ORAU TEAM

Dose Reconstruction

Project for NIOSH

Oak Ridge Associated Universities I Dade Moeller I MJW Technical Services

Page 1 of 20

DOE Review Release 11/30/2012

Document Title:

Nevada Test Site – Occupational Medical 

Dose

Document Number: ORAUT-TKBS-0008-3

Revision: 02

Effective Date: 11/26/2012

Type of Document: TBD

Supersedes: Revision 01

Subject Expert(s): Elyse M. Thomas and Eugene M. Rollins

Approval: Signature on File Approval Date: 11/19/2012

Eugene M. Rollins, Document Owner

Concurrence: Signature on File Concurrence Date: 11/20/2012

John M. Byrne, Objective 1 Manager

Concurrence: Signature on File Concurrence Date: 11/19/2012

Edward F. Maher, Objective 3 Manager

Concurrence: Vickie S. Short Signature on File for Concurrence Date: 11/20/2012

Kate Kimpan, Project Director

Approval: Signature on File Approval Date: 11/26/2012

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-0008-3 Revision No. 02 Effective Date: 11/26/2012 Page 2 of 20

PUBLICATION RECORD

EFFECTIVE 

DATE

REVISION 

NUMBER DESCRIPTION

06/09/2004 00 New technical basis document for the Nevada Test Site –

Occupational Medical Dose. Incorporates internal review and NIOSH 

comments. First approved issue. Initiated by Eugene M. Rollins.

06/22/2007 01 Approved revision initiated to concur with ORAUT-OTIB-0006 

(ORAUT 2005), current data in other TBDs, and to include new legal 

wording in Section 3.1. Constitutes a total rewrite of the document. 

Incorporates formal internal and NIOSH review comments. Adds 

Attributions and Annotations section. This revision results in no 

change to the assigned dose and no PER is required. Training 

required: As determined by the Task Manager. Initiated by Vernon 

E. Shockley.

11/26/2012 02 Revision initiated to incorporate consistency with ORAUT-OTIB0006, ORAUT-OTIB-0079, and new information in the Site Research 

Database (SRDB). Skin doses were developed and added to the 

document for all periods. Incorporates formal internal and NIOSH 

review comments. Constitutes a total rewrite of the document. 

Training required: As determined by the Objective Manager. 

Initiated by Elyse M. Thomas. 
Document No. ORAUT-TKBS-0008-3 Revision No. 02 Effective Date: 11/26/2012 Page 3 of 20

TABLE OF CONTENTS

SECTION TITLE PAGE

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

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

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

3.1.1 Scope........................................................................................................................... 6

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

3.2.1 Photofluorography ........................................................................................................ 6

3.2.2 Chest Radiography, 1951 to 1959 ................................................................................ 7

3.2.3 Chest Radiography, 1960 to 1966 ................................................................................ 8

3.2.4 Chest Radiography, 1967 to 1972 ................................................................................ 8

3.2.5 Chest Radiography, 1973 to 1985 ................................................................................ 9

3.2.6 Chest Radiography, 1986 to 1995 ................................................................................ 9

3.2.7 Chest Radiography, 1996 to Present.......................................................................... 10

3.2.8 Lumbar Spine Radiography, 1960 to 1985.................................................................. 10

3.3 Organ Dose Calculations ....................................................................................................... 11

3.4 Uncertainty............................................................................................................................. 15

3.5 Attributions and Annotations .................................................................................................. 16

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

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

LIST OF TABLES

TABLE TITLE PAGE

3-1 Frequency of chest X-ray screening at NTS............................................................................. 7

3-2 X-ray equipment used at NTS and incident air kerma values ................................................... 8

3-3 Organ dose equivalents from PA and LAT chest X-rays at NTS, 1960 through 1995 ............. 11

3-4 Organ dose equivalents (rem) for lumbar spine projections, 1960 through 1985.................... 12

3-5 Skin dose equivalents from chest projections, 1960 through 1995 ......................................... 13

3-6 Skin dose equivalents from lumbar spine projections, 1960 through 1985 ............................. 14
Document No. ORAUT-TKBS-0008-3 Revision No. 02 Effective Date: 11/26/2012 Page 4 of 20

ACRONYMS AND ABBREVIATIONS

CFR Code of Federal Regulations

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

ESE entrance skin exposure

FDA U.S. Food and Drug Administration

Gy gray

HVL half-value layer

ICRP International Commission on Radiological Protection

IREP Interactive RadioEpidemiological Program

kVp peak kilovoltage

LAT lateral

mA milliampere

mGy milligray

mm millimeter

mR milliroentgen

mrem millirem

NCRP National Council on Radiation Protection and Measurement

NIOSH National Institute for Occupational Safety and Health

NTS Nevada Test Site

ORAU Oak Ridge Associated Universities

PA posterior–anterior

PFG photofluorography

POC probability of causation

SRDB Ref ID Site Research Database Reference Identification (number)

SSD source-to-skin distance

TBD technical basis document

U.S.C. United States Code

§ section or sections
Document No. ORAUT-TKBS-0008-3 Revision No. 02 Effective Date: 11/26/2012 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 historical 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

] 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, 42 C.F.R. Pt. 82) restrict the “performance of duty” 

referred to in 41 U.S.C. § 7384n(b) to nuclear weapons work (NIOSH 2010).

The statute also 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 excludes Naval Nuclear Propulsion Facilities from being covered under the Act, 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 occupational radiation exposures are considered valid for inclusion in a 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 (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

 1 The U.S. Department of Labor (DOL) is ultimately responsible under the EEOICPA for determining the POC.
Document No. ORAUT-TKBS-0008-3 Revision No. 02 Effective Date: 11/26/2012 Page 6 of 20

3.1.1 Purpose

This technical basis document (TBD) documents historical practices at the Nevada Test Site (NTS) 

and provides the basis for organ dose from medical X-ray procedures that were performed for 

occupational health screening at NTS.

3.1.1 Scope

NTS has maintained an occupational health and safety program for its workers over the time of its 

operation, beginning in 1951. Physical examinations of workers typically included chest X-rays to 

screen for disease and monitor the health of its workforce. The organ dose from these X-ray 

procedures depends on the characteristics of the X-ray machine and the techniques that were used. 

Site-specific information about the NTS X-ray screening program, to the extent it is known, was used 

in the development of this document.

Attributions and annotations, indicated by bracketed callouts and used to identify the source, 

justification, or clarification of the associated information, are presented in Section 3.5.

3.2 EXAMINATION TYPES AND FREQUENCIES

Early in NTS operations, it was the responsibility of the employer organizations to ensure that 

personnel who were part of test operations were healthy. A specific frequency or protocol for physical 

examinations was not a requirement early on, but individuals who had not had a physical examination 

within a year of participating in a test were encouraged to have one (Reeves 1957, p. 176).

Starting in about 1960 when X-ray equipment was first installed on the site (Geiger 1960, p. 4), 

physical examinations of workers occurred on a more regular basis (Kathren and Shockley 2004, p. 

12). Chest X-rays were the most commonly performed radiographic screening examination, but some 

workers in certain job classifications appear to have had lumbar spine X-rays to screen for back 

problems. A review of claim file records indicates that chest X-rays were performed annually on 

workers in the early years [1] and less frequently in the later years, perhaps once every 2 to 3 years 

(Kathren and Shockley 2004, p. 10; REECo 1986). Other radiographic examinations of NTS workers 

that might have occurred were necessitated by illness or injury and were not part of the employee 

occupational health screening process. Eventually, NTS subcontracted the X-ray examinations out to 

offsite, noncovered facilities in Las Vegas (DeMarre 2012a), and the X-ray machine at Mercury was 

used only for accidents.

In the 1960s, there was another medical X-ray machine at the Nuclear Rocket Development Station 

complex. However, because of its remote location, it was not likely to have been used for routine 

physicals but might have been used for accidents in the field (DeMarre 2012a,c).

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

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

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

the X-rays that were performed for screening as listed in the claim file records or, in the absence of 

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

3.2.1 Photofluorography

No evidence that photofluorography (PFG) was used at NTS has been found either in the historical 

documentation or in the claim file records. If a dose reconstructor finds evidence of PFG in the claim 

file records, dose should be assigned using the values in ORAUT-OTIB-0006, Dose Reconstruction 
Document No. ORAUT-TKBS-0008-3 Revision No. 02 Effective Date: 11/26/2012 Page 7 of 20

from Occupational Medical X-Ray Procedures (ORAUT 2011a). In the absence of evidence in the 

claim file records, or in the absence of records, no dose from PFG should be assigned.

Table 3-1. Frequency of chest X-ray screening at NTS.

Perioda Worker category Frequency

Examination and 

projections

1951–1959 All workers (offsite)b Preemployment, annualc, and 

termination

PA chest

1960–1966 All workers Preemployment, annuald, and 

termination

PA chest

1967–1972 All workers Preemployment and termination PA chest 

Respirator wearerse Annual PA chest 

All other workers Every 2 yrb

1973–1985 All workers (offsite)f Preemployment and termination PA and LAT chestf

Respirator wearerse Annual PA and LAT chestf

All other workers Every 2 yrb

1986–1988g All workers (offsite)f Preemployment (no termination) PA chest

Culinary workers in Mercury:

18–39 yr old Annual PA chest

>40 yr old Annual PA, plus LAT chest 

every 5 yr

Smokers Annual PA, plus LAT chest 

every 2 yr

Miners, shaker plant workers, 

asbestos workers 

Annual PA, plus LAT every 5 yr

All other workers in Mercury:

19–20 yr old None

21–39 yr old Every 5 yr PA chest

>40 yr old Every 5 yr PA and LAT chest

>40 yr old (smoker) Every 2 yr PA and LAT chest

1989–present 

(offsite)f

Same as for 1986–1988

(offsite)f

Same as for 1986–1988

(offsite)f

Same as for 1986–1988

(offsite)f

a. Dates are approximate.

b. Kathren and Shockley (2004, p. 7).

c. Reeves (1957).

d. Based on a review of claim file records.

e. REECo (ca. 1975).

f. DeMarre (2012a).

g. REECo (1986).

3.2.2 Chest Radiography, 1951 to 1959

Chest X-rays before 1960 were taken off the site at noncovered contractor facilities, probably 

physicians’ offices in Las Vegas (Kathren and Shockley 2004, p. 7). This statement is supported by 

the historical information in Reeves (1957). Reeves lists the facilities available at NTS, and only a first 

aid station is mentioned (Reeves 1957 p. 9). A medical service was to have been retained with a 

skeleton crew should an evacuation be necessary after a detonation (Reeves 1957 p. 72), and that 

future plans called for a physician and nurse to be on duty during test operations (Reeves 1957 p. 73). 

There was a military dispensary on site for military personnel, but others (i.e. civilians) were to be sent 

to Las Vegas hospitals for treatment (Reeves 1957 p. 185-186). There is no evidence of X-ray 

equipment on-site at NTS before 1960. A review of claim file records with employment start dates 

before 1960 reveals that none have X-ray records with the “Medical Department, Mercury, Nevada” 

stamp on them, while six have evidence of having been performed off-site in Las Vegas [2]. 
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According to ORAUT-OTIB-0079, Guidance on Assigning Occupational X-ray Dose Under EEOICPA 

for X-rays Administered Off-Site (ORAUT 2011b), dose from X-rays taken off the site at noncovered 

facilities cannot be included in dose reconstruction.

3.2.3 Chest Radiography, 1960 to 1966

During this period, all workers received a preemployment, annual, and termination posterior-anterior 

(PA) chest examination [1].

In 1960, a Standard X-ray machine was installed on the site at NTS (Geiger 1960, p. 4). A log of 

X-rays that were taken with this machine lists the technique factors for a PA chest as 72 to 75 kVp, 

200 mA, and 1/20 second. Geiger (1960, pp. 4, 7) mentions that the collimating cones for the 

machine had been ordered but had not yet arrived on the date he performed a survey of the machine.

In 1955, the National Council on Radiation Protection and Measurements (NCRP) recommendation 

for minimum filtration for diagnostic X-ray units called for 2-mm Al equivalent filtration for new 

machines (NBS 1955). Assuming the Standard X-ray machine met this recommendation, the halfvalue layer (HVL) for the chest X-rays taken at 75 kVp would be 2.0 mm Al (NCRP 1997, p. 98).

The incident air kerma value for this period is 2.28 cGy based on the average air kerma rates in 

NCRP Report 102 (1997, p. 99), the technique factors and HVL information specific to NTS that are 

mentioned above, and the methodology in ORAUT-OTIB-0006 (ORAUT 2011a) for calculating 

incident air kerma. An almost identical value was obtained using the pelvis measurement data 

contained in Geiger after correction for use for chest X-rays (1960, pp. 9), or the information in DHEW 

(1970, p. 160). Poor collimation is assumed for this period, meaning that additional organs were 

included in the primary beam than would otherwise be included when an X-ray beam is properly 

collimated. The additional organs that are included in the primary beam of a poorly collimated beam 

are described in ORAUT-OTIB-0006. Incident air kerma values and HVL information is summarized 

in Table 3-2.

Table 3-2. X-ray equipment used at NTS and incident air kerma values.

Period X-ray machine

kVp

(kV)

Assumed HVL

(mm Al)

Incident air kerma (cGy)

PA chest LAT chest

1951–1959 Offsite (a) (a) (a) (a)

1960–1966 Standard X-ray 75b 2.0b 0.0228b (c)

1967–1972 GE Unknown 3.0d 0.040e (c)

1973–1985 Unknown Unknown 3.0d 0.040e 0.100d

1986–1988 GE 110f 3.0f 0.007f 0.018f

1989–present Offsite (a) (a) (a) (a)

a. Dose from X-rays that were taken at noncovered offsite facilities is not eligible for inclusion under EEOICPA.

b. Based on technique factors and measurement data in Geiger (1960).

c. Not performed for screening during this period.

d. Based on ORAUT-TKBS-0008-3, Rev. 01.

e. Based on ORAUT-TKBS-0008-3, Rev. 01, Goldman and Beech (1979), and ORAUT (2009).

f. Stevenson (1988).

Dose reconstructors should assign dose for the X-rays that are listed in the claim file records. In the 

absence of records, dose reconstructors should assign dose according to the frequency in Table 3-1.

3.2.4 Chest Radiography, 1967 to 1972

During this period, all workers received a preemployment and a termination PA chest examination. In 

addition, respirator wearers received an annual PA chest examination (REECo ca. 1975), while all 

other workers received a PA chest every 2 years (Kathren and Shockley 2004, p. 7).
Document No. ORAUT-TKBS-0008-3 Revision No. 02 Effective Date: 11/26/2012 Page 9 of 20

Photographs from the NTS archive from 1967 and 1970 show a General Electric (GE) machine with 

an adjustable collimator (rectangular beam) (DeMarre 2012a). Other records that were provided by 

NTS show that a GE X-ray machine was inspected by the U.S. Food and Drug Administration (FDA)

in 1988 (Stevenson 1988). It is not certain if this is the same GE machine that was in place in 1967 

(DeMarre 2012b).

No documentation has been found to date of surveys that were performed at NTS during this period.

Data from the National X-ray Exposure Studies of 1970 report an entrance skin exposure (ESE) of 44 

mR for the PA chest in facilities nationwide representing all types of equipment (Goldman and Beech, 

1979, pg. 44). A later national study reports the mean of measured ESEs from all types of facilities 

and equipment as 23 mR (Wochos, 1979, pg. 130). Technique factor data from GE equipment used 

at the Idaho National Laboratory (INL) for 1967-1985 results in an ESE of 52 mR for a PA chest 

(ORAUT 2009, pp. 8-9), while technique factor information from GE equipment at Pinellas results in 

an ESE of 32 mR for 1972-1987 (ORAUT 2011c). Since all of these values bracket the 40 mR ESE 

value used in Rev. 01 of the NTS Medical TBD, and several of them are lower, there does not seem 

to be solid evidence for a change at this time. Incident air kerma values and HVL information are 

summarized in Table 3-2.

Dose reconstructors should assign dose for the X-rays that are listed in the claim file records. In the 

absence of records, dose reconstructors should assign dose according to the frequency in Table 3-1.

3.2.5 Chest Radiography, 1973 to 1985

During this period, workers received preemployment physicals, including X-rays, at contracted, 

noncovered facilities in Las Vegas (DeMarre 2012a,c). Steinberg Radiographic Service was one such 

contractor. These contractors might also have provided the periodic and termination chest X-rays if 

the worker was in Las Vegas. The location where the X-rays were taken was sometimes, but not 

always recorded in the submitted claim file records [1]. Lateral chest X-ray projections appear in the 

claim file records for this period (see Table 3-1). 

Dose reconstructors should review the location information that might be recorded on the X-ray 

records. Without records, or specific location information, dose reconstructors should assume that the 

preemployment chest X-ray was taken off the site at a noncovered facility and should assign dose for 

the remaining X-rays in the claim file records (because those might have been performed at NTS). In 

the absence of records, dose reconstructors should assign dose according to the frequency in 

Table 3-1.

No documentation has been found to date of surveys that were performed at NTS during this period. 

Data from the National X-ray Exposure Studies of 1970 report an ESE of 44 mR for the PA chest in 

facilities nationwide representing all types of equipment (Goldman and Beech, 1979, pg. 44). A later 

national study reports the mean of measured ESEs from all types of facilities and equipment as 23 

mR (Wochos, 1979, pg. 130). Technique factor data from GE equipment used at INL for 1967-1985 

results in an ESE of 52 mrad for a PA chest (ORAUT 2009, pp. 8-9), while technique factor 

information from GE equipment at Pinellas results in an ESE of 32 mR for 1972-1987 (ORAUT 

2011c). Since all of these values bracket the 40 mR ESE value used in Rev. 01 of the NTS Medical 

TBD, and several of them are lower, there does not seem to be solid evidence for a change at this 

time. Incident air kerma values and HVL information is summarized in Table 3-2.

3.2.6 Chest Radiography, 1986 to 1995

There are two important pieces of evidence that were provided by NTS for this period. A 1986 

document describes the X-ray screening protocols, including specific information about the PA and 

LAT chest projections to be taken and when (REECo 1986). It is clear from this document that the 
Document No. ORAUT-TKBS-0008-3 Revision No. 02 Effective Date: 11/26/2012 Page 10 of 20

frequency of X-ray screening was decreasing for some groups of workers. However, the 

recommendations for other groups of workers, such as culinary workers, miners, shaker plant 

workers, and asbestos workers, remained on an annual chest X-ray screening schedule. The details 

of this document are summarized in Table 3-1.

The other important piece of evidence that was provided by NTS for this period is a letter from the 

FDA providing the results of a 1988 survey of the X-ray equipment at NTS. It mentions that such 

surveys were performed every 2 years (Stevenson 1988). The survey of a GE machine states that 

the measured entrance skin exposure (ESE) for a PA chest examination was 8 mR at 110 kVp. The 

letter does not mention that the machine’s filtration was noncompliant, so the HVL can be assumed to 

be at least 3.1 mm Al at 110 kVp (NCRP 1997, p. 98). A rounded value of 3.0 mm Al is used for ease 

in selection of dose conversion factors for dose reconstruction.

During this period, workers continued to receive preemployment physicals at contracted, noncovered 

facilities in Las Vegas (DeMarre 2012a,c). Steinberg Radiographic Service was one such contractor 

(DeMarre 2012c). These contractors might also have provided the periodic and termination chest 

X-rays if the worker was in Las Vegas. The location where the X-rays were taken was sometimes, but 

not always recorded in the submitted claim file records [1]. Lateral chest X-ray projections appear in 

the claim file records for this period (see Table 3-1). 

Dose reconstructors should review the location information that might be recorded on the X-ray 

records. Without records, or specific location information, dose reconstructors should assume that the 

preemployment chest X-ray was taken off the site at a noncovered facility and should assign dose for 

the remaining X-rays in the claim file records (because these might have been performed at NTS). In 

the absence of records, dose reconstructors should assign dose according to the frequency in 

Table 3-1.

The organ doses for this period were determined starting with the 8 mR ESE that was measured by 

FDA with correction of this value to incident air kerma as described in ORAUT-OTIB-0006 (ORAUT 

2011a) and assuming an HVL of 3.0 mm Al. Incident air kerma values and HVL information is 

summarized in Table 3-2.

3.2.7 Chest Radiography, 1996 to Present

NTS sold and removed its X-ray equipment in 1996 (Moon, 2012). After this date, all radiographic 

services were contracted out to a variety of offsite, noncovered facilities in Las Vegas such as the 

previously mentioned Steinberg Radiographic Services (DeMarre 2012c). All X-rays of NTS workers 

after 2000 have been performed at Centennial Hospital (DeMarre 2012a). According to ORAUTOTIB-0079 (ORAUT 2011b), dose from X-rays taken off the site at noncovered facilities cannot be 

included in dose reconstruction, so dose reconstructors should not include dose from X-ray 

procedures of NTS workers after 1995.

3.2.8 Lumbar Spine Radiography, 1960 to 1985

No evidence has been found in historical records that lumbar spine X-rays were taken for screening. 

A detailed screening protocol for 1986 and later makes no mention of lumbar spine X-rays for 

screening (REECo 1986). However, some of the claim file records show that lumbar spine X-rays 

were taken on some workers. Because the claim file records do not usually specify the reason for the 

X-ray, it cannot be determined from them if the lumbar spine X-rays were taken for screening or as a 

result of an injury, symptom, or complaint. Dose reconstructors should, therefore, include dose from 

lumbar spine X-rays if they were taken before 1986 and when it might make sense to do so from the 

information in the claim file records (e.g., the worker’s job description implies heavy lifting). If any 

information in the claim file records implies that the lumbar spine X-rays were taken as a result of an 
Document No. ORAUT-TKBS-0008-3 Revision No. 02 Effective Date: 11/26/2012 Page 11 of 20

injury, accident, or back pain, then dose from lumbar spine X-rays should not be assigned. In the 

absence of records, dose from lumbar spine X-rays should not be assigned.

Doses for lumbar spine X-rays [PA and lateral (LAT) projections] are from ORAUT-OTIB-0006 

(ORAUT 2011a).

3.3 ORGAN DOSE CALCULATIONS

Organ dose equivalents for PA and LAT chest X-rays were based on the method that is described in 

ORAUT-OTIB-0006 (ORAUT 2011a) and dose conversion factors in International Commission on 

Radiological Protection (ICRP) Publication 34 (ICRP 1982). ICRP (1982) provides tables of average 

absorbed dose (in milligray) 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). The tables list the basic dose conversion factors (DCFs) for converting air kerma to organ 

dose. 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-OTIB-0006 or are footnoted in the organ dose tables.

Table 3-3 lists the organ dose equivalents for PA and LAT chest X-rays for 1960 through 1988. 

Table 3-4 lists the organ dose equivalents for AP and LAT lumbar spine X-rays for 1960 through 

1985. Skin dose equivalents for all skin areas were determined according to the method that is 

described in ORAUT-OTIB-0006 (ORAUT 2011a) and listed in Tables 3-5 and 3-6.

Table 3-3. Organ dose equivalents (rem) from PA and LAT chest X-rays at NTS, 1960 through 1995.

Organ

Chest

projection

1960–1966

Standard X-ray 

machine

1967–1972

GE machinea

1973–1985

Equipment

unknowna

1986–1995

GE machineb

Thyroid PA 3.44E-03c 1.84E-03 1.84E-03 3.22E-04

LAT (d) (d) 1.33E-02 2.33E-03

Eye/brain PA 4.79E-04e 1.84E-03 1.84E-03 3.22E-04

LAT (d) (d) 1.33E-02 2.33E-03

Ovaries PA 2.62E-03f 7.20E-05 7.20E-05 1.26E-05

LAT (d) (d) 9.00E-05 1.58E-05

Liver/gall bladder/ 

spleen/pancreas

PA 8.09E-03 2.14E-02 2.14E-02 3.75E-03

LAT (d) (d) 2.67E-02 4.67E-03

Urinary bladder/ 

prostate

PA 2.62E-03 7.20E-05 7.20E-05 1.26E-05

LAT (d) (d) 9.00E-05 1.58E-05

Colon/rectum PA 2.62E-03 7.20E-05 7.20E-05 1.26E-05

LAT (d) (d) 9.00E-05 1.58E-05

Testes PA 1.30E-04f 4.00E-07 4.00E-07 7.00E-08

LAT (d) (d) 1.00E-05 1.75E-06

Lungs (male) PA 7.64E-03 1.98E-02 1.98E-02 3.47E-03

LAT (d) (d) 2.36E-02 4.13E-03

Lungs (female) PA 8.09E-03 2.14E-02 2.14E-02 3.75E-03

LAT (d) (d) 2.67E-02 4.67E-03

Thymus PA 8.09E-03 2.14E-02 2.14E-02 3.75E-03

LAT (d) (d) 2.67E-02 4.67E-03

Esophagus PA 8.09E-03 2.14E-02 2.14E-02 3.75E-03

LAT (d) (d) 2.67E-02 4.67E-03

Stomach PA 8.09E-03 2.14E-02 2.14E-02 3.75E-03

LAT (d) (d) 2.67E-02 4.67E-03

Bone surfaces PA 8.09E-03 2.14E-02 2.14E-02 3.75E-03

LAT (d) (d) 2.67E-02 4.67E-03

Remainder PA 8.09E-03 2.14E-02 2.14E-02 3.75E-03

LAT (d) (d) 2.67E-02 4.67E-03
Document No. ORAUT-TKBS-0008-3 Revision No. 02 Effective Date: 11/26/2012 Page 12 of 20

Organ

Chest

projection

1960–1966

Standard X-ray 

machine

1967–1972

GE machinea

1973–1985

Equipment

unknowna

1986–1995

GE machineb

Breast PA 7.30E-04 2.76E-03 2.76E-03 4.83E-04

LAT (d) (d) 2.87E-02 5.02E-03

Uterus PA 2.35E-03f 9.20E-05 9.20E-05 1.61E-05

LAT (d) (d) 9.00E-05 1.58E-05

Bone marrow (male) PA 1.57E-03 4.68E-03 4.68E-03 8.19E-04

LAT (d) (d) 4.80E-03 8.40E-04

Bone marrow (female) PA 1.44E-03 4.48E-03 4.48E-03 7.84E-04

LAT (d) (d) 3.80E-03 6.65E-04

Entrance sking PA 3.01E-02h 5.60E-02h 5.60E-02h 9.80E-03h

LAT (d) (d) 1.40E-01h 2.45E-02h

a. ORAUT-TKBS-0008-3, Rev. 01.

b. Stevenson 1988.

c. DCF for AP cervical spine, corrected with depth dose factor of 0.2 (ORAUT 2011a).

d. Not performed for screening in this period.

e. DCF for PA chest (ORAUT 2011a).

f. DCF for PA abdomen (ORAUT 2011a).

g. Skin dose equivalents for all areas of skin are provided in Table 3-5.

h. Calculated using backscatter factor of 1.32 for HVL of 2.0 mm Al, 1.35 for HVL of 2.5 mm, and 1.4 for HVL of 

3.0 mm Al from NCRP Report 102 (NCRP 1997, Table B.8).

Table 3-4. Organ dose equivalents (rem) for lumbar spine projections, 1960 

through 1985.

a

Organ Projection 1960–1970 1971–1985

Thyroid AP 2.88E-04 2.73E-04

LAT 3.79E-05 3.48E-05

Eye/brain AP 2.88E-04 2.73E-04

LAT 3.79E-05 3.48E-05

Ovaries AP 5.60E-01 1.97E-01

LAT 7.10E-01 1.64E-01

Urinary/bladder/prostate AP 2.30E-01 1.97E-01

LAT 1.17E-01 1.64E-01

Colon/rectum AP 2.30E-01 1.97E-01

LAT 1.17E-01 1.64E-01

Testes AP 2.70E-02 3.82E-03

LAT 5.60E-02 2.78E-03

Lungs (male) AP 8.93E-02 7.19E-02

LAT 3.79E-02 4.87E-02

Lungs (female) AP 8.93E-02 7.19E-02

LAT 3.79E-02 4.87E-02

Thymus AP 8.93E-02 7.19E-02

LAT 3.79E-02 4.87E-02

Esophagus AP 8.93E-02 7.19E-02

LAT 3.79E-02 4.87E-02

Stomach AP 2.30E-01 1.97E-01

LAT 1.17E-01 1.64E-01

Bone surface AP 2.30E-01 1.97E-01

LAT 1.17E-01 1.64E-01

Liver/gall bladder/spleen/pancreas AP 2.30E-01 1.97E-01

LAT 1.17E-01 1.64E-01

Remainder organs AP 2.30E-01 1.97E-01

LAT 1.17E-01 1.64E-01

Breast AP 4.78E-03 9.56E-04

LAT 7.58E-03 2.07E-03

Uterus AP 3.12E-01 2.61E-01
Document No. ORAUT-TKBS-0008-3 Revision No. 02 Effective Date: 11/26/2012 Page 13 of 20

Organ Projection 1960–1970 1971–1985

LAT 7.58E-02 1.08E-01

Bone marrow (male) AP 3.46E-02 3.37E-02

LAT 5.69E-02 7.66E-02

Bone marrow (female) AP 3.46E-02 3.37E-02

LAT 5.69E-02 7.66E-02

Entrance skinb AP 1.90E+00 1.23E+00

LAT 5.00E+00 4.70E+00

a. ORAUT-OTIB-0006 (ORAUT 2011a).

b. Skin dose equivalents for all areas of skin are provided in Table 3-6.

Table 3-5. Skin dose equivalents (rem) from chest projections, 1960 through 1995.

a

Area of skin

PA chest

1960–1966

PA chest

1967–1972

PA chest

1973–1985

LAT chest

1973–1985

PA chest

1986–

1988

LAT chest

1986–1995

Right front shoulder 7.E-04 1.4E-03 1.4E-03 1.40E-01 2.E-04 2.45E-02

Right back shoulder 3.01E-02 5.60E-02 5.60E-02 1.40E-01 9.8E-03 2.45E-02

Left front shoulder 7.E-04 1.4E-03 1.4E-03 7.E-04 2.E-04 1.E-04

Left back shoulder 3.01E-02 5.60E-02 5.60E-02 7.E-04 9.8E-03 1.E-04

Right upper arm to elbow 3.01E-02 5.6E-03 5.6E-03 1.40E-01 1.E-03 2.45E-02

Left upper arm to elbow 3.01E-02 5.6E-03 5.6E-03 7.E-04 1.E-03 1.E-04

Left hand 3.01E-02 5.6E-03 5.6E-03 1.40E-02 1.E-03 2.5E-03

Right hand 3.01E-02 5.6E-03 5.6E-03 1.40E-02 1.E-03 2.5E-03

Left elbow, forearm, wrist 3.01E-02 5.6E-03 5.6E-03 1.40E-02 1.E-03 2.5E-03

Right elbow, forearm, wrist 3.01E-02 5.6E-03 5.6E-03 1.40E-02 1.E-03 2.5E-03

Right side of head 

including temple and ear

3.0E-03 5.6E-03 5.6E-03 1.40E-02 1.E-03 2.5E-03

Left side of head including 

temple and ear

3.0E-03 5.6E-03 5.6E-03 1.40E-02 1.E-03 2.5E-03

Front left thigh 7.E-06 2.E-05 2.E-05 2.E-05 3.E-06 4.E-06

Back left thigh 7.E-06 2.E-05 2.E-05 2.E-05 3.E-06 4.E-06

Front right thigh 7.E-06 2.E-05 2.E-05 2.E-05 3.E-06 4.E-06

Back right thigh 7.E-06 2.E-05 2.E-05 2.E-05 3.E-06 4.E-06

Left knee and below 3.E-06 7.E-06 7.E-06 8.E-06 1.E-06 1.E-06

Right knee and below 3.E-06 7.E-06 7.E-06 8.E-06 1.E-06 1.E-06

Left side of face 5.E-04 1.8E-03 1.8E-03 1.40E-02 3.E-04 2.5E-03

Right side of face 5.E-04 1.8E-03 1.8E-03 1.40E-02 3.E-04 2.5E-03

Left side of neck 3.01E-02 5.6E-03 5.6E-03 1.40E-02 1.E-03 2.5E-03

Right side of neck 3.01E-02 5.6E-03 5.6E-03 1.40E-02 1.E-03 2.5E-03

Back of head 3.0E-03 5.6E-03 5.6E-03 1.40E-02 1.E-03 2.5E-03

Front of neck 5.E-04 1.8E-03 1.8E-03 1.40E-02 3.E-04 2.5E-03

Back of neck 3.01E-02 5.6E-03 5.6E-03 1.40E-02 1.E-03 2.5E-03

Front torso: base of neck 

to end of sternum

7.E-04

1.4E-03 1.4E-03

2.67E-02 2.E-04 4.7E-03

Front torso: end of 

sternum to lowest rib

7.E-04

1.4E-03 1.4E-03

2.67E-02 2.E-04 4.7E-03

Front torso: lowest rib to 

iliac crest

7.E-04

1.E-04 1.E-04

2.7E-03 2.E-05 5.E-04

Front torso: iliac crest to 

pubis

7.E-05

1.E-04 1.E-04

2.7E-03 2.E-05 5.E-04

Back torso: base of neck 

to mid-back

3.01E-02 5.60E-02 5.60E-02 2.67E-02 9.8E-03 4.7E-03

Back torso: mid-back to 

lowest rib

3.01E-02 5.60E-02 5.60E-02 2.67E-02 9.8E-03 4.7E-03

Back torso: lowest rib to 

iliac crest

3.01E-02 5.6E-03 5.6E-03 2.7E-03 1.E-03 5.E-04
Document No. ORAUT-TKBS-0008-3 Revision No. 02 Effective Date: 11/26/2012 Page 14 of 20

Area of skin

PA chest

1960–1966

PA chest

1967–1972

PA chest

1973–1985

LAT chest

1973–1985

PA chest

1986–

1988

LAT chest

1986–1995

Back torso: buttocks (Iliac 

crest and below)

3.0E-03 5.6E-03 5.6E-03 2.7E-03 1.E-03 5.E-04

Right torso: base of neck 

to end of sternum

3.01E-02 5.60E-02 5.60E-02 1.40E-01 9.8E-03 2.45E-02

Right torso: end of 

sternum to lowest rib

3.01E-02 5.60E-02 5.60E-02 1.40E-01 9.8E-03 2.45E-02

Right torso: lowest rib to 

iliac crest

3.01E-02 5.6E-03 5.6E-03 1.40E-02 1.E-03 2.5E-03

Right torso: iliac crest to 

pubis (right hip)

3.0E-03 5.6E-03 5.6E-03 1.40E-02 1.E-03 2.5E-03

Left torso: base of neck to 

end of sternum

3.01E-02 5.60E-02 5.60E-02 7.E-04 9.8E-03 1.E-04

Left torso: end of sternum 

to lowest rib

3.01E-02 5.60E-02 5.60E-02 7.E-04 9.8E-03 1.E-04

Left torso: lowest rib to 

iliac crest

3.01E-02 5.6E-03 5.6E-03 7.E-05 1.E-03 1.E-05

Left torso: iliac crest to 

pubis (left hip)

3.0E-03 5.6E-03 5.6E-03 7.E-05 1.E-03 1.E-05

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

Table 3-6. Skin dose equivalents (rem) from lumbar spine projections, 1960 through 1985.

a

Area of skin

AP lumbar spine 

1960–1970

LAT lumbar spine 

1960–1970

AP lumbar spine 

1971–1985

LAT lumbar spine 

1971–1985

Right front shoulder 1.90E-01 5.00E-01 1.23E-01 4.70E-01

Right back shoulder 3.6E-03 5.00E-01 2.7E-03 4.70E-01

Left front shoulder 1.90E-01 1.9E-03 1.23E-01 2.1E-03

Left back shoulder 3.6E-03 1.9E-03 2.7E-03 2.1E-03

Right upper arm to elbow 1.90E-01 5.00E-01 1.23E-01 4.70E-01

Left upper arm to elbow 1.90E-01 1.9E-03 1.23E-01 2.1E-03

Left hand 1.90E+00 1.9E-03 1.23E-01 2.1E-03

Right hand 1.90E+00 5.00E-01 1.23E-01 4.70E-01

Left elbow, forearm, wrist 1.90E+00 1.9E-03 1.23E-01 2.1E-03

Right elbow, forearm, wrist 1.90E+00 5.00E-01 1.23E-01 4.70E-01

Right side of head 

including temple and ear

3.E-04 4.E-05 3.E-04 3.E-05

Left side of head including 

temple and ear

3.E-04 4.E-05 3.E-04 3.E-05

Front left thigh 1.90E-01 1.9E-03 1.23E-01 2.1E-03

Back left thigh 3.6E-03 1.9E-03 2.7E-03 2.1E-03

Front right thigh 1.90E-01 5.00E-01 1.23E-01 4.70E-01

Back right thigh 3.6E-03 5.00E-01 2.7E-03 4.70E-01

Left knee and below 4.E-04 4.E-04 3.E-04 5.E-04

Right knee and below 4.E-04 4.E-04 3.E-04 5.E-04

Left side of face 3.E-04 4.E-05 3.E-04 3.E-05

Right side of face 3.E-04 4.E-05 3.E-04 3.E-05

Left side of neck 3.E-04 4.E-05 3.E-04 3.E-05

Right side of neck 3.E-04 4.E-05 3.E-04 3.E-05

Back of head 3.E-04 4.E-05 3.E-04 3.E-05

Front of neck 3.E-04 4.E-05 3.E-04 3.E-05

Back of neck 3.E-04 4.E-05 3.E-04 3.E-05

Front torso: base of neck 

to end of sternum

1.90E-01 3.79E-02 1.23E-01 4.87E-02
Document No. ORAUT-TKBS-0008-3 Revision No. 02 Effective Date: 11/26/2012 Page 15 of 20

Area of skin

AP lumbar spine 

1960–1970

LAT lumbar spine 

1960–1970

AP lumbar spine 

1971–1985

LAT lumbar spine 

1971–1985

Front torso: end of 

sternum to lowest rib

1.90E+00 3.79E-02 1.23E+00 4.87E-02

Front torso: lowest rib to 

iliac crest

1.90E+00 3.79E-02 1.23E+00 4.87E-02

Front torso: iliac crest to 

pubis

1.90E+00 3.79E-02 1.23E+00 4.87E-02

Back torso: base of neck 

to mid-back

3.6E-03 3.79E-02 2.7E-03 4.87E-02

Back torso: mid-back to 

lowest rib

3.64E-02 3.79E-02 2.68E-02 4.87E-02

Back torso: lowest rib to 

iliac crest

3.64E-02 3.79E-02 2.68E-02 4.87E-02

Back torso: buttocks (Iliac 

crest and below)

3.64E-02 3.79E-02 2.68E-02 4.87E-02

Right torso: base of neck 

to end of sternum

1.90E-01 5.00E-01 1.23E-01 4.70E-01

Right torso: end of 

sternum to lowest rib

1.90E+00 5.00E+00 1.23E+00 4.70E+00

Right torso: lowest rib to 

iliac crest

1.90E+00 5.00E+00 1.23E+00 4.70E+00

Right torso: iliac crest to 

pubis (right hip)

1.90E+00 5.00E+00 1.23E+00 4.70E+00

Left torso: base of neck to 

end of sternum

1.90E-01 1.9E-03 1.23E-01 2.1E-03

Left torso: end of sternum 

to lowest rib

1.90E+00 1.90E-02 1.23E+00 2.06E-02

Left torso: lowest rib to 

iliac crest

1.90E+00 1.90E-02 1.23E+00 2.06E-02

Left torso: iliac crest to 

pubis (left hip)

1.90E+00 1.90E-02 1.23E+00 2.06E-02

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

3.4 UNCERTAINTY

ORAUT-OTIB-0006 (ORAUT 2011a) lists the major sources of uncertainty in X-ray output intensity 

and subsequent effect on dose to the worker. The five sources of uncertainty are:

1. X-ray beam measurement error (±2%),

2. Variation in peak kilovoltage (±9%),

3. Variation in X-ray beam current (±5%),

4. Variation in exposure time (±25%), and

5. Variation in source-to-skin distance (SSD) as a result of worker size (±10%).

The 10% uncertainty in output intensity as a result of worker size was based on an inverse square 

correction of output intensity changes from differences from the standard chest thickness of ±7.5 cm.

These uncertainties are assumed to be random; therefore, the combined statistical uncertainty was 

calculated as the square root of the sum of the squares of all the uncertainties, which is ±28.9%. 

Rounding this up to ±30% provides an adequate and suitably conservative indication of uncertainty. 

Therefore, for a derived dose equivalent to an individual organ, a total combined standard uncertainty

of ±30% can be assumed. Dose reconstructors should, therefore, input the organ dose equivalent as 

the mean of a normal distribution with a standard uncertainty of ±30%.
Document No. ORAUT-TKBS-0008-3 Revision No. 02 Effective Date: 11/26/2012 Page 16 of 20

3.5 ATTRIBUTIONS AND ANNOTATIONS

Where appropriate in this document, 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 here in the Attributions and Annotations section, with information to identify 

the source and justification for each associated item. Conventional References, which are provided in 

the next section of this document, link data, quotations, and other information to documents available 

for review on the Project's Site Research Database (SRDB).

[1] Thomas, E. Oak Ridge Associated Universities (ORAU) Team. Principal Medical Dosimetrist. 

March 2012.

A random sample of claim file records was reviewed to assess the types and frequency of 

screening X-rays that were performed at NTS.

[2] Thomas, E. Oak Ridge Associated Universities (ORAU) Team. Principal Medical Dosimetrist. 

June 2012. A complete review of X-ray records (N=119) in claims with start dates before 

1960 (N= 474) show that only 8 had X-rays before 1960, 6 of these showed that the X-rays 

were taken off-site, 2 were uncertain as to where they were taken because NTS extracted the 

information, but none appear to have been taken at Mercury; none had the “Medical 

Department, Mercury, Nevada” stamp on them.
Document No. ORAUT-TKBS-0008-3 Revision No. 02 Effective Date: 11/26/2012 Page 17 of 20

REFERENCES

DeMarre, M., 2012a, “RE: Nevada Test Site Request (NTS FY12-001),” e-mail to D. G. Morris (Oak 

Ridge Associated Universities Team), National Security Technologies, Las Vegas, Nevada, 

March 13. [SRDB Ref ID: 112131, p. 1]

DeMarre, M., 2012b, “RE: Additional Questions (X-Ray Issue at NTS),” e-mail to D. G. Morris (Oak 

Ridge Associated Universities Team), National Security Technologies, Las Vegas, Nevada, 

March 15. [SRDB Ref ID: 112140]

DeMarre, M., 2012c, “RE: Additional X-Ray Related Questions (NTS) Related to Request NTS-FY12-

001,” e-mail to D. G. Morris (Oak Ridge Associated Universities Team), National Security 

Technologies, Las Vegas, Nevada, March 14. [SRDB Ref ID: 112248]

DHEW (U.S. Department of Health, Education, and Welfare), 1970, Radiological Health Handbook, 

Revised Edition, Public Health Service, Rockville, Maryland, January. [SRDB Ref ID: 75017]

Kathren, R. L., and V. E. Shockley, 2004, “Personal Communications with ME DeMarre re Medical XRays at NTS,” memorandum to file, Oak Ridge Associated Universities, Oak Ridge, 

Tennessee, August 30. [SRDB Ref ID: 13367]

Geiger, E. L., A. N. Tschaeche, and F. W. Wilcox, 1960, Nevada Test Site Medical X-Ray Equipment, 

A Preliminary Hazards Evaluation, RRS-60-10, Reynolds Electrical & Engineering Company, 

Las Vegas, Nevada, May. [SRDB Ref ID: 13365]

Goldman, L.W., and Beech, S., 1979, Analysis of Retakes: Understanding, Managing, and Using an 

Analysis of Retakes Program for Quality Assurance, DHEW (U.S. Department of Health, 

Education, and Welfare) Publication (FDA) 79-8097, Public Health Service, Rockville, 

Maryland, August. [SRDB Ref ID: 38739]

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

Diagnostic Radiology, Publication 34, Pergamon Press, Oxford, England. [SRDB Ref ID: 

76680]

Moon, J. C., 2012, “Request X-ray Surveillance/Testing Information” email to M. DeMarre (National 

Testing Archive), National Security Technologies, Las Vegas, Nevada, March 15. [SRDB Ref 

ID: 112245]

NBS (National Bureau of Standards), 1955, X-Ray Protection, Recommendations of the National 

Committee on Radiation Protection, Handbook 60, U.S. Department of Commerce, 

Washington, D.C., December 1. [SRDB Ref ID: 73173]

NCRP (National Council on Radiation Protection and Measurements), 1997, Medical X-Ray, Electron 

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

Performance and Use), Report 102, Bethesda, Maryland. [SRDB Ref ID: 32467]

NIOSH (National Institute for Occupational Safety and Health), 2010, Radiation Exposures Covered 

for Dose Reconstructions Under Part B of the Energy Employees Occupational Illness 

Compensation Program Act, DCAS-IG-003, Rev. 1, Division of Compensation Analysis and 

Support, Cincinnati, Ohio, October 5.
Document No. ORAUT-TKBS-0008-3 Revision No. 02 Effective Date: 11/26/2012 Page 18 of 20

ORAUT (Oak Ridge Associated Universities Team), 2009, INL-ANL-W Occupational Medical Dose, 

ORAUT-TKBS-0007-3, Rev. 02, Oak Ridge Associated Universities, Oak Ridge, Tennessee, 

December 21.

ORAUT (Oak Ridge Associated Universities Team), 2011a, Dose Reconstruction from Occupational 

Medical X-Ray Procedures, ORAUT-OTIB-0006, Rev. 04, Oak Ridge Associated Universities, 

Oak Ridge, Tennessee, June 20.

ORAUT (Oak Ridge Associated Universities Team), 2011b, Guidance on Assigning Occupational 

X-ray Dose Under EEOICPA for X-rays Administered Off-Site, ORAUT-OTIB-0079, Rev. 00, 

Oak Ridge, Tennessee, January 3.

ORAUT (Oak Ridge Associated Universities Team), 2011c, Pinellas Plan – Occupational Medical 

Dose, ORAUT-TKBS-0029, Rev. 01, Oak Ridge Associated Universities, Oak Ridge, 

Tennessee, October 13.

REECo (Reynolds Electrical & Engineering Company), ca. 1975, Respirator Users Medical 

Examination Requirements, Las Vegas, Nevada. [SRDB Ref ID: 16744]

REECo (Reynolds Electrical & Engineering Company), 1986, Description of the REECo Integrated 

Medical Program, Las Vegas, Nevada. [SRDB Ref ID: 112131, pp. 7–9]

Reeves, J. E., 1957, “Test Manager’s Standard Operating Procedure for the Nevada Test 

Organization,” memorandum to Distribution, U.S. Atomic Energy Commission, Albuquerque 

Operations Office, Albuquerque, New Mexico, March 15. [SRDB Ref ID: 7972]

Stevenson, D. A., 1988, untitled letter to S. Anson (Reynolds Electrical & Engineering Company), U.S. 

Department of Health and Human Services, Food and Drug Administration, San Francisco, 

California, August 31. [SRDB Ref ID: 112131, p. 5]

Wochos, J.F., Detorie, N.A., and Cameron, J.R., 1979, Patient Exposure from Diagnostic X-rays: An 

Analysis of 1972-1975 NEXT Data, Health Physics 36:127-134. [SRDB Ref ID: 91506]
Document No. ORAUT-TKBS-0008-3 Revision No. 02 Effective Date: 11/26/2012 Page 19 of 20

GLOSSARY

entrance skin exposure (ESE)

Exposure in air, measured in roentgens, at the point where an X-ray beam enters the skin 

surface (without backscatter).

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.

gray (Gy)

The special name for the SI unit of absorbed dose, kerma, and specific energy imparted equal 

to one (1) joule per kilogram (J/kg) (1 Gy = 1 J/kg = 100 rad).

half-value layer (HVL)

Thickness of a specified substance usually specified in millimeters of aluminum, which, when 

introduced into the path of a given beam of radiation, reduces the kerma rate by one-half.

Interactive RadioEpidemiological Program (IREP)

Computer program that uses a person’s calculated annual organ doses and other information 

(e.g., gender, age at diagnosis, and age at exposure) to calculate the probability of causation 

of a specific cancer for a given pattern and level of radiation exposure.

International Commission on Radiological Protection (ICRP)

An independent international scientific body, established to advance for the public benefit the 

science of radiological protection, in particular by providing recommendations and guidance on 

all aspects of protection against ionizing radiation.

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 form structures 

or terrain. The word derives from kinetic energy released per unit mass.

National Council on Radiation Protection and Measurements (NCRP)

Private U. S. public service organization chartered by the U.S. Congress to formulate and 

disseminate information, guidance, and recommendations on radiation protection and 

measurements.

organ dose

Dose to a given organ from an X-ray procedure.

photofluorography (PFG)

Historical radiographic technique used for 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 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.
Document No. ORAUT-TKBS-0008-3 Revision No. 02 Effective Date: 11/26/2012 Page 20 of 20

photon

Basic unit of electromagnetic radiation. Photons are massless “packages” of light energy that

range from low-energy microwave photons to high-energy gamma rays. Photons have 

energies between 10 and 100 kiloelectron-volts. Generally regarded as a discrete particle 

having zero rest mass, no electric charge, and an indefinitely long lifetime. The entire range of

electromagnetic radiation that extends in frequency from 1023 cycles per second (hertz) to 0

hertz.

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.

preemployment X-ray

An X-ray, usually of the chest, taken before hire or assignment to a specific job. The purpose 

of preplacement X-rays was to screen for active disease, such as tuberculosis.

probability of causation (POC)

For purposes of dose reconstruction for the Energy Employees Occupational Illness

Compensation Program Act, the percent likelihood, at the 99th percentile, that a worker 

incurred a particular cancer from occupational exposure to radiation.

radiograph

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

matter. Some of the rays (photons) can pass through parts of an item, while more opaque

parts partially or completely absorb them and thus cast a shadow on the film. In the context of

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

disease.

source-to-skin distance (SSD)

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

distance varies with the size of the person being radiographed.

technique factors

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

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.

termination X-ray

X-ray, usually of the chest, taken when an employee separates from the company.

tube current

Average electrical current measured in milliamperes flowing from the cathode to the anode of

an X-ray tube during operation of the tube.

X-ray

(1) Ionizing electromagnetic radiation of external nuclear origin, or (2) a radiograph.

X-ray tube

Evacuated electronic tube in which electrons accelerated by an applied voltage to strike an 

anode or target and produce X-rays.