Page 1 of 28

DOE Review Release 12/03/2019

Oak Ridge Gaseous Diffusion Plant (K-25) – 

Occupational Medical Dose

ORAUT-TKBS-0009-3 Rev. 02

Effective Date: 11/18/2019

Supersedes: Revision 01

Subject Expert(s): Michalene Rodriguez, Robert C. Winslow

Document Owner 

Approval: Signature on File

Michalene Rodriguez, Document Owner

Approval Date: 10/21/2019

Concurrence: Signature on File

John M. Byrne, Objective 1 Manager

Concurrence Date: 10/21/2019

Concurrence: Signature on File

Scott R. Siebert, Objective 3 Manager

Concurrence Date: 10/21/2019

Concurrence: Vickie S. Short Signature on File for

Kate Kimpan, Project Director

Concurrence Date: 10/21/2019

Approval: Signature on File

Timothy D. Taulbee, Associate Director for Science

Approval Date: 11/18/2019

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

REVISION AND DISCARD / DESTROY ALL COPIES OF THE PRIOR REVISION.

New Total Rewrite Revision Page Change
Document No. ORAUT-TKBS-0009-3 Revision No. 02 Effective Date: 11/18/2019 Page 2 of 28

PUBLICATION RECORD

EFFECTIVE

DATE

REVISION

NUMBER DESCRIPTION

06/29/2004 00 New technical basis document for the Oak Ridge Gaseous Diffusion 

(K-25) plant – Occupational Medical Dose. First approved issue. 

Initiated by Jay J. Maisler.

11/07/2006 00 PC-1 Approved page change revision to update required language on 

pages 4 and 5 in Section 3.1. Updates acronyms and abbreviations 

on page 3. Adds a Purpose Section and a Scope Section on page 5. 

No sections were deleted. No further changes occurred as a result 

of formal internal review. No changes required to this document due 

to Worker Outreach comments. This revision results in no change to 

the assigned dose and no PER is required. Training as required by 

Task Manager. Initiated by Paul A. Szalinski. Approval: 

Signature on File 10/24/2006

Paul A. Szalinski, Document Owner

Signature on File 10/20/2006

John M. Byrne, Task 3 Manager

Signature on File 10/24/2006

Edward F. Maher, Task 5 Manager

Signature on File 10/23/2006

Kate Kimpan, Project Director

Signature on File 11/07/2006

James W. Neton, Associate Director for Science

03/28/2013 01 Revision to update doses according to site-specific information and 

recently revised ORAUT-OTIB-0006. Incorporates resolutions to 

Sanford Cohen & Associates comments. Also incorporates formal 

internal and NIOSH review comments. Constitutes a total rewrite of 

the document. Training required: As determined by the Objective 

Manager. Initiated by Michalene Rodriguez.

11/18/2019 02 Revision initiated to (1) update doses to the present era, (2) provide 

directions about lumbar spine examination records, and (3) provide 

IREP dose distributions and statistical parameters for B-lymphocytes 

(Table 3-3). Incorporates formal internal and NIOSH review 

comments. Constitutes a total rewrite of the document. Training 

required: As determined by the Objective Manager. Initiated by 

Michalene Rodriguez. 
Document No. ORAUT-TKBS-0009-3 Revision No. 02 Effective Date: 11/18/2019 Page 3 of 28

TABLE OF CONTENTS

SECTION TITLE PAGE

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

3.1 Introduction ................................................................................................................................. 5

3.1.1 Purpose........................................................................................................................... 6

3.1.2 Scope.............................................................................................................................. 6

3.1.3 Special Exposure Cohort ................................................................................................ 6

3.2 Background, Examination Types, and Frequencies ................................................................... 6

3.3 Equipment and Techniques ........................................................................................................ 8

3.3.1 Chest Photofluorography (PFG), April 1945 to 1956 ...................................................... 8

3.3.1.1 Dose Reconstruction Guidance........................................................................ 9

3.3.2 Chest Radiography, October, 1944 to 1961..................................................................10

3.3.3 Chest Radiography, 1962 to 1970 ................................................................................11

3.3.4 Chest Radiography, 1971 to 1986 ................................................................................12

3.3.5 Chest Radiography, 1987 to 2000 ................................................................................12

3.3.6 Chest Radiography, 2001 to May 15, 2019...................................................................13

3.4 Organ Dose Calculations ..........................................................................................................14

3.5 Uncertainty................................................................................................................................16

3.6 Attributions and Annotations .....................................................................................................16

References ...........................................................................................................................................23

Glossary................................................................................................................................................26

LIST OF TABLES

TABLE TITLE PAGE

3-1 Assumed default frequency of screening chest X-rays at K-25 based on review of 

records and references ............................................................................................................... 8

3-2 Organ dose correction factors and other factors to calculate skin dose for PFG exams ..........10

3-3 Organ dose correction factors and other factors to calculate skin dose for 1944–1961 ...........11

3-4 Organ dose correction factors and other factors to calculate skin dose for 1962–1970 ...........12

3-5 Skin calculation factors – PA and LAT chest for 1971 to 1986 .................................................12

3-6 Skin calculation factors – PA and LAT chest for 1987 to 2000 .................................................13

3-7 Skin calculation factors – PA and LAT chest for 2001 to May 15, 2019 ...................................14

3-8 X-ray equipment and incident air kerma values........................................................................15

3-9 IREP dose distributions and statistical parameters for the dose to the B-lymphocytes ............15

3-10 Organ dose equivalent per X-ray procedure for chest X-ray examinations, 1944 to May 

15, 2019....................................................................................................................................17

3-11 Skin dose guidance and skin dose equivalents for chest projections, October 1944 

through 1970.............................................................................................................................19

3-12 Skin dose guidance and skin dose equivalents for chest projections, 1971 to May 15, 

2019..........................................................................................................................................21
Document No. ORAUT-TKBS-0009-3 Revision No. 02 Effective Date: 11/18/2019 Page 4 of 28

ACRONYMS AND ABBREVIATIONS 

AWE atomic weapons employer

cGy centigray

cm centimeter

DCF dose conversion factor

DOE U.S. Department of Energy

DOL U.S. Department of Labor

EEOICPA Energy Employees Occupational Illness Compensation Program Act of 2000

ENSD entrance skin dose

ETTP East Tennessee Technology Park

EXSD exit skin dose

GE General Electric

Gy gray

HVL half-value layer

in. inch

IREP Interactive RadioEpidemiology Program

kVp peak kilovoltage

LAT lateral

mA milliampere

mm millimeter

NIOSH National Institute for Occupational Safety and Health

ORAU Oak Ridge Associated Universities

PA posterior-anterior

PER Program Evaluation Report

PFG photofluorography

RSD remote skin dose

s second

SEC Special Exposure Cohort

SRDB Ref ID Site Research Database Reference Identification (number)

TBD Technical basis document

U.S.C. United States Code

yr year

§ section or sections
Document No. ORAUT-TKBS-0009-3 Revision No. 02 Effective Date: 11/18/2019 Page 5 of 28

3.1 INTRODUCTION

Technical basis documents and site profile documents are not official determinations made by the 

National Institute for Occupational Safety and Health (NIOSH) but are rather general working 

documents that provide historical background information and guidance to assist in the preparation of 

dose reconstructions at particular Department of Energy (DOE) or Atomic Weapons Employer (AWE) 

facilities or categories of DOE or AWE facilities. They will be revised in the event additional relevant 

information is obtained about the affected DOE or AWE facility(ies). These documents may be used 

to assist NIOSH staff in the evaluation of Special Exposure Cohort (SEC) petitions and the completion 

of the individual work required for each dose reconstruction.

In this document the word “facility” is used to refer to an area, building, or group of buildings that 

served a specific purpose at a DOE or AWE facility. It does not mean nor should it be equated to an 

“AWE facility” or a “DOE facility.” The terms AWE and DOE facility are defined in sections 7384l(5) 

and (12) of the Energy Employees Occupational Illness Compensation Program Act of 2000 

(EEOICPA), respectively. An AWE facility means “a facility, owned by an atomic weapons employer, 

that is or was used to process or produce, for use by the United States, material that emitted radiation 

and was used in the production of an atomic weapon, excluding uranium mining or milling.” 42 U.S.C. 

§ 7384l(5). On the other hand, a DOE facility is defined as “any building, structure, or premise, 

including the grounds upon which such building, structure, or premise is located ... in which 

operations are, or have been, conducted by, or on behalf of, the [DOE] (except for buildings, 

structures, premises, grounds, or operations ... pertaining to the Naval Nuclear Propulsion Program);” 

and with regard to which DOE has or had a proprietary interest, or “entered into a contract with an 

entity to provide management and operation, management and integration, environmental 

remediation services, construction, or maintenance services.” 42 U.S.C. § 7384l(12). The Department 

of Energy (DOE) determines whether a site meets the statutory definition of an AWE facility and the 

Department of Labor (DOL) determines if a site is a DOE facility and, if it is, designates it as such.

Accordingly, a Part B claim for benefits must be based on an energy employee’s eligible employment 

and occupational radiation exposure at a DOE or AWE facility during the facility’s designated time

period and location (i.e., covered employee). After DOL determines that a claim meets the eligibility 

requirements under EEOICPA, DOL transmits the claim to NIOSH for a dose reconstruction. 

EEOICPA provides, among other things, guidance on eligible employment and the types of radiation 

exposure to be included in an individual dose reconstruction. Under EEOICPA, eligible employment 

at a DOE facility includes individuals who are or were employed by DOE and its predecessor 

agencies, as well as their contractors and subcontractors at the facility. Unlike the abovementioned 

statutory provisions on DOE facility definitions that contain specific descriptions or exclusions on 

facility designation, the statutory provision governing types of exposure to be included in dose 

reconstructions for DOE covered employees only requires that such exposures be incurred in the 

performance of duty. As such, NIOSH broadly construes radiation exposures incurred in the 

performance of duty to include all radiation exposures received as a condition of employment at 

covered DOE facilities in its dose reconstructions for covered employees. For covered employees at 

DOE facilities, individual dose reconstructions may also include radiation exposures related to the 

Naval Nuclear Propulsion Program at DOE facilities, if applicable. No efforts are made to determine 

the eligibility of any fraction of total measured exposure for inclusion in dose reconstruction.

NIOSH does not consider the following types of exposure as those incurred in the performance of 

duty as a condition of employment at a DOE facility. Therefore these exposures are not included in 

dose reconstructions for covered employees (NIOSH 2010):

• Background radiation, including radiation from naturally occurring radon present in 

conventional structures

• Radiation from X-rays received in the diagnosis of injuries or illnesses or for therapeutic 

reasons
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3.1.1 Purpose

This technical basis document (TBD) details historical practices and provides the basis for organ dose 

from medical X-ray procedures for occupational health screening at K-25.

Over the years, the Oak Ridge Gaseous Diffusion Plant has been known as the K-25 Plant, the Oak 

Ridge K-25 Site, and now the East Tennessee Technology Park (ETTP). For convenience, this 

document uses K-25 for earlier years and ETTP for later years. 

3.1.2 Scope

The K-25 occupational health and safety program required pre-employment, periodic physical, and 

termination health monitoring examinations from the beginning of its operation in 1944 (Author 

unknown 1946, p. 94; Author unknown 1947, p. 2). These examinations typically included chest

X-rays. The doses from these procedures depended on the characteristics of the X-ray machine and 

the techniques used. Site-specific information about the K-25 X-ray screening program is used to the 

extent it is known.

3.1.3 Special Exposure Cohort

This document provides supporting technical data to assist in the reconstruction of occupational 

medical doses. K-25 is one of the original sites that was designated by Congress as part of the 

Special Exposure Cohort (SEC) under EEOICPA [42 U.S.C. § 7384l(14)]. This designation is as 

follows:

(A) The employee was so employed for a number of work days aggregating at least 250 

work days before February 1, 1992, at a gaseous diffusion plant located in Paducah, 

Kentucky, Portsmouth, Ohio, or Oak Ridge, Tennessee, and, during such employment— 

(i) was monitored through the use of dosimetry badges for exposure at the plant of 

the external parts of employee’s body to radiation; or

(ii) worked in a job that had exposures comparable to a job that is or was monitored 

through the use of dosimetry badges. 

Dose reconstruction guidance in this document is presented to provide a technical basis for dose 

reconstructions for nonpresumptive cancers that are not covered in the SEC class through 

January 31, 1992. Dose reconstructions for individuals who were employed at K-25 before 

February 1, 1992, but who do not qualify for inclusion in the SEC, can be performed using this 

guidance.

3.2 BACKGROUND, EXAMINATION TYPES, AND FREQUENCIES

Before the K-25 Medical Dispensary was operational, the workers had their pre-employment 

examinations at the Medical Services Building of the Oak Ridge Hospital (Author unknown 1946, 

p. 88). Built by the Army Corps of Engineers, the Oak Ridge Hospital opened their doors on 

November 17, 1943 (Brookshire and Wallace 2009). Little is known about the X-ray machines at the 

Oak Ridge Hospital, but the dose from pre-employment chest X-rays taken there should be included 

in dose reconstruction because it is a covered facility (DOE 2019). Unless otherwise noted, dose 

reconstructors should assume X-rays were taken at the Oak Ridge Hospital from November 17, 1943 

through September, 1944. Before the opening of the Oak Ridge Hospital, no dose from occupational 

X-rays should be assigned.
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The Carbide and Carbon Chemicals Corporation organized a medical department at K-25 in April, 

1944 (Author unknown 1946, p. 88). Pre-employment examinations were conducted in the Carbide 

and Carbon Administration Building from April, 1944 to July, 1944 (Author unknown 1946, pp. 87, 88). 

It is doubtful that this building had X-ray capabilities, and it is assumed workers were sent to the Oak 

Ridge Hospital for X-rays during this time. 

The medical department at the main dispensary began operating in July, 1944. Due to the rise in the 

number of X-ray procedures required for diagnostic purposes, X-ray equipment was installed at the 

dispensary and available beginning October, 1944, and a photoroentgen unit was later added in April, 

1945 (Author unknown 1946, p. 89). Workers from the Ford, Bacon, and Davis Company and the H. 

K. Ferguson Company (Fercleve Corporation), both contractors, were also examined at the K-25 

dispensary (Author unknown 1946, p. 89).

During the early years at K-25, when little was known about health effects of working with uranium, 

X-ray examinations were performed frequently in an effort to monitor worker health, perhaps as often 

as every 6 months (Kammer 1948, p. 8). During recheck examinations, individuals in special hazard 

groups may have received an X-ray examination (Author unknown 1947). In addition, it was noted 

that X-rays were performed on individuals who received a major acute exposure from uranium (Author 

unknown 1947). Bocher (1948) writes that workers handling process material might be X-rayed 

excessively. 

Table 3-1 lists the nominal frequency of examinations over the years during which X-rays were 

required as part of occupational health screening. Some workers might have received these X-rays 

on a schedule different from that listed in Table 3-1. Dose reconstructors should assign dose 

according to the X-rays performed for screening listed in the claim file records, and in the absence of 

records, according to the frequency listed in Table 3-1. 

K-25 workers who subsequently worked at Y-12 or X-10 might have had their X-ray records 

transferred to the Y-12 or X-10 medical departments. Because X-ray records are not typically 

submitted by Y-12 or X-10 during the initial request, the dose reconstructions of these workers should 

be completed by (1) assuming the X-ray frequency from Table 3-1 for their K-25 employment, or 

(2) submitting a repeat request for the X-ray records from Y-12 or X-10. An additional request for Xray records would only be necessary when the claim is in the best-estimate range.

Other X-rays (i.e., pelvis, lumbar spine, thoracic and cervical spine exams) may have been performed 

for workers with the potential for exposure to fluoride or fluoride compounds (ORAUT-OTIB-0006

2019, p. 33). Historical evidence of a routine fluorosis screening program at K-25 has not been found. 

In fact, Cardarelli (2000, p. 82) revealed from a study that was conducted of 297 employee medical 

records, ranging in date from 1944 through 1989, a total of 2,188 X-ray records were evaluated; of the 

2,188 records, only 50 were lumbar spine X-rays (2.28%) and 7 were pelvic exams (0.32%). Due to 

the low number of lumbar spine and pelvic exams from this study, it appears a fluorosis screening 

program at K-25 probably did not exist. 

These additional radiographic examinations may have been nonoccupational; in the sense that they 

were necessitated by illness or injury and were not part of the employee occupational health 

screening process. For example, a review of some claim file records reveal lumbar spine X-rays can 

be traced to occurrence of injury, complaints, or symptoms of back pain in the respective workers’ 

records, and therefore do not meet the definition of X-ray screening (Thomas 2015). Thus, if lumbar 

spine, pelvic, thoracic and cervical spine exams are present in the employee’s records, they are not to 

be used for dose reconstruction purposes.
Document No. ORAUT-TKBS-0009-3 Revision No. 02 Effective Date: 11/18/2019 Page 8 of 28

Table 3-1. Assumed default frequency of screening chest X-rays at K-25 based on review of records 

and references. 

Period Frequency Employee Type

Before 

November 17, 1943

None None None

November 17, 1943–

September, 1944

Preemploymenta All employees PFG 

October, 1944–1956 Preemployment,b annual,

c

and terminationb,c

All employeesb See Section 3.3.1.1

1957–1961b Preemployment,d annual,

d

and terminationd

All employees PA chest

1962–1970 Preemployment, every 1–2 yr, 

and termination

Radiation workers 

>40 years old d,e

PA chest

1962–1970 Preemployment, every 2+ yr, 

and termination

Radiation workers 

<40 years oldd,e

PA chest

1971–1986 Preemployment, every 1–2 yr, 

and termination

Radiation workers

>40 years olde,f

PA and lateral (LAT)

chest

1971–1986 Preemployment, every 2+ yr, 

and termination

Radiation workers 

<40 years olde,f

PA and LAT chest

1987–2000 Preemployment, annual, and 

termination

Radiation workersg PA and LAT chest

2001–May 15, 2019 Preemployment, some periodic 

depending on hazard group, 

some terminationh,i

Some X-rays might have been 

taken at a noncovered facility.

Workers in surveillance 

programs (e.g., 

HAZWOPER, asbestos, 

respirator).

PA and LAT chest

May 16, 2019–

present

None – all X-rays taken at a 

noncovered facility.

j 

None None

a. X-rays taken at the Oak Ridge Hospital

b. Source: Author unknown (1947, p. 2).

c. Semiannually for workers with potential for exposure to uranium dust (Kammer 1948). 

d. Source: UCNC (1957, p.11).

e. Source: Author unknown (1964, p. 6).

f. Source: Collins (1988).

g. Source: DOE (1993, p. 95-97).

h. Source: Prater (2015a, p. 3).

i. Source: Prater (2015b, p. 3).

j. Source: Newman (2019).

3.3 EQUIPMENT AND TECHNIQUES

The type of X-ray equipment used at K-25 from the inception of the Medical Dispensary from 1944 

through May 15, 2019, is provided below in Section 3.3.1 through Section 3.3.6. 

3.3.1 Chest Photofluorography (PFG), April 1945 to 1956

PFG had widespread use throughout the United States for tuberculosis screening in the 1930s and 

was state-of-the-art medical technology when work began at the K-25 plant as part of the Manhattan 

Project. Eventually, PFG was phased out in favor of the conventional chest X-ray examination using 

14- × 17-in. film.

Before the opening of the K-25 Medical Dispensary the examinations were performed at the Oak 

Ridge Hospital in Oak Ridge, Tennessee. It is known that the Oak Ridge Hospital had a PFG 

machine (Gupton et al. 1957, p. 21). It is therefore possible that the preplacement medical X-rays 

taken at the Oak Ridge Hospital could have been PFG. Unless otherwise noted, preplacement X-rays 

performed at the Oak Ridge Hospital should be considered stereo PFG and the dose values obtained 
Document No. ORAUT-TKBS-0009-3 Revision No. 02 Effective Date: 11/18/2019 Page 9 of 28

from ORAUT-OTIB-0006, Dose Reconstruction from Occupational Medical X-Ray Procedures

(ORAUT 2019). 

A PFG machine was added to the K-25 medical dispensary in April 1945 (Author unknown 1946, p. 

89). A stereo PFG was “taken on every person hired by the companies served by the Dispensary” 

(Author unknown 1947, p. 12). Lyon (1949, p. 7) writes that both the pre-employment and the annual 

examination were made on the PFG unit at K-25, with “all other chest X-rays” made on a 14- × 17-in.

film.

The PFG machine at K-25 was a General Electric (GE) Photoroentgen X-ray machine (Author 

unknown 1947, p. 12) that was used with a grid to produce miniature 4- × 5-in. stereoscopic posterioranterior (PA) chest X-rays (Cardarelli 2000). The stereoscopic technique produces two images of the 

chest (on 4- × 10-in. film) at slightly different angles, resulting in a three-dimensional image of the 

chest when viewed through a stereoscope (Laughlin et al. 1957). While two references refer to PFG 

at K-25 on either 4- × 5-in. or 4- × 10-in. film (Cardarelli 2000, and Author unknown 1949, p. 12), the 

K-25 claim file records indicate some PFG on 70 mm film, another common film type for PFG images 

(Laughlin et al. 1957).

A survey performed on the machines at K-25 listed the technique factors for PFG as 68 kVp, 200 mA, 

and 0.75 s with a skin dose rate of 6.4 R (Gupton et al. 1957, p. 22). It is assumed that this technique 

is for stereo projection based on the notation that appears to indicate the time was applied twice. The 

survey does not include half-value layer (HVL) or total filtration information, so a HVL of 2.5 mm Al at 

68 kVp is assumed for dose reconstruction. Based on the information provided, this dose was 

determined to be a free in air dose and was converted to incident air kerma using Equation 4-1 of 

ORAUT-OTIB-0006 (ORAUT 2019). This results in an incident air kerma of 5.61 cGy for stereo PFG.

The DCFs applied to calculate organ dose are provided in ORAUT-OTIB-0006, Table B-2 (ORAUT 

2019) with the exception of those provided below in Table 3-2. Table 3-2 also provides the factors 

from Tables B-7 and B-8 of NCRP Report 102 (NCRP 1989) used to calculate skin dose for PFG 

procedures. The DCFs used for organ dose calculation for the ovaries, testes and uterus are the 

DCFs for the respective organs for a PA Abdominal projection from ICRP Publication 34 (1982). The 

DCFs for the urinary bladder/prostate and colon/rectum are based on using the ovaries as a surrogate 

organ and therefore, also uses the DCF for ovaries for a PA abdominal projection. The use of the 

abdominal DCFs for these organs accounts for poor collimation of X-ray beams during this timeframe. 

Note: this is a difference from OTIB-0006 default which uses measured doses for these organs for 

PFG.

As noted above, the film size for the PFG is 4- × 5-in (10.16 cm × 12.7 cm) which must be taken into 

account when determining the Back Scatter Factor and Average Percentage Depth Doses. Table B-8 

of NCRP Report 102 (NCRP 1989) provides these factors for the following field sizes in cm: 0, 15 ×

15, and 35 × 35. Interpolation between the 0 field and 15 × 15 cm field and taking into account the 

2.5 mm HVL, results in a BSF of 1.18 and ADD of 6.9 as indicated below.

3.3.1.1 Dose Reconstruction Guidance

Before 1957, the exam type is often unclear in records provided by the DOE. For instance the phrase 

“P.A. view of the chest” is recorded frequently, but this can imply either a conventional 14- × 17-in. or 

a stereoscopic PA PFG X-ray. In a past study, films located in the film jackets for several workers 

with employment before 1957 were measured. The results reveal that approximately 77% of the 

X-ray exams were 4- × 10-in. PFG examinations. Because the difference in size affects assigned 

dose, NIOSH has asked K-25 to clarify whether “P.A. view of the chest” means a 4- × 10-in. film 

(PFG) or a 14- × 17-in. film by actually looking into the film jackets of claimants and documenting the 

X-ray type before submitting the records to NIOSH (Nelson 2014).
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Table 3-2. Organ dose correction factors and other factors to calculate skin dose for PFG exams. 

Organ/factor DCF/skin calculation factors

Ovariesa 1.68E–01

Urinary bladder/prostateb 1.68E–01

Colon/rectumb 1.68E–01

Testesc 9.10E–03

Uterusd 1.49E–01

Back Scatter Factor (BSF)e 1.18

Absorption Factor (AF)f 50.95

Average Percentage Depth Doses (ADD)g 6.9

a. Ovaries DCF for PA Abdominal used to account for poor collimation.

b. Ovaries DCF for PA Abdominal as surrogate to account for poor collimation.

c. Testes DCF for PA Abdominal used to account for poor collimation.

d. Uterus DCF for PA Abdominal used to account for poor collimation. 

e. BSF from NCRP 102, Table B.8, based on 2.5 mm HVL and 10.16 cm X 12.7 cm field size. 

f. AF from NCRP 102, Table B.7, based on 2.5 mm HVL, 24 cm Tissue Thickness for PA.

g. ADD from NCRP 102, Table B.8, based on 2.5 mm HVL, 10.16 cm X 12.7 cm field size, and 12 cm depth for PA. 

For that reason, between October, 1944 and December, 1956, dose reconstructors should follow the 

guidance below.

X-ray records absent

*Assume PFG and frequency listed in Table 3-1. 

X-ray records provided

*Notation on X-ray record should indicate the size of the film, i.e. 4- x 5-in, 4- x 10-in., 14- x 17-in or 

70 mm. Film size/type should indicate whether PFG exam or the conventional 14- x 17-in. film was 

performed.

X-ray records provided, but size of film not noted

*Assume all “PA Chest X-rays are PFG exams when the POC is <45%.

*If the POC is > or equal to 45%, then make a request to the site that the film size be assessed for 

accurate identification for each chest X-ray prior to 1957.

There is no evidence of PFGs performed at K-25 after 1956 from a review of claim file records, which 

corroborates other information on K-25 (Cardarelli 2000; Cardarelli et al. 2002). The organ doses 

listed in Table 3-10 and Table 3-11 are based on the assumption of stereo PFG.

3.3.2 Chest Radiography, October, 1944 to 1961

A Westinghouse machine was used to produce 14- × 17-in. chest radiographs (Author unknown 1947, 

p. 12). The radiographs were used to investigate suspicious areas on PFG images, so it is possible 

that some employees had both PFG and conventional chest X-rays from 1944 to 1956. After 1956, 

only conventional PA chest radiographs were taken, which substantially reduced radiation dose per 

examination.

The 1957 survey (Gupton et al. 1957, p. 22) provides technique factors and dose rates for 

conventional PA chest radiographs on 14- × 17-in. for the Westinghouse machine at K-25. According 

to the survey, PA chests were performed at 65 kVp, 200 mA, and 0.1 s with a skin dose of 55 mR. 

Based on the information provided, this dose rate was determined to be a free in air dose and was 

converted to incident air kerma using Equation 4-1 of ORAUT-OTIB-0006 (ORAUT 2019). This 

results in an incident air kerma of 4.82E–02 cGy. The survey does not include HVL or total filtration 

information, so an HVL of 2.0 mm Al at 65 kVp is assumed for dose reconstruction.
Document No. ORAUT-TKBS-0009-3 Revision No. 02 Effective Date: 11/18/2019 Page 11 of 28

The DCFs applied to calculate organ dose are provided in Table 3-3 below. The DCFs have been 

selected based on the 2.0 mm HVL and based on the assumption poor collimation was used when Xrays were performed during this time period. The table also provides the factors from Tables B-7 and 

B-8 of NCRP Report 102 (NCRP 1989) used to calculate skin dose. The organ doses for this time 

period are listed in Table 3-10 and Table 3-11.

Table 3-3. Organ dose correction factors and other factors to calculate skin dose for 1944–1961. 

Organ/factor DCF/skin calculation factors

Thyroid 1.51E–01

Eye/brain 2.10E–02

Ovariesa 1.15E–01

Urinary bladder/ prostate 1.15E–01

Colon/rectum 1.15E–01

Testesb 5.70E–03

Lung (male) 3.35E–01

Lung (female) 3.55E–01

Liver/gall bladder/spleen/ pancreas 3.55E–01

Thymus 3.55E–01

Esophagus 3.55E–01

Stomach 3.55E–01

Bone Surface 3.55E–01

Remainder 3.55E–01

Breast 3.20E–02

Uterusc 1.03E–01

Bone marrow (male) 6.90E–02

Bone marrow (female) 6.30E–02

Back Scatter Factor (BSF)

d 1.32

Absorption Factor (AF)

e 58.3

Average Percentage Depth Doses (ADD)

f 12.2

a. Ovaries DCF for PA Abdominal used to account for poor collimation.

b. Testes DCF for PA Abdominal used to account for poor collimation.

c. Uterus DCF for PA Abdominal used to account for poor collimation.

d. BSF from NCRP 102, Table B.8, based on 2.0 mm HVL and 35 × 35 cm field size.

e. AF from NCRP 102, Table B.7, based on 2.0 mm HVL, 24 cm Tissue Thickness for PA.

f. ADD from NCRP 102, Table B.8, based on 2.0 mm HVL, 35 × 35 cm field size, and 12 cm depth for PA.

3.3.3 Chest Radiography, 1962 to 1970

A Westinghouse 300-mA machine replaced the 200-mA machine in 1962 (Cardarelli 2000; Cardarelli 

et al. 2002). No information on either technique factors or beam measurements has been found for 

the Westinghouse machine presumably installed in 1962. Therefore, the incident air kerma comes 

from Cardarelli (2000) for this period. As recommended in ORAUT-OTIB-0006 (ORAUT 2019), poor 

collimation is assumed for this period. The DCFs used in calculating the dose equivalents from chest 

X-rays are listed in ORAUT-OTIB-0006 (ORAUT 2019), Table B-2, with the exception of those listed 

below in Table 3-4. 

The DCFs have been selected based on the 2.5 mm HVL. The table also provides the factors from

Tables B-7 and B-8 of NCRP Report 102 (NCRP 1989) used to calculate skin dose. Organ dose 

information is provided in Table 3-10 and Table 3-11.
Document No. ORAUT-TKBS-0009-3 Revision No. 02 Effective Date: 11/18/2019 Page 12 of 28

Table 3-4. Organ dose correction factors and other factors to calculate skin dose for 1962–1970. 

Organ/factor DCF/other factors

Ovariesa 1.68E–01

Urinary bladder/prostate 1.68E–01

Colon/rectum 1.68E–01

Testesb 9.10E–03

Uterusc 1.49E–01

Back Scatter Factor (BSF)d 1.35

Absorption Factor (AF)e 50.95

Average Percentage Depth Doses (ADD)f 14.1

a. Ovaries DCF for PA Abdominal used to account for poor collimation.

b. Testes DCF for PA Abdominal used to account for poor collimation.

c. Uterus DCF for PA Abdominal used to account for poor collimation.

d. BSF from NCRP 102, Table B.8, based on 2.5 mm HVL and 35 × 35 cm field size.

e. AF from NCRP 102, Table B.7, based on 2.5 mm HVL, 24 cm Tissue Thickness for PA.

f. ADD from NCRP 102, Table B.8, based on 2.5 mm HVL, 35 × 35 cm field size, and 12 cm depth for PA. 

3.3.4 Chest Radiography, 1971 to 1986

In the early 1970s, a lateral (LAT) chest projection was added to the chest X-ray examination 

procedure (Cardarelli 2000). The claim file records do not always indicate the LAT chest projection, 

but there is a change in the notation for the mid- to late 1970s from “PA chest” to “Chest,” which 

presumably included two projections (PA and LAT). Dose reconstructors should assign dose from 

both a PA and LAT chest for this period according to the dose values provided in Table 3-10 and 

Table 3-12. 

The X-ray machine used in this period is presumed to be the same as that for 1962 to 1970, the 

Westinghouse machine. However, because no information from this machine has been found, the 

incident air kerma comes from Cardarelli (2000) for this period. As recommended in ORAUT-OTIB0006 (ORAUT 2019), good collimation is assumed for this period.

The DCFs applied to calculate organ dose is provided in ORAUT-OTIB-0006 (ORAUT 2019) in Table

B-3 for the PA and LAT chest, after 1985, based on this period having proper collimation of the X-ray 

beam and a HVL of 4 mm. Table 3-5 provides the factors from Tables B-7 and B-8 of NCRP Report 

102 (NCRP 1989) used to calculate skin dose for chest X-ray procedures.

Table 3-5. Skin calculation factors – PA and LAT chest for 1971 to 1986. 

Factor PA LAT

Back Scatter Factor (BSF)a 1.42 1.42

Absorption Factor (AF)b 32.66 148.4

Average Percentage Depth Doses 

(ADD)c

19.3 9.325

a. BSF from NCRP 102, Table B.8, based on 4.0 mm HVL and 35 × 35 cm field size.

b. AF from NCRP 102, Table B.7, based on 4.0 mm HVL, 24 cm Tissue Thickness for PA and 34 cm Tissue Thickness for 

LAT.

c. ADD from NCRP 102, Table B.8, based on 4.0 mm HVL, 35 × 35 cm field size, 12 cm depth for PA and 17 cm depth for 

LAT. 

3.3.5 Chest Radiography, 1987 to 2000

In 1988, the Food and Drug Administration performed a survey of the Bennett general-purpose X-ray 

machine that had been installed “recently” at K-25 (Collins 1988). While the exact date of installation 

is not known, Cardarelli (2000) and Cardarelli et al. (2002) state that a new machine was installed in 

1987. They mention the Bennett machine, but also mention a Westinghouse machine in several 

places. It is assumed that a Bennett machine was installed, not a Westinghouse machine. The 

significance for dose reconstruction is that the Bennett machines used high-frequency generators in 
Document No. ORAUT-TKBS-0009-3 Revision No. 02 Effective Date: 11/18/2019 Page 13 of 28

their designs. However, no other specific information is available about the Bennett machine or the 

technique factors used, so the incident air kerma comes from Cardarelli (2000) for this period. During 

this period, environmental restoration workers were part of the medical surveillance program, which 

included a PA and LAT chest X-ray for pre-employment, annual, and termination exams (DOE 1993). 

Dose values for this period are listed in Table 3-10 and Table 3-12. 

The DCFs applied to calculate organ dose is provided in ORAUT-OTIB-0006 (ORAUT 2019) in Table

B-3 for the PA and LAT chest for 1986 and later based on this period having proper collimation of the 

X-ray beam and a HVL of 4 mm. Table 3-6 provides the factors from Tables B-7 and B-8 of NCRP 

Report 102 (NCRP 1989) used to calculate skin dose for chest X-ray procedures.

Table 3-6. Skin calculation factors – PA and LAT chest for 1987 to 2000. 

Factor PA LAT

Back Scatter Factor (BSF)a 1.42 1.42

Absorption Factor (AF)b 32.66 148.4

Average Percentage Depth Doses (ADD)c 19.3 9.325

a. BSF from NCRP 102, Table B.8, based on 4.0 mm HVL and 35 × 35 cm field size.

b. AF from NCRP 102, Table B.7, based on 4.0 mm HVL, 24 cm Tissue Thickness for PA and 34 cm Tissue Thickness for 

LAT.

c. ADD from NCRP 102, Table B.8, based on 4.0 mm HVL, 35 × 35 cm field size, 12 cm depth for PA and 17 cm depth for 

LAT. 

3.3.6 Chest Radiography, 2001 to May 15, 2019

During this period, pre-employment chest X-rays are required for workers on surveillance programs 

(e.g., HAZWOPER, asbestos, mercury, cadmium, respirator) (Prater 2015a, p. 3). The periodic exam 

frequency is variable depending on requirements for the workers in various surveillance programs and 

physician discretion. Termination physicals may have been offered, and may include X-rays. The 

chest X-rays were two projection exams, consisting of the PA and LAT chest.

X-ray procedures during this period might have been conducted at noncovered facilities such as the 

Methodist Medical Center HealthWorks (Prater 2015a, p. 3). According to K-25, when contractors 

hired large number of employees or the Medical Clinic at ETTP was overloaded, the Methodist 

Medical Center HealthWorks was used. Accordingly, new hire employees received their X-rays at the 

Methodist Medical Center HealthWorks during the following periods (Prater 2015a, p. 3):

• 2005 September through October. 

• 2006 July through December. 

• 2007 January through July; September through November. 

• 2008 March through November. 

• 2009 February through October. 

• 2010 March through April. 

• 2014 July and October. 

ETTP provided medical services (including X-rays) for some of its subcontractors that entered into 

contracts with URS/CH2M Oak Ridge (UCOR), the current sitewide operating contractor, for these 

services. ETTP provided a list of these subcontractors; however, it is expected that these 

arrangements change over time. ETTP has stated that it provides subcontractor X-ray records as part 

of its responses to NIOSH EEOICPA requests (Connell 2015, pp. 4-5). As a result, dose 

reconstructors should still follow the guidance in this document that they should assign dose (provided 

in Table 3-10 and Table 3-12) according to the X-rays performed for screening listed in the claim file 

records, and in the absence of records, according to the frequency listed in Table 3-1. The exception 

to this rule would be workers employed by British Nuclear Fuels Limited (BNFL) between 1997 
Document No. ORAUT-TKBS-0009-3 Revision No. 02 Effective Date: 11/18/2019 Page 14 of 28

through 2004. BNFL employees received their physicals and X-ray exams at an occupational health 

clinic in Oak Ridge (a noncovered facility) (ORAUT 2014a; ORAUT 2017). 

The DCFs applied to calculate organ dose is provided in ORAUT-OTIB-0006 (ORAUT 2019) in Table

B-3 for the PA and LAT chest 1986 and later based on this period having proper collimation of the Xray beam and an HVL of 4 mm. Table 3-7 provides the factors from Tables B-7 and B-8 of NCRP 

Report 102 (NCRP 1989) used to calculate skin dose for chest X-ray procedures.

Table 3-7. Skin calculation factors – PA and LAT chest for 2001 to May 15, 2019. 

Factor PA LAT

Back Scatter Factor (BSF)a 1.42 1.42

Absorption Factor (AF)b 32.66 148.4

Average Percentage Depth Doses (ADD)c 19.3 9.325

a. BSF from NCRP 102, Table B.8, based on 4.0 mm HVL and 35 × 35 cm field size.

b. AF from NCRP 102, Table B.7, based on 4.0 mm HVL, 24 cm Tissue Thickness for PA and 34 cm Tissue Thickness for 

LAT.

c. ADD from NCRP 102, Table B.8, based on 4.0 mm HVL, 35 × 35 cm field size, 12 cm depth for PA and 17 cm depth for 

LAT. 

Any records from Methodist Medical Center HealthWorks or other noncovered facility should not be 

included in the dose assessment because they would be considered offsite facilities (ORAUT 2017). 

Due to the downsizing of ETTP, the ETTP Medical Department was relocated to an area in the City of 

Oak Ridge by the close of business on May 20, 2019. The X-ray equipment was last used on May 15, 

2019, and remained in Building K-1007; but was deemed inoperable (Newman 2019). After May 15, 

2019, all X-rays are to be performed at the Methodist Medical Center in Oak Ridge (Newman 2019). 

Again, because this is a noncovered facility, these exams should not be included in the dose 

reconstruction process.

It appears that the same Bennett machine was used from 2001 through May, 2019 (Prater 2015a, 

p. 3). The reported technique factors for 2008 are 90 kVp and 5 mAs for the PA chest, and 100 kVp 

13 mAs for the LAT chest (Osborne 2015, p. 50). Measurements and calculation of the HVL and 

entrance skin exposure are available for 2000 to 2008. The measured HVL was 4.0 mm Al for the PA 

chest. The measurements provided were based on various torso thickness. For the PA chest a 

thickness of 23 cm, 25 cm, 27 cm and 30 cm reading are provided. For the LAT, a thickness of 36 cm 

39 cm and 42 cm dose readings are provided. For the PA chest, interpolation between the average

readings for 23 cm readings and the 25 cm was used to reflect the 24 cm torso assumption. For the 

LAT, the 36 cm average from 2000 to 2008 was used. The incident air kerma for the PA and LAT 

chests, respectively, and converted to incident air kerma as described in ORAUT-OTIB-0006 (ORAUT 

2019), Equation 7-1. Manual technique factors were used up to August 27, 2009, when a phototimer 

was installed for phototimed exposures. The manual technique factors described are assumed from 

the period 2001 to 2019. These data are listed in Table 3-8. 

3.4 ORGAN DOSE CALCULATIONS

Organ doses for PFG, PA, and LAT chest X-rays were based on the method described in ORAUTOTIB-0006 (ORAUT 2019) and dose conversion factors (DCFs) in ICRP Publication 34 (1982). ICRP 

(1982) provides tables of average absorbed dose (in milligrays) in selected organs for selected X-ray 

projections at 1-Gy entrance kerma (i.e., air kerma without backscatter) for selected projections and 

selected beam qualities (i.e., various HVLs). These tables list the basic DCFs for converting air 

kerma to organ dose. 
Document No. ORAUT-TKBS-0009-3 Revision No. 02 Effective Date: 11/18/2019 Page 15 of 28

Table 3-8. X-ray equipment and incident air kerma values. 

Period X-ray machine

kVp

(kV)

Assumed 

HVL

(mm Al) Image size

PA chest 

incident air 

kerma (cGy)

LAT chest 

incident air 

kerma (cGy)

April, 1945–

1956

GE (PFG) 68a 2.5 4 × 5 in.

or 70 mm

5.61a Not applicable

October, 

1944–1961

Westinghouse 200-mA 65a 2.0 14 × 17 in. 0.0482b Not applicable

1962–1970 Westinghouse 300-mA Not 

applicable

2.5c 14 × 17 in. 0.0260c Not applicable

1971–1986 Westinghouse 300-mA Not 

applicable

4.0c 14 × 17 in. 0.010c 0.030c

1987–2000 Bennett Not 

applicable

4.0c 14 × 17 in. 0.022c 0.035c

2001–

May 15, 

2019

Bennett 90/100d 4.0d 14 × 17 in. 0.006e 0.020e

a. Source: Gupton et al. (1957, p.22). The incident air kerma provided is for stereo PFG views.

b. Incident air kerma was determined using NCRP (1989) Table B-3, average air kerma rates, and corrected to the SSD 

assumed per OTIB-0006, Table 3-1.

c. Source: Cardarelli (2000, p.86). 

d. Source: Osborne (2015, pp. 50, 56, 62, 69, 76, 83, 89, 95, 101). Average of HVLs from 2000 to 2008. 

e Source: Osborne (2015, pp. 50, 56, 62, 69, 76, 83, 89, 95, 101). Average of measured values from 2000 to 2008.

Substitute DCFs for organs that are listed in the Interactive RadioEpidemiological Program (IREP) but 

without unique DCFs in ICRP Publication 34 (1982) were selected as described in ORAUT-OTIB0006 (ORAUT 2019) or are footnoted in the organ dose tables. Incident air kerma was obtained from 

Table 3-8. 

The tissue at risk for chronic lymphocytic leukemia is the B-lymphocytes. The dose to the 

B-lymphocytes was determined using the method in ORAUT-RPRT-0064, Medical Dose to the 

B-Lymphocytes (ORAUT 2014b), site-specific information, and ICRP Publication 34 DCFs (ICRP 

1982). Table 3-9 provides dose distributions and statistical parameters for input into IREP for 

determining dose to the B-lymphocytes.

Table 3-9. IREP dose distributions and statistical parameters for the dose to the B-lymphocytes.a

Projection and period

IREP 

distribution Parameter 1 Parameter 2 Parameter 3

Stereo PFG 1945–1956 Weibull3 2.886863 1.546264 0.014839 

PA chest 1944–1961 Weibull3 2.83221 0.010106 7.18521E–06 

PA chest 1962–1970 Weibull3 2.917501 0.007230 1.46275E–05

PA chest 1971–1986 Weibull3 2.096637 0.002936 2.06219E–05

LAT chest 1971–1986 Weibull3 2.109742 0.004551 3.26222E–05

PA chest 1987–2000 Weibull3 2.107841 0.006496 1.31169E–05

LAT chest 1987–2000 Weibull3 2.107070 0.005318 2.57348E–05

PA chest 2001–May 2019 Weibull3 2.093713 0.001736 1.60106E–05 

LAT chest 2001–May 2019 Weibull3 2.112819 0.003059 1.29533E–06 

a. From Chalmers (2019). 

Table 3-10 lists the organ doses for all periods. Skin doses for all skin areas were determined 

according to the method described in ORAUT-OTIB-0006 (ORAUT 2019) and listed in Tables 3-11

and 3-12. 
Document No. ORAUT-TKBS-0009-3 Revision No. 02 Effective Date: 11/18/2019 Page 16 of 28

3.5 UNCERTAINTY

It is assumed that K-25 followed the recommended standard practices implemented at other medical 

facilities. Therefore, the sources of uncertainty are assumed to be the same as the default given in 

ORAUT-OTIB-0006 (ORAUT 2019). Dose reconstructors should input the organ dose equivalent as 

the mean of a normal distribution with a standard deviation of ±30%.

3.6 ATTRIBUTIONS AND ANNOTATIONS

All information requiring identification was addressed via references integrated into the reference 

section of this document.
Document No. ORAUT-TKBS-0009-3 Revision No. 02 Effective Date: 11/18/2019 Page 17 of 28

Table 3-10. Organ dose equivalenta per X-ray procedure for chest X-ray examinations, 1944 to May 15, 2019. 

Organ Projection

April 1945–1956

GE; PFG 

(rem)

October 1944–1961

Westinghouse 

14 × 17 in.

(rem)

1962–1970

Westinghouse 

14 × 17 in.

rem)

1971–1986

Westinghouse 

14 × 17 in.

(rem)

1987–2000

Bennett

14 × 17 in.

(rem)

2001–May 2019 

Bennett 

14 × 17 in.

(rem)

Thyroid PA 9.76E–01b 7.28E–03bc 4.52E–03b 7.80E–04 1.72E–03 4.65E–04

Thyroid LAT Not applicable Not applicable Not applicable 4.92E–03 5.74E–03 3.27E–03

Eye/brain PA 1.79E–01c 1.01–03cd 8.32E–04c 7.80E–04 1.72E–03 4.65E–04

Eye/brain LAT Not applicable Not applicable Not applicable 4.92E–03 5.74E–03 3.27E–03

Ovaries PA 9.42E–01d 5.54E–03ef 4.37E–03 5.20E–05 1.14E–04 3.10E–05

Ovaries LAT Not applicable Not applicable Not applicable 7.50E–05 8.75E–05 4.99E–05

Urinary bladder/

prostate

PA 9.42E–01d 5.54E–03ef 4.37E–03 5.20E–05 1.14E–04 3.10E–05

Urinary bladder/ 

prostate

LAT Not applicable Not applicable Not applicable 7.50E–05 8.75E–05 4.99E–05

Colon/rectum PA 9.42E–01d 5.54E–03ef 4.37E–03 5.20E–05 1.14E–04 3.10E–05

Colon/rectum LAT Not applicable Not applicable Not applicable 7.50E–05 8.75E–05 4.99E–05

Testes PA 5.10E–02d 2.75E–04ef 2.37E–04 1.00E–07 2.20E–07 5.96E–08

Testes LAT Not applicable Not applicable Not applicable 3.00E–06 3.50E–06 2.00E–06

Lung (male) PA 2.35E+00 1.61E–02 1.09E–02 6.28E–03 1.38E–02 3.74E–03

Lung (male) LAT Not applicable Not applicable Not applicable 9.39E–03 1.10E–02 6.25E–03

Lung (female) PA 2.53E+00 1.71E–02 1.17E–02 6.74E–03 1.48E–02 4.02E–03

Lung (female) LAT Not applicable Not applicable Not applicable 1.05E–02 1.23E–02 7.01E–03

Liver/gall 

bladder/spleen/ 

pancreas

PA 2.53E+00 1.71E–02 1.17E–02 6.74E–03 1.48E–02 4.02E–03

Liver/gall 

bladder/spleen/ 

pancreas

LAT Not applicable Not applicable Not applicable 1.05E–02 1.23E–02 7.01E–03

Thymus PA 2.53E+00 1.71E–02 1.17E–02 6.74E–03 1.48E–02 4.02E–03

Thymus LAT Not applicable Not applicable Not applicable 1.05E–02 1.23E–02 7.01E–03

Esophagus PA 2.53E+00 1.71E–02 1.17E–02 6.74E–03 1.48E–02 4.02E–03

Esophagus LAT Not applicable Not applicable Not applicable 1.05E–02 1.23E–02 7.01E–03

Stomach PA 2.53E+00 1.71E–02 1.17E–02 6.74E–03 1.48E–02 4.02E–03

Stomach LAT Not applicable Not applicable Not applicable 1.05E–02 1.23E–02 7.01E–03

Bone Surface PA 2.53E+00 1.71E–02 1.17E–02 6.74E–03 1.48E–02 4.02E–03

Bone Surface LAT Not applicable Not applicable Not applicable 1.05E–02 1.23E–02 7.01E–03

Remainder PA 2.53E+00 1.71E–02 1.17E–02 6.74E–03 1.48E–02 4.02E–03

Remainder LAT Not applicable Not applicable Not applicable 1.05E–02 1.23E–02 7.01E–03

Breast PA 2.75E–01 1.54E–03 1.27E–03 1.16E–03 2.55E–03 6.92E–04

Breast LAT Not applicable Not applicable Not applicable 1.03E–02 1.20E–02 6.85E–03
Document No. ORAUT-TKBS-0009-3 Revision No. 02 Effective Date: 11/18/2019 Page 18 of 28

Organ Projection

April 1945–1956

GE; PFG 

(rem)

October 1944–1961

Westinghouse 

14 × 17 in.

(rem)

1962–1970

Westinghouse 

14 × 17 in.

rem)

1971–1986

Westinghouse 

14 × 17 in.

(rem)

1987–2000

Bennett

14 × 17 in.

(rem)

2001–May 2019 

Bennett 

14 × 17 in.

(rem)

Uterus PA 8.36E–01e 4.96E–03f 3.87E–03 5.20E–05 1.14E–04 3.10E–05

Uterus LAT Not applicable Not applicable Not applicable 6.30E–05 7.35E–05 4.19E–05

Bone marrow 

(male)

PA 5.16E–01 3.33E–03 2.39E–03 1.78E–03 3.92E–03 1.06E–03

Bone marrow 

(male)

LAT Not applicable Not applicable Not applicable 2.28E–03 2.66E–03 1.52E–03

Bone marrow 

(female)

PA 4.82E–01 3.04E–03 2.24E–03 1.72E–03 3.78E–03 1.03E–03

Bone marrow 

(female)

LAT Not applicable Not applicable Not applicable 1.77E–03 2.07E–03 1.18E–03

Entrance skin PA 6.62E+00f 6.36E–02f 3.51E–02f 1.42E–02f 3.12E–02f 8.47E–03

Entrance skin LAT Not applicable Not applicable Not applicable 4.26E–02f 4.97E–02f 2.83E–02

a. Dose conversion factors from Tables A.2 through A.9, ICRP (1982).

b. Dose conversion factor for anterior-posterior C-spine multiplied by depth dose correction factor of 0.20 as described in ORAUT-OTIB-0006 (2019). 

c. Dose conversion factor for PA chest.

d. Dose conversion factor for PA Abdominal used. 

e. Dose conversion factor for PA abdomen, because this organ is considered to be in the primary beam of a poorly collimated field.

f. Incident air kerma multiplied by a backscatter factor (NCRP 1989) of 1.18, 1.32, 1.35, or 1.42 for HVLs of 2.0, 2.5, and 4.0 mm Al, respectively.
Document No. ORAUT-TKBS-0009-3 Revision No. 02 Effective Date: 11/18/2019 Page 19 of 28

Table 3-11. Skin dose guidance and skin dose equivalents for chest projections, October 1944 through 1970.

a,b

Area of skin

PFG 

April 

1945–1956 

guidance

PFG

April 

1945–1956 

dose (rem)

PA chest 

October 

1944–1961 

guidance

PA chest

October 

1944–1961 

dose (rem)

PA chest 

1962–1970 

guidance

PA chest 

1962–1970 

dose (rem)

Right front shoulder EXSD 1.44E–01 EXSD 1.21E–03 EXSD 7.65E–04

Right back shoulder ENSD 6.62E+00 ENSD 6.36E–02 ENSD 3.51E–02

Left front shoulder EXSD 1.44E–01 EXSD 1.21E–03 EXSD 7.65E–04

Left back shoulder ENSD 6.62E+00 ENSD 6.36E–02 ENSD 3.51E–02

Right upper arm to elbow 10% ENSD 6.62E–01 ENSD 6.36E–02 ENSD 3.51E–02

Left upper arm to elbow 10% ENSD 6.62E–01 ENSD 6.36E–02 ENSD 3.51E–02

Left hand ENSD 6.62E+00 ENSD 6.36E–02 ENSD 3.51E–02

Right hand ENSD 6.62E+00 ENSD 6.36E–02 ENSD 3.51E–02

Left elbow, forearm, wrist 10% ENSD 6.62E–01 ENSD 6.36E–02 ENSD 3.51E–02

Right elbow, forearm, wrist 10% ENSD 6.62E–01 ENSD 6.36E–02 ENSD 3.51E–02

Right side of head (including ear and temple) 10% ENSD 6.62E–01 10% ENSD 6.36E–03 10% ENSD 3.51E–03

Left side of head (including ear and temple) 10% ENSD 6.62E–01 10% ENSD 6.36E–03 10% ENSD 3.51E–03

Front left thigh RSD (0.52 m) 9.26E–04 RSD (0.52 m) 1.58E–05 RSD (0.52m) 1.01E–05

Back left thigh RSD (0.52 m) 9.26E–04 RSD (0.52 m) 1.58E–05 RSD (0.52m) 1.01E–05

Front right thigh RSD (0.52 m) 9.26E–04 RSD (0.52 m) 1.58E–05 RSD (0.52m) 1.01E–05

Back right thigh RSD (0.52 m) 9.26E–04 RSD (0.52 m) 1.58E–05 RSD (0.52m) 1.01E–05

Left knee and below RSD (0.86 m) 3.39E–04 RSD (0.86 m) 5.77E–06 RSD (0.86m) 3.68E–06

Right knee and below RSD (0.86 m) 3.39E–04 RSD (0.86 m) 5.77E–06 RSD (0.86m) 3.68E–06

Left side of face Eye/brain 1.79E–01 Eye/brain 1.01E–03 Eye/Brain 8.32E–04

Right side of face Eye/brain 1.79E–01 Eye/brain 1.01E–03 Eye/Brain 8.32E–04

Left side of neck 10% ENSD 6.62E–01 ENSD 6.36E–02 ENSD 3.51E–02

Right side of neck 10% ENSD 6.62E–01 ENSD 6.36E–02 ENSD 3.51E–02

Back of head 10% ENSD 6.62E–01 10% ENSD 6.36E–03 10% ENSD 3.51E–03

Front of neck Eye/brain 1.79E–01 Eye/brain 1.01E–03 Eye/Brain 8.32E–04

Back of neck 10% ENSD 6.62E–01 ENSD 6.36E–02 ENSD 3.51E–02

Front torso: base of neck to end of sternum EXSD 1.44E–01 EXSD 1.21E–03 EXSD 8.32E–04

Front torso: end of sternum to lowest rib EXSD 1.44E–01 EXSD 1.21E–03 EXSD 8.32E–04

Front torso: lowest rib to iliac crest EXSD 1.44E–01 EXSD 1.21E–03 EXSD 8.32E–04

Front torso: iliac crest to pubis 10% EXSD 1.44E–02 10% EXSD 1.21E–04 10% EXSD 8.32E–05

Back torso: base of neck to mid–back ENSD 6.62E+00 ENSD 6.36E–02 ENSD 3.51E–02

Back torso: mid–back to lowest rib ENSD 6.62E+00 ENSD 6.36E–02 ENSD 3.51E–02

Back torso: lowest rib to iliac crest ENSD 6.62E+00 ENSD 6.36E–02 ENSD 3.51E–02

Back torso: buttocks (Iliac crest and below) 10% ENSD 6.62E–01 10% ENSD 6.36E–03 10% ENSD 3.51E–03

Right torso: base of neck to end of sternum ENSD 6.62E+00 ENSD 6.36E–02 ENSD 3.51E–02

Right torso: end of sternum to lowest rib ENSD 6.62E+00 ENSD 6.36E–02 ENSD 3.51E–02

Right torso: lowest rib to iliac crest ENSD 6.62E+00 ENSD 6.36E–02 ENSD 3.51E–02
Document No. ORAUT-TKBS-0009-3 Revision No. 02 Effective Date: 11/18/2019 Page 20 of 28

Area of skin

PFG 

April 

1945–1956 

guidance

PFG

April 

1945–1956 

dose (rem)

PA chest 

October 

1944–1961 

guidance

PA chest

October 

1944–1961 

dose (rem)

PA chest 

1962–1970 

guidance

PA chest 

1962–1970 

dose (rem)

Right torso: iliac crest to pubis (right hip) 10% ENSD 6.62E–01 10% ENSD 6.36E–03 10% ENSD 3.51E–03

Left torso: base of neck to end of sternum ENSD 6.62E+00 ENSD 6.36E–02 ENSD 3.51E–02

Left torso: end of sternum to lowest rib ENSD 6.62E+00 ENSD 6.36E–02 ENSD 3.51E–02

Left torso: lowest rib to iliac crest ENSD 6.62E+00 ENSD 6.36E–02 ENSD 3.51E–02

Left torso: iliac crest to pubis (left hip) 10% ENSD 6.62E–01 10% ENSD 6.36E–03 10% ENSD 3.51E–03

a. Values less than 0.1 mrem shown to one significant digit.

b. EXSD = exit skin dose; ENSD = entrance skin dose; RSD = remote skin dose.
Document No. ORAUT-TKBS-0009-3 Revision No. 02 Effective Date: 11/18/2019 Page 21 of 28

Table 3-12. Skin dose guidance and skin dose equivalents for chest projections, 1971 to May 15, 2019.

a,b

Area of skin

PA chest 

≥1971 

guidance

LAT chest 

≥1971 

guidance

1971–1986 

PA chest 

dose 

(rem)

1971–1986 

LAT chest

dose (rem)

1987–2000 

PA chest 

dose 

(rem)

1987–2000 

LAT chest 

dose 

(rem)

2001–May 

2019 

PA chest 

dose (rem)

2001–May 

2019 LAT

chest 

dose 

(rem)

Right front shoulder EXSD ENSD 4.83E–04 4.26E–02 1.06E–03 4.97E–02 2.88E–04 2.83E–02

Right back shoulder ENSD ENSD 1.42E–02 4.26E–02 3.12E–02 4.97E–02 8.47E–03 2.83E–02

Left front shoulder EXSD EXSD 4.83E–04 3.19E–04 1.06E–03 3.72E–04 2.88E–04 2.12E–04

Left back shoulder ENSD EXSD 1.42E–02 3.19E–04 3.12E–02 3.72E–04 8.47E–03 2.12E–04

Right upper arm to elbow 10% ENSD ENSD 1.42E–03 4.26E–02 3.12E–03 4.97E–02 8.47E–04 2.83E–02

Left upper arm to elbow 10% ENSD EXSD 1.42E–03 3.19E–04 3.12E–03 3.72E–04 8.47E–04 2.12E–04

Left hand 10% ENSD 10% ENSD 1.42E–03 4.26E–03 3.12E–03 4.97E–03 8.47E–04 2.83E–03

Right hand 10% ENSD 10% ENSD 1.42E–03 4.26E–03 3.12E–03 4.97E–03 8.47E–04 2.83E–03

Left elbow, forearm, wrist 10% ENSD 10% ENSD 1.42E–03 4.26E–03 3.12E–03 4.97E–03 8.47E–04 2.83E–03

Right elbow, forearm, wrist 10% ENSD 10% ENSD 1.42E–03 4.26E–03 3.12E–03 4.97E–03 8.47E–04 2.83E–03

Right side of head (including ear 

and temple)

10% ENSD 10% ENSD 1.42E–03 4.26E–03 3.12E–03 4.97E–03 8.47E–04 2.83E–03

Left side of head (including ear 

and temple)

10% ENSD 10% ENSD 1.42E–03 4.26E–03 3.12E–03 4.97E–03 8.47E–04 2.83E–03

Front left thigh RSD (0.52m) RSD (0.52m) 5.57E–06 8.08E–06 1.23E–05 9.43E–06 3.32E–06 5.38E–06

Back left thigh RSD (0.52m) RSD (0.52m) 5.57E–06 8.08E–06 1.23E–05 9.43E–06 3.32E–06 5.38E–06

Front right thigh RSD (0.52m) RSD (0.52m) 5.57E–06 8.08E–06 1.23E–05 9.43E–06 3.32E–06 5.38E–06

Back right thigh RSD (0.52m) RSD (0.52m) 5.57E–06 8.08E–06 1.23E–05 9.43E–06 3.32E–06 5.38E–06

Left knee and below RSD (0.86m) RSD (0.86m) 2.04E–06 2.95E–06 4.48E–06 3.45E–06 1.22E–06 1.97E–06

Right knee and below RSD (0.86m) RSD (0.86m) 2.04E–06 2.95E–06 4.48E–06 3.45E–06 1.22E–06 1.97E–06

Left side of face Eye/Brain 10% ENSD 7.80E–04 4.26E–03 1.72E–03 4.97E–03 4.65E–04 2.83E–03

Right side of face Eye/Brain 10% ENSD 7.80E–04 4.26E–03 1.72E–03 4.97E–03 4.65E–04 2.83E–03

Left side of neck 10% ENSD 10% ENSD 1.42E–03 4.26E–03 3.12E–03 4.97E–03 8.47E–04 2.83E–03

Right side of neck 10% ENSD 10% ENSD 1.42E–03 4.26E–03 3.12E–03 4.97E–03 8.47E–04 2.83E–03

Back of head 10% ENSD 10% ENSD 1.42E–03 4.26E–03 3.12E–03 4.97E–03 8.47E–04 2.83E–03

Front of neck Thyroid 10% ENSD 7.80E–04 4.26E–03 1.72E–03 4.97E–03 4.65E–04 2.83E–03

Back of neck 10% ENSD 10% ENSD 1.42E–03 4.26E–03 3.12E–03 4.97E–03 8.47E–04 2.83E–03

Front torso: base of neck to end 

of sternum

EXSD Lung 4.83E–04 1.05E–02 1.06E–03 1.23E–02 2.88E–04 7.01E–03

Front torso: end of sternum to 

lowest rib

EXSD Lung 4.83E–04 1.05E–02 1.06E–03 1.23E–02 2.88E–04 7.01E–03

Front torso: lowest rib to iliac 

crest

10% EXSD 10% Lung 4.83E–05 1.05E–03 1.06E–04 1.23E–03 2.88E–05 7.01E–04

Front torso: iliac crest to pubis 10% EXSD 10% Lung 4.83E–05 1.05E–03 1.06E–04 1.23E–03 2.88E–05 7.01E–04
Document No. ORAUT-TKBS-0009-3 Revision No. 02 Effective Date: 11/18/2019 Page 22 of 28

Area of skin

PA chest 

≥1971 

guidance

LAT chest 

≥1971 

guidance

1971–1986 

PA chest 

dose 

(rem)

1971–1986 

LAT chest

dose (rem)

1987–2000 

PA chest 

dose 

(rem)

1987–2000 

LAT chest 

dose 

(rem)

2001–May 

2019 

PA chest 

dose (rem)

2001–May 

2019 LAT

chest 

dose 

(rem)

Back torso: base of neck to 

mid–back

ENSD Lung 1.42E–02 1.05E–02 3.12E–02 1.23E–02 8.47E–03 7.01E–03

Back torso: mid–back to lowest 

rib

ENSD Lung 1.42E–02 1.05E–02 3.12E–02 1.23E–02 8.47E–03 7.01E–03

Back torso: lowest rib to iliac 

crest

10% ENSD 10% Lung 1.42E–03 1.05E–03 3.12E–03 1.23E–03 8.47E–04 7.01E–04

Back torso: buttocks (Iliac crest 

and below)

10% ENSD 10% Lung 1.42E–03 1.05E–03 3.12E–03 1.23E–03 8.47E–04 7.01E–04

Right torso: base of neck to end 

of sternum

ENSD ENSD 1.42E–02 4.26E–02 3.12E–02 4.97E–02 8.47E–03 2.83E–02

Right torso: end of sternum to 

lowest rib

ENSD ENSD 1.42E–02 4.26E–02 3.12E–02 4.97E–02 8.47E–03 2.83E–02

Right torso: lowest rib to iliac 

crest

10% ENSD 10% ENSD 1.42E–03 4.26E–03 3.12E–03 4.97E–03 8.47E–04 2.83E–03

Right torso: iliac crest to pubis 

(right hip)

10% ENSD 10% ENSD 1.42E–03 4.26E–03 3.12E–03 4.97E–03 8.47E–04 2.83E–03

Left torso: base of neck to end 

of sternum

ENSD EXSD 1.42E–02 3.19E–04 3.12E–02 3.72E–04 8.47E–03 2.12E–04

Left torso: end of sternum to 

lowest rib

ENSD EXSD 1.42E–02 3.19E–04 3.12E–02 3.72E–04 8.47E–03 2.12E–04

Left torso: lowest rib to iliac 

crest

10% ENSD 10% EXSD 1.42E–03 3.19E–05 3.12E–03 3.72E–05 8.47E–04 2.12E–05

Left torso: iliac crest to pubis 

(left hip)

10% ENSD 10% EXSD 1.42E–03 3.19E–05 3.12E–03 3.72E–05 8.47E–04 2.12E–05

a. Values less than 0.1 mrem shown to one significant digit.

b. EXSD = exit skin dose; ENSD = entrance skin dose; RSD = remote skin dose.
Document No. ORAUT-TKBS-0009-3 Revision No. 02 Effective Date: 11/18/2019 Page 23 of 28

 

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GLOSSARY

backscatter

Reflection or refraction of radiation at angles over 90 degrees from its original direction.

collimation

Restriction of the size of an X-ray beam by various types of beam limiting devices. Collimation 

of the X-ray beam to the size of the image receptor (typically film) is considered good practice.

dose

In general, the specific amount of energy from ionizing radiation that is absorbed per unit of 

mass. Effective and equivalent doses are in units of rem or sievert; other types of dose are in 

units of rad, rep, or grays.

dose conversion factor

The quotient of the organ absorbed dose or dose equivalent under specified conditions by the 

associated field quantity (e.g., air kerma or fluence). 

filtration

Process of filtering an X-ray beam, usually with millimeter thicknesses of aluminum material 

between the X-ray source and the film, that preferentially absorbs photons from the beam. 

Usually measured in equivalent millimeters of aluminum. See half-value layer. 

gaseous diffusion plant

Facility where uranium hexafluoride (UF6) gas is filtered to enrich the 235U and separate it from 

238U. The process requires enormous amounts of electric power and results in an increase in 

235U enrichment from 1% to about 3%.

gray (Gy)

International System unit of absorbed radiation dose, which is the amount of energy from any 

type of ionizing radiation deposited in any medium; 1 gray equals 1 joule per kilogram or 100 

rads.

grid

Device that consists of a series of thin, closely spaced lead strips that is placed between the 

person being X-rayed and the X-ray film to reduce interaction of scattered radiation with the 

film.

half-value layer (HVL)

Thickness of a specified substance, usually specified in equivalent millimeters of aluminum, 

which, when introduced in the path of a given beam of radiation, reduces the kerma rate by 

one-half. See filtration. 

kerma

Measure in units of absorbed dose (usually grays but sometimes rads) of the energy released 

by radiation from a given amount of a substance. Kerma is the sum of the initial kinetic 

energies of all the charged ionizing particles liberated by uncharged ionizing particles 

(neutrons and photons) per unit mass of a specified material. Free-in-air kerma refers to the 

amount of radiation at a location before adjustment for any external shielding from structures 

or terrain. The word derives from kinetic energy released per unit mass.
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kilovoltage (kVp)

Electrical potential difference in units of kilovolts between the cathode and the anode in an X 

ray generating tube. See technique.

lateral (LAT) 

Orientation of the body during an X-ray procedure in which the X-rays pass from one side of 

the body to the other. 

occupational medical dose

Dose from X-ray procedures performed for medical screening of workers as part of an 

occupational health program. Doses from X-rays used to diagnose diseases or injuries, even 

if incurred on the job, are not considered occupational and are therefore not eligible to be 

included in dose reconstruction under the Energy Employees Occupational Illness 

Compensation Program Act of 2000.

photofluorography (PFG)

Historical radiographic technique to produce chest images for screening a large number of 

people in a short period of time. The X-ray image produced on a fluorescent screen was 

photographed on 4- by 5-inch film. PFG was the primary method of screening large 

populations for tuberculosis before the advent of nonradiographic screening methods. Also 

called fluorography or mass miniature radiography. Not to be confused with fluoroscopy. 

posterior-anterior (PA)

Physical orientation of the body relative to a penetrating directional radiation field such that the 

radiation passes through the body from the back to the front. 

projection

Description of the path of an X-ray beam from the X-ray tube to the image receptor. For 

example, posterior-anterior and lateral are two common projections in chest radiography. The 

opposite of view. 

radiograph

Static images produced on radiographic film by gamma rays or X-rays after passing through 

matter. In the context of the Energy Employees Occupational Illness Compensation Program 

Act of 2000, radiographs are X-ray images of the various parts of the body used to screen for 

disease. 

source-to-skin distance

Distance from the X-ray machine target (anode) to the skin of the person being radiographed. 

This distance varies with the size of the person being radiographed.

standard error

The standard deviation of the sampling distribution of a statistic. For example, the standard 

error of the sample mean of n observations is sigma/sqrt(n), where sigma is the standard 

deviation of the original observations. 

stereoscopic

Noting or pertaining to simulated three-dimensional viewing of photographic or radiographic 

images with two views of the same image taken at slightly different angles.

technique

Combination of X-ray machine settings (technique factors) used to produce radiographs, which 

consists of the kilovoltage, tube current (milliamperes), and exposure time (seconds). The last 
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two parameters are often multiplied to yield the electric charge that has crossed the X-ray tube 

during the exposure in units of milliampere-seconds. Any combination of time and tube 

current that produces a given product in milliampere-seconds produces the same exposure for 

a fixed peak kilovoltage. Also called technic.

uncertainty

Standard deviation of the mean of a set of measurements. The standard error reduces to the 

standard deviation of the measurement when there is only one determination. See error. Also 

called standard error.

X-ray

(1) See X-ray radiation. (2) See radiograph.

X-ray radiation

Electromagnetic radiation (photons) produced by bombardment of atoms by accelerated 

particles. X-rays are produced by various mechanisms including bremsstrahlung and electron 

shell transitions within atoms (characteristic X-rays). Once formed, there is no difference 

between X-rays and gamma rays, but gamma photons originate inside the nucleus of an atom.