Page 1 of 17

DOE Review Release 08/28/2019

Rocky Flats Plant – Occupational Medical 

Dose

ORAUT-TKBS-0011-3 Rev. 03 

Effective Date: 08/19/2019

Supersedes: Revision 02 

Subject Expert(s): Robert C. Winslow

Document Owner 

Approval: Signature on File

Mutty M. Sharfi, Document Owner

Approval Date: 08/07/2019

Concurrence: Signature on File

Christopher M. Tornes, Objective 1 Representative

Concurrence Date: 08/07/2019

Concurrence: Signature on FIle

Scott R. Siebert, Objective 3 Manager

Concurrence Date: 08/07/2019

Concurrence: Signature on File

Scott R. Siebert, Project Director Representative

Concurrence Date: 08/08/2019

Approval: Signature on File

Timothy D. Taulbee, Associate Director for Science

Approval Date: 08/19/2019

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

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

New Total Rewrite Revision Page Change
Document No. ORAUT-TKBS-0011-3 Revision No. 03 Effective Date: 08/19/2019 Page 2 of 17

 

PUBLICATION RECORD

EFFECTIVE 

DATE

REVISION 

NUMBER DESCRIPTION

02/09/2004 00 New Technical Basis Document for the Rocky Flats Plant –

Occupational Medical Dose. First approved issue. Initiated by 

Robert Meyer.

04/23/2007 01 Approved Revision 01 initiated to revise Table 3.4.2-2 (now Table 

3-6), text, and dose estimate tables to be consistent with ORAUTOTIB-0006 Rev 03 PC-1. Revised Table 3.2-1 (now Table 3-1) and 

text to specify the inclusion of termination X-rays for the period of 

1952-1986. Revised Table 3.4.1-2 (now Table 3-5) per commitment 

tracking form dated 02/06/2006. Revised to include attribution 

information per ORAU direction. The Worker Outreach comment 

from CT-0203 was addressed. Worker outreach comment from the 

June 23, 2004, meeting of the United Steelworkers of America Local 

8031 and Rocky Flats Security Officers Local Union 1 was addressed 

in Section 3.1. Incorporates formal internal and NIOSH review 

comments. Constitutes a total rewrite of document. This revision 

results in an increase in assigned dose and a PER is required. 

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

Robert Meyer.

06/27/2017 02 Revision initiated to update occupational medical X-ray doses for 

PFG, AP and LAT lumbar spine, and AP chest examinations. The 

AP chest examination dose update is specific to those performed 

starting June 11, 2001. Skin dose guidance and doses are also 

included in Attachment 1 of this revision based on information 

presented in ORAUT-OTIB-0006 Rev 04. Additional information 

regarding the availability of X-ray inventory sheets starting around 

February 2009 is included. CLL uncertainty parameters have been 

included as well. Updated Table A-2 to separate skin dose values for 

PA chest examinations between 1971 and 2001 into two time periods 

(1971-1984 and 1985-2001). Corrected transcription errors in Table 

A-1 of 8 skin doses for LAT exams performed prior through 1970 to 

correctly reflect values listed in ORAUT-OTIB-0006 Rev 04. 

Incorporates formal internal review comments. No changes occurred 

as a result of formal NIOSH review. Constitutes a total rewrite of the 

document. Training required: As determined by the Objective 

Manager. Initiated by Brian P. Martin.

08/19/2019 03 Revision initiated to update occupational medical X-ray doses for AP 

and LAT lumbar spine in Table 3-7; for PFG, AP, and LAT chest in 

Table A-1; and AP and LAT lumbar and PA chest in Table A-2 based 

on information presented in ORAUT-OTIB-0006, Revision 05. 

Table 3-7 column header dates corrected to read “1951–1970” and 

“1971–1974”. Incorporates formal internal and NIOSH review 

comments. Constitutes a total rewrite of the document. Training 

required: As determined by the Objective Manager. Initiated by 

Brian P. Martin. 
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TABLE OF CONTENTS

SECTION TITLE PAGE

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

3.1 Introduction ................................................................................................................................. 6

3.1.1 Purpose........................................................................................................................... 7

3.1.2 Scope.............................................................................................................................. 7

3.1.3 Special Exposure Cohort ................................................................................................ 7

3.2 Background................................................................................................................................. 8

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

3.4 Organ Dose Estimates................................................................................................................ 9

3.4.1 Parameters and Estimation Method................................................................................ 9

3.4.2 Organ Dose Estimates ..................................................................................................10

3.5 Uncertainties.............................................................................................................................11

3.6 Examination Frequency ............................................................................................................12

3.7 Attributions and Annotations .....................................................................................................13

References ...........................................................................................................................................14

Glossary................................................................................................................................................15

ATTACHMENT A SKIN VIEW GUIDANCE AND DOSE TABLES .................................................17

LIST OF TABLES

TABLE TITLE PAGE

3-1 Description of X-ray equipment at RFP ...................................................................................... 8

3-2 Equipment settings and ratings................................................................................................... 8

3-3 Organ dose estimates for PA chest beginning June 11, 2001, to March 31, 2005...................11

3-4 IREP dose distributions and statistical parameters for the dose to the B lymphocytes ............11

3-5 Default X-ray examination frequencies for all workers..............................................................12

A-1 Skin dose guidance and doses PA chest, June 11, 2001, to March 31, 2005..........................17
Document No. ORAUT-TKBS-0011-3 Revision No. 03 Effective Date: 08/19/2019 Page 4 of 17

ACRONYMS AND ABBREVIATIONS

AP anterior-posterior

AWE atomic weapons employer

cGy centigray

CLL chronic lymphocytic leukemia

cm centimeter

DCF dose conversion factor

DOE U.S. Department of Energy

DOL U.S. Department of Labor

EEOICPA Energy Employees Occupational Illness Compensation Program Act of 2000

ENSD entrance skin dose

EXSD exit skin dose

Gy gray

HVL half-value layer

ICRP International Commission on Radiological Protection

in. inch

IREP Interactive RadioEpidemiological Program

keV kilo-electron volt

kV kilovolt

kVp kilovolts-peak

LAT lateral

m meter

mA milliampere

mAs milliampere-second

mGy milligray

mm millimeter

mrem millirem

NIOSH National Institute for Occupational Safety and Health

ORAU Oak Ridge Associated Universities

PA posterior-anterior

PER program evaluation report

PFG photofluorography

R roentgen

RFP Rocky Flats Plant

RSD remote skin dose

s second

SEC Special Exposure Cohort

SID source-to-image distance
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SRDB Ref ID Site Research Database Reference Identification (number)

SSD source-to-skin distance

Sv sievert

TBD technical basis document

U.S.C. United States Code

§ section or sections
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3.1 INTRODUCTION

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

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

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

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

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

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

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

of the individual work required for each dose reconstruction.

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

dose reconstructions for covered employees (NIOSH 2010):

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

conventional structures

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

reasons
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3.1.1 Purpose

This technical basis document (TBD) describes the methods for estimating absorbed dose from 

medical X-ray exposures to Rocky Flats Plant (RFP) workers. All information regarding X-ray 

examination types/frequencies, machine specific parameters, and relevant doses presented in this 

document are particular to RFP. Dose calculations are based on information presented in ORAUTOTIB-0006, Dose Reconstruction from Occupational Medical X-Ray Procedures (ORAUT 2018). 

Where data are unavailable, assumptions have been made that are favorable to claimants and in line 

with current guidance (ORAUT 2018). 

3.1.2 Scope

Section 3.2 provides background. Section 3.3 provides information on equipment and techniques 

used at RFP including assumptions necessitated by lack of protocol, measurement, or records data. 

Section 3.4 provides organ dose estimates for RFP beginning on June 11, 2001. Section 3.5

documents uncertainties. Section 3.6 describes X-ray examination frequency at RFP. Attributions 

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

clarification of the associated information, are presented in Section 3.7. 

3.1.3 Special Exposure Cohort

The Secretary of the U.S. Department of Health and Human Services has designated the following 

class of RFP workers as an addition to the SEC (Sebelius 2013):

All employees of the Department of Energy, its predecessor agencies, and their 

contractors and subcontractors who worked at the Rocky Flats Plant in Golden, 

Colorado, from April 1, 1952 through December 31, 1983, for a number of work days 

aggregating at least 250 work days, occurring either solely under this employment or in 

combination with work days within the parameters established for one or more other 

classes of employees included in the Special Exposure Cohort.

NIOSH has determined that doses to unmonitored RFP workers from neptunium, thorium, and 233U 

(and its associated 232U and 228Th progeny) cannot be reconstructed from April 1, 1952, through 

December 31, 1983, inclusive (NIOSH 2013). The class includes all workers during the SEC period.

Based on the inability to reconstruct unmonitored doses from 1952 through 1983, as described above, 

all dose reconstructions for monitored workers during the SEC period are considered partial dose 

reconstructions. If monitoring data are available for workers in the SEC, dose is to be assigned as 

appropriate based on that data. Unmonitored neutron doses before 1967 have been identified as 

infeasible and therefore cannot be bounded. It is not feasible to reconstruct unmonitored neutron 

doses, in a bounding manner, before 1967; therefore, this TBD does not provide dose reconstruction 

guidance for unmonitored neutron doses before 1967. For all other years, external dose records 

and/or an unmonitored external dose reconstruction approach are provided. However, such dose 

reconstructions are still considered partial dose reconstructions because of the determination that 

exposure to neptunium, thorium, and 233U (and its associated 232U and 228Th progeny) during the SEC 

period cannot be bounded (NIOSH 2013). 

The principal sources of external radiation doses, including medical X-ray dose, for members of the 

proposed class were evaluated in the NIOSH RFP SEC-00030 Evaluation Report (ER). In SEC00030, NIOSH concluded that all external dose, except neutrons, could be estimated with sufficient 

accuracy.
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3.2 BACKGROUND

As part of the requirements for employment at RFP, entrance, exit, and periodic physical 

examinations were performed on all employees. These physical examinations included radiographic 

examinations of the lungs and, for some employees, the lumbar spine as shown in reviews of claimant 

records. Diagnostic medical X-rays administered in conjunction with routine or special physical 

examinations and required for employment are occupational exposures (NIOSH 2007). Only medical 

exposures that were required as a condition of employment are included; diagnostic and therapeutic 

procedures that were not required for employment are excluded (e.g., exposures that were received in 

the treatment of work-related injuries).

Additional information on the assessment and calculation of dose from occupational medical X-rays is 

given in ORAUT (2018).

3.3 EQUIPMENT AND TECHNIQUES

It was determined after a review of information about specific machines and machine settings used at 

RFP that it is not possible to calculate machine specific doses for equipment in use before June 11, 

2001. Therefore, the information needed to fully develop site-specific organ doses from occupational 

medical X-rays (i.e., the type of equipment, technique factors, and machine calibrations) is not fully 

known for years before 2001. Some information has been found regarding equipment types and 

ratings. Tables 3-1 and 3-2 summarize known information about equipment and techniques. The 

available data has been used in conjunction with default data (ORAUT 2018), where necessary, to 

provide estimates of potential exposure

Efforts will continue to find related information for RFP. However, until more accurate records are 

found, these assumptions provide estimates for medical X-ray exposure that are favorable to 

claimants.

Table 3-1. Description of X-ray equipment at RFP. 

Period Classification Equipment Source

07/1953–08/30/1976 Type IV Keleket ORAUT 2003a

09/01/1976–05/28/1987 Type III Generator unknown; Victoreen R Meter; 

Bureau of Radiological Health test stand; 

X-ray timer; aluminum filter set; light meter

ORAUT 2003a

05/29/1987–03/06/2001 Type II Eureka XMA tube; generator unknown ORAUT 2003a

06/11/2001–03/31/2005 Type I Hologic/BXT202W ORAUT 2003a

Table 3-2. Equipment settings and ratings (ORAUT 2003a). 

Period Machine View

Current 

(mA)

Voltage 

(kVp)

Exposure time 

(s)

1952–1974 Type IVb Lumbar APa 200 140 Unknown

1952–1974 Type IVb Lumbar LATa 200 140 Unknown

07/1953–08/30/1976 Type IVb Chest PA 200 140 Unknown

09/01/1976–05/28/1987 Type IIIb Chest PA Unknown 80 Unknown

05/29/1987–03/06/2001 Type IIb Chest PA 360 130 Unknown

06/11/2001–03/31/2005 Type Ic Chest PA 300 125 0.013

a. Assume performed from 1952 to 1974. 

b. Maximum machine ratings (ORAUT 2003a); data not used to calculate doses, but are presented for informational 

purposes.

c. The maximum kVp, mA, and exposure time are listed as provided by Senior X-ray Technician (Various 2003–2005). 

This results in a maximum mAs of 3.9.

The onsite medical office ceased operation in mid-March of 2005 and the X-ray unit was sold the 

following month (Various 2003–2005). As such, it is assumed all occupational medical doses for RFP 
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employees ended that same month, and therefore, no occupational medical doses should be 

assigned for employment starting April 1, 2005. Historical review of claimant records indicate lumbar 

spine examinations were discontinued in 1975, and therefore, are only assumed for 1952 through 

1974.

Based on X-ray inventory records provided after February 2009, photofluorography (PFG) 

examinations were performed at RFP. A note in the available documentation indicates that the 

fluoroscope was removed from the plant in 1968 (ORAUT 2003a). There is not enough information 

about the machine and settings to derive site-specific doses; therefore, default PFG doses from 

ORAUT (2018) are assigned.

As no information was available regarding examination film/projection sizes, default assumptions 

(ORAUT 2018) are used for all RFP medical X-ray examinations.

3.4 ORGAN DOSE ESTIMATES

This section provides organ dose estimates. Section 3.4.1 describes the method used to estimate 

the doses post-June 11, 2001, when there is enough information to calculate site-specific organ 

doses. As discussed in Section 3.3, not all equipment or settings information about what was in use 

at RFP before 2001 has been located. Therefore, site-specific organ doses cannot be calculated for 

the time period prior to June 11, 2001, and default dose values are assigned from ORAUT (2018). 

Section 3.4.2 will discuss the assignment of organ dose for both periods: prior to June 11, 2001 when 

default OTIB-0006 doses are assigned and post-June 11, 2001 when site-specific organ doses are 

assigned.

3.4.1 Parameters and Estimation Method

The ICRP (1982) guidance uses the following parameters to estimate air kerma and absorbed dose:

1. Source-to-image distance (SID) in centimeters,

2. Total filtration (millimeters of aluminum),

3. Estimate of person thickness for AP and LAT projections, and

4. Machine settings (mAs, kVp, film size, and single- or three-phase).

Because measured air kerma data are unavailable for the RFP, air kerma rates are estimated from 

Figure A.1 in ICRP Publication 34, Protection of the Patient in Diagnostic Radiology (ICRP 1982), 

using average voltage from Table 3-2 and total filtration. SID, filtration, and chest thickness 

parameters are based on information presented in ORAUT (2018) while machine settings are specific 

to Hologic X-ray unit on site with a 125 kVp and 300 mA technique (Various 2003–2005). The 

calculated HVL of 3.57 mm Al at 80 kVp was rounded to 4.0 mm Al as a claimant favorable 

assumption (Various 2003–2005). These values differ from previously assumed machine parameters 

as recently obtained site specific information (Various 2003–2005) indicates these are the maximum 

settings that were used for the Hologic X-ray unit.

Since Figure A.1 is for single-phase machines, the estimate from this graph is multiplied by 1.8 to 

account for the fact that the RFP machine is three-phase. Therefore, the air kerma in air rate in units 

of mGy per mAs estimated from Figure A.1 is 0.090 mGy per mAs. This rate is then used to estimate 

the air kerma at 1m by multiplying the air kerma in air rate by the current and exposure time for the 

RFP machine. Next, the air kerma at the source-to-skin distance (SSD) is calculated. The SSD
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assumed for the PA chest projection that was performed at RFP is 154 cm and is the default SSD for 

this projection from ORAUT (2018). This yields an air kerma of 0.266 mGy at the SSD.

Tables A.2 through A.9 of ICRP (1982) are then used to estimate organ dose directly. The tables list 

organ doses in milligray normalized to an air kerma of 1 Gy in air at the skin, as a function of 

half-value layers (HVLs) in millimeters of aluminum. Entrance skin dose (ENSD) was calculated by 

multiplying the air kerma at SSD by the appropriate backscatter factor from Table B-8 of National 

Council on Radiation Protection and Measurements Report 102 (NCRP 1989). The backscatter factor

used for these RFP-specific calculations is 1.42 and was chosen based on the HVL and field size 

assumptions for Rocky Flats Plant. 

The ICRP tables that were used to estimate absorbed dose do not include all organs in the Interactive 

RadioEpidemiological Program (IREP). For those organs in IREP but not specifically identified in the 

ICRP tables, the dose conversion coefficient that is anatomically closest to the IREP-specified organs 

can be used to estimate dose. ORAUT (2018) provides the analogues for IREP organs and specific 

organ analogues according to International Classification of Diseases code in Table 5-1 and 

Attachment A of the document. Dose conversion factors used for RFP are consistent with those 

found in Table B-3 of ORAUT (2018). 

3.4.2 Organ Dose Estimates

At this time, there is insufficient information to calculate site-specific organ doses for chest X-rays 

before 2001, all lumbar spine X-rays, and all PFG examinations at RFP. The organ doses that are 

presented in this document will be revised if additional site-specific information is found that allows for 

a more refined calculation of organ doses.

The use of proxy data for the earlier periods is based on the idea that RFP, like other DOE sites, used 

the standard radiological procedure of the time [1]. Organ dose estimates for occupational X-rays 

from June 11, 2001, to March 31, 2005 are provided in Table 3-4. 

All doses and dose views for RFP X-ray examinations before June 11, 2001, should be assigned 

based on those presented in ORAUT (2018). PFG was used at RFP, but no information about 

protocol has been found. Lacking information about PFG at RFP, default dose estimates from 

ORAUT (2018) are assigned.

Doses starting June 11, 2001, to March 31, 2005 are based on known machine settings and 

information such as HVL supplied by former medical workers and quality assurance documents

(Various 2003–2005). Skin doses for RFP X-ray examinations from June 11, 2001 and later were 

determined based on the guidance in ORAUT-PROC-0061, Occupational Medical X-Ray Dose 

Reconstruction for DOE Sites (ORAUT 2017), and Table B-8 of ORAUT (2018). Skin dose guidance 

for this time period is provided in Attachment A.

Entrance skin dose (ENSD), exit skin dose (EXSD), and remote skin dose (RSD) are all described in 

Section 6.0 through 6.4 of ORAUT (2018). This information regarding calculation of dose was used to 

calculate the doses in Attachment A for post June 11, 2001 examinations. In calculating EXSD, an 

Absorption Factor of 32.66 was assumed based on information presented Table B-7 of NCRP (1989) 

while an average depth dose of 0.193 was used in calculating RSD based on Table B-8 of NCRP 

(1989). Both factors are based on assumed patient thickness of 24 cm. The average depth dose is 

calculated at the midpoint of the body, at a depth of 12 cm.

Where information is unavailable or not known regarding the energy spectra of examinations, values 

should be conservatively assumed to be in the 30- to 250-keV photon range in accordance with 

ORAUT (2018). 
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The tissue at risk for chronic lymphocytic leukemia is the B-lymphocytes. The dose to the 

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

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

1982). Table 3-4 provides dose distributions and statistical parameters for input into IREP for 

determining dose to the B-lymphocytes as provided in Attachment B of ORAUT (2014). 

Table 3-3. Organ dose estimates for PA chest beginning June 11, 2001, to March 31, 2005 (Various 

2003–2005). 

HVL = 4.0 mm Al, air kerma at skin = 0.266 mGya

Organ mGy rem

Thyroid 2.08E–02 2.08E–03

Eye/brain 2.08E–02 2.08E–03

Ovaries 1.39E–03 1.39E–04

Liver/gall bladder/spleen 1.80E–01 1.80E–02

Urinary bladder 1.39E–03 1.39E–04

Colon/rectum 1.39E–03 1.39E–04

Testes 2.66E–06 2.66E–07

Lung (male) 1.67E–01 1.67E–02

Lung (female) 1.80E–01 1.80E–02

Thymus 1.80E–01 1.80E–02

Esophagus 1.80E–01 1.80E–02

Stomach 1.80E–01 1.80E–02

Bone surfaces 1.80E–01 1.80E–02

Remainder 1.80E–01 1.80E–02

Female breast 3.09E–02 3.09E–03

Uterus 1.39E–03 1.39E–04

Bone marrow (male) 4.74E–02 4.74E–03

Bone marrow (female) 4.58E–02 4.58E–03

Entrance skin 3.78E–01 3.78E–02

a. HVL determined rounded up based on calculation of 

total filtration 3.57 mm Al (Various 2003-2005). 

Table 3-4. IREP dose distributions and statistical parameters for the dose to the B-lymphocytes.

Projection Year Distribution Parameters 1, 2, and 3

PFG 1952–1968 Use OTIB-0006 PFG Use OTIB-0006 PFG

PA chest 1952–1970 Use OTIB-0006 through 1970 Use OTIB-0006 through 1970

AP LS 1952–1970 Use OTIB-0006 through 1970 Use OTIB-0006 through 1970

LAT LS 1952–1970 Use OTIB-0006 through 1970 Use OTIB-0006 through 1970

AP LS 1971–1974 Use OTIB-0006 after 1970 Use OTIB-0006 after 1970 

LAT LS 1971–1974 Use OTIB-0006 after 1970 Use OTIB-0006 after 1970

PA chest 1971–1985 Use OTIB-0006 1971–1985 Use OTIB-0006 1971–1985

PA chest 1986–June 10, 

2001

Use OTIB-0006 1986–present Use OTIB-0006 1986–present

PA chest June 11, 2001–

March 31, 2005

Weibull3 2.124902, 0.003815, and –7.1779E–07

3.5 UNCERTAINTIES

Although many factors can introduce uncertainty and error into X-ray dose estimates, five factors 

contribute the most: measurement error, variation in peak kilovoltage, variation in beam current, 

variation in exposure time, and SSD. Film speed, use of screens, or use of grids do not affect the 

beam output intensity. The lack of records for these measurements for most years at RFP introduces 

a large uncertainty into the dose estimates that cannot be readily quantified, although there is no 

apparent reason to believe that practices at RFP were different from those at other facilities or from 
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recommended standards of the medical community at the time. Therefore, use of default estimates 

and reliance on information from other DOE sites when site-specific information was unavailable is 

likely to closely approximate X-ray performance at RFP. For the pre-June 11, 2001, time period, 

when default doses are assigned, default uncertainty assumptions will be used (normal distribution, 

standard deviation of 30%), as discussed in ORAUT (2018). Because the approach used for 

calculating the RFP-specific doses for the time period post-June 11, 2001, relied on the approaches 

and defaults from OTIB-0006, the default uncertainty from ORAUT (2018) is also assumed (normal 

distribution, standard deviations of 30%).

3.6 EXAMINATION FREQUENCY 

Site-specific information indicates the first X-ray unit was not on site until July of 1953. Since 

construction was started in 1952 and employees were present, assume X-ray examinations started in 

1952 (claimant-favorable assumption). The onsite medical office ceased operation in mid-March of 

2005 and the X-ray unit was sold the following month (Various 2003–2005). As such, no occupational 

medical doses should be assigned for employment after March 30, 2005.

The frequency of X-ray examinations varied significantly for RFP workers. Before approximately 

1986, many production workers received single-view chest X-rays on a nearly annual basis. A 

protocol for frequency of a single posterior-anterior (PA) view chest X-ray as a function of job category 

was not fully established until approximately 1986. Therefore, beginning in 1986, the frequency of 

routine chest X-rays varied widely depending on job description (EG&G 1991). The RFP default 

frequency assumption is an annual chest projection, with PFG being used prior to 1969 and PA chest 

after 1969.

Between 1952 and 1974, it is assumed all workers received spinal X-rays during their initial 

employment (prehire) medical examination, as this was typical across the complex. Termination 

chest X-rays are assumed for the period from 1952 to 2005 because they were common at other DOE 

sites.

Beginning with DR claims received in February of 2009, the RFP records group committed to 

providing an X-ray “inventory” with new EEOICPA claim responses. X-ray records provided to NIOSH 

before February 2009 might be incomplete. For claims initially received prior to February 2009, dose 

reconstructors should request an X-ray inventory spreadsheet when a best estimate is required. The 

RFP records group reviews documented films and provides a list (i.e., inventory) of all X-ray 

examinations. Film records are provided in a spreadsheet, which contains the claimant’s name, 

NIOSH ID number, examination type, date of examination, and number of X-rays taken. The dose 

reconstructor should review all relevant claim information in order to determine if X-ray examinations 

provided in the film inventory are those required for employment and not related to work related 

injuries. If no X-ray records are located in this review, RFP does not provide an inventory, but 

completes the records request form with this information. Justification for including, or not including, 

assumed annual X-ray examinations should be provided by the dose reconstructor.

In the absence of an RFP-provided X-ray film inventory or claim-specific information, assume the RFP 

default examination frequencies given in Table 3-5.

Table 3-5. Default X-ray examination frequencies for all workers.

a

Period Frequency View

1952–1968 Annual and termination Chest (PFG)

1952–1974 Once Lumbar (AP and LAT)

1969–2005 Annual and termination Chest (PA)

a. Default frequencies provide overestimating assumptions for the assignment of RFP 

occupational medical dose in the absence of an RFP X-ray inventory collected after 

January 2009. 
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3.7 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] Lopez, Theresa. Oak Ridge Associated Universities (ORAU) Team. Senior Toxicologist. July 

2006.

In the absence of data or protocols, assumptions that needed to be made were favorable to 

claimants.
Document No. ORAUT-TKBS-0011-3 Revision No. 03 Effective Date: 08/19/2019 Page 14 of 17

 

REFERENCES 

EG&G (Edgerton, Germeshausen, and Grier), 1991, Occupational Health Medical Examination 

Criteria, Appendix I, Rocky Flats Plant, Golden, Colorado, November. [SRDB Ref ID: 71527]

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

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

32466]

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, June 30. [SRDB Ref ID: 32467]

NIOSH (National Institute for Occupational Safety and Health), 2007, External Dose Reconstruction 

Implementation Guideline, OCAS-IG-001, Rev. 3, Office of Compensation Analysis and 

Support, Cincinnati, Ohio, November 21. [SRDB Ref ID: 38864]

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. [SRDB Ref ID: 88929]

NIOSH (National Institute for Occupational Safety and Health), 2013, SEC Petition Evaluation Report, 

Petition SEC-00192, Rev. 1, Division of Compensation Analysis and Support, Cincinnati, Ohio, 

September 30. [SRDB Ref ID: 132777]

ORAUT (Oak Ridge Associated Universities Team), 2003a, “Location of Rocky Flats Medical X-Ray 

Documents,” memorandum to file, Oak Ridge, Tennessee, October 21. [SRDB Ref ID: 

12408]

ORAUT (Oak Ridge Associated Universities Team), 2003b, “2001 X-Ray Machine Settings for RFP,”

documented communication, Oak Ridge, Tennessee, July 30. [SRDB Ref ID: 25014]

ORAUT (Oak Ridge Associated Universities Team), 2014, Medical Dose to the B-Lymphocytes, 

ORAUT-RPRT-0064, Rev. 00, Oak Ridge, Tennessee, June 3. [SRDB Ref ID: 132772]

ORAUT (Oak Ridge Associated Universities Team), 2017, Occupational Medical X-Ray Dose 

Reconstruction for DOE Sites, ORAUT-PROC-0061, Rev. 04, Oak Ridge, Tennessee, June 6. 

[SRDB Ref ID: 166910] 

ORAUT (Oak Ridge Associated Universities Team), 2018, Dose Reconstruction from Occupational 

Medical X-Ray Procedures, ORAUT-OTIB-0006, Rev. 05, Oak Ridge, Tennessee, August 13. 

[SRDB Ref ID: 172596] 

Sebelius, K., 2013, HHS Designation of Additional Members of the Special Exposure Cohort Under 

the Energy Employees Occupational Illness Compensation Program Act of 2000 Designating a 

Class of Employees from Rocky Flats Plant, Golden, Colorado, U.S. Department of Health and 

Human Services, Office of the Secretary, Washington, D.C., December 12. [SRDB Ref ID: 

166855]

Various authors, 2003–2005, collection of information on medical X-ray equipment, pp. 2, 5, and

14. [SRDB Ref ID: 176613]
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GLOSSARY

exposure

In this document, measure of the ionization produced by X- and gamma-ray photons in air in 

units of roentgens.

gray (Gy)

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

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

100 rads.

kerma

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

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

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

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

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

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

lumbosacral spine

Region of the spine including the five lumbar vertebrae (lower back) and the five fused sacral 

vertebrae (posterior wall of the pelvis).

radiation

Subatomic particles and electromagnetic rays (photons) with kinetic energy that interact with 

matter through various mechanisms that involve energy transfer.

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 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.

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 degrees Celsius and standard atmospheric 

pressure. An exposure of 1 roentgen is approximately equivalent to an absorbed dose of 

1 rad in soft tissue for higher energy photons (generally greater than 100 kiloelectron-volts).

shallow dose equivalent

Dose equivalent in units of rem or sievert at a depth of 0.07 millimeters (7 milligrams per 

square centimeter) in tissue equal to the sum of the penetrating and nonpenetrating doses.

skin dose

See shallow dose equivalent.

sievert (Sv)

International System unit for dose equivalent, which indicates the biological damage caused 

by radiation. The unit is the radiation value in gray (equal to 1 joule per kilogram) multiplied by 

a weighting factor for the type of radiation and a weighting factor for the tissue; 1 sievert 

equals 100 rem.
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X-ray radiation

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

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

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

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

SKIN VIEW GUIDANCE AND DOSE TABLES

Table A-1. Skin dose guidance and doses PA chest (rem), June 11, 2001, to March 31, 2005.

a

Area of skin Basis for PA chest PA chest dose

R front shoulder EXSD 1.29E–03

R back shoulder ENSD 3.78E–02

L front shoulder EXSD 1.29E–03

L back shoulder ENSD 3.78E–02

R upper arm to elbow 10% ENSD 3.78E–03

L upper arm to elbow 10% ENSD 3.78E–03

L hand 10% ENSD 3.78E–03

R hand 10% ENSD 3.78E–03

L elbow, forearm, wrist 10% ENSD 3.78E–03

R elbow, forearm, wrist 10% ENSD 3.78E–03

R side of head (including temple and ear) 10% ENSD 3.78E–03

L side of head (including temple and ear) 10% ENSD 3.78E–03

Front left thigh RSD (0.52m) 1.49E–05

Back left thigh RSD (0.52m) 1.49E–05

Front right thigh RSD (0.52m) 1.49E–05

Back right thigh RSD (0.52m) 1.49E–05

L knee and below RSD (0.86m) 5.43E–06

R knee and below RSD (0.86m) 5.43E–06

L side of face Eye/brain 2.08E–03

R side of face Eye/brain 2.08E–03

L side of neck 10% ENSD 3.78E–03

R side of neck 10% ENSD 3.78E–03

Back of head 10% ENSD 3.78E–03

Front of neck Thyroid 2.08E–03

Back of neck 10% ENSD 3.78E–03

Front torso: base of neck to end of sternum EXSD 1.29E–03

Front torso: end of sternum to lowest rib EXSD 1.29E–03

Front torso: lowest rib to iliac crest 10% EXSD 1.29E–04

Front torso: iliac crest to pubis 10% EXSD 1.29E–04

Back torso: base of neck to mid-back ENSD 3.78E–02

Back torso: mid-back to lowest rib ENSD 3.78E–02

Back torso: lowest rib to iliac crest 10% ENSD 3.78E–03

Back torso: buttocks (Iliac crest and below) 10% ENSD 3.78E–03

Right torso: base of neck to end of sternum ENSD 3.78E–02

Right torso: end of sternum to lowest rib ENSD 3.78E–02

Right torso: lowest rib to iliac crest 10% ENSD 3.78E–03

Right torso: iliac crest to pubis (R hip) 10% ENSD 3.78E–03

Left torso: base of neck to end of sternum ENSD 3.78E–02

Left torso: end of sternum to lowest rib ENSD 3.78E–02

Left torso: lowest rib to iliac crest 10% ENSD 3.78E–03

Left torso: iliac crest to pubis (L hip) 10% ENSD 3.78E–03

a. ENSD = entrance skin dose; EXSD = exit skin dose; RSD = remote skin dose.