ORAU TEAM

Dose Reconstruction

Project for NIOSH

Oak Ridge Associated Universities I Dade Moeller I MJW Technical Services

Page 1 of 40

DOE Review Release 03/02/2011

Document Title:

Parameters to Consider When Processing 

Claims for Construction Trade Workers

Document Number: ORAUT-OTIB-0052

Revision: 01

Effective Date: 02/17/2011

Type of Document: OTIB

Supersedes: Revision 00 PC-1

Subject Expert(s): Melton H. Chew, John A. Devanney, Leo G. Faust, Robert L. Morris, and Eugene W. 

Potter

Site Expert(s): N/A

Approval: Signature on File Approval Date: 02/14/2011

Matthew H. Smith, Document Owner

Concurrence: Signature on File Concurrence Date: 02/14/2011

John M. Byrne, Objective 1 Manager

Concurrence: Signature on File Concurrence Date: 02/14/2011

Edward F. Maher, Objective 3 Manager

Concurrence: Signature on File Concurrence Date: 02/16/2011

Kate Kimpan, Project Director

Approval: Signature on File Approval Date: 02/17/2011

James W. Neton, Associate Director for Science

New Total Rewrite Revision Page Change

FOR DOCUMENTS MARKED AS A TOTAL REWRITE, REVISION, OR PAGE CHANGE, REPLACE THE PRIOR 

REVISION AND DISCARD / DESTROY ALL COPIES OF THE PRIOR REVISION.
Document No. ORAUT-OTIB-0052 Revision No. 01 Effective Date: 02/17/2011 Page 2 of 40

PUBLICATION RECORD

EFFECTIVE 

DATE

REVISION 

NUMBER DESCRIPTION

08/31/2006 00 First approved issue. New document to describe the parameters to 

consider when processing claims for CTWs. Incorporates formal 

internal review comments and comments from the Worker Outreach 

meetings with the Hanford PACE Local (Steelworkers and Guards) 

on 05/22/2005 and the Central Washington Building and 

Construction Trades Council on 01/15/2005. Revised to incorporate 

additional NIOSH comments. There is an increase in assigned dose 

and a PER is required. Training required: As determined by the 

Task Manager. Initiated by Melton H. Chew and John A. Devanney.

01/16/2007 00 PC-1 Sections 8.2, 8.3, and 8.4 on pages 32 and 33 revised in order to 

provide consistent guidance for dose reconstruction. No sections 

were deleted. Incorporates internal formal review comments. No 

changes were needed as a result of NIOSH formal review. This 

revision does not result in an increase of dose and no PER is 

required. Training required: As determined by the Task Manager. 

Initiated by John M. Byrne. Approval:

John M. Byrne, Document Owner

Signature on File 12/19/2006

Signature on File

Edward F. Maher, Task 5 Manager

12/18/2006

Kate Kimpan, Project Director

Signature on File 01/11/2007

James W. Neton, Associate Director for Science

Brant A. Ulsh Signature on File for 01/16/2007

02/17/2011 01 The Advisory Board tasked SC&A to review OTIB-0052 Rev 00 

PC-1. A draft report and sixteen findings were produced. Eight 

findings were closed after discussion in the Procedures Review 

Working Group, three were transferred to another Working Group, 

and five ("in abeyance") are closed by this revision. These changes 

clarify the basis for certain assumptions and provide cautions 

regarding the limitations of the available data. Incorporates formal 

internal and NIOSH review comments. Constitutes a total rewrite of 

the document. Training required: As determined by the Objective 

Manager. Initiated by Melton H. Chew and Matthew H. Smith. 
Document No. ORAUT-OTIB-0052 Revision No. 01 Effective Date: 02/17/2011 Page 3 of 40

TABLE OF CONTENTS

SECTION TITLE

Acronyms and Abbreviations ...............................................................................................................

PAGE

5

1.0 Introduction ..............................................................................................................................7

2.0 Purpose ...................................................................................................................................8

3.0 Scope.......................................................................................................................................8

3.1 Limitations and Exceptions ...........................................................................................9

4.0 Sources of Data .......................................................................................................................9

4.1 General Description of External Dose Data ..................................................................9

4.2 General Description of the Adjustment Factor ..............................................................9

4.3 General Description of Bioassay Data Used for Internal Dose.................................... 10

4.4 General Description of Nonpenetrating Dose Data .....................................................10

5.0 Comparison of CTW and AMW Doses ................................................................................... 10

5.1 SRS Penetrating Dose Comparison............................................................................11

5.2 SRS Internal Dose Comparison..................................................................................12

5.3 SRS Nonpenetrating Dose Comparison .....................................................................13

5.4 Rocky Flats Plant Penetrating Dose Comparison .......................................................14

5.5 Rocky Flats Plant Internal Dose Comparison..............................................................15

5.6 Rocky Flats Plant Nonpenetrating Dose Comparison .................................................18

5.7 Y-12 Plant Penetrating Dose Comparison ..................................................................19

5.8 Y-12 Plant Internal Dose Comparison.........................................................................20

5.9 K-25 Penetrating Dose Comparison ...........................................................................22

5.10 K-25 Internal Dose Comparison..................................................................................22

5.11 ORNL Penetrating Dose Comparison.........................................................................24

5.12 ORNL Internal Dose Comparison ...............................................................................25

5.13 INL Penetrating Dose Comparison .............................................................................28

5.14 INL Internal and Nonpenetrating Dose Comparison....................................................29

6.0 Hanford Site...........................................................................................................................29

6.1 Hanford Site Penetrating Dose Comparison ...............................................................29

6.2 Hanford Site Internal Dose Comparison .....................................................................31

7.0 Conclusions ...........................................................................................................................33

7.1 Prescribed External Adjustment Factor for All DOE Facilities ..................................... 34

8.0 Limitations and Applications................................................................................................... 34

8.1 Limitations ..................................................................................................................34

8.2 Guidance on the Determination of Penetrating Dose for Unmonitored 

Construction Trade Workers.......................................................................................34

8.3 Guidance on the Determination of Nonpenetrating Dose for Unmonitored 

Construction Trade Workers.......................................................................................35

8.4 Guidance on the Determination of Internal Dose ........................................................35

8.5 Guidance on the Determination of Occupational Medical Dose .................................. 35

9.0 Attributions and Annotations .................................................................................................. 36
Document No. ORAUT-OTIB-0052 Revision No. 01 Effective Date: 02/17/2011 Page 4 of 40

References ........................................................................................................................................38

LIST OF TABLES

TABLE TITLE

5-1 Observed ratios for SRS ........................................................................................................

PAGE

12

5-2 Observed ratios for Rocky Flats ............................................................................................. 15

5-3 Observed ratios for ORNL...................................................................................................... 25

5-4 Observed ratios for INL .......................................................................................................... 29

6-1 Observed ratios and average penetrating dose for CTWs and AMWs at Hanford .................. 31

LIST OF FIGURES

FIGURE TITLE

5-1 95th-percentile annual penetrating dose for CTWs and AMWs for the DOE 

complex .................................................................................................................................

PAGE

11

5-2 95th-percentile penetrating dose for SRS............................................................................... 12

5-3 Results of bioassay samples above the reporting level for randomly selected 

CTWs and non-CTWs at SRS................................................................................................ 13

5-4 95th-percentile nonpenetrating dose for SRS......................................................................... 14

5-5 95th-percentile penetrating dose for Rocky Flats ................................................................... 15

5-6 50th-percentile plutonium in urine for Rocky Flats.................................................................. 17

5-7 84th-percentile plutonium in urine for Rocky Flats.................................................................. 18

5-8 95th-percentile nonpenetrating dose for Rocky Flats.............................................................. 19

5-9 95th-percentile penetrating dose for Y-12 .............................................................................. 20

5-10 50th-percentile uranium in urine for Y-12 ............................................................................... 21

5-11 84th-percentile uranium in urine for Y-12 ............................................................................... 21

5-12 95th-percentile penetrating dose for K-25 .............................................................................. 22

5-13 50th-percentile uranium in urine for K-25 ............................................................................... 23

5-14 84th-percentile uranium in urine for K-25 ............................................................................... 23

5-15 95th-percentile penetrating dose for ORNL ............................................................................ 24

5-16 50th-percentile plutonium in urine for ORNL........................................................................... 26

5-17 84th-percentile plutonium in urine for ORNL........................................................................... 26

5-18 50th-percentile uranium in urine for ORNL ............................................................................. 27

5-19 84th-percentile uranium in urine for ORNL ............................................................................. 27

5-20 Mean value for penetrating dose for INL ................................................................................ 28

6-1 Average annual penetrating dose for Hanford........................................................................ 31

6-2 50th-percentile for Pu-239 in urine for Hanford....................................................................... 33

6-3 84th-percentile for Pu-239 in urine for Hanford....................................................................... 33
Document No. ORAUT-OTIB-0052 Revision No. 01 Effective Date: 02/17/2011 Page 5 of 40

ACRONYMS AND ABBREVIATIONS

AMW all monitored workers

CER Center for Epidemiologic Research (database)

CTW construction trade worker

d day

DOE U.S Department of Energy

dpm disintegrations per minute

GSD geometric standard deviation

HPAREH Health Protection Annual Radiation Exposure History (database)

INL Idaho National Laboratory

M&O Management and Operations

mL milliliter

mrem millirem

NIOSH National Institute for Occupational Safety and Health

ORISE Oak Ridge Institute for Science and Education

ORNL Oak Ridge National Laboratory

PFG photofluorography

REMS Radiation Exposure Monitoring System (database)

SRS Savannah River Site

TBD technical basis document

TIB Technical Information Bulletin

U.S.C. United States Code

yr year
Document No. ORAUT-OTIB-0052 Revision No. 01 Effective Date: 02/17/2011 Page 6 of 40

EXECUTIVE SUMMARY

This document provides guidance for performing dose reconstructions for unmonitored construction 

trade workers (CTWs).

An investigation of the U.S. Department of Energy (DOE) complex was conducted to determine the 

ratio of the external and internal annual doses received by CTWs to those received by all other 

monitored workers (AMWs). In general, it was found that for the DOE complex the internal and 

external annual doses received by the CTWs were usually bounded by those received by the AMWs. 

Examination of the individual DOE sites indicated that in some instances, at some sites, the external 

annual doses received by the CTWs exceeded those of AMWs. In these instances, the observed 

ratios of CTWs’ to AMWs’ external doses were further examined. This resulted in the development of 

a favorable to claimant adjustment factor of 1.4, which will be applied by dose reconstructors to all 

unmonitored CTWs throughout the DOE complex. Guidance is provided for dose reconstructors on 

the use of this adjustment factor.

Examination of the individual DOE sites for internal dose indicated that only the Hanford Site required 

adjustment. For the Hanford Site, the intake rates in the Hanford coworker study should be multiplied 

by a factor of 2. Guidance is provided for dose reconstructors on the determination of internal dose.
Document No. ORAUT-OTIB-0052 Revision No. 01 Effective Date: 02/17/2011 Page 7 of 40

1.0

Technical Information Bulletins (TIBs) are not official determinations made by the National Institute for 

Occupational Safety and Health (NIOSH) but are rather general working documents that provide 

historic background information and guidance to assist in the preparation of dose reconstructions at 

particular sites or categories of sites. They will be revised in the event additional relevant information 

is obtained about the affected site(s). TIBs may be used to assist NIOSH staff in the completion of 

individual dose reconstructions. 

INTRODUCTION

In this document, the word “facility” is used as a general term for an area, building, or group of 

buildings that served a specific purpose at a site. It does not necessarily connote an “atomic weapons 

employer facility” or a “Department of Energy (DOE) facility” as defined in the Energy Employees 

Occupational Illness Compensation Program Act of 2000 [42 U.S.C. Sections 7385l(5) and (12)]. 

This document presents information that compares doses received by monitored CTWs to doses 

received by all other monitored workers. For the purposes of this document CTWs include, but are 

not limited to, laborers, mechanics, masons, carpenters, electricians, painters, pipefitters, insulators, 

boilermakers, sheet-metal workers, operating engineers, and iron workers. 

For the initial comparison on CTW and AMW doses, five DOE sites were selected to represent the 

DOE complex as a whole. These sites [Rocky Flats Plant, Savannah River Site (SRS), Y-12, K-25,

and Oak Ridge National Laboratory (ORNL)] represent the full spectrum of work (plutonium and 

uranium processing, reactor operations, weapons production, and research laboratory operations) 

associated with DOE facilities. Using external dosimetry data from these sites, an investigation and 

comparison was made to determine the relationship between the annual external doses received by 

CTWs and those received by AMWs at the 95th percentile. The annual external doses for CTWs are 

represented by more than 200,000 histories, while those for AMWs are represented by more than

1,000,000 histories. The investigation showed that for 1943 to 2005 the annual external doses to 

CTWs were typically bounded by the doses to AMWs. In a more detailed comparison, seven 

individual DOE sites were examined to determine if, at any time, the external dose to CTWs exceeded 

that to AMWs. There were instances where external doses to CTWs exceeded those to AMWs. This 

document presents the data that support the use of an adjustment factor to account for instances 

when CTWs received higher doses.

As part of the more detailed comparison mentioned above, six of the DOE sites were analyzed to 

determine if, at any time, the bioassay results for CTWs exceeded those of AMWs. It was concluded 

that no adjustment factors were needed for internal dose with the exception of the Hanford Site (see 

Section 8.4).

For new facility construction, most CTWs were unmonitored because no radioactive material would be 

installed until after the facility was commissioned. However, modifications or major maintenance of 

existing facilities could have involved exposure to radioactive materials and would require monitoring 

of some CTWs. 

Radiation safety regulations (e.g., AEC Manual-0523; and AEC Manual-0524) dating back to the 

1950s required all personnel working in a radiation area to wear a gamma-measuring film badge. At 

some sites, such as the Nevada Test Site, all personnel entering the site were required to wear a 

gamma-measuring film badge in conjunction with their security badge (NTSO-0525). As a 

consequence, all persons, including CTWs, working in a radiation area were routinely monitored for 

exposure to external radiation. In most instances, CTWs were not routinely included in the bioassay 

program of the site. However, CTWs were included in the bioassay program if they were suspected 

of having experienced a radioactive material intake.
Document No. ORAUT-OTIB-0052 Revision No. 01 Effective Date: 02/17/2011 Page 8 of 40

While safety regulations and facility-specific radiation protection practices required monitoring of 

radiation workers, it is recognized that under some circumstances some CTWs at a facility might not 

have been fully covered or monitored by the radiation protection programs at a site, regardless of 

whether they were employed by the Management and Operations (M&O) contractor or a construction 

subcontractor. The reasons for partial or altered monitoring of CTWs varied from facility to facility on

a site, but it was not uncommon to have minimal or alternative monitoring in place during the 

construction of new facilities that were separate from existing facilities. Further, there are instances in 

which a CTW’s dose records might be incomplete or unavailable. In such cases, the ability to perform 

a dose reconstruction for that CTW is limited by a lack of claimant-specific information and data, so 

the claimant is categorized as an unmonitored construction worker. During the development of this 

TIB, there was a consistent effort to identify CTWs who were monitored regardless of whether they 

were employed by the M&O contractor or a subcontractor. This document provides the basis and 

guidance for performing dose reconstructions for unmonitored CTWs.

Although there are limitations and conditions on the data sets used in this TIB, it is possible to 

separate and compare the external and internal doses received by CTWs and AMWs at a site. These 

comparisons are provided graphically in this TIB. From these comparisons, which are presented for 

sites that had differing missions, operations, facilities, and radioactive source terms, the relationship 

between doses received by CTWs and AMWs becomes evident. Specifically, the comparisons 

demonstrate that, with some important exceptions and conditions, the doses received by the 

monitored CTWs were typically bounded by the doses received by AMWs on the same site. To

account for instances in which unmonitored CTWs might have received higher doses than other 

monitored workers, the need for an adjustment factor was identified. The adjustment factor provides 

a dose reconstruction method that is favorable to claimants who have been categorized as 

unmonitored CTWs.

2.0

This document provides guidance for performing dose reconstructions for unmonitored CTWs. For 

the purpose of this document, unmonitored CTWs are defined as workers who worked on site at any 

time in the site’s history and might have been employed by the M&O contractor at any DOE site. 

These unmonitored CTWs include, but are not limited to, laborers, mechanics, masons, carpenters, 

electricians, painters, pipefitters, insulators, boilermakers, sheet-metal workers, operating engineers, 

and iron workers. It should be noted that, in some instances, the prime contractor is not necessarily 

the M&O contractor. For example, in the late 1980s at the Hanford Site, the M&O contractor in the 

100 Area was Westinghouse Hanford Company while the prime contractor was Kaiser Engineering 

Hanford.

PURPOSE

3.0

The guidance in this TIB is limited to dose reconstruction for unmonitored CTWs who:

SCOPE

1. Were employed by subcontractors or worked directly for the M&O contractor at any DOE site. 

These workers might have been brought on site by subcontractors to do construction work, but 

might not have been covered under the site’s radiological protection program. 

2. Worked at any time in the site’s history.

3. Do not have a complete exposure history such as that for external exposure; had no external 

monitoring at all or there were gaps of at least a year in their external monitoring or for internal 

exposure; had no internal monitoring at all; or the monitoring they had was inadequate to 

bound their potential exposure.
Document No. ORAUT-OTIB-0052 Revision No. 01 Effective Date: 02/17/2011 Page 9 of 40

3.1 LIMITATIONS AND EXCEPTIONS

Analysis and recommendations in this document are based on data that were readily available, and 

abundant enough to enable statistically significant comparisons. As a consequence, there could be 

unusual cases in which the recommendations of this document do not apply. Intakes of less common 

radionuclides, those other than uranium or plutonium, are not assessed. Refer to the site technical 

basis document (TBD) for information about less common radionuclides [1]. 

External dose to SRS pipefitters who were unmonitored and employed for a limited duration between 

1972 and 1974 or between 1990 and 1998 might be underestimated slightly. See ORAUT-OTIB-0020 

(ORAUT 2008) for additional guidance.

4.0

Many sources of data were used to develop this document. These included databases, such as the 

Comprehensive Epidemiologic Data Resource (CEDR), the Center for Epidemiologic Research 

(CER), the Radiation Exposure Monitoring System (REMS), and the SRS Health Protection Annual 

Radiation Exposure History (HPAREH), as well as annual reports based on AEC Form 190. 

SOURCES OF DATA

The quality, usability, and accessibility of the data varied, making a standardized comparison among 

sites difficult. For example, some data are available in a modern database as official records while 

others are available only as summaries in centralized compilations. Some data have rigorously 

characterized parametric descriptions, while others are described only by a mean value. At some 

sites, the AMW group includes the CTWs and at others it does not. Some site comparisons are made 

using data that have been corrected for external missed dose, while others are made without that 

correction. The analysis method was appropriately adapted to the differences in data, but in all cases 

the comparisons are consistent for each site. The outcome of a specific comparison might have been 

affected by these differences, but only negligibly in the context of the threshold for adjustment 

described in Section 4.2 [2].

During the review and query of the databases, there was a consistent effort to identify all CTWs 

regardless of whether they were employed by the M&O contractor or a subcontractor.

Because the source and degree of data specificity varied among the DOE sites, a brief description of 

the source and treatment of data associated with each site is provided.

4.1 GENERAL DESCRIPTION OF EXTERNAL DOSE DATA

External dose data represent the most widely available dosimetry data for radiation workers. Very 

large and well-defined external dosimetry databases exist for most DOE facilities. A number of the 

databases cover or contain data from the entire history of a site.

Data for penetrating dose are contained in various databases, some of which have more detail than 

others. Data for AMWs and CTWs are reported for SRS, Y-12, ORNL, K-25, Hanford Site, Idaho 

National Laboratory (INL), and Rocky Flats Plant. However, only the arithmetic mean of the annual 

external dose is available for INL and Hanford.

4.2 GENERAL DESCRIPTION OF THE ADJUSTMENT FACTOR

The need for an adjustment factor is considered when the annual external penetrating dose for CTWs 

exceeds that for AMWs. If the observed ratio of the annual external penetrating dose for CTWs to 

that of AMWs is less than 1.2, the observed ratios were not included in the site-specific tables. The 
Document No. ORAUT-OTIB-0052 Revision No. 01 Effective Date: 02/17/2011 Page 10 of 40

value of 1.2 is based on the characteristics of the dosimeter systems and their ability to measure dose 

(NRC 1989).

The adjustment factor addresses instances in which the annual external penetrating dose for CTWs 

exceeded that for AMWs. Because data from all sites in the DOE complex were not readily available 

for analysis and inclusion in this TIB, a prescribed DOE complex-wide adjustment factor is developed 

and described in Section 7.1.

4.3 GENERAL DESCRIPTION OF BIOASSAY DATA USED FOR INTERNAL DOSE

Bioassay data are available to cover the majority of large DOE sites. Bioassay programs are typically 

based on the need to monitor individuals or groups who had a recognized potential for intake of 

radioactive material. As a consequence, bioassay sampling programs or internal dose monitoring 

practices are more highly focused and applied more selectively to a smaller group of workers than 

external monitoring programs. In most instances, CTWs were not included in the routine bioassay 

program of the site. However, CTWs were regularly included in the bioassay program if they were 

suspected of having experienced a radioactive material intake. 

4.4 GENERAL DESCRIPTION OF NONPENETRATING DOSE DATA

Nonpenetrating dose data for CTWs and AMWs were available only for the SRS and Rocky Flats 

Plant. 

5.0

Five major DOE sites (SRS, Rocky Flats, Y-12, K-25, and ORNL) were selected to represent the DOE 

complex in an investigation to determine the relationship between the external annual doses received 

by CTWs and AMWs at the 95th percentile. These sites were selected because they represent a 

spectrum of DOE sites where major construction activities took place. More than 215,000 histories for 

CTWs and more than 1,000,000 histories for AMWs were examined. Figure 5-1 is a composite graph 

of the sites and shows the annual external penetrating dose for the period from 1943 through 2005. 

With the exception of 1955, Figure 5-1 shows that the external annual dose received by CTWs is well 

bounded by that received by AMWs. In 1955, the external annual dose received by CTWs exceeded 

that received by AMWs by approximately 20%. Based on this observation, seven sites were 

examined individually to determine if, at any time, the external or internal dose to CTWs exceeded the 

dose to AMWs. The seven sites included SRS, Rocky Flats, Y-12, K-25, ORNL, INL, and Hanford. 

Hanford and INL were not included with the initial five DOE sites because the dosimetry data available 

for them addressed only the mean of the external dose as opposed to the 95th percentile.

COMPARISON OF CTW AND AMW DOSES

As indicated in Figure 5-1, doses to CTWs occasionally exceeded doses to AMWs in the 1980s and 

later. A review of the data used in the figure indicated that these exceedances are an artifact caused 

by a large number of AMWs with no measured dose. The large number of AMWs with no measured 

dose led to a smaller value for the 95th-percentile annual dose, making the 95th-percentile annual 

dose for CTWs comparatively larger.
Document No. ORAUT-OTIB-0052 Revision No. 01 Effective Date: 02/17/2011 Page 11 of 40

Figure 5-1. 95th-percentile annual penetrating dose for CTWs and AMWs for the DOE complex. 

5.1 SRS PENETRATING DOSE COMPARISON

Information for the period from 1953 through 1999 concerning penetrating doses for SRS CTWs is 

contained in the onsite personnel dosimetry database, HPAREH. The dosimetry data for the SRS 

CTWs in the HPAREH database are identified as Payroll 4 (ROLL 4). This information is subdivided 

to identify specific construction trades. However, some trades were not represented or represented

only a few individuals. As a consequence, conclusions for the period from 1953 through 1999 are 

based only from ROLL 4 data as a whole. 

Dosimetry data include annual deep doses (i.e., external photon radiation) and annual shallow doses 

(i.e., penetrating photons plus nonpenetrating radiation). Summary statistics in this document do not 

extend after 1999 because at the time information supporting this document was collected, sufficient 

data beyond that year were not available. Figure 5-2 shows the 95th-percentile penetrating dose for 

SRS.

The usefulness of data from other sources besides HPAREH was evaluated. The Fayerweather

database contains some data before 1960 that are not in HPAREH. S. Cohen & Associates 

compared reconstructed doses using the HPAREH and Fayerweather data and concluded that the 

average and 95th-percentile doses are higher when the HPAREH data are used (SC&A 2007). This 

provides some assurance that the workers in the Fayerweather database are adequately represented 

by those in the HPAREH database and the analysis is favorable to the CTW claimant [3].

95th-Percentile Annual Penetrating Dose for CTWs and AMWs for the DOE Complex 

(CTW = 216,742 Histories; AMW = 1,013,007 Histories)

0

500

1,000

1,500

2,000

2,500

1943 1955 1970 1985 2000

Year

Dose (mrem)

CTW mrem

AMW mrem
Document No. ORAUT-OTIB-0052 Revision No. 01 Effective Date: 02/17/2011 Page 12 of 40

Figure 5-2. 95th-percentile penetrating dose for SRS.

Table 5-1 lists the observed ratios that are greater than 1.2 for CTWs and AMWs at SRS.

Table 5-1. Observed ratios for SRS.

Year

CTWs AMWs

Observed 

ratios

(CTWs/AMWs)

Number 

monitored

Number with 

measurable 

dose

95thpercentile 

dose (mrem)

Number 

monitored

Number with 

measurable 

dose

95thpercentile 

dose (mrem)

1962 259 236 1,696 3,371 3,101 1,337 1.3

1989 2,408 1,818 218 15,517 8,749 170 1.3

1990 2,440 1,567 190 18,494 8,503 150 1.3

1991 2,202 1,104 120 18,630 6,468 85 1.4

1992 1,902 792 95 17,780 5,016 70 1.4

1997 949 317 83 11,344 2,410 55 1.5

1998 870 280 71 10,750 2,210 54 1.3

1999 785 240 62 10,365 2,159 49 1.3

5.2 SRS INTERNAL DOSE COMPARISON

For the SRS, no coworker study has been published. During the development of this TIB, bioassay 

data were not available electronically before about 1990 and were stored both on and off the site in 

paper files and on microfiche. A random sample of records stored on the site was obtained for 

workers with a nonzero external dose recorded in the HPAREH database. 

Equal number of records for CTWs and other workers were requested for individuals employed from 

1955 through 2000. CTWs were identified as ROLL 4 in the HPAREH database.

This sampling produced a data set containing approximately 1,830 plutonium-in-urine measurements, 

one-third of which represented CTWs. According to ORAUT (2005a), before 1981 (1988 for special 

95th-Percentile Annual Penetrating Dose for SRS

0

500

1000

1500

2000

2500

1953 1957 1961 1965 1969 1973 1977 1981 1985 1989 1993 1997

Year

Dose (mrem)

CTW

AMW
Document No. ORAUT-OTIB-0052 Revision No. 01 Effective Date: 02/17/2011 Page 13 of 40

samples), the total activity from alpha-emitting isotopes was used to report the amount of plutonium in 

urine, whereas 238Pu and 239+240Pu results were reported separately from 1981 to the present. 

Because this comparison is of the relative activities in the samples, no adjustments were made. All 

results were normalized to 1,400-mL sample size. Results for employees with multiple bioassay 

samples in the same year following a significant intake were removed prior to plotting. This was done 

so as not to bias the results for more typical workers. However, results less than 10 dpm/1,400 mL 

were retained even if there were other samples collected in the same year. Results for three nonCTWs and one CTW were removed using this method. 

For non-CTWs, 93% of the results were below the reporting level, while for CTWs, 97% of the results 

were below the reporting level. Only results greater than the reporting level are plotted in Figure 5-3. 

Due to the limited amount of data greater than the reporting level in any given period, no attempt was 

made to calculate 50th-percentile values. Figure 5-3 includes the typical reporting level estimated by 

a visual inspection of the various periods for comparison. This plot shows that non-CTWs were more 

likely to have results above the reporting level and more likely to have higher results than CTWs.

Figure 5-3. Results of bioassay samples above the reporting level for randomly selected CTWs 

and non-CTWs at SRS. 

5.3 SRS NONPENETRATING DOSE COMPARISON

As mentioned in Section 5.1, information for the period from 1953 through 1999 on nonpenetrating 

doses for SRS AMWs and CTWs is contained in the onsite personnel dosimetry database, HPAREH. 

The dosimetry data for the SRS CTWs are identified as Payroll 4 (ROLL 4) in the database.

The results for the 95th-percentile annual nonpenetrating doses appear in Figure 5-4. As is evident, 

the annual nonpenetrating dose received by the monitored CTWs is adequately bounded by the dose 

received by AMWs at the SRS. 
Document No. ORAUT-OTIB-0052 Revision No. 01 Effective Date: 02/17/2011 Page 14 of 40

Figure 5-4. 95th-percentile nonpenetrating dose for SRS.

5.4 ROCKY FLATS PLANT PENETRATING DOSE COMPARISON

Construction worker data for the Rocky Flats Plant was obtained from the HIS-20 (TM CANBERRA)

database. This database was the Plant’s last dosimetry data tracking system and contains dosimeter 

results from the entire Plant history. The CTW data set consisted of workers with the company names 

”Kaiser-Hill Company, L.L.C.” (if the department field contained “construct”), “Kaiser-Hill 

RFETS\10389” (if the department field contained “construct”), “Swinerton & Walberg Company,” and 

“J. A. Jones Construction\3893.” The latter two companies were the construction contractors for most 

of the Plant’s history.

Figure 5-5 shows the annual penetrating doses for monitored CTWs and AMWs for the period 1955 

through 2005. 

95th-Percentile Annual Nonpenetrating Dose for SRS

0

1000

2000

3000

4000

5000

6000

7000

1953 1957 1961 1965 1969 1973 1977 1981 1985 1989 1993 1997

Year

Dose (mrem)

CTW

AMW
Document No. ORAUT-OTIB-0052 Revision No. 01 Effective Date: 02/17/2011 Page 15 of 40

Figure 5-5. 95th-percentile penetrating dose for Rocky Flats.

Table 5-2 lists the observed ratios that are greater than 1.2 for CTWs and AMWs at Rocky Flats. 

Table 5-2. Observed ratios for Rocky Flats. 

Year

CTWs AMWs Observed 

ratios

(CTWs/ 

AMWs)

Number 

monitored

Number with 

measurable 

dose

95thpercentile 

dose (mrem)

Number 

monitored

Number with 

measurable 

dose

95thpercentile 

dose (mrem)

1991 386 340 755 5,641 4,951 337 2.2

1994 147 96 242 4,839 3,198 179 1.4

1995 138 88 455 4,130 2,502 200 2.3

1996 109 95 393 3,454 2,761 274 1.4

1998 265 218 592 3,470 2,036 275 2.2

1999 197 151 359 3,655 2,138 192 1.9

2000 175 110 278 3,576 1,256 164 1.7

2001 185 108 202 3,443 1,518 160 1.3

5.5 ROCKY FLATS PLANT INTERNAL DOSE COMPARISON

Construction worker data for Rocky Flats internal dose comparison was obtained from the HIS-20 

database. Two sets of data containing urine results for the entire history of the Plant were drawn from 

the database. The first data set consisted of workers with the company names “EG&G Rocky Flats

Plant” and “Kaiser-Hill Company, L.L.C.” (if the department field did not contain “construct”), “KaiserHill RFETS\10389” (if the department field did not contain “construct”), “Safe Sites of Colorado, 

L.L.C.,” and “Rocky Mt Remediation Srv\10528.” This set was selected to represent AMWs. 

The second data set consisted of workers with the company names ”Kaiser-Hill Company, L.L.C.” (if

the department field contained “construct”), “Kaiser-Hill RFETS\10389” (if the department field 

contained “construct”), “Swinerton & Walberg Company,” and “J. A. Jones Construction\3893.” The 

95th-Percentile Annual Penetrating Dose for Rocky Flats

0

500

1000

1500

2000

2500

3000

3500

4000

4500

5000

1954 1959 1964 1969 1974 1979 1984 1989 1994 1999 2004

Year

Dose (mrem)

CTW

AMW
Document No. ORAUT-OTIB-0052 Revision No. 01 Effective Date: 02/17/2011 Page 16 of 40

latter two companies were the construction contractors for most of the site’s history. This second data 

set was used to represent CTWs. A number of smaller companies could have been added, but the 

number of urine results would not have increased significantly. 

The data set included only results that were identified in the database as “P,” “Pu239,” or “Pu-239.” 

The results included the activity of all plutonium alphas in the early years, and only 239Pu and 240Pu 

activity after analysis by alpha spectroscopy was initiated [see ORAUT (2007) for details]. For the 

period from 1953 through 2005, 129,225 results were collected for AMWs and 5,571 results were 

collected for CTWs.

The Rocky Flats data were analyzed by applying the basic techniques discussed in ORAUT (2005b)

for coworker studies. The data were assumed to be lognormally distributed. Results for highly 

exposed workers who were followed-up with multiple samples in 1 year were removed from the 

population so as not to bias the results for more typical workers. However, not all high results were 

removed. This resulted in multiple individuals having their results removed from the AMW data set, 

but only one individual’s results were removed from the CTW data set. The data were analyzed 

annually for AMWs, while the data for CTWs were grouped in intervals of every 5 years to include 

enough data for statistical analysis. Each group was examined, and duplicate and invalid results were 

eliminated. Negative and zero results were replaced by a uniform (linear) distribution ending at the 

minimum detectable activity value in ORAUT (2007). The results were assumed to represent 24-hour

samples or were normalized to 24-hour samples by volume in years where volumes were recorded in 

the database. The results were sorted and ranked using the midpoint of the rank. A linear regression 

analysis of the rank versus the natural log of the result was performed and plotted. The R2 value of 

the regression and the plot were inspected to ensure that an adequate fit to the data had been 

obtained. From the regression, the values for the 50th- and the 84th-percentiles of the distributions 

were calculated and are shown in Figures 5-6 and 5-7, respectively. As shown in these figures, the 

results for plutonium in the urine of the CTWs are comparable to results for AMWs who were 

monitored routinely at Rocky Flats. 
Document No. ORAUT-OTIB-0052 Revision No. 01 Effective Date: 02/17/2011 Page 17 of 40

Figure 5-6. 50th-percentile plutonium in urine for Rocky Flats.

50th-Percentile Plutonium in Urine Results for Rocky Flats

0.00

0.05

0.10

0.15

0.20

0.25

0.30

0.35

1953 1957 1961 1965 1969 1973 1977 1981 1985 1989 1993 1997 2001 2005

Year

Pu-239 dpm/d

CTW

AMW
Document No. ORAUT-OTIB-0052 Revision No. 01 Effective Date: 02/17/2011 Page 18 of 40

Figure 5-7. 84th-percentile plutonium in urine for Rocky Flats.

5.6 ROCKY FLATS PLANT NONPENETRATING DOSE COMPARISON

CTW and AMW data for Rocky Flats were obtained from the HIS-20 database using the criteria 

discussed in Section 5.4.

The results for the 95th-percentile annual nonpenetrating doses appear in Figure 5-8 and show that at 

the 95th percentile, the annual nonpenetrating dose received by the monitored CTWs at the Rocky 

Flats Plant is adequately bounded by the dose received by AMWs at the Rocky Flats Plant.

84th-Percentile Plutonium in Urine Results for Rocky Flats 

0.00

0.20

0.50

0.60

0.80

1.00

1.20

1.50

1953 1957 1961 1965 1969 1973 1977 1981 1985 1989 1993 1997 2001 2005

Year

Pu-239 dpm/d

CTW

AMW
Document No. ORAUT-OTIB-0052 Revision No. 01 Effective Date: 02/17/2011 Page 19 of 40

Figure 5-8. 95th-percentile nonpenetrating dose for Rocky Flats.

5.7 Y-12 PENETRATING DOSE COMPARISON

External dose data for the Oak Ridge Y-12 are from the Oak Ridge Institute for Science and 

Education (ORISE) CER database. The records in this database include external radiation exposure 

measurement results pertinent to the health and safety monitoring of employees and contract 

employees of DOE and its predecessor organizations. Data on CTWs were obtained using a query 

designed to extract job titles associated with construction work. Data on any worker with a job title 

that included any of the following words or portions of words were included in the CTW data set: craft, 

carp, equip, heavy, plumb, pipef, millw, ship, skill, laborer, black, linem, boil, brick, tile, metal w, metal, 

crane, paint, mason, sheet, maint, truck, weld, rigger, or iron.

Figure 5-9 shows the data for 95th-percentile penetrating dose for monitored CTWs and AMWs for the 

period from 1950 through 1988. As shown in Figure 5-9, the 95th-percentile annual penetrating dose 

received by the monitored CTWs at Y-12 is adequately bounded by the doses received by AMWs at 

Y-12. 

95th-Percentile Nonpenetrating Dose for Rocky Flats

0

1000

2000

3000

4000

5000

6000

1955 1959 1965 1969 1975 1979 1985 1989 1995 1999 2005

Year

Dose (mrem)

CTW

AMW
Document No. ORAUT-OTIB-0052 Revision No. 01 Effective Date: 02/17/2011 Page 20 of 40

Figure 5-9. 95th-percentile penetrating dose for Y-12.

5.8 Y-12 INTERNAL DOSE COMPARISON

Bioassay results for uranium in urine samples for personnel who worked at Y-12 are from the ORISE 

CER database. Data on CTWs were obtained using a query designed to extract job titles associated 

with construction work. (See Section 5.7 for details on the data query.) 

Data generated by the query were reviewed to determine if a singular sample result or results 

associated with unusual incidents was unduly influencing the overall data comparison. Such data are 

characterized as outliers and these results were removed from the data set to improve the value of 

the data comparison. 

The 50th and 84th percentiles of these bioassay results are shown by year in Figures 5-10 and 5-11, 

respectively. In general, there is good agreement between the sample results for CTWs and AMWs.

Y-12 95th-Percentile External Dose

0

200

400

600

800

1000

1200

1950 1955 1960 1965 1970 1975 1980 1985 1990

Dose (mrem)

CTW

AMW
Document No. ORAUT-OTIB-0052 Revision No. 01 Effective Date: 02/17/2011 Page 21 of 40

Figure 5-10. 50th-percentile uranium in urine for Y-12.

Figure 5-11. 84th-percentile uranium in urine for Y-12.

0

2

4

6

8

10

12

14

16

18

1945 1950 1955 1960 1965 1970 1975 1980 1985 1990

AMW

dpm/d

CTW

Y-12 50th-Percentile Uranium in Urine

Y-12 84th-Percentile Uranium in Urine

0

10

20

30

40

50

60

1945 1950 1955 1960 1965 1970 1975 1980 1985 1990

dpm/d

AMW

CTW
Document No. ORAUT-OTIB-0052 Revision No. 01 Effective Date: 02/17/2011 Page 22 of 40

5.9 K-25 PENETRATING DOSE COMPARISON

External dose data for K-25 are taken from the ORISE CER database. The records in this database 

include external radiation exposure measurement results pertinent to the health and safety monitoring 

of employees and contract employees of DOE and its predecessor organizations. Data on CTWs 

were obtained using a query designed to extract job titles associated with construction work. (See 

Section 5.7 for details on the data query.) 

Figure 5-12 shows the data for the 95th-percentile penetrating dose for both monitored CTWs and 

AMWs for the period beginning in 1943 and ending in 1988. Figure 5-12 shows that the annual 

penetrating dose received by the monitored CTWs at K-25 is adequately bounded by the doses 

received by AMWs at K-25. 

Figure 5-12. 95th-percentile penetrating dose for K-25.

5.10 K-25 INTERNAL DOSE COMPARISON

Bioassay results for uranium in urine samples for personnel who worked at K-25 are from the ORISE 

CER database. Data on CTWs were obtained using a query designed to extract job titles associated 

with construction work. (See Section 5.7 for details on the data query.) 

The 50th and 84th percentile of these bioassay results are shown in Figures 5-13 and 5-14, 

respectively. In general, there is good agreement between the sample results for CTWs and AMWs. 

K-25 95th-Percentile External Dose

0

100

200

300

400

500

600

700

800

1945 1950 1955 1960 1965 1970 1975 1980 1985 1990

Dose (mrem)

CTW

AMW
Document No. ORAUT-OTIB-0052 Revision No. 01 Effective Date: 02/17/2011 Page 23 of 40

Figure 5-13. 50th-percentile uranium in urine for K-25.

Figure 5-14. 84th-percentile uranium in urine for K-25.

K-25 50th-Percentile Uranium in Urine Results

0

0.2

0.4

0.6

0.8

1

1.2

1.4

1945 1950 1955 1960 1965 1970 1975 1980 1985 1990

alpha dpm/100 mL

CTW

AMW

K-25 84th-Percentile Uranium in Urine Results

0

0.5

1

1.5

2

2.5

3

3.5

1945 1950 1955 1960 1965 1970 1975 1980 1985 1990

alpha dpm/100 mL

CTW

AMW
Document No. ORAUT-OTIB-0052 Revision No. 01 Effective Date: 02/17/2011 Page 24 of 40

5.11 ORNL PENETRATING DOSE COMPARISON

External dose data for ORNL are from the ORISE CER database. The records in this database 

include external radiation exposure measurement results pertinent to the health and safety monitoring 

of employees and contract employees of DOE and its predecessor organizations. Data on CTWs 

were obtained using a query designed to extract job titles associated with construction work. (See 

Section 5.7 for details on the data query.) 

Figure 5-15 shows the 95th-percentile annual penetrating dose for monitored CTWs and AMWs at the 

ORNL for the period from 1943 through 1988.

Figure 5-15. 95th-percentile penetrating dose for ORNL.

ORNL 95th-Percentile External Dose

0

500

1000

1500

2000

2500

3000

1940 1950 1960 1970 1980 1990

Dose (mrem)

CTW

AMW
Document No. ORAUT-OTIB-0052 Revision No. 01 Effective Date: 02/17/2011 Page 25 of 40

Table 5-3 lists the observed ratios that are greater than 1.2 for CTWs and AMWs at ORNL. 

Table 5-3. Observed ratios for ORNL. 

Year

CTWs AMWs

Observed 

ratios

(CTWs/AMWs)

Number 

monitored

Number with 

measurable 

dose

95thpercentile 

dose

(mrem)

Number 

monitored

Number with 

measurable 

dose

95thpercentile 

dose

(mrem)

1955 604 470 2,231 3,931 2,193 1,650 1.4

1957 623 608 2,515 4,277 3,734 1,750 1.4

1959 704 696 2,058 4,698 4,350 1,636 1.3

1960 682 618 1,480 4,793 3,427 1,087 1.4

1961 695 627 1,096 4,779 3,785 810 1.4

1962 722 696 1,200 4,953 4,591 940 1.3

1963 750 681 1,015 5,174 4,243 803 1.3

1965 817 551 864 5,646 2,930 680 1.3

1966 822 582 1,040 5,972 2,765 680 1.5

1967 878 585 1,163 6,252 2,657 780 1.5

1968 852 542 814 5,981 2,303 610 1.3

1969 808 403 670 5,809 1,754 516 1.3

1971 725 318 558 5,154 1,428 390 1.4

1972 691 289 645 5,097 1,203 422 1.5

1973 661 315 620 4,984 1,336 400 1.6

1974 739 363 421 5,407 1,611 250 1.7

1975 767 283 457 5,788 1,129 290 1.6

1976 784 268 378 6,123 1,169 210 1.8

1977 804 228 250 6,434 1,042 160 1.6

1978 798 206 333 6,660 899 160 2.1

1979 776 209 440 6,357 915 182 2.4

1980 754 130 214 6,480 635 70 3.1

1981 723 170 409 6,313 606 150 2.7

1982 667 119 247 5,782 480 130 1.9

1983 608 146 436 5,562 489 170 2.6

1984 602 144 339 5,610 522 150 2.3

1985 585 139 288 5,641 502 130 2.2

1986 514 94 193 4,998 430 100 1.9

1987 482 92 138 4,894 382 70 2.0

1988 484 91 134 5,102 372 50 2.7

5.12 ORNL INTERNAL DOSE COMPARISON

Bioassay results for urine samples for personnel who worked at ORNL are from the ORISE CER

database. Data on CTWs were obtained using a query designed to extract job titles associated with 

construction work. (See Section 5.7 for details on the data query.) 

From 1951 through 1964, plutonium in urine was measured as gross alpha. From 1965 to 1987, the 

analysis method became specific for plutonium. The 50th and 84th percentiles of these bioassay 

results are shown by year in Figures 5-16 and 5-17, respectively. 

Uranium in urine was also measured at ORNL. Figures 5-18 and 5-19 show the results of the median 

and 84th percentile for this analysis, respectively. 

In general, there is good agreement between the CTW and AMW data for both plutonium and uranium 

at the 50th and 84th percentile.
Document No. ORAUT-OTIB-0052 Revision No. 01 Effective Date: 02/17/2011 Page 26 of 40

Figure 5-16. 50th-percentile plutonium in urine for ORNL.

Figure 5-17. 84th-percentile plutonium in urine for ORNL.

ORNL 50th-Percentile Plutonium in Urine Results

0

0.0

0.

0.1

0.

0.2

1945 1950 1955 1960 1965 1970 1975 1980 1985 1990

dpm/d

CTW

AMW

ORNL 84th-Percentile Plutonium in Urine Results

0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

1945 1950 1955 1960 1965 1970 1975 1980 1985 1990

dpm/d

CTW

AMW
Document No. ORAUT-OTIB-0052 Revision No. 01 Effective Date: 02/17/2011 Page 27 of 40

 Figure 5-18. 50th-percentile uranium in urine for ORNL.

 Figure 5-19. 84th-percentile uranium in urine for ORNL.
Document No. ORAUT-OTIB-0052 Revision No. 01 Effective Date: 02/17/2011 Page 28 of 40

5.13 INL PENETRATING DOSE COMPARISON

Penetrating doses for INL are presented in Figure 5-20 for the period beginning in 1974 and ending in 

2005. Radiation exposure data prior to 1974 was not available. However, in Occupational Radiation 

Exposure History of Idaho Field Office Operations at the INEL, Horan and Braun (1993) discuss

construction worker exposures during the early period: “[Construction personnel] exposures were 

negligible during the first decade and were almost all below 0.5 rem/yr thereafter.” 

Data in NIOSH (2005) were considered for comparison but rejected because they include data on 

civilian employees of the Naval Reactor Facilities who are not covered by EEIOCPA. Also 

confounding those data is the fact that service workers are grouped with CTW, a practice that is 

inconsistent with the definition of CTW in this document [4].

Figure 5-20. Mean value for penetrating dose for INL.

Average Annual Penetrating Dose for INL

0

100

200

300

400

500

600

700

1974 1976 1978 1980 1982 1984 1986 1988 1990 1992 1994 1996 1998 2000 2002 2004 2006

Dose (mrem)

CTW

AMW
Document No. ORAUT-OTIB-0052 Revision No. 01 Effective Date: 02/17/2011 Page 29 of 40

Table 5-4 lists the observed ratios that are greater than 1.2 for CTWs and AMWs at INL.

Table 5-4. Observed ratios for INL. 

Year

CTWs AMWs

Observed 

ratios

(CTWs/AMWs)

Number 

monitored

Number with 

measurable 

dose

Average 

dose (mrem)

Number 

monitored

Number with 

measurable 

dose

Average 

dose (mrem)

1979 953 396 461 5,097 2,407 360 1.3

1986 1,321 536 479 5,956 1,994 296 1.6

1988 463 311 186 4,813 1,751 135 1.4

1989 416 263 317 5,385 1,829 172 1.8

1990 430 223 260 6,033 1,960 177 1.5

1992 427 157 134 5,889 1,007 87 1.5

1994 418 211 180 6,006 1,659 143 1.3

1998 384 104 146 5,075 743 87 1.7

1999 565 95 101 8,885 729 66 1.5

2003 422 155 70 4,682 1,141 56 1.3

2004 428 186 109 3,853 1,471 74 1.5

5.14 INL INTERNAL AND NONPENETRATING DOSE COMPARISON

Data for internal exposures for workers at the INL were not available in a validated electronic format 

[5]. However, the Horan and Braun (1993) report briefly discusses nonpenetrating and internal 

exposures, and indicates that they were traditionally negligible: 

Non-penetrating radiation exposure to the skin from soft X-rays or Beta particles were 

also not included along with irradiation by internally deposited radionuclides since 

historically they have been extremely rare events and as a result a very minor 

contributor to the effective dose.

No comparison of CTW and AMW internal dose or nonpenetrating dose is presented. Nevertheless,

general guidance for internal dose reconstruction developed in this document applies to unmonitored 

CTWs at INL [6]. 

6.0

Hanford was the first facility to generate and separate special nuclear material for weapons 

production. As such, Hanford can be viewed as a type of research and development facility where 

chemical separation processes were one-of-a-kind experimental prototypes. As the 

research/information base grew and new chemical processes were developed, contaminated facilities 

were retrofitted or replaced to accommodate the new processes. It is postulated that this practice was 

responsible for elevated doses to CTWs. As a consequence, adjustment factors are developed to 

augment the dose to the CTWs during specific periods.

HANFORD SITE

6.1 HANFORD SITE PENETRATING DOSE COMPARISON

The data were extracted from various sources including a scientific paper (Keene 1960), a series of 

annual reports based on AEC Form 190 and a series of letter reports (Foster et al. 1959-1973), the 

annual summary reports of radiation exposures (DOE 1978, 1980a,b, 1982, 1983, 1984a,b, 1985, 

1986, 1987, 1989, 1990; ERDA 1975, 1976; Smith et al. 1993), the REMS database (DOE 2006), and 

a Hanford coworker study of external dose (ORAUT 2010a).
Document No. ORAUT-OTIB-0052 Revision No. 01 Effective Date: 02/17/2011 Page 30 of 40

The data from Keene (1960) for the period from 1944 through1959 consist of the 14 job categories 

that have the highest accumulated dose for that period. Five of the job categories are assumed to 

represent CTWs. The number of workers, the average service in years, and the average dose are

provided for each job category. From these data, average doses per year are calculated for CTWs 

and AMWs. 

From 1960 through 1972, the data come from letters, required by AEC Order, summarizing the site 

annual dose data (Foster et. al. 1959–1973) [7]. The reports generally present the annual dose in 

ranges (0–1 rem, 1–2 rem, etc.). In those instances, the value of the midpoint of each range was 

used to calculate the average dose. 

No annual report was located for 1973. From 1974 through 1990 the data were extracted from the

Annual Report, Radiation Exposures for DOE and DOE Contractor Employees (DOE 1978, 1980a,b, 

1982, 1983, 1984a,b, 1985, 1986, 1987, 1989, 1990; ERDA 1975, 1976; Smith et al. 1993) [8].

For the period from 1991 through 2005, the doses for CTWs and AMWs are determined using the 

REMS database (DOE 2006). The annual collective penetrating dose is determined by subtracting 

the collective committed effective dose equivalent (if any) from the collective total effective dose 

equivalent (person-mrem). The average penetrating dose is determined by dividing the annual dose 

by the number of workers with measured dose. For CTWs, the annual dose is determined by 

summing the annual doses for the REMS Construction and Laborer labor categories. The workers in 

the Laborers category are segregated by the reporting organizations. The annual doses reported by 

the organizations that are not the M&O contractor are summed and added to the annual dose for the 

Construction category. Doses in the range less than 100 mrem are not included; this eliminates most 

visitors and administrative personnel from the REMS data. The average annual dose for CTWs is 

determined by dividing the annual dose for the Laborers and Construction categories by the number 

of workers in those categories with measurable dose. For AMWs, the average annual dose is 

determined by summing the annual doses in the REMS All category (management, scientists, service, 

etc.) and dividing that sum by the sum of workers who had measured dose in the All category.

Use of data from the REX database was considered and rejected. The site expert cautioned that 

before 1965 the database contains no information that would differentiate CTWs from General Electric 

employees [9].

Penetrating doses for monitored CTWs and AMWs are shown in Figure 6-1. Table 6-1 lists the 

observed ratios that are greater than 1.2 for CTWs and AMWs at Hanford. As indicated in the figure

and table, the doses for the CTWs and AMWs are comparable with two exceptions: the periods from 

1968 through 1981 and from 1985 through 1988. These periods generally coincide with the increased 

work activity associated with the shutdown of the production reactors from 1968 through 1981 and the 

restart of the Purex Plant from 1985 through 1988. Due to the nature and period for this work, it is 

unlikely that unmonitored CTWs were involved. Therefore, these data points were not considered as 

representative and meaningful for the purposes of this TIB. 
Document No. ORAUT-OTIB-0052 Revision No. 01 Effective Date: 02/17/2011 Page 31 of 40

Figure 6-1. Average annual penetrating dose for Hanford.

Table 6-1. Observed ratios and average penetrating dose for CTWs and AMWs at Hanford.

Year

CTWs AMWs

Observed ratios

(CTWs/AMWs)

Number 

monitored

Number with 

measurable 

dose

Average dose 

(mrem)

Number with 

measurable 

dose

Average dose 

(mrem)

1970 1,365 1,158 1,020 10,053 702 1.5

1975 408 402 1,036 3,578 745 1.4

1978 1,917 1,864 467 6,882 372 1.3

1979 1,915 1,770 422 7,517 332 1.3

1980 1,585 1,437 537 6,917 320 1.7

1981 1,542 1,386 479 7,182 286 1.7

1985 1,642 808 660 5,954 427 1.5

1987 1,804 1,225 793 6,697 393 2.0

1990 934 428 181 3,753 119 1.5

1993 1,351 556 196 3,147 133 1.5

1994 1,696 567 222 3,166 150 1.5

1997 1,022 366 393 2,058 284 1.4

Sources:1960-1973 from various Hanford letter reports (Foster at al. 1959-1973)

1975-1990 from DOE annual dose reports (DOE 1978, 1980a,b, 1982, 1983, 1984a,b, 1985, 1986, 1987, 1989, 

1990; ERDA 1975, 1976; Smith et al. 1993)

1991-2005 from the DOE REMS database (DOE 2006)

6.2 HANFORD SITE INTERNAL DOSE COMPARISON

An internal dosimetry coworker study that includes both CTWs and AMWs has been published for the 

Hanford Site (ORAUT 2010b). The database used to develop the study had limited descriptive 

Hanford Average Penetrating 

Dose

0

20

0

40

0

60

0

80

0

100

0

120

0

1955-

1959

1960 1965 1970 1975 1980 1985 1990 1995 2000 2005

Dose (mrem)

CTW

AMW
Document No. ORAUT-OTIB-0052 Revision No. 01 Effective Date: 02/17/2011 Page 32 of 40

information for workers such that data for CTWs cannot be identified before 1965. For the period from 

1965 through 1978, plutonium data for CTWs is identified by a company-field in the database. These 

data were processed in accordance with ORAUT (2010b) to develop data sets for CTWs. For the 

period from 1965 through 1975, the data sets were analyzed annually rather than quarterly due to 

their small size. For the period from 1975 through 1978, the data sets were grouped and analyzed 

together. [See ORAUT (2010b) for additional details.] 

For the period from 1978 through 1989, the plutonium data for CTWs are very limited and appear to 

consist mainly of special samples following incidents. If it was appropriate, duplicates and data for 

highly exposed individuals were removed because these data are not truly representative of CTWs as 

a group. However, no attempt was made to remove all special (follow-up) results. This approach for

reviewing and qualifying the data recognized that small intakes were essentially a part of routine 

operations. As in ORAUT (2010b), results with volumes less than 400 mL were not used in the 

statistics.

The results were assumed to be lognormally distributed and were analyzed using the basic 

techniques for coworker studies described in ORAUT-OTIB-0019, Analysis of Coworker Data for 

Internal Dose Assignment (ORAUT 2005b). The resultant 50th- and 84th-percentile values were 

multiplied by 0.835 to convert total plutonium alpha to 239Pu activity, assuming 10-year-aged fuelgrade plutonium. This conversion was necessary to make the results directly comparable to the 

values in ORAUT (2010b). 

The Hanford data forms included a field to enter the reason for the bioassay (“reason code”). 

Unfortunately, this field was not used consistently over the years in question; in addition, it was not 

reported in the Hanford coworker study. It appears that a high percentage of special bioassay 

samples might have biased the data for the years in which the data for CTWs are higher than the data 

for AMWs. The maximum difference between the CTW data and the AMW data was about a factor of 

2 but, as evident in Figures 6-2 and 6-3, the difference varied from year to year. It appears that 

applying a factor of 2 to the intake rates in the Hanford coworker study is favorable to construction 

worker claimants.

The results of the analysis and the data from ORAUT (2010b) appear in Figures 6-2 and 6-3.
Document No. ORAUT-OTIB-0052 Revision No. 01 Effective Date: 02/17/2011 Page 33 of 40

Figure 6-2. 50th-percentile for Pu-239 in urine for Hanford.

Figure 6-3. 84th-percentile for Pu-239 in urine for Hanford.

7.0

Comparisons between the doses received by CTWs and AMWs have shown that, with some 

exceptions and conditions, the doses received by the monitored CTWs were usually bounded by the 

doses received by AMWs on the same site.

CONCLUSIONS

This relationship between the doses received by CTWs and AMWs can be combined with the premise 

that the nature of the construction work (carpentry, masonry, pipefitting, etc.) performed by 

84th-Percentile Pu-239 Results for Hanford

0.00

0.02

0.04

0.06

0.08

0.10

0.12

1965 1966 1967 1968 1969 1970 1971 1972 1973 1974 1975 1976 1977 1978

Year

Pu-239 dpm/d

CTW

AMW

50th-Percentile Pu-239 Results for Hanford

0

0.005

0.01

0.015

0.02

0.025

1965 1966 1967 1968 1969 1970 1971 1972 1973 1974 1975 1976 1977 1978

Year

Pu-239 dpm/d

All Workers

Construction
Document No. ORAUT-OTIB-0052 Revision No. 01 Effective Date: 02/17/2011 Page 34 of 40

unmonitored CTWs was not significantly different (from a radiation protection perspective) from the 

construction work activities performed by monitored CTWs. Doses to monitored CTWs can, therefore,

serve as an acceptable surrogate for doses to unmonitored CTWs. 

An analysis of the specific DOE sites identified specific years that CTW doses exceeded AMW doses. 

To address these instances, an adjustment factor is needed.

More accurate dose reconstructions are possible at sites with abundant dosimetry data. At sites for 

which data are lacking, dose reconstruction methods tend to produce higher bounding doses and to 

be more favorable to the claimant. Application of the guidance in this document along with the sitespecific guidance available in TBDs results in dose reconstructions that are favorable to the 

unmonitored CTW claimant [10].

7.1 PRESCRIBED EXTERNAL ADJUSTMENT FACTOR FOR ALL DOE FACILITIES

Due to limitations on the availability and specificity of CTW and AMW data from other DOE sites, this 

TIB presents a limited analysis and comparison of CTW and AMW data. To reconcile this limited data 

analysis with the site-specific comparisons that indicate that external doses to CTWs occasionally 

exceeded doses to AMWs, a prescribed adjustment factor is needed for dose reconstructions for 

unmonitored CTWs. 

The prescribed external dose adjustment factor was based on consideration of the relative magnitude 

and trend in CTW and AMW doses shown in Figure 5-1, specifically: 

• CTW doses occasionally exceeded AMW doses during the late 1980s and 1990s. However, 

this reflects work in the DOE complex when radiation protection programs were well 

established and nearly all potentially exposed workers were monitored. Further, these 

occasional exceedances have been identified as artifacts caused by a large number of AMWs 

with no measurable dose.

• CTW doses were significantly lower than AMW doses for an extended period that started in 

1961. This indicates that the adjustment factor should be based on instances where CTW 

doses exceeded AMW doses before 1961. 

• The values for pre-1961 adjustment factors range from 1.3 to 1.4. 

• The maximum value of 1.4 was selected as the prescribed favorable to claimant external dose 

adjustment factor (i.e., dose multiplier) for all DOE facilities for all years. 

8.0

8.1 LIMITATIONS

LIMITATIONS AND APPLICATIONS

The application of the conclusions and adjustment factors derived in this document are limited to dose 

reconstructions for unmonitored construction workers at sites with applicable coworker data or an 

acceptable method for dose reconstruction for unmonitored workers. 

8.2 GUIDANCE ON THE DETERMINATION OF PENETRATING DOSE FOR 

UNMONITORED CONSTRUCTION TRADE WORKERS

Use the guidance in ORAUT-OTIB-0020 (ORAUT 2008) to assign a penetrating dose that is favorable 

to unmonitored CTWs. Apply an adjustment factor of 1.4 to the appropriate percentile of the 
Document No. ORAUT-OTIB-0052 Revision No. 01 Effective Date: 02/17/2011 Page 35 of 40

measured coworker data for the site, plus the assigned coworker missed dose, to determine the total 

assigned penetrating dose that is favorable to unmonitored CTWs.

For nonprime CTWs, the dose reconstruction method should use applicable coworker doses and the 

adjustment factor. For prime CTWs who have unmonitored periods when they should have been 

monitored, the dose reconstruction method should use coworker doses with the adjustment factor of 

1.4.

8.3 GUIDANCE ON THE DETERMINATION OF NONPENETRATING DOSE FOR 

UNMONITORED CONSTRUCTION TRADE WORKERS

Based on the comparison from SRS and Rocky Flats Plant, the annual nonpenetrating doses in the 

other coworker studies can be used to assign annual nonpenetrating doses to those CTWs whose 

dose history is unavailable or incomplete.

Due to a lack of data, it was not possible to provide a comparison of nonpenetrating doses from 

Hanford. Dose reconstructors should not apply any adjustment factors for nonpenetrating dose.

8.4 GUIDANCE ON THE DETERMINATION OF INTERNAL DOSE

For Hanford dose reconstructions covered by this TIB, the intake rates in the Hanford coworker 

document should be multiplied by a factor of 2. 

If coworker studies are available for other sites, assign a lognormal distribution with the dose equal to 

the 50th-percentile dose and assign the associated geometric standard deviation (GSD) to account for 

the possible variation in actual dose. The minimum value assigned to the GSD of a coworker data set 

is 3. 

8.5 GUIDANCE ON THE DETERMINATION OF OCCUPATIONAL MEDICAL DOSE

Dose reconstructors should review the claim file for X-ray records.

If there are X-ray records in the file, the dose reconstructor should use the TBD for the site where the 

worker performed the work to assign X-ray dose. For example, a worker who worked for Atkinson/

Jones at Hanford could have X-ray records in his/her file. The X-ray dose should be assigned from 

the Hanford TBD organ dose tables. The dose from any X-rays in the records that appear to have 

been taken off site at a non-covered facility should NOT be included in dose reconstruction.

For sites with an indication of “X-ray records do not exist” and there are in fact no-X-ray records in the 

file or for sites that are not currently including X-ray records, such as Y-12 and INL, the dose 

reconstructor should use the TBD for the site where the worker performed the work to assign the 

frequency and dose or X-ray procedures that are clearly not a result of work-related injury. 
Document No. ORAUT-OTIB-0052 Revision No. 01 Effective Date: 02/17/2011 Page 36 of 40

9.0

Where appropriate in the preceding text, bracketed callouts have been inserted to indicate 

information, conclusions, and recommendations to assist in the process of worker dose 

reconstruction. These callouts are listed in this section with information that identifies the source and 

justification for each item. Conventional references are provided in the next section that link data, 

quotations, and other information to documents available for review on the ORAU Team servers.

ATTRIBUTIONS AND ANNOTATIONS

[1] Chew, Melton H. M. H. Chew and Associates. Health Physicist, and Morris, Robert L. 

M.H. Chew and Associates. Health Physicist. September 2010.

This change was made as a result of the July 21, 2008 Advisory Board Work Group on 

Procedures meeting to close finding OTIB-0052-05.

[2] Chew, Melton H. M. H. Chew and Associates. Health Physicist, and Morris, Robert L. 

M.H. Chew and Associates. Health Physicist. September 2010.

This change was made as a result of the July 21, 2008 Advisory Board Work Group on 

Procedures meeting to close findings OTIB-0052-13 and OTIB-0052-14.

[3] Chew, Melton H. M. H. Chew and Associates. Health Physicist, and Morris, Robert L. 

M.H. Chew and Associates. Health Physicist. September 2010.

This change was made as a result of the July 21, 2008 Advisory Board Work Group on 

Procedures meeting to close finding OTIB-0052-08.

[4] Chew, Melton H. M. H. Chew and Associates. Health Physicist, and Morris, Robert L. 

M.H. Chew and Associates. Health Physicist. September 2010.

This change was made as a result of the July 21, 2008 Advisory Board Work Group on 

Procedures meeting to close finding OTIB-0052-10.

[5] Chew, Melton H. M. H. Chew and Associates. Health Physicist, and Morris, Robert L. 

M.H. Chew and Associates. Health Physicist. September 2010.

This change was made as a result of the July 21, 2008 Advisory Board Work Group on 

Procedures meeting to close finding OTIB-0052-11.

[6] Chew, Melton H. M. H. Chew and Associates. Health Physicist, and Morris, Robert L. 

M.H. Chew and Associates. Health Physicist. September 2010.

This change was made as a result of the July 21, 2008 Advisory Board Work Group on 

Procedures meeting to close finding OTIB-0052-11.

[7] Chew, Melton H. M. H. Chew and Associates. Health Physicist, and Morris, Robert L. 

M.H. Chew and Associates. Health Physicist. September 2010.

This change was made as a result of the July 21, 2008 Advisory Board Work Group on 

Procedures meeting to close finding OTIB-0052-12.

[8] Chew, Melton H. M. H. Chew and Associates. Health Physicist, and Morris, Robert L. 

M.H. Chew and Associates. Health Physicist. September 2010.

This change was made as a result of the July 21, 2008 Advisory Board Work Group on 

Procedures meeting to close finding OTIB-0052-12.

[9] Chew, Melton H. M. H. Chew and Associates. Health Physicist, and Morris, Robert L. 

M.H. Chew and Associates. Health Physicist. September 2010.

This change was made as a result of the July 21, 2008 Advisory Board Work Group on 

Procedures meeting to close finding OTIB-0052-12.
Document No. ORAUT-OTIB-0052 Revision No. 01 Effective Date: 02/17/2011 Page 37 of 40

[10] Chew, Melton H. M. H. Chew and Associates. Health Physicist, and Morris, Robert L. 

M.H. Chew and Associates. Health Physicist. September 2010.

This change was made as a result of the July 21, 2008 Advisory Board Work Group on 

Procedures meeting to close finding OTIB-0052-11.
Document No. ORAUT-OTIB-0052 Revision No. 01 Effective Date: 02/17/2011 Page 38 of 40

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