ORAU TEAM

Dose Reconstruction

Project for NIOSH

Oak Ridge Associated Universities I Dade Moeller & Associates I MJW Corporation

Page 1 of 20

Document Title:

Pantex Plant – Occupational Medical Dose

Document Number: ORAUT-TKBS-0013-3 

Revision: 02

Effective Date: 02/01/2007

Type of Document: TBD

Supersedes: Revision 01

Subject Expert(s): Robert C. Winslow and Elyse M. Thomas

Site Expert(s): Jerome B. Martin

Approval: Robert C. Winslow Signature on File for Approval Date: 01/24/2007

Jack J. Fix, Document Owner

Approval: Signature on File Approval Date: 01/12/2007

John M. Byrne, Task 3 Manager

Concurrence: Signature on File Concurrence Date: 01/12/2007

Edward F. Maher, Task 5 Manager

Concurrence: Signature on File Concurrence Date: 01/24/2007

Kate Kimpan, Project Director

Approval: Signature on File Approval Date: 02/01/2007

James W. Neton, Associate Director for Science

 New Total Rewrite Revision Page Change

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

REVISION AND DISCARD / DESTROY ALL COPIES OF THE PRIOR REVISION.
Document No. ORAUT-TKBS-0013-3 Revision No. 02 Effective Date: 02/01/2007 Page 2 of 20

PUBLICATION RECORD

EFFECTIVE 

DATE

REVISION 

NUMBER DESCRIPTION

08/24/2004 00 New technical basis document for the Pantex Plant – Occupational 

Medical Dose. First approved issue. Initiated by Jerome B. Martin.

12/23/2005 01 Approved issue of Revision 01. Training required: As determined by 

the Task Manager. Initiated by Dillard B. Shipler.

02/01/2007 02 Approved Revision 02 for organ dose assignment based on sitespecific information. Added Section 3-5, Skin Dose Method 

Description and Section 3-8, Attributions and Annotations. 

Incorporates internal formal and NIOSH formal review comments. 

Constitutes a total rewrite of document. This revision results in an 

increase in assigned dose and a PER is required. Initiated by Robert 

C. Winslow.
Document No. ORAUT-TKBS-0013-3 Revision No. 02 Effective Date: 02/01/2007 Page 3 of 20

TABLE OF CONTENTS

SECTION TITLE

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

PAGE

4

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

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

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

3.2 Examination Types and Frequencies .......................................................................................6

3.3 Equipment and Techniques......................................................................................................6

3.3.1 Photofluorography ........................................................................................................7

3.3.2 X-Ray Machines ...........................................................................................................7

3.3.3 Specific Technique Charts............................................................................................8

3.4 Organ Dose Calculations .........................................................................................................9

3.5 Skin Dose Method Description ................................................................................................. 9

3.6 Uncertainty Analysis...............................................................................................................13

3.7 Instruction Guide for Dose Reconstructors............................................................................. 15

3.8 Attributions and Annotations .................................................................................................. 15

References ........................................................................................................................................17

Glossary ............................................................................................................................................19

LIST OF TABLES

TABLE TITLE

3-1 Pantex worker X-ray examinations...........................................................................................

PAGE

6

3-2 Technique factors for PA chest X-rays .....................................................................................8

3-3 Technique factors for AP lumbar spine X-rays ......................................................................... 8

3-4 Technique factors for LAT lumbar spine X-rays........................................................................ 8

3-5 Calculated organ dose for PA chest X-rays before 1967 assuming 

minimal collimation................................................................................................................. 10

3-6 Calculated organ dose for PA chest X-rays, 1967 to 1971 ..................................................... 11

3-7 Calculated organ doses for PA chest X-rays, 1972 to 1990.................................................... 12

3-8 Calculated organ doses for PA chest X-rays, 1991 to 2004 .................................................... 13

3-9 Organ dose estimates for lumbar spine AP and LAT X-rays before 

January 1,1982 ......................................................................................................................14

3-10 Summary of dose reconstruction recommendations............................................................... 15
Document No. ORAUT-TKBS-0013-3 Revision No. 02 Effective Date: 02/01/2007 Page 4 of 20

ACRONYMS AND ABBREVIATIONS

AP anterior-posterior

cGy centigray

CHP Certified Health Physicist

cm centimeter

DCF dose conversion factor

DOE U.S. Department of Energy

EEOICPA Energy Employees Occupational Illness Compensation Program Act of 2000

ESE entrance skin exposure

GE General Electric Company

Gy gray

HVL half-value layer

ICRP International Commission on Radiological Protection

in. inch

IREP Interactive RadioEpidemiological Program

kVp kilovolts-peak, applied kilovoltage

LAT lateral

m meter

mA milliampere

mAs milliampere-second

mGy milligray

mm millimeter

mR milliroentgen

NCRP National Council on Radiation Protection and Measurements

NIOSH National Institute for Occupational Safety and Health

ORAU Oak Ridge Associated Universities

PA posterior-anterior

POC probability of causation

R roentgen

s second

TBD technical basis document

U.S.C. United States Code

yr year

§ section or sections
Document No. ORAUT-TKBS-0013-3 Revision No. 02 Effective Date: 02/01/2007 Page 5 of 20

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 historic background information and guidance to assist in the preparation of 

dose reconstructions at particular sites or categories of sites. They will be revised in the event 

additional relevant information is obtained about the affected site(s). These documents may be used 

to assist NIOSH staff in the completion of the individual work required for each dose reconstruction.

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

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

employer facility” or a “Department of Energy [DOE] facility” as defined in the Energy Employees 

Occupational Illness Compensation Program Act [EEOICPA; 42 U.S.C. § 7384l(5) and (12)]. 

EEOICPA defines a DOE facility 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 Department of Energy (except for buildings, structures, premises, 

grounds, or operations ... pertaining to the Naval Nuclear Propulsion Program)” [42 U.S.C. 

§ 7384l(12)]. Accordingly, except for the exclusion for the Naval Nuclear Propulsion Program noted 

above, any facility that performs or performed DOE operations of any nature whatsoever is a DOE 

facility encompassed by EEOICPA.

For employees of DOE or its contractors with cancer, the DOE facility definition only determines 

eligibility for a dose reconstruction, which is a prerequisite to a compensation decision (except for 

members of the Special Exposure Cohort). The compensation decision for cancer claimants is based 

on a section of the statute entitled “Exposure in the Performance of Duty.” That provision [42 U.S.C. 

§ 7384n(b)] says that an individual with cancer “shall be determined to have sustained that cancer in 

the performance of duty for purposes of the compensation program if, and only if, the cancer ... was 

at least as likely as not related to employment at the facility [where the employee worked], as 

determined in accordance with the POC [probability of causation1

As noted above, the statute includes a definition of a DOE facility that excludes “buildings, structures, 

premises, grounds, or operations covered by Executive Order No. 12344, dated February 1, 1982 

(42 U.S.C. 7158 note), pertaining to the Naval Nuclear Propulsion Program” [42 U.S.C. § 7384l(12)]. 

While this definition contains an exclusion with respect to the Naval Nuclear Propulsion Program, the 

section of EEOICPA that deals with the compensation decision for covered employees with cancer 

[i.e., 42 U.S.C. § 7384n(b), entitled “Exposure in the Performance of Duty”] does not contain such an 

exclusion. Therefore, the statute requires NIOSH to include all occupationally derived radiation 

exposures at covered facilities in its dose reconstructions for employees at DOE facilities, including 

radiation exposures related to the Naval Nuclear Propulsion Program. As a result, all internal and 

external dosimetry monitoring results are considered valid for use in dose reconstruction. No efforts 

are made to determine the eligibility of any fraction of total measured exposure for inclusion in dose 

reconstruction. NIOSH, however, does not consider the following exposures to be occupationally 

derived:

] guidelines established under 

subsection (c) ...” [42 U.S.C. § 7384n(b)]. Neither the statute nor the probability of causation

guidelines (nor the dose reconstruction regulation) define “performance of duty” for DOE employees 

with a covered cancer or restrict the “duty” to nuclear weapons work.

• Radiation from naturally occurring radon present in conventional structures

• Radiation from diagnostic X-rays received in the treatment of work-related injuries

 

1 The U.S. Department of Labor is ultimately responsible under the EEOICPA for determining the POC.
Document No. ORAUT-TKBS-0013-3 Revision No. 02 Effective Date: 02/01/2007 Page 6 of 20

3.1.1

The purpose of this TBD is to describe the Pantex Plant occupational medical X-ray systems and 

practices. The Oak Ridge Associated Universities (ORAU) Team will use this information as needed 

to evaluate medical X-ray doses for EEOICPA claims.

Purpose

3.1.2

Pantex operations have played an important role in the U.S. nuclear weapons program. Historically, 

Pantex provided several roles associated with the assembly, disassembly, retrofit, and modification of 

nuclear weapon systems (Mitchell 2003). Today, Pantex continues to fabricate high explosives and to 

assemble nuclear weapons. The principal operations at this site, however, are the dismantling of 

retired nuclear weapons and the maintenance of the nation’s nuclear weapons stockpile. Pantex, 

which is operated by DOE’s Office of Defense Programs, is the only facility in the United States that 

performs these operations.

Scope

The methods used for occupational medical X-rays have evolved since the beginning of Pantex 

operations. An objective of this document is to provide a technical basis to evaluate the dose 

received by workers from medical X-ray procedures. This document presents the organ doses from 

the screening medical procedures performed at Pantex for input to the NIOSH Interactive 

RadioEpidemiological Program (IREP).

3.2 EXAMINATION TYPES AND FREQUENCIES

Pantex required preemployment and routine physical examinations as part of its occupational health 

and safety program. The Medical Department maintains a log for each worker of what appears to be 

all X-ray examinations. An inspection of the logs for selected long-term workers showed that there 

was not a consistent pattern in the frequency of their examinations. Based on this inspection, 

practices apparently varied among workers, probably based on occupation and job responsibilities. 

Table 3-1 summarizes general patterns and default dose reconstruction recommendations. 

Table 3-1. Pantex worker X-ray examinations.

a

Period Examination Frequency Default dose reconstruction recommendation

1952–1981 PA chest For some workers, on 

employment and annual

Use log of X-ray examinations to identify occupationrelated examinations for PA chest, AP lumbar spine, 

and LAT lumbar spine examinations. If log is not 

available in claim documentation, assume 

preemployment PA chest, AP lumbar spine, and LAT 

lumbar spine examinations and annual PA chest 

examinations. 

AP lumbar 

spine 

For some workers, men 

only, preemployment

LAT lumbar 

spine 

For some workers, men 

only, preemployment

1982–2004 PA chest For some workers, on 

employment and every 

5 yr

Use log of X-ray examinations to identify occupationrelated PA chest examinations. If log is not available in 

claim documentation, assume preemployment PA 

chest and a reexamination every 5 yr. 

a. AP = anterior-posterior; LAT = lateral; PA = posterior-anterior.

3.3 EQUIPMENT AND TECHNIQUES

A complete history of Pantex X-ray equipment manufacturers, models, examination techniques, and 

exposure rates for these techniques has not been identified. Therefore, dose reconstruction must 

utilize assumptions favorable to claimants described in the latest revision of ORAUT (2005). 
Document No. ORAUT-TKBS-0013-3 Revision No. 02 Effective Date: 02/01/2007 Page 7 of 20

Section 3.6 summarizes the recommended approach for dose reconstructors. The following 

paragraphs summarize available historical information.

3.3.1

This TBD analysis examined X-ray film records for long-term Pantex workers who began work in the 

early 1950s to determine if the Plant used photofluorography techniques for chest X-rays. All the 

records showed full-size 14- by 17-in. films for all years for which there were records, which include

1952, 1954 to 1956, 1958 to 1959, 1962, 1964 to 1966, 1968, 1970 to 1979, and 1982. These 

observations, along with conversations with Pantex employees, led to the conclusion that Pantex 

never used photofluorography.

Photofluorography

3.3.2

Historical records have been obtained for four X-ray machines at Pantex, as follows:

X-Ray Machines

• General Electric: The earliest record found of a specific X-ray machine at Pantex involved a 

September 26, 1967, inspection, using Public Health Service Form 4495-3 (PHS 1967), of 

medical X-ray facilities. The inspector identified the control panel manufacturer and tube head 

manufacturer and model as General Electric, and identified the film as GAF Supreme with 

RADLIN T intensifying screens. Another survey of the medical X-ray facilities at Pantex 

occurred from August 13 to 18, 1970; the inspector found a General Electric control panel and 

a Profexray Model AZ Type 2 tube head (PHS 1970). 

• Picker: From approximately July 11, 1972, to 1984, Pantex used a Picker X-Ray Pictronic 

500 with a Picker X-Ray Style 2098 tube head. Half-value layer (HVL) measurements in 1972 

were greater than 0.6 mm Al at 49 kVp and greater than 1.6 mm Al at 70 kVp (Alexander 

1972a). In 1983, an evaluation of the actual number of pulses that occurred with different 

timer settings showed a variation from the time setting of –10% (at 0.5 s) to +33% (at 1/15 s) 

(Ikenberry 1983). Timer problems with this machine persisted through its replacement in the 

spring of 1984 (Ikenberry 1984). In 1983, HVL measurements were greater than 0.6 mm Al at 

45 kVp, greater than 1.6 mm Al at 70 kVp, and greater than 2.6 mm Al at 90 kVp. Kodak BB-5 

Blue brand film and DuPont Par screens were used (Ikenberry 1983).

• Universal: A Universal X-Ray control panel with a Eureka X-Ray Tube Company Model 

Sapphire 150 tube head was installed between March 19 and May 25, 1984. The unit was in 

service through at least November 1, 1993. All tested parameters were apparently excellent. 

HVL measurements were greater than 0.6 mm Al at 45 kVp, greater than 1.6 mm Al at 70 kVp, 

and greater than 2.6 mm Al at 90 kVp (Hill 1984). Kodak BB-5 Blue brand film and DuPont 

Par screens were used through 1990, after which DuPont Cronex 7 film was used with Cronex 

Quanta III screens (Kelly 1990). The first entrance skin exposure (ESE) for PA chest 

radiography was 4.4 mR measured on September 16, 1993, for a 23-cm-thick phantom at 

192-cm source-to-image distance, 300 mA, and 72 kVp with a large focal spot and no grid 

(PHS 1993). 

• Continental: A Continental TM-50 6626.235 X-ray machine was installed between November 

1, 1993, and November 6, 1995. On November 6, 1995, several measurements of X-ray

exposure at 30 in. for selected kVps between 60 and 100 in increments of 10 were performed

(Huddleston 1995). For chest films, the measured value of 0.913 R for 100 mAs at 30 in. for 

80 kVp was converted to the distance of 62 in. for a PA chest radiograph. The calculated 

value is 0.21 R for 100 mAs, and this value is equivalent to 0.02 cGy for the typical 10-mAs PA 
Document No. ORAUT-TKBS-0013-3 Revision No. 02 Effective Date: 02/01/2007 Page 8 of 20

chest examination. This machine uses photo-timing, which measures the incidence on the film 

directly during irradiation to determine the exposure time. This machine was in use as of June 

2004 (Huddleston 1995). 

There is evidence of ongoing Pantex reviews of the X-ray equipment and techniques (Gidley 1970; 

Alexander 1972b,c). 

3.3.3

A table obtained from the Pantex Medical Department of suggested X-ray techniques by GE in 1941 

(GE 1941) implies that Pantex probably used a GE CRT 1 or CRT 2 X-ray tube operated “on full wave 

rectification” with “fast” film in the early days. A 1967 table of desk instructions of X-ray examination 

steps (Pantex 1967) shows close similarity to the 1941 table. Measurements of the entrance kerma 

for the Pantex X-ray equipment and techniques have not been found for years before 1995 for the 

Continental X-ray machine. The entrance kerma calculated based on the information in the GE 

(1941) and Pantex (1967) technique charts, in addition to the measured beam output for the 

Continental system (Huddleston 1995), has been used in Tables 3-2, 3-3, and 3-4, which provide the 

technique factors for PA chest, AP lumbar spine, and LAT lumbar spine projections, respectively. 

Specific Technique Charts

Table 3-2. Technique factors for PA chest X-rays. 

Period

Total filtration 

(mm Al)

HVL

(mm Al)

Current 

(mA)

Voltage

(kVp)

Exposure time

(s)

Entrance kerma 

(cGy)

Pre-1967 1.5 1.6a 200b 70 1/20 0.0256c

1967–1990 1.5 1.6a 100d 70 1/10 0.0256c

1991–2004 4.0 4.8e Unknown ~80 (f) 0.0044e

a. 2.5-mm Al HVL was assumed for the determination of organ dose conversion factors (DCFs) using International 

Commission on Radiological Protection (ICRP) Publication 34 (ICRP 1982) as an assumption favorable to claimants. [1]

b. Based on X-ray techniques chart (GE 1941) corrected for 24-cm-thick individual.

c. Calculated based on information from NCRP (1989, Table B.3), and corrected to 1.5-mm Al equivalent filtration. [1]

d. Based on Pantex (1967) chart 

e. Huddleston (1995). [2]

f. System has photo-timing; used 0.1 s and 100 mA in calculations of entrance kerma.

Table 3-3. Technique factors for AP lumbar spine X-rays. 

Period

Total filtration 

(mm Al)

HVL

(mm Al)

Current 

(mA)

Voltage

(kVp)

Exposure time

(s)

Entrance kerma 

(cGy)

Pre-1967–1981 1.5 1.6a 100b 70b 1b 1.34c

1982–2004 Not performed

a. 2.5-mm Al HVL was assumed for the determination of organ DCFs using ICRP (1982) as an assumption favorable to

claimants. [1]

b. Based on GE X-ray techniques chart (GE 1941) and Pantex technique chart (Pantex 1967) corrected for 24-cm-thick 

individual. 

c. Calculated based on information from NCRP (1989, Table B.3) and corrected to 1.5-mm Al equivalent filtration. [2]

Table 3-4. Technique factors for LAT lumbar spine X-rays. 

Period

Total filtration 

(mm Al)

HVL

(mm Al)

Current 

(mA)

Voltage

(kVp)

Exposure time

(s)

Entrance kerma 

(cGy)

Pre-1967–1981 1.5 1.85a 100b 86b 2b 3.71c

1982–2004 Not performed

a. 2.5-mm Al HVL was assumed for the determination of organ DCFs using ICRP (1982) as an assumption favorable to 

claimants. [1]

b. Based on GE X-ray techniques chart (GE 1941) and Pantex technique chart (Pantex 1967) corrected for 24-cm-thick 

individual. 

c. Calculated based on information from NCRP (1989, Table B.3) and corrected to 1.5-mm Al equivalent filtration. [2]
Document No. ORAUT-TKBS-0013-3 Revision No. 02 Effective Date: 02/01/2007 Page 9 of 20

3.4 ORGAN DOSE CALCULATIONS

Organ dose calculations for workers at Pantex from 1952 to the present involve three primary medical 

radiographic procedures administered in connection with preemployment and regular medical 

screening examinations: 

• 14- by 17-in. PA chest film (preemployment and annual through 1981 and approximately every 

5 yr thereafter) 

• AP lumbar spine film (men only; preemployment only)

• LAT lumbar spine film (men only; preemployment only)

The analysis for this TBD evaluated only doses from these three techniques. Other radiographic 

examinations of Pantex employees that could have occurred are likely to be nonoccupational in the 

sense that they were associated with illness or injury and were not part of a routine screening 

process. There is no indication in the examined records that the occupational medical program 

routinely administered other radiographic examinations for screening. The analysis used the 

measurements performed for the Continental X-ray and techniques in 1995 (Huddleston 1995). This 

analysis assumed that an exposure of 1 R is equivalent to a kerma of 1 rad and to 10 mGy or 1 rem 

(ORAUT 2005). Tables 3-5 to 3-8 summarize organ doses for PA chest examinations for the various 

periods. 

The purpose of preemployment AP and LAT lumbar spine examinations was to determine if 

individuals had preexisting back problems before hiring them for certain occupations. Little 

information has been found about these examinations. If there is not more specific information on the 

individual's log of worker X-ray examinations, dose reconstructors should use the assumption that AP 

and LAT lumbar spine examinations were conducted for each male worker employed before 1982 at 

preemployment only. Table 3-9 lists the organ doses for AP lumbar spine and LAT lumbar spine 

examinations. Pantex-specific documentation indicates the beam size for lumbar spine examinations 

was 12 inches, which indicates that collimation was used for these procedures (PHS 1967). 

3.5 SKIN DOSE METHOD DESCRIPTION

Skin doses from AP chest projections are calculated differently dependent on proximity of the affected 

skin area to the primary beam. The following quantities are calculated: Primary beam entrance skin 

dose ENSD, primary beam exit skin dose EXSD, entrance skin dose outside but near the primary 

beam ENSDNPB, exit skin dose outside but near the primary beam EXSDNPB, and remote skin dose 

RSD. 

ENSD is the product of ESE and a backscatter factor BF as shown in Equation 3-1. The BF is from 

Table B-8 of National Council on Radiation Protection and Measurements (NRCP) Report 102 (NCRP 

1989) or from empirical data. This dose applies to all skin surfaces in the beam on the entrance side 

of the body. For collimated PA chest projections this includes the skin of the back, neck, and 

shoulders. For uncollimated PA chest projections this includes the skin of the back, neck, shoulders, 

back of the head, ears, upper arms, elbows, lower arms, and buttocks.

ENSD ×= BFESE (3-1)
Document No. ORAUT-TKBS-0013-3 Revision No. 02 Effective Date: 02/01/2007 Page 10 of 20

Table 3-5. Calculated organ dose for PA chest X-rays before 1967 assuming minimal collimation. 

Organ

DCF (mGy/Gy air kerma)

(beam quality for 2.5-mm Al HVL)a Organ dose (rem)

Thyroidb 174 4.45E-03

Eye/brainc 174 4.45E-03

Ovariesd 168 4.30E-03

Urinary bladder 168 4.30E-03

Colon/rectum 168 4.30E-03

Testes 9.1 2.30E-04

Lungs 451 1.15E-02

Thymus 451 1.15E-02

Esophagus 451 1.15E-02

Stomach 451 1.15E-02

Bone surfaces 451 1.15E-02

Liver/gall bladder/spleen 451 1.15E-02

Remainder 451 1.15E-02

Female breast 49 1.25E-03

Uteruse 149 3.81E-03

Bone marrow 92 2.36E-03

Entrance skin dose in primary beamf N/A 3.46E-02

Exit skin dose in primary beamg N/A 8.60E-04

Entrance skin dose near but outside primary beamg N/A 3.46E-03

Exit skin dose near but outside primary beamg N/A 8.60E-05

Remote skin dose–thighs to kneesg N/A 9.91E-06

Remote skin dose–knees to anklesg N/A 3.62E-06

Remote skin dose–anklesg N/A 1.64E-06

a. DCFs from ICRP (1982, Tables A.2 to A.8); N/A = not applicable. [1]

b. The DCF for the thyroid is based on ICRP (1982, Table A.2) for a cervical spine procedure and a depth dose correction 

factor of 0.2. [1]

c. The DCF for the eye/brain is based on the thyroid in ICRP (1982, Table A.2) for a cervical spine procedure and a depth 

dose correction factor of 0.2. [1]

d. The DCF for the ovaries is based on ICRP (1982, Table A.3) for an abdominal procedure. [1]

e. The DCF for the uterus is based on ICRP (1982, Table A.7) for an abdominal procedure. [1]

f. Skin dose was determined by multiplying ESE by a backscatter of 1.35 for an HVL of 2.5 mm Al. From NCRP (1989, 

Table B-8). [1]

g. Calculated based on Section 3.5. [3]

EXSD is the ENSD divided by an adjusted absorption factor AFF, which is the absorption factor for a 

23-cm chest or 23-cm abdomen tabulated in Table B.7 of NCRP Report 102 (NCRP 1989) decreased 

by 10% as shown in Equations 3-2 and 3-3; this factor is favorable to claimants. This dose applies to 

all skin surfaces in the beam on the exit side of the body. For collimated PA chest projections this 

includes the skin of the chest, neck, front side of the shoulders, and upper abdomen. For 

uncollimated PA chest projections this includes the skin of the chest, neck, front side of the shoulders, 

upper abdomen, lower abdomen and face.

AFF EXSD = ENSD (3-2)

AFF AF ×= 9.0 (3-3)
Document No. ORAUT-TKBS-0013-3 Revision No. 02 Effective Date: 02/01/2007 Page 11 of 20

Table 3-6. Calculated organ dose for PA chest X-rays, 1967 to 1971. 

Organ

DCF (mGy/Gy air kerma)

(beam quality for 2.5-mm Al HVL)a Organ dose (rem)

Thyroidb 174 4.45E-03

Eye/brainc 174 4.45E-03

Ovariesd 168 4.30E-03

Urinary bladder 168 4.30E-03

Colon/rectum 168 4.30E-03

Testes 9.1 2.30E-04

Lungs 451 1.15E-02

Thymus 451 1.15E-02

Esophagus 451 1.15E-02

Stomach 451 1.15E-02

Bone surfaces 451 1.15E-02

Liver/gall bladder/spleen 451 1.15E-02

Remainder 451 1.15E-02

Female breast 49 1.25E-03

Uteruse 149 3.81E-03

Bone marrow 92 2.36E-03

Entrance skin dose in primary beamf N/A 3.46E-02

Exit skin dose in primary beamg N/A 8.60E-04

Entrance skin dose near but outside primary beamg N/A 3.46E-03

Exit skin dose near but outside primary beamg N/A 8.60E-05

Remote skin dose–thighs to kneesg N/A 9.91E-06

Remote skin dose–knees to anklesg N/A 3.62E-06

Remote skin dose–anklesg N/A 1.64E-06

a. DCFs from ICRP (1982, Tables A.2 to A.8); N/A = not applicable. [1]

b. The DCF for the thyroid is based on ICRP (1982, Table A.2) for a cervical spine procedure and a depth dose correction 

factor of 0.2. [1]

c. The DCF for the eye/brain is based on the thyroid in ICRP (1982, Table A.2) for a cervical spine procedure and a depth 

dose correction factor of 0.2. [1]

d. The DCF for the ovaries is based on ICRP (1982, Table A.3) for an abdominal procedure. [1]

e. The DCF for the uterus is based on ICRP (1982, Table A.7) for an abdominal procedure. [1]

f. Skin dose was determined by multiplying ESE by a backscatter of 1.35 for an HVL of 2.5 mm Al. From NCRP (1989, 

Table B-8). [1]

g. Calculated based on Section 3.5. [3]

ENSDNPB is 10% of the ENSD as shown in Equation 3-4. This equation is assumed based on a 

tabulated value in International Commission on Radiological Protection (ICRP) Publication 34 that 

shows that testes dose is 10% of the central beam dose when the testes are just outside the primary 

beam (ICRP 1982).

ENSDNPB ENSD ×= 1.0 (3-4)

EXSDNPB is similarly 10% of the EXSD as shown in Equation 3-5. 

EXSDNPB EXSD 1.0×= (3-5)

RSD, shown in Equation 3-6, is a function of:

• ENSD

• Inverse square of the distance R from the center of the primary beam to nearest point on the 

skin surface of interest
Document No. ORAUT-TKBS-0013-3 Revision No. 02 Effective Date: 02/01/2007 Page 12 of 20

Table 3-7. Calculated organ doses for PA chest X-rays, 1972 to 1990. 

Organ

DCF (mGy/Gy air kerma)

(beam quality for 2.5-mm Al HVL)a Organ dose (rem)

Thyroid 32 8.19E-04

Eye/brain 32 8.19E-04

Ovaries 1 2.56E-05

Urinary bladder 1 2.56E-05

Colon/rectum 1 2.56E-05

Testes 0.01 2.56E-07

Lungs 451 1.15E-02

Thymus 451 1.15E-02

Esophagus 451 1.15E-02

Stomach 451 1.15E-02

Bone surfaces 451 1.15E-02

Liver/gall bladder/spleen 451 1.15E-02

Remainder 451 1.15E-02

Female breast 49 1.25E-03

Uterus 1.3 3.33E-05

Bone marrow 92 2.36E-03

Entrance skin dose in primary beamb N/A 3.46E-02

Exit skin dose in primary beamc N/A 8.60E-04

Entrance skin dose near but outside primary beamc N/A 3.46E-03

Exit skin dose near but outside primary beamc N/A 8.60E-05

Remote skin dose–thighs to kneesc N/A 9.91E-06

Remote skin dose–knees to anklesc N/A 3.62E-06

Remote skin dose–anklesc N/A 1.64E-06

a. DCFs from ICRP (1982, Tables A.2 to A.8); N/A = not applicable. [1]

b. Skin dose was determined by multiplying ESE by a backscatter of 1.35 for an HVL of 2.5 mm Al. From NCRP (1989, 

Table B-8). [1]

c. Calculated based on Section 3.5. [3]

• A ratio of scattered to incident exposure equal to 0.0005 based on the exposure at 1 m due to 

90° scattering of 70-kVp radiation in accordance with Table B-2 of NCRP Report 49 (NCRP 

1976)

• Average percent depth dose ADD at the midpoint of a 23-cm torso (rounded to 12 cm to match 

the nearest tabulated value and to ensure bias favorable to claimants) based on the HVL of 

the beam as tabulated in NCRP Report 102 (NCRP 1989, Table B.8) for the PA chest and AP 

lumbar spine procedures 

• Average percent depth dose ADD at the midpoint of a 35-cm torso (rounded to 16 cm to match 

the nearest tabulated value and to ensure bias favorable to claimants) based on the HVL of 

the beam as tabulated in NCRP Report 102 (NCRP 1989, Table B.8) for the LAT lumbar spine 

procedures

• A bias factor favorable to claimants of 1.1 to allow for 10% uncertainty in tabulated values of 

ADD

2 1 .0 0005 1.1 



 





××××=

R

RSD ENSD ADD (3-6)
Document No. ORAUT-TKBS-0013-3 Revision No. 02 Effective Date: 02/01/2007 Page 13 of 20

Table 3-8. Calculated organ doses for PA chest X-rays, 1991 to 2004. 

Organ

DCF (mGy/Gy air kerma)

(beam quality for 5.0-mm Al HVL)a Organ dose (rem)

Thyroid 110 4.84E-04

Eye/brain 110 4.84E-04

Ovaries 13.2 5.81E-05

Urinary bladder 13.2 5.81E-05

Colon/rectum 13.2 5.81E-05

Testes 0.01 4.40E-08

Lungs 802 3.53E-03

Thymus 802 3.53E-03

Esophagus 802 3.53E-03

Stomach 802 3.53E-03

Bone surfaces 802 3.53E-03

Liver/gall bladder/spleen 802 3.53E-03

Remainder 802 3.53E-03

Female breast 166 7.30E-04

Uterus 11.2 4.93E-05

Bone marrow 258 1.14E-03

Entrance skin dose in primary beamb N/A 6. 60E-03

Exit skin dose in primary beamc N/A 3.31E-04

Entrance skin dose near but outside primary beamc N/A 6.60E-04

Exit skin dose near but outside primary beamc N/A 3.31E-05

Remote skin dose–thighs to kneesc N/A 3.03E-06

Remote skin dose–knees to anklesc N/A 1.11E-06

Remote skin dose–anklesc N/A 5.01E-07

a. DCFs extrapolated from ICRP (1982, Tables A.2 to A.8) extrapolated to 5.0 mm Al HVL; N/A = not applicable. [2]

b. Skin dose was determined by multiplying ESE by a backscatter of 1.5 for an HVL of 5.0 mm Al. Extrapolated based on 

information from NCRP (1989, Table B-8). [2]

c. Calculated based on Section 3.5. [3]

The distances used for calculation of the RSD for the PA chest X-ray procedures were: 

• Thighs to knees – 0.52 m

• Knees to ankles – 0.86 m

• Ankles – 1.28 m

The distances used for calculation of the RSD for the AP and LAT lumbar-spine procedures were:

• Thighs to knees – 0.26 m

• Knees to ankles – 0.60 m

• Ankles – 1.02 m

3.6 UNCERTAINTY ANALYSIS

The description of error and uncertainty in ORAUT (2005) is directly applicable to the evaluation of 

medical X-ray doses to Pantex workers. Available historical documentation is sufficient to ensure 

analysis of the dose that is favorable to claimants. Dose reconstructors should use the 

recommendation from ORAUT (2005) to assume that errors are all positive (i.e., only +30%) for 

Pantex workers. 
Document No. ORAUT-TKBS-0013-3 Revision No. 02 Effective Date: 02/01/2007 Page 14 of 20

Table 3-9. Organ dose estimates for lumbar spine AP and LAT X-rays before 

January 1, 1982. 

Organ View

DCF 

(mGy/Gy air kerma)

(beam quality for 2.5 mm Al HVL)a

Organ dose

(rem)

Thyroid AP 0.3 4.02E-04

LAT 0.01 3.71E-05

Eye/brain AP 0.3 4.02E-04

LAT 0.01 3.71E-05

Ovaries AP 216 2.89E-01

LAT 47 1.74E-01

Urinary bladder AP 216 2.89E-01

LAT 47 1.74E-01

Colon/rectum AP 216 2.89E-01

LAT 47 1.74E-01

Testesb AP 18 2.41E-02

LAT 3.3 1.22E-02

Lungs AP 79 1.06E-01

LAT 14 5.19E-02

Thymus AP 79 1.06E-01

LAT 14 5.19E-02

Esophagus AP 79 1.06E-01

LAT 14 5.19E-02

Stomach AP 79 1.06E-01

LAT 14 5.19E-02

Bone surfaces AP 79 1.06E-01

LAT 14 5.19E-02

Liver/gall bladder/spleen AP 79 1.06E-01

LAT 14 5.19E-02

Remainder AP 79 1.06E-01

LAT 14 5.19E-02

Breastc AP 25 3.35E-02

LAT 13 4.82E-02

Uterus AP 287 3.85E-01

LAT 31 1.15E-01

Bone marrow AP 37 4.96E-02

LAT 22 8.16E-02

Entrance skin dose in primary 

beamd

AP N/A 1.81E+00

LAT N/A 5.01E+00

Exit skin dose in primary beame AP N/A 4.50E-02

LAT N/A 1.95E-01

Entrance skin dose near but 

outside primary beame

AP N/A 1.81E-01

LAT N/A 5.01E-01

Exit skin dose near but outside 

primary beame

AP N/A 4.50E-03

LAT N/A 1.95E-02

Remote skin dose–thighs to 

kneese

AP N/A 2.08E.03

LAT N/A 3.06E-03

Remote skin dose–knees to 

anklese

AP N/A 3.90E-04

LAT N/A 5.74E-04

Remote skin dose–anklese AP N/A 1.35E-04

LAT N/A 1.99E-04

a. DCFs from ICRP (1982, Tables A.2 to A.8); N/A = not applicable. [1]

b. DCFs based on abdominal projection from ICRP (1982, Table A.4). [1]

c. DCFs based on upper gastrointestinal projection from ICRP (1982, Table A.6). [1]

d. Dose based on multiplying entrance kerma by a backscatter of 1.35 for an HVL of 2.5 mm Al; from NCRP 

(1989, Table B-8). [1]

e. Calculated based on Section 3.5. [3]
Document No. ORAUT-TKBS-0013-3 Revision No. 02 Effective Date: 02/01/2007 Page 15 of 20

3.7 INSTRUCTION GUIDE FOR DOSE RECONSTRUCTORS 

Pantex practice involved maintaining a log of the date and type of medical examination and a 

historical record of the associated radiographs. DOE-provided medical X-ray information should

include a copy or transcription of information from this log. Dose reconstructors should use the list of 

examinations in this log. In the event that the log is not available, dose reconstructors should use the 

default assumptions in Table 3-10 to ensure an assessment of dose favorable to the claimant. 

Table 3-10. Summary of dose reconstruction recommendations. 

Examination Period Default frequency Table

PA chest Before 1/1/1967 Preemployment and annually thereafter Table 3-5

1/1/67–12/31/71 Table 3-6

1/1/72–12/31/81 Table 3-7

1/1/82–12/31/90 Preemployment and every 5 yr thereafter Table 3-7

1/1/91–2004 Table 3-8

Lumbar spine AP Before 1/1/1982 Preemployment, men only Table 3-9

Lumbar spine LAT Preemployment, men only Table 3-9

For actual dose calculations, dose reconstructors should assume a normal distribution with an 

uncertainty of ±30% at the 99% confidence interval. However, to select judgments favorable to 

claimants, dose reconstructors should use only the positive uncertainty and multiply the doses listed 

in Tables 3-5 to 3-9 by a factor of 1.3 to include uncertainty at the 99% confidence level (ORAUT 

2005). 

3.8 ATTRIBUTIONS AND ANNOTATIONS

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

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

reconstruction. These callouts are listed in this section with information provided to identify the source 

and justification for each associated item. Conventional references are provided in the next section 

that link data, quotations, and other information to documents available for review on the ORAU Team 

servers.

[1] Winslow, Robert C., CHP. Dade Moeller & Associates. Senior Health Physicist. August 2006. 

The information provided in the referenced documents for Pantex is adequate to calculate doses 

that could have been received during occupationally required medical X-ray procedures. 

However, there is some uncertainty associated with how measurements to determine the total 

filtration values were performed during this time. Therefore, an approach that is favorable to the 

claimants was used for this TBD. This approach included the calculation of the entrance kerma 

based on information provided in NCRP (1989, Table B.3) for the given kVp and a distance of 

183 cm that was then corrected based on an assumed chest size of 24 cm plus 5 cm between the 

chest and film using the inverse square law for point sources. This value was then corrected 

based on the provided current and exposure times. NCRP (1989, Table B.3) provides information 

based on a total filtration of 2.5 mm Al. This was adjusted to account for the stated 1.5 mm Al 

based on the following formula where t is the thickness of aluminum in millimeters and I and Io are 

the beam intensities with and without the filter, respectively: 

I = Ioe-0.5t
Document No. ORAUT-TKBS-0013-3 Revision No. 02 Effective Date: 02/01/2007 Page 16 of 20

Given the uncertainty associated with measurements to determine the total filtration values, an 

assumption was made to apply DCFs based on 2.5-mm Al HVL in ICRP (1982), which is also 

favorable to claimants.

[2] Winslow, Robert C., CHP. Dade Moeller & Associates. Senior Health Physicist. August 2006. 

Information in site documentation (Huddleston 1995) indicates that an HVL of 4.8 mm Al was in 

place on the X-ray machine that was used starting in 1991. ICRP (1982) and NCRP (1989) 

provide information only up to 4 mm Al HVL. Therefore, an extrapolation was performed for 5-mm 

Al HVL to determine the factors used to convert the entrance kerma to absorbed dose for the 

various organs and the backscatter factor for the entrance skin dose.

[3] Winslow, Robert C., CHP. Dade Moeller & Associates. Senior Health Physicist. August 2006. 

The determination of the absorption factor used in the calculations for the exit skin dose was 

based on an assumed thickness of overlying tissue to exit surface of 23 cm. Before 1991, an HVL 

of 2.5 mm Al was used, and the value was interpolated based on the values provided for 2 and 

3 mm Al. For 1991 to 2004, the value provided for 5-mm Al HVL was used as an assumption 

favorable to claimants. 
Document No. ORAUT-TKBS-0013-3 Revision No. 02 Effective Date: 02/01/2007 Page 17 of 20

REFERENCES

Alexander, R. E., 1972a, “Diagnostic X-ray Machine – Building 12-2 Medical,” memorandum to F. J. 

Kelly (Pantex Medical Director), Mason & Hanger-Silas Mason Company, Pantex Plant, 

Amarillo, Texas, October 17.

Alexander, R. E., 1972b, “X-ray Machine, 12-2 Medical,” memorandum to F. J. Kelly (Pantex Medical 

Director), Mason & Hanger-Silas Mason Company, Pantex Plant, Amarillo, Texas, 

February 10.

Alexander, R. E., 1972c, “X-ray Installation 12-2 Medical,” memorandum to F. J. Kelly (Pantex 

Medical Director), Mason & Hanger-Silas Mason Company, Pantex Plant, Amarillo, Texas, 

July 7.

GE (General Electric Company), 1941, “Technic Chart,” General Electric X-Ray Corporation, 

Milwaukee, Wisconsin, copy obtained from Mason & Hanger-Silas Mason Company, Pantex 

Plant, Amarillo, Texas.

Gidley, M. D., 1970, memorandum to F. J. Kelley (Pantex Medical Director), Mason & Hanger-Silas 

Mason Company, Pantex Plant, Amarillo, Texas, August 19.

Hill, L. G., 1984, “Diagnostic X-ray Machine,” memorandum to F. J. Kelly (Pantex Medical Director), 

Mason & Hanger-Silas Mason Company, Pantex Plant, Amarillo, Texas, May 25.

Huddleston, A. L., 1995, letter to N. Bryson (Mason and Hanger-Silas Mason Company), Texas 

Radiation Physics Associates, Dallas, Texas, December 12.

ICRP (International Commission on Radiological Protection), 1982, Protection of the Worker in 

Diagnostic Radiology, Publication 34, Pergamon Press, Oxford, England.

Ikenberry, T. A. 1983, “Diagnostic X-ray Machine,” memorandum to F. J. Kelly (Pantex Medical 

Director), Mason & Hanger-Silas Mason Company, Pantex Plant, Amarillo, Texas, March 16.

Ikenberry, T. A. 1984, “Diagnostic X-ray Machine, Bldg. 12-2, Medical,” memorandum to F. J. Kelly 

(Pantex Medical Director), Mason & Hanger-Silas Mason Company, Pantex Plant, Amarillo, 

Texas, March 19.

Kelly, T. J., 1990, “Diagnostic X-ray Machine,” memorandum to C. M. Lang (Pantex Medical Director),

Mason & Hanger-Silas Mason Company, Pantex Plant, Amarillo, Texas, June 22.

Mitchell, K. C., 2003, Rhetoric to Reality: A Cold War Context Statement for the Pantex Plant, 1951 – 

1991, BWXT Pantex LLC, Pantex Plant, Amarillo, Texas.

NCRP (National Council on Radiation Protection and Measurements), 1976, Structural Shielding 

Design and Evaluation for Medical Use of X-rays and Gamma Rays of Energies up to 10 MeV, 

Report 49, Bethesda, Maryland.

NCRP (National Council on Radiation Protection and Measurements), 1989, Medical X-Ray Electron 

Beam and Gamma-Ray Protection for Energies Up to 50 MeV (Equipment Design, 

Performance and Use), Report 102, Bethesda, Maryland.
Document No. ORAUT-TKBS-0013-3 Revision No. 02 Effective Date: 02/01/2007 Page 18 of 20

ORAUT (Oak Ridge Associated Universities Team), 2005, Dose Reconstruction from Occupationally 

Related Diagnostic X-Ray Procedures, ORAUT-OTIB-0006, Rev. 03 PC-1, Oak Ridge, 

Tennessee, December 21. 

Pantex, 1967, “X-Ray Procedures,” desk instructions dated April 5 and April 10, initialed by CS, 

Mason & Hanger-Silas Mason Company, Pantex Plant, Amarillo, Texas.

PHS (Public Health Service), 1967, “X-Ray Protection Survey Report, Pantex Medical Department, 

Building 12-36,” Form PHS-4495-3 (Rev. 7-65), Mason & Hanger-Silas Mason Co., Inc., 

Amarillo, Texas, September 26.

PHS (Public Health Service), 1970, “X-Ray Protection Survey Report, Pantex Medical Department, 

Building 12-2,” Form PHS-4495-3 (Rev. 7-65), Mason & Hanger-Silas Mason Co., Inc., 

Amarillo, Texas, August 18.

PHS (Public Health Service), 1993, “Comprehensive Radiation Protection Survey of Mason & HangerPantex Central Health Facility, Bldg 12-2,” Mason & Hanger-Silas, Mason Co., Inc., Amarillo, 

Texas, November 1.
Document No. ORAUT-TKBS-0013-3 Revision No. 02 Effective Date: 02/01/2007 Page 19 of 20

GLOSSARY

absorbed dose

The energy imparted per unit mass by ionizing radiation to matter at a specified point. The 

International System unit of absorbed dose is joules per kilogram. The special name for this 

unit is the gray (Gy). The previously used special unit of absorbed dose, rad, is being 

replaced by the gray (1 rad = 0.01 Gy; 1 Gy = 100 rad).

anterior-posterior (AP)

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

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

entrance kerma

Air kerma in air without backscatter at the point of entry into the body. Also called entrance 

kerma, and formerly called entrance skin exposure. 

entrance skin exposure (ESE)

Air kerma in air without backscatter at the point of entry into the body. The ESE is measured 

in units of Roentgen (R) or kerma (Gy). Also called entrance kerma. 

filtration

The 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. 

half-value layer (HVL)

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

that filters an X-ray beam to reduce the kerma rate by one-half. 

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 ma

lateral (LAT)

ss. 

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

the body to the other.

photofluorography

Historical radiographic technique used for cost- and time-effective production of chest images 

for screening a large number of people in a short period. The X-ray image produced on a 

fluorescent screen was photographed on 4inch by 5inch film. Photofluorography was the 

primary method of screening large populations for tuberculosis before the advent of 

nonradiographic tuberculosis screening methods. Also called mass miniature radiography. 

Not to be confused with fluoroscopy.
Document No. ORAUT-TKBS-0013-3 Revision No. 02 Effective Date: 02/01/2007 Page 20 of 20

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.

radiography

The process of producing images on film (or other media) with radiation. Production of 

radiographs. 

roentgen (R)

Unit of photon (gamma or X-ray) exposure for which the resultant ionization liberates a positive 

or negative charge equal to 2.58 × 10-4 coulombs per kilogram (or 1 electrostatic unit of 

electricity per cubic centimeter) of dry air at 0°C and standard atmospheric pressure. An 

exposure of 1 R is approximately equivalent to an absorbed dose of 1 rad in soft tissue for 

higher energy photons (generally greater than 100 kiloelectron-volts). 

rem

Traditional unit of radiation dose equivalent that indicates the biological damage caused by 

radiation equivalent to that caused by 1 rad of high-penetration X-rays multiplied by a quality 

factor. The average American receives 360 millirem a year from background radiation. The 

sievert is the International System unit; 1 rem equals 0.01 sievert. The word derives from 

roentgen equivalent in man; rem is also the plural.

technique or technic

Combination of X-ray machine settings used to produce radiographs consisting of the applied 

kilovoltage (kVp), tube current (milliamperes), and exposure time (seconds). The last 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 (mAs). Any combination of time and tube 

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

a fixed peak kilovoltage. 

X-ray

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).