Draft 

ADVISORY BOARD ON 

RADIATION AND WORKER HEALTH 

National Institute for Occupational Safety and Health

REVIEW OF THE NIOSH SITE PROFILE FOR THE 

KANSAS CITY PLANT 

Contract No. 200-2009-28555 

SCA-TR-SP2012-0006 

Prepared by 

Ron Buchanan 

Joyce Lipsztein 

John Mauro 

Joseph Porrovecchio 

S. Cohen & Associates 

1608 Spring Hill Road, Suite 400 

Vienna, VA 22182 

September 2012 

Disclaimer 

This document is made available in accordance with the unanimous desire of the Advisory Board on 

Radiation and Worker Health (ABRWH) to maintain all possible openness in its deliberations. However, 

the ABRWH and its contractor, SC&A, caution the reader that at the time of its release, this report is predecisional and has not been reviewed by the Board for factual accuracy or applicability within the 

requirements of 42CFR82. This implies that once reviewed by the ABRWH, the Board’s position may 

differ from the report’s conclusions. Thus, the reader should be cautioned that this report is for 

information only and that premature interpretations regarding its conclusions are unwarranted.
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Document No. 

 SCA-TR-SP2012-0006 

Effective Date: 

 Draft – September 6, 2012 

S. COHEN & ASSOCIATES: 

Technical Support for the Advisory Board on 

Radiation & Worker Health Review of 

NIOSH Dose Reconstruction Program Revision No. 

0 – (Draft) 

REVIEW OF THE NIOSH SITE PROFILE FOR 

THE KANSAS CITY PLANT Page 2 of 29 

Task Manager: 

__________________________ Date:____________ 

Joseph Porrovecchio 

Supersedes: 

N/A 

Project Manager: 

__________________________ Date:____________ 

John Stiver, CHP 

Reviewer(s): 

 John Mauro 

 John Stiver 

 

Record of Revisions 

Revision 

Number 

Effective 

Date Description of Revision 

0 (Draft) 09/06/2012 Initial issue 
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NOTICE:

TABLE OF CONTENTS 

Abbreviations and Acronyms ..........................................................................................................4 

Executive Summary.........................................................................................................................6 

1.0 Introduction..........................................................................................................................8 

1.1 Scope of the Review ................................................................................................8 

1.1.1 Objective 1: Completeness of Data Sources...............................................8 

1.1.2 Objective 2: Technical Accuracy................................................................8 

1.1.3 Objective 3: Adequacy of Data...................................................................8 

1.1.4 Objective 4: Consistency among Site Profiles............................................9 

1.1.5 Objective 5: Regulatory Compliance and Quality Assurance ....................9 

1.2 Report Organization...............................................................................................10 

2.0 Background Information....................................................................................................11 

2.1 Summary of the History of Kansas City Plant (KCP) Operations.........................11 

2.2 Description of KCP’s Radiation Protection Program............................................11 

3.0 Occupational Medical Dose...............................................................................................12 

4.0 Occupational Environmental Dose ....................................................................................13 

5.0 Internal Dose......................................................................................................................14 

5.1 Introduction and Overview ....................................................................................14 

5.2 Uranium .................................................................................................................14 

5.2.1 Powder Activity Median Aerodynamic Diameter .....................................16 

5.2.2 Annual Sum of Bioassay Measurements...................................................17 

5.2.3 Bioassay Coworker Model.........................................................................18 

5.2.4 Chronic Uranium Intake ............................................................................18 

5.3 Other Radionuclides...............................................................................................19 

6.0 External Dose during Operations.......................................................................................20 

6.1 Background............................................................................................................20 

6.1.1 Accuracy/Completeness of Dose Records.................................................22 

6.1.2 Beta Dose...................................................................................................23 

6.1.3 Moderated Neutron Dose...........................................................................23 

6.1.4 Neutron Dosimetry Correction Factors......................................................24 

6.1.5 Neutron-to-Photon Ratios ..........................................................................25 

6.2 Coworker Data Issues............................................................................................26 

6.2.1 Dosimeter Response to Low-Energy Photons...........................................26 

6.2.2 KCP Site Profile Text Issues......................................................................27 

7.0 References..........................................................................................................................29 
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ABBREVIATIONS AND ACRONYMS 

Advisory Board 

or Board Advisory Board on Radiation and Worker Health 

AMAD activity median aerodynamic diameter 

AP anterior-posterior 

AWE Atomic Weapons Employer 

BNL Brookhaven National Laboratory 

cm2 square centimeter 

DCF dose conversion factor 

DOE U.S. Department of Energy 

DOELAP DOE Laboratory Accreditation Program 

dpm disintegrations per minute 

DU depleted uranium 

FRC Federal Records Center 

g/cm3 gram per cubic centimeter 

GSD geometric standard deviation 

Hp personal dose equivalent at tissue depth d (d = 10 mm or 0.07 mm) 

ICRP International Commission on Radiological Protection 

KCP Kansas City Plant 

μCi/m3 microcurie per cubic meter 

μg/L microgram per liter 

μm micron 

MDL minimum detectable level 

MeV million electron volt 

mg/cm2 milligram per square centimeter 

mrem millirem 

NARA National Archives and Records Administration 

NIOSH National Institute for Occupational Safety and Health 

NNSA National Nuclear Security Administration 

n/p neutron-to-photon ratio 

NOCTS NIOSH OCAS Claims Tracking System 

NTA Nuclear Track A (film) 
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pCi picocuries 

ORAUT Oak Ridge Associated Universities Team 

rem Roentgen equivalent man 

RGD radiation generating device 

SC&A S. Cohen and Associates (SC&A, Inc.) 

SRDB Site Research Database 

TBD Technical Basis Document 

TLD thermoluminescent dosimeter 

TMA Thermo Analytical, Inc. 

UO2 uranium oxide
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EXECUTIVE SUMMARY 

This report presents a review of ORAUT-TKBS-0031, Site Profile for the Kansas City Plant

(ORAUT 2006), which provides data and guidance for dose reconstruction of workers at the 

Kansas City Plant (KCP) located in Kansas City, Missouri. This review was conducted in 

accordance with SC&A’s Board-approved Standard Operating Procedure for Performing Site 

Profile Reviews (SC&A 2004). Under these guidelines, SC&A is charged with evaluating the 

approach set forth in the site profiles that is used in the individual dose reconstruction process. 

These documents are reviewed for their completeness, technical accuracy, adequacy of data, 

consistency with other site profiles, and compliance with the stated objectives, as defined in 

SC&A (2004). 

The following presents our findings. 

Finding 1: Without specific information regarding the chemical form and particle size 

distribution of uranium exposure experienced by a worker, dose reconstructors should use 

default assumptions regarding particle size and chemical form that result in the highest dose to 

the organ of concern. 

Finding 2: The bioassay data summarized in Table 12 of the site profile appear to be incomplete, 

which raises concerns regarding its use in developing a coworker model. 

Finding 3: SC&A believes that the default chronic pattern of intake used in the uranium 

coworker model, which apparently is being applied to all workers, may not apply to many 

workers. Our review of actual cases reveals that many workers have legible bioassay records 

and show patterns of excretion rates that indicate that the coworker model may not be claimantfavorable for all workers. 

Finding 4: The system used to categorize workers by administrative code for the purpose of 

implementing the coworker model might result in misassignments that result in underestimates 

of reconstructed doses. 

Finding 5: There appears to be limited information available to the dose reconstructor with 

respect to the nature of the work performed by the workers. This issue warrants further 

investigation, along with the investigation of the legibility/accuracy/completeness of the 

database(s) used for dose reconstruction, in order to assess the ability to reconstruct worker doses, 

as supplemented with the coworker model. 

Finding 6: It appears that there are large time periods where beta exposure records are lacking, 

making it difficult to reconstruct beta doses for workers during those time periods, and for 

developing a coworker model that can cover those time periods. In addition, the details of beta 

exposures are lacking. 

Finding 7: The scarcity of positive neutron doses might be explained, in part, by the limited 

ability of Neutron Track A (NTA) film to detect neutron energies below 1 MeV. Additionally, 

neutron exposures may have been missed during neutron area surveys, because the only neutron 
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survey instrument listed in Table 5 (ORAUT 2006, p. 13) is a Nuclear Chicago Model #2715, 

and this instrument may not have correctly responded to the pulsed neutron fields with the 

generator(s) being operated in the microsecond pulse mode, which was typical at KCP, as 

indicated in Table 4 (ORAUT 2006, p. 12). 

Finding 8: The fading of the NTA film as a function of time, temperature, and humidity was not 

addressed in the site profile, nor were there any correction factors provided. Lower-energy 

moderated neutrons would show even more fading, as compared to the higher-energy. 

Additionally, the angular response of NTA film and polycarbonate neutron dosimeters was not 

addressed, which generally requires a 30% correction factor. 

Finding 9: Neutron-to-Photon (n/p) ratios require additional investigation in order to develop a 

recommended approach for dose reconstructors. 

Finding 10: It may not be always correct to assume that unmonitored workers experienced 

exposures that were generally lower than those experienced by monitored workers, because 

monitoring in the early years may not have been as thorough as would be desired. In addition, as 

discussed in previous findings, coworker categories are ambiguous and might result in 

inappropriate coworker dose assignments. Furthermore, Table 15 may reflect decreased average 

recorded doses, as the number of zero dose records included may not be a complete accounting 

of the actual dose to workers. 

Finding 11: A correction factor for exposures to photon radiation might be needed, due to the 

differences between the actual photon energy distributions created largely by x-ray machines, 

and the relatively high-energy photons associated with Co-60, which was used for calibration of 

dosimeters. This issue is especially of concern regarding exposures to skin and shallow organs. 

An SC&A site visit was performed during the preparation of this report in order to supplement 

the information provided in the Site Research Database (SRDB). However, there is a need for 

additional data capture activities, including worker interviews, in order to complete our 

investigations. At the time of the preparation of this report, arrangements were being made for 

additional outreach activities. Upon completion of those activities, this report will be amended. 
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1.0 INTRODUCTION 

On January 1, 2006, the National Institute for Occupational Safety and Health (NIOSH) issued 

ORAUT-TKBS-0031, Site Profile for the Kansas City Plant, which provides data and guidance 

for dose reconstruction of workers at the Kansas City Plant (KCP) located in Kansas City, 

Missouri. This report presents a review of the site profile, as requested by the Advisory Board 

on Radiation and Worker Health (the Board) during the full board meeting held in Manhattan 

Beach, California, in February 2010. 

1.1 SCOPE OF THE REVIEW 

This review was conducted in accordance with SC&A’s Board-approved Standard Operating 

Procedure for Performing Site Profile Reviews (SC&A 2004). Under these guidelines, SC&A is 

charged with evaluating the approach set forth in the site profiles that is used in the individual 

dose reconstruction process. These documents are reviewed for their completeness, technical 

accuracy, adequacy of data, consistency with other site profiles, and compliance with the stated 

objectives, as defined in SC&A (2004). 

1.1.1 Objective 1: Completeness of Data Sources 

SC&A reviewed the site profile with respect to Objective 1, which requires SC&A to identify 

principal sources of data and information that are applicable to the development of the site 

profile. The three elements examined under this objective are (1) determining if the site profile 

made use of available data considered relevant and significant to the dose reconstruction, 

(2) investigating whether other relevant/significant sources are available, but were not used in the 

development of the site profile, and (3) determining if worker input was considered in the 

development of the site profile. 

1.1.2 Objective 2: Technical Accuracy 

Objective 2 requires SC&A to perform a critical assessment of the methods used in the site 

profile to develop technically defensible guidance or instructions, including evaluating field 

characterization data, source term data, technical reports, standards and guidance documents, and 

literature related to processes that occurred at KCP. The goal of this objective is to analyze the 

data according to sound scientific principles, and then evaluate this information in the context of 

dose reconstruction. 

1.1.3 Objective 3: Adequacy of Data 

Objective 3 requires SC&A to determine whether the data and guidance presented in the site 

profile are sufficiently detailed and complete to conduct dose reconstruction, and whether a 

defensible approach has been developed in the absence of data. In addition, this objective 

requires SC&A to assess the credibility of the data used for dose reconstruction. The adequacy 

of the data identifies gaps in the facility data that may influence the outcome of the dose 

reconstruction process. For example, if a site did not monitor all workers exposed to neutrons 

who should have been monitored, this would be considered a gap and thus an inadequacy in the 

data. An important consideration in this aspect of our review of the site profile is the scientific 
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validity and claimant-favorability of the data, methods, and assumptions employed in the site 

profile to fill in data gaps. 

1.1.4 Objective 4: Consistency among Site Profiles 

Objective 4 requires SC&A to identify common elements within site profiles completed or 

reviewed to date, as appropriate. In order to accomplish this objective, the KCP Technical Basis 

Document (TBD) was compared to other TBDs, particularly those referenced in the site profile 

and those related to frequently visited facilities. This assessment was conducted to identify areas 

of inconsistencies and determine the potential significance of any inconsistencies with regard to 

the dose reconstruction process. 

1.1.5 Objective 5: Regulatory Compliance and Quality Assurance 

Objective 5 requires SC&A to evaluate the degree to which the site profile complies with stated 

policy and directives contained in 42 CFR Part 82. In addition, SC&A evaluated the TBD for 

adherence to general quality assurance policies and procedures utilized for the performance of 

dose reconstructions. 

SC&A’s draft report and preliminary findings will subsequently undergo a multi-step resolution 

process. Resolution includes a transparent review and discussion of draft findings with members 

of the Advisory Board Work Group, petitioners, claimants, and interested members of the public. 

Prior to and during the resolution process, the draft report is reviewed by the U.S. Department of 

Energy (DOE), Office of Health, Safety, and Security, to confirm that no classified information 

has been incorporated into the report. 

The NIOSH KCP site profile contained information and references that led to the discovery of 

additional information that was not addressed in the site profile. SC&A review efforts included a 

data capture plan and a keyword data search of DOE records. Analysis of the search results 

identified 50 boxes of unclassified site records of potential interest at the National Archives and 

Records Administration (NARA) Federal Records Center (FRC) in Lenexa, Kansas, and 200 

additional boxes of indeterminate classification status at the KCP National Nuclear Security 

Administration (NNSA) site. A scanning level review of the 50 boxes of unclassified records 

revealed a significant number of dose reconstruction-related records that were subsequently 

added to the SRDB. SC&A is planning to review the 200 boxes at the site in the near future. A 

number of former workers from the Bannister Complex (including NNSA and non-NNSA 

workers) were identified for interview purposes as well. SC&A is in the process of verifying the 

unclassified interviews with non-NNSA workers and intends to schedule future interviews with 

former and current NNSA workers. 
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1.2 REPORT ORGANIZATION 

In accordance with directions provided by the Advisory Board and with site profile review 

procedures prepared by SC&A and approved by the Advisory Board, this report is organized into 

the following sections: 

 Executive Summary 

 Introduction 

 Background Information 

 Occupational Medical Dose 

 Occupational Environmental Dose 

 Internal Dose 

 External Dose during Operations 
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2.0 BACKGROUND INFORMATION 

2.1 SUMMARY OF THE HISTORY OF KANSAS CITY PLANT (KCP) 

OPERATIONS 

As described in Section 2 of the site profile, the KCP has its origins as a World War II facility to 

assemble engines for navy planes, and continues to operate today in the fabrication of nonnuclear components for the nuclear weapons programs. Many aspects of KCP’s testing and 

manufacturing programs in support of the fabrication of weapons involved the use of uranium, 

radiation sources, and x-ray facilities, and the plant has maintained a formal radiation protection 

program since 1958. Tables 2, 3, and 4 of the site profile present categories of KCP activities 

and descriptions of radiation sources and electronic devices that could have resulted in internal 

and external exposures. These activities involve handling of uranium oxide powders, industrial 

x-ray units, x-ray devices for the measurement of the density and thickness of components, 

neutron generators and neutron sources, Cs-137 and Co-60 for radiography and testing of 

components, and beta-emitting sources for gauges. There were also other types of electronic 

equipment with the potential to cause external exposures to x-rays, such electron beam welders. 

2.2 DESCRIPTION OF KCP’S RADIATION PROTECTION PROGRAM 

Sections 2.5 and 2.6 of the site profile describe the radiation protection program at KCP, which 

was first described in 1964. Table 5 presents a listing of radiation detection equipment, and 

Section 2.6 summarizes the radiological records maintained for about 4,400 workers. The 

following summary of the records was extracted directly from page 13 of the site profile. 

• Positive deep, shallow, and extremity doses were first recorded in 1950. 

• Positive neutron doses were first recorded in 1966. 

• Before about 1959, the recorded deep and shallow doses were essentially 

equal. 

• Recorded extremity dose was higher in 1951 and 1952 than in any other year. 

• Relatively high shallow dose (in comparison with deep dose) was recorded 

from 1959 to 1964 and during 1973. 

• Recorded neutron dose is typically equal to recorded deep dose and to 

recorded shallow dose. The shallow dose is typically equal to the deep dose. 

• There are comparatively few records with positive neutron dose. 

• The only years with recorded positive uranium bioassay results are 1959 to 

1971. 
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3.0 OCCUPATIONAL MEDICAL DOSE 

Section 3.0 of the site profile describes the occupational medical exposures experienced by 

workers, which apparently has a long history beginning with routine chest x-rays in 1949. 

Detailed instructions are provided for reconstructing occupational medical exposures, drawing 

heavily from ORAUT-OTIB-0006 (ORAUT 2005) and making use of historical records that 

provide the type of frequency of medical x-ray examinations for different categories of worker. 

SC&A has previously reviewed OTIB-0006, and we have no comments on this section of the site 

profile. 

 
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4.0 OCCUPATIONAL ENVIRONMENTAL DOSE 

Section 4 and Appendix A of the site profile address the reconstruction of occupational 

environmental dose. In order to place an upper bound on potential occupational environmental 

exposures experienced by unmonitored workers, the site profile uses the simplifying assumption 

that the average annual airborne concentration of uranium outdoors is equal to 1% of the median 

indoor concentration, as provided in Table 11 of the TBD (i.e., 5.49E-13 μg/cm3). As described 

in Attachment A to the TBD, this rule of thumb is a screening methodology recommended in 

NCRP Report No. 123, Screening Models for Releases of Radionuclides to Atmosphere, Surface 

water, and Ground (NCRP 1996). SC&A agrees with this basic strategy for bounding the 

average annual outdoor airborne concentrations of uranium and their associated doses. 

Attachment A of the site profile also addresses the airborne concentration of depleted uranium 

(DU) that might have been experienced by workers on the roof working near the airborne 

effluent release point. The site profile concludes that the 1% rule of thumb also works for these 

workers. When one considers building wake effects, along with the fact that such workers would 

not have been involved in maintenance work close to the effluent release point for extended 

periods of time, and the fact that the wind direction varies, it seems unlikely that even these 

workers would experience protracted exposures in excess of 0.01 of the indoor airborne 

concentrations of uranium. 

Based on the above discussion, we concur with the approach used in the site profile to derive 

occupational environmental doses.
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5.0 INTERNAL DOSE 

This section presents a brief description of the material provided in the site profile with respect to 

the type of operations that took place at KCP and the type of data that are available for 

reconstructing internal exposures at the facility. This is followed by a description of the 

instructions provided in the site profile for reconstructing internal exposures, and a critical 

review of those instructions and the data upon which they are based. 

5.1 INTRODUCTION AND OVERVIEW 

Section 5.0 of the site profile describes the data available and the methods for performing 

internal dose reconstructions at KCP. As described in Section 5, from 1958 through about 1971, 

the primary source of internal exposure was machining items containing DU oxide. The site 

profile also explains that, after 1971, operations changed and the potential for internal exposure 

to uranium became minimal because the process did not result in airborne uranium. In addition, 

the site profile explains that the potential for internal exposure to other sources of radionuclides 

is also considered minimal because the other sources, such as Cs-137 and Co-60, were sealed. 

5.2 URANIUM 

Uranium oxide (UO2) was ordered by KCP in 10,000-lb lots and had the mass and radiological 

characteristics described in Table 9 of the site profile. One of the more important parameters 

describing the uranium is that the powder used to make the uranium had an activity median 

aerodynamic diameter (AMAD) of 1.175 microns and a geometric standard deviation (GSD) of 

2.48. However, the site profile explains that there is uncertainty regarding the particle size 

distribution of the aerosols of uranium produced during machining. 

Table 10 of the site profile provides information on the gross alpha contamination levels on 

surfaces in various locations at the KCP, as measured from 1962 to 1969. Both average and 

maximum contamination levels are presented in units of dpm/100 cm2; presumably the values 

refer to removable contamination. Table 11 of the site profile presents statistical data 

characterizing the airborne DU concentration in units of μCi/m3

 from 1958 through 1970. These 

data are all useful for the purpose of deriving internal doses from uranium. 

Most importantly, the site profile indicates that there are bioassay records for individual workers 

written on cards, but the site profile states that these are nearly illegible. The implications are 

that it might not be possible to reconstruct uranium intakes for individual workers based on their 

personal bioassay records. However, electronic data in the form of statistical summaries of the 

individual records are available in the Site Research Database (SRDB), which can be used to 

build a coworker model. The following describes the coworker model developed in the site 

profile to support dose reconstruction for workers that were not monitored or whose records are 

illegible. 

Section 5.1.3 of the site profile presents statistical data in electronic bioassay records 

characterizing the concentrations of uranium in urine samples collected from workers from 1959 

through 1971 expressed in units of μg/L, and the associated derived inhalation rates expressed in 
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units of pCi/day. The site profile explains that NIOSH assumed that the minimum detectable 

level (MDL) was 10 μg/L, which is presumably used to derive missed dose. The site profile also 

explains that the frequency of bioassay sampling varied for different individuals and time periods. 

These data are provided in Table 12 of the site profile, which is reproduced here as Table 1 

because of its importance to dose reconstruction. 

Table 1: Statistical Parameters of Recorded DU in Urinea

Recorded Annual Urine Concentrationb Lognormal Fit

Concentration (μg/L) Concentration (μg/L) Chronic Intakes (pCi/d)c

Year No. of Workers 

Reported Mean Maximum Median GSD 5th Median 95th

1959 214 4.125 52.60 2.642 2.675 1.05E+02 6.42E+02 3.92E+03 

1960 281 36.58 140. 19.53 3.813 7.79E+02 4.75E+03 2.89E+04 

1961 123 51.40 192.1 37.44 2.402 1.49E+03 9.10E+03 5.55E+04 

1962 148 4.327 15.75 3.162 2.508 1.26E+02 7.69E+02 4.69E+03 

1963 211 10.96 72.00 7.564 2.532 3.02E+02 1.84E+03 1.12E+04 

1964 219 5.627 78.38 3.888 2.431 1.55E+02 9.46E+02 5.76E+03 

1965 175 9.572 38.00 5.583 3.422 2.23E+02 1.36E+03 8.27E+03 

1966 223 6.432 45.05 4.214 2.640 1.68E+02 1.02E+03 6.24E+03 

1967 159 5.438 21.50 3.574 2.713 1.43E+02 8.69E+02 5.30E+03 

1968 11 6.055 6.600 6.052 1.029 2.42E+02 1.47E+03 8.97E+03 

1969 1 0.15 0.150 0.150 1.000 5.99E+00 3.65E+01 2.22E+02 

1970 59 11.64 45.00 7.576 2.686 3.02E+02 1.84E+03 1.12E+04 

1971 47 0.03596 0.1000 0.02993 1.903 1.19E+00 7.28E+00 4.44E+01 

ALL 1,871 14.1 192.1 5.5 4.7 

a. All bioassay measurements. 

b. The recorded annual sum of urine concentration is the sum of all bioassay results for the year. There is one sum 

for each person-year record. The listed statistics are based on the analysis of the data, which are the sums of all 

bioassay data for every person for that year. 

c. Chronic intakes that produce the urinary excretion per day on the 365th day of intakes corresponding to the 

median excretion from the lognormal fit, and 5th and 95th percentile intakes using a GSD of 3. Assumes 5-

micron (μm) AMAD particle size; intakes for 1-μm AMAD particle size, 10.97 g/cm3

 density, and absorption 

Type S are smaller. 

Source: ORAUT-TKBS-0031, Table 12 (ORAUT 2006) 

The footnotes provide important information. Specifically, footnote b indicates that the tabulated 

concentrations are based on the sums of all bioassay results for a given year. Presumably this 

means that in 1959, there were 214 workers with reported bioassay samples and, if you added up 

the uranium concentrations observed in urine samples for each worker and divided by the 

number of samples collected in that year for that worker, you would get the average annual 

uranium concentrations in the urine of 214 workers for 1959. Then you would simply report the 

maximum, average, median, and GSD of this population of 214 values. Using these values, 

chronic intake rates are derived by estimating the chronic intake rate that would give you the 

indicated concentration of uranium in urine on the last day of that year. 

Footnote b and the accompanying text state that the intake rates were based on an assumed 

5-micron AMAD and Type S uranium, because these assumptions result in higher intake rates 

than if 1-micron AMAD or other than Type S is assumed when calculating intake rates based on 

measured uranium concentrations in urine. We agree with this strategy. However, as discussed 

below, we have some concerns regarding the assumption that the intakes were chronic. 
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Table 13 of the site profile provides the number of bioassay measurements and the total and 

average uranium concentrations in urine sorted by occupational description over the years 1959 

to 1971. If a dose reconstruction is being performed for a worker with a known job category, 

this table could help in assigning intakes to unmonitored workers or for workers whose bioassay 

records are illegible. 

Given this information, Section 5.1.4 of the site profile provides guidance on deriving internal 

doses to uranium using the above-described tables. The site profile instructs the dose 

reconstructor to try to assign each worker undergoing dose reconstruction to one of the following 

four categories (ORAUT 2006, p. 22): 

(1) workers routinely exposed to airborne or loose material, (2) workers 

occasionally exposed, (3) workers rarely exposed or exposed only to very low 

workplace airborne or contamination levels, and (4) workers with little or no 

potential for radiological exposure. Unmonitored workers in category 1 should 

be assigned the 95th percentile intakes; category 2 to the median intakes; category 

3 to the 5th percentile intakes; and category 4 workers should be assigned internal 

exposures per the environmental section of this document. 

Given the above description of the coworker model, which apparently is intended to be used for 

most, if not all, workers due to the illegibility of the individual worker records, the following 

presents SC&A’s review of the coworker model and the data upon which it is based. 

5.2.1 Powder Activity Median Aerodynamic Diameter 

The KCP had substantial quantities (10,000-lb lots) of UO2 onsite at various times. Machining 

and grinding of DU metal creates fine dust available for intake by workers, and NIOSH states 

that (ORAUT 2006, p. 18): 

In fitting bioassay data, dose reconstructors may wish to start with a 1-μm AMAD, 

a GSD of 2.5, a density of 10.97 g/cm3

, a lung solubility Type S, and f1 of 0.002 

(ICRP 1995). However, it is not known what impact processes at KCP had on the 

particle size of uranium. Use of the default 5-μm AMAD particle size is also 

acceptable unless it is known that the intake was of unaltered UO2 powder. 

(Emphasis added.) 

SC&A evaluated internal doses associated with inhaling uranium and determined that, since the 

Atomic Weapons Employer (AWE) activities at KCP involved handling substantial quantities of 

UO2 powder, it does not appear to be appropriate to use the default option of 5-μm AMAD. 

Without specific information regarding the chemical form and particle size distribution 

experienced by a worker, dose reconstructors should use combinations of 1- and 5-μm AMAD 

and Types M and S uranium, and use those assumptions that result in the highest dose to the 

organ of concern. 

Finding 1: Without specific information regarding the chemical form and particle size 

distribution of uranium exposure experienced by a worker, dose reconstructors should use 
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default assumptions regarding particle size and chemical form of uranium that result in the 

highest dose to the organ of concern. 

5.2.2 Annual Sum of Bioassay Measurements 

 

The KCP has developed and maintained a radiological records database that contains records for 

all monitored worker exposures at KCP for all years of record. According to NIOSH (ORAUT 

2006), the database contains exposure data for about 4,400 workers. Page 19 of the site profile 

states the following: 

The available data are shown on an annual basis and might be the sum of one or 

more bioassay measurements. If the individual case information does not yield 

additional information, dose reconstructors should make the claimant favorable 

assumption that the recorded bioassay quantities represent a single bioassay 

measurement taken at the end of the calendar year. 

SC&A reviewed the files of 528 claimants (see Table 2), and 50 of these workers had uranium 

results. Table 2 presents the results of that review. We found that in each year, there were 

various unreadable results, but the majority of the results, with the exception of 1970, were 

legible. The point we would like to make is that the site profile leaves the reader with the 

impression that it is not plausible to perform dose reconstructions using the workers’ bioassay 

data, but instead appears to recommend the use of the coworker model described above. In fact, 

our review found that it is possible to reconstruct the internal exposures of workers to uranium 

using the workers’ bioassay results. We suggest that the site profile make it clear that the 

workers’ bioassay records should be used when available. 

Observation: The site profile should state that the coworker model should be used when it 

is not possible to use the workers’ bioassay records, presumably because they are illegible, 

incomplete, or lacking. 

Table 2: Claimant File Review of Uranium Bioassay 

Year No. of Workers Excretion Rates 

(μg/L ) 

Max excretion rate 

(μg/L ) Total No. Samples 

1959 8 0–3.9 3.9 32 

1960 11 0–10 72 28 

1961 4 0–20 70 8 

1962 5 0–1.5 4.3 5 

1963 7 Not reported 16.5 11 

1964 9 Not reported 5.3 12 

1965 11 Not reported 16.5 16 

1966 14 Not reported 13 21 

1967 11 Not reported 20 16 

1968 4 0 6 5 

1969 6 0 0.6 7 

1970 10 0–14 25 10 

1971 3 0 0 3 

Notes: Frequency of monitoring not related to results. 

 Frequency did not increase after high result. 
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5.2.3 Bioassay Coworker Model 

Table 12 of the site profile (p. 20), which summarizes the electronic bioassay records, shows 

only one worker with a bioassay result in 1969. However, SC&A’s review of the records upon 

which Table 12 is based reveals that six workers among the claimant group had bioassay records 

in 1969. Consequently, Table 12 appears to be incomplete, which raises questions regarding the 

use of the data in Table 12 as the basis for a coworker model. 

Finding 2: The bioassay data summarized in Table 12 of the site profile appear to be 

incomplete, which raises concerns regarding its use in developing a coworker model. 

5.2.4 Chronic Uranium Intake 

For the purpose of reconstructing internal exposures using the coworker model, the site profile 

presumes that intakes of uranium dust are chronic. The derivation of chronic intake rates based 

on the sums of individual results in a year may result in a less-than-favorable dose reconstruction 

for some workers. Our analysis of the claimant data has shown that some workers have high 

results in 1 month, followed by very low results at the following sampling period. For example, 

one worker had 3 low results in 1959, on the order of 2 μg/L. The worker’s results were below 

the MDL in 1960, 30 μg/L in January, below the MDL in February, 72 μg/L in May, and 0 in 

July and December. This pattern of excretion rate results is not characteristic of chronic intakes, 

and averaging concentrations in urine to obtain an average annual chronic intake rate would 

result in an underestimate of internal exposures. 

The pattern of high results was not uniform among workers. In 1960, another worker presented 

the following excretion rate results: 0 in January, 14 μg/L in February, 10 μg/L in April, and 

42 μg/L in December. This same worker in 1961 presented 20 μg/L in June and 70 μg/L in 

December. A third worker in 1961 had a result equal to 0 in August and a result equal to 

20 μg/L in December. 

In addition, document SRDB 049002 (Nasca 2005) contains uranium bioassay results of a 

worker in 1960, which presented the following results: 0 in January, 29 μg/L in February, 0 in 

April, 39 μg/L in May, and 66 μg/L in December. In the same document, a worker presented the 

following results in 1960: 35 μg/L in January; 0 in February, April and May; followed by 20 

μg/L in September; and 0 in December. Those results are not characteristic of chronic intakes. 

Finding 3: SC&A believes that the default chronic pattern of intake used in the uranium 

coworker model, which apparently is being applied to all workers, may not apply to many 

workers. Our review of actual cases reveals that many workers have legible bioassay 

records and show patterns of excretion rates that indicate that the coworker model may not 

be claimant favorable for all workers. 

In addition to issues related to Table 12 of the site profile, we also have concerns regarding the 

way in which the site profile categorizes unmonitored workers for the purpose of implementing 

the coworker model. On page 22, workers are grouped into the following four exposure 

categories: (1) workers routinely exposed to airborne or loose material, (2) workers occasionally 
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NOTICE:

exposed, (3) workers rarely exposed or exposed only to very low workplace airborne or 

contamination levels, and (4) workers with little or no potential for radiological exposure. 

SC&A is concerned that the use of Table 13 of the site profile and this system to categorize 

workers might lead to less than claimant-favorable dose reconstructions. For example, our 

review of the SRDB revealed that administrative support/clerical/work planner Occupational 

Code Category 450 has a relatively high average bioassay measurement. Specifically, Document 

SRDB 15925 (Traub 2005) contains an e-mail from Richard Traub to Brent M. Nasca asking 

about the high excretion rates of code 450. Nasca’s response was that this category includes not 

only secretaries with no expected exposures, but also work planners (Nasca 2005). The work 

planners are expected to show uranium uptakes. Thus, workers with a high potential of 

exposures are classified in the same code as workers not expected to have any exposures to 

uranium. 

Finding 4: The system used to categorize workers by administrative code for the purpose 

of implementing the coworker model might result in misassignments that result in 

underestimates of reconstructed doses. 

5.3 OTHER RADIONUCLIDES 

Section 5.2 of the site profile addresses internal exposures other than uranium, explaining that 

there were no other significant worker intakes other than uranium. SC&A concurs with this 

position. However, a site visit would help to confirm that this conclusion is valid.
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6.0 EXTERNAL DOSE DURING OPERATIONS 

This section presents a brief description of the material provided in the site profile with respect to 

the type of operations that took place at KCP and the type of data that are available for 

reconstructing occupational external exposures at the facility. This is followed by a description 

of the instructions provided in the site profile for reconstructing external exposures, and a critical 

review of those instructions and the data upon which they are based. 

6.1 BACKGROUND 

Section 6.0 of the site profile, which addresses external radiation exposures at KCP, explains that 

the sources of external exposure at KCP were primarily associated with fabrication and quality 

control testing of non-nuclear weapons components, and that clear descriptions of those activities 

are not readily available due to their classified nature. However, Table 3 of the site profile lists 

the external radiation sources at KCP, and Table 4 lists the radiation generating devices (RGDs), 

which consisted of beta, gamma, x-ray, and neutron emitting/generating sources. Section 6.3 of 

the site profile describes the dosimeter technology that was used to record worker exposure to 

photon, beta, and neutron exposures associated with the variety of sources, and RGDs used at 

KCP over the years. This section reviews the data, models, and assumptions used in the site 

profile to reconstruct external exposures to KCP workers. 

As explained in the site profile, because of its long history, a variety of personnel dosimetry 

devices were employed over the years, and an effort was made in the site profile to compare 

these different methods, so that dose reconstructions for different time periods can be performed 

in terms of a common metric, namely Hp(10) for penetrating dose and Hp(0.07) for nonpenetrating dose. 

Section 6.4 presents the methods recommended in the site profile to perform external dose 

reconstruction. Section 6.4.1 explains that external dosimetry exists for most workers, but some 

workers were not monitored. The site profile takes the position that workers who were not 

monitored experienced exposures that generally were lower than those experienced by monitored 

workers. This might be true in general, but it might not apply to all workers. Figure 2 of the site 

profile presents a statistical analysis of the annual penetrating dose experienced by all workers as 

compiled by NIOSH for 1950 through 2003. Also, Table 15 of the site profile presents a 

statistical analysis of the exposures for each year from 1950 through 1990. Because of its 

importance, Table 15 is reproduced here as Table 3: 

Table 3: Statistical Parameters of Recorded Penetrating Annual Doses 

Arithmetic, All Recorded Dose Lognormal, dose>0

Year No. of Dose, rem Dose, rem

Workers Mean Maximum

No. of 

Workers Median 95% GSD

1950 46 7.09E-02 6.47E-01 29 5.01E-02 5.54E-01 4.31E+00 

1951 227 2.78E-01 5.32E+00 158 4.97E-02 2.02E+00 9.52E+00 

1952 233 1.91E-01 5.90E+00 220 2.45E-02 7.42E-01 7.96E+00 

1953 103 1.37E-01 5.32E+00 72 2.13E-02 4.50E-01 6.38E+00 

1954 65 1.61E-01 2.99E+00 21 1.19E-01 4.74E+00 9.39E+00 

1955 41 9.18E-02 4.18E-01 25 1.10E-01 4.59E-01 2.39E+00 
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Table 3: Statistical Parameters of Recorded Penetrating Annual Doses 

Arithmetic, All Recorded Dose Lognormal, dose>0

Year No. of Dose, rem Dose, rem

Workers Mean Maximum

No. of 

Workers Median 95% GSD

1956 26 2.89E-01 1.75E+00 26 1.35E-01 1.07E+00 3.52E+00 

1957 65 5.24E-01 7.89E+00 36 1.77E-01 6.33E+00 8.80E+00 

1958 301 3.90E-02 8.43E-01 89 5.44E-02 4.84E-01 3.78E+00 

1959 464 8.97E-03 2.30E-01 72 3.57E-02 1.78E-01 2.66E+00 

1960 1,043 1.21E-02 1.35E+00 165 4.53E-02 2.31E-01 2.70E+00 

1961 948 2.39E-02 5.90E-01 400 3.17E-02 1.64E-01 2.72E+00 

1962 700 1.25E-02 1.65E+00 59 4.25E-02 4.53E-01 4.22E+00 

1963 597 1.18E-02 1.63E+00 100 3.65E-02 2.02E-01 2.83E+00 

1964 530 6.85E-03 6.90E-01 59 3.09E-02 1.97E-01 3.08E+00 

1965 436 1.35E-03 8.00E-02 26 1.66E-02 5.59E-02 2.09E+00 

1966 415 2.32E-03 2.00E-01 27 2.54E-02 8.95E-02 2.15E+00 

1967 370 1.71E-03 2.50E-01 20 2.06E-02 7.14E-02 2.13E+00 

1968 469 1.75E-03 3.50E-01 5 1.10E-01 6.84E-01 3.04E+00 

1969 577 (a) 0.00E+00 0 

1970 580 1.60E-03 3.20E-01 29 1.61E-02 7.47E-02 2.54E+00 

1971 575 9.39E-04 2.00E-01 16 2.02E-02 9.09E-02 2.50E+00 

1972 195 1.19E-02 4.26E-01 68 2.04E-02 8.61E-02 2.40E+00 

1973 199 9.86E-02 1.81E+01 69 1.87E-02 1.09E-01 2.91E+00 

1974 169 1.30E-02 8.80E-02 67 2.86E-02 6.89E-02 1.71E+00 

1975 150 5.72E-03 8.60E-02 44 1.25E-02 5.96E-02 2.58E+00 

1976 126 9.65E-03 2.48E-01 53 1.37E-02 7.34E-02 2.77E+00 

1977 123 5.45E-03 3.00E-01 12 2.76E-02 1.72E-01 3.04E+00 

1978 152 7.53E-03 1.25E-01 18 4.55E-02 2.25E-01 2.64E+00 

1979 162 2.69E-03 8.30E-02 17 2.12E-02 5.64E-02 1.81E+00 

1980 185 4.19E-03 1.33E-01 22 2.74E-02 8.49E-02 1.99E+00 

1981 210 4.12E-03 1.20E-01 24 2.72E-02 9.27E-02 2.11E+00 

1982 209 2.00E-03 5.20E-02 22 1.67E-02 3.72E-02 1.63E+00 

1983 226 2.98E-03 3.14E-01 12 2.76E-02 2.06E-01 3.39E+00 

1984 216 1.89E-02 3.57E+00 18 2.44E-02 2.80E-01 4.41E+00 

1985 201 4.67E-02 8.66E+00 49 1.41E-02 8.34E-02 2.95E+00 

1986 194 3.22E-03 5.50E-02 27 2.05E-02 4.71E-02 1.66E+00 

1987 196 1.65E-03 4.00E-02 20 1.18E-02 4.82E-02 2.35E+00 

1988 188 3.52E-03 1.80E-01 11 4.62E-02 1.81E-01 2.29E+00 

1989 233 8.03E-04 1.60E-02 17 1.09E-02 1.37E-02 1.15E+00 

1990b 217 1.16E-03 4.10E-02 17 1.37E-02 2.50E-02 1.44E+00 

a. Recommend using values for 1968. All 1969 recorded doses = zero. 

b. Recommend using values for 1990 for all subsequent years. 

Source: ORAUT-TKBS-0031, Table 15 (ORAUT 2006) 

Given these data, the site profile makes the following recommendation: 

Dose reconstructors should assign the ambient environmental dose to an 

unmonitored worker with minimal potential for radiation exposure from KCP 

operations, median coworker dose to an unmonitored worker with minimal 

likelihood of actual workplace exposure and the 95th percentile coworker dose to 

workers with a potential for workplace radiation exposure for each year of 

employment without a recorded dose. There should not, typically, be a significant 
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neutron exposure of unmonitored workers because sources of neutron radiation 

were very limited. 

The following presents SC&A’s review of the data and the instructions provided in the site 

profile. 

 

6.1.1 Accuracy/Completeness of Dose Records 

Page 13 of the site profile (ORAUT 2006) states that: 

KCP has developed and maintained a radiological records database that contains 

records for all monitored worker exposures at KCP for all years of record. The 

database contains exposure data for about 4,400 workers. 

Dose reconstructors should use recorded doses from the KCP database to 

supplement the hard-copy original dosimeter processing information submitted by 

DOE because the respective claims are often difficult to read. 

SC&A’s review of several KCP claimant files on the NOCTS database indicates that some of the 

original dose records are indeed difficult to read, if not illegible. Apparently, there are hard 

copies and an electronic KCP database that contain the dose records for the workers; however, 

the accuracy and completeness of neither data source was addressed in the site profile. From the 

hardcopies examined of a limited number of claimant records, it would be difficult to decipher 

the correct recorded dose, and sometimes the dates, bringing into question the accuracy of the 

electronic database, if it was populated from the hardcopy records. 

SC&A searched the 731 KCP claims on the NOCTS database using occupation descriptions that 

may indicate potential exposure, such as mechanics/repairers, machinists and engineers 

contained in Table 13 of the KCP site profile. SC&A scanned 61 of these cases for DOE 

external dose files and found that 14 cases contained external exposure records. It was found 

that for most of these 14 cases, the external dose records only had one sheet of data, generally 

listing dose for only 1, 2, or 3 years (maximum of 7 years). This information is summarized in 

Figure 1 below. 

5

1950 1955 1960 1965 1970 1975 1980 1985 1990 1995 2000 2005 2010

Records during year

4

3

2

1

0

Figure 1: Number of External Exposure Records during a Given Year for 

14 Cases with Records 
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Some workers had the same job title for many years, and the work period covered a wide range 

from 1951 to the present. It seems highly unlikely that workers (of those analyzed) would be 

monitored for only a year or two if they were performing the same task for many years. 

Additionally, as shown in Figure 1, the external dose records of these 14 cases seem to be 

centered around the mid-1960s with very few outside that time period. 

Finding 5: There appears to be limited information available to the dose reconstructor 

with respect to the nature of the work performed by the workers. This issue warrants 

further investigation, along with the investigation of the legibility/accuracy/completeness of 

the database(s) used for dose reconstruction, in order to assess the ability to reconstruct 

worker doses, as supplemented with the coworker model. 

6.1.2 Beta Dose 

Page 25 of the site profile indicates that beta dose was measured from 1950–1964. However, 

prior to 1964, exposure record forms did not have a column to enter beta dose. Table 3 (ORAUT 

2006, p. 11) covers 1964–1987 and not the entire period (1958–1972 and 1997) of DU 

operations, which could involve beta exposure. 

The geometry of the worker’s body parts with respect to the radiation source was not described. 

The use of gloveboxes/fume hoods was not mentioned; these fixtures would alter the dose 

received to the different organs in comparison to the badge worn on the chest. Sufficient details 

concerning the potential for beta exposure from the various electron-producing and beta-emitting 

sources, as a function of time and work location, are lacking in the TBD. 

Finding 6: It appears that there are large time periods where beta exposure records are 

lacking, making it difficult to reconstruct beta doses for workers during those time periods 

and for developing a coworker model that can cover those time periods. In addition, the 

details of beta exposures are lacking. 

6.1.3 Moderated Neutron Dose 

The site profile states that neutron generators (D-T producing 14.7 MeV mono-energetic 

neutrons) and radioisotope neutron sources (PuBe producing an average energy of 4.5 MeV 

neutrons) were used at the KCP from 1960s to 2004; additionally, these neutron sources are 

listed in Table 4 of the site profile (ORAUT 2006, p. 12). NTA film and polycarbonate neutron 

dosimeters can be calibrated to these medium-energy neutron sources in the energy range of 

1 MeV to 15 MeV; however, for any occupied working area, there will be neutron shielding 

consisting of moderating (hydrogenous) material between the neutron source and the workers, 

which degrades the neutron energy and creates gamma radiation from neutron-capture reactions. 

Some of these degraded neutrons will be below the ~1 MeV thresholds of the NTA film and 

polycarbonate. 

SC&A considers this an unregistered dose that would not be recorded on the workers’ records. 

If a significant fraction of the dose is less than 1 MeV, there will not be a detectible neutron dose 
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recorded, when an actual neutron dose was received. This may partly account for the NIOSH 

statement (ORAUT 2006, p. 27): 

Overall, the recorded neutron dose is a relatively insignificant component of the 

worker dose. 

NIOSH does not provide any information (as a function of time) concerning the physical setup, 

shielding, operating parameters (neutron output and usage fraction), and specific use of the 

generated neutron fields to allow for an evaluation of the potential neutron exposures to the 

workers. Documentation providing benchmark neutron exposure surveys would be helpful in 

assessing the potential neutron exposures. Additionally, job titles for the workers that may have 

potentially been exposed to neutrons are necessary to evaluate the recorded neutron dose records, 

and to also assist the dose reconstructor in looking for, and assigning, neutron doses during the 

dose reconstruction process. 

Finding 7: The scarcity of positive neutron doses might be explained, in part, by the 

limited ability of NTA film to detect neutron energies below 1 MeV. Additionally, neutron 

exposures may have been missed during neutron area surveys, because the only neutron 

survey instrument listed in Table 5 (ORAUT 2006, p. 13) is a Nuclear Chicago Model #2715, 

and this instrument may not have correctly responded to the pulsed neutron fields with the 

generator(s) being operated in the microsecond pulse mode, which was typical at KCP, as 

indicated in Table 4 (ORAUT 2006, p. 12). 

6.1.4 Neutron Dosimetry Correction Factors 

Section 6.3.2 of the site profile describes the personal neutron dosimetry systems employed at 

the KCP, including techniques and exchange frequencies provided in Table 14 (ORAUT 2006, 

p. 25). One of our concerns is that quarterly exchange of NTA film can result in complete loss 

of countable track and yield 0 dose recordings for low-level and/or low-energy neutron 

exposures. This is illustrated in a 1974 article by L. Phillips (Phillips 1974, pdf p. 18), which 

describes tests run at Brookhaven National Laboratory (BNL) to determine NTA track fading. 

The results, using a relatively high-energy bare PuBe neutron source, are shown in Figure 2. 
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Figure 2: Percent of Original Tracks vs. Time 

Finding 8: The fading of the NTA film as a function of time, temperature, and humidity, 

was not addressed in the site profile, nor were there any correction factors provided. 

Lower-energy moderated neutrons would show even more fading as compared to the 

higher-energy neutrons. Additionally, the angular response of NTA film and 

polycarbonate neutron dosimeters was not addressed, which generally requires a 30% 

correction factor. 

6.1.5 Neutron-to-Photon Ratios 

Page 27 of the site profile (ORAUT 2006) states the following:

KCP worker recorded positive neutron dose was recorded a total of 35 times over 

a period from 1966 through 1996, with most instances occurring in the 1980s 

with good dosimetry capabilities, from a total of 14,758 annual dose records. In 

all cases, except for 2, the recorded annual deep dose is equal to the recorded 

annual neutron implying all recorded deep dose resulted from the neutron 

dose. ... As such, the recommended approach is to use a neutron to photon dose 

ratio of 1:1 as a conservative estimate of neutron dose to the few workers with 

any potential of neutron exposure. 

In light of concerns regarding the reliability of NTA film with respect to lower-energy neutrons, 

it is not apparent that there is a sound basis for assigning a n/p ratio of 1:1. In other site profile 

reviews, SC&A has stated that n/p ratios can be used to derive neutron doses if a reliable set of 

paired data of neutron and photon measurements are available and which employed instruments 

that can detect the full range of neutron energies. It does not appear that this approach was used 

to derive the n/p ratio of 1:1. 
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Finding 9: Neutron-to-Photon (n/p) ratios require additional investigation in order to 

develop a recommended approach for dose reconstructors. 

6.2 COWORKER DATA ISSUES 

Page 26 of the site profile (ORAUT 2006) states the following: 

...it is reasonable to assume that any unmonitored dose would be less than the 

dose received by monitored workers. 

Figure 2 of the site profile, which presents a lognormal probability plot of KCP recorded annual 

penetrating dose (ORAUT 2006, p. 27), shows the probability of occurrence versus the annual 

dose (mrem) for 1950–2003. This plot indicates a median dose of around 20 mrem/year and a 

95th percentile of around 70 mrem/year. Table 15 (ORAUT 2006, p. 28) provides a list of 

coworker doses as a function of year for the period of 1950–1990. There appears to be a 

reasonable amount of data available for this coworker model. However, it would be useful to 

obtain a spreadsheet of the data in Table 15 to allow creation of a plot consisting of dose versus 

year to better visualize trends and abnormalities in the data. 

Table 15 also shows that there were 577 workers monitored during 1969, with all 0 recorded 

doses. This appears to be unusual, because the adjacent years had approximately the same 

number of workers monitored with the median and 95th percentile doses both positive. To use 

the information in Table 15 as coworker data, the reason for the 1969 abnormality needs to be 

investigated to determine if there were problems with the dosimetry system (which may have 

spilled over into other years), or if the lack of recorded positive dose was a result of other 

influences, such as changes in operations, lost records, etc.

Finding 10: It may not be always correct to assume that unmonitored workers experienced 

exposures that were generally lower than those experienced by monitored workers, because 

monitoring in the early years may not have been as thorough as would be desired. In 

addition, as discussed in previous findings, coworker categories are ambiguous and might 

result in inappropriate coworker dose assignments. Furthermore, Table 15 may reflect 

decreased average recorded doses as the number of zero dose records included may not be 

a complete accounting of the actual dose to workers. 

6.2.1 Dosimeter Response to Low-Energy Photons 

Page 24 of the site profile (ORAUT 2006) states the following: 

The photon energy spectra in KCP workplaces have not been measured. The 

spectra are related to the configuration of the X-ray machines, the process, and 

the extent of shielding. However, regardless of the precise spectra, significant 

photon radiation would have been readily measured at KCP by the available 

dosimeter technology during all years of operation. 
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And on p. 28, it is stated: 

The energy of prevalent photons based on the radiation sources is readily 

measured, so no adjustment of recorded dose would be likely based on the 

response characteristics of the different dosimeters. 

However, on p. 25, it is stated: 

Eberline standard (three-chip, TLD-100) TLD – used from 1983 through 1990. 

This dosimeter employs one chip under a 10-mg/cm2

 filter to measure the shallow 

or skin dose and one or two chips under a 285-mg/cm2

 filter to measure the deep 

or whole-body dose (TMA 1990). The use of this dosimeter was terminated due to 

its inability to pass DOELAP lower energy photon performance testing 

categories... 

The dosimeters were apparently calibrated using Co-60 (ORAUT 2006, p. 24), which is a 

relatively energetic photon source (1.17 and 1.33 MeV). However, numerous x-ray producing 

units were used at the KCP, as listed in Table 4 (ORAUT 2006, p. 12). These x-ray machines 

produced a wide spectrum of primary and scattered photons down to very low energies. The 

dosimeters calibrated using Co-60 may not have correctly responded to these lower-energy 

photons. Therefore, a correction factor may be needed, especially for determining the dose to 

skin and shallow organs. 

Finding 11: A correction factor for exposures to photon radiation might be needed, due to 

the differences between the actual photon energy distributions created largely by x-ray 

machines, and the relatively high-energy photons associated with Co-60, which was used 

for calibration of dosimeters. This issue is especially of concern regarding exposures to 

skin and shallow organs. 

6.2.2 KCP Site Profile Text Issues 

The following areas need clarification/correction to provide more definitive information for the 

reader or dose reconstructor: 

 Radiation Sources – Table 4 (p. 12.) provides a list of the typical radiation sources used 

at the KCP. The 230-curie Cesium Irradiator is listed as used for “Calibration of 

radiation detection instruments.” However, this would be a very large source to use for 

calibration of instruments; most likely it was an irradiation source for parts or inspection, 

not for calibrating instruments. 

 Neutron Dosimeters – The text in Section 6.3.2 (p. 25) discusses only the Lexan 

neutron detector, but lists other neutron detectors in Table 14. The text should provide 

information concerning all types of neutron detectors used at the KCP. Additionally, 

Table 14 is incomplete for the 1961–1967 and 1967–1973 time periods, because the type 

of neutron detector is not specified (1967–1973 only lists “film,” not specifically NTA 

film). 
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However, this report is pre-decisional and has not been reviewed by the Advisory Board on Radiation and Worker 

Health for factual accuracy or applicability within the requirements of 42 CFR 82. 

NOTICE:

 Shallow Dose Uncertainty – Section 6.5.4 (p. 31) discusses using Tables 19 and 20 for 

determining the uncertainty for shallow doses. However, Section 6.5.3 recommends an 

alternative approach for photon dose that is simpler; the KCP site profile should state 

whether this alternative approach also is applicable to shallow dose. 

 MDL Method not Applicable to Gaps in Records – The last paragraph on page 26 

reads: 

Dose reconstructors should use Method 1 if there is sufficient information 

and only occasional missed doses, and Method 2 if significant doses are 

zero or missing. Use Method 2 for workers who were monitored with 

missing or zero recorded dose or who worked in an area or an occupation 

where positive dose would be expected but was not recorded. 

The term “missing” in this content refers to the lack of entry in the dose records, or the 

lack of dose records. Therefore, assigning dose based on Method 2 (MDL of the 

detector) is scientifically incorrect, because the worker did not wear a monitor, or the 

results were not recorded. Instead, coworker or adjacent recorded doses in the worker’s 

records should be used to fill this gap. 

 Incorrect Table Reference – The last paragraph on page 33 of Section 6.6 states “...is to 

use the organ DCFs for an AP exposure geometry as indicated in Tables 6 and 7.” 

However, Tables 6 and 7 are from Section 3 for occupational medical exposures. It 

appears that this statement should refer to Tables 21 and 22 in this section.
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However, this report is pre-decisional and has not been reviewed by the Advisory Board on Radiation and Worker 

Health for factual accuracy or applicability within the requirements of 42 CFR 82. 

7.0 REFERENCES 

42 CFR 82, 2002. Methods for Radiation Dose Reconstruction under the Energy Employees 

Occupational Illness Compensation Program Act of 2000; Final Rule, Federal 

Register/Vol.67, No. 85/Thursday, May 2, 2002, p. 22314. 

DOE (U.S. Department of Energy), 1997. Linking Legacies, DOE/EM-0319, Office of 

Environmental Management, Washington, DC. 

ICRP (International Commission on Radiological Protection), 1995. Age-Dependent Doses to 

Members of the Public from Intake of Radionuclides: Part 4 Inhalation Dose Coefficients, ICRP 

Publication 71, Pergamon Press, Oxford, England. 

Nasca, B.M., 2005. Letter from B.M. Nasca to R.J. Traub, Subject: “Re: E-mail dated 2/8/05, 

Uranium Bioassay.” Dosimetry records of four individuals were attached to this letter. February 

9, 2005. SRDB ID 49002. 

NCRP (National Council on Radiation Protection and Measurements) 1996. Screening Models 

for Releases of Radionuclides to Atmosphere, Surface Water, and Ground, Report 123 I, 1-316, 

Bethesda, Maryland. 

ORAUT 2005. Dose Reconstruction from Occupationally Related Diagnostic X-ray Procedures, 

ORAUT-OTIB-0006, Rev. 03, Oak Ridge Associated Universities Team: Cincinnati, Ohio. 

December 21, 2005. 

ORAUT 2006. Site Profile for the Kansas City Plant, ORAUT-TKBS-0031, Rev. 00 PC-1, Oak 

Ridge Associated Universities Team, Cincinnati, Ohio. January 6, 2006. 

Phillips, L., 1974. Personnel Dosimetry. Brookhaven National Laboratory, Upton, New York. 

Ref ID 22429. 

SC&A 2004. Standard Operating Procedure for Performing Site Profile Review, S. Cohen and 

Associates, Vienna, Virginia. March 18, 2004. 

TMA (Thermo Analytical, Inc.) 1990. Radiation Dosimetry: TLD Service for Personnel & 

Environmental Monitoring, TMA Eberline, Albuquerque, New Mexico. 

Traub, R.T., 2005. E-mail correspondence from R.T. Traub (Battelle) to B.M. Nasca (KCP) 

regarding occupational codes. February 25, 2005. SRDB ID 15925.