Clinton Engineer Works

Special Exposure Cohort 

Petition Evaluation Report

James W. Neton, PhD, CHP

Associate Director for Science

National Institute for Occupational Safety and Health

Division of Compensation Analysis and Support

February 2012

Oakland, CA
Petition Overview

 Petition received on July 28, 2010

 Petitioner proposed class definition:

• All guards and service workers who worked in 

any area at Clinton Engineer Works from 

January 1, 1943 through May 18, 1947

 Covered period for the Clinton Engineer 

Works (CEW) is from 1943 to 1949
Petition Overview—cont. 

 Petition qualified for evaluation on October 20, 

2010

 Affidavit provided by survivor in support of the 

petition basis indicated:

• Employees were not monitored

 The class evaluated by NIOSH: 

• All guards and service workers who worked in or around 

the warehouses at the Elza Gate area of Clinton Engineer 

Works from January 1, 1943 through December 31, 1949
Petition Overview—cont.

 NIOSH proposed class to be added to the SEC:

All employees of the Tennessee Eastman Corporation 

(1943-1947) and the Carbide and Carbon Chemicals 

Corporation (1947-1949) who were employed at the 

Clinton Engineer Works in Oak Ridge, Tennessee, from 

January 1, 1943 through December 31, 1949 for a 

number of work days aggregating at least 250 work days, 

occurring either solely under this employment or in 

combination with work days within the parameters 

established for one or more classes of employees 

included in the Special Exposure Cohort
Background

 CEW is located in the Oak Ridge Area of TN, 

consisting of ~ 59,000 acres and encompasses Y-12, 

X-10, and K-25 facilities and the community of Oak 

Ridge

 CEW site is about 17 miles long and 9 miles wide at 

their greatest width and length, respectively

 City of Oak Ridge occupied approximately 8 square 

miles in the northeast corner of CEW

 EEOICPA covered facility of CEW does not include 

the separately covered sites within the CEW 

boundary
Map of CEW
Background: Elza Gate Warehouse Area

 20-acre site with five warehouses used for storage of 

radioactive materials

 Located near the Elza entrance gate to Oak Ridge

 The warehouses are the only buildings within CEW 

where radioactive materials are known to have been 

stored or handled during the CEW covered period

 Workforce of warehouses provided by Y-12 contractors 

Tennessee Eastman Corporation through 1947 and 

Carbon and Carbide Chemicals Corporation thereafter
Background: Elza Gate Warehouse Site
Background: Stored Materials

 High- and low-grade uranium ores from Africa

 Slag and residues from uranium processing to be 

shipped back to African Metals

 Various radioactive materials and surplus 

equipment parts from the operation of Y-12
Previous Dose Reconstructions

NIOSH OCAS Claims Tracking System 

Information available as of January 25, 2012

• CEW claims submitted to NIOSH 38

• Claims that meet the class definition 34

• Dose reconstructions completed for claims 27

that meet the class definition 

Cases with a PoC > 50% 5

Cases with a PoC < 50% 22

• Claims containing internal dosimetry 0 

• Claims containing external dosimetry 0
Sources of Available Information

 ORAU Team Technical Information Bulletins 

(TIBs) and Procedures

 Interviews with two individuals knowledgeable 

about Oak Ridge history

 Existing claimant files

 Documentation provided by petitioner

 NIOSH Site Research Database

 Data capture
Data Capture Efforts

 DOE Opennet (OSTI database)

 Internet search

 DOE Comprehensive Epidemiological Data 

Resource (CEDR)

 NARA Atlanta

 Oak Ridge Operations Office
External and Internal Sources 

of Exposure

 Direct radiation from handling or working near 

the ore and tailings

 Inhalation of radon and radon decay products

 Dust inhalation and ingestion from handling 

ore and slag materials (e.g., loading, 

unloading, and re-bagging dry materials)
External Sources of Exposure

 Photons

• Uranium and progeny

• Radium, radon and shortlived progeny

 Beta

• Uranium progeny (protactinium)
Internal Sources of Exposure

 Uranium and progeny

 Radium and radon and its short-lived progeny
Available Internal Monitoring Data

 Various radon in air samples from 1944 and 

1945, some before and after installation of 

ventilation equipment

 There is no information that workers at the Elza 

Gate warehouses were undergoing bioassay 

sampling

 No internal monitoring data has been found
Available External Monitoring Data

 Film badge data available for a limited number of 

workers and time periods (1945 and 1946 only)

 University of Rochester provided film badge 

service

 Limited number of area gamma surveys from 1944 

and 1945
Feasibility of Dose Reconstruction

 There are insufficient monitoring and 

source-term data from which to draw 

conclusions regarding potential magnitude of 

internal and external doses for the period from 

January 1, 1943 through December 31, 1949

• Limited film badge data available

• Lack of radon, air sampling, and personal bioassay for 

uranium progeny through 1949

• Inconsistent source-term and varied unknown 

activities prevent modeling or using surrogate data
Summary of Feasibility Findings

Sources of Exposure

January 1, 1943 – December 31, 1949

DR Feasible DR Not Feasible

Internal X

Radon X

Uranium X

Radium X

Thorium X

External X

Gamma X

Beta X

Neutron NA NA

X-ray X
Health Endangerment

 The evidence reviewed in this evaluation 

indicates that some workers in the class may 

have accumulated chronic radiation exposures 

through intakes of radionuclides and direct 

exposure to radioactive materials

 Consequently, NIOSH is specifying that health 

may have been endangered for those workers 

covered by this evaluation who were employed 

for a number of work days aggregating at least 

250 work days within the parameters 

established for this class or in combination with 

work days within the parameters established for 

one or more other classes of employees in the 

SEC 
Proposed Class

All employees of the Tennessee Eastman 

Corporation (1943-1947) and the Carbide and 

Carbon Chemicals Corporation (1947-1949) who 

were employed at the Clinton Engineer Works in 

Oak Ridge, Tennessee, from January 1, 1943 

through December 31, 1949 for a number of 

work days aggregating at least 250 work days, 

occurring either solely under this employment or 

in combination with work days within the 

parameters established for one or more classes 

of employees included in the Special Exposure 

Cohort
Recommendation

 For the period January 1, 1943 – December 31, 

1949, NIOSH finds that radiation dose estimates 

cannot be reconstructed for compensation 

purposes

Class Feasibility Health 

Endangerment

January 1, 1943 –

December 31, 1949 No Yes