement base

and concrete, the area of road produced in a day can be determined as follows:

= Rate of road production (m2/d)

Rb = Production rate of road base

= 3,177 m2

/d

rb = fraction of day spent laying down road base 

Rc = Production rate of concrete pavement

= 3,462 m2

/d 

Solving the second Equation 3.18 for rb, we find

Substituting this expression in the first Equation 3.18, we obtain
Recycling and Disposal of Steel Scrap Chapter 3

53 A description of a representative position is found in “Road Maintenance Worker” (2000).

NUREG-1640 3-68

The quantity of slag used per day can now be readily determined:

= rate of slag utilization

= 1,279 t/d

dc = thickness of concrete

= 0.102 m

fc = fraction of slag in asphaltic concrete

= 0.8

db = thickness of road base

= 0.305 m

'g = bulk density of slag

= 2 g/cm3

The exposure duration is calculated as follows:

tys = exposure duration (d/y)

Mg = total mass of steel slag (EAF or BOF) generated in one year (t)

As depicted in this scenario, the workers also perform other duties, such as maintenance of

equipment and training. It is very unlikely for any worker to spend all of his 8-hour shift

exposed to the slag in the road base. However, it is likely that he would spend over one-half of

his time so employed.53 Consequently, the exposure duration is assigned a uniform distribution

of 5 – 7 h/d.

Driving on Road Built with Steel Slag

The second of the slag road scenarios addresses the exposure of a commuter driving over the

road constructed in the previous scenario. In the completed road, the source of exposure is the

pavement, which is made of asphaltic concrete containing 80% slag which was used as

aggregate. Although the layer underlying the pavement is assumed to be made entirely of slag,

any direct radiation from this layer would be strongly attenuated by the pavement and would not

make a significant contribution to the external exposure of the motorist.
Chapter 3 Recycling and Disposal of Steel Scrap

3-69 NUREG-1640

Since the slag is either contained within or under a solid mass, no slag dust would be dispersed

into the air while the driver is on the road, thus eliminating the source of internal exposure. 

The exposure duration is based, in part, on EPA 1997, Table 15-121, which lists a distribution of

time spent traveling in a car per 24-hour period. The percentiles for all respondents are shown in

Table 3.15, below.

Table 3.15 Time spent traveling in a car (min/d)

%-ile 0 5 25 50 75 90 95 98 99 100

Time 1 10 34 63 110 175 240 345 450 1280

Source: EPA 1997, Table 15-121

The exposure duration is also a function of the length of the segment of the road that can be built

with one year’s production of slag:

L = length of road built from one year’s slag production of EAF or BOF (m)

a = area of road built from one year’s slag production of EAF or BOF (m2

)

w = width of typical U.S. highway

= 2 lane × 12 ft wide (FHWA 2001)

= 7.315 m

Assuming that a person commutes to and from work on the same stretch of road, 250 days per

year,

txs = exposure duration (h/d)

v = average travel speed driving to work

= 33.6 mph (data for 1995 [NPTS 1997, Figure 11])

= 5.41 × 104

 m/h

tc = time spent in car (see Table 3.15) (min/d) 

The dose from external exposure to direct radiation from residual activity in the slag is

calculated as follows:
Recycling and Disposal of Steel Scrap Chapter 3

54 Jamie Rogers, Texas Industries, Inc., private communication with William C. Thurber, SC&A, Inc., April, 1997. 

55 As was mentioned on page 3-6, steel slags are not suitable for use as aggregate in concrete used in construction.

NUREG-1640 3-70

3.19

Cig = concentration of nuclide i in slag (uncorrected for decay) (Bq/g)

fg = fraction of slag in concrete

Fix = FGR 12 dose coefficient for nuclide i in soil contaminated to infinite depth (:Sv/h

per Bq/g)

tys = exposure duration (d)

3.7.4.3 Living in Basement Built with Cement Made from Slag

Texas Industries, Inc. (TXI) holds a patent on the CemStar process, which uses 5% to 15% steel

slag in producing the clinker that goes into portland cement.54 Cement, in turn, constitutes 10%

of concrete, the remaining ingredients being aggregate (80%), water, and sand. Assuming that

the average amount of slag in cement made with this material is 10%, the resulting concrete

would have an average slag content of 1%.

If slag generated at a steel mill recycling cleared scrap was used in producing portland cement,

and if that cement in turn was used to make concrete for constructing the floor and outside walls

of a basement, a person occupying that basement would be subject to external exposure to

residual radioactivity of the slag.55 The exposed individual in this scenario spends variable

amounts of time each day in such a basement. Since the walls and floor would be covered and/or

painted, there would be no particulate matter generated from the concrete. Consequently, there

would be no opportunity for internal exposure via inhalation or ingestion. 

The exposure duration is modeled as a triangular distribution, with a range of 4 – 16 h/d and a

mode of 16 h/d. The lower end of this range was chosen to encompass work-related occupancy

of a concrete structure. A most likely value was chosen to represent a residential setting; this

was also used as the maximum value in the parameter range. The exposure takes place 350 days

per year. The dose is calculated by Equation 3.19, using the parameters appropriate to the

present scenario.

3.7.5 Product Use Scenarios—Maximum Single-Heat Mixing Factor

In seven product use scenarios, the assessments are based on the maximum single-heat mixing

factors, as discussed in Section 3.4.2.2. In each case, since the source of exposure is an iron or

steel product in domestic or commercial use, the only pathway is external exposure to the object
Chapter 3 Recycling and Disposal of Steel Scrap

3-71 NUREG-1640

in question. Since there would be no release of residually radioactive material from the object,

there would be no opportunity for internal exposure.

The first three of these scenarios portray exposures to generic metal objects. These generic

representations describe groups of similar exposure situations (e.g., individuals close to a large

mass of metal or a small mass of metal close to the body), rather than specific scenarios (e.g., a

person wearing a belt buckle or using a frying pan). The scenario "exposure to large metal

mass," for example, represents such exposure situations as individuals using large consumer

products (e.g., a refrigerator) made from recycled steel scrap.

These scenarios incorporate uncertainty into exposure duration via the parameter for hours per

day, while the value for days per year is held constant. Exposure times for the generic large and

small metal mass scenarios were developed to include those individuals who spend a large

fraction of their workday or residential time near these objects (e.g., machine tools, office

furniture, and household appliances or furniture). The daily exposure durations are represented

by a triangular distribution with a range of 2 – 8 h and a mode of 4 h. The exposures occur 350

days per year. The most likely value is one-half of a typical workday. A range of 2 – 8 h/d

would cover a variety of potential exposure situations in both residential and occupational

settings.

The other four scenarios depict realistic exposures to specific products. Although some

simplification of these models is necessary, these assessments are as realistic as practicable

within the scope of the present analysis.

3.7.5.1 Exposure to Large Metal Mass

The large metal mass scenario assesses the external exposure to a large generic object that is

constructed of iron or steel made from recycled steel scrap. The source of exposure is a 200-kg

hollow metal cylinder at an average distance of 2 m. 

3.7.5.2 Exposure to Small Metal Mass

The small metal mass scenario assesses the external exposure to a small generic object that is

constructed of iron or steel made from recycled steel scrap. This generic object represents a

wide range of small to medium-sized home appliances. The source of exposure is a 12-kg

hollow metal sphere at an average distance of 2 m.

3.7.5.3 Small Steel Object on Body

The small steel object scenario assesses the external exposure to a small generic steel object that

is worn or carried in close contact with the body. It has a mass of 45 g and can represent a wide

variety of objects: pendants or other pieces of large jewelry, belt buckles, pocket knives, etc. 

The exposure duration is represented by a triangular distribution with a range of 2.86 – 16 h/d

and a mode of 5 h/d. The exposures occur 350 days per year. The exposure duration has a wide

range because of the variety of potential sources of exposure. 
Recycling and Disposal of Steel Scrap Chapter 3

56 The high price of taxi medallions, which are required to operate a “yellow cab,” one that is licensed to pick up

passengers on the street and at airports, etc., mandates that the owner would maximize his income.

57 Allan Fromberg, Assistant Commissioner for Public Affairs, New York City Taxi & Limousine Commission,

private communication with Robert Anigstein, SC&A, Inc., March 19, 1998.

NUREG-1640 3-72

3.7.5.4 Living in Home Built with Steel Studs

Steel framing components are commonly used in home construction—the American Iron and

Steel Institute (AISI 1998, Chapter 4) estimated that the number of full-steel home starts in the

United States has doubled from 40,000 in 1994 to 95,000 in 1997 and was projected to reach

325,000 by the year 2000. 

The exposure geometry depicts an individual inside a small house in which the conventional 2-

by-4 wood frame is replaced by steel studs. It is plausible that such a house would be

constructed with steel components made from a single roll of sheet metal, which was rolled from

a bloom cast from a single furnace heat. 

The exposure duration is represented by a triangular distribution with a range of 4 – 16 h/d, and a

mode of 8 h/d. The exposures occur 350 days per year. The range of exposure durations is

designed to encompass both residential and work-related exposures. 

3.7.5.5 Driver of Automobile with Cast Iron Engine Block

The automotive industry is a large consumer of steel made from recycled scrap—approximately

32% of a typical U.S. automobile is made from recycled steel (SRI 2001). In the exposure

assessment of the driver of an automobile, it is assumed that one component is made from the

single furnace heat with the largest likely fraction of cleared scrap. The most massive object that

could be made from a single furnace heat is a cast iron engine block, which is the source of

external exposure in this scenario. 

The exposed individual is the owner/operator of a taxicab. The exposure duration is based on

the rules that govern the working hours of such individuals and on their actual work practices. 

Such rules are exemplified by the regulations of the Taxi and Limousine Commission of the City

of New York, which stipulate that an owner/driver must work a minimum number of 9 hours per

day for 210 days per year before he is allowed to lease his cab to another driver.56 This provides

an estimate of the lower limit of the annual exposure duration. The upper limit is based on the

regulatory limit of 12 hours of driving in any 24-hour period—the driver is assumed to take a

one-half hour break during each day, reducing his daily exposure to 11.5 hours. He might work

as much as six days a week, 50 weeks a year, for a total of 300 days.57 The exposure duration is

assigned a uniform distribution spanning this range of hours per year. 
Chapter 3 Recycling and Disposal of Steel Scrap

58 The U.S. Department of Transportation defines Class 8 trucks as those with a gross vehicle weight (GVW)—

including cargo—greater than 30,000 lb (~13.6 t). 

3-73 NUREG-1640

3.7.5.6 Driver of Truck with Cast Iron Diesel Engine Block

The diesel engine scenario is intended to represent exposures to large pieces of industrial

equipment made of cast iron. The selected component is a cast iron diesel engine block on a

Class 8 truck58 used for long distance hauling. This scenario encompasses other exposure

scenarios where the source material is cast iron. The exposed individual is the owner-operator of

such a truck. Hence, he would be driving the same truck for an entire year and, in addition to

time spent on duty in the driver’s seat, would spend additional time in the sleeping compartment. 

Although there are other possible scenarios where the source term would be an even more

massive cast iron component, the greater distance between the exposed individual and the

source, and the shorter average annual exposure duration, would most likely lead to smaller

exposures. Furthermore, the truck driver represents a sufficiently large number of individuals to

fall within the scope of the present analysis.

The exposure duration in the driver’s seat is based on the weekly hours of Type 1 drivers listed

in Table 3.13. These data are assumed to represent averages over 52 weeks per year. The hours

per night in the sleeper are the same as those of the truck driver hauling EAF dust in a dump

trailer, described on page 3-63. The number of days of exposure in the sleeper is calculated as

follows:

t1dw = time in driver’s seat (h/week)

3.7.5.7 Sailor Berthing near Steel Hull Plate

Because sailors spend considerable periods of time aboard ship and may be assigned sleeping

quarters which are located immediately adjacent to the ship’s hull, the exposure of a sailor to a

hull plate made from cleared scrap was selected to represent exposures to large steel plates. 

Although the sailor might be an enlisted man on a naval vessel or a member of the merchant

marine, the former was selected for the present analysis.

This scenario differs from the steel ship scenarios described in Section 3.7.4.1 in that the

exposure is to a single hull plate made from the single furnace heat having the maximum likely

fraction of cleared scrap. Separate exposure geometries are defined for the sailor occupying his

bunk and for being in the adjacent lounge area. The exposure duration in both locations is based

on information on practices of the U.S. Navy; however, since this scenario is intended to span

the range of exposures on a variety of vessels, both military and civilian, the exposure duration is

more generic than in the scenarios described in Section 3.7.4.1.
Recycling and Disposal of Steel Scrap Chapter 3

59 Cdr. John Harrop, USN (ret.), private communication with Robert Anigstein, SC&A, Inc., February 2002.

60 A description of a representative position is found in “Landfill Equipment Operator” (2002).

NUREG-1640 3-74

According to the Department of the Navy (1998, p. C-3), naval enlisted personnel afloat in

wartime have 87 hours off duty per week, including 56 hours allotted to sleeping. According to

a former naval officer,59 the maximum time per week a sailor would spend in his bunk would

comprise 56 hours sleeping, three hours Sunday free time, and one-half of the 14 hours per week

allotted to "free time," for a total of 66 hours per week, or an average of 9.4 hours per day. At a

minimum, a sailor would sleep seven hours per night and spend the rest of his free time away

from his bunk. In addition, a sailor would spend from 1⁄2 to 11⁄2 hours of his free time in the

lounge area. Uniform distributions spanning the cited ranges were assigned to the daily

occupancy of the two locations.

A sailor might spend as much as six months of a year away from his ship, which includes

training and leaves, leaving six months on board. At a minimum, a sailor will be away on leave

for 30 days, leaving 335 days on board. A most likely scenario is 300 days per year on board

ship. A triangular distribution, with these three values comprising the minimum, maximum and

mode, was assigned to the days per year during which exposures would occur.

3.7.6 Landfill Disposal Worker Scenarios

Scrap metal and by-products of melting and refining may be disposed of in a landfill. Landfills

used for waste disposal include industrial or construction and demolition (C&D) landfills, MSW

landfills, and hazardous waste landfills. MSW landfills, except for previously existing landfills

operating under a “grandfather” exemption, are regulated under RCRA Subpart D. Industrial

and C&D landfills may comply with Subpart D regulations, but EPA does not require them to do

so. (In the present report, the term “industrial landfill” includes C&D landfills.) Except for

different annual volumes of waste—industrial landfills are typically (but not always) smaller

than MSW landfills—these two landfill categories are treated the same way in the analysis. (The

waste streams affect the mixing factors for these scenarios.)

Hazardous waste landfills fall under RCRA Subpart C. According to current practices, as

discussed in Section 3.2.4.1, EAF dust placed in a Subpart C landfill is stabilized and placed in

drums or other containers prior to disposal. 

Seven scenarios assess the exposures of workers at landfills. As depicted in these scenarios, the

workers operate equipment on top of the landfill and are exposed to the materials being disposed

of. Their activities can include moving the waste with a front-end loader using a piece of

machinery, such as a bulldozer, to compact the material in the landfill. These workers also

perform other duties, such as maintenance of equipment and training and administrative

functions. It is very unlikely for any worker to spend all of his 8-hour shift exposed to the waste. 

However, it is likely that he would spend over one-half of his time so employed.60
Chapter 3 Recycling and Disposal of Steel Scrap

3-75 NUREG-1640

Consequently, the exposure duration is assigned a uniform distribution of 5 – 7 h/d, and occurs

during 250 days per year.

In all seven cases, external exposure is assessed in the same manner as in the slag handling

scenario described in Section 3.7.1.2. In the present cases, however, the individual is not

assumed to spend a significant amount of time at the edge of the landfill. Consequently, the

exposure geometry resembles that of the semi-infinite slab, so the uncertainty parameter in

Equation 3.6 has a fixed value, Ux / 1. 

3.7.6.1 Handling Steel Scrap at an Industrial or MSW Landfill

Because no mechanical cutting or shredding of cleared scrap metal is assumed to occur prior to

disposal, it is reasonable to assume that there would be no appreciable release of residually

radioactive particulate matter from the scrap, and consequently no mechanism for internal

exposure of landfill workers disposing of such scrap. (See the discussion of the scrap

transportation scenario in Section 3.7.3.1). Therefore, the only exposure pathway is the external

exposure to the scrap deposited in the landfill.

3.7.6.2 Handling BOF or Foundry Dust at an Industrial or an MSW Landfill

As described in Section 3.2.3.1, the offgas from a BOF that is captured by an APCD is turned

into a sludge or “filter cake.” Although, in the present study, we apply the generic term “dust” to

all material that is captured by an APCD, in the case of the BOFs, such material would retain

enough moisture to prevent the formation of any significant amount of airborne particulate

matter. Consequently, there would be little opportunity for internal exposure of workers

disposing of this material in a landfill. The internal exposure to radionuclides in foundry dust

would be bounded by the internal exposure in the EAF dust processing scenario, and is not

separately assessed in this scenario. The only pathway that is assessed in this scenario is

external exposure to the dust deposited in the landfill.

3.7.6.3 Handling Slag at an Industrial or an MSW Landfill

Unlike scrap metal and BOF dust, slag would be likely to generate airborne dust as it is being

deposited in a landfill, giving rise to internal exposure pathways, which are included in the

assessment of this scenario. The concentration of airborne dust is represented by the same

distribution as is adopted for the slag handling scenario described in Section 3.7.1.2.

3.7.6.4 Handling EAF Dust at a Hazardous Waste Landfill

Since EAF baghouse dust would be stabilized and packed in containers prior to disposal in a

hazardous waste landfill, there would be no opportunity for internal exposure of the landfill

workers. The only pathway that is assessed in this scenario is external exposure to the dust

deposited in the landfill. A mixing factor specific to this scenario is described in Section 3.4.2.4.
Recycling and Disposal of Steel Scrap Chapter 3

NUREG-1640 3-76

3.7.7 Consumption of Groundwater Infiltrated by Leachate

Leachate from industrial or MSW landfills, or from a slag storage pile, could infiltrate nearby

wells used as sources of drinking water. Assessments are performed of the exposures of

individuals that obtain their drinking water from wells that are down gradient from landfills used

to dispose of cleared scrap, or BOF or foundry dust. These individuals are characterized by four

exposure scenarios, according to the disposed material and the type of landfill: (1) cleared scrap

disposed of in an industrial landfill, (2) scrap disposed of in an MSW landfill, (3) BOF and

foundry dust disposed of in an industrial landfill, and (4) the same dust disposed of in an MSW

landfill. A fifth scenario characterizes an individual drinking from a well that is down gradient

from a pile of stored slag.

The only pathway addressed by these scenarios is the consumption of drinking water from the

contaminated well. The only other plausible pathways—the use of well water in the production

of homegrown foods—would not have a significant impact on the dose. According to

EPA 1997, Table 13-71, homegrown produce accounts for less than 10% of the fruits and

vegetables consumed in the United States, and even smaller fractions of other foods. A scoping

analysis using an earlier version of the RESRAD computer program code (ANL 1996) showed

that doses from the groundwater pathway were dominated by the consumption of drinking water,

the consumption of foods produced on site making a negligible contribution.

3.7.7.1 Leachate from Landfills Used for the Disposal of Steel Scrap or BOF/Foundry Dust

Leaching of residual activities on cleared scrap, or in BOF or foundry dust, could begin

immediately after the metal or dust is emplaced in an industrial or MSW landfill. The leaching

of the activities and their subsequent transport through the soil underlying the landfill to an

aquifer and then to a nearby well used to supply household water is based on the model

underlying the RESRAD computer code, described by Yu et al. (2001). Although the RESRAD

model addresses the transport of radionuclides to a well either in or on the boundary of the

contaminated zone, Yu et al. (1993, Appendix K) also describe a simple methodology for

estimating off-site doses, which is used in the present analysis. The mathematical description of

the model used to calculate the leaching of the activities from the landfill is presented below.

The values assigned to the parameters used with this model are presented in Table 3.16, which

follows the description of the model.

Because of the time required for transport of radionuclides to an underground source of drinking

water, the maximum dose could occur many years after the emplacement of the wastes,

depending on the radionuclide in question and on the hydrogeology of the site. The present

analysis limits the period of assessment to 1,000 years from the time of release.

Travel Time Through the Vadose (Unsaturated) Zone

The travel time through the vadose (unsaturated) zone of the i-th chemical element was

determined by means of Equation E.21 of Yu et al. 2001:
Chapter 3 Recycling and Disposal of Steel Scrap

3-77 NUREG-1640

3.20

3.21

= travel time of i-th element through the vadose zone (y)

z = thickness of vadose zone (m)

= retardation factor of i-th element (in vadose zone)

pev = effective porosity of vadose zone

Rs = saturation ratio

I = infiltration rate (m/y)

'v = bulk soil density of vadose zone (g/cm3)

 = soil-water distribution coefficient for i-th element in vadose zone (cm3/g)

ptv = total porosity of vadose zone

Ksv = saturated hydraulic conductivity of vadose zone (m/y)

b = soil-specific exponential parameter

In the subsequent discussion, the subscript i has been dropped to simplify the notation. 

The fractional leach rate is calculated by Equation 3.21, which is based on Equation E.3 of Yu et

al. 2001.

: = fractional leach rate (y-1)

dL = thickness of contaminated zone (m)

The subscript “c” refers to the contaminated zone (i.e., landfill). The parameters ptc, Rdc, and Rsc

are analogous to the corresponding parameters ptv, Rdv, and Rsv of the vadose zone.

The concentration in the pore water percolating through the soil is given by:
Recycling and Disposal of Steel Scrap Chapter 3

NUREG-1640 3-78

3.22

3.23

Cp(t) = concentration of nuclide in pore water at time t (Bq/cm3

)

Co = initial specific activity of nuclide in landfill (Bq/g)

t = time from clearance (y)

ts = time of emplacement of wastes (= time scenario begins)

Transport to Well

Yu et al. (2001) present a simple model that describes the transport of the radionuclides through

the soil to the aquifer and thence to a drinking-water well down gradient from the source. The

transport of the activities from the surface to the aquifer is described above. Once the

contaminated water reaches the aquifer, it moves along a trajectory which is described by a

vector sum of the vertical flow rate (the infiltration rate) and the horizontal flow rate. Figure 3.4

shows how the contaminated water moving downward through a volume element of width dx, at

a distance x from the well, is deflected in the horizontal direction until it intercepts the well. 

The travel time in the aquifer is represented by

ta(x) = travel time of nuclide i through a distance x (y)

x = distance from source element to well (m)

J = hydraulic gradient

The subscript “a” refers to the aquifer. These parameters are analogous to the corresponding

parameters of the vadose zone.

Dilution of the pore water is modeled by Equation 3.24, derived by differentiating the first of

Equations E.27 of Yu et al. 2001:
Chapter 3 Recycling and Disposal of Steel Scrap

3-79 NUREG-1640

Figure 3.4 Transport of Leachate from Landfill to Well

3.24

3.25

df = incremental dilution factor (concentration in pore water ÷ concentration in well) of

element dx


w = screened depth of well (m)

The contribution of element dx to the concentration of a nuclide in the well water is given by the

following expression:

dCw(-) = increment of concentration of nuclide in well at time - (Bq/cm3

)
Recycling and Disposal of Steel Scrap Chapter 3

NUREG-1640 3-80

 (to  t  to + ta(l)) 3.26

 (t  to + ta(l)) 3.27

- = t – to – ta(!) (y)

 0

to = ta(xo) + tv + ts (y)

xo = distance from landfill boundary to well (m)

ta(!) = travel time in aquifer of nuclide through length ! (y)

! = x – xo (m)

The first of Equations 3.25 follows directly from the definition of df given above, while the

second was derived by substituting the expressions in Equations 3.22 and 3.24 for Cp(t) and df,

respectively. Differentiating the first line of Equation 3.23 with respect to x, and solving for dx,

At a fixed time t, 0- = – dta. Substituting these expressions in Equation 3.25, we obtain

The concentration of nuclide in well at time t is obtained by integrating the above expression

over the range of travel times in the aquifer, and introducing radioactive decay, which has been

omitted up to now for the sake of clarity:

At later times,
Chapter 3 Recycling and Disposal of Steel Scrap

3-81 NUREG-1640

3.28

A = active area of landfill (m2)

=

Mw = annual mass flow of waste (t/y)

Tw = time period for emplacement of wastes

= 1.7 y

Uw = pumping rate of well (m3

/y)

ta(l) = travel time in aquifer of nuclide through length l (y)

l = lo (m)



lo = length of landfill parallel to aquifer flow (m)

The concentration will increase with time as more and more of the leachate from the further

portions of the landfill reaches the well. For short-lived radionuclides, however, the increase is

offset by radioactive decay. The time of maximum concentration (in the absence of progeny

ingrowth) can be found by setting the derivative of Cw(t) to 0.

Solving Equation 3.28,

tm = time of maximum concentration from clearance (y)

 1,000 y

In the case of radionuclides with radioactive progenies, an iterative process is required to find

the time of peak dose, which is delivered by both the parent nuclide and by the progeny that has

grown in during the travel time from the contaminated zone to the well. To simplify the

expression, progeny ingrowth is not shown in Equations 3.26 and 3.27. Such ingrowth is

explicitly modeled by use of the Bateman Equations, as described in Appendix E.
Recycling and Disposal of Steel Scrap Chapter 3

NUREG-1640 3-82

Dose Assessment

The dose from drinking water from the well is calculated as follows:

Diw = Dose from drinking water from well during year of peak dose (:Sv/y)

= average concentration of radionuclide i in well during peak year (Bq/cm3)

Iw = annual consumption of water (cm3/y)

The radionuclide concentrations in the well water are calculated according to Equations 3.26 and

3.27. The consumption rate of tap water, Iw, was assigned a truncated lognormal distribution,

based on data in EPA 1997. The logarithmic mean and standard deviation are taken from EPA

1997, Table 3-11. The upper bound of the distribution is based on the maximum reported value

of 4,730 cm3

/d, while the lower bound is 196 cm3/d. The latter value was calculated by

assuming that the logarithms would be symmetrically distributed about the mean of 963 cm3

/d.

Landfill Parameters

The primary source of parameter values for the landfill groundwater scenarios is an EPA report

that lists input parameters to be used in groundwater modeling for the evaluation of industrial

landfills (EPA 2001c). These values, along with additional data sources, are listed in Table 3.16.

3.7.7.2 Leachate from Slag Storage Pile 

Similar to the leaching of residual activities from materials emplaced in a landfill, residually

radioactive constituents of steel slag in a storage pile could leach and infiltrate a drinking-water

well that is down gradient from the pile. A study, based on a search of available literature, was

performed to enable the calculation of leach rates of various radionuclides. In addition, EPA

sponsored an experimental study at the Brookhaven National Laboratory (BNL) to determine the

leach rates of constituents of various steel and iron slags. Details of these studies are presented

by Anigstein et al. (2001, Appendix I). Some of the information obtained from both studies is

presented in this section, followed by the development of a model of the leaching of

radionuclides which partition to the slag.
Chapter 3 Recycling and Disposal of Steel Scrap

3-83 NUREG-1640

Table 3.16 Landfill parameters

Symbol Units Source

Contaminated zone

Infiltration Rate (single liner) I m/y EPA 2001c

Depth dL m EPA 2001c

Waste density 'w g/cm3 EPA 2001c

Density of zone 'c g/cm3 fw 'w + (1 - fw 'v)

 a

Fraction of waste in landfill volume fw — Dehmel et al. 1994

Total porosity ptc — = ptv

Hydraulic conductivity Ksc m/y = 5 Ksv

b

Soil-specific exponential parameter bc — values for sand (Yu et al. 2000, Attachment C, p. 3-16)

Soil-water distribution coefficient Kdc cm3/g = 0.2 Kdv

c

Length parallel to aquifer flow lo m

Area A m2 calculated

Vadose zone

Saturated hydraulic conductivity Ksv m/y EPA 2001c

Total porosity ptv — EPA 2001c

Thickness zv m EPA 2001c

Bulk density 'v g/cm3 EPA 2001c

Soil-water distribution coefficient Kdv cm3

/g Yu et al. (2000, Attachment C, pp. 3-30/31) d

Soil-specific exponential parameter bv — = bc

Effective porosity pev — generic soil type (Yu et al. 2000, Attachment C, p. 3-9)

Aquifer

Effective porosity pea — EPA 2001c

Bulk density 'a g/cm3 EPA 2001c

Saturated hydraulic conductivity Ksa m/y EPA 2001c

Hydraulic gradient J — EPA 2001c

Depth of well below water table dw m EPA 2001c

Soil-water distribution coefficient Kda cm3

/g = Kdv

Total porosity pta — Yu et al. (2000, Attachment C, p. 3-6) value for sand

Well pumping rate Uw m3/a

Minimum = RESRAD default value (Yu et al. 2001)

Maximum (rounded) from Yu et al. (2000, Attachment C, p. 3-39)

Distance to well xo m EPA 2001c

a

 Assumes uniform mixing of waste with daily soil cover

b , assume Ksw >> Ksv

c Kdc = fw Kdw + (1 - fw) Kdv, assume Kdw << Kdv

d

 See Appendix B for additional data sources
Recycling and Disposal of Steel Scrap Chapter 3

NUREG-1640 3-84

3.29

3.30

Slag Cement Leaching Studies

The American Nuclear Society has developed and formalized detailed procedures for measuring

the leachability of solidified low-level radioactive wastes (ANS 1986). This procedure involves

testing of controlled-geometry specimens in demineralized water at 17.5°C to 27.5°C to

determine releases over successive intervals of time. Mass transport is assumed to be controlled

by a diffusion process. When the fraction leached from a uniform sample is less than 20% of the

initial activity, the leaching behavior can be approximated by that of a semi-infinite medium

where the "effective diffusivity" is given by the following equation:

Di = effective diffusivity of nuclide i (cm2

/d)

Tn = mean time of the leaching interval n (d)

=

ain = activity of nuclide i released during time interval n (Bq)

V = sample volume (cm3)

Aio = initial activity of nuclide i in sample (Bq)

nt = duration of n-th leaching interval (d)

= tn– tn-1

S = surface area of sample (cm2)

When the cumulative fraction leached, , is greater than 0.2, Equation 3.29 must be

corrected for specimen geometry. 

Using a model and procedures similar to those described in ANS 1986, Japanese investigators

have determined the fractional leaching of Sr-90, Co-60, Cs-137, and H-3 from cement/slag

composites in deionized water and synthetic sea water (Matsuzuru and Ito 1977; Matsuzuru et al.

1977, 1979). The duration of the leaching tests was about 100 days. The radionuclides were

incorporated into the cement via a sodium sulfate solution. Leaching data were analyzed using a

plane source diffusion model to derive the expression:
Chapter 3 Recycling and Disposal of Steel Scrap

3-85 NUREG-1640

3.31

3.32

3.33

3.34

fi

 = fraction of nuclide i leached in t days. 

Equation 3.30 can be rewritten as

where the expression in the square brackets is represented by mi

, the slope of the line obtained by

plotting fi vs. t

1⁄2. 

Once mi is determined, Equations 3.31 can be solved for Di:

Since the actual leaching process involves an initial rapid leaching rate of a few days' duration

(~ 7 d for Sr-90 and ~ 2 d for Co-60), followed by a longer-term linear relation between fi and t1⁄2,

the experimental data are fitted to an equation of the form 

Equation 3-30 can also be used to determine the value of fi for various geometries, as follows:

where subscripts 1 and 2 refer to geometries 1 and 2, respectively.

Because of certain limitations and problems, such as the initial leach rate, Matsuzuru and Ito

(1977) defined L, the leaching coefficient, with the same mathematical form as D in

Equation 3.32. Values of L for Sr-90 leached from slag cements ranged from 1.2 × 10-7 to

1.7 × 10-7 cm2

/day for both deionized water and synthetic sea water at 25°C. Using average

values of LSr for samples cured for seven days prior to testing in deionized water, and assuming a

right circular cylinder, h = 2r, V = 70 cm3

, we have derived values for mSr and Sr in

Equation 3.33, which are listed in Table 3.17. The leachability of Cs-137 was reported to be

about ten times that of Sr-90; it is therefore assumed that mCs = 10 mSr and Cs = 10 Sr. 

Equation 3.34 is then used to derive values that describe leaching from slag particles that are also

right circular cylinders, but only 1 cm in diameter—a more typical size for EAF slags. The

chromium data is based on particles that passed through a 9.5 mm mesh. The calculated value
Recycling and Disposal of Steel Scrap Chapter 3

NUREG-1640 3-86

(h = 2r) 

cited in the section “Other Slag Leaching Studies,” below, therefore constitutes an upper bound

to mCr for a 1-cm right circular cylinder, listed in Table 3.17.

 Table 3.17 Leaching parameter values

Element m (d-1⁄2) 

r = 2.233 cma r = 0.5 cm r = 2.233 cm r = 0.5 cm

Sr 5.8e-04 2.59e-03 4.97e-03 2.22e-02

Cs 5.8e-03 2.59e-02 4.97e-02 2.22e-01

Crb c 6.9e-06 0 0

a Corresponds to 70 cm3

 right circular cylinder ( h = 2r)

b Cr is used as a surrogate for Nb, Np, Pa and U—see discussion below.

c Not applicable, see text.

The strontium data are replaced by the data obtained from BNL, described below. 

Data from Brookhaven National Laboratory

Results from leaching experiments on EAF slags performed at BNL indicate that the leaching of

strontium was governed by diffusion (Fuhrmann and Schoonen 1997). The diffusion coefficients

determined from tests on three monolithic samples of EAF slag are listed in Table 3.18. To

calculate the value of mSr for a monolithic cylinder, we first invert Equation 3.32:

mSr = 1.54 × 10-2 d-1⁄2

DSr = 1.51 × 10-11 cm2/s (mean of values in Table 3.18)

= 1.30 × 10-6 cm2

/d

r = 0.5 cm

 Table 3.18 Diffusion coefficients for EAF slag monolithic samples

Slag Sample Diffusion Coefficient (cm2

/s)

AS-1 1.4e-11

AS-2 2.5e-11

AS-3 6.2e-12

Source: Anigstein et al. 2001 (Appendix I-1)
Chapter 3 Recycling and Disposal of Steel Scrap

61 Rick West, Sales Manager for International Mill Services, private communication with William C. Thurber,

SC&A, Inc., August 22, 1996.

3-87 NUREG-1640

Since Fuhrmann and Schoonen did not report any initial releases that were not diffusioncontrolled, Sr is set equal to zero. These data are used to model the Sr-90 leaching from the slag

in the present analysis.

Other Slag Leaching Studies

Researchers at Australia's Commonwealth Scientific and Industrial Research Organisation

incorporated the toxic elements As, Sb, Cd, Zn and Cr into slags of various types by melting

them at 1300°C, and subsequently leached the slags according to the EPA TCLP protocol

(Jahanshahi et al. 1994). Three of the slags, while not identical to EAF slags, are useful for

developing preliminary modeling parameters. Unfortunately, of the five elements studied, only

Cr is expected to be found in the slag in any significant quantity. However, in the absence of

element-specific leaching data, Cr can be considered as a surrogate for the stable oxides

expected in slags. Assuming that the fraction leached is proportional to t1⁄2, this fraction can be

expressed by Equation 3.33, where the upper limit of mCr is about 6.9 × 10-6 d-1⁄2, based on Cr in

the one of the slags tested. 

Leach Rate

The leach rate from slag is calculated by Equation 3.33, using the BNL data for strontium and

the parameter values for 1-cm diameter particles listed in Table 3.17 for other elements. 

Information from a slag processor indicates that the processor may size and stockpile slag over

six warm-weather months for winter use such as anti-skid road sanding.61 As mentioned in

Section 3.7.1.7, the State of Ohio Department of Transportation (1998) requires that slag used

for embankments must be aged for a minimum of six months in stockpiles that contain no more

than 23,000 t. The slag is thus assumed to have a turnover rate of twice a year and to contain six

months’ of slag production from a given steel mill, but not more than 23,000 t. The slag is

assumed to be continuously dumped onto a 1-meter high pile and to be removed at the same rate. 

The new slag is mixed uniformly with the old slag—the slag that is removed is thus a

representative sample of this mixture. 

To model the age-dependent leach rate, we must first determine the age distribution of the

individual particles in the pile. If there is a constant number, N, of particles in the pile, the

number of particles added or removed during time dt is

r = removal rate constant
Recycling and Disposal of Steel Scrap Chapter 3

NUREG-1640 3-88

3.35

(0 < t  T) 3.36

Assume that o particles are added to the pile at some initial time (t = 0). After time t, the

number of these particles left in the pile is given by

By definition, this is the number of particles older than t. The number of particles with ages

between t and t + dt is obtained by differentiating the above expression with respect to t and

changing the sign:

Since this expression is independent of the initial time, it can be generalized to all the particles in

the pile:

dn = number of particles in pile with ages between t and t+dt

N = total number of particles in pile

The time-dependent leach rate is derived by differentiating fi

 in Equation 3.33 with respect to

time: 

Multiplying the above expression by the age distribution function of Equation 3.35 yields the

leach rate of particles with ages between t and t + dt. Integrating that expression with respect to

time yields

= leach rate of nuclide i in slag pile at time t

t = time since the first residually radioactive slag was placed in pile

- = variable of integration

T = period during which pile receives residually radioactive steel slag

The integral expression does not have an analytical solution but must be evaluated numerically.

Equation 3.36 applies to the period during which the storage pile receives residually radioactive

slag. After this time, no new contaminated particles are being added to the pile. The general
Chapter 3 Recycling and Disposal of Steel Scrap

3-89 NUREG-1640

(t > T) 3.37

3.38

3.39

relationship remains the same, but the leaching is now from particles with ages between t and

t - T. 

The elapsed time since the pile began receiving residually radioactive slag is represented by t,

which is thus the age of the oldest radioactive particle in the pile, while t – T is the time since the

pile stopped receiving such slag, and thus the age of the newest particle.

The expression for the radionuclide concentration in the pore water percolating through the soil

(in the absence of radioactive decay) is analogous to that for the landfill scenario in

Equation 3.25:

Cip(t) = concentration of nuclide i in pore water at time t (Bq/cm3)

Cig = initial specific activity of nuclide i in slag (Bq/g)

dg = thickness of slag layer (m)

'g = density of slag (g/cm3)

The contribution of element dx to the concentration of radionuclide i in the well is given by the

following expression:

where all the parameters have been defined previously.

The first of Equations 3.39 follows directly from the definition of df following Equation 3.24, the

second was derived by substituting the expressions in Equations 3.38 and 3.24 for Cip(t) and df,

respectively, while the third was derived by differentiating the first line of Equation 3.23, solving

for dx, and substituting. The concentration of radionuclide i in the well at time - is obtained by

integrating the last line of Equation 3.39 and introducing radioactive decay, which has been

omitted up to now for the sake of clarity:
Recycling and Disposal of Steel Scrap Chapter 3

NUREG-1640 3-90

3.40

t1 = 0 ( to  t  to + (l))

t1 = t – to – (l) ( t > to + (l))

fU = dilution factor for water usage

=  1

A = area of slag pile (m2)

=

Vg = slag volume (m3)

= 



ms = one year's slag production (t)

mp = maximum mass of slag pile (t)

As was the case with the landfill scenarios, the concentration will increase with time as more and

more of the leachate from the further portions of the slag pile reaches the well. For short-lived

nuclides, however, the increase is again offset by radioactive decay. An iterative process is

required to find the time of peak dose, which is delivered by both the parent nuclide and any

radioactive progenies that have grown in during the travel time from the slag pile to the well.

The dose from drinking water from the well is calculated in the same way as in the landfill

leachate scenarios, described on page 3-82. The radionuclide concentration in the well water is

calculated according to Equation 3.40.

3.7.8 Scenario Timing

This section presents the basic assumptions used in defining the time periods for each of the

recycling scenarios. The timing is based on data on the U.S. ferrous metals industries,

supplemented by engineering judgment.
Chapter 3 Recycling and Disposal of Steel Scrap

62 Michael A. Mattia, Director, Risk Management, Institute for Scrap Recycling Industries, private communication

with Kathleen Behling, SC&A, Inc., October 19, 2001.

63 Gordon Geiger, College of Engineering and Mines, University of Arizona, Tucson AZ, private communication

with William C. Thurber, SC&A, Inc., September 17, 2001.

3-91 NUREG-1640

3.7.8.1 Scrap Transportation

• The scrap transportation scenario occurs two to six days after the scrap is cleared. This

includes time to schedule a truck, perform minimal sizing operations, bring the truck to the

site, load the truck, and ship the scrap to a scrap dealer or landfill.

3.7.8.2 Scrap Yard

• The scrap yard scenario begins two days after the scrap is loaded on the truck, allowing time

for transport, unloading, and conveying the scrap to the processing location in the scrap yard. 

Typically, steel scrap is shredded or size-reduced and shipped out within one week.62

Adding this time period to that of the transportation scenario, and allowing a minimum of

one day for the actual transport of the scrap, the processing of a particular batch of scrap

could begin as early as three days after the scrap is cleared and might occur as late as 17 days

after clearance.

3.7.8.3 Melting and Refining, and Processing

• A former steel industry executive noted that the amount of time that scrap metal would be

held at a steel mill will vary, based on scrap metal prices and business conditions, but that an

EAF shop might keep three weeks of inventory on hand.63 For a BOF shop, the scrap might

be on hand for about two weeks. (BOF shops tend to use more factory bundles of scrap,

which are typically auctioned monthly.) In either case, the melt shop’s objective is to keep

its raw materials inventory to a minimum. If continuous cast ingot from an EAF is rolled for

inventory rather than to order, the product might remain at the mill an average of two weeks

before being shipped. An exception could be large structural members, where setup time for

the rolling mill might dictate producing greater amounts of material during a run. The

inventory of some structurals might exceed four weeks. (Structurals are typically produced

by EAF shops rather than BOF shops.) On the other hand, for customers such as General

Motors, with a strong commitment to just-in-time (JIT) inventories, material may ship the

same day as it is rolled. (Typically, the automotive companies use sheet steel produced from

BOFs.) 

Another source of inventory information is visits to steel mills made by SC&A staff in 1996. 

One EAF shop purchased all of its steel scrap through one broker and generally used a JIT

approach. Trucks and rail cars provided pre-identified grades of scrap to facilitate furnace

charging. Rail cars were processed in two or three days. Truck shipments might remain on
Recycling and Disposal of Steel Scrap Chapter 3

64 Capt. A. Mancini, U.S. Naval Sea Systems Command, private communication with John Harrop, SC&A, Inc.,

May 19, 1999.

NUREG-1640 3-92

site for up to one month. The facility also had a large off-site scrap storage area where steel

purchased in response to low scrap prices was stockpiled for longer periods.

Based on this information, it is assumed that scrap steel remains at an EAF shop for zero to

30 days before it is melted. Comparable values for a BOF shop are zero to 14 days. The

semi-finished steel is assumed to remain for zero to 14 days at a BOF shop and zero to 28

days at an EAF shop. Cast iron producers are assumed to have schedules similar to those of

EAFs.

• Releases of airborne effluent emissions from a steel mill occur at the time the scrap is meltrefined (see above).

• Following initial processing, iron and steel products undergo further processing before use;

this secondary processing, plus storage and handling, is assumed to take 22 days.

3.7.8.4 Use of Iron and Steel Products

• Distribution of generic manufactured items is assumed to take seven days; distribution of an

automobile is assumed to take seven to 90 days.

• Generic manufactured items (i.e., large metal mass, small metal mass, small metal object

worn on the body) are assumed to be put into use immediately after distribution. 

• Construction of a simple house made with steel studs is assumed to take three to six months

after distribution.

• Shipyards generally procure steel plate as needed, and do not stockpile large quantities. 

Thus, the storage time in a yard is short, on the order of days. A naval supply ship may take

18 months from keel laying to delivery. Steel plate is used almost immediately, but since the

ship is built from the keel up, a few months may pass before the steel plate to be used in a

berthing compartment arrives at the shipyard.64

Once delivered, the crew will man the ship, and begin living on the ship. However, a

shakedown period of several months is typically required before the ship is in a full

operational status. Thus, the steel plates will be formed (poured and rolled) about 18 months

before the sailor begins berthing in the berthing compartment (Anigstein et al. 2001,

Appendix H-2).

The three scenarios involving sailors on ships are assumed to begin 18 months after the steel

is produced at an EAF or a BOF shop.
Chapter 3 Recycling and Disposal of Steel Scrap

3-93 NUREG-1640

3.7.8.5 Slag Use and Disposal

• Steel slag and baghouse dust are produced at the time melting and refining occurs.

• Steel slag that is sold for subsequent use is processed at the mill 2 – 4 days after it is

generated and leaves the mill in another 2 days. Slag is assumed to be used six months after

distribution. Slag that is to be disposed of in a landfill is held at the mill for 7 days, at which

time it is transported to a disposal facility. The slag is assumed to be disposed of

immediately following handling at a sanitary landfill.

• A road constructed with steel slag is open for use one day after the end of construction

activities.

3.7.8.6 Dust Processing and Disposal

• EAF baghouse dust is transported within three days after production. Handling and

processing of the dust takes four days, at which time the dust is disposed of in a hazardous

waste landfill. 

• BOF dust is sent to a landfill seven days after it is produced. Storage and handling take four

days, at which time the dust is disposed of in a landfill.

3.8 Calculation of Surficial Normalized Doses 

In most cases, the residual activity of the cleared scrap would reside on or near the surface. 

However, the radiation exposure of an individual to large batches of this material, which would

consist of many individual components of differing sizes and shapes, can be approximated by

assuming an average uniform distribution of the activity in the entire mass of the metal. All of

the scenarios discussed in this chapter treat the residual activities as distributed throughout the

mass of scrap or furnace product. Thus, whether the radiation source is a pile of assorted scrap,

or the residually radioactive metal products or non-metallic by-products of the melting and

refining process, expressing the radionuclide concentrations as specific activities, in Bq/g, is

more meaningful in the present analysis. 

Specific activities are related to areal activity concentrations by the following relationship:

Cij = specific activity of nuclide i in component j (Bq/g)

Sij = areal activity concentration of nuclide i in component j (Bq/cm2)
Recycling and Disposal of Steel Scrap Chapter 3

NUREG-1640 3-94

)j = mass-to-surface ratio of component j (g/cm2)

=

mj = mass of component j (g)

aj = exposed surface area of component j (cm2

)

A mass-based normalized dose is defined as the dose to an exposed individual, normalized to a

unit specific activity of a given radionuclide in the scrap at the time of clearance. This specific

activity is an average value: the total activity of a given nuclide divided by the total mass of

scrap being cleared. The exposure of this individual may be to scrap or to any of the products or

by-products generated during the recycling of the scrap—the normalized dose expressed is in

terms of the specific activity of the cleared scrap.

The surficial normalized dose is the dose to an individual exposed under the same conditions

from a radionuclide that was uniformly distributed over one surface of the scrap at the time of

clearance. This is likewise an average value: the total activity of a given nuclide divided by the

exposed surface area of scrap being cleared. For scrap that is in the form of sheets, plates, or

piping, it is assumed that the residual activity resided on only one surface. A surficial

normalized dose for each scenario is derived by dividing the mass-based normalized dose by the

mass thickness (mass-to-surface ratio) of steel scrap likely to be cleared from BWR or PWR

commercial nuclear power plants undergoing dismantlement.

Di(s) = surficial normalized dose from radionuclide i

Di(m) = mass-based normalized dose from radionuclide i

= average mass-to-surface ratio of carbon steel components likely to be cleared from

a BWR or PWR (g/cm2)

3.8.1 Mass-to-Surface Ratio

The mass-to-surface ratios of the various steel components of nuclear power reactors are

evaluated in order to create a frequency distribution for use in calculating the surficial

normalized doses. This evaluation, which is discussed in greater detail in Section A.6.1, consists

of examining the steel components of the Reference BWR and the Reference PWR. Three

general types of BWR components—rebar, structural steel, and pipe hangers—are judged to be

likely candidates for clearance. Each of these types comprises components which span a wide

range of sizes. Each size has a different mass-to-surface ratio. Four types of PWR

components—the three BWR types plus piping—are judged to be candidates for clearance. The

average mass-to-surface ratio of cleared steel components was calculated as follows: 
Chapter 3 Recycling and Disposal of Steel Scrap

65 As discussed in Chapter 1, the group which receives the highest mean normalized EDE from a given radionuclide

is defined as the EDE-critical group for that nuclide.

3-95 NUREG-1640

Since the mix of cleared components will vary over the 1.7-year period of dismantlement,

probability distributions of average mass-to-surface ratios of scrap cleared during a 12-month

period were constructed for both PWRs and BWRs. These values, specific to the reactor type

randomly selected during the Monte Carlo probabilistic analyses, were used to calculate the

surficial normalized doses.

3.9 Dose Assessments of Recycling and Disposal of Steel Scrap

As discussed in previous sections of this chapter, the radiological assessment of the clearance of

steel scrap from NRC-licensed facilities compares the radiation exposures of various groups to

each of 115 radionuclides and their progenies in 30 exposure scenarios. The exposures of

additional groups are assessed in seven scenarios involving exposures to iron and steel products

made from the single furnace heat during one year that contains the maximum fraction of cleared

scrap. These groups are not included in the ranking to determine the critical group for each

radionuclide.

3.9.1 Calculation of Effective Dose Equivalents (EDEs)

The groups described by nine of these scenarios receive the highest mean normalized EDEs from

one year of exposure to cleared steel scrap from all 115 nuclides, one scenario constituting the

EDE-critical group for 41 nuclides.65 Table 3.21 lists the mean and the 5th, 50th, and 95th

percentile mass-based normalized EDEs from each radionuclide to its respective critical group,

while Table 3.22 lists the corresponding surficial EDEs. Figure 3.5 lists the scenarios describing

the EDE-critical groups and displays the number of radionuclides for which each scenario

constitutes the critical group. The mean and the 5th, 50th, 90th, and 95th percentile normalized

EDEs from all 115 nuclides for all 30 scenarios are tabulated in Appendix F-1. The

corresponding statistics for the seven single-heat scenarios are tabulated in Appendix M-1.

The scenario giving rise to a critical group for the greatest number of radionuclides models

workers handling and processing scrap metal at a scrap yard. There are several reasons for this. 

First, the scenario occurs during the first two weeks following clearance. Consequently, a shortlived radionuclide such as P-32, with a 14-day half-life, would not have undergone a great

amount of decay. Second, this scenario occurs prior to the scrap being melted and refined;

therefore, none of the residual radioactive contaminants would have been removed by

partitioning or volatilization, as could happen once the scrap is melted. Finally, the scrap yard

workers spend much of their workday in close proximity to large quantities of scrap, and are
Recycling and Disposal of Steel Scrap Chapter 3

NUREG-1640 3-96

Figure 3.5 Scenarios giving rise to EDE-critical groups for steel

exposed to direct, penetrating radiation from -emitting nuclides, as well as to the inhalation and

secondary ingestion of the metallic oxide dust generated during the cutting and sizing operations.

In the case of the drinking water scenarios, many realizations of the Monte Carlo uncertainty

analyses result in zero doses from some radionuclides. Depending on the particular set of

parameters sampled, the contaminant could miss the well entirely or fail to reach it within 1,000

years or within 20 half-lives of the radionuclide in question, whichever is the shorter time. For

the six radionuclides listed in Table 3.19, the mean normalized EDE in the critical group is

higher than the 90th percentile EDE. The critical group for five of these nuclides comprises

individuals drinking water from wells down gradient from an industrial landfill containing

cleared steel scrap. The critical group for the sixth nuclide—Sr-90—comprises individuals

drinking water from wells down gradient from a slag storage pile. The group with the highest

EDE for which the mean does not exceed the 90th percentile might be considered as an alternate

critical group for that nuclide. These potential alternate critical groups are listed in Table 3.19.

3.9.2 Calculation of Effective Doses

The groups described by the same nine scenarios characterizing the EDE-critical groups receive

the highest mean normalized effective doses from one year of exposure to cleared steel scrap

from all 115 nuclides, the workers handling and processing steel scrap at a scrap yard

constituting the critical group for 59 nuclides. Table 3.23 lists the mean and the 5th, 50th, and

95th percentile mass-based normalized effective doses from each radionuclide to its respective

critical group, while Table 3.24 lists the corresponding surficial effective doses. Figure 3.6 lists

the scenarios describing the effective dose-critical groups and displays the number of

radionuclides for which each scenario constitutes the critical group. The mean and the 5th, 50th,
Chapter 3 Recycling and Disposal of Steel Scrap

3-97 NUREG-1640

90th, and 95th percentile normalized effective doses from all 115 nuclides for all 30 scenarios

are tabulated in Appendix F-2. The factors leading to the highest effective doses in these

scenarios are similar to those giving rise to the EDE-critical groups discussed in Section 3.9.1.

Table 3.19 Normalized mass-based EDEs from selected nuclides (:Sv/y per Bq/g)

Nuclidea Critical group Potential alternate critical groupb

Mean 90th %-ile Scenario Mean 90th %-ile Scenario

C-14 3.2e-02 0.0e+00 Leachate–industrial–scrap 1.1e-03 3.1e-03 Scrap yard

Mn-53 8.8e-04 0.0e+00 Leachate–industrial–scrap 8.4e-05 2.2e-04 Scrap yard

Sr-90 5.7e-01 6.4e-05 Leachate–steel slag 2.7e-01 7.1e-01 Scrap yard

Mo-93 3.7e-02 0.0e+00 Leachate–industrial–scrap 2.7e-03 7.1e-03 Scrap yard

Cs-135 8.2e-03 0.0e+00 Leachate–industrial–scrap 8.0e-03 3.1e-02 Airborne emissions

Np-237 3.2e+02 5.1e+01 Leachate–industrial–scrap 6.0e+01 1.2e+02 Processing steel slag

a

 Nuclides from which mean normalized EDE exceeds 90th percentile EDE

b

 Group with maximum mean EDE which does not exceed 90th percentile EDE to that group

The corresponding statistics for the seven single-heat scenarios are tabulated in Appendix M-2.

For the 11 radionuclides listed in Table 3.20, the mean normalized effective dose in the critical

group is higher than the 90th percentile effective dose. The critical group for ten of these

nuclides comprises persons drinking water from wells down gradient from an industrial landfill

containing cleared steel scrap. The critical group for the 11th nuclide—Sr-90—comprises

persons drinking water from wells down gradient from a slag storage pile. The group with the

highest effective dose for which the mean does not exceed the 90th percentile might be

considered as an alternate critical group for that nuclide. These potential alternate critical groups

are listed in Table 3.20.

Table 3.20 Normalized mass-based effective doses from selected nuclides (:Sv/y per Bq/g)

Nuclidea Critical group Potential alternate critical groupb

Mean 90th %-ile Scenario Mean 90th %-ile Scenario

C-14 3.3e-02 0.0e+00 Leachate industrial scrap 1.2e-03 3.2e-03 Scrap yard

Mn-53 9.0e-04 0.0e+00 Leachate industrial scrap 6.5e-05 1.7e-04 Scrap yard

Sr-90 4.2e-01 4.8e-05 Leachate steel slag 2.4e-01 6.3e-01 Scrap yard

Mo-93 1.9e-01 0.0e+00 Leachate industrial scrap 5.2e-03 1.4e-02 Scrap yard

Cs-135 8.6e-03 0.0e+00 Leachate industrial scrap 8.2e-03 3.1e-02 Airborne emissions

U-233 5.9e+00 0.0e+00 Leachate industrial scrap 2.7e+00 5.4e+00 Processing steel slag

U-234 4.2e+00 0.0e+00 Leachate industrial scrap 2.6e+00 5.3e+00 Processing steel slag

U-235 5.1e+00 0.0e+00 Leachate industrial scrap 3.4e+00 6.7e+00 Processing steel slag

U-236 3.8e+00 0.0e+00 Leachate industrial scrap 2.4e+00 4.9e+00 Processing steel slag

U-238 3.9e+00 0.0e+00 Leachate industrial scrap 2.5e+00 4.9e+00 Processing steel slag

Np-237 2.9e+01 4.8e+00 Leachate industrial scrap 7.9e+00 2.1e+01 Scrap yard

a

 Nuclides from which mean normalized effective dose exceeds 90th percentile effective dose

b

 Group with maximum mean effective dose which does not exceed 90th percentile effective dose to that group
Recycling and Disposal of Steel Scrap Chapter 3

NUREG-1640 3-98

Figure 3.6 Scenarios giving rise to effective dose-critical groups for steel
Chapter 3 Recycling and Disposal of Steel Scrap

3-99 NUREG-1640

Table 3.21 Normalized mass-based effective dose equivalents to critical groups for steel

Radionuclide

:Sv/y per Bq/g mrem/y per pCi/g

Scenario

Mean

Percentilea

Mean

Percentilea

5th 50th 95th 5th 50th 95th

H-3 1.9e-02 0.0e+00 1.4e-05 7.3e-02 7.2e-05 0.0e+00 5.0e-08 2.7e-04 Leachate-industrial-scrap

C-14 3.2e-02 0.0e+00 0.0e+00 4.8e-02 1.2e-04 0.0e+00 0.0e+00 1.8e-04 Leachate-industrial-scrap

Na-22 4.2e+01 4.2e+00 2.1e+01 1.6e+02 1.6e-01 1.5e-02 7.9e-02 5.8e-01 Scrap yard

P-32 5.7e-02 5.5e-03 2.9e-02 2.1e-01 2.1e-04 2.0e-05 1.1e-04 7.7e-04 Scrap yard

S-35 3.7e-04 3.9e-05 1.9e-04 1.4e-03 1.4e-06 1.4e-07 7.1e-07 5.1e-06 Scrap yard

Cl-36 1.7e+00 0.0e+00 0.0e+00 7.3e+00 6.4e-03 0.0e+00 0.0e+00 2.7e-02 Leachate-steel slag

K-40 3.4e+00 3.4e-01 1.7e+00 1.3e+01 1.3e-02 1.2e-03 6.4e-03 4.6e-02 Scrap yard

Ca-41 2.1e-01 0.0e+00 0.0e+00 8.9e-01 7.8e-04 0.0e+00 0.0e+00 3.3e-03 Leachate-steel slag

Ca-45 2.0e-03 1.8e-04 1.0e-03 7.7e-03 7.5e-06 6.7e-07 3.8e-06 2.8e-05 Scrap yard

Sc-46 3.8e+01 3.7e+00 1.9e+01 1.4e+02 1.4e-01 1.4e-02 7.0e-02 5.2e-01 Scrap yard

Cr-51 3.8e-01 2.1e-02 1.7e-01 1.6e+00 1.4e-03 7.6e-05 6.1e-04 5.9e-03 Scrap disposal-industrial

Mn-53 8.8e-04 0.0e+00 0.0e+00 0.0e+00 3.2e-06 0.0e+00 0.0e+00 0.0e+00 Leachate-industrial-scrap

Mn-54 1.6e+01 1.6e+00 8.1e+00 5.9e+01 5.9e-02 5.9e-03 3.0e-02 2.2e-01 Scrap yard

Fe-55 4.6e-04 4.4e-05 2.3e-04 1.7e-03 1.7e-06 1.6e-07 8.6e-07 6.3e-06 Scrap yard

Fe-59 2.1e+01 2.1e+00 1.1e+01 7.8e+01 7.8e-02 7.7e-03 4.0e-02 2.9e-01 Scrap yard

Co-56 6.8e+01 6.7e+00 3.4e+01 2.5e+02 2.5e-01 2.5e-02 1.3e-01 9.3e-01 Scrap yard

Co-57 1.2e+00 6.5e-02 5.3e-01 5.1e+00 4.5e-03 2.4e-04 1.9e-03 1.9e-02 Scrap disposal-industrial

Co-58 1.7e+01 1.7e+00 8.6e+00 6.3e+01 6.3e-02 6.2e-03 3.2e-02 2.3e-01 Scrap yard

Co-60 5.2e+01 5.2e+00 2.7e+01 1.9e+02 1.9e-01 1.9e-02 9.8e-02 7.2e-01 Scrap yard

Ni-59 4.6e-04 5.2e-05 2.4e-04 1.6e-03 1.7e-06 1.9e-07 8.8e-07 6.1e-06 Scrap yard

Ni-63 4.7e-04 4.7e-05 2.4e-04 1.7e-03 1.8e-06 1.7e-07 9.0e-07 6.4e-06 Scrap yard

Zn-65 1.5e+01 4.5e+00 1.0e+01 4.7e+01 5.6e-02 1.6e-02 3.8e-02 1.7e-01 EAF dust-dump trailer

As-73 2.2e-02 1.2e-03 9.6e-03 9.3e-02 8.2e-05 4.4e-06 3.6e-05 3.4e-04 Scrap disposal-industrial

Se-75 5.9e+00 1.7e+00 4.0e+00 1.8e+01 2.2e-02 6.3e-03 1.5e-02 6.8e-02 EAF dust-dump trailer

Sr-85 7.6e+00 7.5e-01 3.9e+00 2.8e+01 2.8e-02 2.8e-03 1.4e-02 1.0e-01 Scrap yard

Sr-89 6.3e-02 6.4e-03 3.2e-02 2.3e-01 2.3e-04 2.4e-05 1.2e-04 8.6e-04 Scrap yard

Sr-90 5.7e-01 0.0e+00 0.0e+00 1.5e-01 2.1e-03 0.0e+00 0.0e+00 5.5e-04 Leachate-steel slag

Y-91 1.4e-01 1.4e-02 6.9e-02 5.0e-01 5.0e-04 5.1e-05 2.6e-04 1.9e-03 Scrap yard

Zr-93 9.3e-03 1.2e-03 5.1e-03 2.8e-02 3.4e-05 4.3e-06 1.9e-05 1.0e-04 Processing steel slag

Zr-95 1.5e+01 1.5e+00 7.6e+00 5.5e+01 5.6e-02 5.5e-03 2.8e-02 2.0e-01 Scrap yard

Nb-93m 3.3e-03 4.1e-04 1.9e-03 1.0e-02 1.2e-05 1.5e-06 6.9e-06 3.8e-05 Handling slag

Nb-94 3.0e+01 3.0e+00 1.5e+01 1.1e+02 1.1e-01 1.1e-02 5.7e-02 4.1e-01 Scrap yard

Nb-95 1.2e+01 1.2e+00 6.1e+00 4.5e+01 4.5e-02 4.4e-03 2.3e-02 1.7e-01 Scrap yard

Mo-93 3.7e-02 0.0e+00 0.0e+00 4.2e-02 1.4e-04 0.0e+00 0.0e+00 1.6e-04 Leachate-industrial-scrap

Tc-97 1.9e-01 0.0e+00 0.0e+00 8.1e-01 6.9e-04 0.0e+00 0.0e+00 3.0e-03 Leachate-industrial-scrap

Tc-97m 4.5e-03 2.4e-04 2.0e-03 1.9e-02 1.7e-05 9.0e-07 7.2e-06 7.0e-05 Scrap disposal-industrial

Tc-99 1.6e+00 0.0e+00 0.0e+00 6.9e+00 5.9e-03 0.0e+00 0.0e+00 2.6e-02 Leachate-industrial-scrap

Ru-103 7.1e+00 7.0e-01 3.6e+00 2.6e+01 2.6e-02 2.6e-03 1.3e-02 9.8e-02 Scrap yard

Ru-106 4.2e+00 4.2e-01 2.1e+00 1.5e+01 1.5e-02 1.5e-03 7.8e-03 5.7e-02 Scrap yard

a

 5th percentile to 95th percentile = 90% confidence interval
Recycling and Disposal of Steel Scrap Chapter 3

Table 3.21 Normalized mass-based effective dose equivalents to critical groups for steel

Radionuclide

:Sv/y per Bq/g mrem/y per pCi/g

Scenario

Mean

Percentilea

Mean

Percentilea

5th 50th 95th 5th 50th 95th

NUREG-1640 3-100

Ag-108m 2.9e+01 2.9e+00 1.5e+01 1.1e+02 1.1e-01 1.1e-02 5.4e-02 3.9e-01 Scrap yard

Ag-110m 5.2e+01 5.2e+00 2.6e+01 1.9e+02 1.9e-01 1.9e-02 9.8e-02 7.1e-01 Scrap yard

Cd-109 6.5e-02 3.5e-03 2.8e-02 2.7e-01 2.4e-04 1.3e-05 1.0e-04 1.0e-03 Scrap disposal-industrial

Sn-113 3.7e+00 3.7e-01 1.9e+00 1.4e+01 1.4e-02 1.4e-03 7.0e-03 5.1e-02 Scrap yard

Sb-124 3.4e+01 3.3e+00 1.7e+01 1.2e+02 1.2e-01 1.2e-02 6.3e-02 4.6e-01 Scrap yard

Sb-125 7.1e+00 7.1e-01 3.6e+00 2.6e+01 2.6e-02 2.6e-03 1.3e-02 9.7e-02 Scrap yard

Te-123m 1.5e+00 8.1e-02 6.5e-01 6.3e+00 5.6e-03 3.0e-04 2.4e-03 2.3e-02 Scrap disposal-industrial

Te-127m 1.0e-01 3.0e-02 7.1e-02 3.2e-01 3.9e-04 1.1e-04 2.6e-04 1.2e-03 EAF dust-dump trailer

I-125 7.3e-01 2.1e-01 6.3e-01 1.6e+00 2.7e-03 8.0e-04 2.3e-03 5.9e-03 Airborne emissions

I-129 2.2e+02 0.0e+00 0.0e+00 7.7e+02 8.2e-01 0.0e+00 0.0e+00 2.9e+00 Leachate-steel slag

I-131 3.7e+00 1.9e-01 1.6e+00 1.5e+01 1.4e-02 7.0e-04 5.8e-03 5.7e-02 Scrap disposal-industrial

Cs-134 4.4e+01 1.3e+01 3.0e+01 1.3e+02 1.6e-01 4.9e-02 1.1e-01 5.0e-01 EAF dust-dump trailer

Cs-135 8.2e-03 0.0e+00 0.0e+00 0.0e+00 3.0e-05 0.0e+00 0.0e+00 0.0e+00 Leachate-industrial-scrap

Cs-137 1.6e+01 4.9e+00 1.1e+01 5.0e+01 6.0e-02 1.8e-02 4.1e-02 1.9e-01 EAF dust-dump trailer

Ba-133 4.9e+00 4.9e-01 2.5e+00 1.8e+01 1.8e-02 1.8e-03 9.1e-03 6.7e-02 Scrap yard

Ce-139 1.5e+00 8.2e-02 6.6e-01 6.4e+00 5.7e-03 3.0e-04 2.5e-03 2.4e-02 Scrap disposal-industrial

Ce-141 7.1e-01 3.8e-02 3.1e-01 3.0e+00 2.6e-03 1.4e-04 1.1e-03 1.1e-02 Scrap disposal-industrial

Ce-144 1.0e+00 1.0e-01 5.1e-01 3.7e+00 3.7e-03 3.8e-04 1.9e-03 1.4e-02 Scrap yard

Pm-147 4.4e-03 5.3e-04 2.4e-03 1.3e-02 1.6e-05 2.0e-06 9.0e-06 4.9e-05 Handling slag

Sm-151 3.3e-03 4.0e-04 1.8e-03 9.9e-03 1.2e-05 1.5e-06 6.6e-06 3.7e-05 Processing steel slag

Eu-152 2.2e+01 2.2e+00 1.1e+01 8.1e+01 8.1e-02 8.1e-03 4.1e-02 3.0e-01 Scrap yard

Eu-154 2.2e+01 2.1e+00 1.1e+01 8.0e+01 8.0e-02 7.9e-03 4.0e-02 2.9e-01 Scrap yard

Eu-155 4.5e-01 2.4e-02 1.9e-01 1.9e+00 1.7e-03 8.9e-05 7.2e-04 6.9e-03 Scrap disposal-industrial

Gd-153 5.9e-01 3.2e-02 2.6e-01 2.5e+00 2.2e-03 1.2e-04 9.5e-04 9.1e-03 Scrap disposal-industrial

Tb-160 2.0e+01 1.9e+00 1.0e+01 7.3e+01 7.3e-02 7.2e-03 3.7e-02 2.7e-01 Scrap yard

Tm-170 3.6e-02 1.9e-03 1.6e-02 1.5e-01 1.3e-04 7.1e-06 5.7e-05 5.5e-04 Scrap disposal-industrial

Tm-171 2.7e-03 1.5e-04 1.2e-03 1.1e-02 1.0e-05 5.4e-07 4.4e-06 4.2e-05 Scrap disposal-industrial

Ta-182 2.3e+01 2.3e+00 1.2e+01 8.6e+01 8.6e-02 8.5e-03 4.4e-02 3.2e-01 Scrap yard

W-181 1.8e-01 9.8e-03 7.9e-02 7.6e-01 6.8e-04 3.6e-05 2.9e-04 2.8e-03 Scrap disposal-industrial

W-185 2.0e-03 2.2e-04 1.0e-03 7.3e-03 7.5e-06 8.1e-07 3.8e-06 2.7e-05 Scrap yard

Os-185 1.4e+01 4.1e+00 9.6e+00 4.4e+01 5.3e-02 1.5e-02 3.5e-02 1.6e-01 EAF dust-dump trailer

Ir-192 1.1e+01 1.1e+00 5.7e+00 4.2e+01 4.1e-02 4.1e-03 2.1e-02 1.5e-01 Scrap yard

Tl-204 1.2e-02 1.2e-03 6.0e-03 4.2e-02 4.3e-05 4.5e-06 2.2e-05 1.6e-04 Scrap yard

Pb-210 1.2e+01 5.1e+00 1.2e+01 2.2e+01 4.5e-02 1.9e-02 4.3e-02 8.0e-02 Transferring EAF dust

Bi-207 4.3e+01 1.3e+01 2.9e+01 1.3e+02 1.6e-01 4.8e-02 1.1e-01 4.9e-01 EAF dust-dump trailer

Po-210 3.3e+00 1.5e+00 3.2e+00 5.8e+00 1.2e-02 5.6e-03 1.2e-02 2.1e-02 Transferring EAF dust

Ra-226 3.5e+01 3.6e+00 1.8e+01 1.3e+02 1.3e-01 1.3e-02 6.6e-02 4.8e-01 Scrap yard

Ra-228 1.8e+01 1.8e+00 9.1e+00 6.6e+01 6.7e-02 6.8e-03 3.4e-02 2.4e-01 Scrap yard

a

 5th percentile to 95th percentile = 90% confidence interval
Chapter 3 Recycling and Disposal of Steel Scrap

Table 3.21 Normalized mass-based effective dose equivalents to critical groups for steel

Radionuclide

:Sv/y per Bq/g mrem/y per pCi/g

Scenario

Mean

Percentilea

Mean

Percentilea

5th 50th 95th 5th 50th 95th

3-101 NUREG-1640

Ac-227 1.4e+02 1.7e+01 8.0e+01 4.4e+02 5.3e-01 6.4e-02 3.0e-01 1.6e+00 Handling slag

Th-228 4.9e+01 6.4e+00 2.8e+01 1.5e+02 1.8e-01 2.4e-02 1.0e-01 5.5e-01 Handling slag

Th-229 1.9e+02 2.3e+01 1.0e+02 5.6e+02 6.9e-01 8.5e-02 3.8e-01 2.1e+00 Processing steel slag

Th-230 2.7e+01 3.4e+00 1.5e+01 8.4e+01 1.0e-01 1.2e-02 5.6e-02 3.1e-01 Processing steel slag

Th-232 1.2e+02 1.5e+01 6.7e+01 3.7e+02 4.5e-01 5.5e-02 2.5e-01 1.4e+00 Processing steel slag

Pa-231 9.5e+01 1.2e+01 5.2e+01 2.9e+02 3.5e-01 4.3e-02 1.9e-01 1.1e+00 Processing steel slag

U-232 7.5e+01 9.1e+00 4.1e+01 2.3e+02 2.8e-01 3.4e-02 1.5e-01 8.5e-01 Processing steel slag

U-233 1.4e+01 1.7e+00 7.7e+00 4.3e+01 5.2e-02 6.4e-03 2.9e-02 1.6e-01 Processing steel slag

U-234 1.4e+01 1.7e+00 7.6e+00 4.2e+01 5.1e-02 6.3e-03 2.8e-02 1.5e-01 Processing steel slag

U-235 1.4e+01 1.7e+00 7.7e+00 4.2e+01 5.1e-02 6.2e-03 2.9e-02 1.6e-01 Handling slag

U-236 1.3e+01 1.6e+00 7.2e+00 4.0e+01 4.8e-02 5.9e-03 2.6e-02 1.5e-01 Processing steel slag

U-238 1.3e+01 1.6e+00 6.9e+00 3.8e+01 4.7e-02 5.8e-03 2.6e-02 1.4e-01 Processing steel slag

Np-237 3.2e+02 0.0e+00 0.0e+00 6.1e+02 1.2e+00 0.0e+00 0.0e+00 2.3e+00 Leachate-industrial-scrap

Pu-236 1.4e+01 1.6e+00 7.5e+00 4.2e+01 5.0e-02 6.1e-03 2.8e-02 1.5e-01 Handling slag

Pu-238 3.1e+01 3.8e+00 1.7e+01 9.4e+01 1.2e-01 1.4e-02 6.3e-02 3.5e-01 Processing steel slag

Pu-239 3.3e+01 4.1e+00 1.8e+01 1.0e+02 1.2e-01 1.5e-02 6.8e-02 3.8e-01 Processing steel slag

Pu-240 3.3e+01 4.1e+00 1.8e+01 1.0e+02 1.2e-01 1.5e-02 6.8e-02 3.8e-01 Processing steel slag

Pu-241 5.8e-01 6.7e-02 3.0e-01 2.1e+00 2.1e-03 2.5e-04 1.1e-03 7.7e-03 Scrap yard

Pu-242 3.2e+01 3.9e+00 1.7e+01 9.7e+01 1.2e-01 1.4e-02 6.4e-02 3.6e-01 Processing steel slag

Pu-244 3.5e+01 4.4e+00 1.9e+01 1.1e+02 1.3e-01 1.6e-02 7.1e-02 3.9e-01 Processing steel slag

Am-241 4.8e+01 5.8e+00 2.6e+01 1.4e+02 1.8e-01 2.2e-02 9.7e-02 5.3e-01 Processing steel slag

Am-242m 4.7e+01 5.8e+00 2.6e+01 1.4e+02 1.7e-01 2.1e-02 9.6e-02 5.3e-01 Processing steel slag

Am-243 4.8e+01 6.0e+00 2.7e+01 1.5e+02 1.8e-01 2.2e-02 9.8e-02 5.4e-01 Processing steel slag

Cm-242 1.6e+00 2.0e-01 8.9e-01 4.9e+00 6.0e-03 7.4e-04 3.3e-03 1.8e-02 Handling slag

Cm-243 3.3e+01 4.0e+00 1.9e+01 1.0e+02 1.2e-01 1.5e-02 6.9e-02 3.8e-01 Handling slag

Cm-244 2.6e+01 3.1e+00 1.5e+01 8.1e+01 9.7e-02 1.2e-02 5.4e-02 3.0e-01 Handling slag

Cm-245 4.9e+01 6.1e+00 2.7e+01 1.5e+02 1.8e-01 2.2e-02 1.0e-01 5.5e-01 Processing steel slag

Cm-246 4.8e+01 6.0e+00 2.6e+01 1.5e+02 1.8e-01 2.2e-02 9.8e-02 5.4e-01 Processing steel slag

Cm-247 4.7e+01 5.9e+00 2.6e+01 1.4e+02 1.7e-01 2.2e-02 9.7e-02 5.3e-01 Processing steel slag

Cm-248 1.8e+02 2.2e+01 9.7e+01 5.4e+02 6.6e-01 8.1e-02 3.6e-01 2.0e+00 Processing steel slag

Bk-249 1.5e-01 1.7e-02 8.0e-02 4.4e-01 5.4e-04 6.5e-05 3.0e-04 1.6e-03 Handling slag

Cf-248 5.1e+00 6.2e-01 2.8e+00 1.6e+01 1.9e-02 2.3e-03 1.0e-02 5.7e-02 Handling slag

Cf-249 4.4e+01 5.6e+00 2.4e+01 1.3e+02 1.6e-01 2.1e-02 9.0e-02 5.0e-01 Processing steel slag

Cf-250 2.2e+01 2.6e+00 1.2e+01 6.6e+01 8.1e-02 9.8e-03 4.5e-02 2.5e-01 Handling slag

Cf-251 4.3e+01 5.3e+00 2.4e+01 1.3e+02 1.6e-01 2.0e-02 8.7e-02 4.8e-01 Processing steel slag

Cf-252 1.6e+01 2.0e+00 9.0e+00 4.9e+01 6.0e-02 7.3e-03 3.3e-02 1.8e-01 Handling slag

Cf-254 3.3e+02 3.3e+01 1.7e+02 1.2e+03 1.2e+00 1.2e-01 6.2e-01 4.5e+00 Scrap yard

Es-254 2.0e+01 2.2e+00 1.0e+01 7.5e+01 7.6e-02 8.0e-03 3.9e-02 2.8e-01 Scrap yard

a

 5th percentile to 95th percentile = 90% confidence interval
Recycling and Disposal of Steel Scrap Chapter 3

NUREG-1640 3-102

Table 3.22 Normalized surficial effective dose equivalents to critical groups for steel

Radionuclide

:Sv/y per Bq/cm2 mrem/y per pCi/cm2

Scenario

Mean

Percentilea

Mean

Percentilea

5th 50th 95th 5th 50th 95th

H-3 3.8e-03 0.0e+00 2.7e-06 1.4e-02 1.4e-05 0.0e+00 9.9e-09 5.2e-05 Leachate-industrial-scrap

C-14 6.3e-03 0.0e+00 0.0e+00 9.5e-03 2.3e-05 0.0e+00 0.0e+00 3.5e-05 Leachate-industrial-scrap

Na-22 8.3e+00 8.4e-01 4.2e+00 3.0e+01 3.1e-02 3.1e-03 1.6e-02 1.1e-01 Scrap yard

P-32 1.1e-02 1.1e-03 5.6e-03 4.1e-02 4.1e-05 4.1e-06 2.1e-05 1.5e-04 Scrap yard

S-35 7.4e-05 7.7e-06 3.8e-05 2.7e-04 2.7e-07 2.9e-08 1.4e-07 1.0e-06 Scrap yard

Cl-36 3.4e-01 0.0e+00 0.0e+00 1.5e+00 1.3e-03 0.0e+00 0.0e+00 5.4e-03 Leachate-steel slag

K-40 6.7e-01 6.8e-02 3.4e-01 2.4e+00 2.5e-03 2.5e-04 1.3e-03 9.0e-03 Scrap yard

Ca-41 4.2e-02 0.0e+00 0.0e+00 1.8e-01 1.5e-04 0.0e+00 0.0e+00 6.5e-04 Leachate-steel slag

Ca-45 4.0e-04 3.6e-05 2.0e-04 1.5e-03 1.5e-06 1.3e-07 7.5e-07 5.6e-06 Scrap yard

Sc-46 7.4e+00 7.4e-01 3.8e+00 2.7e+01 2.8e-02 2.8e-03 1.4e-02 1.0e-01 Scrap yard

Cr-51 7.6e-02 4.2e-03 3.3e-02 3.2e-01 2.8e-04 1.5e-05 1.2e-04 1.2e-03 Scrap disposal-industrial

Mn-53 1.7e-04 0.0e+00 0.0e+00 0.0e+00 6.4e-07 0.0e+00 0.0e+00 0.0e+00 Leachate-industrial-scrap

Mn-54 3.2e+00 3.2e-01 1.6e+00 1.2e+01 1.2e-02 1.2e-03 5.9e-03 4.3e-02 Scrap yard

Fe-55 9.1e-05 8.8e-06 4.6e-05 3.4e-04 3.4e-07 3.2e-08 1.7e-07 1.2e-06 Scrap yard

Fe-59 4.2e+00 4.1e-01 2.1e+00 1.5e+01 1.5e-02 1.5e-03 7.8e-03 5.7e-02 Scrap yard

Co-56 1.3e+01 1.3e+00 6.8e+00 4.9e+01 5.0e-02 5.0e-03 2.5e-02 1.8e-01 Scrap yard

Co-57 2.4e-01 1.3e-02 1.0e-01 1.0e+00 8.9e-04 4.9e-05 3.9e-04 3.7e-03 Scrap disposal-industrial

Co-58 3.3e+00 3.3e-01 1.7e+00 1.2e+01 1.2e-02 1.2e-03 6.2e-03 4.5e-02 Scrap yard

Co-60 1.0e+01 1.0e+00 5.2e+00 3.8e+01 3.8e-02 3.9e-03 1.9e-02 1.4e-01 Scrap yard

Ni-59 9.1e-05 1.0e-05 4.7e-05 3.3e-04 3.4e-07 3.8e-08 1.7e-07 1.2e-06 Scrap yard

Ni-63 9.4e-05 9.5e-06 4.8e-05 3.5e-04 3.5e-07 3.5e-08 1.8e-07 1.3e-06 Scrap yard

Zn-65 3.0e+00 9.0e-01 2.0e+00 8.8e+00 1.1e-02 3.3e-03 7.5e-03 3.3e-02 EAF dust-dump trailer

As-73 4.4e-03 2.4e-04 1.9e-03 1.8e-02 1.6e-05 9.0e-07 7.1e-06 6.8e-05 Scrap disposal-industrial

Se-75 1.2e+00 3.5e-01 7.9e-01 3.4e+00 4.3e-03 1.3e-03 2.9e-03 1.3e-02 EAF dust-dump trailer

Sr-85 1.5e+00 1.5e-01 7.6e-01 5.5e+00 5.6e-03 5.6e-04 2.8e-03 2.0e-02 Scrap yard

Sr-89 1.2e-02 1.3e-03 6.3e-03 4.5e-02 4.6e-05 4.7e-06 2.3e-05 1.7e-04 Scrap yard

Sr-90 1.2e-01 0.0e+00 0.0e+00 2.9e-02 4.4e-04 0.0e+00 0.0e+00 1.1e-04 Leachate-steel slag

Y-91 2.7e-02 2.7e-03 1.4e-02 9.8e-02 9.9e-05 1.0e-05 5.0e-05 3.6e-04 Scrap yard

Zr-93 1.8e-03 2.3e-04 1.0e-03 5.6e-03 6.8e-06 8.3e-07 3.8e-06 2.1e-05 Processing steel slag

Zr-95 3.0e+00 3.0e-01 1.5e+00 1.1e+01 1.1e-02 1.1e-03 5.5e-03 4.0e-02 Scrap yard

Nb-93m 6.6e-04 8.2e-05 3.7e-04 2.0e-03 2.4e-06 3.0e-07 1.4e-06 7.4e-06 Handling slag

Nb-94 6.0e+00 6.0e-01 3.0e+00 2.2e+01 2.2e-02 2.2e-03 1.1e-02 8.0e-02 Scrap yard

Nb-95 2.4e+00 2.4e-01 1.2e+00 8.8e+00 8.9e-03 8.7e-04 4.5e-03 3.3e-02 Scrap yard

Mo-93 7.3e-03 0.0e+00 0.0e+00 8.2e-03 2.7e-05 0.0e+00 0.0e+00 3.0e-05 Leachate-industrial-scrap

Tc-97 3.7e-02 0.0e+00 0.0e+00 1.6e-01 1.4e-04 0.0e+00 0.0e+00 6.0e-04 Leachate-industrial-scrap

Tc-97m 8.9e-04 4.9e-05 3.9e-04 3.7e-03 3.3e-06 1.8e-07 1.4e-06 1.4e-05 Scrap disposal-industrial

Tc-99 3.2e-01 0.0e+00 0.0e+00 1.4e+00 1.2e-03 0.0e+00 0.0e+00 5.1e-03 Leachate-industrial-scrap

Ru-103 1.4e+00 1.4e-01 7.1e-01 5.2e+00 5.2e-03 5.1e-04 2.6e-03 1.9e-02 Scrap yard

Ru-106 8.2e-01 8.3e-02 4.2e-01 3.0e+00 3.1e-03 3.1e-04 1.5e-03 1.1e-02 Scrap yard

a

 5th percentile to 95th percentile = 90% confidence interval
Chapter 3 Recycling and Disposal of Steel Scrap

Table 3.22 Normalized surficial effective dose equivalents to critical groups for steel

Radionuclide

:Sv/y per Bq/cm2 mrem/y per pCi/cm2

Scenario

Mean

Percentilea

Mean

Percentilea

5th 50th 95th 5th 50th 95th

3-103 NUREG-1640

Ag-108m 5.7e+00 5.8e-01 2.9e+00 2.1e+01 2.1e-02 2.1e-03 1.1e-02 7.7e-02 Scrap yard

Ag-110m 1.0e+01 1.0e+00 5.2e+00 3.8e+01 3.8e-02 3.8e-03 1.9e-02 1.4e-01 Scrap yard

Cd-109 1.3e-02 7.1e-04 5.5e-03 5.3e-02 4.7e-05 2.6e-06 2.0e-05 2.0e-04 Scrap disposal-industrial

Sn-113 7.4e-01 7.5e-02 3.7e-01 2.7e+00 2.7e-03 2.8e-04 1.4e-03 1.0e-02 Scrap yard

Sb-124 6.6e+00 6.6e-01 3.3e+00 2.4e+01 2.5e-02 2.4e-03 1.2e-02 9.0e-02 Scrap yard

Sb-125 1.4e+00 1.4e-01 7.1e-01 5.1e+00 5.2e-03 5.2e-04 2.6e-03 1.9e-02 Scrap yard

Te-123m 3.0e-01 1.6e-02 1.3e-01 1.2e+00 1.1e-03 6.1e-05 4.8e-04 4.6e-03 Scrap disposal-industrial

Te-127m 2.1e-02 6.1e-03 1.4e-02 6.0e-02 7.6e-05 2.3e-05 5.2e-05 2.2e-04 EAF dust-dump trailer

I-125 1.4e-01 4.3e-02 1.2e-01 3.1e-01 5.3e-04 1.6e-04 4.6e-04 1.2e-03 Airborne emissions

I-129 4.4e+01 0.0e+00 0.0e+00 1.5e+02 1.6e-01 0.0e+00 0.0e+00 5.7e-01 Leachate-steel slag

I-131 7.2e-01 3.9e-02 3.1e-01 3.0e+00 2.7e-03 1.4e-04 1.1e-03 1.1e-02 Scrap disposal-industrial

Cs-134 8.6e+00 2.6e+00 5.8e+00 2.6e+01 3.2e-02 9.6e-03 2.2e-02 9.5e-02 EAF dust-dump trailer

Cs-135 1.7e-03 0.0e+00 0.0e+00 0.0e+00 6.3e-06 0.0e+00 0.0e+00 0.0e+00 Leachate-industrial-scrap

Cs-137 3.2e+00 9.7e-01 2.2e+00 9.6e+00 1.2e-02 3.6e-03 8.1e-03 3.5e-02 EAF dust-dump trailer

Ba-133 9.7e-01 9.7e-02 4.9e-01 3.5e+00 3.6e-03 3.6e-04 1.8e-03 1.3e-02 Scrap yard

Ce-139 3.0e-01 1.7e-02 1.3e-01 1.3e+00 1.1e-03 6.2e-05 4.9e-04 4.7e-03 Scrap disposal-industrial

Ce-141 1.4e-01 7.7e-03 6.1e-02 5.8e-01 5.2e-04 2.9e-05 2.3e-04 2.2e-03 Scrap disposal-industrial

Ce-144 2.0e-01 2.0e-02 1.0e-01 7.3e-01 7.4e-04 7.6e-05 3.8e-04 2.7e-03 Scrap yard

Pm-147 8.6e-04 1.1e-04 4.8e-04 2.6e-03 3.2e-06 4.0e-07 1.8e-06 9.7e-06 Handling slag

Sm-151 6.4e-04 7.9e-05 3.6e-04 2.0e-03 2.4e-06 2.9e-07 1.3e-06 7.3e-06 Processing steel slag

Eu-152 4.3e+00 4.4e-01 2.2e+00 1.6e+01 1.6e-02 1.6e-03 8.1e-03 5.9e-02 Scrap yard

Eu-154 4.3e+00 4.3e-01 2.2e+00 1.6e+01 1.6e-02 1.6e-03 8.0e-03 5.8e-02 Scrap yard

Eu-155 8.8e-02 4.9e-03 3.8e-02 3.7e-01 3.3e-04 1.8e-05 1.4e-04 1.4e-03 Scrap disposal-industrial

Gd-153 1.2e-01 6.5e-03 5.1e-02 4.9e-01 4.3e-04 2.4e-05 1.9e-04 1.8e-03 Scrap disposal-industrial

Tb-160 3.9e+00 3.9e-01 2.0e+00 1.4e+01 1.4e-02 1.4e-03 7.2e-03 5.3e-02 Scrap yard

Tm-170 7.1e-03 3.9e-04 3.1e-03 2.9e-02 2.6e-05 1.4e-06 1.1e-05 1.1e-04 Scrap disposal-industrial

Tm-171 5.4e-04 3.0e-05 2.3e-04 2.3e-03 2.0e-06 1.1e-07 8.6e-07 8.3e-06 Scrap disposal-industrial

Ta-182 4.6e+00 4.6e-01 2.3e+00 1.7e+01 1.7e-02 1.7e-03 8.6e-03 6.2e-02 Scrap yard

W-181 3.6e-02 2.0e-03 1.6e-02 1.5e-01 1.3e-04 7.4e-06 5.8e-05 5.6e-04 Scrap disposal-industrial

W-185 4.0e-04 4.3e-05 2.0e-04 1.4e-03 1.5e-06 1.6e-07 7.5e-07 5.4e-06 Scrap yard

Os-185 2.8e+00 8.3e-01 1.9e+00 8.2e+00 1.0e-02 3.1e-03 7.0e-03 3.0e-02 EAF dust-dump trailer

Ir-192 2.2e+00 2.2e-01 1.1e+00 8.1e+00 8.2e-03 8.2e-04 4.1e-03 3.0e-02 Scrap yard

Tl-204 2.3e-03 2.4e-04 1.2e-03 8.4e-03 8.5e-06 9.0e-07 4.3e-06 3.1e-05 Scrap yard

Pb-210 2.4e+00 1.0e+00 2.3e+00 4.2e+00 8.9e-03 3.7e-03 8.5e-03 1.6e-02 Transferring EAF dust

Bi-207 8.5e+00 2.6e+00 5.8e+00 2.5e+01 3.1e-02 9.5e-03 2.1e-02 9.4e-02 EAF dust-dump trailer

Po-210 6.6e-01 3.0e-01 6.3e-01 1.1e+00 2.4e-03 1.1e-03 2.3e-03 4.2e-03 Transferring EAF dust

Ra-226 7.0e+00 7.2e-01 3.5e+00 2.5e+01 2.6e-02 2.7e-03 1.3e-02 9.4e-02 Scrap yard

Ra-228 3.6e+00 3.7e-01 1.8e+00 1.3e+01 1.3e-02 1.4e-03 6.7e-03 4.8e-02 Scrap yard

a

 5th percentile to 95th percentile = 90% confidence interval
Recycling and Disposal of Steel Scrap Chapter 3

Table 3.22 Normalized surficial effective dose equivalents to critical groups for steel

Radionuclide

:Sv/y per Bq/cm2 mrem/y per pCi/cm2

Scenario

Mean

Percentilea

Mean

Percentilea

5th 50th 95th 5th 50th 95th

NUREG-1640 3-104

Ac-227 2.8e+01 3.5e+00 1.6e+01 8.7e+01 1.0e-01 1.3e-02 5.8e-02 3.2e-01 Processing steel slag

Th-228 9.7e+00 1.3e+00 5.6e+00 2.9e+01 3.6e-02 4.7e-03 2.1e-02 1.1e-01 Handling slag

Th-229 3.6e+01 4.5e+00 2.0e+01 1.1e+02 1.3e-01 1.7e-02 7.4e-02 4.1e-01 Processing steel slag

Th-230 5.4e+00 6.6e-01 3.0e+00 1.7e+01 2.0e-02 2.5e-03 1.1e-02 6.1e-02 Processing steel slag

Th-232 2.4e+01 2.9e+00 1.3e+01 7.3e+01 8.8e-02 1.1e-02 4.9e-02 2.7e-01 Processing steel slag

Pa-231 1.9e+01 2.3e+00 1.0e+01 5.7e+01 6.9e-02 8.5e-03 3.8e-02 2.1e-01 Processing steel slag

U-232 1.5e+01 1.8e+00 8.0e+00 4.5e+01 5.4e-02 6.6e-03 3.0e-02 1.7e-01 Processing steel slag

U-233 2.8e+00 3.4e-01 1.5e+00 8.6e+00 1.0e-02 1.2e-03 5.7e-03 3.2e-02 Processing steel slag

U-234 2.7e+00 3.3e-01 1.5e+00 8.4e+00 1.0e-02 1.2e-03 5.5e-03 3.1e-02 Processing steel slag

U-235 2.7e+00 3.4e-01 1.5e+00 8.2e+00 1.0e-02 1.3e-03 5.6e-03 3.0e-02 Handling slag

U-236 2.6e+00 3.1e-01 1.4e+00 7.9e+00 9.5e-03 1.2e-03 5.2e-03 2.9e-02 Processing steel slag

U-238 2.5e+00 3.0e-01 1.4e+00 7.6e+00 9.2e-03 1.1e-03 5.1e-03 2.8e-02 Processing steel slag

Np-237 6.2e+01 0.0e+00 0.0e+00 1.2e+02 2.3e-01 0.0e+00 0.0e+00 4.6e-01 Leachate-industrial-scrap

Pu-236 2.7e+00 3.3e-01 1.5e+00 8.2e+00 9.9e-03 1.2e-03 5.5e-03 3.0e-02 Handling slag

Pu-238 6.1e+00 7.5e-01 3.4e+00 1.9e+01 2.3e-02 2.8e-03 1.3e-02 7.0e-02 Processing steel slag

Pu-239 6.6e+00 8.1e-01 3.6e+00 2.0e+01 2.4e-02 3.0e-03 1.3e-02 7.5e-02 Processing steel slag

Pu-240 6.6e+00 8.1e-01 3.6e+00 2.0e+01 2.4e-02 3.0e-03 1.3e-02 7.5e-02 Processing steel slag

Pu-241 1.1e-01 1.3e-02 6.0e-02 4.1e-01 4.2e-04 4.9e-05 2.2e-04 1.5e-03 Scrap yard

Pu-242 6.2e+00 7.7e-01 3.5e+00 1.9e+01 2.3e-02 2.8e-03 1.3e-02 7.1e-02 Processing steel slag

Pu-244 6.8e+00 8.6e-01 3.8e+00 2.1e+01 2.5e-02 3.2e-03 1.4e-02 7.6e-02 Processing steel slag

Am-241 9.4e+00 1.2e+00 5.2e+00 2.9e+01 3.5e-02 4.3e-03 1.9e-02 1.1e-01 Processing steel slag

Am-242m 9.3e+00 1.1e+00 5.1e+00 2.9e+01 3.4e-02 4.2e-03 1.9e-02 1.1e-01 Processing steel slag

Am-243 9.5e+00 1.2e+00 5.3e+00 2.9e+01 3.5e-02 4.3e-03 1.9e-02 1.1e-01 Processing steel slag

Cm-242 3.2e-01 4.0e-02 1.8e-01 9.7e-01 1.2e-03 1.5e-04 6.6e-04 3.6e-03 Handling slag

Cm-243 6.6e+00 8.1e-01 3.7e+00 2.0e+01 2.4e-02 3.0e-03 1.4e-02 7.4e-02 Handling slag

Cm-244 5.2e+00 6.3e-01 2.9e+00 1.6e+01 1.9e-02 2.3e-03 1.1e-02 5.9e-02 Handling slag

Cm-245 9.7e+00 1.2e+00 5.4e+00 3.0e+01 3.6e-02 4.4e-03 2.0e-02 1.1e-01 Processing steel slag

Cm-246 9.5e+00 1.2e+00 5.3e+00 2.9e+01 3.5e-02 4.3e-03 2.0e-02 1.1e-01 Processing steel slag

Cm-247 9.3e+00 1.2e+00 5.2e+00 2.8e+01 3.4e-02 4.3e-03 1.9e-02 1.1e-01 Processing steel slag

Cm-248 3.5e+01 4.3e+00 1.9e+01 1.1e+02 1.3e-01 1.6e-02 7.2e-02 3.9e-01 Processing steel slag

Bk-249 2.9e-02 3.5e-03 1.6e-02 8.7e-02 1.1e-04 1.3e-05 5.9e-05 3.2e-04 Handling slag

Cf-248 1.0e+00 1.2e-01 5.6e-01 3.1e+00 3.7e-03 4.6e-04 2.1e-03 1.1e-02 Handling slag

Cf-249 8.7e+00 1.1e+00 4.9e+00 2.6e+01 3.2e-02 4.0e-03 1.8e-02 9.8e-02 Processing steel slag

Cf-250 4.3e+00 5.3e-01 2.4e+00 1.3e+01 1.6e-02 2.0e-03 8.9e-03 4.9e-02 Handling slag

Cf-251 8.4e+00 1.0e+00 4.7e+00 2.6e+01 3.1e-02 3.8e-03 1.7e-02 9.5e-02 Processing steel slag

Cf-252 3.2e+00 3.9e-01 1.8e+00 9.8e+00 1.2e-02 1.4e-03 6.6e-03 3.6e-02 Handling slag

Cf-254 6.5e+01 6.7e+00 3.3e+01 2.4e+02 2.4e-01 2.5e-02 1.2e-01 8.8e-01 Scrap yard

Es-254 4.0e+00 4.3e-01 2.1e+00 1.5e+01 1.5e-02 1.6e-03 7.6e-03 5.5e-02 Scrap yard

a

 5th percentile to 95th percentile = 90% confidence interval
Chapter 3 Recycling and Disposal of Steel Scrap

3-105 NUREG-1640

Table 3.23 Normalized mass-based effective doses to critical groups for steel

Radionuclide

:Sv/y per Bq/g mrem/y per pCi/g

Scenario

Mean

Percentilea

Mean

Percentilea

5th 50th 95th 5th 50th 95th

H-3 2.0e-02 0.0e+00 1.4e-05 7.6e-02 7.4e-05 0.0e+00 5.2e-08 2.8e-04 Leachate-industrial-scrap

C-14 3.3e-02 0.0e+00 0.0e+00 4.9e-02 1.2e-04 0.0e+00 0.0e+00 1.8e-04 Leachate-industrial-scrap

Na-22 4.2e+01 4.2e+00 2.1e+01 1.6e+02 1.6e-01 1.5e-02 7.9e-02 5.7e-01 Scrap yard

P-32 5.6e-02 5.4e-03 2.8e-02 2.1e-01 2.1e-04 2.0e-05 1.0e-04 7.6e-04 Scrap yard

S-35 5.5e-04 6.0e-05 2.8e-04 2.0e-03 2.0e-06 2.2e-07 1.0e-06 7.3e-06 Scrap yard

Cl-36 2.0e+00 0.0e+00 0.0e+00 8.3e+00 7.3e-03 0.0e+00 0.0e+00 3.1e-02 Leachate-steel slag

K-40 3.4e+00 3.4e-01 1.7e+00 1.2e+01 1.2e-02 1.2e-03 6.3e-03 4.6e-02 Scrap yard

Ca-41 1.8e-01 0.0e+00 0.0e+00 7.5e-01 6.6e-04 0.0e+00 0.0e+00 2.8e-03 Leachate-steel slag

Ca-45 2.1e-03 2.0e-04 1.1e-03 7.7e-03 7.7e-06 7.5e-07 3.9e-06 2.9e-05 Scrap yard

Sc-46 3.7e+01 3.7e+00 1.9e+01 1.4e+02 1.4e-01 1.4e-02 7.0e-02 5.1e-01 Scrap yard

Cr-51 3.6e-01 1.9e-02 1.5e-01 1.5e+00 1.3e-03 7.1e-05 5.7e-04 5.5e-03 Scrap disposal-industrial

Mn-53 9.0e-04 0.0e+00 0.0e+00 0.0e+00 3.3e-06 0.0e+00 0.0e+00 0.0e+00 Leachate-industrial-scrap

Mn-54 1.6e+01 1.6e+00 8.0e+00 5.8e+01 5.8e-02 5.8e-03 3.0e-02 2.2e-01 Scrap yard

Fe-55 7.5e-04 6.1e-05 3.7e-04 2.9e-03 2.8e-06 2.3e-07 1.4e-06 1.1e-05 Scrap yard

Fe-59 2.1e+01 2.1e+00 1.1e+01 7.7e+01 7.7e-02 7.6e-03 3.9e-02 2.9e-01 Scrap yard

Co-56 6.7e+01 6.7e+00 3.4e+01 2.5e+02 2.5e-01 2.5e-02 1.3e-01 9.3e-01 Scrap yard

Co-57 1.1e+00 6.0e-02 4.8e-01 4.6e+00 4.1e-03 2.2e-04 1.8e-03 1.7e-02 Scrap disposal-industrial

Co-58 1.7e+01 1.7e+00 8.5e+00 6.2e+01 6.2e-02 6.1e-03 3.1e-02 2.3e-01 Scrap yard

Co-60 5.2e+01 5.1e+00 2.6e+01 1.9e+02 1.9e-01 1.9e-02 9.7e-02 7.1e-01 Scrap yard

Ni-59 4.3e-04 4.8e-05 2.2e-04 1.5e-03 1.6e-06 1.8e-07 8.1e-07 5.7e-06 Scrap yard

Ni-63 3.7e-04 3.2e-05 1.8e-04 1.4e-03 1.4e-06 1.2e-07 6.8e-07 5.2e-06 Scrap yard

Zn-65 1.4e+01 4.2e+00 9.6e+00 4.4e+01 5.2e-02 1.5e-02 3.6e-02 1.6e-01 EAF dust-dump trailer

As-73 1.9e-02 1.0e-03 8.1e-03 7.8e-02 6.9e-05 3.7e-06 3.0e-05 2.9e-04 Scrap disposal-industrial

Se-75 5.5e+00 1.6e+00 3.7e+00 1.7e+01 2.0e-02 5.8e-03 1.4e-02 6.3e-02 EAF dust-dump trailer

Sr-85 7.6e+00 7.5e-01 3.8e+00 2.8e+01 2.8e-02 2.8e-03 1.4e-02 1.0e-01 Scrap yard

Sr-89 6.2e-02 6.3e-03 3.2e-02 2.3e-01 2.3e-04 2.3e-05 1.2e-04 8.5e-04 Scrap yard

Sr-90 4.2e-01 0.0e+00 0.0e+00 1.1e-01 1.6e-03 0.0e+00 0.0e+00 4.1e-04 Leachate-steel slag

Y-91 1.3e-01 1.3e-02 6.8e-02 4.9e-01 4.9e-04 5.0e-05 2.5e-04 1.8e-03 Scrap yard

Zr-93 2.9e-03 3.6e-04 1.6e-03 8.8e-03 1.1e-05 1.3e-06 5.9e-06 3.3e-05 Processing steel slag

Zr-95 1.5e+01 1.5e+00 7.5e+00 5.5e+01 5.5e-02 5.5e-03 2.8e-02 2.0e-01 Scrap yard

Nb-93m 6.2e-04 7.0e-05 3.2e-04 2.2e-03 2.3e-06 2.6e-07 1.2e-06 8.2e-06 Scrap yard

Nb-94 3.0e+01 3.0e+00 1.5e+01 1.1e+02 1.1e-01 1.1e-02 5.6e-02 4.1e-01 Scrap yard

Nb-95 1.2e+01 1.2e+00 6.1e+00 4.4e+01 4.4e-02 4.3e-03 2.2e-02 1.6e-01 Scrap yard

Mo-93 1.9e-01 0.0e+00 0.0e+00 2.2e-01 7.1e-04 0.0e+00 0.0e+00 8.2e-04 Leachate-industrial-scrap

Tc-97 3.3e-01 0.0e+00 0.0e+00 1.5e+00 1.2e-03 0.0e+00 0.0e+00 5.4e-03 Leachate-industrial-scrap

Tc-97m 3.6e-03 2.0e-04 1.6e-03 1.5e-02 1.3e-05 7.2e-07 5.8e-06 5.6e-05 Scrap disposal-industrial

Tc-99 3.1e+00 0.0e+00 0.0e+00 1.4e+01 1.2e-02 0.0e+00 0.0e+00 5.1e-02 Leachate-industrial-scrap

Ru-103 7.1e+00 7.0e-01 3.6e+00 2.6e+01 2.6e-02 2.6e-03 1.3e-02 9.7e-02 Scrap yard

Ru-106 4.1e+00 4.1e-01 2.1e+00 1.5e+01 1.5e-02 1.5e-03 7.7e-03 5.6e-02 Scrap yard

a

 5th percentile to 95th percentile = 90% confidence interval
Recycling and Disposal of Steel Scrap Chapter 3

Table 3.23 Normalized mass-based effective doses to critical groups for steel

Radionuclide

:Sv/y per Bq/g mrem/y per pCi/g

Scenario

Mean

Percentilea

Mean

Percentilea

5th 50th 95th 5th 50th 95th

NUREG-1640 3-106

Ag-108m 2.9e+01 2.8e+00 1.5e+01 1.1e+02 1.1e-01 1.1e-02 5.4e-02 3.9e-01 Scrap yard

Ag-110m 5.2e+01 5.1e+00 2.6e+01 1.9e+02 1.9e-01 1.9e-02 9.7e-02 7.1e-01 Scrap yard

Cd-109 5.5e-02 3.0e-03 2.4e-02 2.3e-01 2.0e-04 1.1e-05 8.8e-05 8.4e-04 Scrap disposal-industrial

Sn-113 3.7e+00 3.7e-01 1.9e+00 1.4e+01 1.4e-02 1.4e-03 7.0e-03 5.1e-02 Scrap yard

Sb-124 3.3e+01 3.3e+00 1.7e+01 1.2e+02 1.2e-01 1.2e-02 6.2e-02 4.6e-01 Scrap yard

Sb-125 7.0e+00 7.0e-01 3.6e+00 2.6e+01 2.6e-02 2.6e-03 1.3e-02 9.6e-02 Scrap yard

Te-123m 1.4e+00 7.4e-02 5.9e-01 5.7e+00 5.1e-03 2.7e-04 2.2e-03 2.1e-02 Scrap disposal-industrial

Te-127m 9.7e-02 2.8e-02 6.6e-02 3.0e-01 3.6e-04 1.0e-04 2.5e-04 1.1e-03 EAF dust-dump trailer

I-125 1.0e+00 3.0e-01 8.9e-01 2.3e+00 3.8e-03 1.1e-03 3.3e-03 8.4e-03 Airborne emissions

I-129 3.3e+02 0.0e+00 0.0e+00 1.1e+03 1.2e+00 0.0e+00 0.0e+00 4.2e+00 Leachate-steel slag

I-131 3.4e+00 1.8e-01 1.4e+00 1.4e+01 1.3e-02 6.5e-04 5.4e-03 5.3e-02 Scrap disposal-industrial

Cs-134 4.1e+01 1.2e+01 2.8e+01 1.3e+02 1.5e-01 4.6e-02 1.0e-01 4.6e-01 EAF dust-dump trailer

Cs-135 8.6e-03 0.0e+00 0.0e+00 0.0e+00 3.2e-05 0.0e+00 0.0e+00 0.0e+00 Leachate-industrial-scrap

Cs-137 1.5e+01 4.6e+00 1.0e+01 4.7e+01 5.6e-02 1.7e-02 3.8e-02 1.7e-01 EAF dust-dump trailer

Ba-133 4.9e+00 4.8e-01 2.5e+00 1.8e+01 1.8e-02 1.8e-03 9.1e-03 6.6e-02 Scrap yard

Ce-139 1.4e+00 7.5e-02 6.0e-01 5.8e+00 5.2e-03 2.8e-04 2.2e-03 2.2e-02 Scrap disposal-industrial

Ce-141 6.5e-01 3.5e-02 2.8e-01 2.7e+00 2.4e-03 1.3e-04 1.0e-03 1.0e-02 Scrap disposal-industrial

Ce-144 9.9e-01 1.0e-01 5.0e-01 3.7e+00 3.7e-03 3.7e-04 1.9e-03 1.4e-02 Scrap yard

Pm-147 1.7e-03 1.9e-04 8.8e-04 6.0e-03 6.2e-06 7.2e-07 3.2e-06 2.2e-05 Scrap yard

Sm-151 1.1e-03 1.4e-04 6.2e-04 3.4e-03 4.2e-06 5.2e-07 2.3e-06 1.3e-05 Processing steel slag

Eu-152 2.2e+01 2.2e+00 1.1e+01 8.0e+01 8.0e-02 8.0e-03 4.1e-02 3.0e-01 Scrap yard

Eu-154 2.1e+01 2.1e+00 1.1e+01 7.9e+01 7.9e-02 7.9e-03 4.0e-02 2.9e-01 Scrap yard

Eu-155 4.0e-01 2.1e-02 1.7e-01 1.7e+00 1.5e-03 7.9e-05 6.4e-04 6.1e-03 Scrap disposal-industrial

Gd-153 5.2e-01 2.8e-02 2.2e-01 2.1e+00 1.9e-03 1.0e-04 8.3e-04 7.9e-03 Scrap disposal-industrial

Tb-160 1.9e+01 1.9e+00 9.9e+00 7.2e+01 7.2e-02 7.1e-03 3.6e-02 2.7e-01 Scrap yard

Tm-170 3.4e-02 1.8e-03 1.5e-02 1.4e-01 1.3e-04 6.7e-06 5.4e-05 5.2e-04 Scrap disposal-industrial

Tm-171 2.3e-03 1.2e-04 1.0e-03 9.6e-03 8.5e-06 4.6e-07 3.7e-06 3.5e-05 Scrap disposal-industrial

Ta-182 2.3e+01 2.3e+00 1.2e+01 8.5e+01 8.5e-02 8.4e-03 4.3e-02 3.2e-01 Scrap yard

W-181 1.6e-01 8.4e-03 6.8e-02 6.5e-01 5.8e-04 3.1e-05 2.5e-04 2.4e-03 Scrap disposal-industrial

W-185 2.0e-03 2.2e-04 1.0e-03 7.3e-03 7.5e-06 8.0e-07 3.8e-06 2.7e-05 Scrap yard

Os-185 1.3e+01 3.8e+00 8.9e+00 4.1e+01 4.9e-02 1.4e-02 3.3e-02 1.5e-01 EAF dust-dump trailer

Ir-192 1.1e+01 1.1e+00 5.6e+00 4.1e+01 4.1e-02 4.1e-03 2.1e-02 1.5e-01 Scrap yard

Tl-204 1.2e-02 1.3e-03 6.3e-03 4.4e-02 4.5e-05 4.8e-06 2.3e-05 1.6e-04 Scrap yard

Pb-210 6.3e+00 2.7e+00 5.9e+00 1.1e+01 2.3e-02 1.0e-02 2.2e-02 4.1e-02 Transferring EAF dust

Bi-207 4.0e+01 1.2e+01 2.7e+01 1.2e+02 1.5e-01 4.5e-02 1.0e-01 4.6e-01 EAF dust-dump trailer

Po-210 2.5e+00 1.2e+00 2.4e+00 4.2e+00 9.2e-03 4.5e-03 8.7e-03 1.6e-02 Transferring EAF dust

Ra-226 3.5e+01 3.6e+00 1.8e+01 1.3e+02 1.3e-01 1.3e-02 6.6e-02 4.8e-01 Scrap yard

Ra-228 1.9e+01 1.9e+00 9.5e+00 6.8e+01 6.9e-02 7.2e-03 3.5e-02 2.5e-01 Scrap yard

a

 5th percentile to 95th percentile = 90% confidence interval
Chapter 3 Recycling and Disposal of Steel Scrap

Table 3.23 Normalized mass-based effective doses to critical groups for steel

Radionuclide

:Sv/y per Bq/g mrem/y per pCi/g

Scenario

Mean

Percentilea

Mean

Percentilea

5th 50th 95th 5th 50th 95th

3-107 NUREG-1640

Ac-227 2.8e+01 3.5e+00 1.5e+01 8.4e+01 1.0e-01 1.3e-02 5.7e-02 3.1e-01 Processing steel slag

Th-228 3.7e+01 4.1e+00 1.9e+01 1.3e+02 1.4e-01 1.5e-02 7.1e-02 4.9e-01 Scrap yard

Th-229 3.2e+01 3.8e+00 1.7e+01 1.1e+02 1.2e-01 1.4e-02 6.2e-02 4.2e-01 Scrap yard

Th-230 1.0e+01 1.2e+00 5.3e+00 3.6e+01 3.8e-02 4.4e-03 2.0e-02 1.3e-01 Scrap yard

Th-232 1.1e+01 1.2e+00 5.6e+00 3.8e+01 4.0e-02 4.6e-03 2.1e-02 1.4e-01 Scrap yard

Pa-231 3.3e+01 3.9e+00 1.8e+01 1.2e+02 1.2e-01 1.4e-02 6.5e-02 4.4e-01 Scrap yard

U-232 1.4e+01 1.7e+00 7.4e+00 4.1e+01 5.0e-02 6.1e-03 2.7e-02 1.5e-01 Processing steel slag

U-233 5.9e+00 0.0e+00 0.0e+00 0.0e+00 2.2e-02 0.0e+00 0.0e+00 0.0e+00 Leachate-industrial-scrap

U-234 4.2e+00 0.0e+00 0.0e+00 0.0e+00 1.5e-02 0.0e+00 0.0e+00 0.0e+00 Leachate-industrial-scrap

U-235 5.1e+00 0.0e+00 0.0e+00 0.0e+00 1.9e-02 0.0e+00 0.0e+00 0.0e+00 Leachate-industrial-scrap

U-236 3.8e+00 0.0e+00 0.0e+00 0.0e+00 1.4e-02 0.0e+00 0.0e+00 0.0e+00 Leachate-industrial-scrap

U-238 3.9e+00 0.0e+00 0.0e+00 0.0e+00 1.5e-02 0.0e+00 0.0e+00 0.0e+00 Leachate-industrial-scrap

Np-237 2.9e+01 0.0e+00 0.0e+00 5.7e+01 1.1e-01 0.0e+00 0.0e+00 2.1e-01 Leachate-industrial-scrap

Pu-236 4.5e+00 5.3e-01 2.4e+00 1.6e+01 1.7e-02 1.9e-03 8.8e-03 6.0e-02 Scrap yard

Pu-238 1.1e+01 1.3e+00 5.7e+00 3.9e+01 4.0e-02 4.7e-03 2.1e-02 1.4e-01 Scrap yard

Pu-239 1.2e+01 1.4e+00 6.3e+00 4.3e+01 4.4e-02 5.1e-03 2.3e-02 1.6e-01 Scrap yard

Pu-240 1.2e+01 1.4e+00 6.3e+00 4.3e+01 4.4e-02 5.1e-03 2.3e-02 1.6e-01 Scrap yard

Pu-241 2.2e-01 2.5e-02 1.1e-01 7.7e-01 8.0e-04 9.3e-05 4.2e-04 2.9e-03 Scrap yard

Pu-242 1.1e+01 1.3e+00 5.9e+00 4.0e+01 4.1e-02 4.8e-03 2.2e-02 1.5e-01 Scrap yard

Pu-244 1.7e+01 2.0e+00 8.9e+00 6.1e+01 6.3e-02 7.6e-03 3.3e-02 2.3e-01 Scrap yard

Am-241 1.1e+01 1.3e+00 5.9e+00 3.2e+01 4.0e-02 4.9e-03 2.2e-02 1.2e-01 Processing steel slag

Am-242m 1.1e+01 1.3e+00 5.9e+00 3.3e+01 4.0e-02 4.9e-03 2.2e-02 1.2e-01 Processing steel slag

Am-243 1.2e+01 1.5e+00 6.6e+00 3.6e+01 4.4e-02 5.4e-03 2.4e-02 1.3e-01 Handling slag

Cm-242 1.3e+00 1.6e-01 6.9e-01 3.8e+00 4.6e-03 5.8e-04 2.6e-03 1.4e-02 Handling slag

Cm-243 8.6e+00 1.1e+00 4.8e+00 2.6e+01 3.2e-02 3.9e-03 1.8e-02 9.7e-02 Handling slag

Cm-244 6.6e+00 7.9e-01 3.7e+00 2.0e+01 2.5e-02 2.9e-03 1.4e-02 7.5e-02 Handling slag

Cm-245 1.1e+01 1.3e+00 6.2e+00 3.4e+01 4.1e-02 5.0e-03 2.3e-02 1.3e-01 Handling slag

Cm-246 1.1e+01 1.3e+00 5.8e+00 3.3e+01 4.0e-02 4.9e-03 2.2e-02 1.2e-01 Processing steel slag

Cm-247 1.4e+01 1.7e+00 7.3e+00 5.0e+01 5.2e-02 6.2e-03 2.7e-02 1.8e-01 Scrap yard

Cm-248 3.8e+01 4.6e+00 2.1e+01 1.1e+02 1.4e-01 1.7e-02 7.6e-02 4.2e-01 Processing steel slag

Bk-249 4.3e-02 5.3e-03 2.3e-02 1.3e-01 1.6e-04 2.0e-05 8.6e-05 4.8e-04 Processing steel slag

Cf-248 2.2e+00 2.7e-01 1.2e+00 6.8e+00 8.3e-03 1.0e-03 4.6e-03 2.5e-02 Handling slag

Cf-249 2.2e+01 2.6e+00 1.1e+01 7.7e+01 8.0e-02 9.5e-03 4.2e-02 2.8e-01 Scrap yard

Cf-250 8.6e+00 1.0e+00 4.8e+00 2.6e+01 3.2e-02 3.8e-03 1.8e-02 9.6e-02 Handling slag

Cf-251 1.9e+01 2.3e+00 1.0e+01 5.7e+01 7.0e-02 8.4e-03 3.9e-02 2.1e-01 Handling slag

Cf-252 5.0e+00 6.0e-01 2.8e+00 1.5e+01 1.8e-02 2.2e-03 1.0e-02 5.6e-02 Handling slag

Cf-254 3.2e+02 3.2e+01 1.6e+02 1.2e+03 1.2e+00 1.2e-01 5.9e-01 4.3e+00 Scrap yard

Es-254 1.9e+01 2.0e+00 9.9e+00 7.1e+01 7.2e-02 7.5e-03 3.7e-02 2.6e-01 Scrap yard

a

 5th percentile to 95th percentile = 90% confidence interval
Recycling and Disposal of Steel Scrap Chapter 3

NUREG-1640 3-108

Table 3.24 Normalized surficial effective doses to critical groups for steel

Radionuclide

:Sv/y per Bq/cm2 mrem/y per pCi/cm2

Scenario

Mean

Percentilea

Mean

Percentilea

5th 50th 95th 5th 50th 95th

H-3 4.0e-03 0.0e+00 2.8e-06 1.5e-02 1.5e-05 0.0e+00 1.0e-08 5.5e-05 Leachate-industrial-scrap

C-14 6.5e-03 0.0e+00 0.0e+00 9.8e-03 2.4e-05 0.0e+00 0.0e+00 3.6e-05 Leachate-industrial-scrap

Na-22 8.3e+00 8.4e-01 4.2e+00 3.0e+01 3.1e-02 3.1e-03 1.6e-02 1.1e-01 Scrap yard

P-32 1.1e-02 1.1e-03 5.6e-03 4.1e-02 4.1e-05 4.0e-06 2.1e-05 1.5e-04 Scrap yard

S-35 1.1e-04 1.2e-05 5.6e-05 3.9e-04 4.0e-07 4.4e-08 2.1e-07 1.5e-06 Scrap yard

Cl-36 3.9e-01 0.0e+00 0.0e+00 1.7e+00 1.4e-03 0.0e+00 0.0e+00 6.1e-03 Leachate-steel slag

K-40 6.7e-01 6.7e-02 3.4e-01 2.4e+00 2.5e-03 2.5e-04 1.2e-03 9.0e-03 Scrap yard

Ca-41 3.5e-02 0.0e+00 0.0e+00 1.5e-01 1.3e-04 0.0e+00 0.0e+00 5.5e-04 Leachate-steel slag

Ca-45 4.1e-04 4.1e-05 2.1e-04 1.5e-03 1.5e-06 1.5e-07 7.8e-07 5.7e-06 Scrap yard

Sc-46 7.3e+00 7.3e-01 3.7e+00 2.7e+01 2.7e-02 2.7e-03 1.4e-02 9.9e-02 Scrap yard

Cr-51 7.0e-02 3.9e-03 3.1e-02 2.9e-01 2.6e-04 1.4e-05 1.1e-04 1.1e-03 Scrap disposal-industrial

Mn-53 1.8e-04 0.0e+00 0.0e+00 0.0e+00 6.5e-07 0.0e+00 0.0e+00 0.0e+00 Leachate-industrial-scrap

Mn-54 3.1e+00 3.1e-01 1.6e+00 1.1e+01 1.2e-02 1.2e-03 5.8e-03 4.2e-02 Scrap yard

Fe-55 1.5e-04 1.2e-05 7.3e-05 5.7e-04 5.5e-07 4.5e-08 2.7e-07 2.1e-06 Scrap yard

Fe-59 4.1e+00 4.1e-01 2.1e+00 1.5e+01 1.5e-02 1.5e-03 7.7e-03 5.6e-02 Scrap yard

Co-56 1.3e+01 1.3e+00 6.7e+00 4.9e+01 4.9e-02 4.9e-03 2.5e-02 1.8e-01 Scrap yard

Co-57 2.2e-01 1.2e-02 9.5e-02 9.1e-01 8.1e-04 4.5e-05 3.5e-04 3.4e-03 Scrap disposal-industrial

Co-58 3.3e+00 3.3e-01 1.7e+00 1.2e+01 1.2e-02 1.2e-03 6.2e-03 4.5e-02 Scrap yard

Co-60 1.0e+01 1.0e+00 5.2e+00 3.7e+01 3.8e-02 3.8e-03 1.9e-02 1.4e-01 Scrap yard

Ni-59 8.5e-05 9.4e-06 4.3e-05 3.1e-04 3.1e-07 3.5e-08 1.6e-07 1.1e-06 Scrap yard

Ni-63 7.3e-05 6.4e-06 3.6e-05 2.8e-04 2.7e-07 2.4e-08 1.3e-07 1.0e-06 Scrap yard

Zn-65 2.8e+00 8.5e-01 1.9e+00 8.2e+00 1.0e-02 3.1e-03 7.0e-03 3.0e-02 EAF dust-dump trailer

As-73 3.7e-03 2.0e-04 1.6e-03 1.5e-02 1.4e-05 7.5e-07 5.9e-06 5.7e-05 Scrap disposal-industrial

Se-75 1.1e+00 3.2e-01 7.3e-01 3.1e+00 4.0e-03 1.2e-03 2.7e-03 1.2e-02 EAF dust-dump trailer

Sr-85 1.5e+00 1.5e-01 7.5e-01 5.5e+00 5.5e-03 5.5e-04 2.8e-03 2.0e-02 Scrap yard

Sr-89 1.2e-02 1.3e-03 6.2e-03 4.5e-02 4.6e-05 4.7e-06 2.3e-05 1.7e-04 Scrap yard

Sr-90 8.8e-02 0.0e+00 0.0e+00 2.2e-02 3.2e-04 0.0e+00 0.0e+00 8.0e-05 Leachate-steel slag

Y-91 2.6e-02 2.7e-03 1.3e-02 9.6e-02 9.8e-05 9.9e-06 4.9e-05 3.6e-04 Scrap yard

Zr-93 5.7e-04 7.0e-05 3.2e-04 1.7e-03 2.1e-06 2.6e-07 1.2e-06 6.5e-06 Processing steel slag

Zr-95 2.9e+00 3.0e-01 1.5e+00 1.1e+01 1.1e-02 1.1e-03 5.5e-03 3.9e-02 Scrap yard

Nb-93m 1.2e-04 1.4e-05 6.4e-05 4.5e-04 4.5e-07 5.1e-08 2.3e-07 1.7e-06 Scrap yard

Nb-94 5.9e+00 6.0e-01 3.0e+00 2.2e+01 2.2e-02 2.2e-03 1.1e-02 8.0e-02 Scrap yard

Nb-95 2.4e+00 2.3e-01 1.2e+00 8.7e+00 8.8e-03 8.6e-04 4.4e-03 3.2e-02 Scrap yard

Mo-93 3.8e-02 0.0e+00 0.0e+00 4.3e-02 1.4e-04 0.0e+00 0.0e+00 1.6e-04 Leachate-industrial-scrap

Tc-97 6.6e-02 0.0e+00 0.0e+00 2.9e-01 2.5e-04 0.0e+00 0.0e+00 1.1e-03 Leachate-industrial-scrap

Tc-97m 7.2e-04 4.0e-05 3.1e-04 3.0e-03 2.7e-06 1.5e-07 1.2e-06 1.1e-05 Scrap disposal-industrial

Tc-99 6.2e-01 0.0e+00 0.0e+00 2.7e+00 2.3e-03 0.0e+00 0.0e+00 1.0e-02 Leachate-industrial-scrap

Ru-103 1.4e+00 1.4e-01 7.0e-01 5.1e+00 5.2e-03 5.1e-04 2.6e-03 1.9e-02 Scrap yard

Ru-106 8.2e-01 8.2e-02 4.1e-01 3.0e+00 3.0e-03 3.0e-04 1.5e-03 1.1e-02 Scrap yard

a

 5th percentile to 95th percentile = 90% confidence interval
Chapter 3 Recycling and Disposal of Steel Scrap

Table 3.24 Normalized surficial effective doses to critical groups for steel

Radionuclide

:Sv/y per Bq/cm2 mrem/y per pCi/cm2

Scenario

Mean

Percentilea

Mean

Percentilea

5th 50th 95th 5th 50th 95th

3-109 NUREG-1640

Ag-108m 5.7e+00 5.7e-01 2.9e+00 2.1e+01 2.1e-02 2.1e-03 1.1e-02 7.6e-02 Scrap yard

Ag-110m 1.0e+01 1.0e+00 5.2e+00 3.7e+01 3.8e-02 3.8e-03 1.9e-02 1.4e-01 Scrap yard

Cd-109 1.1e-02 6.0e-04 4.7e-03 4.5e-02 4.0e-05 2.2e-06 1.7e-05 1.7e-04 Scrap disposal-industrial

Sn-113 7.4e-01 7.4e-02 3.7e-01 2.7e+00 2.7e-03 2.7e-04 1.4e-03 1.0e-02 Scrap yard

Sb-124 6.6e+00 6.6e-01 3.3e+00 2.4e+01 2.4e-02 2.4e-03 1.2e-02 9.0e-02 Scrap yard

Sb-125 1.4e+00 1.4e-01 7.0e-01 5.1e+00 5.2e-03 5.2e-04 2.6e-03 1.9e-02 Scrap yard

Te-123m 2.7e-01 1.5e-02 1.2e-01 1.1e+00 1.0e-03 5.5e-05 4.4e-04 4.2e-03 Scrap disposal-industrial

Te-127m 1.9e-02 5.7e-03 1.3e-02 5.5e-02 7.1e-05 2.1e-05 4.8e-05 2.0e-04 EAF dust-dump trailer

I-125 2.0e-01 6.0e-02 1.8e-01 4.4e-01 7.6e-04 2.2e-04 6.5e-04 1.6e-03 Airborne emissions

I-129 6.4e+01 0.0e+00 0.0e+00 2.3e+02 2.4e-01 0.0e+00 0.0e+00 8.4e-01 Leachate-steel slag

I-131 6.7e-01 3.6e-02 2.9e-01 2.8e+00 2.5e-03 1.3e-04 1.1e-03 1.0e-02 Scrap disposal-industrial

Cs-134 8.0e+00 2.4e+00 5.5e+00 2.4e+01 3.0e-02 9.0e-03 2.0e-02 8.9e-02 EAF dust-dump trailer

Cs-135 1.8e-03 0.0e+00 0.0e+00 0.0e+00 6.6e-06 0.0e+00 0.0e+00 0.0e+00 Leachate-industrial-scrap

Cs-137 3.0e+00 9.0e-01 2.0e+00 8.9e+00 1.1e-02 3.3e-03 7.5e-03 3.3e-02 EAF dust-dump trailer

Ba-133 9.6e-01 9.7e-02 4.9e-01 3.5e+00 3.6e-03 3.6e-04 1.8e-03 1.3e-02 Scrap yard

Ce-139 2.8e-01 1.5e-02 1.2e-01 1.1e+00 1.0e-03 5.6e-05 4.4e-04 4.3e-03 Scrap disposal-industrial

Ce-141 1.3e-01 7.0e-03 5.6e-02 5.3e-01 4.7e-04 2.6e-05 2.1e-04 2.0e-03 Scrap disposal-industrial

Ce-144 2.0e-01 2.0e-02 1.0e-01 7.2e-01 7.3e-04 7.4e-05 3.7e-04 2.7e-03 Scrap yard

Pm-147 3.3e-04 3.9e-05 1.7e-04 1.2e-03 1.2e-06 1.4e-07 6.4e-07 4.5e-06 Scrap yard

Sm-151 2.2e-04 2.7e-05 1.2e-04 6.8e-04 8.2e-07 1.0e-07 4.5e-07 2.5e-06 Processing steel slag

Eu-152 4.3e+00 4.3e-01 2.2e+00 1.6e+01 1.6e-02 1.6e-03 8.0e-03 5.8e-02 Scrap yard

Eu-154 4.2e+00 4.3e-01 2.1e+00 1.5e+01 1.6e-02 1.6e-03 7.9e-03 5.7e-02 Scrap yard

Eu-155 7.8e-02 4.3e-03 3.4e-02 3.3e-01 2.9e-04 1.6e-05 1.3e-04 1.2e-03 Scrap disposal-industrial

Gd-153 1.0e-01 5.6e-03 4.4e-02 4.3e-01 3.8e-04 2.1e-05 1.6e-04 1.6e-03 Scrap disposal-industrial

Tb-160 3.8e+00 3.8e-01 1.9e+00 1.4e+01 1.4e-02 1.4e-03 7.2e-03 5.2e-02 Scrap yard

Tm-170 6.7e-03 3.7e-04 2.9e-03 2.8e-02 2.5e-05 1.4e-06 1.1e-05 1.0e-04 Scrap disposal-industrial

Tm-171 4.5e-04 2.5e-05 2.0e-04 1.9e-03 1.7e-06 9.3e-08 7.3e-07 7.0e-06 Scrap disposal-industrial

Ta-182 4.6e+00 4.6e-01 2.3e+00 1.7e+01 1.7e-02 1.7e-03 8.5e-03 6.2e-02 Scrap yard

W-181 3.1e-02 1.7e-03 1.3e-02 1.3e-01 1.1e-04 6.3e-06 5.0e-05 4.8e-04 Scrap disposal-industrial

W-185 4.0e-04 4.3e-05 2.0e-04 1.4e-03 1.5e-06 1.6e-07 7.5e-07 5.3e-06 Scrap yard

Os-185 2.6e+00 7.7e-01 1.8e+00 7.7e+00 9.7e-03 2.9e-03 6.5e-03 2.8e-02 EAF dust-dump trailer

Ir-192 2.2e+00 2.2e-01 1.1e+00 8.1e+00 8.2e-03 8.2e-04 4.1e-03 3.0e-02 Scrap yard

Tl-204 2.4e-03 2.6e-04 1.2e-03 8.8e-03 8.9e-06 9.6e-07 4.5e-06 3.2e-05 Scrap yard

Pb-210 1.2e+00 5.4e-01 1.2e+00 2.1e+00 4.6e-03 2.0e-03 4.3e-03 7.9e-03 Transferring EAF dust

Bi-207 7.9e+00 2.4e+00 5.4e+00 2.4e+01 2.9e-02 8.9e-03 2.0e-02 8.7e-02 EAF dust-dump trailer

Po-210 4.9e-01 2.5e-01 4.6e-01 8.2e-01 1.8e-03 9.1e-04 1.7e-03 3.0e-03 Transferring EAF dust

Ra-226 6.9e+00 7.1e-01 3.5e+00 2.5e+01 2.6e-02 2.6e-03 1.3e-02 9.4e-02 Scrap yard

Ra-228 3.7e+00 3.9e-01 1.9e+00 1.3e+01 1.4e-02 1.4e-03 6.9e-03 5.0e-02 Scrap yard

a

 5th percentile to 95th percentile = 90% confidence interval
Recycling and Disposal of Steel Scrap Chapter 3

Table 3.24 Normalized surficial effective doses to critical groups for steel

Radionuclide

:Sv/y per Bq/cm2 mrem/y per pCi/cm2

Scenario

Mean

Percentilea

Mean

Percentilea

5th 50th 95th 5th 50th 95th

NUREG-1640 3-110

Ac-227 5.4e+00 6.8e-01 3.0e+00 1.6e+01 2.0e-02 2.5e-03 1.1e-02 6.1e-02 Processing steel slag

Th-228 7.3e+00 8.2e-01 3.7e+00 2.7e+01 2.7e-02 3.0e-03 1.4e-02 9.8e-02 Scrap yard

Th-229 6.4e+00 7.5e-01 3.3e+00 2.3e+01 2.4e-02 2.8e-03 1.2e-02 8.5e-02 Scrap yard

Th-230 2.0e+00 2.3e-01 1.0e+00 7.2e+00 7.4e-03 8.7e-04 3.9e-03 2.7e-02 Scrap yard

Th-232 2.1e+00 2.5e-01 1.1e+00 7.6e+00 7.8e-03 9.2e-04 4.1e-03 2.8e-02 Scrap yard

Pa-231 6.6e+00 7.8e-01 3.5e+00 2.4e+01 2.5e-02 2.9e-03 1.3e-02 8.8e-02 Scrap yard

U-232 2.7e+00 3.2e-01 1.5e+00 8.1e+00 9.8e-03 1.2e-03 5.4e-03 3.0e-02 Processing steel slag

U-233 1.2e+00 0.0e+00 0.0e+00 0.0e+00 4.3e-03 0.0e+00 0.0e+00 0.0e+00 Leachate-industrial-scrap

U-234 8.1e-01 0.0e+00 0.0e+00 0.0e+00 3.0e-03 0.0e+00 0.0e+00 0.0e+00 Leachate-industrial-scrap

U-235 9.9e-01 0.0e+00 0.0e+00 0.0e+00 3.7e-03 0.0e+00 0.0e+00 0.0e+00 Leachate-industrial-scrap

U-236 7.5e-01 0.0e+00 0.0e+00 0.0e+00 2.8e-03 0.0e+00 0.0e+00 0.0e+00 Leachate-industrial-scrap

U-238 7.7e-01 0.0e+00 0.0e+00 0.0e+00 2.8e-03 0.0e+00 0.0e+00 0.0e+00 Leachate-industrial-scrap

Np-237 5.8e+00 0.0e+00 0.0e+00 1.1e+01 2.1e-02 0.0e+00 0.0e+00 4.2e-02 Leachate-industrial-scrap

Pu-236 9.0e-01 1.0e-01 4.7e-01 3.2e+00 3.3e-03 3.9e-04 1.7e-03 1.2e-02 Scrap yard

Pu-238 2.2e+00 2.5e-01 1.1e+00 7.8e+00 8.0e-03 9.3e-04 4.2e-03 2.9e-02 Scrap yard

Pu-239 2.4e+00 2.7e-01 1.2e+00 8.5e+00 8.7e-03 1.0e-03 4.5e-03 3.1e-02 Scrap yard

Pu-240 2.4e+00 2.7e-01 1.2e+00 8.5e+00 8.7e-03 1.0e-03 4.5e-03 3.1e-02 Scrap yard

Pu-241 4.3e-02 5.0e-03 2.2e-02 1.5e-01 1.6e-04 1.8e-05 8.2e-05 5.7e-04 Scrap yard

Pu-242 2.2e+00 2.6e-01 1.2e+00 8.0e+00 8.2e-03 9.5e-04 4.3e-03 3.0e-02 Scrap yard

Pu-244 3.4e+00 4.0e-01 1.8e+00 1.2e+01 1.3e-02 1.5e-03 6.5e-03 4.4e-02 Scrap yard

Am-241 2.1e+00 2.6e-01 1.2e+00 6.5e+00 7.8e-03 9.6e-04 4.3e-03 2.4e-02 Processing steel slag

Am-242m 2.1e+00 2.6e-01 1.2e+00 6.5e+00 7.8e-03 9.6e-04 4.3e-03 2.4e-02 Processing steel slag

Am-243 2.3e+00 2.9e-01 1.3e+00 7.0e+00 8.6e-03 1.1e-03 4.8e-03 2.6e-02 Handling slag

Cm-242 2.5e-01 3.1e-02 1.4e-01 7.5e-01 9.1e-04 1.2e-04 5.1e-04 2.8e-03 Handling slag

Cm-243 1.7e+00 2.1e-01 9.5e-01 5.1e+00 6.3e-03 7.8e-04 3.5e-03 1.9e-02 Handling slag

Cm-244 1.3e+00 1.6e-01 7.3e-01 4.0e+00 4.8e-03 5.9e-04 2.7e-03 1.5e-02 Handling slag

Cm-245 2.2e+00 2.7e-01 1.2e+00 6.6e+00 8.1e-03 9.9e-04 4.5e-03 2.5e-02 Processing steel slag

Cm-246 2.1e+00 2.6e-01 1.2e+00 6.4e+00 7.8e-03 9.5e-04 4.3e-03 2.4e-02 Processing steel slag

Cm-247 2.8e+00 3.3e-01 1.4e+00 9.8e+00 1.0e-02 1.2e-03 5.3e-03 3.6e-02 Scrap yard

Cm-248 7.4e+00 9.1e-01 4.1e+00 2.3e+01 2.7e-02 3.4e-03 1.5e-02 8.4e-02 Processing steel slag

Bk-249 8.4e-03 1.0e-03 4.6e-03 2.6e-02 3.1e-05 3.8e-06 1.7e-05 9.5e-05 Processing steel slag

Cf-248 4.4e-01 5.4e-02 2.5e-01 1.4e+00 1.6e-03 2.0e-04 9.1e-04 5.0e-03 Handling slag

Cf-249 4.3e+00 5.1e-01 2.2e+00 1.5e+01 1.6e-02 1.9e-03 8.3e-03 5.6e-02 Scrap yard

Cf-250 1.7e+00 2.1e-01 9.4e-01 5.2e+00 6.3e-03 7.6e-04 3.5e-03 1.9e-02 Handling slag

Cf-251 3.7e+00 4.6e-01 2.1e+00 1.1e+01 1.4e-02 1.7e-03 7.6e-03 4.2e-02 Processing steel slag

Cf-252 9.8e-01 1.2e-01 5.4e-01 3.0e+00 3.6e-03 4.4e-04 2.0e-03 1.1e-02 Handling slag

Cf-254 6.2e+01 6.3e+00 3.1e+01 2.3e+02 2.3e-01 2.3e-02 1.2e-01 8.5e-01 Scrap yard

Es-254 3.8e+00 4.0e-01 1.9e+00 1.4e+01 1.4e-02 1.5e-03 7.2e-03 5.2e-02 Scrap yard

a

 5th percentile to 95th percentile = 90% confidence interval
Chapter 3 Recycling and Disposal of Steel Scrap

3-111 NUREG-1640

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Yu, C., et al. 2000. “Development of Probabilistic RESRAD 6.0 and RESRAD-BUILD 3.0

Computer Codes,” NUREG/CR-6697, ANL/EAD/TM-98. Washington, DC: U.S. Nuclear

Regulatory Commission.

Yu, C., et al. 2001. “User's Manual for RESRAD Version 6,” ANL/EAD-4. Argonne, IL:

Argonne National Laboratory.
Chapter 4 Recycling and Disposal of Copper Scrap

4-1 NUREG-1640

Assessments have been performed of the potential radiation doses to individuals from the recycling or

disposal of copper scrap that could be cleared from nuclear facilities. The assessment addresses 20

scenarios that depict exposures resulting from the handling and processing of cleared scrap and the

products of melting and refining this scrap at secondary copper producers, emission of airborne

effluents from these facilities, transportation of scrap and furnace products, the use of copper products,

the landfill disposal of cleared scrap and reverberatory furnace slag, and the infiltration of well water by

leachate from landfills containing cleared scrap or slag. The analysis utilizes data on secondary copper

production, as currently practiced in the United States, and on contemporary U.S. work practices and

living habits.

The critical group for the largest number of radionuclides, accounting for over three-fourths of the 115

radionuclides in the analysis, consists of workers handling copper slag at a secondary fire refinery. The

critical group accounting for the second largest number of nuclides comprises workers processing

copper scrap at a scrap yard.

Mean values of mass-based normalized EDEs to critical groups range from a high of 36 :Sv/y per Bq/g

(0.13 mrem/y per pCi/g) from Th-229 to a low of 1.4e-5 :Sv/y per Bq/g (5.0e-8 mrem/y per pCi/g) from

Mn-53. The corresponding surficial EDEs are 69 and 2.6e-5 :Sv/y per Bq/cm2

, respectively. Mean

values of mass-based normalized effective doses range from a high of 8.7 :Sv/y per Bq/g (0.032

mrem/y per pCi/g) from Cf-254 to a low of 6.3e-6 :Sv/y per Bq/g (2.3e-8 mrem/y per pCi/g) from Mn-53. 

The corresponding surficial effective doses are 17 and 1.2e-5 :Sv/y per Bq/cm2

, respectively. The

critical group in all four cases comprises the workers handling copper slag. 

4 RECYCLING AND DISPOSAL OF COPPER SCRAP

This chapter describes the radiological assessment of the recycling and/or disposal of copper

scrap that could be cleared from NRC-licensed facilities. This assessment is based on a realistic

appraisal of current U.S. industrial practices involving the recycling of copper scrap into various

copper products, or of disposing of the scrap in an industrial or municipal landfill. 

4.1 Introduction to Analysis

As was the case with steel, the evaluation of the potential doses from cleared copper scrap

consists of two main parts. The first step is characterizing the flow of cleared scrap through the

normal recycling process, beginning with the generation of scrap, through refining,

manufacturing, and product use, as well as disposal as an alternative to recycling. This enables

the calculation of concentrations of the various radionuclides in products and by-products of the

refining of copper scrap, normalized to an initial concentration of unit specific activity (Bq/g) or

unit areal activity concentration (Bq/cm2

).

The second step is the development and analysis of exposure scenarios. Most of the 20 scenarios

in the copper analysis were modeled on corresponding scenarios for iron and steel scrap. 

Essential differences between the two sets of scenarios are discussed in Section 4.6.

4.2 Flow of Copper Scrap

This section presents an overview of the recycling of copper scrap in the United States. Its

purpose is: (1) to serve as an information source for the radiological assessment, and (2) to
Recycling and Disposal of Copper Scrap Chapter 4

1

 Scrap and refinery products can also be shipped by rail or waterway.

2

 “Reverberatory” refers to the design of the furnace (see Glossary for full explanation of this term). “Fire refining”

refers to the process which typically utilizes this type of furnace. These two descriptive terms are sometimes used

interchangeably in the present chapter.

3

 Another alternative, the processing of scrap at the nuclear facility, is outside the scope the analysis. Such

processing would in most cases be performed by radiation workers whose occupational exposures are controlled under

current regulations. 

NUREG-1640 4-2

present a context for those aspects of the recycling and disposal of copper scrap that are

addressed by this assessment. It thus includes some data which are not directly utilized in our

study.

Figure 4.1 presents a schematic diagram of the flow of copper scrap, as characterized in our

analysis. As is the case for other cleared materials, this is a simplified idealization of the actual

process. The diagram depicts the sequence of steps which are represented by the exposure

scenarios. Intermediate steps, not represented by exposure scenarios, are indicated by dashed

lines or boxes. Other steps and processes are discussed in the following sections of this chapter.

The process begins with the release of cleared scrap from an NRC-licensed facility. It is

assumed that the scrap is shipped by truck1

 to a scrap yard operated by a scrap metal dealer. The

processing performed by this dealer, which can vary with the grade (i.e., type or composition) of

scrap, includes shearing the metal into size, briquetting or crushing thin and lightweight

materials (e.g., turnings and borings), magnetically separating ferrous metals, and cleaning and

degreasing. Insulation removal is required for the recycling of most copper wire. The scrap

dealer then ships the processed scrap to a secondary producer that employs a reverberatory (firerefining) furnace2

 to make finished copper products (e.g., copper tubing). 

Alternatively, the licensee or demolition contractor may elect to dispose of the scrap in an

industrial or municipal solid waste (MSW) landfill.3

 Jolly (1997) has suggested that about onehalf of discarded copper products is sent to landfills or other disposal facilities.

By-products of the reverberatory furnace include slag and offgas. The slag is transported by

truck1

 for disposal in a landfill. (Slag may also be sold to a processor for recovery of copper,

who would ship the residue to a landfill). The offgas consists of the fumes and particulates

evolved during melting which are captured by the facility's emission control system. After

cooling, most of the offgas is collected in the baghouse (or some other air pollution control

device [APCD]) in the form of dust. The dust, like the slag, is transported by truck for disposal

in a landfill. Gases, vapors, and some of the particulates escape the filtration system and are

released to the atmosphere. These airborne effluents may be transported by air currents to a

nearby residence.

Copper produced by secondary refiners is used to make a variety of finished products. The

present analysis examines three such products. Two are generic shapes that can represent a
Chapter 4 Recycling and Disposal of Copper Scrap

4-3 NUREG-1640

Figure 4.1 Flow of copper scrap

number of individual products. In addition, one specific product—copper pipes used in a

domestic water supply system—is included in the assessment.

4.2.1 Sources of Material

As is the case for steel scrap, the main generator of copper scrap addressed in this study is the

nuclear industry, which consists primarily of commercial power plants, test and research

reactors, and industrial nuclear facilities. It has been estimated that a 1,000 Mw(e) PWR power

plant contains about 694 t of copper (plus 25 t of bronze and 10 t of brass) (Bryan and Dudley

1974). As shown in Table A.10 (Appendix A of the present report), a total of 51.5 t of copper is

associated with equipment—reactor plant equipment, fuel storage, and reactor auxiliaries— that

is assumed to be significantly contaminated and not a likely candidate for clearance. Table A.10

further indicates that a total of 580.3 t of copper is associated with non-impacted systems—

electrical plant equipment, miscellaneous equipment, site improvements, intake/discharge, and

miscellaneous buildings. Subtracting the contaminated and the non-impacted metal from the
Recycling and Disposal of Copper Scrap Chapter 4

4

 The much smaller quantities of bronze and brass are not addressed by the main analysis; however, they are

included in the scoping analysis of a large brass musical instrument cited in Section 4.6.9.

5

 American Wire Gauge, also known as Brown & Sharpe gauge.

6

 The terms “smelting,” “melting,” and “refining” are used loosely and often interchangeably by the nonferrous

metals industry. Strictly speaking, smelting refers to the reduction of ores or scrap with a significant nonmetallic content,

melting (also “casting” or “founding”) is changing the shape but not the chemical form of the material, and refining refers

to chemical purification. Brass production can involve all three processes and is often generically referred to as

“smelting.” Technical terms specific to the metals industry are defined in the Glossary.

NUREG-1640 4-4

total copper inventory yields a balance of 62 t of material that would be a potential candidate for

clearance. Much of this scrap would be high quality unalloyed copper from copper wire, cable,

and bus bar. It is assumed that this relatively small quantity of scrap would be cleared during a

single year.4

A discussion of the mass-to-surface ratios of the copper components of a nuclear power plant is

presented in Section A.6.3. The data in that section describe all of the copper components, while

the parameter required for the present analysis is the average of the components likely to be

cleared. A probability distribution of mass-to-surface ratios of the cleared scrap was determined

as follows. As stated in Section A.6.3, most of the copper is assumed to be in the form of singleor multi-stranded wire, the remainder being in the form of busbars. The individual strands are

assumed to range from 8 to 14 AWG.5

 The probability distribution was generated by a Monte

Carlo sampling of the gauge of the copper wire, assuming that all even-number gauges from 8 to

14 were equally probable. The total mass of copper was divided by the sum of the surface areas

of the individual strands of wire plus the surface areas of the busbars to yield a mass-to-surface

ratio of copper scrap. The results of 10,000 Monte Carlo simulations have a mean value of

0.52 g/cm2

 and a coefficient of variation of 8.3%.

4.2.2 Recycling of Copper Scrap

Copper scrap typically accounts for about one-half of the total amount of copper consumed in the

United States. From 1975 through 1995, scrap has accounted for 44% to 54.7% of total copper

consumption (“Trends in U.S. Copper . . . ” 1997). As cited in the same source, copper products

have long lives, ranging from 10 to 100 years or more. The average product life, and hence the

average age of old or post-consumer scrap, has been estimated to be about 20 years (Jolly 1997). 

In contrast, new scrap may have a 30-day turnaround. Unalloyed copper scrap is commonly

smelted, or smelted and refined, while brass and bronze scrap (the largest source of coppercontaining scrap) is remelted for use in mill products with little refining.6

 As stated in Section

4.2.1, copper scrap from a nuclear power plant will primarily be in the form of unalloyed copper.

In its annual survey of copper, the U.S. Geological Survey provides data on the sources of

copper-bearing scrap. Table 4.1 presents data on the quantities of copper recovered from

copper-base alloys in 2000. As shown in this table, about 73% of recycled copper was recovered

from new scrap, the balance from old scrap. About 81% of recycled copper was recovered in
Chapter 4 Recycling and Disposal of Copper Scrap

4-5 NUREG-1640

brass and bronze, most of the balance being in the form of unalloyed copper. A breakdown of

copper recovery by type of processing operation is shown in Table 4.2. 

Since the copper scrap from nuclear power reactors would be old, unalloyed scrap, the rest of

this discussion will focus on scrap of that form. Edelstein (2002, Table 10) provides the

following gross weights for consumption of unalloyed copper scrap in 2000:

• Smelters, refiners, and ingot makers ....... 219,000 t

• Brass and wire rod mills ................ 452,000 t

• Foundries and miscellaneous manufacturers . . 48,800 t

Table 4.1 Copper recovered from copper-base scrap in 2000

Recovery Amount (t) Fraction

From new scrap 906,000 73.1%

From old scrap 334,000 26.9%

Total recovery by type of scrap 1,240,000 100.0%

As unalloyed copper

at electrolytic plants 128,000 10.3%

at other plants 88,400 7.1%

Subtotal 217,000 17.5%

In brass and bronze 1,010,000 81.5%

In chemical compounds 11,700 0.9%

Total recovery by form 1,240,000 100.0%

Source: Edelstein 2002, Table 6.

Note: Data are rounded to no more than three significant figures; may not add to totals shown.

Table 4.2 Copper recovered from copper-base scrap by type of operation in 2000

Type of operation From new scrap From old scrap Total

Amount (t) Fractiona Amount (t) Fractiona Amount (t) Fractiona

Ingot makers 29,900 3.3% 90,700 27.2% 121,000 9.8%

Refineriesb 39,000 4.3% 169,000 50.6% 208,000 16.8%

Brass & wire rod mills 822,000 90.7% 22,200 6.6% 844,000 68.1%

Foundries & manufacturers 10,800 1.2% 44,500 13.3% 55,400 4.5%

Chemical plantsc 3,880 0.4% 7,840 2.3% 11,700 0.9%

Total 906,000 73.1%d 334,000 26.9%d 1,240,000 100.0%

Source: Edelstein 2002, Table 7.

Note: Data are rounded to three significant figures, may not add to totals shown.

a Fraction of total of each column

b Amounts of electrolytically refined and fire-refined scrap based on source of material at smelter level. c Includes copper sulfate and other copper compounds.

d Total new scrap and total old scrap as fraction of total scrap
Recycling and Disposal of Copper Scrap Chapter 4

NUREG-1640 4-6

Our estimates of the recovery from unalloyed copper scrap in 2000, listed in Table 4.3, are based

on the following assumptions: (1) the consumption of unalloyed scrap cited by Edelstein (2002,

Table 10) is equated to the net recovery of copper from copper-base scrap; (2) "miscellaneous

manufacturers" in the cited data includes chemical plants; (3) the ratio of new-to-old unalloyed

scrap for each type of operation is equal to the ratio of all new-to-old copper-based scrap for the

same type of operation, as listed in Table 4.2. Since refiners use only unalloyed scrap, the total

amount of unalloyed scrap recovered by ingot makers is estimated by subtracting the amount of

copper recovered from copper-base scrap by refiners (208 kt) from the total amount of unalloyed

scrap consumed by “smelters, refiners, and ingot makers” (219 kt). 

The data in Table 4.3 show that about 74% of old, unalloyed scrap—the principal form of copper

scrap that would be generated by the dismantlement of nuclear power plants—was consumed by

refiners in 2000 (169 kt ÷ 227 kt = 0.744). Table 4.4 lists the amounts of unalloyed copper

products made from scrap in 2000. Of the total of 208 kt of such products made by electrolytic

and fire refineries, the fire refineries accounted for 80 kt or 38.5%. Thus, fire refiners are

estimated to have consumed 28.6% of old, unalloyed scrap in 2000, the base year for the present

analysis (0.744 × 0.385 = 0.286).

Table 4.3 Unalloyed copper and total copper recovered from copper-base alloys in 2000 (t)

Type of operation All copper-base

scrapa

Unalloyed scrap

New

Old

Total

Amount Fraction

Ingot makers 121,000 2,700 8,300 3.7% 11,000

Refineries (including smelters) 208,000 39,000 169,000 74.4% 208,000

Brass and wire rod mills 844,000 440,000 12,000 5.3% 452,000

Foundries, manufacturers, chemical plants 67,100 10,700 38,100 16.8% 48,800

Total 1,240,000 492,000 227,000 100.0% 720,000

a

 From Table 4.2

Note: Data are rounded to three significant figures; totals may differ due to rounding.

Table 4.4 Unalloyed copper products made from scrap in 2000

Item produced from scrap Amount (t) Fraction

Electrolytically refined copper 128,000 59.2%

Fire-refined copper 80,000 37.0%

Copper powder 7,510 3.5%

Copper castings 839 0.4%

Total 216,349 100.0%

Source: Edelstein (2002, Table 8)
Chapter 4 Recycling and Disposal of Copper Scrap

4-7 NUREG-1640Figure 4.2 Operations in the primary and secondary production of copper
Recycling and Disposal of Copper Scrap Chapter 4

7

 A reverberatory furnace used to produce anodes for electrorefining may be referred to as an “anode furnace,” as in

the flow diagram depicted in Figure 4.2.

NUREG-1640 4-8

4.2.3 Copper Refining

Copper scrap can enter copper refining and processing operations in a variety of ways,

depending on factors such as the quality of the scrap and its alloy content. Some copper scrap is

refined by primary producers and some by secondary processors. Copper and copper-alloy scrap

can also be remelted at brass mills, ingot makers, or foundries.

Primary producers mainly recover copper from ores by smelting or leaching, while secondary

producers recover copper from scrap. Some of the unit operations that are involved in primary

and secondary copper production are illustrated in Figure 4.2. As shown in the diagram, lowgrade copper scrap can be charged to the flash smelter. Some No. 1 and No. 2 scrap (the highest

grades of scrap, which constitute most of the copper scrap generated during the dismantling of a

nuclear power plant) can also be charged to the anode furnace.7 No. 1 scrap can be charged to a

vertical shaft furnace where it would be melted into ingots or other copper products. Secondary

producers can smelt low-grade copper scrap. In addition, a fire-refining furnace, which can be

part of a secondary smelting operation or a free-standing facility, can consume No. 1 and No. 2

scrap. This is a simplified presentation of a complex process which does not attempt to capture

all the flow paths and processing steps of the various products and by-products of copper

refining and production. Details of the process may differ among different facilities.

In 2000, as noted in Table 4.2, approximately 51% of old copper-base scrap was consumed by

smelters and refineries, 7% by brass and wire rod mills, 27% by brass and bronze ingot makers,

and the remainder by miscellaneous manufacturers, foundries, and chemical plants. At the end

of 2000, there were four primary smelters, one secondary smelter, four electrolytic refineries and

four fire refineries operating in the United States (USGS 2001). (The only operating secondary

smelter shut down in October 2001.) In addition there were 35 brass mills, 15 wire rod mills,

and 600 foundries consuming refined copper and direct melt scrap. Brass mills primarily use

new scrap while copper refiners primarily use old scrap.

4.2.3.1 Fire Refining 

Fire refining is typically performed in a reverberatory furnace. This furnace is charged by

forklift trucks or by charging machines. Impurities are removed by oxidizing the molten metal

with air or oxygen and skimming away the resultant slag. The oxygen content of the melt is then

reduced to the desired level (e.g., 0.03% to 0.04%) by adding a hydrocarbon source (e.g., natural

gas or green logs ). The refined copper is cast into shapes such as cakes, billets, or wire bar. 

In some cases, melting of copper scrap in a reverberatory furnace may be the only step in the

refining process. At one copper tubing manufacturer—Reading Tube Corporation—No. 1

copper scrap is the sole feed. All of the incoming scrap is visually inspected for known forms of

suspect copper. An in-depth visual inspection is made of selected samples from the scrap;
Chapter 4 Recycling and Disposal of Copper Scrap

8

 Since about 25% of the melt remains in the furnace as a heel for the subsequent heat, the net output is 135 t. 

9

 George Burg, Vice-President, Manufacturing, Reading Tube Corporation, private communication with William C.

Thurber, SC&A, Inc., May 5, 1999.

4-9 NUREG-1640

chemical analyses are taken from samples to screen for impurities. Typically, scrap inventories

equal one or two days of consumption, but on some occasions may reach five days. The scrap is

charged into a 180-t reverberatory furnace, melted, and blown with air or oxygen to oxidize

impurities.8 The oxide slag is skimmed from the melt. The melt is then covered with charcoal

and “poled” to remove oxygen. In the poling process, green hardwood logs are thrust into the

molten copper bath, where the hydrocarbons react with the oxygen to form CO/CO2. The molten

copper is then laundered. In this process, the copper flows under charcoal into a ladle which is

covered with a carbon-based product. The laundering removes additional oxygen from the melt. 

Final deoxidation is promoted by the addition of phosphorus; the melt is then cast into billets for

subsequent fabrication into tubing.9

 About 30% of the copper in the billets is recycled as home

scrap.

At Reading Tube, slag is skimmed from the furnace through a door at one end, using steel rakes

which are about 3 – 4 m long. Two operators work together with a single rake to skim the slag

into a box beneath the furnace door. Slagging takes about two hours, during which time the

operators are about 2.5 m from the furnace wall. The steel slag boxes are about 1 m square and

0.3 m deep. One of the furnace operators transports the filled slag box via forklift truck to a

temporary storage area, where it is dumped onto the floor. When the slag has cooled, it is broken

up with a “thumper” (air hammer) and metallic copper is culled from the slag by hand. The

culled slag is moved with a front-end loader to an outside storage bin. This slag, which contains

30% to 35% copper, is sold to an outside processor for recovery of additional copper content. 

Offgas from the furnace passes through an after-burner to convert CO to CO2 and to destroy any

hydrocarbons; it is then exhausted through a stack. Stack emissions are monitored for total

particulates, opacity, and SO2. 

The furnace operates on a 24-hour cycle, comprising the following operations:

• Charging . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.5 h

• Melting ................................. 4.5 h

• Refining and slagging . . . . . . . . . . . . . . . . . . . . . 5.5 h

• Poling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.5 h

• Casting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 h

Slag production in a reverberatory furnace varies as a function of the percentage of copper in the

charge. With increasing copper grade (Biswas and Davenport 1976):

• Copper concentration in slag increases

• Slag weight decreases

• Copper loss decreases
Recycling and Disposal of Copper Scrap Chapter 4

10 The terms “electrolytic refining” and “electrorefining” are used interchangeably.

11 According to U.S. patent 4,351,705, a typical slimes composition is 5-10% Cu, 4-8% Ni, 6-8% Sb, 15-25% Sn,

5-12% Pb, 0-2% Ag, and 4-8% As. Smaller quantities of other metals are presumably not listed. 

12 Davenport (1986) states that As, Bi, Co, Fe, Ni, and Sb report to the electrolyte. This characterization of arsenic

conflicts with the information in Footnote 11, as well with the results of our own analysis of the behavior of arsenic

during electrorefining.

NUREG-1640 4-10

4.2.3.2 Electrolytic Refining

The final stage in copper purification employs an electrolytic refining10 process that yields

copper which may contain less than 40 ppm of metallic impurities (Ramachandran and Wildman

1987). During electrorefining, copper anodes and pure copper cathode starter sheets are

suspended in a CuSO4-H2SO4-H2O electrolyte, through which an electrical current is passed at a

potential of about 0.25 Vdc. The process requires 10 to 14 days to produce a cathode weighing

about 150 kg. During electrolysis, the copper dissolves from the anode and deposits on the

cathode. Impurities such as Au, Ag, and other precious metals, as well as Pb, Se, and Te, all of

which are carried over from copper ore, collect in the anode slimes.11 These anode slimes are

collected and sent to a precious metals refinery (Davenport 1986). Other elements, such as Fe,

Ni, and Zn, dissolve in the electrolyte12 and are removed from the copper electrolysis cells in a

bleed stream. The bleed stream is sent to “liberator” cells, where the solution is again

electrolyzed and soluble copper is plated out on insoluble lead anodes. The bleed stream is then

treated for NiSO4 recovery by concentrating the solution in evaporator vessels, where NiSO4

crystals precipitate. The remaining liquor is called “black acid.” Both the NiSO4 and the black

acid may be salable products (Kusik and Kenahan 1978). 

Brunson and Stone (1976) estimate that about 15 lb of slimes are generated for each ton of

copper that is electrorefined (7.5 kg/t). Over a period of years, the slimes content at the refinery

described by these authors has varied from 10 to 19 lb per ton (5 – 9.5 kg/t), depending on the

anode purity (Stone and Tuggle 1995). 

The Amarillo Copper Refinery of ASARCO, Incorporated, the reference electrolytic refinery for

the present analysis, has an annual production of 420 kt of electrolytically refined copper. Fire

refining is conducted in a 320-t reverberatory furnace with an annual output of 114 kt of anodes. 

The normal furnace feed is 81% blister copper from primary producers and 19% No. 2 copper

scrap (Ramachandran and Wildman 1987). The combined output from the reverberatory furnace

and the anode scrap-melting furnace, a total of 240 kt/y, together with 245 kt/y of purchased

anodes, is electrorefined. About 63 kt of spent anodes are recycled to the anode melting furnace. 

Sulfuric acid recovered from the electrolyte bleed circuit is most likely used for electrolyte

makeup; accordingly, it is returned to the process. The nickel sulfate, containing 5% H2SO4 and

3% H2O, is sold to nickel producers for metal recovery. The nickel sulfate also contains

contaminants, such as iron and zinc.
Chapter 4 Recycling and Disposal of Copper Scrap

13 Gates, risers, and sprues are passages in the casting mold which facilitate transport of molten metal to the mold

cavity. Metal which freezes in the passages is recovered and returned to the casting process as home scrap. Pigged cold

metal is excess metal from the furnace charge which is not required for the particular furnace run and is cast into small

ingots (pigs) for subsequent remelting.

4-11 NUREG-1640

4.2.3.3 Brass and Bronze Smelting

There is no significant refining of the metal during the melting of scrap to produce brass and

bronze. Chemical species with high vapor pressures would most likely be volatilized, but the

slag-metal reactions typical of fire-refining operations are not likely to occur to a significant

degree. According to Licht (2000), remelting of bronze using good practices results in total

emissions not exceeding 0.5% of the process weight. However, with brasses containing 15% to

40% Zn, emissions may vary from less than 0.5% to 6% or more of the total mass of metal. As

Licht further notes: 

In brass foundries, as much as 98% of the particulate matter contained in the furnace stack

gases may be zinc oxide and lead oxide, depending on the composition of the alloy. 

Constituents of fumes included zinc, lead, tin, copper, cadmium, silicon, and carbon. They

are present in varying amounts depending on the composition of the alloy and foundry

practice.

Larger foundries that melt brasses and bronzes to produce castings typically use induction

furnaces, while smaller foundries may use fuel-fired crucible furnaces (Licht 2000). Ingot

makers may use reverberatory furnaces (Anigstein et al. 2001, Appendix C). Pacific

Environmental Services (PES 1977, Table 4.5) measured the emissions from 18 shops that melt

brass and bronze in induction furnaces without emissions control equipment. Emissions ranged

from 0.3 to 20 kg/t, with an average value of 10 kg/t. The emissions from six shops which used

baghouses for dust collection ranged from 0.01 to 0.65 kg/t, with an average of 0.35 kg/t. The

report does not state the basis for measurement, but elsewhere in the document emissions are

cited relative to quantities of feed material processed rather than amount of product. 

Consequently, it is assumed here that the units of measurement for emissions from brass

induction furnaces are kilograms per tonne of feed.

It has been estimated that a well run brass foundry has a 53.8% yield of metal in good, finished

castings. Most of the 46.2% loss is recoverable as home scrap (St. John 1958, pp. 88-96). 

Recoverable home scrap includes, at a minimum, gates, risers, and sprues (33.6%), pigged cold

metal (2.0%), reject castings (2.4%), and machine turnings (6.1%).13 Losses which are not fully

recoverable include melting loss, skim and furnace spill, pouring loss, and sand blasting and

grinding loss. For a well run foundry, these net losses are about 2.1%, although they could be as

high as 12.1% for a poorly run shop, where the product yield could be as low as 27.5%.

Detailed information on furnace sizes used for brass and bronze melting was not found during

the course of this study. Edelstein (2002) estimates that refined copper and direct-melt scrap was

consumed in 600 foundries, chemical plants, and miscellaneous operations in 2000. In 2000,

these facilities consumed 125 kt of brass and bronze ingot, 59.8 kt of refined copper, and 83 kt of
Recycling and Disposal of Copper Scrap Chapter 4

14 The total metal content includes, in addition to copper, any alloying elements such as zinc in brass or tin in

bronze.

NUREG-1640 4-12

copper scrap (Edelstein 2002, Table 12). Based on these data, it is estimated that the average

annual consumption of copper-base metals was about 450 t per facility.

4.2.4 Product Use

In addition to the refined metal, by-products of the copper refining operations also have

commercial uses. Both types of products are described in this section.

4.2.4.1 Metal Products

The Copper Development Association (CDA) divides the end-use markets for copper and brass

into five major areas. CDA (2001, Table 4) presents the annual compilation of market data for

2000, listing the following quantities of copper consumed, in millions of pounds (metric tons in

parentheses):

• Building construction (building wire, plumbing and heating, air conditioning and commercial

refrigeration, builders hardware, architectural) ........................ 3,740 (1,696 kt)

• Electrical and electronic products (power utilities, telecommunications, business electronics,

lighting and wiring devices) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2,636 (1,196 kt)

• Industrial machinery and equipment (in-plant equipment, industrial valves and fittings, nonelectrical instruments, off-highway vehicles, heat exchangers) . . . . . . . . . . . . 1,010 (458 kt)

• Transportation equipment (automotive, truck and bus, marine, railroad, aircraft and

aerospace) ..................................................... 1,095 (497 kt)

• Consumer and general products (appliances, cord sets, military and commercial ordnance,

consumer electronics, fasteners and closures, coinage, utensils and cutlery, miscellaneous)

.............................................................. 1,070 (485 kt)

Of the total consumption of 9,551 million pounds (4,332 kt), all but 490 million pounds (222 kt)

was from domestic production. It should be noted that the consumption figures are based on

total metal content,14 not copper content.

CDA 2001 also presents annual consumption data based on types of end products. Summary

statistics for 2000 are listed below, in millions of pounds:

• Wire mill products .............................................. 4,608 (2,090 kt)

• Other mill products (sheet, tube, pipe, rod, bar, etc.) ................... 4,022 (1,824 kt)

• Foundry products .................................................. 385 (175 kt)
Chapter 4 Recycling and Disposal of Copper Scrap

4-13 NUREG-1640

• Powder products . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46 (21 kt)

It can be seen from this summary that, in 2000, wire mill products accounted for 51% of all

domestic copper-bearing products and other mill products accounted for 44% of the total. A

further breakdown of these two categories is provided below, in millions of pounds:

Wire mill products:

• Bare wire . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 370 (168 kt)

• Telecommunications cable . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 675 (306 kt)

• Electronic cable and wire . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 300 (136 kt)

• Building wire . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1,433 (650 kt)

• Magnet wire . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 800 (363 kt)

• Power cable . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 320 (145 kt)

• Apparatus wire and cordage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 245 (111 kt)

• Automotive wire and cable (except magnet wire) . . . . . . . . . . . . . . . . . . . . . . . . . 395 (179 kt)

• Other insulated wire and cable . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70 (32 kt)

Other mill products (percentage refers to the fraction comprising unalloyed copper, the balance

being copper alloys):

• Strip, sheet, plate, and foil (38%) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1,425 (646 kt)

• Mechanical wire (22%) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 99 (45 kt)

• Rod and bar (20%) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1,248 (566 kt)

• Plumbing tube and pipe (100%) ...................................... 675 (306 kt)

• Commercial tube and pipe (94%) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 575 (261 kt)

The following amounts of copper are found in various finished vehicular products (ICA n/d):

• Mid-sized automobile . . . . . . . . . . . . . . . 22.5 kg (including 18 kg of electrical components)

• Typical diesel-electric locomotive . . . . . . . . . . . . . 5,000 kg (large diesel-electric: 7,200 kg)

• Triton-class nuclear submarine . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 90,000 kg

• Average motorized farm vehicle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28 kg

• Average construction vehicle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30 kg

• Electric forklift . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62 kg

• Electrically powered subway car, trolley, or bus . . . . . . . . . . . . . . . . . . . . . . . . 280 – 4,100 kg

4.2.4.2 Refinery By-products

One of the by-products of copper refining operations that may have commercial value is the

zinc-containing dusts used in fertilizers. On July 24, 2002, EPA (2002) promulgated regulations

regarding manufacture of zinc fertilizers from hazardous secondary materials. Because of

certain provisions of the new rule, EPA expected that fertilizer manufacturers would begin to use

“zinc-rich dusts from brass foundries and fabricators as substitutes for other feedstocks [e.g.,

baghouse dust from steelmaking EAFs].” EPA estimated that 23 brass fume generators (ingot

makers, mills, and foundries) would potentially be affected by the new rule.
Recycling and Disposal of Copper Scrap Chapter 4

15 See Footnote 9 on page 4-9.

NUREG-1640 4-14

Another potentially valuable by-product is slag, which contains 30% to 35% copper. As cited in

Section 4.2.3.1, this material may be sold to a specialty processor for metal recovery. 

4.3 Mass Fractions and Partitioning Factors for Refining Operations

For the purpose of the present analysis, the material entering a fire-refining reverberatory furnace

is distributed into three process streams: metal product, slag, and offgas. The offgas consists of

gases and vapors as well as particulates. The particulates and the vapors that condense upon

cooling form dust, a portion of which is captured by the baghouse filters or other APCD. The

volatile fraction, as well as the particulates that escape the baghouse, are released to the

atmosphere. Any impurities (e.g., radionuclides) in the scrap metal are likewise distributed

among the metal, slag, dust, and volatile effluent emissions.

During electrorefining the incoming material, including any impurities, is distributed among the

metal product, the anode slimes, and the electrolyte bleed.

Very limited information is available in the literature to describe mass fractions of materials

produced during brass smelting operations. Slag-metal separations for various elements, which

occur during the fire refining of copper, would most likely not occur during brass smelting,

where the primary objective is to melt the scrap, not to adjust its composition. Airborne

emissions of volatile chemical species can be assumed to be similar to those from a reverberatory

furnace.

As shown in Table 4.2, about 22 kt of copper was recovered from old copper-base scrap at brass

and wire rod mills in 2000. This represents about 2.6% of the 844 kt of copper recovered from

scrap at these facilities, the remainder being from new scrap. Likewise, as shown in Table 4.2,

only 6.6% of the copper from old scrap is recovered at brass and wire rod mills. Both statistics

indicate that brass production does not play a significant role in the recycling of old copper

scrap, such as the scrap that would be cleared from a nuclear facility. Consequently, a more

detailed analysis of mass fractions and partitioning factors in brass and bronze smelting was not

performed for the current assessment. A scoping analysis was performed, however, to determine

if the radiological impacts of cleared scrap processed at such facilities could exceed the impacts

from processes that were studied in greater detail. This analysis is discussed briefly in Section

4.6.9 and in greater detail in Appendix N.

4.3.1 Mass Fractions

4.3.1.1 Fire Refining

The weight of slag produced by the reverberatory furnace of the Reading Tube Corporation is

estimated to be about 2% to 2.5% of the charge weight.15 On this basis, the mass fraction of slag
Chapter 4 Recycling and Disposal of Copper Scrap

16 “PM-10" is the acronym for particulate matter with AMAD  10 :m.

17 Bill Rismiller (Environmental Manager, Reading Tube Division of Cambridge-Lee Industries), private

communication to William C. Thurber, SC&A, Inc. (September 3, 2002).

4-15 NUREG-1640

with respect to scrap charged to the fire-refining furnace was assigned a uniform distribution of

0.020 – 0.025. The slag contains about 40% copper.15

EPA 1995 (Table 12.9-1) lists particulate emission factors for a reverberatory furnace used in the

secondary smelting of unalloyed copper. The factor for total particulates is 2.6 kg of per tonne

of scrap melted, while that for PM-10 emissions16 is 2.5 kg/t. A baghouse reduces the total

emissions to 0.2 kg/t. This is 8% of the unfiltered emissions, implying a baghouse efficiency of

92%. 

The factor for unfiltered total emissions is based on PES 1977 and is the average of 12 plants,

with a range of 0.4 to 15 kg/t. In the present analysis, the mass fraction of dust with respect to

scrap charged to the furnace was assigned a truncated lognormal distribution that is consistent

with these statistics. The distribution has an arithmetic mean of 0.0026, an arithmetic standard

deviation of 0.002855, a minimum of 0.0004, and a maximum of 0.015.

Reading Tube, which uses an APCD other than a baghouse to control particulate emissions,

reports PM-10 emissions corresponding to 0.05 kg per tonne of copper produced.17 These

emissions are about one-fourth of the average total emissions of facilities equipped with

baghouses, indicating that, in this instance, the APCD is at least as efficient as a baghouse. Dust

collected in these APCDs is shipped off site for recovery of its metal content.

For the purpose of the present analysis, the quantity of metallic copper produced from one

furnace heat was calculated by subtracting the amounts of chemically bound copper in the slag

and in the dust (i.e., the amount of copper in the form of CuO), from the amount of metal in the

furnace charge. Gößling (2001) cites a value of 45.04% Cu2O in slag from a fire-refining anode

furnace at a primary copper smelter, which corresponds to a Cu content of 40.00%. This is in

agreement with the estimate for the Reading facility; however, it should be noted that Gößling

describes a somewhat different process. The dust is assumed to contain 75% Cu, in the form of

CuO. The calculation results in yields of 97.9% –99.2%.

4.3.1.2 Electrolytic Refining

As discussed in Section 4.6.8, detailed probabilistic analyses are not performed on exposure

scenarios involving electrolytic refineries. The deterministic scoping analyses described in that

section require only point values rather than probability distributions.

A mass fraction of 0.0075 of anode slimes with respect to the metal fed to the electrorefining

process is adopted for the scoping analyses, based on the data quoted by Brunson and Stone

(1976), as cited in Section 4.2.3.2. Data on the production of nickel sulfate was presented by

Anigstein et al. (2001, Section C.5.1.4), who estimate that ASARCO’s Amarillo Copper
Recycling and Disposal of Copper Scrap Chapter 4

NUREG-1640 4-16

Refinery, which consumes 485 kt/y of copper anodes, would produce about 1,200 t/y of crude

nickel sulfate. This value is adopted for the scoping analyses in the present study.

4.3.2 Partitioning Factors

4.3.2.1 Fire Refining

During fire refining, impurities (elements or chemical compounds) partition between the two

liquid phases—slag and molten metal—or discharge from the furnace in the offgas. Some of the

chemical species that leave the furnace in the offgas remain in the vapor phase while some

condense or coalesce into particulates (dust). Impurities found in coarse particulates are

captured by the baghouse filter or other APCD. Some of the fine particles and the species in the

vapor phase escape in the effluent emissions from the stack. 

The partitioning factors developed for the present analysis are intended to represent the expected

behavior of impurities during melting in a typical reverberatory furnace. Thermodynamic

calculations of the oxidation potential of each element were used in estimating partitioning

factors at temperatures typical of reverberatory furnace operation. The calculations were

supplemented with other data, such as vapor pressures of the chemical species and observed

partitioning based on industry experience and laboratory testing. In the absence of other

information, partitioning factors are estimated, based on the behavior of chemically similar

elements. 

Table 4.5 shows partitioning factors for each element (or its compounds) in fire refining. The

development of statistical distributions for each of these factors is described in Section J.5.

4.3.2.2 Electrolytic Refining

During electrorefining, copper preferentially plates out at the cathode while many impurities,

such as lead and tin, are left in the anode slimes. Nickel and other metallic impurities

accumulate in the electrolyte and are removed in the electrolyte bleed. Extremely low

concentrations of many impurities may be difficult to remove from the copper.

Electrode half-cell potentials were used to establish partitioning during electrorefining. Details

of the partitioning analyses are presented in Appendix J. 

Partitioning factors for electrorefining are presented in Table 4.6.

4.4 Mixing of Cleared Scrap

The concentration of each radionuclide in cleared copper scrap would be reduced by mixing with

other materials, including scrap from other sources, prior to smelting. Further mixing occurs

during the disposal of refinery by-products. The mixing of cleared scrap and of the products

resulting from the refining of the scrap are briefly discussed in this section. The type of mixing

factor used in each exposure scenario is listed in Table 4.7.
Chapter 4 Recycling and Disposal of Copper Scrap

4-17 NUREG-1640

Table 4.5 Partitioning in fire refining of copper (%)

Elements Metal

product Dust Slag Volatile

H, C 0 0 0 100

Na, Ca, Sc, Cr, Sr, Y, Zr, Nb, Mo, Tc, Ba, Ce, 

Pm, Sm, Eu, Gd, Tb, Tm, Ta, W, Ra 0.05–0.15 0 99.85–99.95 0

P, S, K 0.05–0.15 10–90 9.85–89.95 0

Cl, I 0 0–10 90–100 0

Mn 2–5 0 95–98 0

Fe 2–25 0 75–98 0

Co, Ni 1–60 0 40–99 0

Zn, Cd 1–26 0–5 74–94 0

As 10–20 10–80 10–70 0

Se, Te, Cs 10–20 80–90 0 0

Ru, Ag, Os, Ir 100 0 0 0

Sn 12–40 0 60–88 0

Sb 1–69 0–5 31–94 0

Tl 10–20 30–60 20–60 0

Pb 6–100 0–5 0–89 0

Bi 90–100 0–10 0 0

Po 1–50 50–99 0 0

Ac, Np, Pu, Am, Cm, Bk, Cf, Es 0.1–1 0 99–99.9 0

Th, Pa, U 0.1–2 0 98–99.9 0

As discussed in Section 4.6, the only melting or refining process subjected to a detailed analysis

is fire refining at a secondary producer. Consequently, mixing factors for electrorefining and

brass smelting are not presented in this chapter.

4.4.1 Processing Copper Scrap at Scrap Yard

The cleared scrap would be processed at a facility specializing in nonferrous metals. As

discussed in Section D.3.1, the mean throughput of such facilities is about 11 kt/y. The average

mixing factor of cleared copper scrap, as reflected by the mean value of 10,000 Monte Carlo

realizations, is about 5.6 × 10-3.

4.4.2 Secondary Fire Refining

As stated in Section 4.2.3, there were four fire refineries operating in the United States at the end

of 2000. The scrap consumption rate of each of these facilities was estimated on the basis of its

production capacity and the mass fraction of the copper product. The facility is selected at

random, weighted by its capacity. As discussed in greater detail in Section D.3.2, the amount of

cleared scrap includes probabilistically weighted amounts of copper scrap from multiple nuclear

power plants undergoing dismantlement during the same year. The results of 10,000 Monte
Recycling and Disposal of Copper Scrap Chapter 4

18 Because of the skewness of this distribution, the standard error of the mean is a more meaningful metric than the

coefficient of variation.

NUREG-1640 4-18

Carlo realizations of mixing factors have a mean value of 1.1 × 10-3, with a standard error of the

mean of ±7.3 × 10-6.

18

Table 4.6 Partitioning in electrorefining of copper (%)

Elements Copper

cathodes

Anode

slimes

Electrolyte

bleed

Na, K, Sc, Cr, Sr, Y, Zr, Nb, Mo, Tc, Cd, Cs,

Ce, Pm, Sm, Eu, Gd, Tb, Tm, Ta, W, Tl, Ra, 

Ac, Th, Pa, U, Np, Pu, Am, Cm, Bk, Cf, Es

0 0 100

P, As 0.1–2 98–99.9 0

S, Se 0.1–0.2 99.8–99.9 0

Cl, I 0 100 0

Ca 0 40–60 40–60

Mn, Fe 1–3 26–46 51–73

Co 0.5–1.5 0 98.5–99.5

Ni 0.3–0.7 0–10 89.7–99.3

Zn 0 0–10 90–100

Ru 3–4 26–32 65–70

Ag 2–6 94–98 0

Sn 0.1–10 90–99.9 0

Sb 0.1–1 0–74.9 25–99

Te 0–33 67–100 0

Ba 0 1–99 1–99

Os, Ir 0 81–84 16–19

Pb 0.15–0.45 99.55–99.85 0

Bi 0.3–1.4 0–74.7 25–98.6

Po 25–75 25–75 0

4.5 Radionuclide Concentrations in Various Media

The refining process redistributes any impurities (such as radionuclides) in the scrap among the

various furnace products. As discussed in Section 4.4, this partitioning is dependent on the

chemical element in question and applies to all isotopes of that element. 

The annual-average radionuclide concentrations in fire-refined copper and in the by-products of

the fire refining of copper scrap, as well as the annual activity of each nuclide released to the

atmosphere, are calculating by applying the equations listed in Section 3.5.1. The parameters

specific to copper are based on the information presented in this chapter. The values adopted for

the present analysis are listed in Tables B.4 and B.5. 
Chapter 4 Recycling and Disposal of Copper Scrap

19 All parameter values that are specific to the copper exposure scenarios are listed in Table B.9. All other

parameters have the values listed for the steel scenarios in Table B.8.

4-19 NUREG-1640

The mean and the 5th, 50th and 95th percentile radionuclide concentrations in the products of

fire refining of copper scrap, as well as the annual activities released to the atmosphere, are listed

in Appendix K. 

4.6 Dose Assessment of Copper Recycling and Disposal Scenarios

The 20 exposure scenarios included in the copper analysis, along with the environmental

transport pathways included in each scenario, are listed in Table 4.7. The basis of each scenario

is listed in the column headed “CA” (corresponding analysis). Each of the 14 scenarios

indicated by the notation “Fe” is based on the corresponding scenario in the steel analysis, which

has the same or a similar title. Five other scenarios, indicated by the notation “mod,” are based

on similar steel scenarios, but with significant modifications. In addition, there is one new

product use scenario: individuals consuming drinking water from copper pipes. Only those

aspects of the analysis that are new or significantly different from the corresponding steel

analyses are discussed in this section.19

4.6.1 Inhalation and Inadvertent Ingestion of Copper Dusts

The U.S. Occupational Safety and Health Administration (OSHA) limits the workplace exposure

to copper dusts. The permissible exposure limit (PEL) for copper mists and dusts is 1 mg/m3

 of

Cu (29 CFR 1910.1000, Table Z-1). As stipulated by 29 CFR 1910.1000(a)(2): An employee's

exposure . . . shall not exceed the Time Weighted Average [(TWA)] given for that substance any

8-hour work shift of a 40-hour work week. The incorporation of these limits into the copper

scenarios is discussed in the following sections.

4.6.2 Scrap Processing, and Handling of Fire-refined Copper Product

The workers processing copper scrap at a scrap yard would be exposed to copper dust generated

by the shredding and sectioning of copper scrap. Because the OSHA limit applies to any given

8-hour shift, the annual average dust loading would be significantly less than the limit. The

8-hour TWA dust concentration is modeled as a truncated lognormal distribution, with a range of

zero to 1 mg/m3

 of Cu and a mean of 0.5 mg/m3. A similar model is applied to the copper

product handling scenario.
Recycling and Disposal of Copper Scrap Chapter 4

NUREG-1640 4-20

Table 4.7 Scenario and exposure pathway matrix

Scenario abbreviation Scenario title CAa MFb Pathwaysc

Extd Inh Ing

Handling and Processing

Scrap yard Processing copper scrap at scrap yard mod SD 20 ! !

Handling metal product Handling fire-refined copper product Fe AA 23 ! !

Handling slag Handling copper slag at fire-refining facility Fe AA 21 ! !

Baghouse maintenance Reverberatory furnace baghouse maintenance Fe AA 22

Atmospheric Release

Airborne emissions Emission of airborne effluents from furnace Fe AA F2 ! !

Transport

Scrap truck–driver Truck driver hauling cleared copper scrap mod N 26

Metal product–driver Truck driver hauling fire-refined copper mod AA 29

Slag truck–driver Truck driver hauling reverberatory furnace slag Fe AA 28 ! !

Dust truck–driver Truck driver hauling reverberatory furnace dust Fe AA 27 ! !

Product Use

Exposure to small mass Exposure to small mass of fire-refined copper Fe AA 24

Copper object on body Small fire-refined copper object on body Fe AA 25

Drinking–copper pipes Drinking tapwater from copper pipes new AA !

Landfill Disposal

Scrap disposal–industrial Handling copper scrap at industrial landfill Fe IL F1

Scrap disposal–municipal Handling copper scrap at municipal landfill Fe ML F1

Slag disposal–industrial Handling copper slag at industrial landfill Fe IL F1 ! !

Slag disposal–municipal Handling copper slag at municipal landfill Fe ML F1 ! !

Groundwater Contaminated by Leachate from Landfills

Leachate–industrial–scrap Leachate from industrial landfill–scrap Fe IL !

Leachate–municipal–scrap Leachate from municipal landfill–scrap Fe ML !

Leachate–industrial–dross Leachate from industrial landfill–slag mod IL !

Leachate–municipal–dross Leachate from municipal landfill–slag mod ML ! a CA = corresponding analysis: Fe = steel, mod = modified from corresponding steel analysis b MF = mixing factor: AA = annual average, IL = industrial landfill, ML = municipal landfill, N = no mixing, SD = scrap dealer (see

text—details in Appendix D) c Exposure pathways: Ext = external, Inh = inhalation, Ing = ingestion of food, water, or soil; inadvertent ingestion d External exposure dose factors:

20 Scrap pile

21 Slag pile

22 Baghouse

23 Large metal mass

24 Small metal mass

25 Small object on body

26 Scrap truck

27 Dust truck

28 Slag truck

29 Truck loaded with metal product

F1 Federal Guidance Report # 12: soil contaminated to an infinite depth

F2 Federal Guidance Report # 12: contaminated ground surface
Chapter 4 Recycling and Disposal of Copper Scrap

4-21 NUREG-1640

Because of the controls required to maintain the dust concentrations within acceptable limits, it

is likely that the ingestion of copper dust would also be reduced from that in the corresponding

steel scenarios. Since the airborne dust concentration limit of 1 mg/m3

 is one-fifth of the

5 mg/m3

 PEL on the respirable fraction of nuisance dusts, it is reasonable to assume that the

inadvertent ingestion of dust would be reduced by a similar amount. This is likely to occur

because the protective measures used to reduce inhalation exposure would also reduce the oral

intake, either by reducing the opportunity for ingestion through the use of respiratory apparatus,

or by reducing the amount of finely divided copper in the worker’s immediate environment. 

Exposure durations of less than eight hours per shift would permit the worker to be exposed to

proportionately higher dust concentrations. The doses from internal exposure are calculated to

be the same as if the worker were exposed for eight hours to the lower concentration. External

exposures are based on the time the worker actually spends on this task.

4.6.3 Handling Copper Slag at Fire Refinery

The slag handling scenario at a secondary copper fire refinery is based on a description of this

operation presented by Anigstein et al. (2001, Section 9.3.3). After being skimmed from the

molten copper and allowed to cool, the slag is transported to a corner of the building, where it is

spread on the floor. A worker breaks up the slag with a pneumatic hammer and culls copper

nuggets by hand. This worker would be externally exposed to direct, penetrating radiation from

any residual radionuclides that partition to the slag.

The worker would also be exposed to the inhalation of the dust that would be generated during

this operation. The inhalation exposure would be limited by the OSHA limit on copper dust. 

Since Cu comprises 40% of reverberatory furnace slag, the 8-hour TWA limit on slag dust would

be 2.5 mg/m3

 (1 mg/m3 ÷ 0.4 = 2.5). The dust loading is assigned a lognormal distribution, such

that the 8-hour TWA would range from zero to 2.5 mg/m3 of slag, with a mean of 1.25 mg/m3. 

As stated earlier, exposure durations of less than eight hours per shift would allow the worker to

be exposed to proportionately higher dust concentrations. The doses from the inhalation

exposure are calculated to be the same as if the worker were exposed for eight hours to the lower

concentration. 

Because the worker typically spends about two hours per day on this task, the actual dust

concentrations could be significantly higher; therefore, the rate of inadvertent ingestion is

assumed to be the same as in the corresponding steel scenarios.

4.6.4 Atmospheric Releases During Fire refining

The only significant difference in the atmospheric release scenario for the fire refining of copper

scrap and the comparable scenario for melt-refining of steel scrap is the period of buildup of

radionuclides in the soil at the receptor location. In the steel scenario, it was assumed that the

activity would build up over a period of 1.7 years, the assumed period of time during which steel

scrap would be cleared from a commercial nuclear power plant undergoing dismantlement. 

Because of the large number of steelmaking facilities which consume iron and steel scrap, it is
Recycling and Disposal of Copper Scrap Chapter 4

NUREG-1640 4-22

4.1

unlikely that a single melt shop would be recycling scrap from more than one nuclear power

reactor. However, the secondary copper industry includes only four fire refineries. 

Consequently, there is a high likelihood that, if copper cleared from the nuclear plants is destined

for recycling, the same refinery would be recycling such scrap in different years. The buildup

time was calculated as follows:

tb = buildup time of activity in soil (d)

ffr = fraction of Cu scrap consumed by fire-refining furnaces

mCu = mass of Cu scrap cleared during dismantlement of one reactor

mfr = annual capacity of given fire-refining facility

nd = days per year

NR = number of reactors scheduled for dismantlement

m0 = mass of cleared Cu scrap processed by given fire-refining facility in one year

Mfr = combined capacity of all U.S. fire-refining facilities

The numerator of the first term in Equation 4.1 represents the total mass of cleared copper

scrap—generated by the dismantlement of all nuclear power reactors scheduled for

dismantlement over the next 50 years—that would be processed by all currently operating firerefining facilities. The denominator represents the mass of cleared scrap processed by the given

fire-refining facility in one year. The term in brackets is the ratio of the production capacity of

the given facility to that of all such facilities. The expression is thus the nominal time period

during which a given fire-refining facility would be processing cleared scrap, assuming the same

amount of cleared scrap was processed each year. 

Because the models used to calculate doses from the deposition of airborne effluent emissions on

soil incorporate a single buildup period, the recycling of cleared scrap at a given facility is

assumed to take place over a contiguous period of time. This could lead to a slightly

conservative assessment.

4.6.5 Transportation Scenarios

The distances traveled in transporting copper scrap and the by-products of copper refining are

based on data for shipments of “Metallic waste and scrap” presented by the Bureau of the Census

(1999). These distances are represented by a normal distribution, with a mode of 130 mi (209

km), the average distance listed by the Census Bureau, and a coefficient of variation of 11.6%, as

given by the Census Bureau. The lower end of the distribution was truncated at 50 mi (80 km),

based on engineering judgement—50 mi at an average speed of 50 mph (80 km/h) results in an

average exposure time of one hour. Although shorter trips are possible, the time spent loading

and unloading would make it unlikely that a driver would spend less than one hour per load. The
Chapter 4 Recycling and Disposal of Copper Scrap

4-23 NUREG-1640

4.2

average speed of all trips made by a given driver is represented by a triangular distribution with a

range of 40 to 60 mph (64 – 97 km/h), and a mode of 50 mph. These speeds are based on

engineering judgement and are intended to span the range of average highway speeds throughout

the United States. 

Because of the small quantity of cleared copper scrap, it is assumed that it would all be

transported by one driver, unlike the case for steel scrap discussed in Chapter 3.

The distances traveled by copper products shipped from the refinery are based on shipments of

“Nonferrous metal, except precious, in unwrought forms, in finished basic shapes” (Bureau of

the Census 1999). These distances are represented by a truncated lognormal distribution, with an

arithmetic mean of 393 mi (632 km), the average distance listed by the Census Bureau, and a

coefficient of variation of 10.2%, as given by the Census Bureau. The minimum and maximum

are set to 50 and 2,000 mi (80 – 3,200 km), based on engineering judgement. Because nonferrous metal products are typically shipped over greater distances than iron and steel products, it

is more likely that a truck equipped with a sleeping compartment would be used for this purpose. 

The calculation of the duration of external exposure in the sleeper is the same as that presented

under the sub-heading “Truck Driver Hauling EAF Dust in a Dump Trailer” in Section 3.7.3.3.

4.6.6 Drinking Tapwater from Copper Pipes

The one entirely new scenario is the use of copper piping made of recycled scrap. Some of the

metal, along with any radionuclides from the cleared scrap that partition to the fire-refined metal

product, gradually dissolves in the water passing through these pipes. This material would be

ingested by individuals drinking tapwater carried by these pipes. Copper piping is one of the

major products made from fire-refined copper scrap. 

4.6.6.1 Exposure Pathways

The only pathway included in this scenario is the ingestion of radionuclides dissolved in the

drinking water. Airborne suspension of particulates from copper piping is unlikely; therefore,

the inhalation pathway is not included. Also, the doses from external exposure to copper pipes

and fixtures were judged to be small compared to the doses from the ingestion of drinking water;

therefore, that pathway was not included in the model.

4.6.6.2 Detailed Description

In common with other product-use scenarios, the exposure assessment spans a one-year period

after the plumbing is installed and put into use. The gradual dissolution of the piping is assumed

to produce a constant concentration of copper in the tapwater. The dose from the drinking water

pathway is expressed as follows:
Recycling and Disposal of Copper Scrap Chapter 4

NUREG-1640 4-24

Diw = dose from ingestion of radionuclide i in tapwater during assessment period (:Sv)

CCu = concentration of copper in tapwater (g/mL)

Cip = undecayed specific activity of radionuclide i in copper product (see Equation 3.2)

(Bq/g)

Fig = dose conversion factor for ingestion of radionuclide i (:Sv/Bq) 

Iw = daily consumption of tapwater (mL/d)

tys = exposure duration (d)

ts = time from clearance of material to the time the scenario begins (d)

i = radioactive decay rate of nuclide i (d-1)

ta = assessment period

Equation 4.2 expresses the assumption that any radionuclides that partitioned to the copper

during fire refining would dissolve in the tapwater at the same relative rate as the copper.

Therefore, the activity concentration of a given nuclide in the water is the product of the

concentration of copper in the water and the specific activity of the nuclide in the copper. 

In most cases, the scenario begins at the time the copper pipes are installed and put into use. For

those nuclides with long-lived progenies, the beginning of the assessment period is adjusted

incrementally over the average service life of the copper pipes until the peak year—the 365.25-

day period which results in the highest dose—is determined. 

4.6.6.3 Concentration of Copper in Tapwater

The Agency for Toxic Substances and Disease Registry (ATSDR 1990) has reported that the use

of copper or bronze pipes increases the concentration of copper in drinking water. When water

is allowed to remain in the pipes for a period of time, copper can leach from the pipes into the

water. Soft water is more corrosive than hard water, enhancing leaching of copper from the

pipes. When pipes have not been flushed after a period of disuse, the concentration of copper in

tap water may exceed 1.3 ppm (1.3 mg Cu/L), which is the EPA drinking-water limit. The report

presents results from a number of different studies. One study found that the copper

concentration in treated water in Canada that has not been exposed to copper pipes was generally

very low:  10 ppb ( 10 :g Cu/L). Another study showed the mean copper concentrations in

running and standing water from copper pipes in Seattle to be 0.16 and 0.45 ppm, respectively,

with an average value of 0.31 ppm (0.31 mg/L). The increase in copper concentration due to

leaching of copper from the pipes was 0.3 mg/L. A triangular distribution, with a minimum of

0.16 mg/L, a mode of 0.3 mg/L, and a maximum of 1.3 mg/L was therefore assigned to the

parameter CCu in Equation 4.2.
Chapter 4 Recycling and Disposal of Copper Scrap

20 Harry Tallert, Tank House Manager, Amarillo Copper Refinery, ASARCO Incorporated, private communication

with William C. Thurber, SC&A, Inc., March 7, 2003.

4-25 NUREG-1640

4.6.7 Well Water Infiltrated by Leachate from Landfills Containing Copper Slag

The exposures of residents drinking water from wells down gradient from landfills used for the

disposal of copper slag were patterned after similar scenarios involving the disposal of BOF dust

in the steel analysis.

4.6.8 Electrolytic Refineries

Only exposure scenarios involving the fire refining of copper scrap are subjected to detailed,

probabilistic analyses. Electrolytic refineries and brass mills were excluded because it is highly

unlikely that the processing of copper scrap from nuclear facilities by these producers would lead

to higher normalized doses than would result from fire refining by secondary producers.

As shown in Figure 4.2, high-grade (No. 1 and No. 2) copper scrap, the type that would be

generated during the dismantlement of a nuclear power plant, can be introduced into the firerefining anode furnace at an electrolytic refinery. The processes employed at this furnace are

essentially the same as the free-standing fire refinery already modeled; consequently, no

additional analyses of these processes are needed. The electrolytic plant uses these and other

fire-refined anodes and further purifies the copper. Consequently, the metal product contains

fewer impurities, and would thus result in lesser impacts from any impurities entering the firerefining stage.

The same statement may not apply to the by-products of electrorefining: the anode slimes and

the electrolyte bleed. Because of the small mass fractions of these waste streams, any impurities

that remained in the anodes following fire refining but were removed during electrorefining

would be concentrated in one of these two media. Anigstein et al. (2001, Chapter 9) analyzed

the external exposure of a tank house operator to -emitting radionuclides that were concentrated

in the anode slimes. A scoping analysis patterned on this scenario shows that it is unlikely that

this scenario would give rise to the critical group for any radionuclide in the present study. (The

scoping analyses discussed in this and the following section are described in Appendix N of the

present report.)

The process of recovering crude nickel sulfate from the electrolyte bleed is reasonably

automated, requiring little “up-close and personal attention.”20 Scoping analyses were performed

on two workers that could be exposed to radionuclides that concentrate in the nickel sulfate: a

forklift operator that transports the filled bags of concentrate and a truck driver that transports

the concentrate to a processor for recovery of nickel and other valuable metals. In neither case

would such a scenario give rise to a critical group.

Figure 4.2 also indicates that No. 1 scrap can be introduced into the cathode furnace. Since this

is a melting rather than a refining furnace, there would be little removal of any residual
Recycling and Disposal of Copper Scrap Chapter 4

NUREG-1640 4-26

impurities in this scrap. A scoping analysis was performed of the exposure of a worker handling

the metal product of this furnace. The results show that this scenario does not lead to a critical

group.

4.6.9 Brass Mills

As was discussed in Section 4.2.3.3, scrap melted in brass mills undergoes little or no refining;

consequently, any impurities in the scrap most likely remain in the metal. A scoping analysis

was performed to determine if individuals playing large brass musical instruments made with

cleared copper scrap could constitute a critical group. The results of the scoping analysis show

that this is not the case.

4.6.10 Scenario Timing

This section discusses the time periods for each of the copper exposure scenarios. The timing is

based on data specific to the copper industry, supplemented by engineering judgment.

4.6.10.1 Scrap Transport and Handling

• Cleared scrap is transported to a scrap dealer or to a landfill. Transportation takes two to six

days from the time of clearance.

• The scrap is disposed of in a landfill one to seven days after arrival.

• The scrap is processed and remains at the scrap dealer for a period of one to 30 days after it

arrives.

4.6.10.2 Refining and Processing

• The fire-refining process and associated operations at the secondary producer take place one

to five days after the scrap is shipped from the scrap dealer.

• Airborne effluent releases from the reverberatory furnace occur at the time the scrap is

melted and refined.

• Slag and dust are produced at the time the scrap is refined.

4.6.10.3 Transportation of Products of Fire Refining

• Transport of fire-refined copper occurs three to 30 days after production.

• Dust from the reverberatory furnace is collected monthly and may be sent to a third party for

metal recovery. Transportation is assumed to take place 30 to 60 days after the dust is

generated.
Chapter 4 Recycling and Disposal of Copper Scrap

21 As discussed in Chapter 1, the group which receives the highest mean normalized EDE from a given radionuclide

is defined as the EDE-critical group for that nuclide.

4-27 NUREG-1640

• Slag may also be sent to a third party for metal recovery. Transportation is assumed to take

place two to three days after the slag is generated.

4.6.10.4 Use of Copper Products

• Manufactured items are put into use 10 to 60 days after the refined copper is shipped from

the secondary producer. As noted in Section 4.2.2, the average life of copper products is 20

years.

• Copper pipes are installed and put into service between 10 and 270 days after shipment from

the secondary producer. This range encompasses replacement plumbing, which might be

installed and used as soon as 10 days after shipment, and pipes installed in a new building

under construction, which might not be used until nine months later. The average service life

of copper pipes is 35 years (Henstock 1997).

4.7 Dose Assessments of Recycling and Disposal of Copper Scrap

As discussed in previous sections of this chapter, the radiological assessment of the clearance of

copper scrap from NRC-licensed nuclear facilities evaluates the radiation exposures of

individual members of various groups to each of 115 radionuclides and their progenies in 20

exposure scenarios. 

4.7.1 Calculation of Effective Dose Equivalents (EDEs)

The groups described by five of these scenarios receive the highest mean normalized EDEs from

one year of exposure to cleared copper scrap from all 115 nuclides, one scenario constituting the

EDE-critical group for 90 nuclides.21 Table 4.9 lists the mean and the 5th, 50th, and 95th

percentile mass-based normalized EDEs from each radionuclide to its respective critical group,

while Table 4.10 lists the corresponding surficial EDEs. Figure 4.3 lists the scenarios describing

the EDE-critical groups and displays the number of radionuclides for which each scenario

constitutes the critical group. The mean and the 5th, 50th, 90th, and 95th percentile normalized

EDEs from all 115 nuclides for all 20 scenarios are tabulated in Appendix G-1.

The scenario giving rise to a critical group for the greatest number of radionuclides comprises

workers handling and processing copper slag from a reverberatory furnace at a secondary

refinery. The small mass fraction of the reverberatory furnace slag, combined with the

significant partitioning of a large majority of radionuclides to the slag, results in very high

concentrations of these nuclides in slag relative to their original concentrations in scrap. The

slag handling scenario exposes the workers to a large, flat area of slag with no external shielding

and little self-shielding, enhancing the external exposures to direct penetrating radiation emitted
Recycling and Disposal of Copper Scrap Chapter 4

NUREG-1640 4-28

Figure 4.3 Scenarios giving rise to EDE-critical groups for copper

by those nuclides. These workers are also subjected to internal exposures from inhalation and

ingestion of the slag dust generated during this operation. 

Workers handling and processing copper scrap at a scrap yard constitute the critical group for 17

nuclides. The factors contributing to the exposures of these workers are discussed in Section

3.9.1. Seven of the remaining critical groups stem from the disposal of copper scrap in an

industrial landfill as an alternative to recycling. These critical groups comprise either nearby

residents drinking water from wells contaminated by leachate or workers at the landfill.

4.7.2 Calculation of Effective Doses

The groups described by the same five scenarios characterizing the EDE-critical groups receive

the highest mean normalized effective doses from one year of exposure to cleared copper scrap

from all 115 nuclides, the workers handling and processing copper slag constituting the critical

group for 86 nuclides. Table 4.11 lists the mean and the 5th, 50th, and 95th percentile massbased normalized effective doses from each radionuclide to its respective critical group, while

Table 4.12 lists the corresponding surficial effective doses. Figure 4.4 lists the scenarios

describing the effective dose-critical groups and displays the number of radionuclides for which

each scenario constitutes the critical group. The mean and the 5th, 50th, 90th, and 95th

percentile normalized effective doses from all 115 nuclides for all 20 scenarios are tabulated in

Appendix G-2. The factors leading to the highest effective doses in these scenarios are similar to

those giving rise to the EDE-critical groups discussed in Section 4.7.1.
Chapter 4 Recycling and Disposal of Copper Scrap

4-29 NUREG-1640

Figure 4.4 Scenarios giving rise to effective-dose critical groups for copper

In the case of one radionuclide—Mo-93—the mean normalized effective dose in the critical

group is higher than the 90th percentile effective dose, as listed in Table 4.8. The critical group

for this nuclide comprises persons living down gradient from an industrial landfill used for the

disposal of cleared copper scrap. (The 90th percentile effective dose is in fact zero, which

indicates that, in at least 90% of the Monte Carlo realizations, the activity never reached the well

during the 1,000 year assessment period.) The group with the highest EDE for which the mean

does not exceed the 90th percentile might be considered as an alternate critical group for that

nuclide. This potential alternate critical group is also listed in the table for purposes of

comparison.

Table 4.8 Mass-based normalized effective dose from Mo-93 (:Sv/y per Bq/g)

Nuclidea Critical groupb Potential alternate critical groupc

Mean 90th %-ile Mean 90th %-ile Scenario name

Mo-93 1.2e-03 0.0e+00 4.2e-04 8.7e-04 Handling slag

a Nuclide for which mean normalized effective dose exceeds 90th percentile effective dose

b Critical group = persons living down gradient from an industrial landfill used for the disposal of cleared copper scrap c Group with maximum mean effective dose which does not exceed 90th percentile effective dose to that group
Recycling and Disposal of Copper Scrap Chapter 4

NUREG-1640 4-30

Table 4.9 Normalized mass-based effective dose equivalents to critical groups for copper

Radionuclide

:Sv/y per Bq/g mrem/y per pCi/g

Scenario

Mean

Percentilea

Mean

Percentilea

5th 50th 95th 5th 50th 95th

H-3 1.0e-04 0.0e+00 7.6e-08 4.2e-04 3.7e-07 0.0e+00 2.8e-10 1.6e-06 Leachate-industrial-scrap

C-14 2.4e-04 7.5e-05 1.8e-04 6.1e-04 9.0e-07 2.8e-07 6.7e-07 2.3e-06 Airborne emissions

Na-22 1.2e+00 4.1e-01 9.7e-01 2.5e+00 4.3e-03 1.5e-03 3.6e-03 9.4e-03 Handling slag

P-32 7.9e-04 1.2e-04 4.7e-04 2.6e-03 2.9e-06 4.6e-07 1.7e-06 9.5e-06 Scrap yard

S-35 2.7e-05 5.7e-06 2.0e-05 7.2e-05 1.0e-07 2.1e-08 7.6e-08 2.7e-07 Handling slag

Cl-36 2.1e-03 0.0e+00 0.0e+00 8.1e-03 7.6e-06 0.0e+00 0.0e+00 3.0e-05 Leachate-industrial-scrap

K-40 6.5e-02 1.4e-02 4.1e-02 2.0e-01 2.4e-04 5.2e-05 1.5e-04 7.3e-04 Scrap yard

Ca-41 1.1e-03 0.0e+00 0.0e+00 4.8e-03 4.2e-06 0.0e+00 0.0e+00 1.8e-05 Leachate-industrial-scrap

Ca-45 2.2e-04 6.4e-05 1.8e-04 5.2e-04 8.2e-07 2.4e-07 6.5e-07 1.9e-06 Handling slag

Sc-46 9.3e-01 3.2e-01 7.7e-01 2.1e+00 3.5e-03 1.2e-03 2.8e-03 7.6e-03 Handling slag

Cr-51 8.2e-03 2.4e-03 6.5e-03 1.9e-02 3.0e-05 9.0e-06 2.4e-05 7.2e-05 Handling slag

Mn-53 1.4e-05 4.2e-06 1.1e-05 3.1e-05 5.0e-08 1.6e-08 4.0e-08 1.2e-07 Handling slag

Mn-54 4.3e-01 1.5e-01 3.6e-01 9.5e-01 1.6e-03 5.6e-04 1.3e-03 3.5e-03 Handling slag

Fe-55 4.3e-05 1.3e-05 3.4e-05 1.0e-04 1.6e-07 4.6e-08 1.3e-07 3.8e-07 Handling slag

Fe-59 4.4e-01 1.4e-01 3.5e-01 9.8e-01 1.6e-03 5.3e-04 1.3e-03 3.6e-03 Handling slag

Co-56 1.3e+00 4.2e-01 1.0e+00 2.9e+00 4.8e-03 1.6e-03 3.9e-03 1.1e-02 Handling slag

Co-57 1.5e-02 5.0e-03 1.2e-02 3.3e-02 5.5e-05 1.8e-05 4.5e-05 1.2e-04 Handling slag

Co-58 3.5e-01 1.2e-01 2.9e-01 7.9e-01 1.3e-03 4.3e-04 1.1e-03 2.9e-03 Handling slag

Co-60 1.1e+00 3.8e-01 9.2e-01 2.5e+00 4.2e-03 1.4e-03 3.4e-03 9.2e-03 Handling slag

Ni-59 2.8e-05 9.1e-06 2.2e-05 6.2e-05 1.0e-07 3.4e-08 8.3e-08 2.3e-07 Handling slag

Ni-63 5.4e-05 1.6e-05 4.3e-05 1.3e-04 2.0e-07 5.9e-08 1.6e-07 4.7e-07 Handling slag

Zn-65 2.7e-01 9.5e-02 2.3e-01 6.0e-01 1.0e-03 3.5e-04 8.4e-04 2.2e-03 Handling slag

As-73 1.7e-04 6.5e-06 5.1e-05 5.6e-04 6.2e-07 2.4e-08 1.9e-07 2.1e-06 Scrap disposal-industrial

Se-75 6.5e-02 1.4e-02 4.1e-02 2.0e-01 2.4e-04 5.1e-05 1.5e-04 7.3e-04 Scrap yard

Sr-85 2.0e-01 6.9e-02 1.7e-01 4.5e-01 7.5e-04 2.6e-04 6.1e-04 1.7e-03 Handling slag

Sr-89 1.2e-03 3.8e-04 9.4e-04 2.6e-03 4.3e-06 1.4e-06 3.5e-06 9.7e-06 Handling slag

Sr-90 1.3e-02 4.2e-03 1.1e-02 3.1e-02 5.0e-05 1.6e-05 4.0e-05 1.2e-04 Handling slag

Y-91 3.5e-03 1.2e-03 2.8e-03 7.6e-03 1.3e-05 4.5e-06 1.1e-05 2.8e-05 Handling slag

Zr-93 1.7e-03 5.4e-04 1.4e-03 4.1e-03 6.5e-06 2.0e-06 5.2e-06 1.5e-05 Handling slag

Zr-95 4.4e-01 1.6e-01 3.7e-01 9.7e-01 1.6e-03 5.8e-04 1.4e-03 3.6e-03 Handling slag

Nb-93m 6.1e-04 1.9e-04 4.9e-04 1.4e-03 2.3e-06 7.0e-07 1.8e-06 5.3e-06 Handling slag

Nb-94 8.7e-01 3.1e-01 7.2e-01 1.9e+00 3.2e-03 1.1e-03 2.7e-03 7.0e-03 Handling slag

Nb-95 2.8e-01 8.7e-02 2.2e-01 6.3e-01 1.0e-03 3.2e-04 8.2e-04 2.3e-03 Handling slag

Mo-93 6.4e-04 2.0e-04 5.1e-04 1.5e-03 2.4e-06 7.5e-07 1.9e-06 5.5e-06 Handling slag

Tc-97 1.1e-03 0.0e+00 0.0e+00 4.5e-03 4.1e-06 0.0e+00 0.0e+00 1.7e-05 Leachate-industrial-scrap

Tc-97m 1.6e-04 5.4e-05 1.3e-04 3.6e-04 6.0e-07 2.0e-07 4.8e-07 1.3e-06 Handling slag

Tc-99 9.5e-03 0.0e+00 0.0e+00 3.8e-02 3.5e-05 0.0e+00 0.0e+00 1.4e-04 Leachate-industrial-scrap

Ru-103 1.1e-01 2.3e-02 7.2e-02 3.5e-01 4.2e-04 8.6e-05 2.7e-04 1.3e-03 Scrap yard

Ru-106 8.0e-02 1.7e-02 5.0e-02 2.4e-01 2.9e-04 6.4e-05 1.9e-04 8.9e-04 Scrap yard

a

 5th percentile to 95th percentile = 90% confidence interval
Chapter 4 Recycling and Disposal of Copper Scrap

Table 4.9 Normalized mass-based effective dose equivalents to critical groups for copper

Radionuclide

:Sv/y per Bq/g mrem/y per pCi/g

Scenario

Mean

Percentilea

Mean

Percentilea

5th 50th 95th 5th 50th 95th

4-31 NUREG-1640

Ag-108m 5.5e-01 1.2e-01 3.5e-01 1.7e+00 2.0e-03 4.4e-04 1.3e-03 6.2e-03 Scrap yard

Ag-110m 9.7e-01 2.1e-01 6.2e-01 2.9e+00 3.6e-03 7.6e-04 2.3e-03 1.1e-02 Scrap yard

Cd-109 1.5e-03 5.0e-04 1.2e-03 3.4e-03 5.6e-06 1.9e-06 4.6e-06 1.3e-05 Handling slag

Sn-113 9.1e-02 3.1e-02 7.5e-02 2.0e-01 3.4e-04 1.2e-04 2.8e-04 7.4e-04 Handling slag

Sb-124 5.8e-01 1.9e-01 4.7e-01 1.3e+00 2.2e-03 6.9e-04 1.7e-03 4.9e-03 Handling slag

Sb-125 1.6e-01 5.2e-02 1.3e-01 3.6e-01 5.9e-04 1.9e-04 4.7e-04 1.3e-03 Handling slag

Te-123m 1.3e-02 2.8e-03 8.5e-03 4.1e-02 5.0e-05 1.1e-05 3.1e-05 1.5e-04 Scrap yard

Te-127m 1.5e-03 3.4e-04 9.3e-04 4.5e-03 5.5e-06 1.2e-06 3.5e-06 1.7e-05 Scrap yard

I-125 1.5e-03 3.7e-04 1.2e-03 3.9e-03 5.7e-06 1.4e-06 4.4e-06 1.4e-05 Handling slag

I-129 4.0e-01 0.0e+00 0.0e+00 1.4e+00 1.5e-03 0.0e+00 0.0e+00 5.3e-03 Leachate-industrial-scrap

I-131 3.6e-02 3.6e-03 2.1e-02 1.2e-01 1.3e-04 1.3e-05 7.9e-05 4.5e-04 Handling slag

Cs-134 5.5e-01 1.2e-01 3.5e-01 1.7e+00 2.0e-03 4.4e-04 1.3e-03 6.2e-03 Scrap yard

Cs-135 8.6e-05 1.4e-05 5.5e-05 2.7e-04 3.2e-07 5.1e-08 2.0e-07 1.0e-06 Scrap yard

Cs-137 2.0e-01 4.3e-02 1.3e-01 6.0e-01 7.4e-04 1.6e-04 4.6e-04 2.2e-03 Scrap yard

Ba-133 1.5e-01 5.4e-02 1.3e-01 3.3e-01 5.7e-04 2.0e-04 4.7e-04 1.2e-03 Handling slag

Ce-139 2.9e-02 1.0e-02 2.4e-02 6.4e-02 1.1e-04 3.8e-05 8.9e-05 2.4e-04 Handling slag

Ce-141 9.1e-03 2.8e-03 7.3e-03 2.1e-02 3.4e-05 1.0e-05 2.7e-05 7.8e-05 Handling slag

Ce-144 3.0e-02 1.1e-02 2.5e-02 6.5e-02 1.1e-04 4.1e-05 9.4e-05 2.4e-04 Handling slag

Pm-147 8.2e-04 2.5e-04 6.6e-04 1.9e-03 3.0e-06 9.4e-07 2.4e-06 7.1e-06 Handling slag

Sm-151 6.2e-04 1.9e-04 5.0e-04 1.5e-03 2.3e-06 7.1e-07 1.8e-06 5.4e-06 Handling slag

Eu-152 6.1e-01 2.1e-01 5.1e-01 1.3e+00 2.3e-03 7.9e-04 1.9e-03 4.9e-03 Handling slag

Eu-154 6.0e-01 2.1e-01 5.0e-01 1.3e+00 2.2e-03 7.8e-04 1.8e-03 4.8e-03 Handling slag

Eu-155 6.2e-03 2.3e-03 5.2e-03 1.3e-02 2.3e-05 8.4e-06 1.9e-05 5.0e-05 Handling slag

Gd-153 6.7e-03 2.4e-03 5.6e-03 1.5e-02 2.5e-05 8.8e-06 2.1e-05 5.4e-05 Handling slag

Tb-160 4.9e-01 1.7e-01 4.0e-01 1.1e+00 1.8e-03 6.2e-04 1.5e-03 4.0e-03 Handling slag

Tm-170 1.1e-03 3.8e-04 8.8e-04 2.3e-03 3.9e-06 1.4e-06 3.2e-06 8.6e-06 Handling slag

Tm-171 2.2e-04 7.1e-05 1.8e-04 5.0e-04 8.1e-07 2.6e-07 6.5e-07 1.8e-06 Handling slag

Ta-182 5.9e-01 2.0e-01 4.8e-01 1.3e+00 2.2e-03 7.6e-04 1.8e-03 4.8e-03 Handling slag

W-181 1.5e-03 5.1e-04 1.2e-03 3.2e-03 5.5e-06 1.9e-06 4.5e-06 1.2e-05 Handling slag

W-185 7.6e-05 1.9e-05 5.9e-05 1.9e-04 2.8e-07 7.2e-08 2.2e-07 7.0e-07 Handling slag

Os-185 2.0e-01 4.2e-02 1.3e-01 6.1e-01 7.4e-04 1.5e-04 4.7e-04 2.3e-03 Scrap yard

Ir-192 1.9e-01 4.0e-02 1.2e-01 5.8e-01 7.0e-04 1.5e-04 4.4e-04 2.2e-03 Scrap yard

Tl-204 1.9e-04 4.7e-05 1.2e-04 5.6e-04 7.0e-07 1.8e-07 4.5e-07 2.1e-06 Scrap yard

Pb-210 3.9e-01 6.8e-02 2.9e-01 1.0e+00 1.4e-03 2.5e-04 1.1e-03 3.8e-03 Handling slag

Bi-207 5.5e-01 1.2e-01 3.5e-01 1.7e+00 2.0e-03 4.4e-04 1.3e-03 6.2e-03 Scrap yard

Po-210 3.9e-02 1.0e-02 2.5e-02 1.2e-01 1.5e-04 3.7e-05 9.2e-05 4.5e-04 Scrap yard

Ra-226 1.1e+00 4.2e-01 9.6e-01 2.5e+00 4.3e-03 1.5e-03 3.6e-03 9.2e-03 Handling slag

Ra-228 7.8e-01 2.8e-01 6.4e-01 1.7e+00 2.9e-03 1.0e-03 2.4e-03 6.3e-03 Handling slag

a

 5th percentile to 95th percentile = 90% confidence interval
Recycling and Disposal of Copper Scrap Chapter 4

Table 4.9 Normalized mass-based effective dose equivalents to critical groups for copper

Radionuclide

:Sv/y per Bq/g mrem/y per pCi/g

Scenario

Mean

Percentilea

Mean

Percentilea

5th 50th 95th 5th 50th 95th

NUREG-1640 4-32

Ac-227 2.7e+01 8.4e+00 2.2e+01 6.4e+01 1.0e-01 3.1e-02 8.1e-02 2.4e-01 Handling slag

Th-228 7.6e+00 2.4e+00 6.1e+00 1.8e+01 2.8e-02 8.9e-03 2.3e-02 6.5e-02 Handling slag

Th-229 3.6e+01 1.1e+01 2.8e+01 8.4e+01 1.3e-01 4.0e-02 1.0e-01 3.1e-01 Handling slag

Th-230 5.3e+00 1.6e+00 4.2e+00 1.3e+01 2.0e-02 6.0e-03 1.6e-02 4.6e-02 Handling slag

Th-232 2.4e+01 7.2e+00 1.9e+01 5.6e+01 8.7e-02 2.7e-02 6.9e-02 2.1e-01 Handling slag

Pa-231 1.8e+01 5.5e+00 1.4e+01 4.2e+01 6.6e-02 2.0e-02 5.3e-02 1.5e-01 Handling slag

U-232 1.3e+01 4.1e+00 1.1e+01 3.2e+01 5.0e-02 1.5e-02 4.0e-02 1.2e-01 Handling slag

U-233 2.7e+00 8.3e-01 2.2e+00 6.5e+00 1.0e-02 3.1e-03 8.1e-03 2.4e-02 Handling slag

U-234 2.7e+00 8.1e-01 2.1e+00 6.3e+00 9.9e-03 3.0e-03 7.9e-03 2.3e-02 Handling slag

U-235 2.6e+00 7.9e-01 2.1e+00 6.1e+00 9.6e-03 2.9e-03 7.6e-03 2.2e-02 Handling slag

U-236 2.5e+00 7.7e-01 2.0e+00 6.0e+00 9.4e-03 2.8e-03 7.5e-03 2.2e-02 Handling slag

U-238 2.4e+00 7.3e-01 1.9e+00 5.7e+00 8.9e-03 2.7e-03 7.1e-03 2.1e-02 Handling slag

Np-237 1.1e+01 3.4e+00 8.9e+00 2.6e+01 4.1e-02 1.3e-02 3.3e-02 9.7e-02 Handling slag

Pu-236 2.8e+00 8.6e-01 2.2e+00 6.6e+00 1.0e-02 3.2e-03 8.3e-03 2.4e-02 Handling slag

Pu-238 6.0e+00 1.8e+00 4.7e+00 1.4e+01 2.2e-02 6.7e-03 1.8e-02 5.2e-02 Handling slag

Pu-239 6.4e+00 2.0e+00 5.1e+00 1.5e+01 2.4e-02 7.2e-03 1.9e-02 5.5e-02 Handling slag

Pu-240 6.4e+00 2.0e+00 5.1e+00 1.5e+01 2.4e-02 7.2e-03 1.9e-02 5.5e-02 Handling slag

Pu-241 1.0e-01 3.2e-02 8.3e-02 2.4e-01 3.8e-04 1.2e-04 3.1e-04 9.0e-04 Handling slag

Pu-242 6.1e+00 1.9e+00 4.8e+00 1.4e+01 2.2e-02 6.9e-03 1.8e-02 5.3e-02 Handling slag

Pu-244 6.2e+00 1.9e+00 4.9e+00 1.4e+01 2.3e-02 7.1e-03 1.8e-02 5.3e-02 Handling slag

Am-241 9.1e+00 2.8e+00 7.3e+00 2.2e+01 3.4e-02 1.0e-02 2.7e-02 8.0e-02 Handling slag

Am-242m 9.0e+00 2.8e+00 7.2e+00 2.1e+01 3.3e-02 1.0e-02 2.7e-02 7.9e-02 Handling slag

Am-243 9.1e+00 2.8e+00 7.3e+00 2.1e+01 3.4e-02 1.0e-02 2.7e-02 7.9e-02 Handling slag

Cm-242 3.2e-01 9.9e-02 2.6e-01 7.7e-01 1.2e-03 3.7e-04 9.6e-04 2.8e-03 Handling slag

Cm-243 6.3e+00 1.9e+00 5.1e+00 1.5e+01 2.3e-02 7.2e-03 1.9e-02 5.5e-02 Handling slag

Cm-244 5.1e+00 1.6e+00 4.1e+00 1.2e+01 1.9e-02 5.8e-03 1.5e-02 4.4e-02 Handling slag

Cm-245 9.4e+00 2.9e+00 7.5e+00 2.2e+01 3.5e-02 1.1e-02 2.8e-02 8.2e-02 Handling slag

Cm-246 9.3e+00 2.8e+00 7.4e+00 2.2e+01 3.4e-02 1.0e-02 2.7e-02 8.1e-02 Handling slag

Cm-247 8.7e+00 2.7e+00 6.9e+00 2.0e+01 3.2e-02 9.9e-03 2.6e-02 7.5e-02 Handling slag

Cm-248 3.4e+01 1.0e+01 2.7e+01 8.0e+01 1.3e-01 3.8e-02 1.0e-01 3.0e-01 Handling slag

Bk-249 2.8e-02 8.6e-03 2.2e-02 6.6e-02 1.0e-04 3.2e-05 8.3e-05 2.5e-04 Handling slag

Cf-248 1.0e+00 3.1e-01 8.0e-01 2.4e+00 3.7e-03 1.1e-03 3.0e-03 8.8e-03 Handling slag

Cf-249 8.0e+00 2.5e+00 6.4e+00 1.9e+01 3.0e-02 9.2e-03 2.4e-02 7.0e-02 Handling slag

Cf-250 4.2e+00 1.3e+00 3.4e+00 1.0e+01 1.6e-02 4.8e-03 1.3e-02 3.7e-02 Handling slag

Cf-251 8.1e+00 2.5e+00 6.4e+00 1.9e+01 3.0e-02 9.2e-03 2.4e-02 7.0e-02 Handling slag

Cf-252 3.2e+00 9.7e-01 2.5e+00 7.5e+00 1.2e-02 3.6e-03 9.3e-03 2.8e-02 Handling slag

Cf-254 1.2e+01 4.3e+00 1.0e+01 2.7e+01 4.5e-02 1.6e-02 3.7e-02 9.9e-02 Handling slag

Es-254 1.3e+00 4.5e-01 1.1e+00 2.8e+00 4.7e-03 1.7e-03 3.9e-03 1.1e-02 Handling slag

a

 5th percentile to 95th percentile = 90% confidence interval
Chapter 4 Recycling and Disposal of Copper Scrap

4-33 NUREG-1640

Table 4.10 Normalized surficial effective dose equivalents to critical groups for copper

Radionuclide

:Sv/y per Bq/cm2 mrem/y per pCi/cm2

Mean

Percentilea

Mean

Percentilea

Scenario

5th 50th 95th 5th 50th 95th

H-3 2.0e-04 0.0e+00 1.5e-07 8.2e-04 7.3e-07 0.0e+00 5.4e-10 3.0e-06 Leachate-industrial-scrap

C-14 4.7e-04 1.4e-04 3.5e-04 1.2e-03 1.7e-06 5.3e-07 1.3e-06 4.4e-06 Airborne emissions

Na-22 2.3e+00 7.7e-01 1.9e+00 5.0e+00 8.3e-03 2.9e-03 6.9e-03 1.8e-02 Handling slag

P-32 1.5e-03 2.4e-04 9.0e-04 4.9e-03 5.7e-06 8.9e-07 3.3e-06 1.8e-05 Scrap yard

S-35 5.3e-05 1.1e-05 3.9e-05 1.4e-04 2.0e-07 4.1e-08 1.4e-07 5.2e-07 Handling slag

Cl-36 4.0e-03 0.0e+00 0.0e+00 1.6e-02 1.5e-05 0.0e+00 0.0e+00 5.8e-05 Leachate-industrial-scrap

K-40 1.3e-01 2.7e-02 7.9e-02 3.7e-01 4.7e-04 9.9e-05 2.9e-04 1.4e-03 Scrap yard

Ca-41 2.2e-03 0.0e+00 0.0e+00 9.2e-03 8.2e-06 0.0e+00 0.0e+00 3.4e-05 Leachate-industrial-scrap

Ca-45 4.3e-04 1.2e-04 3.4e-04 1.0e-03 1.6e-06 4.5e-07 1.3e-06 3.8e-06 Handling slag

Sc-46 1.8e+00 6.1e-01 1.5e+00 4.0e+00 6.7e-03 2.3e-03 5.5e-03 1.5e-02 Handling slag

Cr-51 1.6e-02 4.7e-03 1.3e-02 3.8e-02 5.9e-05 1.7e-05 4.7e-05 1.4e-04 Handling slag

Mn-53 2.6e-05 8.1e-06 2.1e-05 6.1e-05 9.7e-08 3.0e-08 7.7e-08 2.3e-07 Handling slag

Mn-54 8.4e-01 2.9e-01 6.9e-01 1.9e+00 3.1e-03 1.1e-03 2.6e-03 6.9e-03 Handling slag

Fe-55 8.4e-05 2.4e-05 6.6e-05 2.0e-04 3.1e-07 8.8e-08 2.4e-07 7.4e-07 Handling slag

Fe-59 8.4e-01 2.7e-01 6.8e-01 1.9e+00 3.1e-03 1.0e-03 2.5e-03 7.1e-03 Handling slag

Co-56 2.5e+00 8.0e-01 2.0e+00 5.6e+00 9.3e-03 3.0e-03 7.5e-03 2.1e-02 Handling slag

Co-57 2.9e-02 9.5e-03 2.4e-02 6.5e-02 1.1e-04 3.5e-05 8.8e-05 2.4e-04 Handling slag

Co-58 6.8e-01 2.2e-01 5.5e-01 1.5e+00 2.5e-03 8.1e-04 2.0e-03 5.7e-03 Handling slag

Co-60 2.2e+00 7.2e-01 1.8e+00 4.9e+00 8.1e-03 2.7e-03 6.6e-03 1.8e-02 Handling slag

Ni-59 5.4e-05 1.7e-05 4.3e-05 1.2e-04 2.0e-07 6.4e-08 1.6e-07 4.5e-07 Handling slag

Ni-63 1.0e-04 3.1e-05 8.2e-05 2.5e-04 3.9e-07 1.1e-07 3.0e-07 9.1e-07 Handling slag

Zn-65 5.3e-01 1.8e-01 4.4e-01 1.2e+00 2.0e-03 6.7e-04 1.6e-03 4.3e-03 Handling slag

As-73 3.2e-04 1.2e-05 9.9e-05 1.1e-03 1.2e-06 4.5e-08 3.7e-07 4.2e-06 Scrap disposal-industrial

Se-75 1.3e-01 2.6e-02 8.0e-02 3.8e-01 4.7e-04 9.8e-05 2.9e-04 1.4e-03 Scrap yard

Sr-85 3.9e-01 1.3e-01 3.2e-01 8.8e-01 1.4e-03 4.8e-04 1.2e-03 3.2e-03 Handling slag

Sr-89 2.2e-03 7.3e-04 1.8e-03 5.2e-03 8.3e-06 2.7e-06 6.7e-06 1.9e-05 Handling slag

Sr-90 2.6e-02 8.0e-03 2.1e-02 6.0e-02 9.7e-05 3.0e-05 7.7e-05 2.2e-04 Handling slag

Y-91 6.7e-03 2.3e-03 5.5e-03 1.5e-02 2.5e-05 8.5e-06 2.0e-05 5.6e-05 Handling slag

Zr-93 3.4e-03 1.0e-03 2.7e-03 8.0e-03 1.3e-05 3.8e-06 1.0e-05 3.0e-05 Handling slag

Zr-95 8.6e-01 3.0e-01 7.1e-01 1.9e+00 3.2e-03 1.1e-03 2.6e-03 7.0e-03 Handling slag

Nb-93m 1.2e-03 3.6e-04 9.4e-04 2.8e-03 4.4e-06 1.3e-06 3.5e-06 1.0e-05 Handling slag

Nb-94 1.7e+00 5.8e-01 1.4e+00 3.7e+00 6.2e-03 2.1e-03 5.2e-03 1.4e-02 Handling slag

Nb-95 5.3e-01 1.7e-01 4.3e-01 1.2e+00 2.0e-03 6.2e-04 1.6e-03 4.6e-03 Handling slag

Mo-93 1.2e-03 3.9e-04 9.9e-04 2.9e-03 4.6e-06 1.4e-06 3.7e-06 1.1e-05 Handling slag

Tc-97 2.1e-03 0.0e+00 0.0e+00 8.7e-03 8.0e-06 0.0e+00 0.0e+00 3.2e-05 Leachate-industrial-scrap

Tc-97m 3.1e-04 1.0e-04 2.5e-04 7.1e-04 1.2e-06 3.8e-07 9.4e-07 2.6e-06 Handling slag

Tc-99 1.8e-02 0.0e+00 0.0e+00 7.5e-02 6.8e-05 0.0e+00 0.0e+00 2.8e-04 Leachate-industrial-scrap

Ru-103 2.2e-01 4.4e-02 1.4e-01 6.8e-01 8.2e-04 1.6e-04 5.1e-04 2.5e-03 Scrap yard

Ru-106 1.5e-01 3.3e-02 9.8e-02 4.5e-01 5.7e-04 1.2e-04 3.6e-04 1.7e-03 Scrap yard

a

 5th percentile to 95th percentile = 90% confidence interval
Recycling and Disposal of Copper Scrap Chapter 4

Table 4.10 Normalized surficial effective dose equivalents to critical groups for copper

Radionuclide

:Sv/y per Bq/cm2 mrem/y per pCi/cm2

Mean

Percentilea

Mean

Percentilea

Scenario

5th 50th 95th 5th 50th 95th

NUREG-1640 4-34

Ag-108m 1.1e+00 2.3e-01 6.7e-01 3.2e+00 3.9e-03 8.3e-04 2.5e-03 1.2e-02 Scrap yard

Ag-110m 1.9e+00 4.0e-01 1.2e+00 5.6e+00 7.0e-03 1.5e-03 4.4e-03 2.1e-02 Scrap yard

Cd-109 2.9e-03 9.6e-04 2.4e-03 6.7e-03 1.1e-05 3.5e-06 8.7e-06 2.5e-05 Handling slag

Sn-113 1.8e-01 6.0e-02 1.4e-01 3.9e-01 6.5e-04 2.2e-04 5.4e-04 1.4e-03 Handling slag

Sb-124 1.1e+00 3.5e-01 9.0e-01 2.6e+00 4.2e-03 1.3e-03 3.3e-03 9.7e-03 Handling slag

Sb-125 3.1e-01 9.9e-02 2.5e-01 7.0e-01 1.1e-03 3.7e-04 9.1e-04 2.6e-03 Handling slag

Te-123m 2.6e-02 5.5e-03 1.6e-02 7.7e-02 9.6e-05 2.0e-05 6.1e-05 2.9e-04 Scrap yard

Te-127m 2.9e-03 6.5e-04 1.8e-03 8.6e-03 1.1e-05 2.4e-06 6.7e-06 3.2e-05 Scrap yard

I-125 3.0e-03 7.1e-04 2.3e-03 7.6e-03 1.1e-05 2.6e-06 8.4e-06 2.8e-05 Handling slag

I-129 7.8e-01 0.0e+00 0.0e+00 2.7e+00 2.9e-03 0.0e+00 0.0e+00 1.0e-02 Leachate-industrial-scrap

I-131 7.1e-02 6.9e-03 4.1e-02 2.3e-01 2.6e-04 2.5e-05 1.5e-04 8.7e-04 Handling slag

Cs-134 1.1e+00 2.2e-01 6.7e-01 3.1e+00 3.9e-03 8.3e-04 2.5e-03 1.2e-02 Scrap yard

Cs-135 1.7e-04 2.6e-05 1.1e-04 5.2e-04 6.2e-07 9.8e-08 3.9e-07 1.9e-06 Scrap yard

Cs-137 3.9e-01 8.1e-02 2.4e-01 1.1e+00 1.4e-03 3.0e-04 9.0e-04 4.2e-03 Scrap yard

Ba-133 3.0e-01 1.0e-01 2.5e-01 6.5e-01 1.1e-03 3.8e-04 9.1e-04 2.4e-03 Handling slag

Ce-139 5.6e-02 1.9e-02 4.6e-02 1.2e-01 2.1e-04 7.1e-05 1.7e-04 4.6e-04 Handling slag

Ce-141 1.8e-02 5.5e-03 1.4e-02 4.1e-02 6.5e-05 2.0e-05 5.2e-05 1.5e-04 Handling slag

Ce-144 5.9e-02 2.1e-02 4.9e-02 1.3e-01 2.2e-04 7.8e-05 1.8e-04 4.7e-04 Handling slag

Pm-147 1.6e-03 4.9e-04 1.3e-03 3.7e-03 5.9e-06 1.8e-06 4.7e-06 1.4e-05 Handling slag

Sm-151 1.2e-03 3.7e-04 9.6e-04 2.8e-03 4.5e-06 1.4e-06 3.5e-06 1.1e-05 Handling slag

Eu-152 1.2e+00 4.0e-01 9.7e-01 2.6e+00 4.4e-03 1.5e-03 3.6e-03 9.6e-03 Handling slag

Eu-154 1.2e+00 4.0e-01 9.5e-01 2.5e+00 4.3e-03 1.5e-03 3.5e-03 9.4e-03 Handling slag

Eu-155 1.2e-02 4.3e-03 1.0e-02 2.6e-02 4.5e-05 1.6e-05 3.7e-05 9.7e-05 Handling slag

Gd-153 1.3e-02 4.5e-03 1.1e-02 2.9e-02 4.8e-05 1.7e-05 4.0e-05 1.1e-04 Handling slag

Tb-160 9.4e-01 3.2e-01 7.7e-01 2.1e+00 3.5e-03 1.2e-03 2.9e-03 7.8e-03 Handling slag

Tm-170 2.1e-03 7.1e-04 1.7e-03 4.6e-03 7.6e-06 2.6e-06 6.3e-06 1.7e-05 Handling slag

Tm-171 4.2e-04 1.4e-04 3.4e-04 9.8e-04 1.6e-06 5.1e-07 1.3e-06 3.6e-06 Handling slag

Ta-182 1.1e+00 3.9e-01 9.4e-01 2.5e+00 4.2e-03 1.4e-03 3.5e-03 9.3e-03 Handling slag

W-181 2.9e-03 9.7e-04 2.4e-03 6.3e-03 1.1e-05 3.6e-06 8.7e-06 2.3e-05 Handling slag

W-185 1.5e-04 3.7e-05 1.1e-04 3.7e-04 5.5e-07 1.4e-07 4.2e-07 1.4e-06 Handling slag

Os-185 3.9e-01 8.1e-02 2.4e-01 1.2e+00 1.4e-03 3.0e-04 9.0e-04 4.3e-03 Scrap yard

Ir-192 3.7e-01 7.6e-02 2.3e-01 1.1e+00 1.4e-03 2.8e-04 8.6e-04 4.1e-03 Scrap yard

Tl-204 3.7e-04 9.1e-05 2.3e-04 1.1e-03 1.4e-06 3.3e-07 8.7e-07 4.1e-06 Scrap yard

Pb-210 7.5e-01 1.3e-01 5.6e-01 2.0e+00 2.8e-03 4.7e-04 2.1e-03 7.3e-03 Handling slag

Bi-207 1.1e+00 2.3e-01 6.7e-01 3.2e+00 4.0e-03 8.3e-04 2.5e-03 1.2e-02 Scrap yard

Po-210 7.7e-02 1.9e-02 4.8e-02 2.3e-01 2.8e-04 7.1e-05 1.8e-04 8.7e-04 Scrap yard

Ra-226 2.2e+00 7.9e-01 1.8e+00 4.8e+00 8.2e-03 2.9e-03 6.8e-03 1.8e-02 Handling slag

Ra-228 1.5e+00 5.2e-01 1.2e+00 3.3e+00 5.6e-03 1.9e-03 4.6e-03 1.2e-02 Handling slag

a

 5th percentile to 95th percentile = 90% confidence interval
Chapter 4 Recycling and Disposal of Copper Scrap

Table 4.10 Normalized surficial effective dose equivalents to critical groups for copper

Radionuclide

:Sv/y per Bq/cm2 mrem/y per pCi/cm2

Mean

Percentilea

Mean

Percentilea

Scenario

5th 50th 95th 5th 50th 95th

4-35 NUREG-1640

Ac-227 5.3e+01 1.6e+01 4.2e+01 1.2e+02 2.0e-01 5.9e-02 1.6e-01 4.6e-01 Handling slag

Th-228 1.5e+01 4.6e+00 1.2e+01 3.4e+01 5.4e-02 1.7e-02 4.3e-02 1.3e-01 Handling slag

Th-229 6.9e+01 2.1e+01 5.5e+01 1.6e+02 2.5e-01 7.7e-02 2.0e-01 6.0e-01 Handling slag

Th-230 1.0e+01 3.1e+00 8.2e+00 2.4e+01 3.8e-02 1.1e-02 3.0e-02 9.0e-02 Handling slag

Th-232 4.6e+01 1.4e+01 3.6e+01 1.1e+02 1.7e-01 5.1e-02 1.3e-01 4.0e-01 Handling slag

Pa-231 3.4e+01 1.0e+01 2.7e+01 8.2e+01 1.3e-01 3.9e-02 1.0e-01 3.0e-01 Handling slag

U-232 2.6e+01 7.9e+00 2.1e+01 6.2e+01 9.7e-02 2.9e-02 7.7e-02 2.3e-01 Handling slag

U-233 5.3e+00 1.6e+00 4.2e+00 1.3e+01 2.0e-02 5.9e-03 1.6e-02 4.7e-02 Handling slag

U-234 5.2e+00 1.6e+00 4.1e+00 1.2e+01 1.9e-02 5.8e-03 1.5e-02 4.6e-02 Handling slag

U-235 5.0e+00 1.5e+00 4.0e+00 1.2e+01 1.9e-02 5.6e-03 1.5e-02 4.4e-02 Handling slag

U-236 4.9e+00 1.5e+00 3.9e+00 1.2e+01 1.8e-02 5.5e-03 1.4e-02 4.3e-02 Handling slag

U-238 4.7e+00 1.4e+00 3.7e+00 1.1e+01 1.7e-02 5.2e-03 1.4e-02 4.1e-02 Handling slag

Np-237 2.2e+01 6.6e+00 1.7e+01 5.1e+01 8.0e-02 2.4e-02 6.4e-02 1.9e-01 Handling slag

Pu-236 5.4e+00 1.6e+00 4.3e+00 1.3e+01 2.0e-02 6.1e-03 1.6e-02 4.8e-02 Handling slag

Pu-238 1.2e+01 3.5e+00 9.2e+00 2.7e+01 4.3e-02 1.3e-02 3.4e-02 1.0e-01 Handling slag

Pu-239 1.2e+01 3.7e+00 9.8e+00 2.9e+01 4.6e-02 1.4e-02 3.6e-02 1.1e-01 Handling slag

Pu-240 1.2e+01 3.7e+00 9.8e+00 2.9e+01 4.6e-02 1.4e-02 3.6e-02 1.1e-01 Handling slag

Pu-241 2.0e-01 6.1e-02 1.6e-01 4.7e-01 7.4e-04 2.3e-04 5.9e-04 1.8e-03 Handling slag

Pu-242 1.2e+01 3.6e+00 9.3e+00 2.8e+01 4.3e-02 1.3e-02 3.4e-02 1.0e-01 Handling slag

Pu-244 1.2e+01 3.7e+00 9.5e+00 2.8e+01 4.4e-02 1.4e-02 3.5e-02 1.0e-01 Handling slag

Am-241 1.8e+01 5.4e+00 1.4e+01 4.2e+01 6.5e-02 2.0e-02 5.2e-02 1.5e-01 Handling slag

Am-242m 1.8e+01 5.3e+00 1.4e+01 4.2e+01 6.5e-02 2.0e-02 5.1e-02 1.5e-01 Handling slag

Am-243 1.8e+01 5.3e+00 1.4e+01 4.2e+01 6.5e-02 2.0e-02 5.2e-02 1.5e-01 Handling slag

Cm-242 6.3e-01 1.9e-01 5.0e-01 1.5e+00 2.3e-03 7.0e-04 1.9e-03 5.5e-03 Handling slag

Cm-243 1.2e+01 3.7e+00 9.7e+00 2.9e+01 4.5e-02 1.4e-02 3.6e-02 1.1e-01 Handling slag

Cm-244 9.8e+00 3.0e+00 7.8e+00 2.3e+01 3.6e-02 1.1e-02 2.9e-02 8.6e-02 Handling slag

Cm-245 1.8e+01 5.5e+00 1.4e+01 4.3e+01 6.7e-02 2.0e-02 5.3e-02 1.6e-01 Handling slag

Cm-246 1.8e+01 5.5e+00 1.4e+01 4.3e+01 6.6e-02 2.0e-02 5.3e-02 1.6e-01 Handling slag

Cm-247 1.7e+01 5.1e+00 1.3e+01 4.0e+01 6.2e-02 1.9e-02 4.9e-02 1.5e-01 Handling slag

Cm-248 6.6e+01 2.0e+01 5.2e+01 1.6e+02 2.4e-01 7.4e-02 1.9e-01 5.8e-01 Handling slag

Bk-249 5.4e-02 1.6e-02 4.3e-02 1.3e-01 2.0e-04 6.1e-05 1.6e-04 4.8e-04 Handling slag

Cf-248 1.9e+00 5.9e-01 1.5e+00 4.6e+00 7.2e-03 2.2e-03 5.7e-03 1.7e-02 Handling slag

Cf-249 1.6e+01 4.8e+00 1.2e+01 3.7e+01 5.8e-02 1.8e-02 4.6e-02 1.4e-01 Handling slag

Cf-250 8.2e+00 2.5e+00 6.5e+00 1.9e+01 3.0e-02 9.2e-03 2.4e-02 7.2e-02 Handling slag

Cf-251 1.6e+01 4.7e+00 1.2e+01 3.7e+01 5.8e-02 1.8e-02 4.6e-02 1.4e-01 Handling slag

Cf-252 6.1e+00 1.9e+00 4.9e+00 1.5e+01 2.3e-02 6.8e-03 1.8e-02 5.4e-02 Handling slag

Cf-254 2.4e+01 8.2e+00 1.9e+01 5.3e+01 8.8e-02 3.0e-02 7.2e-02 2.0e-01 Handling slag

Es-254 2.5e+00 8.6e-01 2.0e+00 5.5e+00 9.2e-03 3.2e-03 7.5e-03 2.1e-02 Handling slag

a

 5th percentile to 95th percentile = 90% confidence interval
Recycling and Disposal of Copper Scrap Chapter 4

NUREG-1640 4-36

Table 4.11 Normalized mass-based effective doses to critical groups for copper

Radionuclide

:Sv/y per Bq/g mrem/y per pCi/g

Mean

Percentilea

Mean

Percentilea

Scenario

5th 50th 95th 5th 50th 95th

H-3 1.1e-04 0.0e+00 7.9e-08 4.4e-04 3.9e-07 0.0e+00 2.9e-10 1.6e-06 Leachate-industrial-scrap

C-14 2.5e-04 7.7e-05 1.9e-04 6.3e-04 9.2e-07 2.8e-07 6.9e-07 2.3e-06 Airborne emissions

Na-22 1.1e+00 4.0e-01 9.4e-01 2.5e+00 4.2e-03 1.5e-03 3.5e-03 9.2e-03 Handling slag

P-32 7.8e-04 1.2e-04 4.6e-04 2.5e-03 2.9e-06 4.5e-07 1.7e-06 9.4e-06 Scrap yard

S-35 4.2e-05 8.8e-06 3.1e-05 1.1e-04 1.5e-07 3.3e-08 1.2e-07 4.1e-07 Handling slag

Cl-36 2.3e-03 0.0e+00 0.0e+00 9.2e-03 8.7e-06 0.0e+00 0.0e+00 3.4e-05 Leachate-industrial-scrap

K-40 6.5e-02 1.4e-02 4.1e-02 2.0e-01 2.4e-04 5.2e-05 1.5e-04 7.3e-04 Scrap yard

Ca-41 9.5e-04 0.0e+00 0.0e+00 4.0e-03 3.5e-06 0.0e+00 0.0e+00 1.5e-05 Leachate-industrial-scrap

Ca-45 2.5e-04 7.5e-05 2.0e-04 5.7e-04 9.1e-07 2.8e-07 7.3e-07 2.1e-06 Handling slag

Sc-46 9.1e-01 3.1e-01 7.5e-01 2.0e+00 3.4e-03 1.2e-03 2.8e-03 7.4e-03 Handling slag

Cr-51 7.9e-03 2.4e-03 6.3e-03 1.9e-02 2.9e-05 8.7e-06 2.3e-05 7.0e-05 Handling slag

Mn-53 6.3e-06 1.6e-06 4.9e-06 1.5e-05 2.3e-08 5.9e-09 1.8e-08 5.7e-08 Handling slag

Mn-54 4.2e-01 1.5e-01 3.5e-01 9.2e-01 1.6e-03 5.5e-04 1.3e-03 3.4e-03 Handling slag

Fe-55 6.0e-05 1.4e-05 4.6e-05 1.5e-04 2.2e-07 5.3e-08 1.7e-07 5.5e-07 Handling slag

Fe-59 4.3e-01 1.4e-01 3.4e-01 9.6e-01 1.6e-03 5.2e-04 1.3e-03 3.6e-03 Handling slag

Co-56 1.3e+00 4.2e-01 1.0e+00 2.8e+00 4.7e-03 1.5e-03 3.8e-03 1.0e-02 Handling slag

Co-57 1.5e-02 4.8e-03 1.2e-02 3.2e-02 5.4e-05 1.8e-05 4.4e-05 1.2e-04 Handling slag

Co-58 3.4e-01 1.1e-01 2.8e-01 7.7e-01 1.3e-03 4.1e-04 1.0e-03 2.8e-03 Handling slag

Co-60 1.1e+00 3.7e-01 9.0e-01 2.4e+00 4.1e-03 1.4e-03 3.3e-03 9.1e-03 Handling slag

Ni-59 1.9e-05 5.9e-06 1.5e-05 4.3e-05 6.9e-08 2.2e-08 5.5e-08 1.6e-07 Handling slag

Ni-63 3.4e-05 9.4e-06 2.7e-05 8.2e-05 1.3e-07 3.5e-08 9.9e-08 3.0e-07 Handling slag

Zn-65 2.7e-01 9.3e-02 2.2e-01 5.8e-01 9.9e-04 3.4e-04 8.2e-04 2.2e-03 Handling slag

As-73 1.4e-04 5.4e-06 4.3e-05 4.7e-04 5.2e-07 2.0e-08 1.6e-07 1.7e-06 Scrap disposal-industrial

Se-75 6.5e-02 1.4e-02 4.1e-02 2.0e-01 2.4e-04 5.0e-05 1.5e-04 7.3e-04 Scrap yard

Sr-85 2.0e-01 6.7e-02 1.6e-01 4.4e-01 7.3e-04 2.5e-04 6.0e-04 1.6e-03 Handling slag

Sr-89 1.1e-03 3.7e-04 9.1e-04 2.6e-03 4.1e-06 1.4e-06 3.4e-06 9.4e-06 Handling slag

Sr-90 9.4e-03 2.9e-03 7.4e-03 2.2e-02 3.5e-05 1.1e-05 2.8e-05 8.0e-05 Handling slag

Y-91 3.0e-03 1.0e-03 2.4e-03 6.6e-03 1.1e-05 3.8e-06 9.0e-06 2.4e-05 Handling slag

Zr-93 5.3e-04 1.7e-04 4.3e-04 1.2e-03 2.0e-06 6.1e-07 1.6e-06 4.6e-06 Handling slag

Zr-95 4.3e-01 1.5e-01 3.6e-01 9.5e-01 1.6e-03 5.7e-04 1.3e-03 3.5e-03 Handling slag

Nb-93m 8.1e-05 2.6e-05 6.5e-05 1.9e-04 3.0e-07 9.6e-08 2.4e-07 6.9e-07 Handling slag

Nb-94 8.4e-01 3.0e-01 7.0e-01 1.8e+00 3.1e-03 1.1e-03 2.6e-03 6.8e-03 Handling slag

Nb-95 2.7e-01 8.5e-02 2.2e-01 6.2e-01 9.9e-04 3.1e-04 8.0e-04 2.3e-03 Handling slag

Mo-93 1.2e-03 0.0e+00 0.0e+00 1.4e-03 4.5e-06 0.0e+00 0.0e+00 5.2e-06 Leachate-industrial-scrap

Tc-97 2.0e-03 0.0e+00 0.0e+00 8.1e-03 7.4e-06 0.0e+00 0.0e+00 3.0e-05 Leachate-industrial-scrap

Tc-97m 2.8e-04 8.9e-05 2.2e-04 6.3e-04 1.0e-06 3.3e-07 8.2e-07 2.3e-06 Handling slag

Tc-99 1.9e-02 0.0e+00 0.0e+00 7.6e-02 6.9e-05 0.0e+00 0.0e+00 2.8e-04 Leachate-industrial-scrap

Ru-103 1.1e-01 2.3e-02 7.1e-02 3.5e-01 4.2e-04 8.4e-05 2.6e-04 1.3e-03 Scrap yard

Ru-106 7.8e-02 1.7e-02 4.9e-02 2.4e-01 2.9e-04 6.2e-05 1.8e-04 8.8e-04 Scrap yard

a

 5th percentile to 95th percentile = 90% confidence interval
Chapter 4 Recycling and Disposal of Copper Scrap

Table 4.11 Normalized mass-based effective doses to critical groups for copper

Radionuclide

:Sv/y per Bq/g mrem/y per pCi/g

Mean

Percentilea

Mean

Percentilea

Scenario

5th 50th 95th 5th 50th 95th

4-37 NUREG-1640

Ag-108m 5.4e-01 1.2e-01 3.4e-01 1.7e+00 2.0e-03 4.3e-04 1.3e-03 6.1e-03 Scrap yard

Ag-110m 9.6e-01 2.0e-01 6.1e-01 2.9e+00 3.6e-03 7.5e-04 2.3e-03 1.1e-02 Scrap yard

Cd-109 8.0e-04 2.7e-04 6.6e-04 1.8e-03 3.0e-06 1.0e-06 2.4e-06 6.6e-06 Handling slag

Sn-113 8.8e-02 3.1e-02 7.3e-02 1.9e-01 3.3e-04 1.1e-04 2.7e-04 7.2e-04 Handling slag

Sb-124 5.7e-01 1.2e-01 3.6e-01 1.8e+00 2.1e-03 4.4e-04 1.3e-03 6.5e-03 Scrap yard

Sb-125 1.5e-01 5.1e-02 1.3e-01 3.5e-01 5.7e-04 1.9e-04 4.6e-04 1.3e-03 Handling slag

Te-123m 1.3e-02 2.8e-03 8.4e-03 4.1e-02 4.9e-05 1.0e-05 3.1e-05 1.5e-04 Scrap yard

Te-127m 1.5e-03 3.4e-04 9.4e-04 4.5e-03 5.5e-06 1.3e-06 3.5e-06 1.7e-05 Scrap yard

I-125 2.0e-03 4.1e-04 1.5e-03 5.1e-03 7.2e-06 1.5e-06 5.4e-06 1.9e-05 Handling slag

I-129 5.9e-01 0.0e+00 0.0e+00 2.1e+00 2.2e-03 0.0e+00 0.0e+00 7.9e-03 Leachate-industrial-scrap

I-131 3.6e-02 3.5e-03 2.1e-02 1.2e-01 1.3e-04 1.3e-05 7.7e-05 4.4e-04 Handling slag

Cs-134 5.4e-01 1.2e-01 3.4e-01 1.7e+00 2.0e-03 4.3e-04 1.3e-03 6.1e-03 Scrap yard

Cs-135 8.4e-05 1.1e-05 5.3e-05 2.7e-04 3.1e-07 4.2e-08 2.0e-07 9.8e-07 Scrap yard

Cs-137 2.0e-01 4.2e-02 1.2e-01 6.0e-01 7.3e-04 1.6e-04 4.6e-04 2.2e-03 Scrap yard

Ba-133 1.5e-01 5.2e-02 1.2e-01 3.2e-01 5.5e-04 1.9e-04 4.6e-04 1.2e-03 Handling slag

Ce-139 2.8e-02 9.8e-03 2.3e-02 6.1e-02 1.0e-04 3.6e-05 8.6e-05 2.3e-04 Handling slag

Ce-141 8.9e-03 2.8e-03 7.1e-03 2.1e-02 3.3e-05 1.0e-05 2.6e-05 7.6e-05 Handling slag

Ce-144 2.5e-02 8.8e-03 2.1e-02 5.3e-02 9.1e-05 3.3e-05 7.6e-05 2.0e-04 Handling slag

Pm-147 2.7e-04 8.6e-05 2.2e-04 6.3e-04 1.0e-06 3.2e-07 8.1e-07 2.3e-06 Handling slag

Sm-151 2.1e-04 6.5e-05 1.7e-04 4.9e-04 7.7e-07 2.4e-07 6.2e-07 1.8e-06 Handling slag

Eu-152 5.9e-01 2.1e-01 4.9e-01 1.3e+00 2.2e-03 7.7e-04 1.8e-03 4.8e-03 Handling slag

Eu-154 5.8e-01 2.0e-01 4.8e-01 1.3e+00 2.1e-03 7.5e-04 1.8e-03 4.7e-03 Handling slag

Eu-155 5.6e-03 2.0e-03 4.6e-03 1.2e-02 2.1e-05 7.4e-06 1.7e-05 4.5e-05 Handling slag

Gd-153 6.4e-03 2.2e-03 5.3e-03 1.4e-02 2.4e-05 8.3e-06 2.0e-05 5.1e-05 Handling slag

Tb-160 4.7e-01 1.6e-01 3.9e-01 1.1e+00 1.8e-03 6.0e-04 1.4e-03 3.9e-03 Handling slag

Tm-170 9.1e-04 3.2e-04 7.5e-04 2.0e-03 3.4e-06 1.2e-06 2.8e-06 7.3e-06 Handling slag

Tm-171 1.0e-04 3.5e-05 8.3e-05 2.3e-04 3.7e-07 1.3e-07 3.1e-07 8.4e-07 Handling slag

Ta-182 5.7e-01 2.0e-01 4.7e-01 1.3e+00 2.1e-03 7.4e-04 1.8e-03 4.7e-03 Handling slag

W-181 1.4e-03 4.8e-04 1.1e-03 3.0e-03 5.1e-06 1.8e-06 4.2e-06 1.1e-05 Handling slag

W-185 7.8e-05 2.0e-05 6.0e-05 1.9e-04 2.9e-07 7.3e-08 2.2e-07 7.1e-07 Handling slag

Os-185 2.0e-01 4.1e-02 1.2e-01 6.0e-01 7.3e-04 1.5e-04 4.6e-04 2.2e-03 Scrap yard

Ir-192 1.9e-01 3.9e-02 1.2e-01 5.8e-01 7.0e-04 1.4e-04 4.4e-04 2.1e-03 Scrap yard

Tl-204 2.0e-04 5.0e-05 1.3e-04 6.0e-04 7.5e-07 1.9e-07 4.8e-07 2.2e-06 Scrap yard

Pb-210 2.4e-01 4.2e-02 1.8e-01 6.2e-01 8.8e-04 1.6e-04 6.6e-04 2.3e-03 Handling slag

Bi-207 5.5e-01 1.2e-01 3.4e-01 1.7e+00 2.0e-03 4.3e-04 1.3e-03 6.2e-03 Scrap yard

Po-210 3.7e-02 1.0e-02 2.4e-02 1.1e-01 1.4e-04 3.8e-05 8.7e-05 4.2e-04 Scrap yard

Ra-226 1.1e+00 4.0e-01 9.3e-01 2.4e+00 4.1e-03 1.5e-03 3.4e-03 8.8e-03 Handling slag

Ra-228 7.3e-01 2.6e-01 6.1e-01 1.6e+00 2.7e-03 9.7e-04 2.3e-03 5.9e-03 Handling slag

a

 5th percentile to 95th percentile = 90% confidence interval
Recycling and Disposal of Copper Scrap Chapter 4

Table 4.11 Normalized mass-based effective doses to critical groups for copper

Radionuclide

:Sv/y per Bq/g mrem/y per pCi/g

Mean

Percentilea

Mean

Percentilea

Scenario

5th 50th 95th 5th 50th 95th

NUREG-1640 4-38

Ac-227 5.1e+00 1.6e+00 4.1e+00 1.2e+01 1.9e-02 5.8e-03 1.5e-02 4.4e-02 Handling slag

Th-228 3.3e+00 1.1e+00 2.7e+00 7.4e+00 1.2e-02 4.1e-03 9.8e-03 2.7e-02 Handling slag

Th-229 4.8e+00 1.5e+00 3.8e+00 1.1e+01 1.8e-02 5.4e-03 1.4e-02 4.1e-02 Handling slag

Th-230 5.5e-01 1.7e-01 4.4e-01 1.3e+00 2.0e-03 6.2e-04 1.6e-03 4.8e-03 Handling slag

Th-232 9.9e-01 3.0e-01 7.9e-01 2.3e+00 3.7e-03 1.1e-03 2.9e-03 8.6e-03 Handling slag

Pa-231 1.4e+00 3.9e-01 9.0e-01 4.4e+00 5.3e-03 1.4e-03 3.3e-03 1.6e-02 Scrap yard

U-232 2.0e+00 6.2e-01 1.6e+00 4.8e+00 7.5e-03 2.3e-03 6.0e-03 1.8e-02 Handling slag

U-233 5.2e-01 1.6e-01 4.1e-01 1.2e+00 1.9e-03 5.8e-04 1.5e-03 4.5e-03 Handling slag

U-234 5.1e-01 1.5e-01 4.1e-01 1.2e+00 1.9e-03 5.7e-04 1.5e-03 4.5e-03 Handling slag

U-235 5.1e-01 1.6e-01 4.1e-01 1.2e+00 1.9e-03 6.0e-04 1.5e-03 4.4e-03 Handling slag

U-236 4.7e-01 1.4e-01 3.8e-01 1.1e+00 1.7e-03 5.3e-04 1.4e-03 4.1e-03 Handling slag

U-238 4.4e-01 1.4e-01 3.5e-01 1.0e+00 1.6e-03 5.0e-04 1.3e-03 3.8e-03 Handling slag

Np-237 1.2e+00 3.9e-01 9.8e-01 2.8e+00 4.5e-03 1.4e-03 3.6e-03 1.1e-02 Handling slag

Pu-236 6.3e-01 2.0e-01 5.0e-01 1.5e+00 2.3e-03 7.2e-04 1.9e-03 5.5e-03 Handling slag

Pu-238 8.5e-01 2.6e-01 6.8e-01 2.0e+00 3.2e-03 9.7e-04 2.5e-03 7.4e-03 Handling slag

Pu-239 6.5e-01 2.0e-01 5.2e-01 1.5e+00 2.4e-03 7.5e-04 1.9e-03 5.7e-03 Handling slag

Pu-240 6.5e-01 2.0e-01 5.2e-01 1.5e+00 2.4e-03 7.5e-04 1.9e-03 5.7e-03 Handling slag

Pu-241 9.4e-03 2.5e-03 5.9e-03 2.8e-02 3.5e-05 9.3e-06 2.2e-05 1.1e-04 Scrap yard

Pu-242 6.1e-01 1.9e-01 4.9e-01 1.4e+00 2.2e-03 7.0e-04 1.8e-03 5.3e-03 Handling slag

Pu-244 7.5e-01 2.6e-01 6.1e-01 1.7e+00 2.8e-03 9.5e-04 2.3e-03 6.3e-03 Handling slag

Am-241 2.1e+00 6.3e-01 1.6e+00 4.8e+00 7.6e-03 2.3e-03 6.1e-03 1.8e-02 Handling slag

Am-242m 2.1e+00 6.5e-01 1.7e+00 5.0e+00 7.9e-03 2.4e-03 6.3e-03 1.9e-02 Handling slag

Am-243 2.1e+00 6.5e-01 1.7e+00 4.9e+00 7.8e-03 2.4e-03 6.2e-03 1.8e-02 Handling slag

Cm-242 2.5e-01 7.7e-02 2.0e-01 6.0e-01 9.4e-04 2.9e-04 7.5e-04 2.2e-03 Handling slag

Cm-243 1.6e+00 4.8e-01 1.2e+00 3.6e+00 5.7e-03 1.8e-03 4.6e-03 1.3e-02 Handling slag

Cm-244 1.3e+00 3.9e-01 1.0e+00 3.0e+00 4.8e-03 1.5e-03 3.8e-03 1.1e-02 Handling slag

Cm-245 2.1e+00 6.3e-01 1.6e+00 4.9e+00 7.6e-03 2.3e-03 6.1e-03 1.8e-02 Handling slag

Cm-246 2.1e+00 6.3e-01 1.6e+00 4.8e+00 7.6e-03 2.3e-03 6.1e-03 1.8e-02 Handling slag

Cm-247 2.0e+00 6.5e-01 1.6e+00 4.8e+00 7.6e-03 2.4e-03 6.1e-03 1.8e-02 Handling slag

Cm-248 7.2e+00 2.2e+00 5.8e+00 1.7e+01 2.7e-02 8.2e-03 2.1e-02 6.3e-02 Handling slag

Bk-249 7.7e-03 2.4e-03 6.1e-03 1.8e-02 2.8e-05 8.7e-06 2.3e-05 6.7e-05 Handling slag

Cf-248 4.4e-01 1.3e-01 3.5e-01 1.0e+00 1.6e-03 5.0e-04 1.3e-03 3.9e-03 Handling slag

Cf-249 3.6e+00 1.1e+00 2.9e+00 8.3e+00 1.3e-02 4.1e-03 1.1e-02 3.1e-02 Handling slag

Cf-250 1.7e+00 5.1e-01 1.3e+00 3.9e+00 6.2e-03 1.9e-03 4.9e-03 1.5e-02 Handling slag

Cf-251 3.5e+00 1.1e+00 2.8e+00 8.3e+00 1.3e-02 4.0e-03 1.0e-02 3.1e-02 Handling slag

Cf-252 9.7e-01 3.0e-01 7.7e-01 2.3e+00 3.6e-03 1.1e-03 2.9e-03 8.5e-03 Handling slag

Cf-254 8.7e+00 3.1e+00 7.2e+00 1.9e+01 3.2e-02 1.1e-02 2.7e-02 7.1e-02 Handling slag

Es-254 8.9e-01 3.3e-01 7.4e-01 1.9e+00 3.3e-03 1.2e-03 2.7e-03 7.2e-03 Handling slag

a

 5th percentile to 95th percentile = 90% confidence interval
Chapter 4 Recycling and Disposal of Copper Scrap

4-39 NUREG-1640

Table 4.12 Normalized surficial effective doses to critical groups for copper

Radionuclide

:Sv/y per Bq/cm2 mrem/y per pCi/cm2

Scenario

Mean

Percentilea

Mean

Percentilea

5th 50th 95th 5th 50th 95th

H-3 2.0e-04 0.0e+00 1.5e-07 8.5e-04 7.6e-07 0.0e+00 5.6e-10 3.1e-06 Leachate-industrial-scrap

C-14 4.8e-04 1.5e-04 3.6e-04 1.2e-03 1.8e-06 5.4e-07 1.3e-06 4.6e-06 Airborne emissions

Na-22 2.2e+00 7.6e-01 1.8e+00 4.9e+00 8.2e-03 2.8e-03 6.8e-03 1.8e-02 Handling slag

P-32 1.5e-03 2.3e-04 8.9e-04 4.9e-03 5.6e-06 8.7e-07 3.3e-06 1.8e-05 Scrap yard

S-35 8.1e-05 1.7e-05 6.0e-05 2.2e-04 3.0e-07 6.2e-08 2.2e-07 8.0e-07 Handling slag

Cl-36 4.5e-03 0.0e+00 0.0e+00 1.8e-02 1.7e-05 0.0e+00 0.0e+00 6.6e-05 Leachate-industrial-scrap

K-40 1.3e-01 2.7e-02 7.9e-02 3.7e-01 4.6e-04 9.8e-05 2.9e-04 1.4e-03 Scrap yard

Ca-41 1.9e-03 0.0e+00 0.0e+00 7.8e-03 6.9e-06 0.0e+00 0.0e+00 2.9e-05 Leachate-industrial-scrap

Ca-45 4.8e-04 1.4e-04 3.8e-04 1.1e-03 1.8e-06 5.3e-07 1.4e-06 4.1e-06 Handling slag

Sc-46 1.8e+00 6.0e-01 1.5e+00 3.9e+00 6.5e-03 2.2e-03 5.4e-03 1.5e-02 Handling slag

Cr-51 1.5e-02 4.5e-03 1.2e-02 3.7e-02 5.7e-05 1.7e-05 4.5e-05 1.4e-04 Handling slag

Mn-53 1.2e-05 3.0e-06 9.5e-06 3.0e-05 4.5e-08 1.1e-08 3.5e-08 1.1e-07 Handling slag

Mn-54 8.2e-01 2.8e-01 6.8e-01 1.8e+00 3.0e-03 1.0e-03 2.5e-03 6.7e-03 Handling slag

Fe-55 1.2e-04 2.7e-05 8.9e-05 2.9e-04 4.3e-07 1.0e-07 3.3e-07 1.1e-06 Handling slag

Fe-59 8.3e-01 2.7e-01 6.7e-01 1.9e+00 3.1e-03 9.9e-04 2.5e-03 6.9e-03 Handling slag

Co-56 2.5e+00 7.9e-01 2.0e+00 5.5e+00 9.1e-03 2.9e-03 7.4e-03 2.0e-02 Handling slag

Co-57 2.8e-02 9.3e-03 2.3e-02 6.3e-02 1.0e-04 3.4e-05 8.5e-05 2.3e-04 Handling slag

Co-58 6.6e-01 2.1e-01 5.4e-01 1.5e+00 2.5e-03 7.9e-04 2.0e-03 5.6e-03 Handling slag

Co-60 2.1e+00 7.0e-01 1.8e+00 4.8e+00 7.9e-03 2.6e-03 6.5e-03 1.8e-02 Handling slag

Ni-59 3.6e-05 1.1e-05 2.9e-05 8.4e-05 1.3e-07 4.2e-08 1.1e-07 3.1e-07 Handling slag

Ni-63 6.6e-05 1.8e-05 5.1e-05 1.6e-04 2.4e-07 6.6e-08 1.9e-07 5.9e-07 Handling slag

Zn-65 5.2e-01 1.8e-01 4.3e-01 1.1e+00 1.9e-03 6.5e-04 1.6e-03 4.2e-03 Handling slag

As-73 2.7e-04 1.0e-05 8.3e-05 9.4e-04 1.0e-06 3.8e-08 3.1e-07 3.5e-06 Scrap disposal-industrial

Se-75 1.3e-01 2.6e-02 7.9e-02 3.7e-01 4.6e-04 9.7e-05 2.9e-04 1.4e-03 Scrap yard

Sr-85 3.8e-01 1.3e-01 3.1e-01 8.6e-01 1.4e-03 4.7e-04 1.2e-03 3.2e-03 Handling slag

Sr-89 2.2e-03 7.0e-04 1.8e-03 5.1e-03 8.0e-06 2.6e-06 6.5e-06 1.9e-05 Handling slag

Sr-90 1.8e-02 5.6e-03 1.4e-02 4.2e-02 6.7e-05 2.1e-05 5.3e-05 1.6e-04 Handling slag

Y-91 5.8e-03 2.0e-03 4.7e-03 1.3e-02 2.1e-05 7.2e-06 1.7e-05 4.8e-05 Handling slag

Zr-93 1.0e-03 3.2e-04 8.2e-04 2.4e-03 3.8e-06 1.2e-06 3.0e-06 9.0e-06 Handling slag

Zr-95 8.4e-01 2.9e-01 6.9e-01 1.9e+00 3.1e-03 1.1e-03 2.6e-03 6.9e-03 Handling slag

Nb-93m 1.6e-04 4.9e-05 1.3e-04 3.7e-04 5.8e-07 1.8e-07 4.7e-07 1.4e-06 Handling slag

Nb-94 1.6e+00 5.6e-01 1.3e+00 3.6e+00 6.0e-03 2.1e-03 5.0e-03 1.3e-02 Handling slag

Nb-95 5.2e-01 1.6e-01 4.2e-01 1.2e+00 1.9e-03 6.0e-04 1.5e-03 4.5e-03 Handling slag

Mo-93 2.4e-03 0.0e+00 0.0e+00 2.7e-03 8.8e-06 0.0e+00 0.0e+00 1.0e-05 Leachate-industrial-scrap

Tc-97 3.9e-03 0.0e+00 0.0e+00 1.6e-02 1.4e-05 0.0e+00 0.0e+00 5.8e-05 Leachate-industrial-scrap

Tc-97m 5.3e-04 1.7e-04 4.3e-04 1.2e-03 2.0e-06 6.2e-07 1.6e-06 4.6e-06 Handling slag

Tc-99 3.6e-02 0.0e+00 0.0e+00 1.5e-01 1.3e-04 0.0e+00 0.0e+00 5.4e-04 Leachate-industrial-scrap

Ru-103 2.2e-01 4.4e-02 1.4e-01 6.7e-01 8.1e-04 1.6e-04 5.1e-04 2.5e-03 Scrap yard

Ru-106 1.5e-01 3.2e-02 9.6e-02 4.5e-01 5.6e-04 1.2e-04 3.5e-04 1.7e-03 Scrap yard

a

 5th percentile to 95th percentile = 90% confidence interval
Recycling and Disposal of Copper Scrap Chapter 4

Table 4.12 Normalized surficial effective doses to critical groups for copper

Radionuclide

:Sv/y per Bq/cm2 mrem/y per pCi/cm2

Scenario

Mean

Percentilea

Mean

Percentilea

5th 50th 95th 5th 50th 95th

NUREG-1640 4-40

Ag-108m 1.1e+00 2.2e-01 6.7e-01 3.1e+00 3.9e-03 8.2e-04 2.5e-03 1.2e-02 Scrap yard

Ag-110m 1.9e+00 3.9e-01 1.2e+00 5.5e+00 6.9e-03 1.5e-03 4.4e-03 2.0e-02 Scrap yard

Cd-109 1.6e-03 5.2e-04 1.3e-03 3.5e-03 5.8e-06 1.9e-06 4.7e-06 1.3e-05 Handling slag

Sn-113 1.7e-01 5.8e-02 1.4e-01 3.8e-01 6.3e-04 2.2e-04 5.2e-04 1.4e-03 Handling slag

Sb-124 1.1e+00 2.3e-01 7.0e-01 3.3e+00 4.1e-03 8.5e-04 2.6e-03 1.2e-02 Scrap yard

Sb-125 3.0e-01 9.7e-02 2.4e-01 6.8e-01 1.1e-03 3.6e-04 8.9e-04 2.5e-03 Handling slag

Te-123m 2.6e-02 5.4e-03 1.6e-02 7.7e-02 9.6e-05 2.0e-05 6.0e-05 2.8e-04 Scrap yard

Te-127m 2.9e-03 6.5e-04 1.8e-03 8.6e-03 1.1e-05 2.4e-06 6.7e-06 3.2e-05 Scrap yard

I-125 3.8e-03 7.8e-04 2.8e-03 9.9e-03 1.4e-05 2.9e-06 1.0e-05 3.6e-05 Handling slag

I-129 1.2e+00 0.0e+00 0.0e+00 4.0e+00 4.3e-03 0.0e+00 0.0e+00 1.5e-02 Leachate-industrial-scrap

I-131 6.9e-02 6.7e-03 4.0e-02 2.3e-01 2.6e-04 2.5e-05 1.5e-04 8.5e-04 Handling slag

Cs-134 1.1e+00 2.2e-01 6.7e-01 3.1e+00 3.9e-03 8.2e-04 2.5e-03 1.1e-02 Scrap yard

Cs-135 1.6e-04 2.2e-05 1.0e-04 5.1e-04 6.0e-07 8.0e-08 3.8e-07 1.9e-06 Scrap yard

Cs-137 3.8e-01 8.1e-02 2.4e-01 1.1e+00 1.4e-03 3.0e-04 8.9e-04 4.2e-03 Scrap yard

Ba-133 2.9e-01 9.9e-02 2.4e-01 6.3e-01 1.1e-03 3.6e-04 8.8e-04 2.3e-03 Handling slag

Ce-139 5.4e-02 1.9e-02 4.5e-02 1.2e-01 2.0e-04 6.9e-05 1.7e-04 4.4e-04 Handling slag

Ce-141 1.7e-02 5.3e-03 1.4e-02 4.0e-02 6.4e-05 2.0e-05 5.1e-05 1.5e-04 Handling slag

Ce-144 4.8e-02 1.7e-02 4.0e-02 1.0e-01 1.8e-04 6.2e-05 1.5e-04 3.9e-04 Handling slag

Pm-147 5.2e-04 1.7e-04 4.2e-04 1.2e-03 1.9e-06 6.1e-07 1.6e-06 4.5e-06 Handling slag

Sm-151 4.0e-04 1.2e-04 3.2e-04 9.5e-04 1.5e-06 4.6e-07 1.2e-06 3.5e-06 Handling slag

Eu-152 1.1e+00 3.9e-01 9.5e-01 2.5e+00 4.2e-03 1.5e-03 3.5e-03 9.3e-03 Handling slag

Eu-154 1.1e+00 3.8e-01 9.3e-01 2.5e+00 4.2e-03 1.4e-03 3.4e-03 9.1e-03 Handling slag

Eu-155 1.1e-02 3.8e-03 8.9e-03 2.4e-02 4.0e-05 1.4e-05 3.3e-05 8.7e-05 Handling slag

Gd-153 1.2e-02 4.3e-03 1.0e-02 2.7e-02 4.6e-05 1.6e-05 3.8e-05 1.0e-04 Handling slag

Tb-160 9.2e-01 3.1e-01 7.5e-01 2.1e+00 3.4e-03 1.1e-03 2.8e-03 7.6e-03 Handling slag

Tm-170 1.8e-03 6.1e-04 1.4e-03 3.9e-03 6.5e-06 2.3e-06 5.3e-06 1.4e-05 Handling slag

Tm-171 2.0e-04 6.6e-05 1.6e-04 4.4e-04 7.2e-07 2.4e-07 5.9e-07 1.6e-06 Handling slag

Ta-182 1.1e+00 3.8e-01 9.1e-01 2.5e+00 4.1e-03 1.4e-03 3.4e-03 9.1e-03 Handling slag

W-181 2.7e-03 9.2e-04 2.2e-03 6.0e-03 9.9e-06 3.4e-06 8.2e-06 2.2e-05 Handling slag

W-185 1.5e-04 3.8e-05 1.2e-04 3.8e-04 5.6e-07 1.4e-07 4.3e-07 1.4e-06 Handling slag

Os-185 3.8e-01 8.0e-02 2.4e-01 1.1e+00 1.4e-03 2.9e-04 8.9e-04 4.2e-03 Scrap yard

Ir-192 3.6e-01 7.6e-02 2.3e-01 1.1e+00 1.3e-03 2.8e-04 8.5e-04 4.1e-03 Scrap yard

Tl-204 3.9e-04 9.7e-05 2.5e-04 1.2e-03 1.4e-06 3.6e-07 9.2e-07 4.4e-06 Scrap yard

Pb-210 4.6e-01 8.0e-02 3.5e-01 1.2e+00 1.7e-03 3.0e-04 1.3e-03 4.5e-03 Handling slag

Bi-207 1.1e+00 2.2e-01 6.7e-01 3.1e+00 3.9e-03 8.3e-04 2.5e-03 1.2e-02 Scrap yard

Po-210 7.2e-02 2.0e-02 4.5e-02 2.2e-01 2.7e-04 7.3e-05 1.7e-04 8.2e-04 Scrap yard

Ra-226 2.1e+00 7.7e-01 1.8e+00 4.7e+00 7.9e-03 2.8e-03 6.6e-03 1.7e-02 Handling slag

Ra-228 1.4e+00 5.0e-01 1.2e+00 3.1e+00 5.2e-03 1.9e-03 4.3e-03 1.2e-02 Handling slag

a

 5th percentile to 95th percentile = 90% confidence interval
Chapter 4 Recycling and Disposal of Copper Scrap

Table 4.12 Normalized surficial effective doses to critical groups for copper

Radionuclide

:Sv/y per Bq/cm2 mrem/y per pCi/cm2

Scenario

Mean

Percentilea

Mean

Percentilea

5th 50th 95th 5th 50th 95th

4-41 NUREG-1640

Ac-227 9.8e+00 3.0e+00 7.8e+00 2.3e+01 3.6e-02 1.1e-02 2.9e-02 8.5e-02 Handling slag

Th-228 6.3e+00 2.1e+00 5.1e+00 1.5e+01 2.3e-02 7.7e-03 1.9e-02 5.4e-02 Handling slag

Th-229 9.2e+00 2.8e+00 7.4e+00 2.2e+01 3.4e-02 1.0e-02 2.7e-02 8.1e-02 Handling slag

Th-230 1.1e+00 3.2e-01 8.5e-01 2.5e+00 3.9e-03 1.2e-03 3.1e-03 9.3e-03 Handling slag

Th-232 1.9e+00 5.9e-01 1.5e+00 4.6e+00 7.1e-03 2.2e-03 5.6e-03 1.7e-02 Handling slag

Pa-231 2.8e+00 7.4e-01 1.7e+00 8.5e+00 1.0e-02 2.7e-03 6.4e-03 3.1e-02 Scrap yard

U-232 3.9e+00 1.2e+00 3.1e+00 9.3e+00 1.4e-02 4.4e-03 1.1e-02 3.5e-02 Handling slag

U-233 1.0e+00 3.0e-01 8.0e-01 2.4e+00 3.7e-03 1.1e-03 2.9e-03 8.8e-03 Handling slag

U-234 9.9e-01 3.0e-01 7.8e-01 2.3e+00 3.7e-03 1.1e-03 2.9e-03 8.7e-03 Handling slag

U-235 9.9e-01 3.1e-01 7.9e-01 2.3e+00 3.7e-03 1.1e-03 2.9e-03 8.6e-03 Handling slag

U-236 9.1e-01 2.8e-01 7.3e-01 2.2e+00 3.4e-03 1.0e-03 2.7e-03 8.0e-03 Handling slag

U-238 8.5e-01 2.6e-01 6.8e-01 2.0e+00 3.2e-03 9.7e-04 2.5e-03 7.5e-03 Handling slag

Np-237 2.4e+00 7.4e-01 1.9e+00 5.5e+00 8.7e-03 2.7e-03 7.0e-03 2.0e-02 Handling slag

Pu-236 1.2e+00 3.8e-01 9.7e-01 2.9e+00 4.5e-03 1.4e-03 3.6e-03 1.1e-02 Handling slag

Pu-238 1.7e+00 5.1e-01 1.3e+00 3.9e+00 6.1e-03 1.9e-03 4.9e-03 1.4e-02 Handling slag

Pu-239 1.3e+00 3.9e-01 1.0e+00 3.0e+00 4.7e-03 1.4e-03 3.7e-03 1.1e-02 Handling slag

Pu-240 1.3e+00 3.9e-01 1.0e+00 3.0e+00 4.7e-03 1.4e-03 3.7e-03 1.1e-02 Handling slag

Pu-241 1.8e-02 4.8e-03 1.1e-02 5.5e-02 6.7e-05 1.8e-05 4.2e-05 2.0e-04 Scrap yard

Pu-242 1.2e+00 3.6e-01 9.4e-01 2.8e+00 4.4e-03 1.3e-03 3.5e-03 1.0e-02 Handling slag

Pu-244 1.5e+00 4.9e-01 1.2e+00 3.3e+00 5.4e-03 1.8e-03 4.4e-03 1.2e-02 Handling slag

Am-241 4.0e+00 1.2e+00 3.2e+00 9.4e+00 1.5e-02 4.5e-03 1.2e-02 3.5e-02 Handling slag

Am-242m 4.1e+00 1.2e+00 3.3e+00 9.8e+00 1.5e-02 4.6e-03 1.2e-02 3.6e-02 Handling slag

Am-243 4.1e+00 1.2e+00 3.2e+00 9.6e+00 1.5e-02 4.6e-03 1.2e-02 3.5e-02 Handling slag

Cm-242 4.9e-01 1.5e-01 3.9e-01 1.2e+00 1.8e-03 5.5e-04 1.4e-03 4.3e-03 Handling slag

Cm-243 3.0e+00 9.2e-01 2.4e+00 7.1e+00 1.1e-02 3.4e-03 8.8e-03 2.6e-02 Handling slag

Cm-244 2.5e+00 7.6e-01 2.0e+00 5.9e+00 9.2e-03 2.8e-03 7.3e-03 2.2e-02 Handling slag

Cm-245 4.0e+00 1.2e+00 3.2e+00 9.5e+00 1.5e-02 4.5e-03 1.2e-02 3.5e-02 Handling slag

Cm-246 4.0e+00 1.2e+00 3.2e+00 9.4e+00 1.5e-02 4.5e-03 1.2e-02 3.5e-02 Handling slag

Cm-247 4.0e+00 1.2e+00 3.2e+00 9.3e+00 1.5e-02 4.6e-03 1.2e-02 3.4e-02 Handling slag

Cm-248 1.4e+01 4.2e+00 1.1e+01 3.3e+01 5.2e-02 1.6e-02 4.1e-02 1.2e-01 Handling slag

Bk-249 1.5e-02 4.5e-03 1.2e-02 3.5e-02 5.5e-05 1.7e-05 4.4e-05 1.3e-04 Handling slag

Cf-248 8.6e-01 2.6e-01 6.8e-01 2.0e+00 3.2e-03 9.6e-04 2.5e-03 7.5e-03 Handling slag

Cf-249 6.9e+00 2.1e+00 5.5e+00 1.6e+01 2.6e-02 7.9e-03 2.0e-02 6.0e-02 Handling slag

Cf-250 3.2e+00 9.8e-01 2.6e+00 7.6e+00 1.2e-02 3.6e-03 9.5e-03 2.8e-02 Handling slag

Cf-251 6.8e+00 2.1e+00 5.4e+00 1.6e+01 2.5e-02 7.7e-03 2.0e-02 6.0e-02 Handling slag

Cf-252 1.9e+00 5.7e-01 1.5e+00 4.5e+00 7.0e-03 2.1e-03 5.5e-03 1.6e-02 Handling slag

Cf-254 1.7e+01 5.8e+00 1.4e+01 3.8e+01 6.2e-02 2.1e-02 5.1e-02 1.4e-01 Handling slag

Es-254 1.7e+00 6.2e-01 1.4e+00 3.8e+00 6.4e-03 2.3e-03 5.3e-03 1.4e-02 Handling slag

a

 5th percentile to 95th percentile = 90% confidence interval
Recycling and Disposal of Copper Scrap Chapter 4

NUREG-1640 4-42

References

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Copper. Atlanta: U.S. Department of Health and Human Services, Public Health Services.

Anigstein, R., et al. 2001. “Technical Support Document: Potential Recycling of Scrap Metal

from Nuclear Facilities, Part I: Radiological Assessment of Exposed Individuals.” Washington,

DC: U.S. Environmental Protection Agency, Office of Radiation and Indoor Air. 

http://www.epa.gov/radiation/cleanmetals/docs/tsd (August 12, 2002).

Biswas, A. K., and W. G. Davenport. 1976. Extractive Metallurgy of Copper. Oxford: Pergamon

Press. 

Brunson, W. W., and D. R. Stone. 1976. “Electrorefining at the Copper Division of Southwire

Company, Carrollton, Georgia, U.S.A.” Transactions of the Institution of Mining and

Metallurgy, Section C, vol. 85, C150–C156. 

Bryan, R. H., and I. T. Dudley. 1974. “Estimated Quantities of Materials Contained in a 1000-

MW(e) PWR Power Plant,” ORNL-TM-4515. Oak Ridge, TN: Oak Ridge National Laboratory.

Bureau of the Census (U.S.). 1999. “1997 Economic Census: Transportation—1997 Commodity

Flow Survey.” U.S. Department of Transportation, Bureau of Transportation Statistics; U.S.

Department of Commerce, Economics and Statistics Administration.

http://199.79.179.77/ntda/cfs/97tcf-us.pdf (March 4, 2002).

CDA (Copper Development Association) 2001. “Annual Data 2001: Copper Supply &

Consumption, 1980–2000.” http://marketdata.copper.org/annual_00/annual_00.pdf

(March 25, 2003).

Code of Federal Regulations, Title 29, Labor, Part 1910, “Occupational Safety and Health

Standards,” Subpart Z, “Toxic and Hazardous Substances,” 1910.1000, “Air Contaminants,”

Table Z-1, “Limits for Air Contaminants” (29 CFR 1910.1000). 

http://www.a c c e s s .g p o.g ov / n a r a / c f r / w a i s i d x _ 01/ 2 9 c f r 19 10a _ 01.h t m l 

 (March 18, 2003).

Davenport, W. G. 1986. “Copper Production.” In M. B. Bever (Ed.), Encyclopedia of Materials

Science and Engineering. Vol 2 (pp. 841-848). Oxford: Pergamon Press.

Edelstein, D. E. 2002. “Copper.” In Minerals Yearbook—2000. U.S. Geological Survey

http://minerals.usgs.gov/minerals/pubs/commodity/copper/240400.pdf (March 3, 2003).

Environmental Protection Agency (U.S.) (EPA). 1995. “Compilation of Air Pollutant Emission

Factors,” AP-42. 5th ed. Vol. 1, “Stationary Point and Area Sources.” Washington DC: Author.

http://www.epa.gov/ttn/chief/ap42/ch12/final/c12s09.pdf (March 3, 2003).
Chapter 4 Recycling and Disposal of Copper Scrap

4-43 NUREG-1640

Environmental Protection Agency (U.S.) (EPA). 2002. "Zinc Fertilizers Made from Recycled

Hazardous Secondary Materials." Federal Register, Vol. 67, No. 142: pp. 48393–48415.

July 24, 2002. 

Gößling, S. 2001. “Entropy Balance of Industrial Copper Production: A Measure for Resource

Use: First Results for Flash Smelting, Converting and Refining.” 

http://www.desy.de/~stefang/beschreibung.html (September 13, 2000).

Henstock, M. E. 1997. “The Potential and the Limitations of Copper Recycling.” Proceedings of

The World Conference on Copper Recycling. Lisbon: International Copper Study Group.

International Copper Association (ICA). (n/d). “Copper Info.”

http://www.copperinfo.com/cproducts/transportation.shtml (October 7, 2002).

Jolly, J. L. W. 1997. “World Copper Scrap Markets and Trends.” Proceedings of The World

Conference on Copper Recycling. Lisbon: International Copper Study Group.

Kusik, C. L., and C. B. Kenahan. 1978. “Energy Use Patterns for Metal Recycling,” Information

Circular 8781. U.S. Bureau of Mines. 

Licht, C. A. 2000. “Secondary Brass and Bronze Melting Processes.” In W. T. Davis (Ed.), Air

Pollution Engineering Manual, 2nd ed. (pp. 626–631). New York: John Wiley & Sons, Inc.

Pacific Environmental Services, Inc. (PES) 1977. “Emission Factors and Emission Source

Information for Primary and Secondary Copper Smelters,” EPA-450/3-77-051. Research

Triangle Park, NC: U.S. Environmental Protection Agency.

Ramachandran, V., and V. L. Wildman. 1987. “Current Operations at the Amarillo Copper

Refinery.” In J. E. Hoffman et al. (Eds.), The Electrorefining and Winning of Copper (pp.

387–396). Warrendale, PA: The Metallurgical Society/AIME. 

St. John, H. M. 1958. Brass and Bronze Foundry Practice. Cleveland, OH: Penton Publishing

Company.

Stone, D. R., and J. P. Tuggle. 1995. “Process, Productivity, and Quality Improvements at the

Copper Division of Southwire” In Proceedings of Copper 95-Cobre 95 International

Conference: Vol. 3. Electrorefining and Hydrometallurgy of Copper (pp. 103–111). The

Metallurgical Society of CIM.

“Trends in U.S. Copper and Scrap and Effects of Product Shifts.” 1997. Presented at The World

Conference on Copper Recycling, Brussels (March 3–4, 1997).

http://environment.copper.org/trends/Scrap.html (October 7, 2002).

U.S. Geological Survey (USGS). 2001. “Copper.” In “Mineral Commodity Summaries, January

2001.” http://minerals.usgs.gov/minerals/pubs/commodity/copper/240301.pdf (March 3, 2003).
Chapter 5 Recycling and Disposal of Aluminum Scrap

5-1 NUREG-1640

Assessments have been performed of the potential radiation doses to individuals from the recycling or

disposal of aluminum scrap that could be cleared from nuclear facilities. The assessment addresses 21

scenarios that depict exposures resulting from the handling and processing of cleared scrap and the

products of melt-refining this scrap at secondary aluminum smelters, emission of airborne effluents from

these facilities, transportation of scrap and smelter products, the use of aluminum products, the landfill

disposal of cleared scrap and aluminum dross, and the infiltration of well water by leachate from

landfills containing cleared scrap or dross. The analysis utilizes data on secondary aluminum smelters

in the United States, and on contemporary U.S. work practices and living habits.

The critical group for the largest number of radionuclides, accounting for most of the 115 radionuclides

in the analysis, consists of workers processing scrap at a scrap yard. Scenarios involving the use of

aluminum products—the owner-operator of a taxi with an aluminum engine block or a person using an

aluminum cooking utensil—give rise to most of the remaining critical groups.

Mean values of mass-based normalized EDEs to critical groups range from a high of 0.51 :Sv/y per

Bq/g (1.9e-3 mrem/y per pCi/g) from Th-229 to a low of 6.7e-7 :Sv/y per Bq/g (2.5e-9 mrem/y per

pCi/g) from Mn-53. The corresponding surficial EDEs are 0.56 and 7.4e-7 :Sv/y per Bq/cm2

,

respectively. Mean values of mass-based normalized effective doses range from a high of 0.25 :Sv/y

per Bq/g (9.3e-4 mrem/y per pCi/g) from Co-60 to a low of 6.8e-7 :Sv/y per Bq/g (2.5e-9 mrem/y per

pCi/g) from Mn-53. The corresponding surficial effective doses are 0.28 and 7.6e-7 :Sv/y per Bq/cm2

,

respectively. The critical group for Th-229 is the scrap yard workers, for Mn-53 it is the users of

aluminum cooking ware, while for Co-60 it is the drivers of taxis with aluminum engine blocks.

5 RECYCLING AND DISPOSAL OF ALUMINUM SCRAP

This chapter describes the radiological assessment of the recycling and/or disposal of aluminum

scrap that could be cleared from NRC-licensed facilities. This assessment is based on a realistic

appraisal of the recycling of aluminum scrap into consumer or industrial products, or of

disposing of the scrap in an industrial or municipal landfill. 

5.1 Introduction to Analysis

As was the case with the other metals, the evaluation of the potential doses from cleared

aluminum scrap consists of two main parts. The first step is characterizing the flow of cleared

scrap through the normal recycling process, beginning with the generation of scrap, through

melting or smelting, manufacturing, and product use, as well as disposal as an alternative to

recycling. This enables the calculation of radionuclide concentrations in products and byproducts of the smelting of aluminum scrap. 

The second step is the development and analysis of exposure scenarios. All but one of the 21

scenarios in the aluminum analysis were modeled on corresponding scenarios for iron and steel

or copper scrap. The new scenario is discussed in Section 5.6.3.
Recycling and Disposal of Aluminum Scrap Chapter 5

NUREG-1640 5-2

Figure 5.1 Flow of aluminum scrap

5.2 Flow of Aluminum Scrap

This section presents an overview of the U.S. secondary aluminum industry. Its purpose is: 

(1) to serve as a source of information required for the present analysis, and (2) to present a

context for those aspects of the recycling and disposal of aluminum scrap that are addressed by

the analysis. It thus includes some data which are not directly utilized by the analysis.

Figure 5.1 presents a schematic diagram of the flow of aluminum scrap, as characterized in the

present analysis. As is the case in the analysis of other cleared materials, this is a simplified

idealization of the actual process. The diagram depicts the sequence of steps that are represented

by the exposure scenarios in the present analysis. Intermediate steps, not represented by

exposure scenarios, are indicated by dashed lines or boxes. Other steps and processes are

discussed in the following sections of this chapter.
Chapter 5 Recycling and Disposal of Aluminum Scrap

1

 Scrap and smelter products can also be shipped by rail or waterway.

2

 Some scrap is conveyed directly to a smelter and processed at the facility (Gary Huddleston, environmental

manager, Wabash Alloys LLC, private communication with Robert Anigstein, SC&A Inc., October 16, 2002).

3

 Alternate types of processing facilities are discussed in Section 5.2.2.

4

 Processing scrap at the nuclear facility is outside the scope the analysis. Such processing would most likely be

performed by radiation workers whose occupational exposures are controlled under current regulations. 

5-3 NUREG-1640

The process begins with the release of cleared scrap from an NRC-licensed facility. It is

assumed that the scrap is shipped by truck1 for processing at a scrap yard operated by a scrap

metals dealer.2 The scrap dealer then ships the processed scrap to a secondary aluminum

smelter, where it is melt-refined to produce aluminum alloys, which are typically cast into

ingots.3

Alternatively, the licensee or demolition contractor may elect to dispose of the scrap in an

industrial or municipal solid waste (MSW) landfill. As another alternative, depending on the

nature of the scrap and other economic factors, the scrap might be processed at the generator

facility and shipped directly to the smelter.4

Smelter by-products include dross and offgas. Dross, which is analogous to slag in the meltrefining of steel and copper, is a mixture of flux added to the melt, and metallic chlorides and

oxides. The dross is transported by truck for disposal in a landfill. Alternatively, in many cases,

it is sent to processors for metal recovery.

Offgas consists of the fumes and particulates evolved during melting which are captured by the

facility's emission control system. After cooling, most of the offgas is collected in the baghouse

in the form of dust, which is sent to a landfill for disposal. Gases, vapors, and some of the

particulates escape the filtration system and are released to the atmosphere. These airborne

effluents may be transported by air currents to a nearby residence.

The aluminum alloys produced at the smelter are usually shipped in the form of ingots; however,

as discussed on page 5-7, the product may also be shipped as molten metal in insulated crucibles.

Aluminum alloys produced by secondary smelters are used to make a vast array of finished

products. The present analysis examines four such products. Two are generic shapes that can

represent a number of individual products. In addition, two specific products—an aluminum

engine block in an automobile and an aluminum cooking utensil—are included in the analysis.

5.2.1 Sources of Material

As is the case for steel and copper scrap, the main generators of aluminum scrap addressed in

this study are NRC-licensed facilities—primarily commercial power plants, test and research

reactors, and industrial nuclear facilities. According to Bryan and Dudley (1974), a 1000-MWe
Recycling and Disposal of Aluminum Scrap Chapter 5

NUREG-1640 5-4

PWR contains 18.1 t of aluminum. As shown in Table A.10, which presents the results of a

detailed analysis of materials in a PWR, 5.4 t of aluminum is associated with reactor equipment,

reactor auxiliaries, and fuel storage—systems that would most likely be too contaminated to be

candidates for clearance. A total of 10.7 t is associated with site improvements, miscellaneous

buildings, electric plant equipment, and miscellaneous equipment. These systems are not

impacted by radioactive materials and therefore not subject to clearance. This leaves 1.2 to 2.0 t

of aluminum (depending on whether or not the 0.8 t of aluminum in the turbine building falls

into the impacted or nonimpacted category) that would be subject to clearance.

A discussion of the mass-to-surface ratios of the aluminum components of a nuclear power plant

is presented in Section A.6.4. The data in that section describe all of the aluminum components,

while the parameter required for the present analysis is the overall mass-to-surface ratio of the

components likely to be cleared. A probability distribution of mass-to-surface ratios of the

cleared scrap was determined as follows. As stated in Section A.6.4, most of the aluminum is

assumed to be in the form of sheet metal or thin-walled tubing, ranging in thickness from 0.062

to 0.25 inch (0.159 – 0.635 cm). It is assumed that the individual components are equally likely

to have one of eight standard thicknesses of commercial aluminum sheets in this range, as shown

in Table 5.1. The overall mass-to-surface ratio is generated by randomly assigning a frequency

(uniformly distributed over the arbitrary range 0 – 1) to each thickness. We then calculate a

frequency-weighted-average thickness, from which we obtain the mass-to-surface ratio. The

results of 10,000 Monte Carlo realizations have a mean value of 0.90 g/cm2

 and a coefficient of

variability of 0.10.

Table 5.1 Mass-to-surface ratios of commercial aluminum sheets

Thicknessa

Mass-to-surface

ratio (g/cm2

)

b inch cm

0.063 0.160 0.432

0.08 0.203 0.549

0.09 0.229 0.617

0.1 0.254 0.686

0.125 0.318 0.857

0.16 0.406 1.097

0.19 0.483 1.303

0.25 0.635 1.715

a

 Sizes listed for 5052-H32 aluminum flat sheet, a common alloy (Cygnet [n/d]) b

 Calculated, assuming density = 2.7 g/cm3

5.2.2 Recycling of Aluminum Scrap

Section 3.2.2 describes the three types of scrap metal used in iron- and steelmaking: home, new,

and old. Aluminum scrap falls into the same three categories. Just as the other metals,

aluminum scrap cleared from NRC-licensed facilities would be old scrap. Statistical data on the

consumption of aluminum scrap and its recovery in aluminum products are presented in
Chapter 5 Recycling and Disposal of Aluminum Scrap

5

 Nicholas A. Adams, Jr., Director, Statistics & Economics and Staff Executive, Recycling Division, The

Aluminum Association, Incorporated, private communication with Robert Anigstein, SC&A, Inc., October 16, 2002.

6

 In some cases a beverage can producer retains ownership of the UBC scrap but has the scrap processed by a

primary producer into new beverage can stock. The primary producer bills the scrap owner a per-ton tolling charge to

remelt and reprocess the scrap metal.

7

 This total probably includes plants dedicated to UBC remelting.

5-5 NUREG-1640

Table 5.2. Most of these data were compiled by Plunkert (2002), but are based on information

furnished to that author by The Aluminum Association.5

Used aluminum beverage cans (UBC) are typically processed in dedicated facilities that return

product to the can industry. This insures that the particular alloys used for cans remain

segregated and are processed without being commingled with general grades of scrap. This

material is not part of the general stream of old scrap that would be mixed with scrap cleared

from NRC-licensed facilities. On the other hand, a broad range of old aluminum scrap is

processed by the secondary aluminum recycling industry, primarily to produce foundry alloys.

Table 5.2 lists five types of facilities that recycle aluminum scrap. The first column of numbers

lists the total scrap consumption of each of these industries, based on published data. The next

column lists data on the consumption of old scrap. The quantities of old scrap consumed by the

four categories of secondary producers, other than secondary smelters, are estimated on the basis

of the reported data on the sums of old scrap and new scrap consumed by the facilities in these

four categories lumped together. It is assumed that the same ratio of old to new scrap applies to

each category individually. Furthermore, it is assumed that the fractional recovery of metal is

the same for old and new scrap. The non-UBC scrap consumed by secondary smelters was

calculated by subtracting the 88 kt of UBC scrap toll-treated6 for primary producers from the

listed amount of old scrap processed at these facilities. Finally, the amount of non-UBC old

scrap consumed by each of the four categories—other than secondary smelters—was estimated

by prorating the total amount of UBC scrap consumed by these four categories according to the

total amount of scrap consumed by each category.

5.2.3 Secondary Smelters

By far the largest consumers of non-UBC old scrap are secondary smelters producing foundry

alloys. It is therefore most likely that aluminum scrap cleared from an NRC-licensed facility and

destined for recycling would be consumed by one of these smelters. 

EPA (1995a) reported that the secondary aluminum industry operated about 68 plants and

employed about 3,600 workers.7

 Another source, Novelli 1997, states that the North American

industry involves 46 companies with 81 smelting operations. More recently, The Aluminum

Association (2002) reported that, in 2001, 75 plants produced secondary ingot. Total ingot

shipments from both primary and secondary sources were 5,886 million pounds (2,670 kt). As

listed in Table 5.2, secondary smelters consumed about 1,965 kt of scrap and recovered 1,450 kt
Recycling and Disposal of Aluminum Scrap Chapter 5

8

 “To facilitate handling, a significant proportion of the old aluminum scrap, and in some cases new scrap, is simply

melted to form sweated pig that must be processed further to make specification-grade ingot” (EPA 1995a). This is also

called remelt secondary ingot (RSI) by the aluminum industry. Because of its quality and pedigree, it is unlikely that

aluminum scrap from licensed facilities would follow this route.

9

 Since some members of the aluminum industry did not respond to USGS surveys, Plunkert (2002) scaled the sums

of the reported values to estimate the actual totals for the entire industry.

NUREG-1640 5-6

of metal in 2000. This scrap was from a mixture of old and new sources and included a small

amount (88 kt) of UBC scrap toll-treated for primary producers. About 70% of the metal

recovery in secondary smelters was from new scrap (Plunkert 2002, Table 4).

Table 5.2 U.S. industrial consumption and recovery from purchased aluminum scrap in 2000 (kt)

Consumption Recovery

Total Old scrapa New

 scrap

Total Old

scrapa,b

New

scrapb

Total non-UBC

Secondary smelters 1965c 593d 505e 1370 1450 440 1010

Integrated producers 1062c 496 99

1050

930 434 496

Independent mill fabricators 800 373 74 736 344 392

Foundries 95.6 44.6 8.9 85.8 40.1 45.7

Other consumers 14.6 6.8 1.4 14.6 6.8 7.8

Subtotal (excludes secondary smelters) 1972 920 183 1766 825 942

Total 3936c 1514 688 2420 3220 1270 1950

Adjusted totalf 4223c 1624 738 2590 3450c 1372c 2078c

Source: Plunkert 2002, unless otherwise noted

Notes: Includes imported scrap

Total metal content, scrap  93.3% Al

Most data rounded to no more than three significant figures, may not add to totals shown. a

 Old scrap includes sweated pig8

b

 Calculated from ratio of old scrap to new scrap consumed c

 Aluminum Association 2001

d

 Includes 88,000 t of UBC scrap toll-treated for primary producers e

 Figures in bold italics derived by present authors from published data

f

 Adjusted by multiplying “totals” by factor of 1.073 to estimate full industry coverage (4223 ÷ 3936 = 1.073)9

Figure 5.2 depicts a flow diagram for the processing of aluminum scrap at a typical secondary

smelter. Such a smelter most commonly uses an oil- or gas-fired reverberatory furnace of

40,000- to 220,000-lb (18-to 100-t) capacity (Viland 1990). The input material is usually

aluminum scrap and small amounts of additives such as silicon and zinc. Halide salts (such as

mixtures of NaCl, KCl, and NaF) are added to form a cover over the melt and reduce oxidation. 

For casting alloys, 2% to 13% silicon is added in the secondary smelting process to promote

casting alloy fluidity. The fumes that are generated during smelting are captured by the primary

exhaust hood and transported via a duct system to a baghouse. Occasionally, dirty aluminum

scrap undergoes pretreatment to remove iron, oil, and water. Pretreatment consists of crushing
Chapter 5 Recycling and Disposal of Aluminum Scrap

10 Saltcake is a general term for the residues of dross processing in rotary furnaces or by other means.

5-7 NUREG-1640

Figure 5.2 Processing and melting of aluminum scrap at typical secondary smelter

and/or drying (using an afterburner). The dust produced during pretreatment is collected in a

baghouse, either the same one used for the furnace or a similar facility. When the dust is

removed from the baghouse, it is tested for hazardous components to determine if it needs to be

handled as hazardous waste. About 99% of the dust produced during the recycling of aluminum

is considered nonhazardous. 

During each of the refining steps, the feed material separates into different product streams. 

Each of these products undergoes different treatment, use, and disposal.

Aluminum dross is not classified as a hazardous waste; therefore, it can be recycled, reprocessed,

or disposed of in a landfill. After dross is removed from the furnace and cooled, it is stored

outdoors in piles at the smelter until it is either re-used by the smelter or transported to a

processor for metal recovery. Dross processing may involve physical methods, such as hammer

mills and screens, or thermal methods, such as melting in rotary salt furnaces. After processing,

the dross residue is generally disposed of in solid waste landfills (Viland 1990). DOE (1999)

estimated that 2 billion pounds (~1.8 Mt) of dross and saltcake10 materials are landfilled

annually, after processing for aluminum recovery. Processes are being developed to reduce the

quantity of material destined for landfills by beneficially recovering oxide components. 

The aluminum alloys produced at the secondary smelters are typically cast into ingots that are

shipped to foundries for casting into end-user products. A significant quantity of product from

the secondary smelters is shipped as molten metal in insulated crucibles. An example of this

practice is the operations of one secondary smelter in Tennessee. Some of the metal is tapped
Recycling and Disposal of Aluminum Scrap Chapter 5

11 Insight into the U.S. share of North American production may be gained by noting that the United States

produced 72% of the primary aluminum made in North America in 1990, dropping to 61% in 2000, the balance being

made in Canada. Mexico, whose primary aluminum production equals about 1% of the North American total, is

classified as part of Latin America (The Aluminum Association 2001).

NUREG-1640 5-8

from the furnace into 30,000-lb (14-t) hot metal transporters. These cylindrical containers are

made with a steel shell and a castable lightweight refractory. The hot containers are manipulated

with an overhead crane which spans the tapping area and is used to load the containers onto

flatbed trucks for shipment. These containers can keep metal in the molten state for five to six

hours. Up to eight containers may be temporarily stored in the tapping area prior to shipment. 

Shipments are typically to plants in the immediate area. Approximately 500 million pounds

(~230 kt) per year of molten metal was shipped in crucibles on trucks in North America11

(Viland 1990). This may be compared to about 15 billion pounds (~68 Mt) per year of total

aluminum shipments in the United States alone in the late 1980's, presumably the time period of

the Viland data. Thus, the molten aluminum represents less than 3% of the total aluminum

shipments at that time.

According to Viland (1990), typical end-use markets for the castings include:

• Direct automotive . . . . . . . . . . . . . . . . 22%

• Automotive-related . . . . . . . . . . . . . . . 44%

• Small engine . . . . . . . . . . . . . . . . . . . . . . 8%

• Appliance . . . . . . . . . . . . . . . . . . . . . . . . 7%

• Other . . . . . . . . . . . . . . . . . . . . . . . . . . 19%

The Aluminum Association (1998) has estimated that the automotive industry consumes 65% to

70% of foundry ingot, which is consistent with the above estimates. 

5.2.4 Product Use

Finished aluminum products are used in many applications, including containers and packaging,

building and construction, transportation, electrical products, consumer durables, and machinery

and equipment. However, as noted above, most non-UBC scrap is used to produce various types

of casting alloys.

The total aluminum market and the market for aluminum ingot (both primary and secondary) in

2001 are summarized in Table 5.3. It can be seen from the table that nearly 70% of ingots (the

main product of secondary smelters) are shipped to transportation-related markets. Passenger

cars account for more than 60% of the total market for aluminum ingot. According to Accomet

Corporation (n/d) (a supplier of aluminum alloys to the automotive industry): “The average car

produced today contains over 250 pounds [> 110 kg] of aluminum in the form of various motor

mounts, pistons, heat exchangers, air conditioners, transmission housings, wheels, exteriors,

fenders, load floors and suspension components.” About 60% of this aluminum is from recycled

metal.
Chapter 5 Recycling and Disposal of Aluminum Scrap

5-9 NUREG-1640

Further details on end-use products for aluminum ingots are presented below (in millions of

pounds) (Aluminum Association 2002):

• Windows, doors, and screens . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23 (10 kt)

• Manufactured housing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 (1.4 kt)

• Bridge, street, and highway . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16 (7.3 kt)

• Trucks and buses . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 348 (158 kt)

• Passenger cars . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3,584 (1,626 kt)

• Trailers and semi-trailers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38 (17.2 kt)

• Air conditioners, freezers, refrigerators . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47 (21 kt)

• Portable appliances . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24 (11 kt)

• Cooking utensils . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21 (9.5 kt)

Table 5.3 Product net shipments by major market in 2001

Market Total aluminum Ingot

106

 lb kt Fraction 106 lb kt Fraction

Building & construction 2,895 1,313 13.5% 79 36 1.3%

Transportation 6,646 3,015 30.9% 4,052 1,838 68.8%

Consumer durables 1,444 655 6.7% 336 152 5.7%

Electrical 1,361 617 6.3% 185 84 3.1%

Machinery & equipment 1,299 589 6.0% 509 231 8.6%

Containers & packaging 4,851 2,200 22.6% -- 0 0.0%

Other 545 247 2.5% 255 116 4.3%

Domestic total 19,041 8,637 88.7% 5416 2,457 92.0%

Exports 2,435 1,105 11.3% 470 213 8.0%

Grand total 21,476 9,742 100.0% 5,886 2,670 100.0%

Source: Aluminum Association 2002

5.3 Mass Fractions and Partitioning Factors for Smelter Operations

For the purpose of the present analysis, the material entering a reverberatory furnace is

distributed into three process streams: metal product, dross, and offgas. The offgas consists of

gases and vapors as well as particulates. The particulates and the vapors that condense upon

cooling form dust, a portion of which is captured by the baghouse filters. The volatile fraction,

as well as the particulates that escape the baghouse, is released to the atmosphere. Any

impurities (e.g., radionuclides) in the scrap metal are likewise distributed among the metal,

dross, dust, and volatile effluent emissions.

5.3.1 Mass Fractions

The melting cycle for a typical reverberatory furnace consists of charging scrap into the forewell

of the furnace, blending and mixing alloying materials, adding fluxing salts, removing
Recycling and Disposal of Aluminum Scrap Chapter 5

12 Demagging is accomplished by injecting chlorine gas or another gaseous halogen into the melt.

13 Patricia Plunkert, U.S. Bureau of Mines, private communication with William C. Thurber, SC&A, Inc.,

September 20, 1995.

14 Robert H. Graham, plant manager, Wabash Alloys LLC, Dickson, TN, private communication with William C.

Thurber, SC&A, Inc., May 2, 1997.

15 Jim Bopp, Alchem Aluminum, private communication with Mary Anderson, SAIC, May 23, 1997.

16 Since these nominal values are cited solely to determine ratios of product streams, they would be the same in

metric units.

NUREG-1640 5-10

magnesium (“demagging”),12 removing gases, skimming off the dross, and pouring. A heel

consisting of 20% to 40% of the furnace capacity is generally left in the furnace to shorten the

melting cycle.13 Scrap is charged to the furnace, either with a front-end loader or a belt

conveyor, over a 16- to 18-hour period. Demagging and gas removal require two to four hours,

and tapping requires an additional three to four hours, resulting in a total cycle of about 24 hours.

Dross is a mixture of flux added to the melt, metal chlorides from demagging, and metal oxides. 

At the Dickson, TN, plant of Wabash Alloys LLC, a major producer of secondary aluminum, the

mass of the dross is about 15% of the mass of the metal charge.14 Another source estimated that

40% to 90% of the metal mass entering the furnace ends up in the metal product.15 If cleaner

scrap (new scrap) is used, the yield is close to 90%. It is expected that any aluminum scrap

cleared from an NRC-licensed facility would be of high quality and would be mixed with scrap

of similar quality, in which case yields would approach 90%. Viland (1990) noted that “For

every 1 million pounds16 of scrap processed, 760,000 pounds of secondary aluminum is

produced, and 240,000 pounds of dross residues, and 3,000 pounds of baghouse dusts are

generated.” Garbay and Chapuis (1991), who described French recycling practices, have stated

that a medium-sized plant melts 14 kt of aluminous waste and produces 11 kt of aluminum alloy,

3.3 kt of dross and 30 t of dust. Karvelas et al. (1991) quoted processing results from secondary

aluminum smelters in the United States in 1988. For each 1,100 tons16 of aluminum produced,

114 tons of dross, and 10 tons of baghouse dust were generated. The composition of the dross

was 12% – 20% Al, 20% – 25% NaCl, 20% – 25% KCl, 20% - 50% Al2O3, and 2% – 5% other

compounds. 

The mass fraction of dust cited by Viland (1990) is consistent with EPA 1995b, which cites a

value of 2.15 kilograms of dust per tonne of metal processed, with a standard deviation of 1.75

kg/t, for uncontrolled emissions from 10 reverberatory furnace source tests. Controlled

emissions employing a baghouse for these sources averaged 0.65 kg/t, with a standard deviation

of 0.15 kg/t. EPA 1995b notes: This factor may be lower if a coated baghouse is used. Under a

new rule promulgated by EPA (2000), particulate emissions from secondary aluminum smelters

will be limited to 0.4 lb per ton (0.2 kg/t) of material charged, which is lower than the measured

values cited in EPA 1995b. Existing smelters have until March 2003 to comply with this rule.
Chapter 5 Recycling and Disposal of Aluminum Scrap

5-11 NUREG-1640

Particulate emissions have also been measured from melt furnaces at Alcan Aluminum’s

recycling facility in Berea, KY (EPA 1990). Average particulate emissions were calculated to be

0.95 lb per ton of scrap (0.48 kg/t). This operation is typical of aluminum beverage can

recycling rather than of recycling old scrap for foundry alloys.

These mass fractions are summarized in Table 5.4.

Table 5.4 Comparison of mass fractions in secondary aluminum smelting

Source Metal Dust Dross

Viland 1990 0.76 3e-03 0.24

Garbay and Chapuis 1991 0.79 2e-03 0.24

Anigstein et al. 2001 0.94 0.15

Alchem Aluminum (Footnote 15) 0.4 – 0.9

EPA 1990 4.8e-04

EPA 1995b 2.15e-03 ± 1.75e-03

Karvelas et al. 1991 0.95 – 0.97 8.6e-03 to 8.8e-03 0.09 – 0.10 

It is apparent that some of the data in Table 5.4 are inconsistent with a materials balance. For

instance, Viland’s values (neglecting the small amount of dust) show the sum of the fractions to

be unity, which can only be true if dross is 100% aluminum or if there are other losses that are

not accounted for.

5.3.1.1 Adopted Values

The quantity of metallic aluminum produced from a given heat was calculated by subtracting the

amounts of chemically bound aluminum in the dross and in the dust (i.e., the amount of

aluminum in the form of Al2O3), from the amount of metal in the furnace charge. The fraction of

Al2O3 in dross was assigned a uniform distribution of 0.2 – 0.5, based on the values reported by

Karvelas et al. (1991) cited above. The mass fraction of aluminum in dust was assigned a fixed

value of 0.394, calculated from the relative concentrations of metallic elements in air samples

collected near furnaces at a secondary aluminum smelter (Kiefer et al. 1995), assuming that the

metals were in the form of oxides. The mass fraction of the metal product—an intermediate

result calculated separately during each realization, and thus not tabulated—is the ratio of mass

of molten metal to the mass of metal in the furnace charge.

The mass fraction of dross was assigned a triangular distribution, with a range of 0.09 – 0.24,

spanning the range of values listed in Table 5.4, and a most likely value of 0.15, based on the

practice at the Wabash Alloys plant in Dickson, TN. The dust fraction was assigned a normal

distribution with a mean of 2.15 × 10-3 and a standard deviation of 1.75 × 10-3, as reported in

EPA 1995b, but truncated at the lower end at 4.8 × 10-4, the value reported in EPA 1990 (see

Table 5.4). The latter is a reasonable minimum value for the present analysis since it is the

emission factor measured during the smelting of UBC scrap, which is relatively clean.
Recycling and Disposal of Aluminum Scrap Chapter 5

NUREG-1640 5-12

The fraction of dust released to the atmosphere is assigned a normal distribution, with a mean of

6.5 × 10-4 and a standard deviation of 1.5 × 10-4, based on the data reported in EPA 1995b. 

Although these emissions are expected to go down as a result of the limits mandated by EPA

(2000), these data, representing the most recent published measurements, were adopted for the

present analysis.

These data, together with additional parameters used to characterize the mass fractions in the

present analysis, are presented in Table B.7.

5.3.2 Partitioning Factors

This section presents a summary of the expected partitioning of impurities among the dross, the

metal, and the furnace emissions (particulate and gaseous) during the secondary smelting of

aluminum. A more detailed discussion is presented in Section J.3.1, from which the following

text is excerpted.

A major operation during the smelting of aluminum scrap involves the injection of chlorine gas

or other gaseous halogen into the melt to remove detrimental excess magnesium. Other

impurities in aluminum scrap may be transferred to the dross during this demagging operation,

depending on the relative thermodynamic stability of the respective chloride species. The

following reaction is assumed to be representative of transfer of selected metals from the melt to

the dross during demagging: 

M = metal dissolved in liquid aluminum

x = number of atoms of M in chloride salt

y = number of atoms of Cl in chloride salt

Values for the free energy of formation for this reaction at 1,000 K (a typical pouring

temperature for aluminum) were evaluated for various potential impurities in the scrap metal. 

Assuming that the above equation represents the governing chemistry, that equilibrium is

obtained, and that the dilute solutions behave as pure substances, it is expected that all the

elements whose chlorides have free energies of formation more negative than AlCl3 will be

transferred to the dross, and that those less negative than AlCl3 will tend to remain with the

aluminum (see Table J.23). Hydrogen should also be substantially but not totally removed from

the melt and released to the atmosphere. Hydrogen removal occurs by solution in the chlorine

rather than by HCl formation, which is thermodynamically unfavorable. Although

thermodynamic equilibria based on pure substances suggest that solute elements with standard

free energies of formation of the solute metal chlorides higher (less negative) than that of AlCl3

will remain in the melt, there is little information available on activity coefficients for the same

substances in dilute solutions. Thus, the thermochemical calculations provide only rough

guidelines as to the expected partitioning of trace impurities during melting.
Chapter 5 Recycling and Disposal of Aluminum Scrap

5-13 NUREG-1640

Many chlorides are volatile at low temperatures; this attribute may play a role in the partitioning

process. Addition of chlorine to the melt for demagging and hydrogen removal could result in

the formation of volatile chlorides. The possibility also exists that some species expected to be

transferred to the dross would also volatilize to some extent and either condense on the ducting

or be collected in the baghouse dust. 

Table 5.5 shows the ranges of partitioning factors adopted for each element represented by one

or more of the radionuclides addressed in the present analysis. Detailed data on the uncertainty

distributions of these partitioning factors are presented in Table B.7.

Table 5.5 Partitioning of contaminants in aluminum smelting (%)

Elements Metal

product Dross Baghousedust Volatile

H 0–20 0 0 80–100

C, Na, K, Ce 1–10 90–99 0 0

P, Cr, As, Se, Mo, Tc, Sn, Sb, Te, Ta, W, Os,

Ir, Tl, Pb, Bi, Po, Pa 50–100 0–25 0–25 0

S, Ru, Ag 100 0 0 0

Cl, Sc, Y, Cs, Pm, Sm, Eu, Gd, Tb, Tm, Ra 0 100 0 0

Ca, Sr 1–25 75–99 0 0

Mn, Fe, Co, Ni, Zn, Nb 80–98 1–10 1–10 0

Zr 0–100 0–100 0–100 0

Cd 90–99 0 1–10 0

I 0 50–100 0 0–50

Ba 0 90–99 1–10 0

Ac, Th, Np, Am, Cm, Bk, Cf, Es 1–50 50–99 0 0

U, Pu 1–50 50–89 0–10 0

5.4 Mixing of Cleared Scrap

The concentration of each radionuclide in cleared aluminum scrap would be reduced by mixing

with other materials, including scrap from other sources, prior to smelting. Further mixing

occurs during the disposal of smelter by-products. The mixing of cleared scrap and of the

products resulting from the smelting of the scrap are briefly discussed in this section. The type

of mixing factor used in each exposure scenario is listed in Table 5.6. A more detailed

discussion of mixing is presented in Section D.4.

5.4.1 Transport of Aluminum Scrap

Because of the small quantity of aluminum scrap that would be generated during the

dismantlement of a commercial nuclear power plant, it is assumed that all of this scrap would be

shipped off site as a single truck-load. It is further assumed that the cleared scrap in the truck

would be mixed with aluminum scrap from nonimpacted areas of the plant, or from other

sources. The mass of cleared scrap, which is represented by a uniform probability distribution
Recycling and Disposal of Aluminum Scrap Chapter 5

17 Gary Huddleston, environmental manager, Wabash Alloys LLC, private communication with Robert Anigstein,

SC&A, Inc., January, 2003.

NUREG-1640 5-14

with a range of 1.2 to 2.0 t, is mixed into a 20-t load of scrap. The resulting mixing factors have

a range of 0.06 – 0.1.

5.4.2 Processing Aluminum Scrap at Scrap Yard

The aluminum scrap would be processed at a facility specializing in nonferrous metals. Such

scrap processing facilities are discussed in Chapter 4 and analyzed in greater detail in Section

D.3.1, which presents a probability distribution of the throughput of the nonferrous metal scrap

processors. The mean throughput is about 11 kt/y, yielding an average mixing factor of cleared

aluminum scrap, as reflected by the mean value of 10,000 Monte Carlo realizations, of about

2.3 × 10-4. 

5.4.3 Secondary Smelter Operations

5.4.3.1 Annual-Average Mixing Factors

As is discussed in the next section, the cleared scrap would most likely be processed and charged

to the reverberatory furnace in a single batch. However, for the purpose of assessing the doses

of individuals exposed to a continuous stream of smelter products over the course of a year, it is

useful to calculate annual-average mixing factors. A longer discussion of this concept is

presented in Section D.1. The annual-average mixing factor for products of the secondary

smelter is calculated as the ratio of the mass of cleared scrap to the annual production capacity of

the smelter. The capacity is sampled from the distribution of aluminum smelter capacities

described in Section D.4.2.1, yielding an average mixing factor (the mean value of 10,000 Monte

Carlo realizations) of about 1.8 × 10-5.

5.4.3.2 Single-Heat Mixing Factors

The two tonnes (or less) of aluminum scrap that would be cleared from an NRC-licensed facility

is much less than the capacity of a reverberatory furnace at a secondary aluminum smelter. As

confirmed by a staff member of Wabash Alloys LLC, it is most likely that all of the cleared scrap

would charged to the furnace in a single heat.17 Consequently, the mixing factor for all of the

product use scenarios was calculated as the ratio of the scrap cleared during the dismantlement

of a single nuclear power plant to the capacity of a reverberatory furnace, resulting in an average

mixing factor (the mean value of 10,000 Monte Carlo realizations) of about 2.0%. Additional

details are presented in Section D.4.2.2.
Chapter 5 Recycling and Disposal of Aluminum Scrap

5-15 NUREG-1640

5.5 Radionuclide Concentrations in Various Media

The smelting process redistributes any impurities (such as radionuclides) in the scrap among the

various furnace products. This partitioning is dependent on the chemical element in question

and applies to all isotopes of that element. 

The annual-average radionuclide concentrations in refined aluminum and in the by-products of

the smelting/melting of aluminum scrap in a reverberatory furnace, as well as the annual activity

of each nuclide released to the atmosphere, employ the equations listed in Section 3.5.1. The

parameters specific to aluminum are based on the available information on the secondary

aluminum industry presented in Section 5.2. The values adopted for the present analysis are

listed in Tables B.6 and B.7. 

The radionuclide concentrations in the metal product, based on the single-heat mixing factors

discussed in Section 5.4.3.2, were calculated as follows:

Sip = concentration of nuclide i in metal produced from maximum single heat

Cio = initial concentration of nuclide i in cleared scrap

fip = partition factor of nuclide i in metal product (see Table 5.5)

fmc = single-heat mixing factor

=

mAl = mass of aluminum scrap cleared from a single nuclear power plant

Mf = capacity of reverberatory furnace (details in Appendix D) 

fp = mass fraction of metal product (see Section 5.3.1.1)

The mean and the 5th, 50th, and 95th percentile radionuclide concentrations in the products of

the secondary smelter, as well as the annual activities released to the atmosphere, are listed in

Appendix K. 

5.6 Aluminum Recycling and Disposal Scenarios

The 21 exposure scenarios included in the aluminum analysis, along with the environmental

transport pathways included in each scenario, are listed in Table 5.6. The basis of each scenario

is listed in the column headed “CA” (corresponding analysis). Each of the 14 scenarios

indicated by the notation “Fe” is based on the corresponding scenario in the steel analysis, which

has the same or a similar title. One of these scenarios, indicated by “Fe-mod,” involves a

significant modification of the corresponding steel scenario, as discussed later in this section. 
Recycling and Disposal of Aluminum Scrap Chapter 5

18 All parameter values that are specific to the aluminum exposure scenarios are listed in Table B.10. All other

parameters have the values listed for the corresponding steel scenarios in Table B.8 or the similar copper scenarios in

Table B.9.

NUREG-1640 5-16

Six more scenarios, noted “Cu,” are based on corresponding copper scenarios. (Aluminum

scenarios involving dross correspond to steel or copper scenarios involving slag.) In addition,

there is one new product use scenario: a person using a cooking utensil made from recycled

aluminum. Only those aspects of the analysis that are new or significantly different than the

corresponding steel or copper analyses are discussed in this section.18

5.6.1 Inhalation of Aluminum Dusts

There are no specific OSHA limits on the inhalation of aluminum dusts. Such dusts therefore

come under the general category of nuisance dusts. The permissible exposure limit (PEL) for

such dusts is 5 mg/m3

 of respirable particles. The mass loading of dust from aluminum

processing, handling, and disposal was modeled in the same manner as for steel slag, described

in Section 3.7.1.2. These dust concentrations are used in all the handling, processing, and

disposal scenarios which include the inhalation pathway, as indicated in Table 5.6. The dust

concentrations in the dross and dust transportation scenarios are the same as in the corresponding

scenarios in the steel and copper analyses.

5.6.2 Handling Dross at Secondary Smelter

It is assumed that an average of about 500 t of dross is stored at a secondary smelter. It is more

realistic to model this as a mound, with a worker engaged in activities in its vicinity, rather than

as an essentially infinite plane, as was done in the corresponding slag handling scenario in the

steel analysis. The dross handling scenario thus corresponds more closely to the scenario that

models the processing of steel slag for use in road construction.

5.6.3 Use of Aluminum Cooking Ware

A person cooking food in an aluminum pot would be exposed to direct penetrating radiation

from any residual radionuclide concentrations in the metal, in addition to eating food which may

be contaminated with radionuclides that have leached from the pan.

5.6.3.1 External Exposure

The duration of external exposure was modeled as a lognormal distribution, with a mean of ~52

min/d, an arithmetic standard deviation of ~53 min/d, and truncated at the lower end at one

minute per day. These values are based on the time spent on food preparation in a given 24-hour

period by all survey respondents, reported in EPA 1997, Table 15-88. Since these include

respondents who spent as little as one minute per day on food preparation, it is reasonable to

assume that these are daily averages that would apply to an entire year.
Chapter 5 Recycling and Disposal of Aluminum Scrap

5-17 NUREG-1640

Table 5.6 Scenario and exposure pathway matrix

Scenario abbreviation Scenario title MFa CAb Pathwaysc

Extd Inh Ing

Handling and Processing

Scrap yard Processing aluminum scrap at scrap yard SD Cu 30 ! !

Handling metal product Handling metal product at secondary smelter AA Fe 33 ! !

Handling dross Handling dross at secondary smelter AA Fe-mod 31 ! !

Baghouse maintenance Baghouse maintenance at secondary smelter AA Fe 32

Atmospheric Release

Airborne emissions Emission of airborne effluents from smelter AA Fe F2 ! !

Transportation

Scrap truck–driver Truck driver hauling cleared aluminum scrap ST Cu 35

Metal product–driver Truck driver hauling metal product from smelter AA Fe 38

Dross truck–driver Truck driver hauling dross from smelter AA Cu 36 ! !

Dust truck–driver Truck driver hauling dust from smelter AA Cu 37 ! !

Product Use

Exposure to large mass Exposure to large metal mass SH Fe 33

Exposure to small mass Exposure to small metal mass SH Fe 34

Driver–engine block Driver of taxi with aluminum engine block SH Fe 39

Aluminum cookware Use of aluminum cooking ware SH New 40 !

Landfill Disposal

Scrap disposal–industrial Handling aluminum scrap at industrial landfill IL Fe F1

Scrap disposal–municipal Handling aluminum scrap at municipal landfill ML Fe F1

Dross disposal–industrial Handling dross at industrial landfill IL Fe F1 ! !

Dross disposal–municipal Handling dross at municipal landfill ML Fe F1 ! !

Groundwater Contaminated by Leachate from Landfills

Leachate–industrial–scrap Leachate from industrial landfill–scrap IL Fe !

Leachate–municipal–scrap Leachate from municipal landfill–scrap ML Fe !

Leachate–industrial–dross Leachate from industrial landfill–dross IL Cu !

Leachate–municipal–dross Leachate from municipal landfill–dross ML Cu ! a MF = mixing factor: AA = annual average, IL = industrial landfill, ML = municipal landfill, SD = scrap dealer, SH = single heat,

ST = scrap truck (see text—details in Appendix D)

b CA = corresponding analysis: Fe = steel, Cu = copper

c Exposure pathways: Ext = external, Inh = inhalation, Ing = ingestion of food, water, or soil; inadvertent ingestion

d External exposure dose factors:

30 Scrap pile

31 Dross pile

32 Baghouse

33 Large metal object

34 Small metal object

35 Scrap truck

36 Dross truck

37 Dust truck

38 Truck loaded with metal product

39 Auto—aluminum engine block

40 Cooking pot

F1 Soil contaminated to an infinite depth (Eckerman and Ryman 1993)

F2 Contaminated ground surface (Eckerman and Ryman 1993)
Recycling and Disposal of Aluminum Scrap Chapter 5

19 An exact expression for this quantity is presented in Section 3.5.2.

NUREG-1640 5-18

5.1

5.6.3.2 Ingestion Exposure

Blumenthal (1990) wrote that “. . . a person using uncoated aluminum pans for all cooking and

food storage every day would take in an estimated 3.5 milligrams of aluminum daily.” This was

the only quantitative estimate of total intake of aluminum from kitchen utensils that was found in

the literature, and was adopted as the fixed value for the present analysis. Again, since this is a

daily average, it is assumed that the exposure would occur each day of the year. The dose from

the ingestion pathway is expressed as follows:

Dic = dose from ingestion of radionuclide i in cooking ware during assessment period

(:Sv)

Cip = undecayed specific activity of radionuclide i in metal product19 (Bq/g)

Fig = dose conversion factor for ingestion of radionuclide i (:Sv/Bq)

mAl = intake of aluminum from cooking ware

= 0.0035 g/d

tys = exposure duration (d)

ts = time from clearance of material to the time the scenario begins (d)

i = radioactive decay rate of nuclide i (d-1)

ta = period of assessment

Equation 5.1 expresses the assumption that any radionuclides that partitioned to the aluminum

during smelting would leach into the food at the same relative rate as the aluminum. Therefore,

the daily intake of a given nuclide in the aluminum pot is the product of the daily intake of

aluminum and the specific activity of the nuclide in the aluminum.

5.6.4 Scenario Timing

This section presents the basic assumptions used in defining the time periods for each of the

aluminum exposure scenarios. 

5.6.4.1 Scrap Transport and Handling

• All cleared scrap is assumed to be initially transported to a scrap dealer. Transportation

takes place two to six days after clearance.
Chapter 5 Recycling and Disposal of Aluminum Scrap

20 Molten metal is transported immediately after being poured from the furnace. However, the scenario modeled in

the present analysis is the transport of cast ingots, which would typically take place a few days after production. As

discussed in Section 5.2.3, molten aluminum shipments are a small fraction of total aluminum production.

21 As an example, the New York City Taxi and Limousine Commission requires medallion taxis (cabs allowed to

pick up passengers on the street) to be replaced every three years.

5-19 NUREG-1640

• Disposal in a landfill occurs three to 13 days after clearance.

• The scrap is processed and remains at the scrap dealer for a period of one to 30 days after it

arrives.

5.6.4.2 Refining and Processing

• The operations at the secondary smelter take place one to 15 days after the scrap is shipped

from the scrap dealer.

• Atmospheric releases from the furnace occur at the time the scrap is smelted.

• Dross and dust are produced at the time the scrap is smelted.

5.6.4.3 Transportation of Smelter Products

• The metal is assumed to be transported three to 30 days after it is produced.20

• Dross and dust from the reverberatory furnace are collected periodically and sent to a third

party for metal recovery. Transportation is assumed to take place 30 to 60 days after the dust

and dross are generated.

5.6.4.4 Use of Aluminum Products

• Manufactured items are put into use 10 to 60 days after the aluminum is shipped from the

secondary smelter.

• Generic aluminum products are assumed to have a useful life of 30 years. There are two

specific aluminum products in the present analysis: an aluminum engine block and an

aluminum cooking pot. The engine block is assumed to be in a taxicab which is driven by its

owner an average of about 2,500 hours per year. In addition, it may be leased to other

drivers when the owner is off duty. Due to heavy use, the engine is assumed to have a

service life of three years.21 An aluminum pot is assumed to have a service life of 20 years.
Recycling and Disposal of Aluminum Scrap Chapter 5

22 As discussed in Chapter 1, the group which receives the highest mean normalized EDE from a given

radionuclide is defined as the EDE-critical group for that nuclide.

NUREG-1640 5-20

Figure 5.3 Scenarios giving rise to EDE-critical groups for aluminum

5.7 Dose Assessments of Recycling and Disposal of Aluminum Scrap

As discussed in previous sections of this chapter, the radiological assessment of the clearance of

aluminum scrap from NRC-licensed nuclear facilities evaluates the radiation exposures of

individual members of various groups to each of 115 radionuclides and their progenies in 21

exposure scenarios. 

5.7.1 Calculation of Effective Dose Equivalents (EDEs)

The groups described by four scenarios receive the highest mean normalized EDEs from one

year of exposure to cleared aluminum scrap from all 115 nuclides, one scenario constituting the

EDE-critical group for 78 nuclides.22 Table 5.7 lists the mean and the 5th, 50th, and 95th

percentile mass-based normalized EDEs from each radionuclide to its respective critical group,

while Table 5.8 lists the corresponding surficial EDEs. Figure 5.3 lists the scenarios describing

the EDE-critical groups and displays the number of radionuclides for which each scenario

constitutes the critical group. The mean and the 5th, 50th, 90th, and 95th percentile normalized

EDEs from all 115 nuclides for all 21 scenarios are tabulated in Appendix H-1.

The scrap yard worker scenario gives rise to the critical group for the largest number of

radionuclides. Since this scenario includes all three principal environmental pathways—external

exposure, inhalation, and inadvertent ingestion—it leads to potential doses from nuclides which

are strong photon emitters, as well as from those that deliver their primary dose via alpha or beta

emission.

The drivers of taxicabs with aluminum engine blocks constitute the critical group for a number

of nuclides that partition strongly to the metal during smelting and are strong external emitters. 

Several factors account for this being the critical group for 24 radionuclides. First is the average
Chapter 5 Recycling and Disposal of Aluminum Scrap

5-21 NUREG-1640

Figure 5.4 Scenarios giving rise to effective dose-critical groups for aluminum

mixing factor of 2.0%, as cited in Section 5.4.3.2. Second is the long exposure duration—the

driver spends an average of about nine hours per day, six days a week in his taxi. (A detailed

discussion of the exposure duration in this scenario is presented in Section 3.7.5.5.)

5.7.2 Calculation of Effective Doses

The groups described by five scenarios receive the highest mean normalized effective doses from

one year of exposure to cleared aluminum scrap from all 115 nuclides, the scrap yard workers

constituting the critical group for 77 nuclides. Table 5.9 lists the mean and the 5th, 50th, and

95th percentile mass-based normalized effective doses from each radionuclide to its respective

critical group, while Table 5.10 lists the corresponding surficial effective doses. Figure 5.4 lists

the scenarios describing the effective dose-critical groups and displays the number of

radionuclides for which each scenario constitutes the critical group. The mean and the 5th, 50th,

90th, and 95th percentile normalized effective doses from all 115 nuclides for all 21 scenarios

are tabulated in Appendix H-2.

The factors leading to the highest effective doses in these scenarios are similar to those giving

rise to the EDE-critical groups discussed in Section 5.7.1.
Recycling and Disposal of Aluminum Scrap Chapter 5

NUREG-1640 5-22

Table 5.7 Normalized mass-based effective dose equivalents to critical groups for aluminum Radionuclide

:Sv/y per Bq/g mrem/y per pCi/g

Scenario

Mean

Percentilea

Mean

Percentilea

5th 50th 95th 5th 50th 95th

H-3 2.8e-06 0.0e+00 2.6e-09 1.0e-05 1.0e-08 0.0e+00 9.5e-12 3.8e-08 Leachate-industrial-scrap

C-14 4.5e-06 0.0e+00 0.0e+00 8.5e-06 1.7e-08 0.0e+00 0.0e+00 3.1e-08 Leachate-industrial-scrap

Na-22 2.9e-02 7.2e-03 1.8e-02 8.6e-02 1.1e-04 2.7e-05 6.8e-05 3.2e-04 Scrap yard

P-32 2.1e-05 3.8e-06 1.3e-05 6.8e-05 7.9e-08 1.4e-08 4.8e-08 2.5e-07 Scrap yard

S-35 8.2e-07 2.0e-07 5.2e-07 2.5e-06 3.1e-09 7.5e-10 1.9e-09 9.2e-09 Scrap yard

Cl-36 5.9e-05 0.0e+00 0.0e+00 2.4e-04 2.2e-07 0.0e+00 0.0e+00 8.9e-07 Leachate-industrial-scrap

K-40 2.2e-03 5.5e-04 1.4e-03 6.6e-03 8.2e-06 2.0e-06 5.2e-06 2.4e-05 Scrap yard

Ca-41 2.9e-05 0.0e+00 0.0e+00 1.2e-04 1.1e-07 0.0e+00 0.0e+00 4.6e-07 Leachate-industrial-scrap

Ca-45 3.8e-06 8.0e-07 2.4e-06 1.2e-05 1.4e-08 3.0e-09 8.9e-09 4.5e-08 Scrap yard

Sc-46 2.3e-02 5.8e-03 1.5e-02 7.1e-02 8.7e-05 2.1e-05 5.5e-05 2.6e-04 Scrap yard

Cr-51 2.4e-04 5.4e-05 1.5e-04 7.4e-04 8.8e-07 2.0e-07 5.5e-07 2.7e-06 Scrap yard

Mn-53 6.7e-07 4.4e-07 6.1e-07 1.2e-06 2.5e-09 1.6e-09 2.3e-09 4.6e-09 Aluminum cookware

Mn-54 5.6e-02 3.1e-02 5.1e-02 1.0e-01 2.1e-04 1.2e-04 1.9e-04 3.8e-04 Driver-engine block

Fe-55 3.1e-06 2.1e-06 2.9e-06 5.8e-06 1.2e-08 7.6e-09 1.1e-08 2.1e-08 Aluminum cookware

Fe-59 1.2e-02 2.9e-03 7.7e-03 3.7e-02 4.5e-05 1.1e-05 2.9e-05 1.4e-04 Scrap yard

Co-56 4.8e-02 1.6e-02 4.0e-02 1.0e-01 1.8e-04 6.1e-05 1.5e-04 3.8e-04 Driver-engine block

Co-57 7.2e-03 3.9e-03 6.5e-03 1.3e-02 2.7e-05 1.4e-05 2.4e-05 4.9e-05 Driver-engine block

Co-58 1.3e-02 3.9e-03 1.0e-02 2.8e-02 4.6e-05 1.5e-05 3.8e-05 1.0e-04 Driver-engine block

Co-60 2.6e-01 1.5e-01 2.4e-01 4.7e-01 9.6e-04 5.5e-04 8.7e-04 1.7e-03 Driver-engine block

Ni-59 2.2e-06 1.3e-06 2.0e-06 4.0e-06 8.1e-09 4.7e-09 7.4e-09 1.5e-08 Driver-engine block

Ni-63 3.5e-06 2.3e-06 3.2e-06 6.6e-06 1.3e-08 8.7e-09 1.2e-08 2.4e-08 Aluminum cookware

Zn-65 3.1e-02 1.7e-02 2.8e-02 5.8e-02 1.2e-04 6.2e-05 1.0e-04 2.1e-04 Driver-engine block

As-73 1.8e-05 6.0e-06 1.5e-05 3.8e-05 6.5e-08 2.2e-08 5.5e-08 1.4e-07 Driver-engine block

Se-75 1.0e-02 4.4e-03 9.0e-03 2.0e-02 3.8e-05 1.6e-05 3.3e-05 7.4e-05 Driver-engine block

Sr-85 5.1e-03 1.3e-03 3.3e-03 1.6e-02 1.9e-05 4.6e-06 1.2e-05 5.8e-05 Scrap yard

Sr-89 2.9e-05 7.6e-06 1.9e-05 8.9e-05 1.1e-07 2.8e-08 6.9e-08 3.3e-07 Scrap yard

Sr-90 2.6e-04 6.3e-05 1.6e-04 7.9e-04 9.5e-07 2.3e-07 6.0e-07 2.9e-06 Scrap yard

Y-91 7.9e-05 2.1e-05 5.0e-05 2.4e-04 2.9e-07 7.7e-08 1.9e-07 8.8e-07 Scrap yard

Zr-93 2.1e-05 5.2e-06 1.3e-05 6.3e-05 7.6e-08 1.9e-08 4.8e-08 2.3e-07 Scrap yard

Zr-95 1.1e-02 2.7e-03 6.8e-03 3.2e-02 4.0e-05 9.8e-06 2.5e-05 1.2e-04 Scrap yard

Nb-93m 7.3e-06 1.9e-06 4.6e-06 2.2e-05 2.7e-08 6.9e-09 1.7e-08 8.2e-08 Scrap yard

Nb-94 2.0e-01 1.1e-01 1.8e-01 3.6e-01 7.3e-04 4.3e-04 6.7e-04 1.3e-03 Driver-engine block

Nb-95 7.1e-03 1.7e-03 4.5e-03 2.2e-02 2.6e-05 6.1e-06 1.6e-05 8.0e-05 Scrap yard

Mo-93 9.0e-06 5.6e-06 8.2e-06 1.7e-05 3.3e-08 2.1e-08 3.0e-08 6.2e-08 Aluminum cookware

Tc-97 3.0e-05 0.0e+00 0.0e+00 1.3e-04 1.1e-07 0.0e+00 0.0e+00 4.7e-07 Leachate-industrial-scrap

Tc-97m 4.6e-06 1.2e-06 2.9e-06 1.4e-05 1.7e-08 4.6e-09 1.1e-08 5.0e-08 Scrap yard

Tc-99 2.5e-04 0.0e+00 0.0e+00 1.1e-03 9.4e-07 0.0e+00 0.0e+00 4.0e-06 Leachate-industrial-scrap

Ru-103 4.5e-03 1.1e-03 2.9e-03 1.4e-02 1.7e-05 4.0e-06 1.1e-05 5.1e-05 Scrap yard

Ru-106 1.9e-02 1.1e-02 1.8e-02 3.5e-02 7.2e-05 4.0e-05 6.5e-05 1.3e-04 Driver-engine block

a

 5th percentile to 95th percentile = 90% confidence interval
Chapter 5 Recycling and Disposal of Aluminum Scrap

Table 5.7 Normalized mass-based effective dose equivalents to critical groups for aluminum Radionuclide

:Sv/y per Bq/g mrem/y per pCi/g

Scenario

Mean

Percentilea

Mean

Percentilea

5th 50th 95th 5th 50th 95th

5-23 NUREG-1640

Ag-108m 2.4e-01 1.4e-01 2.2e-01 4.3e-01 8.9e-04 5.2e-04 8.1e-04 1.6e-03 Driver-engine block

Ag-110m 1.7e-01 9.4e-02 1.6e-01 3.2e-01 6.5e-04 3.5e-04 5.8e-04 1.2e-03 Driver-engine block

Cd-109 2.0e-04 1.1e-04 1.8e-04 3.7e-04 7.5e-07 4.2e-07 6.7e-07 1.4e-06 Driver-engine block

Sn-113 6.6e-03 2.8e-03 5.8e-03 1.3e-02 2.5e-05 1.0e-05 2.1e-05 4.8e-05 Driver-engine block

Sb-124 2.0e-02 4.9e-03 1.3e-02 6.1e-02 7.5e-05 1.8e-05 4.7e-05 2.3e-04 Scrap yard

Sb-125 4.0e-02 2.3e-02 3.7e-02 7.3e-02 1.5e-04 8.3e-05 1.4e-04 2.7e-04 Driver-engine block

Te-123m 3.5e-03 1.5e-03 3.1e-03 6.8e-03 1.3e-05 5.6e-06 1.1e-05 2.5e-05 Driver-engine block

Te-127m 1.3e-04 5.2e-05 1.1e-04 2.5e-04 4.7e-07 1.9e-07 4.1e-07 9.3e-07 Driver-engine block

I-125 4.8e-05 1.1e-05 3.0e-05 1.5e-04 1.8e-07 4.1e-08 1.1e-07 5.4e-07 Scrap yard

I-129 1.2e-02 0.0e+00 0.0e+00 4.4e-02 4.5e-05 0.0e+00 0.0e+00 1.6e-04 Leachate-industrial-scrap

I-131 1.2e-03 1.1e-04 6.0e-04 4.1e-03 4.5e-06 4.1e-07 2.2e-06 1.5e-05 Scrap yard

Cs-134 2.0e-02 5.0e-03 1.3e-02 6.1e-02 7.5e-05 1.9e-05 4.8e-05 2.2e-04 Scrap yard

Cs-135 6.8e-06 9.8e-07 4.2e-06 2.2e-05 2.5e-08 3.6e-09 1.6e-08 8.1e-08 Scrap yard

Cs-137 7.4e-03 1.8e-03 4.7e-03 2.2e-02 2.8e-05 6.8e-06 1.8e-05 8.2e-05 Scrap yard

Ba-133 4.2e-03 1.0e-03 2.7e-03 1.3e-02 1.6e-05 3.9e-06 9.9e-06 4.6e-05 Scrap yard

Ce-139 1.2e-03 2.9e-04 7.5e-04 3.6e-03 4.4e-06 1.1e-06 2.8e-06 1.3e-05 Scrap yard

Ce-141 4.4e-04 1.0e-04 2.8e-04 1.3e-03 1.6e-06 3.8e-07 1.0e-06 5.0e-06 Scrap yard

Ce-144 7.3e-04 1.9e-04 4.6e-04 2.2e-03 2.7e-06 7.1e-07 1.7e-06 8.1e-06 Scrap yard

Pm-147 9.9e-06 2.5e-06 6.2e-06 3.0e-05 3.6e-08 9.4e-09 2.3e-08 1.1e-07 Scrap yard

Sm-151 7.2e-06 1.8e-06 4.5e-06 2.2e-05 2.7e-08 6.8e-09 1.7e-08 8.2e-08 Scrap yard

Eu-152 1.5e-02 3.8e-03 9.7e-03 4.6e-02 5.7e-05 1.4e-05 3.6e-05 1.7e-04 Scrap yard

Eu-154 1.5e-02 3.7e-03 9.5e-03 4.4e-02 5.5e-05 1.4e-05 3.5e-05 1.6e-04 Scrap yard

Eu-155 3.4e-04 8.6e-05 2.2e-04 1.0e-03 1.3e-06 3.2e-07 8.1e-07 3.8e-06 Scrap yard

Gd-153 4.3e-04 1.1e-04 2.7e-04 1.3e-03 1.6e-06 3.9e-07 1.0e-06 4.7e-06 Scrap yard

Tb-160 1.2e-02 3.1e-03 7.9e-03 3.8e-02 4.6e-05 1.1e-05 2.9e-05 1.4e-04 Scrap yard

Tm-170 3.1e-05 8.5e-06 2.0e-05 9.1e-05 1.1e-07 3.1e-08 7.3e-08 3.4e-07 Scrap yard

Tm-171 4.1e-06 1.2e-06 2.6e-06 1.2e-05 1.5e-08 4.3e-09 9.7e-09 4.5e-08 Scrap yard

Ta-182 2.7e-02 1.1e-02 2.4e-02 5.3e-02 1.0e-04 4.2e-05 8.7e-05 2.0e-04 Driver-engine block

W-181 3.1e-04 1.3e-04 2.7e-04 6.0e-04 1.1e-06 4.9e-07 1.0e-06 2.2e-06 Driver-engine block

W-185 2.1e-06 4.9e-07 1.3e-06 6.5e-06 7.8e-09 1.8e-09 4.9e-09 2.4e-08 Scrap yard

Os-185 1.2e-02 4.5e-03 1.0e-02 2.4e-02 4.4e-05 1.7e-05 3.8e-05 9.0e-05 Driver-engine block

Ir-192 1.1e-02 3.4e-03 8.9e-03 2.4e-02 3.9e-05 1.2e-05 3.3e-05 8.8e-05 Driver-engine block

Tl-204 1.0e-04 5.6e-05 9.1e-05 1.8e-04 3.7e-07 2.1e-07 3.4e-07 6.8e-07 Driver-engine block

Pb-210 3.7e-02 2.4e-02 3.4e-02 6.9e-02 1.4e-04 8.7e-05 1.3e-04 2.5e-04 Aluminum cookware

Bi-207 1.6e-01 8.8e-02 1.4e-01 2.9e-01 5.8e-04 3.3e-04 5.3e-04 1.1e-03 Driver-engine block

Po-210 3.1e-03 1.8e-03 2.8e-03 5.8e-03 1.2e-05 6.5e-06 1.0e-05 2.2e-05 Aluminum cookware

Ra-226 2.6e-02 6.9e-03 1.7e-02 7.8e-02 9.7e-05 2.5e-05 6.2e-05 2.9e-04 Scrap yard

Ra-228 1.5e-02 4.1e-03 9.7e-03 4.5e-02 5.6e-05 1.5e-05 3.6e-05 1.7e-04 Scrap yard

a

 5th percentile to 95th percentile = 90% confidence interval
Recycling and Disposal of Aluminum Scrap Chapter 5

Table 5.7 Normalized mass-based effective dose equivalents to critical groups for aluminum Radionuclide

:Sv/y per Bq/g mrem/y per pCi/g

Scenario

Mean

Percentilea

Mean

Percentilea

5th 50th 95th 5th 50th 95th

NUREG-1640 5-24

Ac-227 3.2e-01 8.1e-02 2.0e-01 9.7e-01 1.2e-03 3.0e-04 7.4e-04 3.6e-03 Scrap yard

Th-228 7.7e-02 2.1e-02 4.9e-02 2.4e-01 2.8e-04 7.8e-05 1.8e-04 8.7e-04 Scrap yard

Th-229 5.1e-01 1.3e-01 3.2e-01 1.5e+00 1.9e-03 4.7e-04 1.2e-03 5.7e-03 Scrap yard

Th-230 7.6e-02 1.9e-02 4.7e-02 2.3e-01 2.8e-04 7.0e-05 1.8e-04 8.5e-04 Scrap yard

Th-232 3.8e-01 9.5e-02 2.4e-01 1.2e+00 1.4e-03 3.5e-04 8.8e-04 4.3e-03 Scrap yard

Pa-231 3.1e-01 7.7e-02 1.9e-01 9.3e-01 1.1e-03 2.9e-04 7.1e-04 3.4e-03 Scrap yard

U-232 1.5e-01 3.9e-02 9.7e-02 4.7e-01 5.7e-04 1.4e-04 3.6e-04 1.7e-03 Scrap yard

U-233 3.1e-02 7.9e-03 2.0e-02 9.6e-02 1.2e-04 2.9e-05 7.3e-05 3.5e-04 Scrap yard

U-234 3.1e-02 7.7e-03 1.9e-02 9.4e-02 1.1e-04 2.9e-05 7.1e-05 3.5e-04 Scrap yard

U-235 3.0e-02 7.8e-03 1.9e-02 9.3e-02 1.1e-04 2.9e-05 7.0e-05 3.4e-04 Scrap yard

U-236 2.9e-02 7.3e-03 1.8e-02 8.9e-02 1.1e-04 2.7e-05 6.8e-05 3.3e-04 Scrap yard

U-238 2.8e-02 7.0e-03 1.8e-02 8.5e-02 1.0e-04 2.6e-05 6.5e-05 3.1e-04 Scrap yard

Np-237 1.3e-01 3.3e-02 8.2e-02 4.0e-01 4.8e-04 1.2e-04 3.0e-04 1.5e-03 Scrap yard

Pu-236 3.4e-02 8.6e-03 2.1e-02 1.0e-01 1.3e-04 3.2e-05 7.9e-05 3.8e-04 Scrap yard

Pu-238 9.3e-02 2.4e-02 5.8e-02 2.8e-01 3.4e-04 8.7e-05 2.2e-04 1.0e-03 Scrap yard

Pu-239 1.0e-01 2.6e-02 6.4e-02 3.1e-01 3.8e-04 9.5e-05 2.4e-04 1.1e-03 Scrap yard

Pu-240 1.0e-01 2.6e-02 6.4e-02 3.1e-01 3.8e-04 9.5e-05 2.4e-04 1.1e-03 Scrap yard

Pu-241 2.0e-03 5.0e-04 1.2e-03 6.0e-03 7.3e-06 1.8e-06 4.5e-06 2.2e-05 Scrap yard

Pu-242 9.7e-02 2.5e-02 6.1e-02 3.0e-01 3.6e-04 9.1e-05 2.3e-04 1.1e-03 Scrap yard

Pu-244 1.0e-01 2.6e-02 6.3e-02 3.1e-01 3.7e-04 9.5e-05 2.3e-04 1.1e-03 Scrap yard

Am-241 1.1e-01 2.7e-02 6.6e-02 3.2e-01 3.9e-04 9.9e-05 2.4e-04 1.2e-03 Scrap yard

Am-242m 1.0e-01 2.6e-02 6.5e-02 3.2e-01 3.9e-04 9.8e-05 2.4e-04 1.2e-03 Scrap yard

Am-243 1.1e-01 2.7e-02 6.7e-02 3.2e-01 3.9e-04 1.0e-04 2.5e-04 1.2e-03 Scrap yard

Cm-242 3.8e-03 9.5e-04 2.4e-03 1.2e-02 1.4e-05 3.5e-06 8.8e-06 4.3e-05 Scrap yard

Cm-243 7.4e-02 1.9e-02 4.6e-02 2.3e-01 2.7e-04 7.0e-05 1.7e-04 8.3e-04 Scrap yard

Cm-244 5.9e-02 1.5e-02 3.7e-02 1.8e-01 2.2e-04 5.5e-05 1.4e-04 6.6e-04 Scrap yard

Cm-245 1.1e-01 2.8e-02 6.8e-02 3.3e-01 4.0e-04 1.0e-04 2.5e-04 1.2e-03 Scrap yard

Cm-246 1.1e-01 2.7e-02 6.7e-02 3.3e-01 4.0e-04 1.0e-04 2.5e-04 1.2e-03 Scrap yard

Cm-247 1.0e-01 2.6e-02 6.4e-02 3.1e-01 3.8e-04 9.7e-05 2.4e-04 1.2e-03 Scrap yard

Cm-248 3.9e-01 9.9e-02 2.5e-01 1.2e+00 1.5e-03 3.7e-04 9.1e-04 4.4e-03 Scrap yard

Bk-249 3.3e-04 8.3e-05 2.0e-04 1.0e-03 1.2e-06 3.1e-07 7.6e-07 3.7e-06 Scrap yard

Cf-248 1.2e-02 2.9e-03 7.3e-03 3.6e-02 4.3e-05 1.1e-05 2.7e-05 1.3e-04 Scrap yard

Cf-249 9.6e-02 2.5e-02 6.0e-02 2.9e-01 3.5e-04 9.1e-05 2.2e-04 1.1e-03 Scrap yard

Cf-250 4.9e-02 1.2e-02 3.1e-02 1.5e-01 1.8e-04 4.6e-05 1.1e-04 5.5e-04 Scrap yard

Cf-251 9.4e-02 2.4e-02 5.9e-02 2.9e-01 3.5e-04 8.9e-05 2.2e-04 1.1e-03 Scrap yard

Cf-252 3.7e-02 9.2e-03 2.3e-02 1.1e-01 1.4e-04 3.4e-05 8.5e-05 4.1e-04 Scrap yard

Cf-254 2.5e-01 6.6e-02 1.6e-01 7.3e-01 9.1e-04 2.4e-04 5.8e-04 2.7e-03 Scrap yard

Es-254 2.1e-02 5.9e-03 1.3e-02 6.2e-02 7.8e-05 2.2e-05 4.9e-05 2.3e-04 Scrap yard

a

 5th percentile to 95th percentile = 90% confidence interval
Chapter 5 Recycling and Disposal of Aluminum Scrap

5-25 NUREG-1640

Table 5.8 Normalized surficial effective dose equivalents to critical groups for aluminum Radionuclide

:Sv/y per Bq/cm2 mrem/y per pCi/cm2

Scenario

Mean

Percentilea

Mean

Percentilea

5th 50th 95th 5th 50th 95th

H-3 3.1e-06 0.0e+00 2.9e-09 1.1e-05 1.1e-08 0.0e+00 1.1e-11 4.2e-08 Leachate-industrial-scrap

C-14 5.0e-06 0.0e+00 0.0e+00 9.2e-06 1.8e-08 0.0e+00 0.0e+00 3.4e-08 Leachate-industrial-scrap

Na-22 3.2e-02 7.8e-03 2.0e-02 9.7e-02 1.2e-04 2.9e-05 7.5e-05 3.6e-04 Scrap yard

P-32 2.4e-05 4.2e-06 1.4e-05 7.4e-05 8.8e-08 1.5e-08 5.2e-08 2.7e-07 Scrap yard

S-35 9.2e-07 2.2e-07 5.8e-07 2.8e-06 3.4e-09 8.2e-10 2.1e-09 1.0e-08 Scrap yard

Cl-36 6.6e-05 0.0e+00 0.0e+00 2.6e-04 2.5e-07 0.0e+00 0.0e+00 9.8e-07 Leachate-industrial-scrap

K-40 2.5e-03 6.0e-04 1.6e-03 7.4e-03 9.1e-06 2.2e-06 5.7e-06 2.7e-05 Scrap yard

Ca-41 3.2e-05 0.0e+00 0.0e+00 1.4e-04 1.2e-07 0.0e+00 0.0e+00 5.1e-07 Leachate-industrial-scrap

Ca-45 4.3e-06 8.8e-07 2.7e-06 1.3e-05 1.6e-08 3.3e-09 9.9e-09 4.9e-08 Scrap yard

Sc-46 2.6e-02 6.3e-03 1.6e-02 7.8e-02 9.7e-05 2.3e-05 6.1e-05 2.9e-04 Scrap yard

Cr-51 2.7e-04 5.9e-05 1.7e-04 8.2e-04 9.9e-07 2.2e-07 6.1e-07 3.0e-06 Scrap yard

Mn-53 7.4e-07 4.7e-07 6.7e-07 1.4e-06 2.7e-09 1.7e-09 2.5e-09 5.1e-09 Aluminum cookware

Mn-54 6.3e-02 3.4e-02 5.7e-02 1.2e-01 2.3e-04 1.2e-04 2.1e-04 4.3e-04 Driver-engine block

Fe-55 3.5e-06 2.2e-06 3.2e-06 6.5e-06 1.3e-08 8.1e-09 1.2e-08 2.4e-08 Aluminum cookware

Fe-59 1.4e-02 3.2e-03 8.6e-03 4.2e-02 5.0e-05 1.2e-05 3.2e-05 1.5e-04 Scrap yard

Co-56 5.3e-02 1.8e-02 4.5e-02 1.2e-01 2.0e-04 6.7e-05 1.7e-04 4.3e-04 Driver-engine block

Co-57 8.0e-03 4.2e-03 7.2e-03 1.5e-02 3.0e-05 1.6e-05 2.7e-05 5.5e-05 Driver-engine block

Co-58 1.4e-02 4.3e-03 1.2e-02 3.1e-02 5.2e-05 1.6e-05 4.3e-05 1.2e-04 Driver-engine block

Co-60 2.9e-01 1.6e-01 2.6e-01 5.3e-01 1.1e-03 5.9e-04 9.6e-04 1.9e-03 Driver-engine block

Ni-59 2.5e-06 1.4e-06 2.2e-06 4.5e-06 9.1e-09 5.1e-09 8.2e-09 1.7e-08 Driver-engine block

Ni-63 3.9e-06 2.5e-06 3.6e-06 7.3e-06 1.5e-08 9.3e-09 1.3e-08 2.7e-08 Aluminum cookware

Zn-65 3.5e-02 1.8e-02 3.1e-02 6.4e-02 1.3e-04 6.7e-05 1.2e-04 2.4e-04 Driver-engine block

As-73 2.0e-05 6.6e-06 1.6e-05 4.2e-05 7.2e-08 2.4e-08 6.1e-08 1.6e-07 Driver-engine block

Se-75 1.1e-02 4.8e-03 9.9e-03 2.2e-02 4.2e-05 1.8e-05 3.7e-05 8.3e-05 Driver-engine block

Sr-85 5.7e-03 1.4e-03 3.6e-03 1.7e-02 2.1e-05 5.1e-06 1.3e-05 6.4e-05 Scrap yard

Sr-89 3.3e-05 8.3e-06 2.1e-05 9.8e-05 1.2e-07 3.1e-08 7.6e-08 3.6e-07 Scrap yard

Sr-90 2.9e-04 6.9e-05 1.8e-04 8.9e-04 1.1e-06 2.5e-07 6.7e-07 3.3e-06 Scrap yard

Y-91 8.8e-05 2.3e-05 5.6e-05 2.6e-04 3.3e-07 8.4e-08 2.1e-07 9.8e-07 Scrap yard

Zr-93 2.3e-05 5.7e-06 1.4e-05 7.0e-05 8.5e-08 2.1e-08 5.3e-08 2.6e-07 Scrap yard

Zr-95 1.2e-02 2.9e-03 7.5e-03 3.6e-02 4.4e-05 1.1e-05 2.8e-05 1.3e-04 Scrap yard

Nb-93m 8.1e-06 2.0e-06 5.1e-06 2.5e-05 3.0e-08 7.6e-09 1.9e-08 9.1e-08 Scrap yard

Nb-94 2.2e-01 1.2e-01 2.0e-01 4.0e-01 8.2e-04 4.6e-04 7.4e-04 1.5e-03 Driver-engine block

Nb-95 7.9e-03 1.8e-03 4.9e-03 2.4e-02 2.9e-05 6.7e-06 1.8e-05 8.9e-05 Scrap yard

Mo-93 1.0e-05 6.0e-06 9.1e-06 1.9e-05 3.7e-08 2.2e-08 3.4e-08 6.9e-08 Aluminum cookware

Tc-97 3.3e-05 0.0e+00 0.0e+00 1.4e-04 1.2e-07 0.0e+00 0.0e+00 5.1e-07 Leachate-industrial-scrap

Tc-97m 5.1e-06 1.4e-06 3.2e-06 1.5e-05 1.9e-08 5.0e-09 1.2e-08 5.6e-08 Scrap yard

Tc-99 2.8e-04 0.0e+00 0.0e+00 1.2e-03 1.1e-06 0.0e+00 0.0e+00 4.4e-06 Leachate-industrial-scrap

Ru-103 5.1e-03 1.2e-03 3.2e-03 1.5e-02 1.9e-05 4.4e-06 1.2e-05 5.7e-05 Scrap yard

Ru-106 2.2e-02 1.2e-02 2.0e-02 4.0e-02 8.0e-05 4.4e-05 7.2e-05 1.5e-04 Driver-engine block

a

 5th percentile to 95th percentile = 90% confidence interval
Recycling and Disposal of Aluminum Scrap Chapter 5

Table 5.8 Normalized surficial effective dose equivalents to critical groups for aluminum Radionuclide

:Sv/y per Bq/cm2 mrem/y per pCi/cm2

Scenario

Mean

Percentilea

Mean

Percentilea

5th 50th 95th 5th 50th 95th

NUREG-1640 5-26

Ag-108m 2.7e-01 1.5e-01 2.4e-01 4.9e-01 9.9e-04 5.5e-04 8.9e-04 1.8e-03 Driver-engine block

Ag-110m 1.9e-01 1.0e-01 1.7e-01 3.6e-01 7.2e-04 3.8e-04 6.5e-04 1.3e-03 Driver-engine block

Cd-109 2.2e-04 1.2e-04 2.0e-04 4.1e-04 8.3e-07 4.6e-07 7.5e-07 1.5e-06 Driver-engine block

Sn-113 7.4e-03 3.1e-03 6.4e-03 1.5e-02 2.7e-05 1.1e-05 2.4e-05 5.4e-05 Driver-engine block

Sb-124 2.3e-02 5.4e-03 1.4e-02 6.9e-02 8.3e-05 2.0e-05 5.3e-05 2.5e-04 Scrap yard

Sb-125 4.5e-02 2.4e-02 4.0e-02 8.2e-02 1.7e-04 9.0e-05 1.5e-04 3.1e-04 Driver-engine block

Te-123m 3.9e-03 1.6e-03 3.4e-03 7.7e-03 1.4e-05 6.1e-06 1.3e-05 2.9e-05 Driver-engine block

Te-127m 1.4e-04 5.7e-05 1.2e-04 2.8e-04 5.2e-07 2.1e-07 4.5e-07 1.0e-06 Driver-engine block

I-125 5.3e-05 1.2e-05 3.4e-05 1.6e-04 2.0e-07 4.5e-08 1.2e-07 6.1e-07 Scrap yard

I-129 1.4e-02 0.0e+00 0.0e+00 4.9e-02 5.0e-05 0.0e+00 0.0e+00 1.8e-04 Leachate-industrial-scrap

I-131 1.3e-03 1.2e-04 6.7e-04 4.6e-03 5.0e-06 4.5e-07 2.5e-06 1.7e-05 Scrap yard

Cs-134 2.3e-02 5.5e-03 1.4e-02 6.8e-02 8.4e-05 2.0e-05 5.3e-05 2.5e-04 Scrap yard

Cs-135 7.6e-06 1.1e-06 4.7e-06 2.4e-05 2.8e-08 4.0e-09 1.7e-08 9.0e-08 Scrap yard

Cs-137 8.3e-03 2.0e-03 5.2e-03 2.5e-02 3.1e-05 7.5e-06 1.9e-05 9.2e-05 Scrap yard

Ba-133 4.7e-03 1.1e-03 3.0e-03 1.4e-02 1.7e-05 4.2e-06 1.1e-05 5.2e-05 Scrap yard

Ce-139 1.3e-03 3.2e-04 8.3e-04 3.9e-03 4.9e-06 1.2e-06 3.1e-06 1.5e-05 Scrap yard

Ce-141 4.9e-04 1.1e-04 3.0e-04 1.5e-03 1.8e-06 4.2e-07 1.1e-06 5.5e-06 Scrap yard

Ce-144 8.1e-04 2.1e-04 5.1e-04 2.4e-03 3.0e-06 7.8e-07 1.9e-06 8.9e-06 Scrap yard

Pm-147 1.1e-05 2.8e-06 6.9e-06 3.3e-05 4.1e-08 1.0e-08 2.5e-08 1.2e-07 Scrap yard

Sm-151 8.0e-06 2.0e-06 5.0e-06 2.4e-05 3.0e-08 7.4e-09 1.9e-08 9.0e-08 Scrap yard

Eu-152 1.7e-02 4.1e-03 1.1e-02 5.1e-02 6.3e-05 1.5e-05 4.0e-05 1.9e-04 Scrap yard

Eu-154 1.7e-02 4.0e-03 1.0e-02 5.0e-02 6.1e-05 1.5e-05 3.9e-05 1.8e-04 Scrap yard

Eu-155 3.8e-04 9.5e-05 2.4e-04 1.1e-03 1.4e-06 3.5e-07 9.0e-07 4.3e-06 Scrap yard

Gd-153 4.7e-04 1.2e-04 3.0e-04 1.4e-03 1.8e-06 4.3e-07 1.1e-06 5.2e-06 Scrap yard

Tb-160 1.4e-02 3.3e-03 8.8e-03 4.2e-02 5.1e-05 1.2e-05 3.2e-05 1.6e-04 Scrap yard

Tm-170 3.4e-05 9.2e-06 2.2e-05 1.0e-04 1.3e-07 3.4e-08 8.1e-08 3.8e-07 Scrap yard

Tm-171 4.6e-06 1.3e-06 2.9e-06 1.4e-05 1.7e-08 4.7e-09 1.1e-08 5.0e-08 Scrap yard

Ta-182 3.0e-02 1.3e-02 2.6e-02 5.9e-02 1.1e-04 4.6e-05 9.7e-05 2.2e-04 Driver-engine block

W-181 3.4e-04 1.5e-04 3.0e-04 6.7e-04 1.3e-06 5.4e-07 1.1e-06 2.5e-06 Driver-engine block

W-185 2.3e-06 5.4e-07 1.5e-06 7.2e-06 8.6e-09 2.0e-09 5.4e-09 2.6e-08 Scrap yard

Os-185 1.3e-02 4.9e-03 1.1e-02 2.7e-02 4.9e-05 1.8e-05 4.2e-05 1.0e-04 Driver-engine block

Ir-192 1.2e-02 3.7e-03 9.9e-03 2.7e-02 4.4e-05 1.4e-05 3.7e-05 9.9e-05 Driver-engine block

Tl-204 1.1e-04 6.1e-05 1.0e-04 2.1e-04 4.2e-07 2.3e-07 3.7e-07 7.7e-07 Driver-engine block

Pb-210 4.2e-02 2.5e-02 3.8e-02 7.6e-02 1.5e-04 9.4e-05 1.4e-04 2.8e-04 Aluminum cookware

Bi-207 1.8e-01 9.5e-02 1.6e-01 3.2e-01 6.5e-04 3.5e-04 5.9e-04 1.2e-03 Driver-engine block

Po-210 3.5e-03 1.9e-03 3.1e-03 6.5e-03 1.3e-05 7.0e-06 1.2e-05 2.4e-05 Aluminum cookware

Ra-226 2.9e-02 7.5e-03 1.9e-02 8.7e-02 1.1e-04 2.8e-05 6.8e-05 3.2e-04 Scrap yard

Ra-228 1.7e-02 4.5e-03 1.1e-02 5.0e-02 6.3e-05 1.7e-05 4.0e-05 1.8e-04 Scrap yard

a

 5th percentile to 95th percentile = 90% confidence interval
Chapter 5 Recycling and Disposal of Aluminum Scrap

Table 5.8 Normalized surficial effective dose equivalents to critical groups for aluminum Radionuclide

:Sv/y per Bq/cm2 mrem/y per pCi/cm2

Scenario

Mean

Percentilea

Mean

Percentilea

5th 50th 95th 5th 50th 95th

5-27 NUREG-1640

Ac-227 3.6e-01 8.9e-02 2.2e-01 1.1e+00 1.3e-03 3.3e-04 8.2e-04 4.0e-03 Scrap yard

Th-228 8.6e-02 2.3e-02 5.4e-02 2.6e-01 3.2e-04 8.5e-05 2.0e-04 9.6e-04 Scrap yard

Th-229 5.6e-01 1.4e-01 3.5e-01 1.7e+00 2.1e-03 5.1e-04 1.3e-03 6.4e-03 Scrap yard

Th-230 8.4e-02 2.1e-02 5.3e-02 2.6e-01 3.1e-04 7.6e-05 1.9e-04 9.6e-04 Scrap yard

Th-232 4.2e-01 1.0e-01 2.6e-01 1.3e+00 1.6e-03 3.8e-04 9.8e-04 4.8e-03 Scrap yard

Pa-231 3.4e-01 8.4e-02 2.1e-01 1.0e+00 1.3e-03 3.1e-04 7.9e-04 3.8e-03 Scrap yard

U-232 1.7e-01 4.2e-02 1.1e-01 5.3e-01 6.4e-04 1.6e-04 4.0e-04 2.0e-03 Scrap yard

U-233 3.5e-02 8.6e-03 2.2e-02 1.1e-01 1.3e-04 3.2e-05 8.1e-05 4.0e-04 Scrap yard

U-234 3.4e-02 8.4e-03 2.1e-02 1.1e-01 1.3e-04 3.1e-05 7.9e-05 3.9e-04 Scrap yard

U-235 3.4e-02 8.4e-03 2.1e-02 1.0e-01 1.2e-04 3.1e-05 7.8e-05 3.8e-04 Scrap yard

U-236 3.2e-02 8.0e-03 2.0e-02 1.0e-01 1.2e-04 2.9e-05 7.5e-05 3.7e-04 Scrap yard

U-238 3.1e-02 7.7e-03 1.9e-02 9.5e-02 1.1e-04 2.8e-05 7.2e-05 3.5e-04 Scrap yard

Np-237 1.5e-01 3.6e-02 9.1e-02 4.4e-01 5.4e-04 1.3e-04 3.4e-04 1.6e-03 Scrap yard

Pu-236 3.8e-02 9.3e-03 2.4e-02 1.2e-01 1.4e-04 3.5e-05 8.7e-05 4.3e-04 Scrap yard

Pu-238 1.0e-01 2.6e-02 6.5e-02 3.2e-01 3.8e-04 9.5e-05 2.4e-04 1.2e-03 Scrap yard

Pu-239 1.1e-01 2.8e-02 7.1e-02 3.5e-01 4.2e-04 1.0e-04 2.6e-04 1.3e-03 Scrap yard

Pu-240 1.1e-01 2.8e-02 7.1e-02 3.5e-01 4.2e-04 1.0e-04 2.6e-04 1.3e-03 Scrap yard

Pu-241 2.2e-03 5.4e-04 1.4e-03 6.7e-03 8.1e-06 2.0e-06 5.0e-06 2.5e-05 Scrap yard

Pu-242 1.1e-01 2.7e-02 6.8e-02 3.3e-01 4.0e-04 9.9e-05 2.5e-04 1.2e-03 Scrap yard

Pu-244 1.1e-01 2.8e-02 7.0e-02 3.4e-01 4.1e-04 1.0e-04 2.6e-04 1.3e-03 Scrap yard

Am-241 1.2e-01 2.9e-02 7.3e-02 3.6e-01 4.3e-04 1.1e-04 2.7e-04 1.3e-03 Scrap yard

Am-242m 1.2e-01 2.9e-02 7.3e-02 3.5e-01 4.3e-04 1.1e-04 2.7e-04 1.3e-03 Scrap yard

Am-243 1.2e-01 2.9e-02 7.4e-02 3.6e-01 4.4e-04 1.1e-04 2.7e-04 1.3e-03 Scrap yard

Cm-242 4.2e-03 1.0e-03 2.6e-03 1.3e-02 1.6e-05 3.8e-06 9.7e-06 4.8e-05 Scrap yard

Cm-243 8.2e-02 2.0e-02 5.1e-02 2.5e-01 3.0e-04 7.6e-05 1.9e-04 9.3e-04 Scrap yard

Cm-244 6.5e-02 1.6e-02 4.1e-02 2.0e-01 2.4e-04 6.0e-05 1.5e-04 7.4e-04 Scrap yard

Cm-245 1.2e-01 3.0e-02 7.6e-02 3.7e-01 4.5e-04 1.1e-04 2.8e-04 1.4e-03 Scrap yard

Cm-246 1.2e-01 2.9e-02 7.4e-02 3.6e-01 4.4e-04 1.1e-04 2.8e-04 1.3e-03 Scrap yard

Cm-247 1.1e-01 2.9e-02 7.1e-02 3.5e-01 4.2e-04 1.1e-04 2.6e-04 1.3e-03 Scrap yard

Cm-248 4.4e-01 1.1e-01 2.7e-01 1.3e+00 1.6e-03 4.0e-04 1.0e-03 4.9e-03 Scrap yard

Bk-249 3.6e-04 9.0e-05 2.3e-04 1.1e-03 1.3e-06 3.3e-07 8.4e-07 4.1e-06 Scrap yard

Cf-248 1.3e-02 3.2e-03 8.1e-03 4.0e-02 4.8e-05 1.2e-05 3.0e-05 1.5e-04 Scrap yard

Cf-249 1.1e-01 2.7e-02 6.7e-02 3.2e-01 3.9e-04 9.9e-05 2.5e-04 1.2e-03 Scrap yard

Cf-250 5.5e-02 1.4e-02 3.4e-02 1.7e-01 2.0e-04 5.0e-05 1.3e-04 6.2e-04 Scrap yard

Cf-251 1.1e-01 2.6e-02 6.6e-02 3.2e-01 3.9e-04 9.7e-05 2.4e-04 1.2e-03 Scrap yard

Cf-252 4.1e-02 1.0e-02 2.5e-02 1.2e-01 1.5e-04 3.7e-05 9.4e-05 4.6e-04 Scrap yard

Cf-254 2.7e-01 7.1e-02 1.7e-01 8.2e-01 1.0e-03 2.6e-04 6.5e-04 3.0e-03 Scrap yard

Es-254 2.3e-02 6.4e-03 1.5e-02 6.9e-02 8.7e-05 2.4e-05 5.5e-05 2.6e-04 Scrap yard

a

 5th percentile to 95th percentile = 90% confidence interval
Recycling and Disposal of Aluminum Scrap Chapter 5

NUREG-1640 5-28

Table 5.9 Normalized mass-based effective doses to critical groups for aluminum

Radionuclide

:Sv/y per Bq/g mrem/y per pCi/g

Scenario

Mean

Percentilea

Mean

Percentilea

5th 50th 95th 5th 50th 95th

H-3 2.9e-06 0.0e+00 2.7e-09 1.1e-05 1.1e-08 0.0e+00 9.9e-12 3.9e-08 Leachate-industrial-scrap

C-14 4.6e-06 0.0e+00 0.0e+00 8.7e-06 1.7e-08 0.0e+00 0.0e+00 3.2e-08 Leachate-industrial-scrap

Na-22 2.9e-02 7.1e-03 1.8e-02 8.6e-02 1.1e-04 2.6e-05 6.7e-05 3.2e-04 Scrap yard

P-32 2.1e-05 3.8e-06 1.3e-05 6.7e-05 7.7e-08 1.4e-08 4.7e-08 2.5e-07 Scrap yard

S-35 1.3e-06 3.4e-07 8.3e-07 4.0e-06 4.9e-09 1.3e-09 3.1e-09 1.5e-08 Scrap yard

Cl-36 6.7e-05 0.0e+00 0.0e+00 2.7e-04 2.5e-07 0.0e+00 0.0e+00 1.0e-06 Leachate-industrial-scrap

K-40 2.2e-03 5.5e-04 1.4e-03 6.6e-03 8.2e-06 2.0e-06 5.2e-06 2.4e-05 Scrap yard

Ca-41 2.4e-05 0.0e+00 0.0e+00 1.0e-04 8.9e-08 0.0e+00 0.0e+00 3.9e-07 Leachate-industrial-scrap

Ca-45 4.3e-06 1.0e-06 2.7e-06 1.3e-05 1.6e-08 3.7e-09 1.0e-08 4.9e-08 Scrap yard

Sc-46 2.3e-02 5.7e-03 1.5e-02 7.1e-02 8.6e-05 2.1e-05 5.5e-05 2.6e-04 Scrap yard

Cr-51 2.4e-04 5.4e-05 1.5e-04 7.4e-04 8.8e-07 2.0e-07 5.5e-07 2.7e-06 Scrap yard

Mn-53 6.8e-07 4.5e-07 6.3e-07 1.3e-06 2.5e-09 1.7e-09 2.3e-09 4.7e-09 Aluminum cookware

Mn-54 5.5e-02 3.0e-02 4.9e-02 1.0e-01 2.0e-04 1.1e-04 1.8e-04 3.7e-04 Driver-engine block

Fe-55 6.3e-06 4.1e-06 5.8e-06 1.2e-05 2.3e-08 1.5e-08 2.1e-08 4.3e-08 Aluminum cookware

Fe-59 1.2e-02 2.9e-03 7.7e-03 3.7e-02 4.5e-05 1.1e-05 2.8e-05 1.4e-04 Scrap yard

Co-56 4.7e-02 1.6e-02 3.9e-02 1.0e-01 1.7e-04 5.9e-05 1.5e-04 3.7e-04 Driver-engine block

Co-57 7.0e-03 3.8e-03 6.3e-03 1.3e-02 2.6e-05 1.4e-05 2.3e-05 4.8e-05 Driver-engine block

Co-58 1.2e-02 3.8e-03 1.0e-02 2.7e-02 4.5e-05 1.4e-05 3.7e-05 1.0e-04 Driver-engine block

Co-60 2.5e-01 1.5e-01 2.3e-01 4.5e-01 9.3e-04 5.4e-04 8.5e-04 1.7e-03 Driver-engine block

Ni-59 2.1e-06 1.2e-06 1.9e-06 3.9e-06 7.9e-09 4.5e-09 7.2e-09 1.4e-08 Driver-engine block

Ni-63 3.4e-06 2.2e-06 3.1e-06 6.4e-06 1.3e-08 8.3e-09 1.2e-08 2.4e-08 Aluminum cookware

Zn-65 3.0e-02 1.6e-02 2.7e-02 5.6e-02 1.1e-04 6.0e-05 1.0e-04 2.1e-04 Driver-engine block

As-73 1.6e-05 5.6e-06 1.4e-05 3.6e-05 6.1e-08 2.1e-08 5.1e-08 1.3e-07 Driver-engine block

Se-75 1.0e-02 4.3e-03 8.7e-03 1.9e-02 3.7e-05 1.6e-05 3.2e-05 7.2e-05 Driver-engine block

Sr-85 5.1e-03 1.2e-03 3.2e-03 1.5e-02 1.9e-05 4.6e-06 1.2e-05 5.7e-05 Scrap yard

Sr-89 2.9e-05 7.5e-06 1.8e-05 8.8e-05 1.1e-07 2.8e-08 6.8e-08 3.2e-07 Scrap yard

Sr-90 1.9e-04 4.6e-05 1.2e-04 5.9e-04 7.1e-07 1.7e-07 4.5e-07 2.2e-06 Scrap yard

Y-91 7.5e-05 1.9e-05 4.8e-05 2.3e-04 2.8e-07 7.2e-08 1.8e-07 8.4e-07 Scrap yard

Zr-93 9.0e-06 2.3e-06 5.6e-06 2.7e-05 3.3e-08 8.5e-09 2.1e-08 1.0e-07 Scrap yard

Zr-95 1.1e-02 2.6e-03 6.7e-03 3.2e-02 3.9e-05 9.7e-06 2.5e-05 1.2e-04 Scrap yard

Nb-93m 2.7e-06 1.8e-06 2.5e-06 5.1e-06 1.0e-08 6.7e-09 9.3e-09 1.9e-08 Aluminum cookware

Nb-94 1.9e-01 1.1e-01 1.7e-01 3.5e-01 7.1e-04 4.1e-04 6.5e-04 1.3e-03 Driver-engine block

Nb-95 7.0e-03 1.6e-03 4.4e-03 2.1e-02 2.6e-05 6.1e-06 1.6e-05 7.9e-05 Scrap yard

Mo-93 5.2e-05 3.3e-05 4.8e-05 9.6e-05 1.9e-07 1.2e-07 1.8e-07 3.5e-07 Aluminum cookware

Tc-97 5.3e-05 0.0e+00 0.0e+00 2.3e-04 2.0e-07 0.0e+00 0.0e+00 8.5e-07 Leachate-industrial-scrap

Tc-97m 6.4e-06 1.7e-06 4.0e-06 1.9e-05 2.4e-08 6.4e-09 1.5e-08 7.0e-08 Scrap yard

Tc-99 5.0e-04 0.0e+00 0.0e+00 2.2e-03 1.9e-06 0.0e+00 0.0e+00 8.0e-06 Leachate-industrial-scrap

Ru-103 4.5e-03 1.1e-03 2.8e-03 1.4e-02 1.7e-05 3.9e-06 1.1e-05 5.1e-05 Scrap yard

Ru-106 1.9e-02 1.1e-02 1.7e-02 3.4e-02 7.0e-05 3.9e-05 6.3e-05 1.3e-04 Driver-engine block

a

 5th percentile to 95th percentile = 90% confidence interval
Chapter 5 Recycling and Disposal of Aluminum Scrap

Table 5.9 Normalized mass-based effective doses to critical groups for aluminum

Radionuclide

:Sv/y per Bq/g mrem/y per pCi/g

Scenario

Mean

Percentilea

Mean

Percentilea

5th 50th 95th 5th 50th 95th

5-29 NUREG-1640

Ag-108m 2.3e-01 1.4e-01 2.1e-01 4.2e-01 8.6e-04 5.0e-04 7.8e-04 1.6e-03 Driver-engine block

Ag-110m 1.7e-01 9.2e-02 1.5e-01 3.1e-01 6.3e-04 3.4e-04 5.6e-04 1.2e-03 Driver-engine block

Cd-109 2.0e-04 1.1e-04 1.8e-04 3.6e-04 7.3e-07 4.1e-07 6.6e-07 1.3e-06 Driver-engine block

Sn-113 6.4e-03 2.7e-03 5.6e-03 1.3e-02 2.4e-05 1.0e-05 2.1e-05 4.7e-05 Driver-engine block

Sb-124 2.0e-02 4.9e-03 1.3e-02 6.1e-02 7.5e-05 1.8e-05 4.7e-05 2.3e-04 Scrap yard

Sb-125 3.9e-02 2.2e-02 3.5e-02 7.1e-02 1.4e-04 8.1e-05 1.3e-04 2.6e-04 Driver-engine block

Te-123m 3.4e-03 1.5e-03 3.0e-03 6.6e-03 1.3e-05 5.4e-06 1.1e-05 2.5e-05 Driver-engine block

Te-127m 1.2e-04 5.1e-05 1.1e-04 2.4e-04 4.5e-07 1.9e-07 4.0e-07 9.1e-07 Driver-engine block

I-125 6.3e-05 1.4e-05 5.1e-05 1.5e-04 2.3e-07 5.1e-08 1.9e-07 5.6e-07 Airborne emissions

I-129 1.8e-02 0.0e+00 0.0e+00 6.4e-02 6.7e-05 0.0e+00 0.0e+00 2.4e-04 Leachate-industrial-scrap

I-131 1.2e-03 1.1e-04 6.0e-04 4.1e-03 4.5e-06 4.1e-07 2.2e-06 1.5e-05 Scrap yard

Cs-134 2.0e-02 5.0e-03 1.3e-02 6.0e-02 7.4e-05 1.9e-05 4.7e-05 2.2e-04 Scrap yard

Cs-135 6.6e-06 8.0e-07 4.1e-06 2.1e-05 2.4e-08 3.0e-09 1.5e-08 8.0e-08 Scrap yard

Cs-137 7.4e-03 1.8e-03 4.7e-03 2.2e-02 2.7e-05 6.8e-06 1.7e-05 8.2e-05 Scrap yard

Ba-133 4.2e-03 1.0e-03 2.7e-03 1.2e-02 1.5e-05 3.8e-06 9.8e-06 4.6e-05 Scrap yard

Ce-139 1.2e-03 2.9e-04 7.5e-04 3.6e-03 4.4e-06 1.1e-06 2.8e-06 1.3e-05 Scrap yard

Ce-141 4.4e-04 1.0e-04 2.7e-04 1.3e-03 1.6e-06 3.8e-07 1.0e-06 5.0e-06 Scrap yard

Ce-144 6.9e-04 1.8e-04 4.4e-04 2.1e-03 2.5e-06 6.5e-07 1.6e-06 7.7e-06 Scrap yard

Pm-147 4.7e-06 1.2e-06 3.0e-06 1.4e-05 1.8e-08 4.6e-09 1.1e-08 5.3e-08 Scrap yard

Sm-151 3.4e-06 8.8e-07 2.2e-06 1.0e-05 1.3e-08 3.3e-09 8.0e-09 3.8e-08 Scrap yard

Eu-152 1.5e-02 3.8e-03 9.6e-03 4.5e-02 5.6e-05 1.4e-05 3.6e-05 1.7e-04 Scrap yard

Eu-154 1.5e-02 3.7e-03 9.4e-03 4.4e-02 5.5e-05 1.4e-05 3.5e-05 1.6e-04 Scrap yard

Eu-155 3.4e-04 8.5e-05 2.2e-04 1.0e-03 1.3e-06 3.1e-07 8.0e-07 3.8e-06 Scrap yard

Gd-153 4.2e-04 1.0e-04 2.7e-04 1.3e-03 1.6e-06 3.9e-07 9.9e-07 4.7e-06 Scrap yard

Tb-160 1.2e-02 3.0e-03 7.9e-03 3.8e-02 4.6e-05 1.1e-05 2.9e-05 1.4e-04 Scrap yard

Tm-170 3.0e-05 8.3e-06 1.9e-05 8.9e-05 1.1e-07 3.1e-08 7.1e-08 3.3e-07 Scrap yard

Tm-171 3.1e-06 8.7e-07 1.9e-06 9.1e-06 1.1e-08 3.2e-09 7.2e-09 3.4e-08 Scrap yard

Ta-182 2.6e-02 1.1e-02 2.3e-02 5.1e-02 9.7e-05 4.1e-05 8.5e-05 1.9e-04 Driver-engine block

W-181 2.9e-04 1.3e-04 2.6e-04 5.8e-04 1.1e-06 4.7e-07 9.6e-07 2.1e-06 Driver-engine block

W-185 2.1e-06 4.7e-07 1.3e-06 6.4e-06 7.7e-09 1.8e-09 4.8e-09 2.4e-08 Scrap yard

Os-185 1.1e-02 4.4e-03 9.9e-03 2.4e-02 4.2e-05 1.6e-05 3.7e-05 8.8e-05 Driver-engine block

Ir-192 1.0e-02 3.3e-03 8.6e-03 2.3e-02 3.8e-05 1.2e-05 3.2e-05 8.5e-05 Driver-engine block

Tl-204 9.8e-05 5.5e-05 8.9e-05 1.8e-04 3.6e-07 2.0e-07 3.3e-07 6.6e-07 Driver-engine block

Pb-210 1.8e-02 1.1e-02 1.6e-02 3.2e-02 6.5e-05 4.1e-05 5.9e-05 1.2e-04 Aluminum cookware

Bi-207 1.5e-01 8.6e-02 1.4e-01 2.8e-01 5.7e-04 3.2e-04 5.1e-04 1.0e-03 Driver-engine block

Po-210 3.0e-03 7.6e-04 1.9e-03 9.0e-03 1.1e-05 2.8e-06 6.9e-06 3.3e-05 Scrap yard

Ra-226 2.7e-02 7.1e-03 1.7e-02 8.0e-02 9.9e-05 2.6e-05 6.3e-05 3.0e-04 Scrap yard

Ra-228 1.6e-02 4.5e-03 1.0e-02 4.9e-02 6.1e-05 1.7e-05 3.9e-05 1.8e-04 Scrap yard

a

 5th percentile to 95th percentile = 90% confidence interval
Recycling and Disposal of Aluminum Scrap Chapter 5

Table 5.9 Normalized mass-based effective doses to critical groups for aluminum

Radionuclide

:Sv/y per Bq/g mrem/y per pCi/g

Scenario

Mean

Percentilea

Mean

Percentilea

5th 50th 95th 5th 50th 95th

NUREG-1640 5-30

Ac-227 7.7e-02 2.0e-02 4.8e-02 2.3e-01 2.8e-04 7.4e-05 1.8e-04 8.7e-04 Scrap yard

Th-228 4.8e-02 1.3e-02 3.0e-02 1.4e-01 1.8e-04 4.9e-05 1.1e-04 5.3e-04 Scrap yard

Th-229 1.0e-01 2.6e-02 6.4e-02 3.1e-01 3.7e-04 9.6e-05 2.4e-04 1.1e-03 Scrap yard

Th-230 3.5e-02 8.8e-03 2.2e-02 1.1e-01 1.3e-04 3.2e-05 8.1e-05 3.9e-04 Scrap yard

Th-232 3.7e-02 9.2e-03 2.3e-02 1.1e-01 1.4e-04 3.4e-05 8.5e-05 4.1e-04 Scrap yard

Pa-231 1.1e-01 2.9e-02 7.1e-02 3.5e-01 4.2e-04 1.1e-04 2.6e-04 1.3e-03 Scrap yard

U-232 3.2e-02 8.1e-03 2.0e-02 9.7e-02 1.2e-04 3.0e-05 7.4e-05 3.6e-04 Scrap yard

U-233 7.6e-03 1.9e-03 4.7e-03 2.3e-02 2.8e-05 7.1e-06 1.8e-05 8.5e-05 Scrap yard

U-234 7.4e-03 1.9e-03 4.6e-03 2.3e-02 2.7e-05 6.9e-06 1.7e-05 8.3e-05 Scrap yard

U-235 8.4e-03 2.3e-03 5.3e-03 2.6e-02 3.1e-05 8.3e-06 2.0e-05 9.5e-05 Scrap yard

U-236 6.9e-03 1.7e-03 4.3e-03 2.1e-02 2.5e-05 6.4e-06 1.6e-05 7.8e-05 Scrap yard

U-238 6.7e-03 1.7e-03 4.2e-03 2.1e-02 2.5e-05 6.4e-06 1.6e-05 7.6e-05 Scrap yard

Np-237 2.1e-02 5.4e-03 1.3e-02 6.3e-02 7.7e-05 2.0e-05 4.8e-05 2.3e-04 Scrap yard

Pu-236 1.5e-02 3.9e-03 9.7e-03 4.7e-02 5.7e-05 1.4e-05 3.6e-05 1.7e-04 Scrap yard

Pu-238 3.7e-02 9.4e-03 2.3e-02 1.1e-01 1.4e-04 3.5e-05 8.7e-05 4.2e-04 Scrap yard

Pu-239 4.1e-02 1.0e-02 2.6e-02 1.2e-01 1.5e-04 3.8e-05 9.5e-05 4.6e-04 Scrap yard

Pu-240 4.1e-02 1.0e-02 2.6e-02 1.2e-01 1.5e-04 3.8e-05 9.5e-05 4.6e-04 Scrap yard

Pu-241 7.4e-04 1.9e-04 4.6e-04 2.3e-03 2.7e-06 6.9e-07 1.7e-06 8.4e-06 Scrap yard

Pu-242 3.8e-02 9.6e-03 2.4e-02 1.2e-01 1.4e-04 3.6e-05 8.9e-05 4.3e-04 Scrap yard

Pu-244 4.2e-02 1.1e-02 2.7e-02 1.3e-01 1.6e-04 4.1e-05 9.9e-05 4.8e-04 Scrap yard

Am-241 3.4e-02 8.6e-03 2.1e-02 1.0e-01 1.3e-04 3.2e-05 7.9e-05 3.8e-04 Scrap yard

Am-242m 3.4e-02 8.6e-03 2.1e-02 1.0e-01 1.3e-04 3.2e-05 7.9e-05 3.8e-04 Scrap yard

Am-243 3.6e-02 9.2e-03 2.2e-02 1.1e-01 1.3e-04 3.4e-05 8.3e-05 4.1e-04 Scrap yard

Cm-242 3.8e-03 9.5e-04 2.4e-03 1.2e-02 1.4e-05 3.5e-06 8.9e-06 4.3e-05 Scrap yard

Cm-243 2.6e-02 6.8e-03 1.7e-02 8.1e-02 9.7e-05 2.5e-05 6.1e-05 3.0e-04 Scrap yard

Cm-244 2.2e-02 5.4e-03 1.4e-02 6.6e-02 8.0e-05 2.0e-05 5.0e-05 2.4e-04 Scrap yard

Cm-245 3.6e-02 9.0e-03 2.2e-02 1.1e-01 1.3e-04 3.3e-05 8.3e-05 4.0e-04 Scrap yard

Cm-246 3.5e-02 8.8e-03 2.2e-02 1.1e-01 1.3e-04 3.2e-05 8.1e-05 3.9e-04 Scrap yard

Cm-247 3.5e-02 9.3e-03 2.2e-02 1.1e-01 1.3e-04 3.4e-05 8.2e-05 4.0e-04 Scrap yard

Cm-248 1.2e-01 3.1e-02 7.6e-02 3.7e-01 4.5e-04 1.1e-04 2.8e-04 1.4e-03 Scrap yard

Bk-249 1.3e-04 3.3e-05 8.3e-05 4.0e-04 4.9e-07 1.2e-07 3.1e-07 1.5e-06 Scrap yard

Cf-248 6.8e-03 1.7e-03 4.3e-03 2.1e-02 2.5e-05 6.4e-06 1.6e-05 7.8e-05 Scrap yard

Cf-249 6.1e-02 1.6e-02 3.8e-02 1.9e-01 2.3e-04 5.8e-05 1.4e-04 6.9e-04 Scrap yard

Cf-250 2.8e-02 7.0e-03 1.7e-02 8.4e-02 1.0e-04 2.6e-05 6.4e-05 3.1e-04 Scrap yard

Cf-251 5.9e-02 1.5e-02 3.7e-02 1.8e-01 2.2e-04 5.6e-05 1.4e-04 6.7e-04 Scrap yard

Cf-252 1.5e-02 3.9e-03 9.7e-03 4.7e-02 5.7e-05 1.4e-05 3.6e-05 1.7e-04 Scrap yard

Cf-254 2.2e-01 5.5e-02 1.4e-01 6.4e-01 8.0e-04 2.1e-04 5.1e-04 2.4e-03 Scrap yard

Es-254 1.8e-02 5.1e-03 1.2e-02 5.4e-02 6.7e-05 1.9e-05 4.3e-05 2.0e-04 Scrap yard

a

 5th percentile to 95th percentile = 90% confidence interval
Chapter 5 Recycling and Disposal of Aluminum Scrap

5-31 NUREG-1640

Table 5.10 Normalized surficial effective doses to critical groups for aluminum

Radionuclide

:Sv/y per Bq/cm2 mrem/y per pCi/cm2

Scenario

Mean

Percentilea

Mean

Percentilea

5th 50th 95th 5th 50th 95th

H-3 3.2e-06 0.0e+00 3.0e-09 1.2e-05 1.2e-08 0.0e+00 1.1e-11 4.4e-08 Leachate-industrial-scrap

C-14 5.1e-06 0.0e+00 0.0e+00 9.4e-06 1.9e-08 0.0e+00 0.0e+00 3.5e-08 Leachate-industrial-scrap

Na-22 3.2e-02 7.7e-03 2.0e-02 9.6e-02 1.2e-04 2.9e-05 7.5e-05 3.5e-04 Scrap yard

P-32 2.3e-05 4.1e-06 1.4e-05 7.3e-05 8.6e-08 1.5e-08 5.2e-08 2.7e-07 Scrap yard

S-35 1.5e-06 3.7e-07 9.3e-07 4.5e-06 5.5e-09 1.4e-09 3.4e-09 1.7e-08 Scrap yard

Cl-36 7.5e-05 0.0e+00 0.0e+00 3.0e-04 2.8e-07 0.0e+00 0.0e+00 1.1e-06 Leachate-industrial-scrap

K-40 2.5e-03 6.0e-04 1.6e-03 7.4e-03 9.1e-06 2.2e-06 5.7e-06 2.7e-05 Scrap yard

Ca-41 2.7e-05 0.0e+00 0.0e+00 1.2e-04 9.9e-08 0.0e+00 0.0e+00 4.3e-07 Leachate-industrial-scrap

Ca-45 4.8e-06 1.1e-06 3.0e-06 1.5e-05 1.8e-08 4.0e-09 1.1e-08 5.4e-08 Scrap yard

Sc-46 2.6e-02 6.3e-03 1.6e-02 7.8e-02 9.6e-05 2.3e-05 6.1e-05 2.9e-04 Scrap yard

Cr-51 2.7e-04 5.9e-05 1.7e-04 8.2e-04 9.9e-07 2.2e-07 6.1e-07 3.0e-06 Scrap yard

Mn-53 7.6e-07 4.8e-07 6.9e-07 1.4e-06 2.8e-09 1.8e-09 2.6e-09 5.2e-09 Aluminum cookware

Mn-54 6.1e-02 3.3e-02 5.5e-02 1.1e-01 2.3e-04 1.2e-04 2.0e-04 4.1e-04 Driver-engine block

Fe-55 7.0e-06 4.4e-06 6.4e-06 1.3e-05 2.6e-08 1.6e-08 2.3e-08 4.8e-08 Aluminum cookware

Fe-59 1.3e-02 3.2e-03 8.5e-03 4.2e-02 5.0e-05 1.2e-05 3.1e-05 1.5e-04 Scrap yard

Co-56 5.2e-02 1.8e-02 4.4e-02 1.1e-01 1.9e-04 6.5e-05 1.6e-04 4.2e-04 Driver-engine block

Co-57 7.8e-03 4.1e-03 7.0e-03 1.4e-02 2.9e-05 1.5e-05 2.6e-05 5.3e-05 Driver-engine block

Co-58 1.4e-02 4.2e-03 1.1e-02 3.0e-02 5.0e-05 1.5e-05 4.1e-05 1.1e-04 Driver-engine block

Co-60 2.8e-01 1.6e-01 2.5e-01 5.1e-01 1.0e-03 5.8e-04 9.4e-04 1.9e-03 Driver-engine block

Ni-59 2.4e-06 1.3e-06 2.1e-06 4.3e-06 8.8e-09 4.9e-09 7.9e-09 1.6e-08 Driver-engine block

Ni-63 3.8e-06 2.4e-06 3.4e-06 7.0e-06 1.4e-08 8.9e-09 1.3e-08 2.6e-08 Aluminum cookware

Zn-65 3.4e-02 1.8e-02 3.0e-02 6.2e-02 1.3e-04 6.5e-05 1.1e-04 2.3e-04 Driver-engine block

As-73 1.8e-05 6.2e-06 1.5e-05 4.0e-05 6.8e-08 2.3e-08 5.7e-08 1.5e-07 Driver-engine block

Se-75 1.1e-02 4.7e-03 9.7e-03 2.2e-02 4.1e-05 1.7e-05 3.6e-05 8.0e-05 Driver-engine block

Sr-85 5.7e-03 1.4e-03 3.6e-03 1.7e-02 2.1e-05 5.0e-06 1.3e-05 6.4e-05 Scrap yard

Sr-89 3.2e-05 8.2e-06 2.0e-05 9.7e-05 1.2e-07 3.0e-08 7.5e-08 3.6e-07 Scrap yard

Sr-90 2.1e-04 5.1e-05 1.3e-04 6.6e-04 7.9e-07 1.9e-07 5.0e-07 2.4e-06 Scrap yard

Y-91 8.4e-05 2.1e-05 5.3e-05 2.5e-04 3.1e-07 7.9e-08 2.0e-07 9.3e-07 Scrap yard

Zr-93 1.0e-05 2.5e-06 6.3e-06 3.1e-05 3.7e-08 9.3e-09 2.3e-08 1.1e-07 Scrap yard

Zr-95 1.2e-02 2.9e-03 7.5e-03 3.6e-02 4.4e-05 1.1e-05 2.8e-05 1.3e-04 Scrap yard

Nb-93m 3.1e-06 1.9e-06 2.8e-06 5.7e-06 1.1e-08 7.2e-09 1.0e-08 2.1e-08 Aluminum cookware

Nb-94 2.1e-01 1.2e-01 1.9e-01 3.9e-01 7.9e-04 4.4e-04 7.2e-04 1.5e-03 Driver-engine block

Nb-95 7.8e-03 1.8e-03 4.9e-03 2.4e-02 2.9e-05 6.7e-06 1.8e-05 8.8e-05 Scrap yard

Mo-93 5.8e-05 3.5e-05 5.3e-05 1.1e-04 2.1e-07 1.3e-07 2.0e-07 4.0e-07 Aluminum cookware

Tc-97 6.0e-05 0.0e+00 0.0e+00 2.5e-04 2.2e-07 0.0e+00 0.0e+00 9.2e-07 Leachate-industrial-scrap

Tc-97m 7.1e-06 1.9e-06 4.5e-06 2.1e-05 2.6e-08 7.0e-09 1.7e-08 7.8e-08 Scrap yard

Tc-99 5.6e-04 0.0e+00 0.0e+00 2.3e-03 2.1e-06 0.0e+00 0.0e+00 8.6e-06 Leachate-industrial-scrap

Ru-103 5.0e-03 1.2e-03 3.2e-03 1.5e-02 1.9e-05 4.3e-06 1.2e-05 5.7e-05 Scrap yard

Ru-106 2.1e-02 1.1e-02 1.9e-02 3.9e-02 7.8e-05 4.2e-05 7.0e-05 1.4e-04 Driver-engine block

a

 5th percentile to 95th percentile = 90% confidence interval
Recycling and Disposal of Aluminum Scrap Chapter 5

Table 5.10 Normalized surficial effective doses to critical groups for aluminum

Radionuclide

:Sv/y per Bq/cm2 mrem/y per pCi/cm2

Scenario

Mean

Percentilea

Mean

Percentilea

5th 50th 95th 5th 50th 95th

NUREG-1640 5-32

Ag-108m 2.6e-01 1.5e-01 2.3e-01 4.7e-01 9.6e-04 5.4e-04 8.7e-04 1.7e-03 Driver-engine block

Ag-110m 1.9e-01 9.9e-02 1.7e-01 3.5e-01 7.0e-04 3.7e-04 6.3e-04 1.3e-03 Driver-engine block

Cd-109 2.2e-04 1.2e-04 2.0e-04 4.0e-04 8.1e-07 4.5e-07 7.3e-07 1.5e-06 Driver-engine block

Sn-113 7.2e-03 3.0e-03 6.2e-03 1.4e-02 2.7e-05 1.1e-05 2.3e-05 5.3e-05 Driver-engine block

Sb-124 2.2e-02 5.4e-03 1.4e-02 6.8e-02 8.3e-05 2.0e-05 5.3e-05 2.5e-04 Scrap yard

Sb-125 4.3e-02 2.3e-02 3.9e-02 8.0e-02 1.6e-04 8.7e-05 1.4e-04 3.0e-04 Driver-engine block

Te-123m 3.8e-03 1.6e-03 3.3e-03 7.5e-03 1.4e-05 5.9e-06 1.2e-05 2.8e-05 Driver-engine block

Te-127m 1.4e-04 5.5e-05 1.2e-04 2.8e-04 5.0e-07 2.0e-07 4.4e-07 1.0e-06 Driver-engine block

I-125 7.0e-05 1.5e-05 5.6e-05 1.7e-04 2.6e-07 5.5e-08 2.1e-07 6.2e-07 Airborne emissions

I-129 2.0e-02 0.0e+00 0.0e+00 7.2e-02 7.4e-05 0.0e+00 0.0e+00 2.7e-04 Leachate-industrial-scrap

I-131 1.3e-03 1.2e-04 6.7e-04 4.6e-03 5.0e-06 4.5e-07 2.5e-06 1.7e-05 Scrap yard

Cs-134 2.2e-02 5.5e-03 1.4e-02 6.7e-02 8.3e-05 2.0e-05 5.2e-05 2.5e-04 Scrap yard

Cs-135 7.4e-06 8.8e-07 4.5e-06 2.4e-05 2.7e-08 3.3e-09 1.7e-08 8.8e-08 Scrap yard

Cs-137 8.2e-03 2.0e-03 5.2e-03 2.5e-02 3.0e-05 7.4e-06 1.9e-05 9.2e-05 Scrap yard

Ba-133 4.7e-03 1.1e-03 2.9e-03 1.4e-02 1.7e-05 4.2e-06 1.1e-05 5.2e-05 Scrap yard

Ce-139 1.3e-03 3.2e-04 8.3e-04 3.9e-03 4.9e-06 1.2e-06 3.1e-06 1.5e-05 Scrap yard

Ce-141 4.9e-04 1.1e-04 3.0e-04 1.5e-03 1.8e-06 4.1e-07 1.1e-06 5.5e-06 Scrap yard

Ce-144 7.7e-04 1.9e-04 4.8e-04 2.3e-03 2.8e-06 7.2e-07 1.8e-06 8.4e-06 Scrap yard

Pm-147 5.3e-06 1.4e-06 3.3e-06 1.6e-05 2.0e-08 5.0e-09 1.2e-08 5.9e-08 Scrap yard

Sm-151 3.8e-06 9.6e-07 2.4e-06 1.2e-05 1.4e-08 3.6e-09 8.9e-09 4.3e-08 Scrap yard

Eu-152 1.7e-02 4.1e-03 1.1e-02 5.1e-02 6.2e-05 1.5e-05 3.9e-05 1.9e-04 Scrap yard

Eu-154 1.6e-02 4.0e-03 1.0e-02 4.9e-02 6.1e-05 1.5e-05 3.8e-05 1.8e-04 Scrap yard

Eu-155 3.8e-04 9.3e-05 2.4e-04 1.1e-03 1.4e-06 3.4e-07 8.9e-07 4.2e-06 Scrap yard

Gd-153 4.7e-04 1.1e-04 3.0e-04 1.4e-03 1.7e-06 4.2e-07 1.1e-06 5.2e-06 Scrap yard

Tb-160 1.4e-02 3.3e-03 8.7e-03 4.2e-02 5.1e-05 1.2e-05 3.2e-05 1.5e-04 Scrap yard

Tm-170 3.4e-05 9.0e-06 2.1e-05 9.9e-05 1.2e-07 3.3e-08 7.9e-08 3.7e-07 Scrap yard

Tm-171 3.4e-06 9.5e-07 2.2e-06 1.0e-05 1.3e-08 3.5e-09 8.0e-09 3.7e-08 Scrap yard

Ta-182 2.9e-02 1.2e-02 2.5e-02 5.8e-02 1.1e-04 4.5e-05 9.4e-05 2.1e-04 Driver-engine block

W-181 3.3e-04 1.4e-04 2.9e-04 6.4e-04 1.2e-06 5.1e-07 1.1e-06 2.4e-06 Driver-engine block

W-185 2.3e-06 5.2e-07 1.5e-06 7.1e-06 8.6e-09 1.9e-09 5.4e-09 2.6e-08 Scrap yard

Os-185 1.3e-02 4.8e-03 1.1e-02 2.7e-02 4.7e-05 1.8e-05 4.0e-05 9.8e-05 Driver-engine block

Ir-192 1.2e-02 3.6e-03 9.6e-03 2.6e-02 4.3e-05 1.3e-05 3.5e-05 9.6e-05 Driver-engine block

Tl-204 1.1e-04 5.9e-05 9.8e-05 2.0e-04 4.0e-07 2.2e-07 3.6e-07 7.5e-07 Driver-engine block

Pb-210 2.0e-02 1.2e-02 1.8e-02 3.6e-02 7.2e-05 4.4e-05 6.6e-05 1.3e-04 Aluminum cookware

Bi-207 1.7e-01 9.3e-02 1.5e-01 3.2e-01 6.3e-04 3.4e-04 5.7e-04 1.2e-03 Driver-engine block

Po-210 3.3e-03 8.3e-04 2.1e-03 9.9e-03 1.2e-05 3.1e-06 7.6e-06 3.7e-05 Scrap yard

Ra-226 3.0e-02 7.7e-03 1.9e-02 8.8e-02 1.1e-04 2.8e-05 7.0e-05 3.2e-04 Scrap yard

Ra-228 1.8e-02 5.0e-03 1.2e-02 5.4e-02 6.8e-05 1.8e-05 4.3e-05 2.0e-04 Scrap yard

a

 5th percentile to 95th percentile = 90% confidence interval
Chapter 5 Recycling and Disposal of Aluminum Scrap

Table 5.10 Normalized surficial effective doses to critical groups for aluminum

Radionuclide

:Sv/y per Bq/cm2 mrem/y per pCi/cm2

Scenario

Mean

Percentilea

Mean

Percentilea

5th 50th 95th 5th 50th 95th

5-33 NUREG-1640

Ac-227 8.5e-02 2.2e-02 5.3e-02 2.6e-01 3.2e-04 8.0e-05 2.0e-04 9.6e-04 Scrap yard

Th-228 5.3e-02 1.5e-02 3.4e-02 1.6e-01 2.0e-04 5.4e-05 1.2e-04 5.8e-04 Scrap yard

Th-229 1.1e-01 2.8e-02 7.0e-02 3.5e-01 4.2e-04 1.0e-04 2.6e-04 1.3e-03 Scrap yard

Th-230 3.9e-02 9.5e-03 2.4e-02 1.2e-01 1.4e-04 3.5e-05 8.9e-05 4.4e-04 Scrap yard

Th-232 4.1e-02 1.0e-02 2.5e-02 1.2e-01 1.5e-04 3.7e-05 9.4e-05 4.6e-04 Scrap yard

Pa-231 1.3e-01 3.1e-02 7.9e-02 3.9e-01 4.7e-04 1.2e-04 2.9e-04 1.4e-03 Scrap yard

U-232 3.5e-02 8.8e-03 2.2e-02 1.1e-01 1.3e-04 3.3e-05 8.2e-05 4.0e-04 Scrap yard

U-233 8.4e-03 2.1e-03 5.3e-03 2.6e-02 3.1e-05 7.7e-06 1.9e-05 9.6e-05 Scrap yard

U-234 8.2e-03 2.0e-03 5.1e-03 2.5e-02 3.1e-05 7.5e-06 1.9e-05 9.3e-05 Scrap yard

U-235 9.3e-03 2.5e-03 5.9e-03 2.8e-02 3.5e-05 9.1e-06 2.2e-05 1.0e-04 Scrap yard

U-236 7.7e-03 1.9e-03 4.8e-03 2.3e-02 2.8e-05 7.0e-06 1.8e-05 8.7e-05 Scrap yard

U-238 7.5e-03 1.9e-03 4.7e-03 2.3e-02 2.8e-05 7.0e-06 1.7e-05 8.5e-05 Scrap yard

Np-237 2.3e-02 5.9e-03 1.4e-02 7.0e-02 8.5e-05 2.2e-05 5.4e-05 2.6e-04 Scrap yard

Pu-236 1.7e-02 4.2e-03 1.1e-02 5.3e-02 6.4e-05 1.6e-05 4.0e-05 1.9e-04 Scrap yard

Pu-238 4.2e-02 1.0e-02 2.6e-02 1.3e-01 1.5e-04 3.8e-05 9.6e-05 4.7e-04 Scrap yard

Pu-239 4.6e-02 1.1e-02 2.8e-02 1.4e-01 1.7e-04 4.1e-05 1.1e-04 5.2e-04 Scrap yard

Pu-240 4.6e-02 1.1e-02 2.8e-02 1.4e-01 1.7e-04 4.1e-05 1.1e-04 5.2e-04 Scrap yard

Pu-241 8.2e-04 2.0e-04 5.1e-04 2.5e-03 3.1e-06 7.5e-07 1.9e-06 9.3e-06 Scrap yard

Pu-242 4.3e-02 1.0e-02 2.7e-02 1.3e-01 1.6e-04 3.9e-05 9.8e-05 4.8e-04 Scrap yard

Pu-244 4.7e-02 1.2e-02 3.0e-02 1.5e-01 1.8e-04 4.5e-05 1.1e-04 5.4e-04 Scrap yard

Am-241 3.8e-02 9.3e-03 2.4e-02 1.2e-01 1.4e-04 3.4e-05 8.7e-05 4.3e-04 Scrap yard

Am-242m 3.8e-02 9.3e-03 2.4e-02 1.2e-01 1.4e-04 3.5e-05 8.7e-05 4.3e-04 Scrap yard

Am-243 4.0e-02 1.0e-02 2.5e-02 1.2e-01 1.5e-04 3.7e-05 9.2e-05 4.5e-04 Scrap yard

Cm-242 4.3e-03 1.0e-03 2.7e-03 1.3e-02 1.6e-05 3.8e-06 9.8e-06 4.8e-05 Scrap yard

Cm-243 2.9e-02 7.3e-03 1.8e-02 9.0e-02 1.1e-04 2.7e-05 6.8e-05 3.3e-04 Scrap yard

Cm-244 2.4e-02 5.9e-03 1.5e-02 7.4e-02 8.9e-05 2.2e-05 5.6e-05 2.7e-04 Scrap yard

Cm-245 4.0e-02 9.8e-03 2.5e-02 1.2e-01 1.5e-04 3.6e-05 9.1e-05 4.5e-04 Scrap yard

Cm-246 3.9e-02 9.5e-03 2.4e-02 1.2e-01 1.4e-04 3.5e-05 8.9e-05 4.4e-04 Scrap yard

Cm-247 3.9e-02 1.0e-02 2.5e-02 1.2e-01 1.5e-04 3.7e-05 9.1e-05 4.4e-04 Scrap yard

Cm-248 1.4e-01 3.3e-02 8.5e-02 4.2e-01 5.0e-04 1.2e-04 3.1e-04 1.5e-03 Scrap yard

Bk-249 1.5e-04 3.6e-05 9.2e-05 4.5e-04 5.4e-07 1.3e-07 3.4e-07 1.7e-06 Scrap yard

Cf-248 7.6e-03 1.9e-03 4.8e-03 2.3e-02 2.8e-05 6.9e-06 1.8e-05 8.6e-05 Scrap yard

Cf-249 6.8e-02 1.7e-02 4.3e-02 2.1e-01 2.5e-04 6.4e-05 1.6e-04 7.7e-04 Scrap yard

Cf-250 3.1e-02 7.6e-03 1.9e-02 9.5e-02 1.1e-04 2.8e-05 7.1e-05 3.5e-04 Scrap yard

Cf-251 6.6e-02 1.6e-02 4.1e-02 2.0e-01 2.4e-04 6.0e-05 1.5e-04 7.5e-04 Scrap yard

Cf-252 1.7e-02 4.2e-03 1.1e-02 5.3e-02 6.4e-05 1.6e-05 4.0e-05 1.9e-04 Scrap yard

Cf-254 2.4e-01 6.1e-02 1.5e-01 7.2e-01 8.9e-04 2.2e-04 5.6e-04 2.7e-03 Scrap yard

Es-254 2.0e-02 5.5e-03 1.3e-02 6.0e-02 7.5e-05 2.0e-05 4.8e-05 2.2e-04 Scrap yard

a

 5th percentile to 95th percentile = 90% confidence interval
Recycling and Disposal of Aluminum Scrap Chapter 5

NUREG-1640 5-34

References

Accomet Corporation. (n/d). “Secondary Aluminum.” http://www.accomet.com/Secondary.htm

(September 12, 2002).

The Aluminum Association, Inc. 1998. “Aluminum Recycling Casebook.” Washington, DC:

Author.

The Aluminum Association, Inc. 2001. “Aluminum Statistical Review for 2000.”

Washington, DC: Author.

The Aluminum Association, Inc. 2002. “Aluminum Statistical Review for 2001.”

Washington, DC: Author.

Anigstein, R., et al. 2001. “Technical Support Document: Potential Recycling of Scrap Metal

from Nuclear Facilities, Part I: Radiological Assessment of Exposed Individuals.” Washington,

DC: U.S. Environmental Protection Agency, Office of Radiation and Indoor Air.

http://www.epa.gov/radiation/cleanmetals/docs/tsd (August 12, 2002).

Blumenthal, D. 1990. “Is That Newfangled Cookware Safe?” FDA Consumer, 24(8), 12.

http://www.fda.gov/bbs/topics/CONSUMER/CON00036.html (October 16, 2002).

Bryan, R. H. and I. T. Dudley. 1974. “Estimated Quantities of Materials Contained in a 1000-

MW(e) PWR Power Plant,” ORNL-TM-4515. Oak Ridge, TN: Oak Ridge National Laboratory. 

Cygnet Stamping & Fabricating, Inc. (n/d). “Common Materials: 5052 Aluminum Sheet.”

http://www.cygnetstamping.com/commonMaterials/5052.html (April 2, 2003).

Department of Energy (U.S.), Office of Industrial Technologies (DOE). 1999. “Recycling of

Aluminum Dross/Saltcake,” DOE/GO-10099-730, Aluminum Project Fact Sheet. Washington,

DC: Author. http://www.oit.doe.gov/nice3/factsheets/alumitech.pdf (October 27, 2002).

Eckerman, K. F., and J. C. Ryman. 1993. “External Exposure to Radionuclides in Air, Water,

and Soil,” Federal Guidance Report No. 12, EPA 402-R-93-081. Washington, DC:

U.S. Environmental Protection Agency, Office of Radiation and Indoor Air.

Environmental Protection Agency (U.S.) (EPA). 1990. Letter from R. Shafer, Alcan Recycling,

to J. Dills, Permit Review Branch, Division of Air Quality, Kentucky Department for

Environmental Protection, enclosing report: “Compliance Emission Testing on the Melt Furnace,

Decoater, Hold Furnace, Alpur Filter, Dross Baghouse, Hot and Cold Baghouses at the Alcan

Ingot and Recycling in Berea, Kentucky.” Docket A-92-61, II-D-11.

Environmental Protection Agency (U.S.) (EPA). 1995a. "Profile of the Nonferrous Metals

Industry," EPA 310-R-95-010. Washington, DC: Author.
Chapter 5 Recycling and Disposal of Aluminum Scrap

5-35 NUREG-1640

Environmental Protection Agency (U.S.) (EPA). 1995b. “Compilation of Air Pollutant Emission

Factors,” AP-42. 5th ed. Vol. 1, “Stationary Point and Area Sources.” Washington DC: Author.

http://www.epa.gov/ttn/chief/ap42/ch12/final/c12s09.pdf (October 27, 2002).

Environmental Protection Agency (U.S.) (EPA). 1997. “Exposure Factors Handbook,”

EPA/600/P-95/002Fa. Washington, DC: Author.

Environmental Protection Agency (U.S.) (EPA). 2000. “National Emission Standards for

Hazardous Air Pollutants for Secondary Aluminum Production; Final Rule.“ Federal Register,

Vol. 65, No. 57: pp. 15689–15737. March 23, 2000.

http://www.epa.gov/fedrgstr/EPA-AIR/2000/March/Day-23/a4143.htm (June 5, 2003)

Garbay, H., and A. M. Chapuis. 1991. “Radiological Impact of Very Slightly Radioactive

Copper and Aluminum Recovered from Dismantled Nuclear Facilities,” Final Report, EUR13160-FR. Commission of the European Communities, Nuclear Sciences and Technology.

Karvelas, D., et al. 1991. "An Economic and Technical Assessment of Black-Dross- and SaltCake-Recycling Systems for Application in the Secondary Aluminum Industry," ANL/ESD-11.

Argonne, IL: Argonne National Laboratory.

Kiefer, M., et al., 1995. "Health Hazard Evaluation Report: Arkansas Aluminum Alloys Inc., Hot

Springs, Arkansas," HETA 95-0244-2550. National Institute for Occupational Health and Safety.

(NTIS No. PB96210067.)

Novelli, L. R. 1997. “The Fate of Secondary Aluminum Smelting,” Scrap, 54(6), 49–58.

Plunkert, P. A. 2002. “Aluminum.” In Minerals Yearbook—2000. U.S. Geological Survey.

http://minerals.usgs.gov/minerals/pubs/commodity/aluminum/050400.pdf (June 4, 2003).

Viland, J. S. 1990. “A Secondary’s View of Recycling.” In J. H. L. van Linden et al. (Eds.)

Second International Symposium: Recycling of Metals and Engineered Materials.

Warrendale, PA: The Minerals, Metals & Materials Society.
Chapter 6 Recycling and Disposal of Concrete Rubble

6-1 NUREG-1640

Assessments have been performed of the potential radiation doses to individuals from the recycling or

disposal of concrete rubble that could be cleared from nuclear facilities. The assessment addresses

eight scenarios that depict exposures resulting from the handling and processing of cleared concrete

rubble, transportation of the rubble, the use of recycled concrete in road construction, the landfill

disposal of concrete rubble, and the infiltration of well water by leachate from landfills containing

concrete rubble. The analysis utilizes data on concrete recycling and disposal, as currently practiced in

the United States, and on contemporary U.S. work practices and living habits.

The critical group for almost one-half of the 115 radionuclides addressed by the present analysis

consists of workers processing concrete rubble for recycling or disposal. Workers building a road with

recycled concrete constitute the critical group for most of the remaining nuclides.

Mean values of mass-based normalized EDEs to critical groups range from a high of 1,400 :Sv/y per

Bq/g (5.1 mrem/y per pCi/g) from Cf-254 to a low of 1.5e-3 :Sv/y per Bq/g (5.7e-6 mrem/y per pCi/g)

from Mn-53. The corresponding surficial EDEs are 4.9 and 5.5e-6 :Sv/y per Bq/cm2

, respectively. 

Mean values of mass-based normalized effective doses range from a high of 1,400 :Sv/y per Bq/g (5.1

mrem/y per pCi/g) from Cf-254 to a low of 1.6e-3 :Sv/y per Bq/g (5.8e-6 mrem/y per pCi/g) from Mn-53. 

The corresponding surficial effective doses are 4.9 and 5.6e-6 :Sv/y per Bq/cm2

, respectively. The

critical group for Cf-254 is the workers processing concrete rubble, while that for Mn-53 comprises

persons drinking water from wells down gradient from an industrial landfill containing cleared concrete

rubble. 

6 RECYCLING AND DISPOSAL OF CONCRETE RUBBLE

This chapter describes the radiological assessment of the recycling and/or disposal of concrete

rubble that could be cleared from NRC-licensed facilities. Similar to the assessments of scrap

metals described in Chapters 3 – 5, the models created for the present analysis are based on

realistic appraisals of the use of recycled concrete in road construction, or of disposal of the

rubble in an industrial or municipal landfill.

6.1 Introduction to Analysis

As was the case with scrap metals, the evaluation of normalized effective dose equivalents

(EDEs) and effective doses from one year of exposure to cleared concrete rubble consists of two

main parts. The first step is characterizing the flow of cleared concrete through the normal

recycling process, beginning with the generation of rubble, through processing and use in road

building, as well as disposal as an alternative to recycling. 

The second step is the development and analysis of exposure scenarios. The eight scenarios in

the concrete analysis are based on corresponding scenarios for iron and steel scrap. Essential

differences between the two sets of scenarios are discussed in Section 6.3.

6.2 Flow of Concrete Rubble

This section presents an overview of the recycling and disposal of concrete rubble in the United

States. Its aim is: (1) to serve as a source of information required for the present analysis, and
Recycling and Disposal of Concrete Rubble Chapter 6

NUREG-1640 6-2

Figure 6.1 Flow of concrete rubble

(2) to provide an overall perspective on the fate of rubble generated during the demolition of

concrete structures. It thus includes some data which are not directly utilized by the analysis. 

Figure 6.1 presents a schematic diagram of the flow of recycled and disposed concrete. As is the

case in the analysis of other cleared materials, this is a simplified idealization of the actual

process. The diagram depicts the sequence of steps that is represented by the exposure scenarios

in the present analysis. Other steps and processes are discussed in the following sections of this

chapter.

6.2.1 Sources of Material

The generators of concrete rubble addressed in this study are NRC-licensed facilities: primarily

commercial power plants, test and research reactors, and industrial nuclear facilities. As

presented in Section A.2.3.3, the reference 1,000 MWe BWR commercial nuclear power plant

contains about 355,000 t of concrete. About 73,600 t is associated with non-impacted areas of

the plant. An estimated 51.4 m3

 (123 t) of surface-contaminated concrete would be removed by

scabbling during dismantlement and decontamination. In addition, an estimated 73.3 m3

 (176 t)

would have become neutron-activated during the operation of the plant. All of this contaminated

material would be disposed of as low-level waste. The balance—approximately 281,000 t—

would be subject to clearance. 

According to Table A.10, the reference 1,000 MWe PWR nuclear power plant contains

approximately 180,000 t of concrete. About 36,900 t of concrete is associated with nonimpacted areas of the plant. The remaining concrete is associated with the reactor building,

reactor auxiliaries, fuel storage, turbine building, turbine plant equipment, and reactor plant
Chapter 6 Recycling and Disposal of Concrete Rubble

6-3 NUREG-1640

equipment. About 284 t of this material is likely to be surface-contaminated and would therefore

be removed by scabbling; an indeterminate but small additional amount would be neutronactivated. The balance—about 143,000 t—would be subject to clearance.

6.2.1.1 Mass-to-Surface Ratio

A discussion of the mass-to-surface ratio of concrete rubble cleared from commercial nuclear

power plants is presented in Section A.6.2. In the case of the PWR, data on the components

which would be subject to clearance were excerpted from Section A.6.2.1 and reproduced in

Table 6.1. The total mass of the listed components is about 96% of the estimated mass of

cleared material; data on surface areas were not available for some components. 

Table 6.1 Concrete mass-to-surface ratios for components of reference 1,000 MWe PWR

System Component Area (m2

)

a Mass (t) Ratio (g/cm2

)

Reactor building

Structural concrete 697 12,860 1,846

Cylindrical wall 5,760 20,208 351

Dome 2,787 7,348 264

Interior 4,645 13,778 297

Turbine building

Concrete fill 4,905 1,837 37

Structural concrete 4,088 11,941 292

Superstructure 2,508 2,021 81

Reactor auxiliaries Structural concrete 13,471 33,067 245

Fuel Storage Structural concrete 1,301 5,511 424

Superstructure 650 919 141

Turbine plant

equipment

Concrete fill - foundation mat 307 1,837 599

Foundation mat 307 3,674 1,198

Support 1,626 5,879 362

Intake/discharge 1,161 2,756 237

Warming line 46 129 277

Discharge tunnel 1,858 4,042 218

Discharge canal 2,323 8,267 356

De-icing pump pit structure 557 1,286 231

Total 48,999 137,358 280

a Assumes that only one side is contaminated

Comparable data are not available for the reference BWR. The mass-to-surface ratios for a

BWR were therefore assumed to be the same as those for a PWR. The distribution of mass-tothickness ratios, averaged over the total amount of concrete cleared during one year of

dismantlement activities, was created in a similar manner to that for the steel components

described in Chapter 3. The resulting distribution spans a range of 235 to 348 g/cm2, with a

mean of 281 g/cm2

.
Recycling and Disposal of Concrete Rubble Chapter 6

1

 It is assumed that concrete rubble destined for landfill disposal would also be processed to remove the rebar.

NUREG-1640 6-4

6.2.2 Transportation and Processing

Because of the large quantities of concrete rubble generated during the dismantlement of a

nuclear power plant, and the high cost of transportation relative to its intrinsic value, the material

would most likely be processed at or near the site of the plant; furthermore, the processed rubble

would most likely be utilized and/or disposed of at nearby locations. Trucks are typically used

for transportation over these relatively short distances.

Prior to use, concrete rubble must be crushed and sorted. Any steel rebar in the concrete would

be separated and sent to a ferrous metal scrap dealer.1 Prior to being crushed, the concrete is

reduced to blocks, approximately 1.5 × 1.5 × 0.8 m in size. During crushing, water is sprayed on

the concrete to suppress dust. Franklin Associates (1998) estimate that there are more than 1,000

asphalt and concrete crushing facilities in the United States. 

As described by the Turner-Fairbank Highway Research Center (TFHRC 1997):

RCM [reclaimed concrete material] is generated through the demolition of portland cement

concrete elements of roads, runways, and structures during road reconstruction, utility

excavations, or demolition operations. 

In many metropolitan areas, the RCM source is from existing portland cement concrete

curb, sidewalk and driveway sections that may or may not be lightly reinforced. The RCM

is usually removed with a backhoe or payloader and is loaded into dump trucks for removal

from the site. The RCM excavation may include 10 to 30 percent subbase soil material and

asphalt pavement. Therefore, the RCM is not pure portland cement concrete, but a mixture

of concrete, soil, and small quantities of bituminous concrete. 

The excavated concrete that will be recycled is typically hauled to a central facility for

stockpiling and processing or, in some cases (such as large reconstruction projects),

processed on site using a mobile plant. At the central processing facility, crushing,

screening, and ferrous metal recovery operations occur. Present crushing systems, with

magnetic separators, are capable of removing reinforcing steel without much difficulty.

Welded wire mesh reinforcement, however, may be difficult or impossible to remove

effectively. 

The U.S. Geological Survey (2000) has estimated that 200 million tonnes of potentially

recyclable aggregates are generated annually from the demolition of roads and buildings:

Demolished infrastructure can either be disposed in landfills or recycled. The decision is

usually made by the demolition contractor, taking into consideration regional economics,

contract terms, and legal mandates.
Chapter 6 Recycling and Disposal of Concrete Rubble

2 Gabion: A bottomless basket of wickerwork or metal iron filled with earth or stones; used in building fieldworks

or as revetments in mining (Parker 1994).

6-5 NUREG-1640

6.2.3 Use of Recycled Concrete

According to USGS 2000, about 100 Mt of concrete aggregate is recycled annually, which

represents about 5% of the 2-Gt annual aggregate market. A breakdown of the applications for

recycled aggregate is as follows:

• Road base . . . . . . . . . . . . . . . . . . . . . . . 68%

• New concrete mixes . . . . . . . . . . . . . . . . 6%

• Asphalt hot mixes . . . . . . . . . . . . . . . . . 9%

• High-value riprap . . . . . . . . . . . . . . . . . . 3%

• Low-value products (e.g., general fill) . 7%

• Other applications . . . . . . . . . . . . . . . . . 7%

It is apparent from the above tabulation that use of recycled concrete as aggregate in new

concrete mixes is limited (i.e., about 6%). TFHRC (1997) has reported that concrete

incorporating more than 10% to 20% recycled concrete as fine aggregate can have quality

problems because of the large amount of water required to maintain workability of the mix. The

report provides a list of uses for RCM that is similar to that of USGS 2000, including:

• Aggregate in cement-treated or lean concrete bases

• Concrete aggregate

• Aggregate for flowable fill

• Aggregate in asphaltic concrete

• Bulk fill on land and water

• Shoreline protection material (riprap)

• Gabion basket fill2

• Granular aggregate for base

• Trench backfill

TFHRC (1997) also reports that

. . . disposal in landfills, near the right-of-way, and in borrow pits or depleted quarries has

historically been the most common method of managing RCM. However, recycling has

become a more attractive option, particularly in aggregate-scarce areas and in large urban

areas where gathering and distribution networks for RCM have been developed.

Recycling can eliminate the costs of haulage to landfills—$0.15 per ton-mile (~$0.10 per

t-km)—and disposal—about $100 per ton (~$110/t). RCM is used as road base in 44 states

(AGC 2002).
Recycling and Disposal of Concrete Rubble Chapter 6

3

 Jim Miller, Sales & Estimating Dept., Southern Crushed Concrete Inc., private communication with William C.

Thurber, SC&A, Inc., December, 2001.

4

 William Turley, Executive Director, Construction Materials Recycling Association, private communication with

William C. Thurber, SC&A, Inc., January 7, 2002.

5

 In the present report, C&D landfills are subsumed under the more general category of industrial landfills. 

NUREG-1640 6-6

While recycled concrete is used to a limited extent as an aggregate in portland cement concrete

for highway construction, no general usage of this recycled material as an aggregate for concrete

used in building construction was identified in the course of the present analysis. A

representative of Southern Crushed Concrete Inc.—a company that recycles concrete—knew of

no use of RCM as aggregate in new concrete mixes for buildings. He believed that recycled

aggregate was not used in buildings because of structural concerns as compared to concrete with

virgin aggregate. The company had been involved in a highway project in Texas, where 30% of

the virgin aggregate was replaced with aggregate from recycled concrete.3 The view that

reclaimed concrete was not used as an aggregate in concrete used to construct buildings was

confirmed by an official of the Construction Materials Recycling Association.4

According to the Texas Department of Transportation (TxDOT 1999), one highway construction

project near Houston has used 100% recycled concrete aggregate (coarse and fine) in new

pavement concrete. Construction crews observed that the concrete was not consistent and that it

sometimes set too quickly. In spite of these concerns, pavement performance has been good.

6.2.4 Disposal

Concrete rubble that is not suitable for recycling, or that the licensee elects not to recycle, is sent

directly to a landfill. The following discussion of construction and demolition (C&D) debris is

based on Franklin Associates 1998.

While the definition of C&D debris varies from state to state, concrete is a significant component

of debris from all sources; it is the largest component of building demolition debris. The most

common management practice for C&D debris is landfilling, which may be done in C&D

landfills,5

 municipal solid waste (MSW) landfills, or at unpermitted sites. In 1996, an estimated

35% to 45% of C&D debris was placed in C&D landfills, while another 30% to 40% was

managed on site, at MSW landfills, or at unpermitted landfills. Most of the balance was

recycled. There were 1,900 active C&D landfills in the United States in 1994, with 280 in

Florida and more than 100 each in Louisiana, North Carolina, Ohio, Kentucky, Mississippi, and

South Dakota. 

State regulation of C&D landfills is highly variable. In 11 states, the C&D landfill must meet

MSW landfill requirements, while in 24 states the regulatory requirements for C&D landfills are

separate from MSW landfill requirements. In addition, eight states have separate requirements

for off-site and on-site landfills, while seven states exempt on-site C&D landfills from

regulation.
Chapter 6 Recycling and Disposal of Concrete Rubble

6-7 NUREG-1640

6.3 Concrete Recycling and Disposal Scenarios

The eight exposure scenarios included in the concrete analysis, along with the mixing factors and

environmental transport pathways included in each scenario, are listed in Table 6.2. These

scenarios were adapted from the corresponding steel scenarios described in Chapter 3. The

parameter values specific to concrete are listed in Table B.11. Only those aspects of the

scenarios that are significantly different from the corresponding steel scenarios are described in

the present section. 

Table 6.2 Scenario and exposure pathway matrix

Scenario abbreviation Scenario title MFa

Exposure

pathwaysb

Extc Inh Ing

Handling and Processing

Processing concrete Processing concrete rubble at satellite facility N 50 ! !

Transport

Truck driver Truck driver hauling concrete rubble N 51 ! !

Product Use

Road building Building road using recycled concrete N F1 ! !

Driving on road Driving on road built with recycled concrete RS F1

Landfill Disposal

Disposal–industrial Handling concrete rubble at industrial landfill IL F1 ! !

Disposal–MSW Handling concrete rubble at municipal landfill ML F1 ! !

Groundwater Contaminated by Leachate from Landfills

Leachate–industrial Leachate from industrial landfill IL !

Leachate–MSW Leachate from municipal landfill ML ! a MF = mixing factor: IL = industrial landfill, ML = municipal landfill, N = no mixing, RS = road surface (see text) (additional details

on mixing in landfills in Appendix D)

b Ext = external, Inh = inhalation, Ing = inadvertent ingestion; ingestion of drinking water

c External exposure dose factors:

50 Concrete pile

51 Concrete truck

F1 Soil contaminated to an infinite depth (Eckerman and Ryman 1993)

6.3.1 Inhalation of Dust

The exposures of construction workers to inhalation of concrete dust are governed by OSHA

standards. These standards are specified in 29 CFR 1926.55(a), which states in part: 

Exposure of employees to inhalation, ingestion, skin absorption, or contact with any

material or substance at a concentration above those specified in the "Threshold Limit

Values of Airborne Contaminants for 1970" of the American Conference of

Governmental Industrial Hygienists, shall be avoided. See Appendix A to this section.

More detailed guidance is provided in 29 CFR 1910.1000(c):
Recycling and Disposal of Concrete Rubble Chapter 6

6

 These data are from an ANSI/ANS standard for performing radiation transport calculations for nuclear reactors. 

They were adopted as fixed values in the present analysis.

7

 T. Taylor Eighmy, Director, Recycled Materials Resource Center, University of New Hampshire, private

communication with Robert Anigstein, SC&A, Inc., March 21, 2003.

NUREG-1640 6-8

6.1

"Table Z-3." An employee's exposure to any substance listed in Table Z-3, in any 8-hour

work shift of a 40-hour work week, shall not exceed the 8-hour time weighted average

[(TWA)] limit given for that substance in the table.

Table Z-3, entitled “Mineral Dusts,” includes a formula for calculating the TWA limits of dusts

containing crystalline silica, a category which includes concrete aerosols. The table presents the

limit in terms of the number of particles per unit volume, as well as in terms of mass loading

(used to model inhalation exposure in the present analysis). The latter limits are calculated as

follows:

3d = 8-h TWA level of respirable dust containing crystalline silica in the form of

quartz

= 0.14 mg/m3

%SiO2 = percentage of crystalline SiO2

= 67.5% (see below)

In the present analysis, the fraction of SiO2 in concrete is calculated from the elemental

composition of concrete listed by the American Nuclear Society (1987),6 assuming that all of the

silicon is in the form of silica. In all scenarios which include the inhalation exposure pathway, it

is assumed that dust suppression techniques (e.g., water sprays) will be employed in order that

these TWA values are not exceeded. 

The SiO2 in concrete is primarily in the form of quartz. According to Prof. T. Taylor Eighmy:

Quartz is a very common aggregate constituent, and is almost always present in naturally

derived fine aggregate sources that are mined or produced in rock crushing operations. The

nature of the parent rock will control for the presence of quartz, but since quartz is so

durable, it is usually in the surviving fraction for many parent rock systems. Quartz is also

present in quite a few coarse aggregate sources. Since coarse and fine aggregates make up

70 to 85 percent of the concrete volume, the biggest (and potentially only) source of quartz

would be the aggregates in the portland cement concrete made with portland cement alone.7

This is confirmed by Riala (n/d), who observes: Although cement does not contain quartz,

concrete dust most often contains quartz due to the quartz content of the stone aggregate. 
Chapter 6 Recycling and Disposal of Concrete Rubble

6-9 NUREG-1640

For the purpose of the present analysis, it is assumed that the silica in concrete is crystalline

quartz, and that workers’ exposures to concrete dust would be subject to the applicable OSHA

limits. 

6.3.2 Processing Concrete Rubble at Satellite Facility

The analyses of the recycling of scrap metals described in Chapters 3 – 5 assumed that the

cleared scrap would be processed at a commercial scrap yard. Because of the much greater mass

of cleared concrete, coupled with a much smaller commercial value per unit mass, transporting

the concrete over large distances would not be economically feasible. It is more likely that the

concrete would be processed at a dedicated facility at or near the site of the nuclear plant being

dismantled. Consequently, the processing scenario assumes no mixing of the cleared concrete

with other materials. 

The exposure of workers to the inhalation of concrete dust is subject to the 8-hour TWA limit of

0.14 mg/m3, derived in Section 6.3.1. Because the OSHA limits apply to any given 8-hour shift,

the long-term average dust loading would be significantly less than this limit. The 8-hour TWA

dust concentration is therefore modeled as a truncated lognormal distribution, with a range of

zero to 0.014 mg/m3

 and a mean of 0.07 mg/m3, one-half the limit. 

Exposure durations of less than eight hours per shift would permit the worker to be exposed to

proportionately higher dust concentrations. The inhalation doses are calculated to be the same as

if the worker were exposed for eight hours to the lower concentration. Doses from external

exposure and secondary ingestion are based on the time the worker actually spends on this task.

6.3.3 Transport of Concrete Rubble

The distances for shipments of concrete rubble were based on shipment distances of

“nonmetallic waste and scrap” tabulated in Bureau of the Census 1999. These distances are

represented by a normal distribution, with a mode of 231 mi (372 km), the average distance

listed by the Census Bureau, and a coefficient of variation of 10.5%, as given by the Census

Bureau. Because of the relatively short distances involved, it was assumed that the truck would

have a “day cab” (i.e., no sleeper). The driver would be exposed to inhalation of dust during

loading and unloading, as well as to the inadvertent ingestion of settled particulates. The 8-hour

TWA dust concentration is based on the same distribution as is used in the concrete processing

scenario described in Section 6.3.2. Since the actual exposure duration is assumed to be 15 – 30

minutes per trip, the actual dust concentration during the loading and unloading could be much

greater than the 8-hour TWA concentration. However, they would not be higher than the dust

concentrations that were modeled for the loading and unloading of a truck transporting steel slag,

discussed in Chapter 3.

6.3.4 Landfill Disposal Workers

The inhalation exposures of landfill disposal workers are also subject to the OSHA limits on

crystalline silica. However, since the workers handle materials other than the cleared concrete,
Recycling and Disposal of Concrete Rubble Chapter 6

8

 The annual flow of waste to various landfills is discussed in Section D.2.1.1.

NUREG-1640 6-10

the percentage of crystalline SiO2 in Equation 6.1 is adjusted by multiplying the silica in

concrete (67.5%) by the amount of cleared concrete (in a given realization) as a fraction of the

total waste stream to a given landfill.8

 The distribution representing the 8-hour TWA dust

concentration is adjusted in the same manner.

6.3.5 Concrete Road Scenarios

In both scenarios involving roads built with recycled concrete—“building road using recycled

concrete” and “driving on road built with recycled concrete”—the fraction of RCM used in the

asphaltic concrete of the road surface has a range of 10% to 80%, with a most probable value of

24%. As in the corresponding scenarios in the steel analysis, aggregate is assumed to constitute

80% of the pavement. The low end of the distribution is based on the observation of TFHRC

(1997), cited in Section 6.2.3, that concrete incorporating more than 10% to 20% recycled

concrete as fine aggregate can have quality problems. The maximum value is based on the use

of 100% RCM as aggregate, as cited by TxDOT 1997, while the probable value was based on the

experience of Southern Crushed Concrete, which used RCM as 30% of the aggregate (0.3 × 0.8

= 0.24).

The inhalation exposures of the road construction workers are modeled in the same way as those

of the concrete processing workers, described in Section 6.3.2. 

6.3.6 Scenario Timing

The following basic assumptions are adopted to estimate the timing for the scenarios:

• Processing of cleared rubble occurs between two and 30 days following clearance.

• Transportation to a road-building site or a landfill takes place one to 30 days after

processing.

• Disposal activities take place between one and seven days after the concrete arrives at the

landfill.

• Road-building activities occur between one and 30 days after the concrete arrives on site.

• Use of the roadway begins one day after the road is constructed.

6.4 Dose Assessments of Recycling and Disposal of Concrete Rubble

As discussed in previous sections of this chapter, the radiological assessment of the clearance of

concrete rubble from NRC-licensed nuclear facilities evaluates the radiation exposures of
Chapter 6 Recycling and Disposal of Concrete Rubble

9

 As discussed in Chapter 1, the group which receives the highest mean normalized EDE from a given radionuclide

is defined as the EDE-critical group for that nuclide. 

6-11 NUREG-1640

Figure 6.2 Scenarios giving rise to EDE-critical groups for concrete

individual members of various groups to each of 115 radionuclides and their progenies in eight

exposure scenarios. 

6.4.1 Calculation of Effective Dose Equivalents (EDEs)

The groups described by four of these scenarios receive the highest mean normalized EDEs from

one year of exposure to cleared concrete rubble from one or more nuclides. One of these groups,

workers processing concrete rubble for recycling or disposal, constitutes the EDE-critical group

for 52 nuclides.9

 Table 6.5 lists the mean and the 5th, 50th, and 95th percentile mass-based

normalized EDEs from each radionuclide to its respective critical group, while Table 6.6 lists the

corresponding surficial EDEs. Figure 6.2 lists the scenarios describing the EDE-critical groups

and displays the number of radionuclides for which each scenario constitutes the critical group. 

The mean and the 5th, 50th, 90th, and 95th percentile normalized EDEs from all 115 nuclides

from all eight scenarios are tabulated in Appendix I-1.

In the case of the 11 radionuclides listed in Table 6.3, the mean normalized EDE in the critical

group was higher than the 90th percentile EDE. The critical group for each of these nuclides

comprises persons drinking water from wells down gradient from an industrial or MSW landfill

containing cleared concrete rubble. The group with the highest EDE for which the mean does

not exceed the 90th percentile might be considered as the alternate critical group for that nuclide. 

These potential alternate critical groups are listed in Table 6.3.
Recycling and Disposal of Concrete Rubble Chapter 6

NUREG-1640 6-12

Table 6.3 Normalized mass-based EDE from selected nuclides (:Sv/y per Bq/g)

Nuclidea Critical group Potential alternate critical groupb

Mean 90th %-ile Scenario Mean 90th %-ile Scenario

C-14 1.2e-01 0.0e+00 Leachate–industrial 7.3e-03 1.3e-02 Processing concrete

Mn-53 1.5e-03 0.0e+00 Leachate–industrial 3.9e-04 6.8e-04 Processing concrete

Sr-90 1.5e+00 0.0e+00 Leachate–industrial 9.1e-01 1.4e+00 Processing concrete

Mo-93 1.7e-01 0.0e+00 Leachate–industrial 1.4e-02 2.3e-02 Road building

Cs-135 2.6e-02 0.0e+00 Leachate–MSW 2.5e-02 4.4e-02 Processing concrete

U-233 3.2e+01 0.0e+00 Leachate–MSW 7.1e+00 9.9e+00 Processing concrete

U-234 2.3e+01 0.0e+00 Leachate–MSW 7.0e+00 9.7e+00 Processing concrete

U-235 3.3e+01 0.0e+00 Leachate–MSW 1.8e+01 2.3e+01 Processing concrete

U-236 2.2e+01 0.0e+00 Leachate–MSW 6.6e+00 9.2e+00 Processing concrete

U-238 2.1e+01 0.0e+00 Leachate–MSW 8.6e+00 1.1e+01 Processing concrete

Np-237 1.1e+03 2.0e+02 Leachate–industrial 5.6e+01 7.3e+01 Processing concrete

a

 Nuclides from which mean normalized EDE exceeds 90th percentile EDE

b

 Group with maximum mean EDE which does not exceed 90th percentile EDE to that group

6.4.2 Calculation of Effective Doses

The groups described by five of the exposure scenarios receive the highest mean normalized

effective doses from one year of exposure to cleared concrete rubble from one or more nuclides. 

One group, workers processing concrete rubble for recycling or disposal, constitutes the effective

dose-critical group for 56 nuclides. Table 6.7 lists the mean and the 5th, 50th, and 95th

percentile mass-based normalized effective doses from each radionuclide to its respective critical

group, while Table 6.8 lists the corresponding surficial effective doses. Figure 6.3 lists the

scenarios describing the effective dose-critical groups and displays the number of radionuclides

for which each scenario constitutes the critical group. The mean and the 5th, 50th, 90th, and

95th percentile normalized effective doses from all 115 nuclides from all eight scenarios are

tabulated in Appendix I-2.

In the case of the 12 radionuclides listed in Table 6.4, the mean normalized effective dose in the

critical group was higher than the 90th percentile effective dose. The critical group for each of

these nuclides again comprises persons drinking water from wells down gradient from an

industrial or MSW landfill containing cleared concrete rubble. The potential alternate critical

groups are listed in Table 6.4.
Chapter 6 Recycling and Disposal of Concrete Rubble

6-13 NUREG-1640

Figure 6.3 Scenarios giving rise to effective dose-critical groups for concrete

Table 6.4 Normalized mass-based effective doses from selected nuclides (:Sv/y per Bq/g)

Nuclidea Critical group Potential alternate critical groupb

Mean 90th %-ile Scenario Mean 90th %-ile Scenario

C-14 1.2e-01 0.0e+00 Leachate–industrial 7.5e-03 1.3e-02 Processing concrete

Mn-53 1.6e-03 0.0e+00 Leachate–industrial 3.8e-04 6.8e-04 Processing concrete

Sr-90 1.1e+00 0.0e+00 Leachate–industrial 9.7e-01 1.6e+00 Road building

Mo-93 9.0e-01 0.0e+00 Leachate–industrial 3.9e-02 6.5e-02 Processing concrete

Cs-135 2.7e-02 0.0e+00 Leachate–MSW 2.6e-02 4.6e-02 Processing concrete

U-232 2.9e+01 0.0e+00 Leachate–MSW 2.0e+01 3.5e+01 Driving on road

U-233 2.0e+01 0.0e+00 Leachate–MSW 1.8e+00 2.5e+00 Processing concrete

U-234 1.5e+01 0.0e+00 Leachate–MSW 1.8e+00 2.4e+00 Processing concrete

U-235 1.7e+01 0.0e+00 Leachate–MSW 1.3e+01 2.2e+01 Road building

U-236 1.4e+01 0.0e+00 Leachate–MSW 1.6e+00 2.3e+00 Processing concrete

U-238 1.4e+01 0.0e+00 Leachate–MSW 3.9e+00 4.9e+00 Processing concrete

Np-237 9.9e+01 1.8e+01 Leachate–industrial 2.1e+01 2.7e+01 Processing concrete

a Nuclides from which mean normalized effective dose exceeds 90th percentile effective dose

b Group with maximum mean effective dose which does not exceed 90th percentile effective dose to that group
Recycling and Disposal of Concrete Rubble Chapter 6

NUREG-1640 6-14

Table 6.5 Normalized mass-based effective dose equivalents to critical groups for concrete Radionuclide

:Sv/y per Bq/g mrem/y per pCi/g

Scenario

Mean

Percentilea

Mean

Percentilea

5th 50th 95th 5th 50th 95th

H-3 6.6e-02 0.0e+00 4.4e-05 2.9e-01 2.4e-04 0.0e+00 1.6e-07 1.1e-03 Leachate-industrial

C-14 1.2e-01 0.0e+00 0.0e+00 2.8e-01 4.3e-04 0.0e+00 0.0e+00 1.0e-03 Leachate-industrial

Na-22 2.4e+02 1.2e+02 2.1e+02 4.6e+02 8.8e-01 4.3e-01 7.7e-01 1.7e+00 Road building

P-32 1.1e-01 4.4e-02 9.5e-02 2.0e-01 3.9e-04 1.6e-04 3.5e-04 7.5e-04 Processing concrete

S-35 1.6e-03 3.8e-04 1.6e-03 2.9e-03 5.9e-06 1.4e-06 5.8e-06 1.1e-05 Processing concrete

Cl-36 1.3e+00 0.0e+00 0.0e+00 6.2e+00 4.8e-03 0.0e+00 0.0e+00 2.3e-02 Leachate-industrial

K-40 1.9e+01 9.1e+00 1.6e+01 3.6e+01 6.9e-02 3.4e-02 6.1e-02 1.3e-01 Road building

Ca-41 7.2e-01 0.0e+00 0.0e+00 3.7e+00 2.7e-03 0.0e+00 0.0e+00 1.4e-02 Leachate-industrial

Ca-45 1.1e-02 2.0e-03 1.1e-02 2.1e-02 4.1e-05 7.3e-06 4.0e-05 7.7e-05 Processing concrete

Sc-46 1.7e+02 7.5e+01 1.4e+02 3.3e+02 6.2e-01 2.8e-01 5.3e-01 1.2e+00 Road building

Cr-51 1.8e+00 9.3e-01 1.7e+00 2.8e+00 6.5e-03 3.4e-03 6.2e-03 1.0e-02 Processing concrete

Mn-53 1.5e-03 0.0e+00 0.0e+00 0.0e+00 5.7e-06 0.0e+00 0.0e+00 0.0e+00 Leachate-industrial

Mn-54 8.5e+01 4.1e+01 7.4e+01 1.6e+02 3.1e-01 1.5e-01 2.7e-01 6.0e-01 Road building

Fe-55 2.1e-03 3.1e-04 2.1e-03 4.1e-03 7.9e-06 1.1e-06 7.8e-06 1.5e-05 Processing concrete

Fe-59 8.8e+01 5.1e+01 8.6e+01 1.3e+02 3.3e-01 1.9e-01 3.2e-01 5.0e-01 Processing concrete

Co-56 3.0e+02 1.4e+02 2.6e+02 6.1e+02 1.1e+00 5.0e-01 9.7e-01 2.2e+00 Road building

Co-57 8.1e+00 4.0e+00 7.1e+00 1.6e+01 3.0e-02 1.5e-02 2.6e-02 5.8e-02 Road building

Co-58 7.5e+01 4.5e+01 7.4e+01 1.1e+02 2.8e-01 1.7e-01 2.7e-01 4.1e-01 Processing concrete

Co-60 2.9e+02 1.4e+02 2.5e+02 5.5e+02 1.1e+00 5.2e-01 9.3e-01 2.0e+00 Road building

Ni-59 2.1e-03 1.2e-03 2.1e-03 3.1e-03 7.9e-06 4.5e-06 7.8e-06 1.2e-05 Processing concrete

Ni-63 2.1e-03 3.2e-04 2.1e-03 4.0e-03 7.7e-06 1.2e-06 7.6e-06 1.5e-05 Processing concrete

Zn-65 5.9e+01 2.9e+01 5.2e+01 1.1e+02 2.2e-01 1.1e-01 1.9e-01 4.2e-01 Road building

As-73 1.2e-01 5.5e-02 1.1e-01 2.5e-01 4.6e-04 2.0e-04 3.9e-04 9.1e-04 Road building

Se-75 2.8e+01 1.3e+01 2.5e+01 5.5e+01 1.1e-01 5.0e-02 9.2e-02 2.0e-01 Road building

Sr-85 3.6e+01 2.1e+01 3.5e+01 5.3e+01 1.3e-01 7.8e-02 1.3e-01 2.0e-01 Processing concrete

Sr-89 1.4e-01 8.3e-02 1.4e-01 2.1e-01 5.2e-04 3.1e-04 5.0e-04 7.7e-04 Processing concrete

Sr-90 1.5e+00 0.0e+00 0.0e+00 2.7e-06 5.4e-03 0.0e+00 0.0e+00 9.9e-09 Leachate-industrial

Y-91 4.3e-01 2.6e-01 4.2e-01 6.4e-01 1.6e-03 9.6e-04 1.6e-03 2.4e-03 Processing concrete

Zr-93 9.4e-03 3.9e-03 9.3e-03 1.5e-02 3.5e-05 1.4e-05 3.4e-05 5.6e-05 Processing concrete

Zr-95 8.6e+01 4.2e+01 7.5e+01 1.6e+02 3.2e-01 1.6e-01 2.8e-01 6.1e-01 Road building

Nb-93m 3.8e-03 2.0e-03 3.8e-03 5.8e-03 1.4e-05 7.6e-06 1.4e-05 2.1e-05 Processing concrete

Nb-94 1.7e+02 8.5e+01 1.5e+02 3.3e+02 6.4e-01 3.1e-01 5.6e-01 1.2e+00 Road building

Nb-95 5.1e+01 2.8e+01 4.9e+01 8.0e+01 1.9e-01 1.0e-01 1.8e-01 2.9e-01 Processing concrete

Mo-93 1.7e-01 0.0e+00 0.0e+00 2.4e-01 6.4e-04 0.0e+00 0.0e+00 8.8e-04 Leachate-industrial

Tc-97 7.1e-01 0.0e+00 0.0e+00 3.3e+00 2.6e-03 0.0e+00 0.0e+00 1.2e-02 Leachate-industrial

Tc-97m 2.7e-02 1.3e-02 2.4e-02 5.4e-02 1.0e-04 4.6e-05 8.8e-05 2.0e-04 Road building

Tc-99 6.1e+00 0.0e+00 0.0e+00 2.8e+01 2.2e-02 0.0e+00 0.0e+00 1.1e-01 Leachate-industrial

Ru-103 3.2e+01 1.8e+01 3.2e+01 5.0e+01 1.2e-01 6.8e-02 1.2e-01 1.9e-01 Processing concrete

Ru-106 2.2e+01 1.1e+01 1.9e+01 4.1e+01 8.0e-02 3.9e-02 7.0e-02 1.5e-01 Road building

a

 5th percentile to 95th percentile = 90% confidence interval
Chapter 6 Recycling and Disposal of Concrete Rubble

Table 6.5 Normalized mass-based effective dose equivalents to critical groups for concrete Radionuclide

:Sv/y per Bq/g mrem/y per pCi/g

Scenario

Mean

Percentilea

Mean

Percentilea

5th 50th 95th 5th 50th 95th

6-15 NUREG-1640

Ag-108m 1.7e+02 8.4e+01 1.5e+02 3.3e+02 6.4e-01 3.1e-01 5.6e-01 1.2e+00 Road building

Ag-110m 2.8e+02 1.3e+02 2.4e+02 5.3e+02 1.0e+00 5.0e-01 8.9e-01 2.0e+00 Road building

Cd-109 4.8e-01 2.4e-01 4.2e-01 9.0e-01 1.8e-03 8.7e-04 1.5e-03 3.3e-03 Road building

Sn-113 2.1e+01 9.8e+00 1.8e+01 4.1e+01 7.7e-02 3.6e-02 6.7e-02 1.5e-01 Road building

Sb-124 1.5e+02 8.6e+01 1.4e+02 2.2e+02 5.4e-01 3.2e-01 5.3e-01 8.0e-01 Processing concrete

Sb-125 4.3e+01 2.1e+01 3.7e+01 8.2e+01 1.6e-01 7.7e-02 1.4e-01 3.0e-01 Road building

Te-123m 9.0e+00 4.2e+00 7.9e+00 1.8e+01 3.3e-02 1.6e-02 2.9e-02 6.5e-02 Road building

Te-127m 4.8e-01 2.3e-01 4.2e-01 9.4e-01 1.8e-03 8.4e-04 1.6e-03 3.5e-03 Road building

I-125 2.5e-01 1.0e-01 2.1e-01 5.1e-01 9.1e-04 3.8e-04 7.9e-04 1.9e-03 Road building

I-129 2.9e+02 0.0e+00 0.0e+00 1.3e+03 1.1e+00 0.0e+00 0.0e+00 4.8e+00 Leachate-industrial

I-131 1.0e+01 2.3e+00 7.7e+00 2.5e+01 3.7e-02 8.6e-03 2.9e-02 9.4e-02 Processing concrete

Cs-134 1.6e+02 8.0e+01 1.4e+02 3.1e+02 6.1e-01 3.0e-01 5.3e-01 1.2e+00 Road building

Cs-135 2.6e-02 0.0e+00 0.0e+00 0.0e+00 9.5e-05 0.0e+00 0.0e+00 0.0e+00 Leachate-MSW

Cs-137 6.1e+01 3.0e+01 5.3e+01 1.2e+02 2.3e-01 1.1e-01 2.0e-01 4.3e-01 Road building

Ba-133 3.5e+01 1.7e+01 3.1e+01 6.7e+01 1.3e-01 6.4e-02 1.1e-01 2.5e-01 Road building

Ce-139 9.4e+00 4.5e+00 8.2e+00 1.8e+01 3.5e-02 1.7e-02 3.0e-02 6.8e-02 Road building

Ce-141 3.2e+00 1.8e+00 3.1e+00 5.1e+00 1.2e-02 6.5e-03 1.1e-02 1.9e-02 Processing concrete

Ce-144 5.3e+00 2.6e+00 4.6e+00 1.0e+01 1.9e-02 9.5e-03 1.7e-02 3.7e-02 Road building

Pm-147 5.9e-03 2.6e-03 5.8e-03 9.5e-03 2.2e-05 9.5e-06 2.2e-05 3.5e-05 Processing concrete

Sm-151 2.7e-03 1.3e-03 2.7e-03 4.2e-03 9.9e-06 4.7e-06 9.9e-06 1.5e-05 Processing concrete

Eu-152 1.2e+02 6.1e+01 1.1e+02 2.4e+02 4.6e-01 2.3e-01 4.0e-01 8.8e-01 Road building

Eu-154 1.4e+02 6.7e+01 1.2e+02 2.6e+02 5.0e-01 2.5e-01 4.4e-01 9.6e-01 Road building

Eu-155 3.2e+00 1.6e+00 2.8e+00 6.1e+00 1.2e-02 5.8e-03 1.0e-02 2.3e-02 Road building

Gd-153 3.9e+00 1.9e+00 3.4e+00 7.5e+00 1.5e-02 7.1e-03 1.3e-02 2.8e-02 Road building

Tb-160 8.8e+01 5.2e+01 8.6e+01 1.3e+02 3.2e-01 1.9e-01 3.2e-01 4.8e-01 Processing concrete

Tm-170 2.3e-01 1.1e-01 2.0e-01 4.4e-01 8.4e-04 4.0e-04 7.3e-04 1.6e-03 Road building

Tm-171 2.0e-02 1.0e-02 1.8e-02 3.9e-02 7.5e-05 3.7e-05 6.6e-05 1.4e-04 Road building

Ta-182 1.1e+02 5.3e+01 9.8e+01 2.2e+02 4.2e-01 2.0e-01 3.6e-01 8.1e-01 Road building

W-181 1.1e+00 5.2e-01 9.6e-01 2.1e+00 4.1e-03 1.9e-03 3.5e-03 7.9e-03 Road building

W-185 9.7e-03 4.7e-03 9.5e-03 1.5e-02 3.6e-05 1.8e-05 3.5e-05 5.6e-05 Processing concrete

Os-185 5.6e+01 2.6e+01 4.9e+01 1.1e+02 2.1e-01 9.6e-02 1.8e-01 4.1e-01 Road building

Ir-192 5.8e+01 2.6e+01 5.1e+01 1.2e+02 2.2e-01 9.5e-02 1.9e-01 4.3e-01 Road building

Tl-204 7.8e-02 3.9e-02 6.8e-02 1.5e-01 2.9e-04 1.4e-04 2.5e-04 5.5e-04 Road building

Pb-210 2.5e+01 3.3e+00 2.5e+01 5.0e+01 9.4e-02 1.2e-02 9.3e-02 1.8e-01 Processing concrete

Bi-207 1.7e+02 8.2e+01 1.5e+02 3.2e+02 6.2e-01 3.0e-01 5.4e-01 1.2e+00 Road building

Po-210 6.3e+00 9.1e-01 6.1e+00 1.2e+01 2.3e-02 3.4e-03 2.3e-02 4.5e-02 Processing concrete

Ra-226 2.0e+02 1.0e+02 1.8e+02 3.9e+02 7.5e-01 3.7e-01 6.6e-01 1.4e+00 Road building

Ra-228 1.2e+02 5.7e+01 1.0e+02 2.2e+02 4.3e-01 2.1e-01 3.8e-01 8.2e-01 Road building

a 5th percentile to 95th percentile = 90% confidence interval
Recycling and Disposal of Concrete Rubble Chapter 6

Table 6.5 Normalized mass-based effective dose equivalents to critical groups for concrete Radionuclide

:Sv/y per Bq/g mrem/y per pCi/g

Scenario

Mean

Percentilea

Mean

Percentilea

5th 50th 95th 5th 50th 95th

NUREG-1640 6-16

Ac-227 1.4e+02 8.3e+01 1.4e+02 2.0e+02 5.2e-01 3.1e-01 5.1e-01 7.4e-01 Processing concrete

Th-228 1.8e+02 9.1e+01 1.6e+02 3.5e+02 6.8e-01 3.3e-01 5.9e-01 1.3e+00 Road building

Th-229 1.3e+02 8.6e+01 1.3e+02 1.9e+02 4.9e-01 3.2e-01 4.8e-01 7.2e-01 Processing concrete

Th-230 1.8e+01 9.7e+00 1.7e+01 2.9e+01 6.6e-02 3.6e-02 6.2e-02 1.1e-01 Truck driver

Th-232 8.9e+01 4.9e+01 8.5e+01 1.5e+02 3.3e-01 1.8e-01 3.1e-01 5.4e-01 Truck driver

Pa-231 9.7e+01 5.2e+01 9.5e+01 1.5e+02 3.6e-01 1.9e-01 3.5e-01 5.4e-01 Processing concrete

U-232 3.7e+01 2.0e+01 3.5e+01 6.0e+01 1.4e-01 7.6e-02 1.3e-01 2.2e-01 Truck driver

U-233 3.2e+01 0.0e+00 0.0e+00 0.0e+00 1.2e-01 0.0e+00 0.0e+00 0.0e+00 Leachate-MSW

U-234 2.3e+01 0.0e+00 0.0e+00 0.0e+00 8.5e-02 0.0e+00 0.0e+00 0.0e+00 Leachate-MSW

U-235 3.3e+01 0.0e+00 0.0e+00 0.0e+00 1.2e-01 0.0e+00 0.0e+00 0.0e+00 Leachate-MSW

U-236 2.1e+01 0.0e+00 0.0e+00 0.0e+00 7.9e-02 0.0e+00 0.0e+00 0.0e+00 Leachate-MSW

U-238 2.1e+01 0.0e+00 0.0e+00 0.0e+00 7.9e-02 0.0e+00 0.0e+00 0.0e+00 Leachate-MSW

Np-237 1.1e+03 0.0e+00 0.0e+00 2.4e+03 4.0e+00 0.0e+00 0.0e+00 8.7e+00 Leachate-industrial

Pu-236 1.0e+01 5.5e+00 1.0e+01 1.6e+01 3.8e-02 2.0e-02 3.8e-02 5.8e-02 Processing concrete

Pu-238 2.9e+01 1.5e+01 2.8e+01 4.3e+01 1.1e-01 5.5e-02 1.0e-01 1.6e-01 Processing concrete

Pu-239 3.1e+01 1.6e+01 3.1e+01 4.8e+01 1.2e-01 6.1e-02 1.1e-01 1.8e-01 Processing concrete

Pu-240 3.1e+01 1.6e+01 3.1e+01 4.8e+01 1.2e-01 6.1e-02 1.1e-01 1.8e-01 Processing concrete

Pu-241 6.1e-01 3.2e-01 6.0e-01 9.2e-01 2.2e-03 1.2e-03 2.2e-03 3.4e-03 Processing concrete

Pu-242 3.0e+01 1.6e+01 3.0e+01 4.5e+01 1.1e-01 5.8e-02 1.1e-01 1.7e-01 Processing concrete

Pu-244 5.8e+01 3.9e+01 5.8e+01 7.9e+01 2.2e-01 1.5e-01 2.1e-01 2.9e-01 Processing concrete

Am-241 3.3e+01 1.8e+01 3.2e+01 5.0e+01 1.2e-01 6.5e-02 1.2e-01 1.8e-01 Processing concrete

Am-242m 3.3e+01 1.8e+01 3.3e+01 5.0e+01 1.2e-01 6.6e-02 1.2e-01 1.8e-01 Processing concrete

Am-243 4.5e+01 2.9e+01 4.5e+01 6.3e+01 1.7e-01 1.1e-01 1.7e-01 2.3e-01 Processing concrete

Cm-242 1.1e+00 6.0e-01 1.1e+00 1.7e+00 4.1e-03 2.2e-03 4.0e-03 6.2e-03 Processing concrete

Cm-243 3.0e+01 1.9e+01 3.0e+01 4.3e+01 1.1e-01 7.1e-02 1.1e-01 1.6e-01 Processing concrete

Cm-244 1.8e+01 9.5e+00 1.8e+01 2.7e+01 6.7e-02 3.5e-02 6.6e-02 1.0e-01 Processing concrete

Cm-245 3.8e+01 2.2e+01 3.8e+01 5.6e+01 1.4e-01 8.3e-02 1.4e-01 2.1e-01 Processing concrete

Cm-246 3.3e+01 1.7e+01 3.2e+01 5.0e+01 1.2e-01 6.4e-02 1.2e-01 1.8e-01 Processing concrete

Cm-247 5.7e+01 3.9e+01 5.7e+01 7.7e+01 2.1e-01 1.4e-01 2.1e-01 2.9e-01 Processing concrete

Cm-248 1.2e+02 6.3e+01 1.2e+02 1.8e+02 4.5e-01 2.3e-01 4.4e-01 6.8e-01 Processing concrete

Bk-249 1.0e-01 5.5e-02 1.0e-01 1.6e-01 3.9e-04 2.0e-04 3.8e-04 5.9e-04 Processing concrete

Cf-248 3.3e+00 1.8e+00 3.3e+00 5.0e+00 1.2e-02 6.7e-03 1.2e-02 1.9e-02 Processing concrete

Cf-249 6.0e+01 3.9e+01 5.9e+01 8.2e+01 2.2e-01 1.4e-01 2.2e-01 3.0e-01 Processing concrete

Cf-250 1.6e+01 8.2e+00 1.6e+01 2.5e+01 6.1e-02 3.1e-02 6.0e-02 9.3e-02 Processing concrete

Cf-251 4.1e+01 2.3e+01 4.1e+01 6.0e+01 1.5e-01 8.4e-02 1.5e-01 2.2e-01 Processing concrete

Cf-252 1.1e+01 5.8e+00 1.0e+01 1.6e+01 3.9e-02 2.1e-02 3.9e-02 5.9e-02 Processing concrete

Cf-254 1.4e+03 8.1e+02 1.3e+03 2.0e+03 5.1e+00 3.0e+00 5.0e+00 7.5e+00 Processing concrete

Es-254 9.2e+01 4.5e+01 8.0e+01 1.8e+02 3.4e-01 1.7e-01 3.0e-01 6.5e-01 Road building

a 5th percentile to 95th percentile = 90% confidence interval
Chapter 6 Recycling and Disposal of Concrete Rubble

6-17 NUREG-1640

Table 6.6 Normalized surficial effective dose equivalents to critical groups for concrete

Radionuclide

:Sv/y per Bq/cm2 mrem/y per pCi/cm2

Mean

Percentilea

Mean

Percentilea

Scenario

5th 50th 95th 5th 50th 95th

H-3 2.4e-04 0.0e+00 1.6e-07 1.0e-03 8.7e-07 0.0e+00 5.8e-10 3.8e-06 Leachate-industrial

C-14 4.1e-04 0.0e+00 0.0e+00 9.8e-04 1.5e-06 0.0e+00 0.0e+00 3.6e-06 Leachate-industrial

Na-22 8.5e-01 4.1e-01 7.4e-01 1.6e+00 3.1e-03 1.5e-03 2.7e-03 6.0e-03 Road building

P-32 3.8e-04 1.6e-04 3.4e-04 7.2e-04 1.4e-06 5.8e-07 1.3e-06 2.7e-06 Processing concrete

S-35 5.7e-06 1.4e-06 5.6e-06 1.0e-05 2.1e-08 5.0e-09 2.1e-08 3.9e-08 Processing concrete

Cl-36 4.7e-03 0.0e+00 0.0e+00 2.2e-02 1.7e-05 0.0e+00 0.0e+00 8.2e-05 Leachate-industrial

K-40 6.7e-02 3.3e-02 5.8e-02 1.3e-01 2.5e-04 1.2e-04 2.2e-04 4.7e-04 Road building

Ca-41 2.6e-03 0.0e+00 0.0e+00 1.3e-02 9.5e-06 0.0e+00 0.0e+00 4.9e-05 Leachate-industrial

Ca-45 3.9e-05 7.0e-06 3.9e-05 7.5e-05 1.5e-07 2.6e-08 1.4e-07 2.8e-07 Processing concrete

Sc-46 5.9e-01 2.7e-01 5.2e-01 1.2e+00 2.2e-03 9.9e-04 1.9e-03 4.4e-03 Road building

Cr-51 6.3e-03 3.3e-03 6.0e-03 1.0e-02 2.3e-05 1.2e-05 2.2e-05 3.8e-05 Processing concrete

Mn-53 5.5e-06 0.0e+00 0.0e+00 0.0e+00 2.0e-08 0.0e+00 0.0e+00 0.0e+00 Leachate-industrial

Mn-54 3.0e-01 1.5e-01 2.6e-01 5.8e-01 1.1e-03 5.4e-04 9.8e-04 2.2e-03 Road building

Fe-55 7.6e-06 1.1e-06 7.5e-06 1.5e-05 2.8e-08 4.0e-09 2.8e-08 5.5e-08 Processing concrete

Fe-59 3.1e-01 1.8e-01 3.1e-01 4.8e-01 1.2e-03 6.7e-04 1.1e-03 1.8e-03 Processing concrete

Co-56 1.1e+00 4.8e-01 9.4e-01 2.1e+00 4.0e-03 1.8e-03 3.5e-03 8.0e-03 Road building

Co-57 2.9e-02 1.4e-02 2.5e-02 5.6e-02 1.1e-04 5.2e-05 9.3e-05 2.1e-04 Road building

Co-58 2.7e-01 1.6e-01 2.6e-01 4.0e-01 9.9e-04 5.9e-04 9.7e-04 1.5e-03 Processing concrete

Co-60 1.0e+00 5.0e-01 8.9e-01 2.0e+00 3.8e-03 1.8e-03 3.3e-03 7.3e-03 Road building

Ni-59 7.6e-06 4.3e-06 7.5e-06 1.1e-05 2.8e-08 1.6e-08 2.8e-08 4.2e-08 Processing concrete

Ni-63 7.4e-06 1.1e-06 7.3e-06 1.4e-05 2.7e-08 4.2e-09 2.7e-08 5.3e-08 Processing concrete

Zn-65 2.1e-01 1.0e-01 1.8e-01 4.1e-01 7.8e-04 3.8e-04 6.8e-04 1.5e-03 Road building

As-73 4.4e-04 2.0e-04 3.8e-04 8.7e-04 1.6e-06 7.3e-07 1.4e-06 3.2e-06 Road building

Se-75 1.0e-01 4.8e-02 8.9e-02 2.0e-01 3.8e-04 1.8e-04 3.3e-04 7.3e-04 Road building

Sr-85 1.3e-01 7.5e-02 1.3e-01 1.9e-01 4.7e-04 2.8e-04 4.6e-04 7.1e-04 Processing concrete

Sr-89 5.0e-04 2.9e-04 4.9e-04 7.5e-04 1.8e-06 1.1e-06 1.8e-06 2.8e-06 Processing concrete

Sr-90 5.2e-03 0.0e+00 0.0e+00 9.4e-09 1.9e-05 0.0e+00 0.0e+00 3.5e-11 Leachate-industrial

Y-91 1.5e-03 9.2e-04 1.5e-03 2.3e-03 5.7e-06 3.4e-06 5.6e-06 8.5e-06 Processing concrete

Zr-93 3.3e-05 1.4e-05 3.3e-05 5.4e-05 1.2e-07 5.1e-08 1.2e-07 2.0e-07 Processing concrete

Zr-95 3.1e-01 1.5e-01 2.7e-01 5.9e-01 1.1e-03 5.5e-04 9.9e-04 2.2e-03 Road building

Nb-93m 1.4e-05 7.3e-06 1.4e-05 2.1e-05 5.1e-08 2.7e-08 5.0e-08 7.7e-08 Processing concrete

Nb-94 6.2e-01 3.0e-01 5.4e-01 1.2e+00 2.3e-03 1.1e-03 2.0e-03 4.4e-03 Road building

Nb-95 1.8e-01 1.0e-01 1.8e-01 2.9e-01 6.7e-04 3.7e-04 6.5e-04 1.1e-03 Processing concrete

Mo-93 6.1e-04 0.0e+00 0.0e+00 8.4e-04 2.3e-06 0.0e+00 0.0e+00 3.1e-06 Leachate-industrial

Tc-97 2.5e-03 0.0e+00 0.0e+00 1.2e-02 9.4e-06 0.0e+00 0.0e+00 4.4e-05 Leachate-industrial

Tc-97m 9.7e-05 4.5e-05 8.5e-05 1.9e-04 3.6e-07 1.7e-07 3.1e-07 7.0e-07 Road building

Tc-99 2.2e-02 0.0e+00 0.0e+00 1.0e-01 8.0e-05 0.0e+00 0.0e+00 3.8e-04 Leachate-industrial

Ru-103 1.2e-01 6.5e-02 1.1e-01 1.8e-01 4.3e-04 2.4e-04 4.2e-04 6.7e-04 Processing concrete

Ru-106 7.7e-02 3.7e-02 6.7e-02 1.5e-01 2.8e-04 1.4e-04 2.5e-04 5.5e-04 Road building

a 5th percentile to 95th percentile = 90% confidence interval
Recycling and Disposal of Concrete Rubble Chapter 6

Table 6.6 Normalized surficial effective dose equivalents to critical groups for concrete

Radionuclide

:Sv/y per Bq/cm2 mrem/y per pCi/cm2

Mean

Percentilea

Mean

Percentilea

Scenario

5th 50th 95th 5th 50th 95th

NUREG-1640 6-18

Ag-108m 6.2e-01 3.0e-01 5.4e-01 1.2e+00 2.3e-03 1.1e-03 2.0e-03 4.4e-03 Road building

Ag-110m 9.8e-01 4.8e-01 8.6e-01 1.9e+00 3.6e-03 1.8e-03 3.2e-03 7.0e-03 Road building

Cd-109 1.7e-03 8.4e-04 1.5e-03 3.2e-03 6.3e-06 3.1e-06 5.5e-06 1.2e-05 Road building

Sn-113 7.4e-02 3.5e-02 6.5e-02 1.5e-01 2.8e-04 1.3e-04 2.4e-04 5.4e-04 Road building

Sb-124 5.2e-01 3.0e-01 5.1e-01 7.8e-01 1.9e-03 1.1e-03 1.9e-03 2.9e-03 Processing concrete

Sb-125 1.5e-01 7.4e-02 1.3e-01 2.9e-01 5.6e-04 2.8e-04 4.9e-04 1.1e-03 Road building

Te-123m 3.2e-02 1.5e-02 2.8e-02 6.3e-02 1.2e-04 5.6e-05 1.0e-04 2.3e-04 Road building

Te-127m 1.7e-03 8.1e-04 1.5e-03 3.4e-03 6.4e-06 3.0e-06 5.6e-06 1.2e-05 Road building

I-125 8.8e-04 3.7e-04 7.6e-04 1.8e-03 3.3e-06 1.4e-06 2.8e-06 6.7e-06 Road building

I-129 1.0e+00 0.0e+00 0.0e+00 4.6e+00 3.9e-03 0.0e+00 0.0e+00 1.7e-02 Leachate-industrial

I-131 3.6e-02 8.3e-03 2.8e-02 9.1e-02 1.3e-04 3.1e-05 1.0e-04 3.4e-04 Processing concrete

Cs-134 5.8e-01 2.8e-01 5.1e-01 1.1e+00 2.2e-03 1.1e-03 1.9e-03 4.2e-03 Road building

Cs-135 9.3e-05 0.0e+00 0.0e+00 0.0e+00 3.5e-07 0.0e+00 0.0e+00 0.0e+00 Leachate-MSW

Cs-137 2.2e-01 1.1e-01 1.9e-01 4.2e-01 8.0e-04 3.9e-04 7.0e-04 1.5e-03 Road building

Ba-133 1.3e-01 6.1e-02 1.1e-01 2.4e-01 4.6e-04 2.3e-04 4.1e-04 9.0e-04 Road building

Ce-139 3.4e-02 1.6e-02 2.9e-02 6.5e-02 1.2e-04 5.9e-05 1.1e-04 2.4e-04 Road building

Ce-141 1.1e-02 6.2e-03 1.1e-02 1.8e-02 4.2e-05 2.3e-05 4.1e-05 6.7e-05 Processing concrete

Ce-144 1.9e-02 9.1e-03 1.6e-02 3.6e-02 7.0e-05 3.4e-05 6.1e-05 1.3e-04 Road building

Pm-147 2.1e-05 9.1e-06 2.1e-05 3.4e-05 7.8e-08 3.4e-08 7.7e-08 1.3e-07 Processing concrete

Sm-151 9.5e-06 4.5e-06 9.5e-06 1.5e-05 3.5e-08 1.7e-08 3.5e-08 5.5e-08 Processing concrete

Eu-152 4.4e-01 2.2e-01 3.9e-01 8.6e-01 1.6e-03 8.0e-04 1.4e-03 3.2e-03 Road building

Eu-154 4.9e-01 2.4e-01 4.3e-01 9.4e-01 1.8e-03 8.8e-04 1.6e-03 3.5e-03 Road building

Eu-155 1.1e-02 5.6e-03 1.0e-02 2.2e-02 4.2e-05 2.1e-05 3.7e-05 8.2e-05 Road building

Gd-153 1.4e-02 6.8e-03 1.2e-02 2.7e-02 5.2e-05 2.5e-05 4.5e-05 1.0e-04 Road building

Tb-160 3.1e-01 1.8e-01 3.1e-01 4.7e-01 1.2e-03 6.8e-04 1.1e-03 1.7e-03 Processing concrete

Tm-170 8.1e-04 3.9e-04 7.1e-04 1.6e-03 3.0e-06 1.4e-06 2.6e-06 5.8e-06 Road building

Tm-171 7.2e-05 3.6e-05 6.3e-05 1.4e-04 2.7e-07 1.3e-07 2.3e-07 5.1e-07 Road building

Ta-182 4.0e-01 1.9e-01 3.5e-01 7.9e-01 1.5e-03 7.0e-04 1.3e-03 2.9e-03 Road building

W-181 3.9e-03 1.9e-03 3.4e-03 7.7e-03 1.5e-05 6.9e-06 1.3e-05 2.8e-05 Road building

W-185 3.4e-05 1.7e-05 3.4e-05 5.5e-05 1.3e-07 6.2e-08 1.2e-07 2.0e-07 Processing concrete

Os-185 2.0e-01 9.2e-02 1.8e-01 4.0e-01 7.4e-04 3.4e-04 6.5e-04 1.5e-03 Road building

Ir-192 2.1e-01 9.2e-02 1.8e-01 4.1e-01 7.7e-04 3.4e-04 6.7e-04 1.5e-03 Road building

Tl-204 2.8e-04 1.4e-04 2.4e-04 5.3e-04 1.0e-06 5.1e-07 9.0e-07 2.0e-06 Road building

Pb-210 9.1e-02 1.2e-02 8.9e-02 1.8e-01 3.4e-04 4.4e-05 3.3e-04 6.6e-04 Processing concrete

Bi-207 6.0e-01 2.9e-01 5.2e-01 1.2e+00 2.2e-03 1.1e-03 1.9e-03 4.3e-03 Road building

Po-210 2.2e-02 3.2e-03 2.2e-02 4.3e-02 8.3e-05 1.2e-05 8.1e-05 1.6e-04 Processing concrete

Ra-226 7.2e-01 3.5e-01 6.3e-01 1.4e+00 2.7e-03 1.3e-03 2.3e-03 5.1e-03 Road building

Ra-228 4.1e-01 2.0e-01 3.6e-01 7.9e-01 1.5e-03 7.5e-04 1.3e-03 2.9e-03 Road building

a 5th percentile to 95th percentile = 90% confidence interval
Chapter 6 Recycling and Disposal of Concrete Rubble

Table 6.6 Normalized surficial effective dose equivalents to critical groups for concrete

Radionuclide

:Sv/y per Bq/cm2 mrem/y per pCi/cm2

Mean

Percentilea

Mean

Percentilea

Scenario

5th 50th 95th 5th 50th 95th

6-19 NUREG-1640

Ac-227 5.0e-01 2.9e-01 4.9e-01 7.3e-01 1.8e-03 1.1e-03 1.8e-03 2.7e-03 Processing concrete

Th-228 6.5e-01 3.2e-01 5.7e-01 1.2e+00 2.4e-03 1.2e-03 2.1e-03 4.6e-03 Road building

Th-229 4.8e-01 3.0e-01 4.6e-01 7.0e-01 1.8e-03 1.1e-03 1.7e-03 2.6e-03 Processing concrete

Th-230 6.3e-02 3.4e-02 6.0e-02 1.0e-01 2.3e-04 1.3e-04 2.2e-04 3.8e-04 Truck driver

Th-232 3.2e-01 1.7e-01 3.0e-01 5.2e-01 1.2e-03 6.4e-04 1.1e-03 1.9e-03 Truck driver

Pa-231 3.4e-01 1.8e-01 3.4e-01 5.2e-01 1.3e-03 6.8e-04 1.3e-03 1.9e-03 Processing concrete

U-232 1.3e-01 7.3e-02 1.3e-01 2.1e-01 4.9e-04 2.7e-04 4.6e-04 7.9e-04 Truck driver

U-233 1.1e-01 0.0e+00 0.0e+00 0.0e+00 4.1e-04 0.0e+00 0.0e+00 0.0e+00 Leachate-MSW

U-234 8.1e-02 0.0e+00 0.0e+00 0.0e+00 3.0e-04 0.0e+00 0.0e+00 0.0e+00 Leachate-MSW

U-235 1.2e-01 0.0e+00 0.0e+00 0.0e+00 4.3e-04 0.0e+00 0.0e+00 0.0e+00 Leachate-MSW

U-236 7.5e-02 0.0e+00 0.0e+00 0.0e+00 2.8e-04 0.0e+00 0.0e+00 0.0e+00 Leachate-MSW

U-238 7.5e-02 0.0e+00 0.0e+00 0.0e+00 2.8e-04 0.0e+00 0.0e+00 0.0e+00 Leachate-MSW

Np-237 3.8e+00 0.0e+00 0.0e+00 8.5e+00 1.4e-02 0.0e+00 0.0e+00 3.2e-02 Leachate-industrial

Pu-236 3.7e-02 1.9e-02 3.7e-02 5.6e-02 1.4e-04 7.2e-05 1.4e-04 2.1e-04 Processing concrete

Pu-238 1.0e-01 5.3e-02 1.0e-01 1.6e-01 3.8e-04 2.0e-04 3.7e-04 5.7e-04 Processing concrete

Pu-239 1.1e-01 5.8e-02 1.1e-01 1.7e-01 4.1e-04 2.2e-04 4.1e-04 6.3e-04 Processing concrete

Pu-240 1.1e-01 5.8e-02 1.1e-01 1.7e-01 4.1e-04 2.2e-04 4.1e-04 6.3e-04 Processing concrete

Pu-241 2.2e-03 1.1e-03 2.1e-03 3.3e-03 8.0e-06 4.2e-06 7.9e-06 1.2e-05 Processing concrete

Pu-242 1.1e-01 5.6e-02 1.1e-01 1.6e-01 3.9e-04 2.1e-04 3.9e-04 6.0e-04 Processing concrete

Pu-244 2.1e-01 1.4e-01 2.1e-01 2.8e-01 7.7e-04 5.2e-04 7.6e-04 1.0e-03 Processing concrete

Am-241 1.2e-01 6.2e-02 1.2e-01 1.8e-01 4.3e-04 2.3e-04 4.3e-04 6.6e-04 Processing concrete

Am-242m 1.2e-01 6.3e-02 1.2e-01 1.8e-01 4.4e-04 2.3e-04 4.3e-04 6.6e-04 Processing concrete

Am-243 1.6e-01 1.0e-01 1.6e-01 2.3e-01 5.9e-04 3.8e-04 5.9e-04 8.4e-04 Processing concrete

Cm-242 3.9e-03 2.1e-03 3.9e-03 6.0e-03 1.5e-05 7.9e-06 1.4e-05 2.2e-05 Processing concrete

Cm-243 1.1e-01 6.8e-02 1.1e-01 1.5e-01 4.0e-04 2.5e-04 4.0e-04 5.7e-04 Processing concrete

Cm-244 6.4e-02 3.4e-02 6.3e-02 9.8e-02 2.4e-04 1.2e-04 2.3e-04 3.6e-04 Processing concrete

Cm-245 1.4e-01 7.9e-02 1.4e-01 2.0e-01 5.1e-04 2.9e-04 5.0e-04 7.4e-04 Processing concrete

Cm-246 1.2e-01 6.1e-02 1.2e-01 1.8e-01 4.3e-04 2.3e-04 4.3e-04 6.6e-04 Processing concrete

Cm-247 2.0e-01 1.4e-01 2.0e-01 2.8e-01 7.6e-04 5.1e-04 7.5e-04 1.0e-03 Processing concrete

Cm-248 4.3e-01 2.3e-01 4.3e-01 6.6e-01 1.6e-03 8.3e-04 1.6e-03 2.4e-03 Processing concrete

Bk-249 3.7e-04 2.0e-04 3.7e-04 5.7e-04 1.4e-06 7.3e-07 1.4e-06 2.1e-06 Processing concrete

Cf-248 1.2e-02 6.5e-03 1.2e-02 1.8e-02 4.4e-05 2.4e-05 4.3e-05 6.7e-05 Processing concrete

Cf-249 2.1e-01 1.4e-01 2.1e-01 3.0e-01 7.9e-04 5.1e-04 7.8e-04 1.1e-03 Processing concrete

Cf-250 5.9e-02 2.9e-02 5.8e-02 9.1e-02 2.2e-04 1.1e-04 2.2e-04 3.3e-04 Processing concrete

Cf-251 1.5e-01 8.1e-02 1.4e-01 2.2e-01 5.4e-04 3.0e-04 5.3e-04 8.0e-04 Processing concrete

Cf-252 3.8e-02 2.0e-02 3.7e-02 5.7e-02 1.4e-04 7.6e-05 1.4e-04 2.1e-04 Processing concrete

Cf-254 4.9e+00 2.9e+00 4.8e+00 7.3e+00 1.8e-02 1.1e-02 1.8e-02 2.7e-02 Processing concrete

Es-254 3.3e-01 1.6e-01 2.9e-01 6.3e-01 1.2e-03 5.9e-04 1.1e-03 2.3e-03 Road building

a 5th percentile to 95th percentile = 90% confidence interval
Recycling and Disposal of Concrete Rubble Chapter 6

NUREG-1640 6-20

Table 6.7 Normalized mass-based effective doses to critical groups for concrete

Radionuclide

:Sv/y per Bq/g mrem/y per pCi/g

Mean

Percentilea

Mean

Percentilea

Scenario

5th 50th 95th 5th 50th 95th

H-3 6.9e-02 0.0e+00 4.6e-05 3.0e-01 2.5e-04 0.0e+00 1.7e-07 1.1e-03 Leachate-industrial

C-14 1.2e-01 0.0e+00 0.0e+00 2.9e-01 4.4e-04 0.0e+00 0.0e+00 1.1e-03 Leachate-industrial

Na-22 2.2e+02 1.1e+02 2.0e+02 4.3e+02 8.3e-01 4.1e-01 7.3e-01 1.6e+00 Road building

P-32 1.1e-01 4.4e-02 9.6e-02 2.0e-01 4.0e-04 1.6e-04 3.5e-04 7.5e-04 Processing concrete

S-35 1.9e-03 4.8e-04 1.8e-03 3.4e-03 6.9e-06 1.8e-06 6.8e-06 1.3e-05 Processing concrete

Cl-36 1.5e+00 0.0e+00 0.0e+00 7.0e+00 5.5e-03 0.0e+00 0.0e+00 2.6e-02 Leachate-industrial

K-40 1.8e+01 8.7e+00 1.6e+01 3.4e+01 6.6e-02 3.2e-02 5.8e-02 1.3e-01 Road building

Ca-41 6.1e-01 0.0e+00 0.0e+00 3.1e+00 2.2e-03 0.0e+00 0.0e+00 1.2e-02 Leachate-industrial

Ca-45 1.0e-02 2.0e-03 9.8e-03 1.9e-02 3.7e-05 7.4e-06 3.6e-05 7.0e-05 Processing concrete

Sc-46 1.7e+02 9.9e+01 1.6e+02 2.4e+02 6.1e-01 3.7e-01 6.0e-01 9.0e-01 Processing concrete

Cr-51 1.8e+00 9.4e-01 1.7e+00 2.9e+00 6.5e-03 3.5e-03 6.2e-03 1.1e-02 Processing concrete

Mn-53 1.6e-03 0.0e+00 0.0e+00 0.0e+00 5.8e-06 0.0e+00 0.0e+00 0.0e+00 Leachate-industrial

Mn-54 8.0e+01 3.9e+01 7.0e+01 1.5e+02 3.0e-01 1.4e-01 2.6e-01 5.7e-01 Road building

Fe-55 4.2e-03 5.2e-04 4.1e-03 8.2e-03 1.6e-05 1.9e-06 1.5e-05 3.0e-05 Processing concrete

Fe-59 8.9e+01 5.1e+01 8.7e+01 1.4e+02 3.3e-01 1.9e-01 3.2e-01 5.0e-01 Processing concrete

Co-56 3.0e+02 1.8e+02 2.9e+02 4.4e+02 1.1e+00 6.6e-01 1.1e+00 1.6e+00 Processing concrete

Co-57 7.4e+00 3.6e+00 6.5e+00 1.4e+01 2.7e-02 1.3e-02 2.4e-02 5.3e-02 Road building

Co-58 7.6e+01 4.5e+01 7.5e+01 1.1e+02 2.8e-01 1.7e-01 2.8e-01 4.2e-01 Processing concrete

Co-60 2.7e+02 1.3e+02 2.4e+02 5.2e+02 1.0e+00 4.9e-01 8.8e-01 1.9e+00 Road building

Ni-59 2.2e-03 1.2e-03 2.2e-03 3.3e-03 8.2e-06 4.6e-06 8.1e-06 1.2e-05 Processing concrete

Ni-63 2.0e-03 2.6e-04 1.9e-03 3.8e-03 7.2e-06 9.6e-07 7.1e-06 1.4e-05 Processing concrete

Zn-65 5.6e+01 2.7e+01 4.9e+01 1.1e+02 2.1e-01 1.0e-01 1.8e-01 4.0e-01 Road building

As-73 1.0e-01 4.6e-02 9.0e-02 2.1e-01 3.8e-04 1.7e-04 3.3e-04 7.6e-04 Road building

Se-75 2.6e+01 1.2e+01 2.3e+01 5.1e+01 9.7e-02 4.6e-02 8.5e-02 1.9e-01 Road building

Sr-85 3.6e+01 2.1e+01 3.6e+01 5.4e+01 1.3e-01 7.9e-02 1.3e-01 2.0e-01 Processing concrete

Sr-89 1.8e-01 7.0e-02 1.5e-01 3.7e-01 6.5e-04 2.6e-04 5.6e-04 1.4e-03 Road building

Sr-90 1.1e+00 0.0e+00 0.0e+00 2.0e-06 4.0e-03 0.0e+00 0.0e+00 7.3e-09 Leachate-industrial

Y-91 4.5e-01 1.9e-01 3.9e-01 9.3e-01 1.7e-03 7.0e-04 1.4e-03 3.4e-03 Road building

Zr-93 4.6e-03 1.4e-03 4.6e-03 8.1e-03 1.7e-05 5.2e-06 1.7e-05 3.0e-05 Processing concrete

Zr-95 8.1e+01 3.9e+01 7.1e+01 1.5e+02 3.0e-01 1.5e-01 2.6e-01 5.7e-01 Road building

Nb-93m 2.8e-03 1.3e-03 2.7e-03 4.4e-03 1.0e-05 4.8e-06 1.0e-05 1.6e-05 Processing concrete

Nb-94 1.6e+02 8.0e+01 1.4e+02 3.1e+02 6.0e-01 3.0e-01 5.3e-01 1.2e+00 Road building

Nb-95 5.1e+01 2.9e+01 5.0e+01 8.0e+01 1.9e-01 1.1e-01 1.8e-01 3.0e-01 Processing concrete

Mo-93 9.0e-01 0.0e+00 0.0e+00 1.2e+00 3.3e-03 0.0e+00 0.0e+00 4.6e-03 Leachate-industrial

Tc-97 1.3e+00 0.0e+00 0.0e+00 6.0e+00 4.7e-03 0.0e+00 0.0e+00 2.2e-02 Leachate-industrial

Tc-97m 2.8e-02 1.6e-02 2.7e-02 4.0e-02 1.0e-04 6.1e-05 1.0e-04 1.5e-04 Processing concrete

Tc-99 1.2e+01 0.0e+00 0.0e+00 5.6e+01 4.4e-02 0.0e+00 0.0e+00 2.1e-01 Leachate-industrial

Ru-103 3.3e+01 1.8e+01 3.2e+01 5.0e+01 1.2e-01 6.8e-02 1.2e-01 1.9e-01 Processing concrete

Ru-106 2.1e+01 1.0e+01 1.8e+01 4.0e+01 7.7e-02 3.8e-02 6.7e-02 1.5e-01 Road building

a 5th percentile to 95th percentile = 90% confidence interval
Chapter 6 Recycling and Disposal of Concrete Rubble

Table 6.7 Normalized mass-based effective doses to critical groups for concrete

Radionuclide

:Sv/y per Bq/g mrem/y per pCi/g

Mean

Percentilea

Mean

Percentilea

Scenario

5th 50th 95th 5th 50th 95th

6-21 NUREG-1640

Ag-108m 1.6e+02 7.9e+01 1.4e+02 3.1e+02 6.0e-01 2.9e-01 5.2e-01 1.1e+00 Road building

Ag-110m 2.6e+02 1.3e+02 2.3e+02 5.0e+02 9.6e-01 4.7e-01 8.4e-01 1.9e+00 Road building

Cd-109 3.9e-01 1.9e-01 3.5e-01 7.5e-01 1.5e-03 7.2e-04 1.3e-03 2.8e-03 Road building

Sn-113 2.0e+01 1.2e+01 1.9e+01 2.9e+01 7.2e-02 4.4e-02 7.1e-02 1.1e-01 Processing concrete

Sb-124 1.5e+02 8.6e+01 1.4e+02 2.2e+02 5.4e-01 3.2e-01 5.3e-01 8.1e-01 Processing concrete

Sb-125 4.0e+01 1.9e+01 3.5e+01 7.6e+01 1.5e-01 7.2e-02 1.3e-01 2.8e-01 Road building

Te-123m 8.2e+00 3.9e+00 7.2e+00 1.6e+01 3.0e-02 1.4e-02 2.7e-02 5.9e-02 Road building

Te-127m 4.6e-01 2.8e-01 4.5e-01 6.6e-01 1.7e-03 1.0e-03 1.7e-03 2.5e-03 Processing concrete

I-125 3.1e-01 1.4e-01 3.0e-01 4.9e-01 1.1e-03 5.3e-04 1.1e-03 1.8e-03 Processing concrete

I-129 4.3e+02 0.0e+00 0.0e+00 1.9e+03 1.6e+00 0.0e+00 0.0e+00 7.1e+00 Leachate-industrial

I-131 1.0e+01 2.4e+00 7.8e+00 2.6e+01 3.8e-02 8.7e-03 2.9e-02 9.5e-02 Processing concrete

Cs-134 1.5e+02 7.5e+01 1.3e+02 2.9e+02 5.7e-01 2.8e-01 5.0e-01 1.1e+00 Road building

Cs-135 2.7e-02 0.0e+00 0.0e+00 0.0e+00 1.0e-04 0.0e+00 0.0e+00 0.0e+00 Leachate-MSW

Cs-137 5.7e+01 2.8e+01 5.0e+01 1.1e+02 2.1e-01 1.0e-01 1.9e-01 4.0e-01 Road building

Ba-133 3.2e+01 1.6e+01 2.8e+01 6.2e+01 1.2e-01 5.8e-02 1.0e-01 2.3e-01 Road building

Ce-139 8.6e+00 4.1e+00 7.5e+00 1.7e+01 3.2e-02 1.5e-02 2.8e-02 6.2e-02 Road building

Ce-141 3.2e+00 1.8e+00 3.1e+00 5.1e+00 1.2e-02 6.5e-03 1.1e-02 1.9e-02 Processing concrete

Ce-144 5.4e+00 2.6e+00 4.7e+00 1.0e+01 2.0e-02 9.7e-03 1.7e-02 3.8e-02 Road building

Pm-147 4.4e-03 1.5e-03 4.3e-03 7.6e-03 1.6e-05 5.5e-06 1.6e-05 2.8e-05 Processing concrete

Sm-151 1.7e-03 5.4e-04 1.7e-03 2.9e-03 6.2e-06 2.0e-06 6.1e-06 1.1e-05 Processing concrete

Eu-152 1.2e+02 5.8e+01 1.0e+02 2.3e+02 4.4e-01 2.1e-01 3.8e-01 8.3e-01 Road building

Eu-154 1.3e+02 6.3e+01 1.1e+02 2.5e+02 4.8e-01 2.3e-01 4.2e-01 9.1e-01 Road building

Eu-155 2.9e+00 1.4e+00 2.5e+00 5.5e+00 1.1e-02 5.2e-03 9.3e-03 2.0e-02 Road building

Gd-153 3.4e+00 1.7e+00 3.0e+00 6.6e+00 1.3e-02 6.1e-03 1.1e-02 2.4e-02 Road building

Tb-160 8.8e+01 5.2e+01 8.7e+01 1.3e+02 3.3e-01 1.9e-01 3.2e-01 4.8e-01 Processing concrete

Tm-170 2.1e-01 1.0e-01 1.9e-01 4.1e-01 7.9e-04 3.8e-04 6.9e-04 1.5e-03 Road building

Tm-171 1.7e-02 8.5e-03 1.5e-02 3.2e-02 6.3e-05 3.1e-05 5.5e-05 1.2e-04 Road building

Ta-182 1.1e+02 5.0e+01 9.3e+01 2.1e+02 4.0e-01 1.9e-01 3.4e-01 7.7e-01 Road building

W-181 9.4e-01 4.4e-01 8.2e-01 1.8e+00 3.5e-03 1.6e-03 3.0e-03 6.8e-03 Road building

W-185 9.8e-03 4.8e-03 9.6e-03 1.6e-02 3.6e-05 1.8e-05 3.6e-05 5.8e-05 Processing concrete

Os-185 5.3e+01 2.4e+01 4.6e+01 1.0e+02 2.0e-01 9.0e-02 1.7e-01 3.9e-01 Road building

Ir-192 5.8e+01 3.5e+01 5.7e+01 8.6e+01 2.2e-01 1.3e-01 2.1e-01 3.2e-01 Processing concrete

Tl-204 7.8e-02 3.9e-02 6.8e-02 1.5e-01 2.9e-04 1.4e-04 2.5e-04 5.5e-04 Road building

Pb-210 1.2e+01 1.7e+00 1.2e+01 2.3e+01 4.5e-02 6.2e-03 4.4e-02 8.7e-02 Processing concrete

Bi-207 1.6e+02 7.7e+01 1.4e+02 3.0e+02 5.8e-01 2.9e-01 5.1e-01 1.1e+00 Road building

Po-210 3.1e+00 5.9e-01 3.0e+00 5.8e+00 1.1e-02 2.2e-03 1.1e-02 2.2e-02 Processing concrete

Ra-226 1.9e+02 9.4e+01 1.7e+02 3.7e+02 7.1e-01 3.5e-01 6.2e-01 1.4e+00 Road building

Ra-228 1.1e+02 5.5e+01 9.8e+01 2.1e+02 4.1e-01 2.0e-01 3.6e-01 7.9e-01 Road building

a 5th percentile to 95th percentile = 90% confidence interval
Recycling and Disposal of Concrete Rubble Chapter 6

Table 6.7 Normalized mass-based effective doses to critical groups for concrete

Radionuclide

:Sv/y per Bq/g mrem/y per pCi/g

Mean

Percentilea

Mean

Percentilea

Scenario

5th 50th 95th 5th 50th 95th

NUREG-1640 6-22

Ac-227 5.6e+01 3.6e+01 5.6e+01 7.8e+01 2.1e-01 1.3e-01 2.1e-01 2.9e-01 Processing concrete

Th-228 1.7e+02 8.4e+01 1.5e+02 3.2e+02 6.3e-01 3.1e-01 5.5e-01 1.2e+00 Road building

Th-229 4.3e+01 2.9e+01 4.3e+01 5.8e+01 1.6e-01 1.1e-01 1.6e-01 2.1e-01 Processing concrete

Th-230 7.3e+00 3.9e+00 7.2e+00 1.1e+01 2.7e-02 1.5e-02 2.7e-02 4.1e-02 Processing concrete

Th-232 3.3e+01 5.5e+00 3.0e+01 7.5e+01 1.2e-01 2.0e-02 1.1e-01 2.8e-01 Driving on road

Pa-231 2.6e+01 1.5e+01 2.6e+01 3.9e+01 9.8e-02 5.6e-02 9.6e-02 1.4e-01 Processing concrete

U-232 2.9e+01 0.0e+00 0.0e+00 0.0e+00 1.1e-01 0.0e+00 0.0e+00 0.0e+00 Leachate-MSW

U-233 2.0e+01 0.0e+00 0.0e+00 0.0e+00 7.3e-02 0.0e+00 0.0e+00 0.0e+00 Leachate-MSW

U-234 1.5e+01 0.0e+00 0.0e+00 0.0e+00 5.5e-02 0.0e+00 0.0e+00 0.0e+00 Leachate-MSW

U-235 1.7e+01 0.0e+00 0.0e+00 0.0e+00 6.3e-02 0.0e+00 0.0e+00 0.0e+00 Leachate-MSW

U-236 1.4e+01 0.0e+00 0.0e+00 0.0e+00 5.0e-02 0.0e+00 0.0e+00 0.0e+00 Leachate-MSW

U-238 1.4e+01 0.0e+00 0.0e+00 0.0e+00 5.2e-02 0.0e+00 0.0e+00 0.0e+00 Leachate-MSW

Np-237 9.9e+01 0.0e+00 0.0e+00 2.2e+02 3.7e-01 0.0e+00 0.0e+00 8.1e-01 Leachate-industrial

Pu-236 3.2e+00 1.8e+00 3.2e+00 4.9e+00 1.2e-02 6.5e-03 1.2e-02 1.8e-02 Processing concrete

Pu-238 7.9e+00 4.2e+00 7.8e+00 1.2e+01 2.9e-02 1.6e-02 2.9e-02 4.4e-02 Processing concrete

Pu-239 8.5e+00 4.5e+00 8.4e+00 1.3e+01 3.1e-02 1.7e-02 3.1e-02 4.8e-02 Processing concrete

Pu-240 8.5e+00 4.5e+00 8.4e+00 1.3e+01 3.1e-02 1.7e-02 3.1e-02 4.7e-02 Processing concrete

Pu-241 1.6e-01 8.2e-02 1.5e-01 2.4e-01 5.8e-04 3.0e-04 5.7e-04 8.7e-04 Processing concrete

Pu-242 8.2e+00 4.4e+00 8.1e+00 1.2e+01 3.0e-02 1.6e-02 3.0e-02 4.6e-02 Processing concrete

Pu-244 3.9e+01 1.9e+01 3.4e+01 7.3e+01 1.4e-01 7.2e-02 1.2e-01 2.7e-01 Road building

Am-241 7.5e+00 4.3e+00 7.5e+00 1.1e+01 2.8e-02 1.6e-02 2.8e-02 4.1e-02 Processing concrete

Am-242m 8.0e+00 4.7e+00 7.9e+00 1.2e+01 3.0e-02 1.7e-02 2.9e-02 4.3e-02 Processing concrete

Am-243 2.0e+01 1.4e+01 2.0e+01 2.7e+01 7.4e-02 5.0e-02 7.3e-02 9.9e-02 Processing concrete

Cm-242 7.2e-01 4.2e-01 7.0e-01 1.1e+00 2.7e-03 1.6e-03 2.6e-03 4.1e-03 Processing concrete

Cm-243 1.3e+01 9.2e+00 1.3e+01 1.8e+01 4.9e-02 3.4e-02 4.9e-02 6.7e-02 Processing concrete

Cm-244 4.3e+00 2.3e+00 4.3e+00 6.5e+00 1.6e-02 8.7e-03 1.6e-02 2.4e-02 Processing concrete

Cm-245 1.2e+01 8.3e+00 1.2e+01 1.7e+01 4.6e-02 3.1e-02 4.5e-02 6.2e-02 Processing concrete

Cm-246 7.1e+00 3.8e+00 7.0e+00 1.1e+01 2.6e-02 1.4e-02 2.6e-02 4.0e-02 Processing concrete

Cm-247 3.4e+01 1.7e+01 3.0e+01 6.5e+01 1.3e-01 6.4e-02 1.1e-01 2.4e-01 Road building

Cm-248 2.6e+01 1.3e+01 2.5e+01 3.9e+01 9.4e-02 5.0e-02 9.3e-02 1.4e-01 Processing concrete

Bk-249 3.1e-02 1.7e-02 3.1e-02 4.7e-02 1.2e-04 6.2e-05 1.1e-04 1.7e-04 Processing concrete

Cf-248 1.3e+00 7.6e-01 1.3e+00 2.0e+00 4.9e-03 2.8e-03 4.8e-03 7.4e-03 Processing concrete

Cf-249 3.9e+01 2.6e+01 3.8e+01 5.2e+01 1.4e-01 9.7e-02 1.4e-01 1.9e-01 Processing concrete

Cf-250 5.7e+00 3.0e+00 5.6e+00 8.6e+00 2.1e-02 1.1e-02 2.1e-02 3.2e-02 Processing concrete

Cf-251 1.9e+01 1.3e+01 1.9e+01 2.6e+01 7.1e-02 4.7e-02 7.0e-02 9.7e-02 Processing concrete

Cf-252 3.3e+00 1.8e+00 3.2e+00 4.9e+00 1.2e-02 6.6e-03 1.2e-02 1.8e-02 Processing concrete

Cf-254 1.4e+03 8.1e+02 1.3e+03 2.0e+03 5.1e+00 3.0e+00 5.0e+00 7.5e+00 Processing concrete

Es-254 8.6e+01 4.2e+01 7.5e+01 1.7e+02 3.2e-01 1.6e-01 2.8e-01 6.1e-01 Road building

a 5th percentile to 95th percentile = 90% confidence interval
Chapter 6 Recycling and Disposal of Concrete Rubble

6-23 NUREG-1640

Table 6.8 Normalized surficial effective doses to critical groups for concrete

Radionuclide

:Sv/y per Bq/cm2 mrem/y per pCi/cm2

Scenario

Mean

Percentilea

Mean

Percentilea

5th 50th 95th 5th 50th 95th

H-3 2.5e-04 0.0e+00 1.6e-07 1.1e-03 9.1e-07 0.0e+00 6.0e-10 4.0e-06 Leachate-industrial

C-14 4.2e-04 0.0e+00 0.0e+00 1.0e-03 1.6e-06 0.0e+00 0.0e+00 3.7e-06 Leachate-industrial

Na-22 8.0e-01 3.9e-01 7.0e-01 1.5e+00 3.0e-03 1.4e-03 2.6e-03 5.7e-03 Road building

P-32 3.8e-04 1.6e-04 3.4e-04 7.3e-04 1.4e-06 5.8e-07 1.3e-06 2.7e-06 Processing concrete

S-35 6.7e-06 1.7e-06 6.6e-06 1.2e-05 2.5e-08 6.3e-09 2.4e-08 4.5e-08 Processing concrete

Cl-36 5.3e-03 0.0e+00 0.0e+00 2.5e-02 2.0e-05 0.0e+00 0.0e+00 9.3e-05 Leachate-industrial

K-40 6.4e-02 3.1e-02 5.6e-02 1.2e-01 2.4e-04 1.2e-04 2.1e-04 4.5e-04 Road building

Ca-41 2.2e-03 0.0e+00 0.0e+00 1.1e-02 8.0e-06 0.0e+00 0.0e+00 4.1e-05 Leachate-industrial

Ca-45 3.6e-05 7.0e-06 3.5e-05 6.7e-05 1.3e-07 2.6e-08 1.3e-07 2.5e-07 Processing concrete

Sc-46 5.9e-01 3.5e-01 5.8e-01 8.8e-01 2.2e-03 1.3e-03 2.2e-03 3.3e-03 Processing concrete

Cr-51 6.3e-03 3.3e-03 6.0e-03 1.0e-02 2.3e-05 1.2e-05 2.2e-05 3.8e-05 Processing concrete

Mn-53 5.6e-06 0.0e+00 0.0e+00 0.0e+00 2.1e-08 0.0e+00 0.0e+00 0.0e+00 Leachate-industrial

Mn-54 2.8e-01 1.4e-01 2.5e-01 5.5e-01 1.1e-03 5.1e-04 9.2e-04 2.0e-03 Road building

Fe-55 1.5e-05 1.8e-06 1.5e-05 2.9e-05 5.6e-08 6.8e-09 5.5e-08 1.1e-07 Processing concrete

Fe-59 3.2e-01 1.8e-01 3.1e-01 4.9e-01 1.2e-03 6.7e-04 1.1e-03 1.8e-03 Processing concrete

Co-56 1.1e+00 6.3e-01 1.0e+00 1.6e+00 4.0e-03 2.3e-03 3.9e-03 5.9e-03 Processing concrete

Co-57 2.6e-02 1.3e-02 2.3e-02 5.1e-02 9.7e-05 4.7e-05 8.5e-05 1.9e-04 Road building

Co-58 2.7e-01 1.6e-01 2.7e-01 4.0e-01 1.0e-03 5.9e-04 9.8e-04 1.5e-03 Processing concrete

Co-60 9.7e-01 4.7e-01 8.5e-01 1.9e+00 3.6e-03 1.8e-03 3.1e-03 6.9e-03 Road building

Ni-59 7.9e-06 4.4e-06 7.8e-06 1.2e-05 2.9e-08 1.6e-08 2.9e-08 4.4e-08 Processing concrete

Ni-63 7.0e-06 9.2e-07 6.8e-06 1.4e-05 2.6e-08 3.4e-09 2.5e-08 5.0e-08 Processing concrete

Zn-65 2.0e-01 9.7e-02 1.8e-01 3.9e-01 7.4e-04 3.6e-04 6.5e-04 1.4e-03 Road building

As-73 3.7e-04 1.7e-04 3.2e-04 7.3e-04 1.4e-06 6.1e-07 1.2e-06 2.7e-06 Road building

Se-75 9.4e-02 4.4e-02 8.2e-02 1.8e-01 3.5e-04 1.6e-04 3.0e-04 6.8e-04 Road building

Sr-85 1.3e-01 7.6e-02 1.3e-01 1.9e-01 4.8e-04 2.8e-04 4.7e-04 7.2e-04 Processing concrete

Sr-89 6.3e-04 2.5e-04 5.4e-04 1.3e-03 2.3e-06 9.3e-07 2.0e-06 4.9e-06 Road building

Sr-90 3.8e-03 0.0e+00 0.0e+00 7.0e-09 1.4e-05 0.0e+00 0.0e+00 2.6e-11 Leachate-industrial

Y-91 1.6e-03 6.7e-04 1.4e-03 3.3e-03 6.0e-06 2.5e-06 5.1e-06 1.2e-05 Road building

Zr-93 1.6e-05 5.0e-06 1.6e-05 2.9e-05 6.1e-08 1.8e-08 6.0e-08 1.1e-07 Processing concrete

Zr-95 2.9e-01 1.4e-01 2.5e-01 5.6e-01 1.1e-03 5.2e-04 9.3e-04 2.1e-03 Road building

Nb-93m 9.9e-06 4.6e-06 9.8e-06 1.6e-05 3.7e-08 1.7e-08 3.6e-08 5.8e-08 Processing concrete

Nb-94 5.8e-01 2.8e-01 5.1e-01 1.1e+00 2.2e-03 1.1e-03 1.9e-03 4.1e-03 Road building

Nb-95 1.8e-01 1.0e-01 1.8e-01 2.9e-01 6.8e-04 3.8e-04 6.6e-04 1.1e-03 Processing concrete

Mo-93 3.2e-03 0.0e+00 0.0e+00 4.4e-03 1.2e-05 0.0e+00 0.0e+00 1.6e-05 Leachate-industrial

Tc-97 4.6e-03 0.0e+00 0.0e+00 2.1e-02 1.7e-05 0.0e+00 0.0e+00 7.9e-05 Leachate-industrial

Tc-97m 9.9e-05 5.8e-05 9.7e-05 1.5e-04 3.7e-07 2.1e-07 3.6e-07 5.4e-07 Processing concrete

Tc-99 4.3e-02 0.0e+00 0.0e+00 2.0e-01 1.6e-04 0.0e+00 0.0e+00 7.4e-04 Leachate-industrial

Ru-103 1.2e-01 6.6e-02 1.1e-01 1.8e-01 4.3e-04 2.4e-04 4.2e-04 6.7e-04 Processing concrete

Ru-106 7.4e-02 3.6e-02 6.5e-02 1.4e-01 2.7e-04 1.3e-04 2.4e-04 5.3e-04 Road building

a 5th percentile to 95th percentile = 90% confidence interval
Recycling and Disposal of Concrete Rubble Chapter 6

Table 6.8 Normalized surficial effective doses to critical groups for concrete

Radionuclide

:Sv/y per Bq/cm2 mrem/y per pCi/cm2

Scenario

Mean

Percentilea

Mean

Percentilea

5th 50th 95th 5th 50th 95th

NUREG-1640 6-24

Ag-108m 5.8e-01 2.8e-01 5.0e-01 1.1e+00 2.1e-03 1.0e-03 1.9e-03 4.1e-03 Road building

Ag-110m 9.3e-01 4.5e-01 8.1e-01 1.8e+00 3.4e-03 1.7e-03 3.0e-03 6.6e-03 Road building

Cd-109 1.4e-03 6.9e-04 1.2e-03 2.7e-03 5.2e-06 2.6e-06 4.6e-06 1.0e-05 Road building

Sn-113 7.0e-02 4.2e-02 6.9e-02 1.0e-01 2.6e-04 1.5e-04 2.5e-04 3.8e-04 Processing concrete

Sb-124 5.2e-01 3.1e-01 5.1e-01 7.9e-01 1.9e-03 1.1e-03 1.9e-03 2.9e-03 Processing concrete

Sb-125 1.4e-01 6.9e-02 1.2e-01 2.7e-01 5.2e-04 2.6e-04 4.6e-04 1.0e-03 Road building

Te-123m 2.9e-02 1.4e-02 2.6e-02 5.7e-02 1.1e-04 5.1e-05 9.5e-05 2.1e-04 Road building

Te-127m 1.6e-03 1.0e-03 1.6e-03 2.4e-03 6.0e-06 3.7e-06 6.0e-06 8.8e-06 Processing concrete

I-125 1.1e-03 5.1e-04 1.1e-03 1.8e-03 4.0e-06 1.9e-06 3.9e-06 6.6e-06 Processing concrete

I-129 1.5e+00 0.0e+00 0.0e+00 6.8e+00 5.7e-03 0.0e+00 0.0e+00 2.5e-02 Leachate-industrial

I-131 3.6e-02 8.3e-03 2.8e-02 9.2e-02 1.3e-04 3.1e-05 1.0e-04 3.4e-04 Processing concrete

Cs-134 5.5e-01 2.7e-01 4.8e-01 1.1e+00 2.0e-03 9.9e-04 1.8e-03 3.9e-03 Road building

Cs-135 9.8e-05 0.0e+00 0.0e+00 0.0e+00 3.6e-07 0.0e+00 0.0e+00 0.0e+00 Leachate-MSW

Cs-137 2.0e-01 1.0e-01 1.8e-01 3.9e-01 7.5e-04 3.7e-04 6.6e-04 1.4e-03 Road building

Ba-133 1.2e-01 5.6e-02 1.0e-01 2.2e-01 4.3e-04 2.1e-04 3.7e-04 8.2e-04 Road building

Ce-139 3.1e-02 1.5e-02 2.7e-02 5.9e-02 1.1e-04 5.4e-05 9.9e-05 2.2e-04 Road building

Ce-141 1.1e-02 6.3e-03 1.1e-02 1.8e-02 4.2e-05 2.3e-05 4.1e-05 6.8e-05 Processing concrete

Ce-144 1.9e-02 9.3e-03 1.7e-02 3.7e-02 7.1e-05 3.4e-05 6.2e-05 1.4e-04 Road building

Pm-147 1.6e-05 5.3e-06 1.6e-05 2.7e-05 5.8e-08 2.0e-08 5.7e-08 1.0e-07 Processing concrete

Sm-151 6.0e-06 1.9e-06 5.9e-06 1.0e-05 2.2e-08 7.1e-09 2.2e-08 3.8e-08 Processing concrete

Eu-152 4.2e-01 2.1e-01 3.7e-01 8.1e-01 1.6e-03 7.6e-04 1.4e-03 3.0e-03 Road building

Eu-154 4.6e-01 2.2e-01 4.0e-01 8.9e-01 1.7e-03 8.3e-04 1.5e-03 3.3e-03 Road building

Eu-155 1.0e-02 5.0e-03 8.9e-03 2.0e-02 3.8e-05 1.8e-05 3.3e-05 7.3e-05 Road building

Gd-153 1.2e-02 5.9e-03 1.1e-02 2.4e-02 4.5e-05 2.2e-05 3.9e-05 8.7e-05 Road building

Tb-160 3.2e-01 1.9e-01 3.1e-01 4.7e-01 1.2e-03 6.9e-04 1.1e-03 1.7e-03 Processing concrete

Tm-170 7.6e-04 3.6e-04 6.7e-04 1.5e-03 2.8e-06 1.3e-06 2.5e-06 5.5e-06 Road building

Tm-171 6.1e-05 3.0e-05 5.3e-05 1.2e-04 2.3e-07 1.1e-07 2.0e-07 4.3e-07 Road building

Ta-182 3.8e-01 1.8e-01 3.3e-01 7.5e-01 1.4e-03 6.6e-04 1.2e-03 2.8e-03 Road building

W-181 3.3e-03 1.6e-03 2.9e-03 6.5e-03 1.2e-05 5.8e-06 1.1e-05 2.4e-05 Road building

W-185 3.5e-05 1.7e-05 3.4e-05 5.6e-05 1.3e-07 6.3e-08 1.3e-07 2.1e-07 Processing concrete

Os-185 1.9e-01 8.6e-02 1.6e-01 3.7e-01 7.0e-04 3.2e-04 6.1e-04 1.4e-03 Road building

Ir-192 2.1e-01 1.2e-01 2.0e-01 3.1e-01 7.7e-04 4.6e-04 7.5e-04 1.1e-03 Processing concrete

Tl-204 2.8e-04 1.4e-04 2.4e-04 5.3e-04 1.0e-06 5.1e-07 9.0e-07 2.0e-06 Road building

Pb-210 4.3e-02 6.0e-03 4.2e-02 8.4e-02 1.6e-04 2.2e-05 1.6e-04 3.1e-04 Processing concrete

Bi-207 5.6e-01 2.7e-01 4.9e-01 1.1e+00 2.1e-03 1.0e-03 1.8e-03 4.0e-03 Road building

Po-210 1.1e-02 2.1e-03 1.1e-02 2.1e-02 4.1e-05 7.8e-06 4.0e-05 7.7e-05 Processing concrete

Ra-226 6.8e-01 3.3e-01 6.0e-01 1.3e+00 2.5e-03 1.2e-03 2.2e-03 4.9e-03 Road building

Ra-228 4.0e-01 2.0e-01 3.5e-01 7.6e-01 1.5e-03 7.3e-04 1.3e-03 2.8e-03 Road building

a 5th percentile to 95th percentile = 90% confidence interval
Chapter 6 Recycling and Disposal of Concrete Rubble

Table 6.8 Normalized surficial effective doses to critical groups for concrete

Radionuclide

:Sv/y per Bq/cm2 mrem/y per pCi/cm2

Scenario

Mean

Percentilea

Mean

Percentilea

5th 50th 95th 5th 50th 95th

6-25 NUREG-1640

Ac-227 2.0e-01 1.3e-01 2.0e-01 2.8e-01 7.4e-04 4.6e-04 7.3e-04 1.0e-03 Processing concrete

Th-228 6.0e-01 3.0e-01 5.3e-01 1.2e+00 2.2e-03 1.1e-03 2.0e-03 4.3e-03 Road building

Th-229 1.5e-01 1.0e-01 1.5e-01 2.1e-01 5.7e-04 3.8e-04 5.6e-04 7.7e-04 Processing concrete

Th-230 2.6e-02 1.4e-02 2.6e-02 4.0e-02 9.7e-05 5.1e-05 9.5e-05 1.5e-04 Processing concrete

Th-232 1.2e-01 2.0e-02 1.1e-01 2.7e-01 4.4e-04 7.4e-05 3.9e-04 1.0e-03 Driving on road

Pa-231 9.4e-02 5.3e-02 9.3e-02 1.4e-01 3.5e-04 2.0e-04 3.4e-04 5.1e-04 Processing concrete

U-232 1.0e-01 0.0e+00 0.0e+00 0.0e+00 3.8e-04 0.0e+00 0.0e+00 0.0e+00 Leachate-MSW

U-233 6.9e-02 0.0e+00 0.0e+00 0.0e+00 2.6e-04 0.0e+00 0.0e+00 0.0e+00 Leachate-MSW

U-234 5.2e-02 0.0e+00 0.0e+00 0.0e+00 1.9e-04 0.0e+00 0.0e+00 0.0e+00 Leachate-MSW

U-235 6.0e-02 0.0e+00 0.0e+00 0.0e+00 2.2e-04 0.0e+00 0.0e+00 0.0e+00 Leachate-MSW

U-236 4.8e-02 0.0e+00 0.0e+00 0.0e+00 1.8e-04 0.0e+00 0.0e+00 0.0e+00 Leachate-MSW

U-238 4.9e-02 0.0e+00 0.0e+00 0.0e+00 1.8e-04 0.0e+00 0.0e+00 0.0e+00 Leachate-MSW

Np-237 3.5e-01 0.0e+00 0.0e+00 7.9e-01 1.3e-03 0.0e+00 0.0e+00 2.9e-03 Leachate-industrial

Pu-236 1.2e-02 6.2e-03 1.1e-02 1.7e-02 4.3e-05 2.3e-05 4.2e-05 6.4e-05 Processing concrete

Pu-238 2.8e-02 1.5e-02 2.8e-02 4.3e-02 1.0e-04 5.5e-05 1.0e-04 1.6e-04 Processing concrete

Pu-239 3.0e-02 1.6e-02 3.0e-02 4.6e-02 1.1e-04 5.9e-05 1.1e-04 1.7e-04 Processing concrete

Pu-240 3.0e-02 1.6e-02 3.0e-02 4.6e-02 1.1e-04 5.9e-05 1.1e-04 1.7e-04 Processing concrete

Pu-241 5.6e-04 2.9e-04 5.5e-04 8.5e-04 2.1e-06 1.1e-06 2.0e-06 3.1e-06 Processing concrete

Pu-242 2.9e-02 1.5e-02 2.9e-02 4.4e-02 1.1e-04 5.7e-05 1.1e-04 1.6e-04 Processing concrete

Pu-244 1.4e-01 6.9e-02 1.2e-01 2.6e-01 5.1e-04 2.6e-04 4.4e-04 9.6e-04 Road building

Am-241 2.7e-02 1.5e-02 2.7e-02 4.0e-02 1.0e-04 5.6e-05 9.8e-05 1.5e-04 Processing concrete

Am-242m 2.8e-02 1.7e-02 2.8e-02 4.2e-02 1.1e-04 6.2e-05 1.0e-04 1.5e-04 Processing concrete

Am-243 7.1e-02 4.8e-02 7.0e-02 9.7e-02 2.6e-04 1.8e-04 2.6e-04 3.6e-04 Processing concrete

Cm-242 2.6e-03 1.5e-03 2.5e-03 4.0e-03 9.6e-06 5.5e-06 9.3e-06 1.5e-05 Processing concrete

Cm-243 4.8e-02 3.2e-02 4.7e-02 6.5e-02 1.8e-04 1.2e-04 1.7e-04 2.4e-04 Processing concrete

Cm-244 1.5e-02 8.3e-03 1.5e-02 2.3e-02 5.7e-05 3.1e-05 5.6e-05 8.7e-05 Processing concrete

Cm-245 4.4e-02 2.9e-02 4.3e-02 6.0e-02 1.6e-04 1.1e-04 1.6e-04 2.2e-04 Processing concrete

Cm-246 2.5e-02 1.3e-02 2.5e-02 3.9e-02 9.4e-05 5.0e-05 9.3e-05 1.4e-04 Processing concrete

Cm-247 1.2e-01 6.2e-02 1.1e-01 2.3e-01 4.6e-04 2.3e-04 4.0e-04 8.6e-04 Road building

Cm-248 9.1e-02 4.8e-02 9.0e-02 1.4e-01 3.4e-04 1.8e-04 3.3e-04 5.1e-04 Processing concrete

Bk-249 1.1e-04 5.9e-05 1.1e-04 1.7e-04 4.1e-07 2.2e-07 4.1e-07 6.2e-07 Processing concrete

Cf-248 4.8e-03 2.7e-03 4.7e-03 7.2e-03 1.8e-05 1.0e-05 1.7e-05 2.7e-05 Processing concrete

Cf-249 1.4e-01 9.2e-02 1.4e-01 1.9e-01 5.1e-04 3.4e-04 5.0e-04 7.0e-04 Processing concrete

Cf-250 2.0e-02 1.1e-02 2.0e-02 3.1e-02 7.5e-05 4.0e-05 7.4e-05 1.1e-04 Processing concrete

Cf-251 6.8e-02 4.5e-02 6.8e-02 9.5e-02 2.5e-04 1.7e-04 2.5e-04 3.5e-04 Processing concrete

Cf-252 1.2e-02 6.3e-03 1.1e-02 1.8e-02 4.3e-05 2.3e-05 4.3e-05 6.5e-05 Processing concrete

Cf-254 4.9e+00 2.9e+00 4.8e+00 7.3e+00 1.8e-02 1.1e-02 1.8e-02 2.7e-02 Processing concrete

Es-254 3.1e-01 1.5e-01 2.7e-01 5.9e-01 1.1e-03 5.5e-04 9.9e-04 2.2e-03 Road building

a 5th percentile to 95th percentile = 90% confidence interval
Recycling and Disposal of Concrete Rubble Chapter 6

NUREG-1640 6-26

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Solid Waste Division. http://www.epa.gov/epaoswer/hazwaste/sqg/c&d-rpt.pdf

(December 6, 2002).

Parker, S. P. (Ed.) 1994. McGraw-Hill Dictionary of Scientific and Technical Terms (5th ed.)

New York: McGraw Hill, Inc. 

Riala, R. (n/d). “Good Practices in Controlling Quartz Dust Exposure.”

http://www.ufa.org.se/OSH&D/OSH&D4/4good.html (March 29, 2003).
Chapter 6 Recycling and Disposal of Concrete Rubble

6-27 NUREG-1640

Texas Department of Transportation (TxDOT). 1999. “January: Crushed Concrete.” In “Year of

Recycled Roadway Materials.” ftp://ftp.dot.state.tx.us/pub/txdot-info/gsd/pdf/yrr_jan.pdf

(December 9, 2002).

Turner-Fairbank Highway Research Center (TFHRC). 1997. “User Guidelines for Waste and

Byproduct Materials in Pavement Construction,” FHWA-RD-97-148. 

http://www.tfhrc.gov/hnr20/recycle/waste/begin.htm (December 13, 2002).

U.S. Geological Survey (USGS). 2000. “Recycled Aggregates—Profitable Resource

Conservation,” USGS Fact Sheet FS-181-99.

http://pubs.usgs.gov/fs/fs-0181-99/fs-0181-99po.pdf (April 8, 2003).
Chapter 7 Quality Control Program

7-1 NUREG-1640

In order to ensure that the radiological assessments of the recycling and/or disposal of cleared

materials are defensible, accurate, and verifiable, a Quality Management Plan (QMP) was prepared

and followed during the conduct of this analysis. The QMP includes specification of procedures and

conventions adopted to implement quality control for the present analysis. The QMP also describes

requirements for model development, mathematical analyses, and software implementation, and also

specifically addresses requirements for the preparation, review, verification, documentation, and record

keeping of technical information. The QMP therefore provides a documented system for ensuring

accuracy of results, as well as a basis for tracing calculations. The QMP incorporated quality

assurance guidelines provided by the NRC and other recognized authorities. 

The pathway models developed for this analysis serve as the design descriptions for software

development. A Project Quality Assurance (QA) Manager ensures that appropriate steps are taken to

implement the quality control, documentation and configuration management requirements of the

analyses. The Project Manager acts as a central hub for the review process; all material passes

through the Project Manager at each step of the review and final documentation of technical

information. All technical information developed for the project is independently verified. This includes

conceptual models, equations, and computer software. Specific items to be reviewed are indicated on

the review checklist that accompanied all review packets. In addition to in-house review, the analysis of

each of the four types of cleared material is peer reviewed by two or more outside consultants,

including specialists in probabilistic radiological assessments and experts on the recycling practices for

each material. This peer review ensure the technical adequacy and reasonableness of the analysis,

the interpretation of the results, and that the assumptions reflect current U.S. industrial practices. 

In order to meet the documentation requirements in an organized, retrievable manner, a formal system

of document review and filing has been implemented. The Project Manager is responsible for

maintaining the organization and contents of the Project Engineering Cabinet, which serve as a

repository for the master versions of all controlled project documents.

7 QUALITY CONTROL PROGRAM

As described in Chapter 1, the purpose of the present analysis is to assess the radiological

impacts of the clearance of materials from NRC- and Agreement State-licensed facilities on

members of the public. A defensible assessment must be accurate and verifiable. It must be

supported by a quality assurance record of checks for errors in documentation, calculation, and

transcription. In order to ensure that these elements are incorporated, a Quality Management

Plan (QMP) has been prepared and is followed while conducting this analysis. The QMP is

found in Appendix O. 

The purpose of the QMP is to define responsibilities and to prescribe a process of controls to

ensure the adequacy, completeness, and correctness of technical information and analyses. The

QMP for this project addresses the preparation, review, approval, and revision of conceptual and

mathematical models, computer software, and other technical information. 

As a result of implementing the QMP, the following qualitites of the work products—

deliverables and files—are ensured. A primary objective is to enable an independent review of

all work performed. 

• Transparency. Mathematical formulations and rationales for assumptions and parameter

selections are explicit and complete.
Quality Control Program Chapter 7

NUREG-1640 7-2

• Traceability. Citations of references are complete enough to enable independent retrieval or

copies of cited material are included in the Engineering Design Files.

• Accuracy. Results of calculations are checked for accuracy and consistency with the design

objectives.

• Organization. Records in the Engineering Design Files are logically organized and indexed

to facilitate data retrieval.

• Archives. Sufficient backup of files and work in progress are maintained to guard against

loss due to unexpected events, such as fire or theft. 

The QMP incorporates quality assurance guidelines provided by ASME (1997). Since this

project is not “safety-related” as defined in 10 CFR 50.2, ASME 1997 does not strictly apply,

but is still used to provide general guidance.

Computer software developed as part of this project was developed utilizing the quality

assurance guidance provided by the American Nuclear Society (ANS 1987) and the NRC (1993).

References

American Nuclear Society (ANS). 1987. “Guidelines for the Validation and Verification of

Scientific and Engineering Computer Programs for the Nuclear Industry,” ANSI/ANS-10.4-1987

(R1998) Lagrange Park, IL: Author.

American Society of Mechanical Engineers (ASME). 1997. “Quality Assurance Program

Requirements for Nuclear Facility Applications,” ANSI/ASME NQA-1-1997. New York:

Author.

Code of Federal Regulations, Title 10, Energy, Part 50, “Domestic Licensing of Production and

Utilization Facilities,”“General Provisions,” 50.2 “Definitions.” (10 CFR 50.2) 

Nuclear Regulatory Commission (U.S.) (NRC). 1993. “Software Quality Assurance Program and

Guidelines,” NUREG/BR-0167. Washington, DC: Author.
Glossary Chapter 8

8-1 NUREG-1640

8 GLOSSARY

Several references were consulted in preparing this glossary. Standard dictionaries are not cited

as references. Citations are included in the text only for references that provide a unique

definition of the listed term. Definitions not otherwise attributed are based on one or more of the

listed references or on standard dictionaries. The discipline from which the usage arises is in

italics within square brackets, where it may not be readily apparent, for example, [radiation

protection]. Terms that appear in the body of the definition and are defined elsewhere in this

glossary are in italics.

activity [radiation protection]: The rate of disintegration (transformation) or decay of

radioactive material. The unit of activity is the becquerel (Bq) (10 CFR 20.1003).

activation [radiation protection]: The process of making a radioisotope by bombarding a stable

element with neutrons or protons.

anode: The positive terminal of an electrolytic cell. In the electrolytic refining of copper, the

anode is cast from copper produced by a reverberatory furnace.

areal activity concentration: (Also surficial activity concentration). The total residual activity

of a component of cleared material, divided by the exposed surface area of the component, and

expressed in Bq/cm2.

baghouse [metallurgical industry]: An air pollution control device employed by electric arc

furnaces and many other metal melting and refining furnaces. The baghouse contains rows of

filters, suspended from the ceiling, that trap the particulate emissions from the melting and

refining process. These bag-like filters are shaken at frequent intervals; the dust settles into

collecting hoppers and is fed by a screw mechanism into a tanker trailer. 

basic oxygen furnace (BOF): A pear-shaped furnace, lined with refractory bricks, that refines

molten iron from the blast furnace and scrap into steel. Up to 30% of the charge into the BOF

can be scrap, with hot metal accounting for the rest. BOFs, which can refine a heat (batch) of

steel in less than 45 minutes, replaced open-hearth furnaces in the 1950s—the latter required five

to six hours to process the metal. The BOF's rapid operation, lower cost, and ease of control

give it a distinct advantage over previous methods. Scrap is dumped into the furnace vessel,

followed by the hot metal from the blast furnace. A lance is lowered from above, through which

blows a high-pressure stream of oxygen to cause chemical reactions that separate impurities as

offgas or slag. Once refined, the liquid steel and slag are poured into separate containers.

becquerel (Bq): The unit of radioactive decay, equal to 1 disintegration per second.

blast furnace: A towering cylinder lined with heat-resistant (refractory) bricks, used by

integrated steel mills to smelt iron from its ore. Its name comes from the "blast" of hot air and

gases forced up through the iron ore, coke, and limestone that load the furnace.
Chapter 8 Glossary

NUREG-1640 8-2

brass: Copper base alloys in which zinc is the principal alloying element. Brass is harder and

mechanically stronger than either of its alloying elements: copper and zinc. It is formable and

ductile, develops high tensile strength with cold-working, but is not heat treatable. 

bremsstrahlung: Secondary photon radiation produced by decelaration of electrically charged

particles passing through matter.

bronze: Primarily an alloy of copper and tin, but additionally, the name is used when referring

to other alloys not containing tin, for example, aluminum bronze, manganese bronze, and

beryllium bronze.

busheling [metallurgical industry]: Steel scrap consisting of sheet clips and stampings from

metal production. This term arose from the practice of collecting the material in bushel baskets

through World War II.

capacity [metallurgical industry]: Normal ability to produce an amount metal in a given time

period. This rating should include maintenance requirements, but because such service is

scheduled to match the needs of the machinery (not those of the calendar), a mill, foundry, or

smelter might run at more than 100% of capacity one month and then fall well below rated

capacity as maintenance is performed.

carbon steel: Steel containing carbon as its principal alloying element. Most of the steel

produced in the world is carbon steel.

cast iron: A hard, brittle non-malleable iron-carbon alloy containing 2.0% to 4.5% carbon,

0.5% to 3% silicon, lesser amounts of sulfur, manganese, and phosphorus.

cast steel: Steel in the form of castings, usually containing less than 2% carbon.

casting [metallurgical industry]: Pouring molten metal into a mold to produce an object of

desired shape.

charge [metallurgical industry]: 1. The act of loading material into a vessel. For example, iron

ore, coke, and limestone are charged into a blast furnace; a basic oxygen furnace is charged with

scrap and hot metal. 2. The material introduced into a furnace for melting.

clear [regulation]: To implement clearance.

clearance [regulation]: The removal of radiological controls by the licensing

authority–in this case the U.S. Nuclear Regulatory Commission.

cleared material [regulation]: Material that has been removed from radiological

regulatory control.
Glossary Chapter 8

8-3 NUREG-1640

coefficient of variability: (Also “coefficient of variation.”) The ratio of the standard deviation

of a distribution to its arithmetic mean.

confidence interval: The lower and upper end points of an interval from a distribution. For

example, the interval from the 5th-percentile value to the 95th-percentile value is a “90%

confidence interval” because it contains 90% of the estimated values in the distribution (95%

minus 5%).

continuous casting [metallurgical industry]: A method of pouring steel directly from the

furnace into a billet, bloom, or slab directly from its molten form. Continuous casting avoids the

need for large, expensive mills for rolling ingots into slabs. Continuous cast slabs also solidify

in a few minutes versus several hours for an ingot. Because of this, the chemical composition

and mechanical properties are more uniform. Steel from the BOF or electric furnace is poured

into a tundish atop the continuous caster. As steel is carefully allowed to flow from the tundish

down into the water-cooled copper mold of the caster, it solidifies into a ribbon of red-hot steel. 

At the bottom of the caster, torches cut the continuously flowing steel to form slabs or blooms.

critical group: The group of individuals reasonably expected to receive the greatest exposure to

residual radioactivity for any applicable set of circumstances (10 CFR 20.1003). 

deterministic: A model whose output is predetermined by the mathematical form of its

equations and the selection of a single value for each input parameter (NCRP 1984).

direct reduced iron (DRI): Processed iron ore that is iron-rich enough to be used as a scrap

substitute in electric furnace steelmaking. As mini-mills expand their product abilities to sheet

steel, they require much higher grades of scrap to approach integrated mill quality. Enabling the

mini-mills to use iron ore without the blast furnace, DRI can serve as a low residual raw material

and alleviate the mini-mills' dependence on cleaner, higher-priced scrap. The impurities in the

crushed iron ore are driven off through the use of massive amounts of natural gas. While the

result is 97% pure iron (compared with blast furnace hot metal, which, because it is saturated

with carbon, is only 93% iron), DRI is only economically feasible in regions where natural gas is

attractively priced.

dose [radiation protection]: A generic term that means absorbed dose, dose equivalent, effective

dose, or effective dose equivalent.

dose coefficient (external): A set of coefficients that relate the exposure of an individual

standing on soil contaminated with a given radionuclide to either the effective dose or effective

dose equivalent (EDE). The EDE-external exposure dose coefficients used in the present

analysis were taken from Federal Guidance Report No. 12 (Eckerman and Ryman 1993), while

the effective dose coefficients were from EPA 2000.

dose coefficient (intake): A set of coefficients that relate the intake of a unit activity of a given

radionuclide in a given chemical form to the 50-year committed effective dose. In the present

report, the terms “committed effective dose” and effective dose are synonymous. The dose
Chapter 8 Glossary

NUREG-1640 8-4

coefficients in the present analysis are based on the values tabulated in “ICRP Publication 68"

(ICRP 1994). Separate dose coefficients are tabulated for the inhalation and ingestion pathways. 

In addition, there are separate coefficients for the inhalation of 1 :m and 5 :m particles.

dose conversion factor (DCF): More accurately “exposure-to-dose conversion factor.” A set of

factors that relate the intake of a unit activity of a given radionuclide in a given chemical form to

the 50-year committed effective dose equivalent. In the present report, the terms “committed

effective dose equivalent” and effective dose equivalent are synonymous. The DCFs in the

present analysis are based on the values tabulated in Federal Guidance Report No. 11 (Eckerman

et al. 1988). Separate DCFs are tabulated for the inhalation and ingestion pathways.

dose equivalent (HT): The product of the absorbed dose in tissue, quality factor, and all other

necessary modifying factors at the location of interest. The units of dose equivalent are the rem

and sievert (Sv) (10 CFR 20.1003)

dross [metallurgical industry]: An impurity, usually an oxide, formed on the surface of a molten

metal; especially in melt-refining of secondary aluminum. Aluminum dross contains aluminum

oxide, halide salts, and metallic aluminum.

effective dose: , where wT is a weighting factor and HT is the mean dose

equivalent to organ or tissue T. The factor wT, normalized so that , corresponds to the

fractional contribution of organ or tissue T to the total risk of stochastic effects when the body is

uniformly irradiated. For the purposes of radiological protection calculations, the human body is

defined in “ICRP Publication 60" (ICRP 1991) by 12 designated tissues and organs, and the

“remainder,” which consists of 10 additional tissues and organs. Recommended weighting

factors, which apply to a human adult population for these tissues and organs, are given in

“ICRP Publication 60.” (ICRP 1996)

effective dose equivalent (EDE): , where w1T represents the set of weighting

factors specified in “ICRP Publication 26" (ICRP 1977). These weighting factors are specified

for six organs and a composite set of five remaining organs, designated as the “remainder.” 

Except for the difference in the weighting factors, the definitions of effective dose and effective

dose equivalent are quite similar.

electric arc furnace (EAF): Steelmaking furnace where scrap constitutes up to 100% of the

charge. Heat is supplied from electricity that arcs from the graphite electrodes to the metal bath. 

Furnaces may be either an alternating current or direct current. Direct current units consume less

energy and fewer electrodes, but they are more expensive.

exposure [radiation protection]: Being exposed to ionizing radiation or to radioactive material

(10 CFR 20.1003).
Glossary Chapter 8

8-5 NUREG-1640

exposure scenario: The set of circumstances that define a potential situation that could result in

a radiation exposure of an individual or a group of individuals. Exposure scenarios are used to

model potential doses resulting from the recycling and disposal of cleared material.

extrusion [metallurgical industry]: Shaping metal into a chosen continuous form by forcing it

through a die of appropriate shape.

ferrous: Related to iron (derived from the Latin ferrum). Ferrous alloys are iron base alloys.

flux [metallurgical industry]: An iron cleaning agent. Limestone and lime react with impurities

within the metallic pool to form a slag that floats to the top of the relatively heavier (and now

purer) liquid iron.

free-machining steel [metallurgical industry]: Steel to which impurities have been added to

improve machinability.

galvanized steel [metallurgical industry]: Steel coated with zinc to provide corrosion resistance

for a wide range of products, including automobiles, bridges, storage tanks, structural steel,

fasteners, duct work, light poles, pipe, sign supports, reinforcing steel and wire.

heat [metallurgical industry]: A single heating, melting, or smelting operation, as in working

iron or steel; also, the material heated, melted, etc., at one time.

home scrap [metallurgical industry]: Scrap generated during processing and consumed in the

same plant where generated. 

hot metal [metallurgical industry]: The molten iron produced in a blast furnace. It proceeds to

the basic oxygen furnace in molten form or is cast as pig iron.

induction furnace [metallurgical industry]: An electric furnace in which heat is produced in a

metal charge by electromagnetic induction.

ingot [metallurgical industry]: A solid metal casting suitable for remelting or working.

integrated mills [metallurgical industry]: Facilities that make steel by processing iron ore and

other raw materials in blast furnaces. Technically, only the hot end differentiates integrated

mills from mini-mills. However, the differing technological approaches to molten steel imply

different scale efficiencies and, therefore, separate management styles, labor relations and

product markets. Nearly all domestic integrated mills specialize in flat-rolled steel or plate.

mean (arithmetic): The arithmetic average of a population—i.e., the sum of all of the values in

the population divided by the number in the population.

median: The value in a distribution such that half of the values are bigger, and half of the values

are smaller.
Chapter 8 Glossary

NUREG-1640 8-6

mini-mills [metallurgical industry]: Normally defined as steel mills that melt scrap metal to

produce commodity products. Although the mini-mills are subject to the same steel processing

requirements after the caster as the integrated steel companies, they differ greatly in regard to

their minimum efficient size, labor relations, product markets, and management style.

model: A mathematical abstraction of an ecological or biological system, sometimes including

specific numerical values for the parameters of the system (NCRP 1984).

new scrap [metallurgical industry]: Scrap produced during the manufacture of metals and

articles for immediate and ultimate consumption; this includes all defective finished and

semifinished articles that must be reworked. Examples of new scrap are borings, castings,

clippings, drosses, skims and turnings. New scrap includes scrap generated at facilities that

consume old scrap. Included as new scrap is prompt industrial scrap – scarp obtained from a

facility separate from the recycling refiner, smelter, or processor. Excluded from new scrap is

home scrap that is generated as process scrap and used at the same plant.

No. 1 heavy melt [metallurgical industry]: Obsolete steel scrap grade, at least one-quarter inch

(~0.6 cm) in thickness and in sections no larger than five feet by two feet (~1.5 m × 0.6 m). 

Much of the metal comes from demolished buildings, truck frames and heavy duty springs. 

Mini-mills are primary consumers of No. 1 heavy scrap.

nuclide: A species of atom characterized by the number of protons, neutrons, and energy level

of the nucleus. A nuclide can be stable or radioactive (see radionuclide).

offgas [metallurgical industry]: The gases, vapors, and particulates that evolve from a furnace

during the melting and refining of metals.

old scrap [metallurgical industry]: Scrap that includes, but is not limited to, articles that have

been discarded after serving a useful purpose. Typical examples of old scrap are electrical

wiring, lead-acid batteries, metals from shredded cars and appliances, silver from photographic

materials, spent catalysts, tool bits, and aluminum beverage cans. This is also referred to as

“postconsumer scrap” and may originate from industry or the general public. Expended or

obsolete materials used dissipatively, such as paint and fertilizer, are not included.

oxygen lance [metallurgical industry]: A length of pipe used to convey oxygen onto a bath of

molten metal.

parameter: Any one of a set of variables in a model whose values determine model predictions. 

(Till and Meyer 1983).

particulates: Fine solid particles which remain individually dispersed in gases or stack

emissions.
Glossary Chapter 8

8-7 NUREG-1640

partitioning [metallurgical industry]: The redistribution of impurities in the furnace charge

among furnace products during melting. The impurities are distributed among molten metal,

slag or dross, dust, and volatile vapors or gases.

partitioning factor [metallurgical industry]: The ratio of the total amount of a given element or

compound in one of the furnace products to the amount in the scrap metal charged to the

furnace.

percentile: The value in a distribution such that the given fraction (percentage) of values are less

than that value. For example, 95% of the values in a distribution are less than the 95th-percentile

value.

pig iron [metallurgical industry]: The name for the melted iron produced in a blast furnace,

containing a large quantity of carbon (above 1.5%). Named long ago when molten iron was

poured through a trench in the ground to flow into shallow earthen holes, the arrangement looked

like newborn pigs suckling. The central channel became known as the "sow," and the molds

were "pigs."

poling [metallurgical industry]: Insertion of wood poles into a molten metal bath [of copper],

producing a reducing atmosphere by destructive distillation.

progeny [radiation protection]: The nuclide or nuclides resulting from the radioactive

disintegration of a radionuclide, formed either directly or as the result of successive

transformations in a radioactive series. Progeny may be either radioactive or stable.

Q-BOP [metallurgical industry]: Modified basic oxygen furnace in which the oxygen and other

gases are blown in from the bottom, rather than from the top. While the Q-BOP stirs the metal

bath more vigorously, allowing for faster processing, the design produces essentially the same

steel grades as the top-blowing basic oxygen furnace. Today's state-of-the-art furnace design

combines the previous technologies: 60% of the oxygen is blown from above, with the rest

blown through the bottom of the vessel.

radiation [radiation protection]: Alpha particles, beta particles, gamma rays, x-rays, neutrons,

high-speed electrons, high-speed protons, and other particles capable of producing ions.

Radiation, as used in this report, does not include non-ionizing radiation, such as radio or

microwaves, or visible, infrared, or ultraviolet light. 

radionuclide: An atom that, due to its atomic instability, undergoes spontaneous nuclear

disintegration. Nuclear disintegration is accompanied by the emission of electrically charged

particles or photons, and results in the formation of another, distinct atom (see progeny).

radionuclide-dependent parameter: A parameter whose value is specific to a given

radionuclide, and therefore may be different for different radionuclides. 
Chapter 8 Glossary

NUREG-1640 8-8

radionuclide-independent parameter: A parameter whose value is not specific to any

radionuclide.

realistic: Typical of a real-life situation, and therefore likely to be observed in real life. An

accurate representation of a reasonably foreseeable, real-life situation.

refractory brick: Heat-resistant brick. Because its melting point is well above the operating

temperatures of the process, refractory bricks line most steelmaking vessels that come in contact

with molten metal, like the walls of the blast furnace, sides of the ladles, and inside of the BOF.

residual radioactivity: Radioactivity in structures, materials, soils, groundwater, and other

media at a site resulting from activities under the control of an NRC-licensee. This includes

radioactivity from all licensed and unlicensed sources used by the licensee, but excludes

background radiation (10 CFR 20.1003).

reverberatory furnace [metallurgical industry]: A furnace in which heat is supplied by

burning of fuel between the charge and the low roof.

scale [metallurgical industry]: A layer of oxidation products formed on a metal at high

temperature.

secondary ingestion: Accidental or unintentional ingestion of material (also sometimes referred

to as “inadvertent ingestion”). In this analysis, secondary ingestion applies to the unintentional

ingestion of soil, dust, or other particulate matter.

sensitivity: The mathematical sensitivity of the model predictions to selected perturbations of

model parameters (NCRP 1984).

sensitivity analysis: Identification of the relative contribution of the uncertainty in a given

model component to the total uncertainty in the model result (NCRP 1996).

shaft furnace [metallurgical industry]: A vertical, refractory-lined cylinder in which a fixed bed

(or descending column) of solids is maintained and through which an ascending stream of hot

gases is forced.

sheet steel [metallurgical industry]: Thin, flat-rolled steel. Coiled sheet steel accounts for

nearly one-half of all steel shipped domestically and is created in a hot-strip mill by rolling a cast

slab flat while maintaining the side dimensions. The malleable steel lengthens to several

hundred feet (100s of meters) as it is squeezed by the rolling mill. The most common

differences among steel bars, strip, plate, and sheet are merely their physical dimensions of

width and gauge (thickness).

sinter [metallurgical industry]: Baked particles that stick together in roughly one-inch (~2.5 cm)

chunks. Normally used for iron ore dust collected from the blast furnaces.
Glossary Chapter 8

8-9 NUREG-1640

slab [metallurgical industry]: A piece of metal, intermediate between ingot and plate, at least

twice as wide as it is thick.

slag [metallurgical industry]: A nonmetallic product resulting from the mutual dissolution of

flux and nonmetallic impurities in smelting and refining operations; the impurities in a molten

pool of iron. Flux such as limestone may be added to foster the congregation of undesired

elements into a slag. Because slag is lighter than iron, it will float on top of the pool, where it

can be skimmed.

specialty steel [metallurgical industry]: Category of steel that includes electrical, alloy, stainless

(see stainless steel) and tool steels.

specific activity: (Also mass activity concentration). The total residual radioactivity of a

component of cleared material, divided by the mass of the component, and expressed in Bq/g.

stainless steel: The term for grades of steel that contain more than 10% chromium, with or

without other alloying elements. Stainless steel resists corrosion, maintains its strength at high

temperatures, and is easily maintained. For these reasons, it is used widely in items such as

automotive and food processing products, as well as medical and health equipment.

standard deviation: The positive square root of the expected value of the square of the

differences between a random variable and its mean.

tapping [metallurgical industry]: Transferring molten metal from melting furnace to ladle.

tundish [metallurgical industry]: The shallow refractory-lined basin on top of the continuous

caster. It receives the liquid steel from the ladle, prior to the cast, allowing the operator to

precisely regulate the flow of metal into the mold. 

uncertainty: The lack of sureness or confidence in the predictions of models (NCRP 1984).

uniform distribution: A distribution of values such that all values are equally likely to occur, or

alternatively, equally likely to be sampled during conduct of an uncertainty analysis.

vadose zone (unsaturated zone): The portion of porous media in the ground where the

interconnecting interstices are only partially filled with fluid (NCRP 1984)

wirebar [metallurgical industry]: Cast copper ingots used in the manufacture of wire.
Chapter 8 Glossary

NUREG-1640 8-10

References

Code of Federal Regulations, Title 10, Energy, Part 20, “Standards for Protection Against

Radiation,” Subpart A, “General Provisions,” 20.1003 “Definitions,” (10 CFR 20.1003).

http://www.nrc.gov/reading-rm/doc-collections/cfr/part020/full-text.html (May 2, 2003).

Eckerman, K. F., A. B. Wolbarst, and A. C. B. Richardson. 1988. “Limiting Values of

Radionuclide Intake and Air Concentration and Dose Conversion Factors for Inhalation,

Submersion, and Ingestion,” Federal Guidance Report No. 11, EPA-520/1-88-020.

Washington, DC: U.S. Environmental Protection Agency, Office of Radiation Programs.

Eckerman, K. F., and J. C. Ryman. 1993. “External Exposure to Radionuclides in Air, Water,

and Soil,” Federal Guidance Report No. 12, EPA 402-R-93-081. Washington, DC: U.S.

Environmental Protection Agency, Office of Radiation and Indoor Air.

Environmental Protection Agency (U.S.) (EPA). 1977. “Emission Factors and Emission Source

Information for Primary and Secondary Copper Smelters,” EPA-450/3-77-051. Research

Triangle Park, NC: Author.

Environmental Protection Agency (U.S.) (EPA). 2000. “Federal Guidance Report 13: Cancer

Risk Coefficients for Environmental Exposures to Radionuclides.” CD Supplement,

EPA-402-C-99-001. Washington DC: Author.

Fenton, M. D. 2001. “Iron and Steel Recycling in the United States in 1998,” Open File Report

01-224. U.S. Geological Survey. http://pubs.usgs.gov/of/of01-224/of01-224.pdf (June 11, 2003).

International Commission on Radiological Protection (ICRP). 1977. “Recommendations of the

ICRP,” ICRP Publication 26. Annals of the ICRP, 1(3). Oxford: Pergamon Press.

International Commission on Radiological Protection (ICRP). 1991. “1990 Recommendations of

the ICRP,” ICRP Publication 60. Annals of the ICRP, 21(1-3). Oxford: Pergamon Press.

International Commission on Radiological Protection (ICRP). 1994. “Dose Coefficients for

Intakes of Radionuclides by Workers,” ICRP Publication 68. Annals of the ICRP, 24(4). 

Tarrytown, NY: Elsevier Science, Inc.

International Commission on Radiological Protection (ICRP). 1996. “Conversion Coefficients

for Use in Radiological Protection Against External Radiation,” ICRP Publication 74. Annals of

the ICRP, 26(3/4). Tarrytown, NY: Elsevier Science, Inc.

National Council on Radiation Protection and Measurements (NCRP). 1984. “Radiological

Assessment: Predicting the Transport, Bioaccumulation, and Uptake by Man of Radionuclides

Released to the Environment,” NCRP Report No. 76. Bethesda, MD: Author. 
Glossary Chapter 8

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National Council on Radiation Protection and Measurements (NCRP). 1996. “NCRP

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