ORAU Team

NIOSH Dose Reconstruction Project

Technical Basis Document for the Rocky Flats Plant – 

Occupational Medical Dose

Document Number:

ORAUT-TKBS-0011-3 

Effective Date: 02/09/2004 

Revision No.: 00

Controlled Copy No.: ________

Page 1 of 27

Subject Experts: Joe Furman, Theresa Lopez

Document Owner

Approval: Signature on File___________ Date: 02/10/2004 

Robert Meyer, TBD Team Leader

Approval: Signature on File __________ Date: 02/10/2004 

Judson L. Kenoyer, Task 3 Manager

Concurrence: Signature on File ________ Date: 02/10/2004 

Richard E. Toohey, Project Director

Approval: Signature on File __________ Date: 02/11/2004 

James W. Neton, OCAS Health Science Administrator

Supersedes:

None

TABLE OF CONTENTS

Section

Record of Issue/Revisions ...................................................................................................................

Page

3

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

3.0 Occupational Medical Dose ........................................................................................................8

3.1 Introduction ........................................................................................................................8

3.2 Examination Frequency......................................................................................................9

3.3 Equipment and Techniques................................................................................................9

3.4 Organ Dose Estimates ..................................................................................................... 10

3.4.1 Parameters and Estimation Method...................................................................... 10

3.4.2 Organ Dose Estimates for RFP Workers............................................................... 12

3.5 Uncertainties ....................................................................................................................12

References ........................................................................................................................................22

Glossary ............................................................................................................................................23

LIST OF TABLES

Table

3.2-1 Known X-ray examination frequencies .............................................................................

Page

14

3.3-1 Description of X-ray equipment used at RFP and proxy information................................. 14

3.3-2 Equipment settings and ratings ........................................................................................ 14
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3.4.1-1 ICRP dose conversion factors; absorbed dose (1 mGy) for organs at 

various AL HVL ................................................................................................................15

3.4.1-2 Analogs for IREP organs not specified in ICRP (1982)..................................................... 15

3.4.2-1 Organ dose estimates for PA chest (mGy) ....................................................................... 16

3.4.2-2 Organ dose estimates for AP and LAT Lumbar Spine ...................................................... 18

3.4.2-3 Organ Dose Estimates for Photofluorography, 1953 through 1968................................... 19

3.5-1 Doses to IREP Organs, adjusted for uncertainty of 30% PA Chest Xray (rem) ..........................................................................................................................20

3.5-2 Doses to IRP Organs from Chest Photofluorography, 1953 to 1968 

(rem). Adjusted for Uncertainty of 30%............................................................................ 21

LIST OF FIGURES

Figure

3.4.1-1 Kerma in air at 1 meter from X-ray source as a function of total filtration for various 

values of tube potential

Page

11
Effective Date: 02/09/2004 Revision No. 00 Document No. ORAUT-TKBS-0011-3 Page 3 of 27

RECORD OF ISSUE/REVISIONS

ISSUE 

AUTHORIZATION 

DATE

EFFECTIVE 

DATE

REV. 

NO. DESCRIPTION

Draft 10/31/2003

00-A 

New Technical Basis Document for the Rocky 

Flats Plant – Occupational Medical Dose. 

Initiated by Robert Meyer.

Draft 11/26/2003

00-B 

Revised in accordance with comments received 

10/14/03 and 11/14/03 (all comments received to 

date). Initiated by Robert Meyer.

Draft 12/26/2003 00-C Photofluorography assumptions modified per 

email messages this week. Initiated by Robert 

Meyer.

Draft 01/05/2004 00-D Modified per ORAU (Elyse Thomas) comments 

received 12/30/03. Initiated by Robert Meyer.

Draft 02/02/2004 00-E Incorporates NIOSH review comments. Initiated 

by Robert Meyer.

Draft 02/06/2004 00-F Modified per discussions with Mr. Tim Taulbee. 

Initiated by Robert Meyer.

02/09/2004 02/09/2004 00 First approved issue. Initiated by Robert Meyer.
Effective Date: 02/09/2004 Revision No. 00 Document No. ORAUT-TKBS-0011-3 Page 4 of 27

ACRONYMS AND ABBREVIATIONS

α alpha particle

AEC (U.S.) Atomic Energy Commission

AECL Administrative Exposure Control Level

AED Aerodynamic Equivalent Diameter

AEDE Annual Effective Dose Equivalent 

AP anterior-posterior

AWE Atomic Weapons Employer

β beta particle 

CATI Computer Assisted Telephone Interview 

CDPHE/CDH Colorado Department of Public Health and Environment (Previously Colorado 

Department of Health)

CEDE Committed Effective Dose Equivalent (replaced the AEDE in 1992)

CFR Code of Federal Regulations

c/m counts per minute 

DAC Derived Air Concentration

DE Dose Equivalent

DL Detection Limit

DOE U.S. Department of Energy

DOELAP DOE Laboratory Accreditation Program 

DOL Department of Labor

DU Depleted Uranium

EEOICPA Energy Employees Occupational Illness Compensation Program Act

EPA Environmental Protection Agency (U.S.)

ERDA Energy Research & Development Administration

ETF Effluent Treatment Facility
Effective Date: 02/09/2004 Revision No. 00 Document No. ORAUT-TKBS-0011-3 Page 5 of 27

γ gamma ray

Gy gray

HEU Highly Enriched Uranium

HHS Department of Health and Human Services

Hp(10) Personal Dose Equivalent

HPRED Health Protection Radiation Exposure Database 

HPAREH Health Protection Annual Radiation Exposure History Database 

HVL Half-value layers

IARC International Agency for Research on Cancer

ICRP International Commission on Radiological Protection

IMBA Integrated Modules for Bioassay Analysis 

IREP Interactive RadioEpidemiological Program

kerma kinetic energy released per unit mass

keV kilo electron Volt

kV kilovolt

kVp kilovolt-peak

LANL Los Alamos National Laboratory

LAT lateral

LLD Lower Limit of Detection

mA milliamp-second

MDA Minimum Detectable Activity

MDL Minimum Detection Limit

MED Manhattan Engineering District

MEPAS Multimedia Environmental Pollutant Assessment System

mGy milligray

mmAl millimeters of aluminum
Effective Date: 02/09/2004 Revision No. 00 Document No. ORAUT-TKBS-0011-3 Page 6 of 27

NCRP National Council on Radiation Protection and Measurements

NIOSH National Institute for Occupational Safety and Health

NOCTS NIOSH Occupational Claims Tracking System

NTA Nuclear Track Emulsion

OCAS Office of Compensation Analysis and Support

ORAU Oak Ridge Associated Universities

ORNL Oak Ridge National Laboratory

PA posterior-anterior (medical x-ray)

PAS Personal Air Sampler

PIC Pocket Ionization Chamber (i.e., “Pencil” dosimeter)

Pu Plutonium

R Roentgen

RAS Regional Air Sampler

RBE Relative Biological Effectiveness

RC & HP Radiological Control and Health Physics Department 

rem Roentgen equivalent man

rep Roentgen equivalent physical

RFP Rocky Flats Plant

RRF Resin Regeneration Facility

RTF Replacement Tritium Facility

RU Recycled Uranium

s second

SEC Special Exposure Cohort

SID source to image distance

SRS Savannah River Site
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SSD source to skin distance

SWDF Solid Waste Disposal Facility

TBD Technical Basis Document

TEPC Tissue Equivalent Proportional Counter

TLD Thermoluminescent Dosimeter

TLND Thermoluminescent Neutron Dosimeter

TPO Technical Procedures Office

TRU Transuranic

U.S.C. United States Code

WCF Waste Certification Facility
Effective Date: 02/09/2004 Revision No. 00 Document No. ORAUT-TKBS-0011-3 Page 8 of 27

3.0

As part of the requirements for employment at the Rocky Flats Nuclear Weapons Plant (RFP), 

entrance, exit, and periodic physical examinations were performed on all employees. These physical 

examinations could include radiographic examinations of the lungs and, for some employees, the 

lumbar spine. Because these examinations were required for employment, the Office of 

Compensation Analysis and Support (OCAS) External Dose Reconstruction Implementation 

Guidelines (OCAS 2002) and 42 CFR Part 82, the implementing regulation for the Energy Employees 

Occupational Illness Compensation Program Act of 2000 (Public Law 106-398) consider the X-ray 

doses to be part of the occupational radiation exposure. Only medical exposures that were required 

as a condition of employment are included; diagnostic and therapeutic procedures not required for 

employment are excluded.

OCCUPATIONAL MEDICAL DOSE

The following sections describe the methodology used to estimate absorbed dose from X-ray 

exposure for RFP workers. In the absence of available data, assumptions are generally conservative 

(claimant-favorable). Section 3.1 provides introductory text. Section 3.2 describes X-ray examination 

frequency at Rocky Flats. Section 3.3 provides information on equipment and techniques used at 

Rocky Flats, including assumptions necessitated by lack of protocol, measurement, or records data. 

Section 3.4 provides organ dose estimates by calendar year and type of X-ray. Section 3.5 

documents uncertainties. 

3.1 Introduction

As described in Protection of the Patient in Diagnostic Radiology (ICRP 1982), the amount of energy 

absorbed in the body and its distribution in specific organs can be determined by measurement or 

calculation. Absorbed dose in tissue, measured in units of gray (Gy), is equal to the energy absorbed 

per unit mass at a point in the human body. The quantity of radiation in terms of exposure from 

ionization of a specific mass of air by X-rays was in previous years measured in roentgens (R). The 

current international system of units expresses this quantity in air kerma (kerma is an acronym for 

kinetic energy released per unit mass). An exposure of 1 R corresponds to an air kerma of 8.7 mGy.

The radiation dose received in a given examination varies widely throughout the body. Doses are 

highly dependent on the technical factors employed, characteristics of the equipment, collimation of 

the beam, and number of films taken. The general equation for total annual occupational medical 

dose provided by OCAS guidelines (OCAS 2002) is:

Dom = ΣnDi (3.1–1)

where 

Dom = occupational medical dose

n = number of exams in a calendar year

Di = dose from the X-ray procedure

The OCAS guidelines direct that medical records should contain the dates, types, and number of 

X-ray examinations, and that if no information is known about the energy spectra, values should 

conservatively be assumed to be in the 30 to 250 kV photon range (a claimant-favorable assumption). 

The guidance states that the uncertainty distribution about each X-ray procedure is assumed to follow 

a normal distribution, with Dom being the mean dose. 
Effective Date: 02/09/2004 Revision No. 00 Document No. ORAUT-TKBS-0011-3 Page 9 of 27

3.2 Examination Frequency

The frequency of X-ray examinations varied significantly for RFP workers (Table 3.2-1). A protocol for 

frequency of a single PA (posterior-anterior) view chest X-ray as a function of job category was not 

established until approximately 1986. After that date, the frequency of routine chest X-rays varied 

widely: none for office personnel, every 5 years for respirator wearers, and annually for beryllium and 

asbestos workers over age 45 and with a 10-year history of asbestos exposure. Before approximately 

1986, many production workers would receive single-view chest X-rays on a nearly annual basis. (In 

a sample of medical records of production workers, no one was found to have consistently received 

annual chest X-rays, due to occasional missed examinations and periods when examinations were 

apparently not provided on an annual basis.) Inspection of medical records has not revealed any 

more specific designation of workers who would receive nearly annual chest X-rays. Based on the 

records reviewed during preparation of this document, no worker received such exams more often 

than annually.

Between 1952 and 1974, all workers received spinal X-rays during their initial employment medical 

examination. This X-ray series consisted of a 14- by 17-in. anterior-posterior (AP) view and a 10- by 

12-in. lateral (LAT) view of the lumbosacral spine.

Without a review of the specific claimant’s X-ray file (stored at the Denver Federal Center), an exact 

count of the X-rays is impossible. The medical files (also stored at the Denver Federal Center) did not 

always document each X-ray taken, at least not in the years before the mid-1970’s. A claimantfavorable approach to the estimation of the X-rays taken would therefore assume lumbosacral spine 

X-rays were taken if the claimant started work between 1952 and 1974. If an annual single-view 

chest X-ray is also assumed, this potential overestimation of X-ray use would compensate for the few 

“retakes” necessary because of poor quality of the initial x-ray.

3.3 Equipment and Techniques

Although RFP radiological practices are assumed to have followed standards of medical practice to 

minimize dose to the patient, the type of equipment, technique factors, and machine calibrations are 

not fully known for years before 2001. Members of the Rocky Flats TBD team interviewed Medical 

and Records group staff and Colorado Department of Public Health and Environment staff, and 

determined that X-ray machine records for equipment in use before 2001 are not readily available. 

However, some information has been located regarding equipment type and ratings; this data has 

been used provided in conjunction with default data where needed to provide claimant-favorable 

estimates of potential exposure. Individual medical records should contain notations about dates and 

purposes of X-ray examinations, but reviews of medical records showed that this was not always the 

case before the mid-1970s. 

X-ray organ dose estimates for occupational X-rays administered at RFP are provided here for known 

equipment (Type I – June 11, 2001, to present) and default estimates are provided for earlier time 

periods (ORAU 2003a). The use of proxy data is based on the belief that RFP, like other DOE sites, 

used the standard radiological procedures of the time. All assumptions made were conservative 

(claimant-favorable). The default dose estimates are from the Complex-Wide X-ray Technical 

Information Bulletin (TIB) (ORAU 2003a) for chest X-rays, and from information presented in Lincoln 

and Gupton (1958) for lumbar spine X-rays. 

Photofluorography may have been performed at RFP. While no particular records or protocol have 

been found, a note indicating that a fluoroscope was removed from the plant in 1968 indicates that 

photofluorography could have been performed. As no further site-specific information has been found 
Effective Date: 02/09/2004 Revision No. 00 Document No. ORAUT-TKBS-0011-3 Page 10 of 27

to date, default estimates of exposure from the Complex-Wide TIB (ORAU 2003a) have been used in 

this report.

Efforts will continue to locate all related information for RFP. However, until more accurate records 

are located, these assumptions provide the most claimant-favorable estimates.

Tables 3.3-1 and 3.3-2 summarize known information regarding equipment and techniques.

3.4 Organ Dose Estimates

Organ dose estimates are provided in this section. Section 3.4.1 describes the methodology used to 

estimate these doses; Section 3.4.2 discusses the results. 

3.4.1

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

Parameters and Estimation Method

1. Source to image distance (SID) in centimeters (cm)

2. Total Filtration (millimeters of aluminum, mm Al) 

3. Estimate of patient thickness (AP and LAT)

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

If measured air kerma data are available, these should be used. If not, air kerma rates can be 

estimated from Figure 3.4.1-1.

Figure 3.4.1-1 is for single-phase machines; results should be multiplied by 1.8 for three-phase 

machines. All X-ray machines at RFP were assumed to be 3-phase, as a conservative measure. 

Once the kerma rate is estimated, the air kerma at 100 cm is calculated by multiplying the estimated 

air kerma rate by the number of mA used for each radiograph.

Next, the source to skin distance (SSD) is calculated by subtracting the AP or LAT thickness of the 

patient and distance between the patient and the film (default distance of 5 cm) from the SID. Air 

kerma at the SSD is then estimated using the following equation:

air kerma at SSD (mGy) = (100/SSD)2 x air kerma at 1 meter (mGy) (3.4.1–1)

Tables A-2 through A-9 of ICRP 34 (1982) are then used to estimate organ dose directly. Dose to the 

skin was estimated by multiplying the air kerma at SSD by the appropriate factor from Table B-8 of the 

National Council of Radiation Protection and Measurements Report 102 (NCRP 1989). The tables list 

organ doses in mGy normalized to an air kerma of 1 Gy in air at the skin, as a function of half-value 

layers (HVL) in millimeters of aluminum. In addition, ICRP (1982) Appendix A provides tables for 

estimating the HVL if it is not known. Table 3.4.1-1 lists all such values used in this report.

The ICRP tables used to estimate absorbed dose do not include all organs that have been identified 

in the Interactive RadioEpidemiological Program (IREP) computer program. For those organs 

included in the IREP but not specifically identified in the ICRP tables, the dose conversion coefficient 

that is anatomically closest to the IREP-specified organs may be used to estimate dose. For 

example, the factor for lung can be applied to all other organs in the thoracic cavity, such as the 

esophagus and bone surface. For abdominal organs (bladder, colon), the dose coefficient for 
Effective Date: 02/09/2004 Revision No. 00 Document No. ORAUT-TKBS-0011-3 Page 11 of 27

ovaries should be used. This approach should 

be either claimant-favorable or neutral. Table 

3.4.1-2 provides analogs for IREP organs.

To determine doses from lumbar spine x-rays, 

data from Lincoln and Gupton (1958) was used 

to create probability distributions for each organ 

listed in ICRP 34 (1982). The paper listed 

doses to skin, testes, and ovaries from several 

different x-ray examination procedures at eight 

Oak Ridge National Laboratory (ORNL) 

facilities. Doses were measured using a 

manikin, and both filtration and collimation 

varied by facility, reflecting typical procedures 

employed at each facility at the time.

To create the probability distributions, the 

entrance skin exposures (ESEs) listed in the 

Lincoln and Gupton paper (1958) for AP and 

LAT lumbar spine x-rays was entered into 

Crystal Ball software (Decisioneering Inc. 

2000) to predict a distribution of exposure for 

each view. Then, corrected for units, the ESEs 

were multiplied by a distribution of dose 

conversion factors for AP and LAT lumbar spine 

x-rays for each organ listed in ICRP 34 (1982). 

Dose conversion factors corresponding to total 

filtrations of 1.5 mmAl to 3.0 mmAl were used in 

the calculations. This assumption is necessary 

because filtration values presented in the 

Lincoln and Gupton paper (1958) ranged from 0 

mmAl to 3.0 mmAl; it is unknown whether these 

values represented added or total filtration. 

Further, the ICRP 34 tables present dose 

conversion factors for total filtration only, with a 

minimum of 1.5 mmAl and maximum of 4.0 

mmAl. It was assumed that 3.0 mmAl was the 

maximum filtration for this time period and view. 

The dose conversion factors were assumed to have uniform distribution (equal probability of 

occurrence).

The resulting forecasts of dose for each organ were used to estimate average dose for AP and LAT 

lumbar spine x-rays, with one exception. The dose to the testes predicted by the model did not 

correspond to the measured doses; this is due to restrictive collimation assumed in the dose 

conversion factors. Lack of collimation resulted in higher measured dose in the Lincoln and Gupton 

paper (1958). The measured dose to the testes, therefore, was used in these dose estimates (the 

geometric mean after removal of one extreme upper-bound value in both the AP and LAT estimates) 

(Lopez 2004). For each organ, the geometric mean of the forecasted estimates (or measured dose, 

for the testes) was used as the dose. Results are listed in Table 3-4.2-2 and supporting material is 

provided as Attachment A to this section.

Figure 3.4.1-1. Kerma in air at 1 meter from X-ray 

source as a function of total filtration for various 

values of tube potential (from ICRP 1982). 
Effective Date: 02/09/2004 Revision No. 00 Document No. ORAUT-TKBS-0011-3 Page 12 of 27

Photofluorography could have been used at RFP, but no information regarding protocol has been 

located. Lacking any further information on photofluorograpy at RFP (notes indicate only that a 

fluoroscope was removed in 1968) default dose estimates from the Complex-Wide TIB have been 

used. It is assumed, until further information is located, that the frequency of photofluorography was 

once per year from 1953 to 1968, and that it was used for the chest only. 

3.4.2

Table 3.4.2-1 lists default and calculated organ dose estimates from PA chest X-rays for each period. 

Table 3.4.2-2 lists the calculated organ dose estimates for AP and LAT lumbar spine X-rays (derived 

from information in Lincoln and Gupton 1958). Table 3.4.2-3 presents default photofluorography 

exposure from chest examinations, as reported in the Complex-Wide TIB (ORAU 2003a).

Organ Dose Estimates for RFP Workers

Note that some estimates for exposure from PA chest X-rays from 1953 to 2001 are based on 

information taken from the Complex-Wide TIB (ORAU 2003a). Specifically, default estimates for time 

periods prior to 2001 have been used. For lumbar spine dose estimates, measured and estimated 

doses from information in Lincoln and Gupton (1958) have been used, as described above, as sitespecific information is currently unavailable.

In addition, estimated doses associated with photofluorography have been taken from the ComplexWide TIB (ORAU 2003a), as no information is available at this time for RFP. As noted above, 

photofluorography may have been used at RFP prior to 1968.

3.5 Uncertainties

As stated in the Complex-Wide TIB and Savannah River Site TBD (ORAU 2003a,b), error is defined 

as deviation from the correct, true, or conventionally accepted value of a quantity and uncertainty is 

defined in terms of the potential range of a stated, measured, or assumed or otherwise determined 

value of a quantity. Error and uncertainty provide an indication of confidence in the dose estimates. 

Uncertainty, expressed in terms of a confidence level, is a more appropriate term than error, which 

implies that the actual value is known. Uncertainty, stated as a probability of falling within a stated 

range, includes precision and reproducibility of the measurement as well as accuracy (that is, how 

close the estimate comes to the actual value).

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

contribute the most uncertainty to the dose estimate: measurement error, variation in applied 

kilovoltage, variation in beam current, variation in exposure time, and SSD. Film speed, use of 

screens, or the use of grids would not affect the beam output intensity. The lack of historical records 

for these measurements for most years at Rocky Flats introduces a large uncertainty into the dose 

estimates that cannot be readily quantified, although there is no apparent reason to believe that 

practices at Rocky Flats were different from those at other facilities or from 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. The following estimates of uncertainty associated with X-ray exposure are 

from ORAU 2003a, which was relied upon for default information. Further, these same factors affect 

dose estimates of photofluorographic X-rays; proxy default information for photofluorography was 

taken from Complex-Wide (ORAU 2003a) in the absence of useful records at RFP.

The Complex-Wide TIB (ORAU 2003a) reports that X-ray doses are largely derived from actual 

measurements of X-ray machine output with R-meters or similar ionization chamber devices. 

Reportedly, these typically had an uncertainty of +2% for photon energies below 400 keV, if properly 
Effective Date: 02/09/2004 Revision No. 00 Document No. ORAUT-TKBS-0011-3 Page 13 of 27

calibrated and used. Although machinery that is more current may have a smaller uncertainty, +2% 

should be used to be conservative.

Variation in applied voltage generally falls within +5% of the machine setting. Beam intensity is 

approximately proportional to the 1.7 power of the kilovoltage, resulting in an uncertainty of 

approximately 9% in relation to beam intensity for voltages in the 110- to 120-kVp range. 

Variations in tube current are normal and generally small. As tube current drops, beam intensity also 

falls in direct proportion to the tube current. Large decreases in beam output would be readily 

detected and would indicate the need for machine maintenance or, as a temporary measure, an 

increase in the current or voltage to provide the necessary intensity for proper radiography. However, 

there is no evidence that such a procedure was ever needed or applied at RFP. The Complex-Wide 

TIB estimates the variation in tube current to be approximately +2% (ORAU 2003a), while the 

Savannah River Site TBD listed a variation of +5% for this parameter (ORAU 2003b). To be 

conservative, +5% is recommended for RFP.

Exposure time may also significantly affect the dose received from radiography (exposure times are a 

fraction of second). Even a small variation in exposure time, due to timer error, can significantly 

change beam output. Because early X-ray machine timers are known to have been inaccurate, 

uncertainty in beam output due to timers is assumed to be +25% in both the Complex-Wide TIB and 

Savannah River TBD documents (ORAU 2003a,b). Therefore, it is recommended that +25% be 

applied for RFP estimates, particularly since site-specific exposure time was available only for the 

present machine.

Last, SSD may contribute to variability, because the entrance skin exposure is determined by this 

distance. Variations result from accuracy of positioning as well as patient size (thickness). As 

expressed in the Complex-Wide TIB and Savannah River TBD documents, this is generally thought to 

vary by no more than a few centimeters, with an upper limit of 7.5 cm (+10%) (ORAU 2003a,b). 

A potentially large source of uncertainty for RFP is the number of X-rays taken. As noted previously, 

medical files reviewed for this TBD showed that the files did not always document X-rays taken, at 

least before the mid-1970s. Further, the frequency of photofluorography is completely unknown. It is 

recommended that, as a conservative approach, an annual chest X-ray should be assumed for all 

claimants. It should also be assumed that AP and LAT lumbar spine X-rays were taken at the start of 

employment for all individuals employed from 1952 to 1974. Unless otherwise indicated in an 

employee’s medical record, an annual photofluorography x-ray of the chest should be assumed from 

1953 to 1968.

Consistent with the Complex-Wide TIB and Savannah River Site TBD, the statistical root mean 

square was calculated to estimate total uncertainty (ORAU 2003a,b). The root mean square is the 

square root of the sum of the squares of the individual uncertainty values, and equals 28.9%. An 

estimate of 30% uncertainty is larger than the default OCAS guidance standard deviation 

recommendation of 20% (OCAS 2002). Therefore, all final estimates were multiplied by 1.3 to 

account for uncertainty, conservatively assuming that all variables acted to increase dose (Tables 3.5-

1. 3.5-2, and 3.5-3). 
Effective Date: 02/09/2004 Revision No. 00 Document No. ORAUT-TKBS-0011-3 Page 14 of 27

Table 3.2-1. Known X-ray examination frequencies. 

Period Frequency View Comment

1986-present Annually Chest (PA) Beryllium and asbestos workers over age 45 years 

with 10 year work history exposure to asbestos

Every 5th year Chest (PA) Respirator wearers

None Chest (PA) Office personnel

1952-1985 Annual Chest (PA) Production workers

1952-1974 Once Lumbar (AP and LAT) All workers

Table 3.3-1. Description of X-ray equipment used at RFP and proxy information. 

Classification Period Equipment Source

Type I June 11, 2001-

present

Hologic/BXT202W Furman 2003b; Dean, 2003

Type II May 29, 1987 – 

March 6, 2001

Eureka XMA tube; Generator 

unknown

Furman 2003c; Dean, 2003

Type III September 1, 1976-

May 28, 1987

Generator unknown; Victoreen 

R Meter; BRH test stand; X-ray 

Timer; Aluminum Filter set; light 

meter

Dean, 2003

Type IV July 1953-August 

30,1976

Keleket Dean, 2003

Table 3.3-2. Equipment settings and ratings. 

Machine Period View Current (mA) Voltage (kVp) Exposure time (s)

Type 1a 6/11/2001-present Chest PA 300 110 1/130

Type II b 5/29/1987-3/6/2001 Chest PA 360 130 Unknown

Type III b 9/01/1976-5/28/1987 Chest PA Unknown 80 Unknown

Type IV b 7/1953- 8/30/1976 Chest PA 200 140 Unknown

Lumbar AP c 200 140 Unknown

Lumbar LAT c 200 140 Unknown

a. Typical setting varies from 0.8 mA for an average-sized person to 2.3 mA for a very large person; 2.3 mA was used to 

be conservative.

b. Maximum machine ratings; data not used to calculate doses, but is presented for informational purposes.

c. Performed only from 1952 through 1974; settings are maximum machine ratings.
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Table 3.4.1-1. ICRP dose conversion factors; absorbed dose (1 mGy) for organs at various Al HVL (1 

Gy entrance air kerma in air without backscatter). Image size 35.6 cm x 43.2 cm.

Organ

Chest PA

(pre-1970) 

(a,b)

at 2.5 mm Al 

HVL

SID = 183 

cm

Entrance 

Kerma = 

0.20 cGY

Chest PA (a)

(1970 to 1985)

at 2.5 mm Al 

HVL

SID = 183 cm

Entrance 

Kerma = 0.10 

cGy

Chest PA (a)

(1985 to 

present) 

at 4 mm Al HVL

SID = 183 cm

Entrance Kerma 

= 0.05 cGy 

(prior to 2001)

Lumbar spine (d)

range for 1.5 to 

3.0 mm Al HVL

AP 

Lumbar spine (d)

Range for 

1.5 to 3.0 mm Al 

HVL

LAT

Thyroid 174 (c) 32 78 0.06-0.6 0.01-0.01

Eye/Brain 32 32 78 0.06-0.6 0.01-0.01

Ovaries N/A 1 5.2 105-274 17-67

Liver/Gall 

Bladder/Spleen

451 451 674 45-95 0.2-1.2

Urinary 

Bladder

N/A 1 5.2 105-274 17-67

Colon/Rectum N/A 1 5.2 105-274 17-67

Testes N/A 0.01 0.01 ---- ----

Lungs (male) 419 419 628 45-95 6-17

Lungs (female) 451 451 674 45-95 6-17

Thymus 451 451 674 45-95 6-17

Esophagus 451 451 674 45-95 6-17

Stomach 451 451 674 45-95 6-17

Bone Surfaces 451 451 674 45-95 6-17

Remainder 451 451 674 45-95 6-17

Breast 49 49 116 NC NC

Uterus 

(embryo)

N/A 1.3 5.2 147-355 11-45

Bone marrow 

(male)

92 92 178 15-53 9.4-31

Bone marrow 

(female)

86 86 172 15-53 9.4-31

Skin N/A N/A N/A ---- ----

N/A = as reported in ORAU 2003a

NC = Not computed, but small in comparison to other organs

(a) Dose Conversion Factors from Tables A.2 through A.9, ICRP 1982 (ORAU 2003a); --- indicates not used; 

measured dose used instead of estimate

(b) Assumes minimal collimation

(c) Dose Conversion Factor for AP c-spine, corrected for depth by 0.2

(d) From ORAU 2003c.

Table 3.4.1-2. Analogs for IREP organs not specified in ICRP (1982). 

Anatomical location ICRP #34 reference 

organ IREP organ analogues

Thoracic cavity Lung Thymus

Esophagus

Stomach

Bone surface

Liver/gall 

bladder/spleen

Remainder organs 

Abdominal cavity Ovaries Uterus

Urinary bladder

Colon/rectum

Head and neck Thyroid Eye/brain
Effective Date: 02/09/2004 Revision No. 00 Document No. ORAUT-TKBS-0011-3 Page 16 of 27

Table 3.4.2-1. Organ dose estimates for PA chest (mGy). 

Time period: June 11, 2001 to present

Organ

Estimated dose

HVL = 4.0 mmAL

Air kerma at skin = 0.134 mGy

mGy rem

Thyroid 1.05E-02 1.05E-03

Eye/Brain 1.05E-02 1.05E-03

Ovaries 6.99E-04 6.99E-05

Liver/gall 

bladder/spleen

6.99E-04 6.99E-05

Urinary Bladder 6.99E-04 6.99E-05

Colon/Rectum 6.99E-04 6.99E-05

Testes 1.34E-06 1.34E-07

Lungs (male) 8.44E-02 8.44E-03 

Lungs (female) 9.06E-02 9.06E-03

Thymus 9.06E-02 9.06E-03

Esophagus 9.06E-02 9.06E-03

Stomach 9.06E-02 9.06E-03

Bone Surfaces 9.06E-02 9.06E-03

Remainder 9.06E-02 9.06E-03

Female breast 1.56E-02 1.56E-03

Uterus 6.99E-04 6.99E-05

Bone marrow 

(male)

2.39E-02 2.39E-03 

Bone marrow 

(female)

2.31E-02 2.31E-03

Skin 1.91E-01 1.91E-02

Time Period: 1985 to June 4, 2001

Organ

Estimated dose (a)

HVL = 4.0 mmAl; 

Entrance Kerma = 0.05 cGy

mGy rem

Thyroid 3.9E-02 3.9E-03

Eye/Brain 3.9E-02 3.9E-03

Ovaries 2.6E-03 2.6E-04

Liver/gall 

bladder/spleen

3.37E-01 3.37E-02

Urinary Bladder 2.60E-03 2.60E-04 

Colon/Rectum 2.60E-03 2.60E-04

Testes 5.00E-06 5.00E-07

Lungs (male) 3.14E-01 3.14E-02 

Lungs (female) 3.37E-01 3.37E-02

Thymus 3.37E-01 3.37E-02

Esophagus 3.37E-01 3.37E-02

Stomach 3.37E-01 3.37E-02

Bone Surfaces 3.37E-01 3.37E-02

Remainder 3.37E-01 3.37E-02

Female breast 5.80E-02 5.80E-03

Uterus 2.6E-03 2.6E-04

Bone marrow 

(male)

8.90E-02 8.90E-03

Bone marrow 

(female)

8.6E-02 8.6E-03

Skin 7.00E-01 7.00E-02 
Effective Date: 02/09/2004 Revision No. 00 Document No. ORAUT-TKBS-0011-3 Page 17 of 27

Table 3.4.2-1. Organ dose estimates for PA 

chest (continued) 

Time Period: post 1970 to 1985 

Organ

Estimated dose (a)

HVL = 2.5 mmAl; 

Entrance Kerma = 0.10 cGy

mGy rem

Thyroid 3.2E-02 3.2E-03

Eye/Brain 3.2E-02 3.2E-03

Ovaries 1.0E-03 1.0E-04

Liver/gall 

bladder/spleen

4.51E-01 4.51E-02

Urinary Bladder 1.00E-03 1.00E-04 

Colon/Rectum 1.00E-03 1.00E-04

Testes 1.00E-05 1.00E-06

Lungs (male) 4.19E-01 4.19E-02 

Lungs (female) 4.51E-01 4.51E-02

Thymus 4.51E-01 4.51E-02

Esophagus 4.51E-01 4.51E-02

Stomach 4.51E-01 4.51E-02

Bone Surfaces 4.51E-01 4.51E-02

Remainder 4.51E-01 4.51E-02

Female breast 4.90E-02 4.90E-03

Uterus 1.30E-03 1.30E-04

Bone marrow 

(male)

9.20E-02 9.20E-03

Bone marrow 

(female)

8.6E-02 8.6E-03

Skin 1.35E+00 1.35E-01 

(a) as presented in ORAU 2003a

(b) Modified from Webster (1957) as presented 

in ORAU 2003a

Time Period: pre-1970

Organ

Estimated dose (a)

HVL = 2.5 mmAl; 

Entrance Kerma = 0.20 cGy

mGy rem

Thyroid 3.48E-01 3.48E-02

Eye/Brain 6.4E-02 6.4E-03

Ovaries 2.5E-01 (b) 2.5E-02 (b)

Liver/gall 

bladder/spleen

9.02E-01 9.02E-02

Urinary Bladder 2.50E-01 (b) 2.50E-02 (b)

Colon/Rectum 2.50E-01 (b) 2.50E-02 (b)

Testes 5.00E-02 (b) 5.00E-03 (b)

Lungs (male) 8.38E-01 8.38E-02 

Lungs (female) 9.02E-01 9.02E-02

Thymus 9.02E-01 9.02E-02

Esophagus 9.02E-01 9.02E-02

Stomach 9.02E-01 9.02E-02

Bone Surfaces 9.02E-01 9.02E-02

Remainder 9.02E-01 9.02E-02

Female breast 9.80E-02 9.80E-03

Uterus 2.50E-01 (b) 2.50E-02 (b)

Bone marrow 

(male)

1.84E-01 1.84E-02

Bone marrow 

(female)

1.72-01 1.72-02

Skin 2.70E+00 2.70E-01 
Effective Date: 02/09/2004 Revision No. 00 Document No. ORAUT-TKBS-0011-3 Page 18 of 27

Table 3.4.2-2 Organ dose estimates for AP and LAT lumbar Spine.1 (1952-1974) 

Organ

AP lumbar spine1

HVL between 1.5 and 3.0 mm Al

ESE Averaged 1.79 rad

(rem)

LAT lumbar spine

HVL between 1.5 and 3.0 mm Al

ESE Averaged 5.79 rad

(rem)

Thyroid 5.00E-04 (2.96) 1.00E-04 (1.90)

Eye / Brain 5.00E-04 (2.96) 1.00E-04 (1.90)

Ovaries 3.27E-01 (2.56) 2.25E-01 (2.10)

Urinary Bladder 3.27E-01 (2.56) 2.25E-01 (2.10)

Colon / Rectum 3.27E-01 (2.56) 2.25E-01 (2.10)

Testes2 2.55E-02 (3.10) 3.97E-02 (1.51)

Lung 1.22E-01 (2.53) 6.36E-02 (2.00)

Liver / Gall Bladder / spleen 1.22E-01 (2.53) 6.36E-02 (2.00)

Thymus 1.22E-01 (2.53) 6.36E-02 (2.00)

Esophagus 1.22E-01 (2.53) 6.36E-02 (2.00)

Stomach 1.22E-01 (2.53) 6.36E-02 (2.00)

Bone Surfaces 1.22E-01 (2.53) 6.36E-02 (2.00)

Remainder 1.22E-01 (2.53) 6.36E-02 (2.00)

Female Breast3 1.35E-00 (2.40) 1.37E-00 (1.90)

Uterus 4.36E-01 (2.60) 1.51E-01 (2.10)

Bone Marrow 5.75E-02 (2.60) 1.10E-01 (2.10)

Skin2 1.79E-00 (2.44) 5.79E-00 (1.84)

1. All doses are geometric means in rem and the values in parenthesis are the corresponding geometric standard 

deviations.

2. Calculated from information presented in Lincoln and Gupton (1958). Doses to the skin and testes represent 

measured rather than calculated doses.

3. ICRP 34 (1982) does not provide dose conversion factors for the breast for the lumbar spin view. The true dose is 

between the skin dose and the lung dose. The breast dose was calculated using the DCFs for the Chest AP and 

LAT examinations. This is a claimant favorable proxy for the dose to the breast. 
Effective Date: 02/09/2004 Revision No. 00 Document No. ORAUT-TKBS-0011-3 Page 19 of 27

Table 3.4.2-3 Organ Dose Estimates for Photofluorography, 1953 through 1968 (as presented in the 

Complex-Wide TIB, ORAU 2003a). Entrance Kerma = 3 cGy; HVL = 2.5 mmAl; all estimates are for 

uncollimated beams . 

Organ View

Dose Conversion Factor 

(mGy per Gy air kerma) (a)

HVL 2.5 mm Al

Organ Dose (rem)

Uncollimated Uncollimated

Thyroid PA 174 (b) 5.20E-1

Eye/Brain PA 32 9.60E-2

Ovaries PA N/A 2.50E-2 (c )

Liver/Gall Bladder PA 451 1.35E+0

Urinary Bladder PA N/A 2.50E-2 (c )

Colon Rectum PA N/A 2.50E-2 (c )

Testes PA N/A 5.00E-3 (c )

Lungs (male) PA 419 1.26E+00

Lungs (female) PA 451 1.35E+00

Thymus PA 451 1.35E+00

Esophagus PA 451 1.35E+00

Stomach PA 451 1.35E+00

Bone Surfaces PA 451 1.35E+00

Remainder PA 451 1.35E+00

Breast PA 49 1.47E-1

Uterus PA N/A 2.50E-2 (c )

Bone Marrow 

(male)

PA 92 2.76E-1

Bone Marrow 

(female)

PA 86 2.58E-1

Skin (c) PA 4.05E+00

a. Dose conversion Factors from Tables A.2 through A.9, ICRP Publication 34 (1982). 

b. Dose Conversion Factor for AP C-spine, corrected for depth by 0.2 (ORAU 2003a). 

c. Modified from Webster, as reported in ORAU 2003a. 
Effective Date: 02/09/2004 Revision No. 00 Document No. ORAUT-TKBS-0011-3 Page 20 of 27

Table 3.5-1. Doses to IREP Organs, adjusted for uncertainty of 30% PA Chest X-ray (rem) 

Organ

June 11, 2001

to present

(Type I)

1985 to June 4,

2001 1970 to 1985 Pre-1970

Skin 2.48E-02 9.10E-02 1.76E-01 3.51E-01

Thyroid 1.36E-03 5.07E-03 4.16E-03 4.52E-02

Eye & Brain 1.36E-03 5.07E-03 4.16E-03 8.32E-03

Ovaries 9.08E-05 3.38E-04 1.30E-04 3.25E-02

Liver/Gall Bladder 9.08E-05 4.38E-02 5.86E-02 1.17E-01

Urinary/Bladder 9.08E-05 3.38E-04 1.30E-04 3.25E-02

Colon/Rectum 9.08E-05 3.38E-04 1.30E-04 3.25E-02

Testes 1.75E-07 6.50E-07 1.30E-06 6.50E-03

Lungs (male) 1.10E-02 4.08E-02 5.45E-02 1.09E-01

Lungs (female) 1.18E02 4.38E-02 5.86E-02 1.17E-01

Thymus 1.18E-02 4.38E-02 5.86E-02 1.17E-01

Esophagus 1.18E-02 4.38E-02 5.86E-02 1.17E-01

Stomach 1.18E-02 4.38E-02 5.86E-02 1.17E-01

Bone Surface 1.18E-02 4.38E-02 5.86E-02 1.17E-01

Remainder 4.38E-02 5.86E-02 1.17E-01

Breast 2.03E-03 7.54E-03 6.37E-03 1.27E-02

Uterus (embryo) 9.08E-05 3.38E-04 1.69E-04 3.25E-02

Bone Marrow 

(male) 3.11E-03 1.16E-02 1.20E-02 2.39E-02

Bone Marrow 

(female) 3.00E-03 1.12E-02 1.12E-02 2.24E-02

* the higher of female or male estimates were used for thymus, esophagus, stomach, and bone surface.
Effective Date: 02/09/2004 Revision No. 00 Document No. ORAUT-TKBS-0011-3 Page 21 of 27

Table 3.5-2. Doses to IRP Organs from Chest Photofluorography, 1953 to 

1968 (rem). Adjusted for Uncertainty of 30% 

Organ View

Organ Dose (rem) Adjusted Organ 

Dose

(rem)

Uncollimated Uncollimated

Thyroid PA 5.20E-1 6.76E-1

Eye/Brain PA 9.60E-2 1.25E-1

Ovaries PA 2.50E-2 3.25E-2

Liver/Gall 

Bladder

PA 1.35E+0 1.76E-2

Urinary 

Bladder

PA 2.50E-2 3.25E-2

Colon/ Rectum PA 2.50E-2 3.25E-2

Testes PA 5.00E-3 6.50E-3

Lungs (male) PA 1.26E+00 1.64E+00

Lungs 

(female)

PA 1.35E+00 1.76E+00

Thymus PA 1.35E+00 1.76E+00

Esophagus PA 1.35E+00 1.76E+00

Stomach PA 1.35E+00 1.76E+00

Bone Surfaces PA 1.35E+00 1.76E+00

Remainder PA 1.35E+00 1.76E+00

Breast PA 1.47E-1 1.91E-1

Uterus PA 2.50E-2 3.25E-2

Bone Marrow 

(male)

PA 2.76E-1 3.59E-1

Bone Marrow 

(female)

PA 2.58E-1 3.35E-1

Skin PA 4.05E+00 5.27E+00
Effective Date: 02/09/2004 Revision No. 00 Document No. ORAUT-TKBS-0011-3 Page 22 of 27

REFERENCES

Dean, A., 2003. “Regarding location of Rocky Flats X-ray documents,” memorandum to file, October 

21, MFG, Inc., Fort Collins, Colorado.

Decioneering Inc. 2000. Crystal Ball 2000 User Manual. Denver, Colorado.

Lopez, T., 2004, “Regarding discussion with T. Taulbee of OCAS concerning development of 

probability distributions for AP and LAT spine x-rays, January 23, MFG Inc., Fort Collins, 

Colorado.

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

Diagnostic Radiology, Publication 34, Pergamon Press, New York, New York.

Lincoln, T.A. Gupton, E.D. 1958. “Radiation Doses in Diagnostic X-ray Procedures.” Radiology. 

71:208-215.

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 No. 102, NCRP, Bethesda, MD

OCAS (Office of Compensation Analysis and Support ) 2002, External Dose Reconstruction 

Implementation Guidelines, Revision 1, OCAS-IG-001, National Institute for Occupational 

Safety and Health, Centers for Disease Control and Prevention, U.S. Department of Health 

and Human Services, Washington, D.C.

ORAU (Oak Ridge Associated Universities) 2003a, Technical Information Bulletin: Dose 

Reconstruction from Occupationally Related Diagnostic X-ray Procedures, ORAUT-OTIB0006, Oak Ridge, Tennessee. December 9, 2003.

ORAU (Oak Ridge Associated Universities) 2003b, Technical Basis Document for the Savannah River 

Site, ORAUT-TKBS-0003, Oak Ridge, Tennessee.

Public Law 106-398, Energy Employees Occupational Illness Compensation Program Act of 2000, 

(42 U.S.C. 7384 et seq.).

Webster, E.W., Merrill, O.E. 1957. “Measurements of Gonadal Dose in Radiographic Examinations.” 

New England Journal of Medicine. 257:811-819.
Effective Date: 02/09/2004 Revision No. 00 Document No. ORAUT-TKBS-0011-3 Page 23 of 27

GLOSSARY

alloy: a substance composed of two or more metals blended together.

annual dose equivalent: the dose equivalent received in a year. The annual dose equivalent is 

expressed in units of rem (sievert).

alpha particles: positively charged particles of discrete energies emitted by certain radioactive 

materials; alpha particles expend their energy in short distances and will not penetrate the outer 

layer of skin; they are a significant hazard only when taken into the body where their energy Is 

absorbed in living tissue.

Atomic Energy Commission: original agency established for nuclear weapons and power 

production; a predecessor to the U.S. Department of Energy.

beta dose: a designation (also, beta) on some external dose records referring to the dose from 

less-energetic beta, x-ray and/or gamma radiation. 

beta radiation: radiation consisting of charged particles of very small mass emitted 

spontaneously from the nuclei of certain radioactive elements. The beta particle is an electron 

moving at high velocity.

collective dose equivalent: the sum of the dose equivalents of all individuals in an exposed 

population. Collective dose is expressed in units of person-rem (person-sievert).

collective effective dose equivalent: the sum of the effective dose equivalents of all individuals 

in an exposed population. Collective effective dose is expressed in units of person-rem 

(person-sievert).

curie: a special unit of activity. One curie exactly equals 3.7 x 1010 nuclear transitions per 

second.

criticality: a self-sustaining nuclear fission reaction.

deep absorbed dose: the absorbed dose at the depth of 1.0 cm

deep dose equivalent (Hd): the dose equivalent at the respective depth of 1.0 cm in tissue.

detection limit (lower): the minimum quantifiable exposure or flux that can be detected.

dose equivalent (H): the product of the absorbed dose (D), the quality factor (Q), and any other 

modifying factors. The special unit is the rem. When D is expressed in Gy, H is in Sieverts (Sv). 

(1 Sv = 100 rem.)

dose of record: the dose files provided by DOE to NIOSH as part of an individual worker’s files. 

dosimeter: a device used to measure the quantity of radiation received. A holder with radiationabsorbing elements (filters) and an insert with radiation-sensitive elements packaged to provide a 

record of absorbed dose or dose equivalent received by an individual.
Effective Date: 02/09/2004 Revision No. 00 Document No. ORAUT-TKBS-0011-3 Page 24 of 27

dosimetry: the science of assessing absorbed dose, dose equivalent, effective dose equivalent, 

from external and/or internal sources of radiation. 

dosimetry system: a system used to assess dose equivalent from external radiation to the whole 

body, skin, and/or extremities. This includes the fabrication, assignment, and processing of the 

dosimeters as well as interpretation and documentation of the results.

exchange period (frequency): time period (weekly, biweekly, monthly, quarterly, etc.) for routine 

exchange of dosimeters.

exposure: expressed in roentgens (R): the ionization produced by photon (gamma and x-rays) 

radiation in air. 

extremities: elbow through fingers; knee through toes.

field calibration: dosimeter calibration based on radiation types, intensity and energies present 

in the work environment.

film: generally means a film packet that contains one or more pieces of film in a light-tight 

wrapping. The film when developed has an exposure, caused by radiation, that can be measured 

using an optical densitometer.

film density: SEE optical density.

film dosimeter: a small packet of film within a holder.

fission: the splitting of an atomic nucleus, accompanied by the release of energy.

fissionable: material capable of undergoing fission (Pu-239, U-235, U-233).

flux, neutron (n/cm2

-sec): a measure of the intensity of radiation in neutrons/cm2-sec. It is the

number of neutrons passing through 1 square centimeter in 1 second. 

gamma rays: ionizing electromagnetic radiation (photons) originating from atomic nuclei. 

gray: the international system unit of absorbed dose.

HEPA filter: high efficiency particulate air filter; a dense, corrugated filter capable of removing a 

high percentage of particulate material from an air flow

HEU: highly enriched uranium

hydrofluorination: chemical conversion to a form containing fluorine.

ionizing radiation: electromagnetic or particulate radiation capable of producing charged 

particles through interactions with matter.

isotope: elements having the same atomic number but different atomic weights; identical 

chemically but having different physical and nuclear properties 

lumbrosacral spine: the five lumbar and five sacral vertebrae of the spine.
Effective Date: 02/09/2004 Revision No. 00 Document No. ORAUT-TKBS-0011-3 Page 25 of 27

maximum permissible body burden (MPBB): whole body activity limit for a radionuclide.

maximum permissible lung burden, Pu (MPLB): the occupational limit for Pu; quantity of

plutonium allowed in the chest at any given time.

minimum detectable activity (MDA): limit of detection for measurements; specific to types and 

energies of radiation and radioactive materials.

near-net shape: close to final shape.

neutron: neutral nuclear particle; mass nearly the same as the proton.

neutron, fast: neutrons with energy equal or greater than 10 keV.

neutron, intermediate: neutrons with energy between 0.5 eV and 10 keV.

neutron, thermal: neutrons in thermal equilibrium with surroundings. Generally, neutrons with 

energy less than about 0.5 eV.

neutron film dosimeter: a film dosimeter that contains an Neutron Track Emulsion, type A, film 

packet.

Nuclear Emulsion: often referred to as “NTA” film and used to measure personnel dose from 

neutron radiation.

Nuclear Track Emulsion, Type A (NTA): a film that is sensitive to fast neutrons. The developed 

image has tracks caused by neutrons that can be seen by using appropriate imaging capability.

open window (OW): designation on film dosimeter reports that implies the use of little (i.e., only 

security credential) shielding. 

operating area: designation of major operational work areas onsite.

optical density: the quantitative measurement of photographic blackening: density defined as D 

= Log10 (Io/I).

pencil dosimeters: a type of ionization chamber used by personnel to measure radiation dose. 

Used by visitors or under other conditions of short-term exposure where data should be evaluated 

immediately. Results may be labeled as “Pen” dose. Other names: pencil, pocket dosimeter, 

pocket pencil, pocket ionization chamber.

personal dose equivalent Hp(d): represents the dose equivalent in soft tissue below a specified 

point on the body at an appropriate depth d. The depths selected for personnel dosimetry are 

0.07 mm and 10 mm, respectively, for the skin and body. These are noted as Hp(0.07) and 

Hp(10), respectively. 

photon: a unit or "particle" of electromagnetic radiation consisting of x- and/or gamma rays. 

photon (ionizing): x- or gamma radiation. 
Effective Date: 02/09/2004 Revision No. 00 Document No. ORAUT-TKBS-0011-3 Page 26 of 27

photon - x-ray: electromagnetic radiation of energies between 10 keV and 100 keV whose 

source can be x-ray machine or radioisotope.

pit: nuclear weapon core, made of fissionable material

quality factor, Q: a modifying factor used to derive dose equivalent from absorbed dose.

radiation: alpha, beta, neutron, x- or gamma radiation. 

radioactivity: the spontaneous emission of radiation from unstable nuclei.

radionuclide: a radioactive isotope of an element, identified by atomic number and atomic weight

relative biological effectiveness (RBE): a ratio of absorbed dose of a reference radiation to 

absorbed dose of a other radiation producing the same biological effects

rem: the rem is a unit of dose equivalent, equal to the product of the number of rads absorbed 

and the quality factor.

rep: roentgen-equivalent-physical (mrep = millirep) used when reporting beta exposures.

Roentgen (R or r): a unit of exposure to gamma (or x-) radiation. It is defined as the quantity of 

gamma (or x) rays that will produce a total charge of 2.58 x 10-4 coulomb in 1 kg of dry air. An 

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

(~>100 keV) energy photons.

shallow absorbed dose (Ds): the absorbed dose at a depth of 0.007 cm in a material of 

specified geometry and composition.

shallow dose equivalent (Hs): dose equivalent at a depth of 0.007 cm in tissue.

shielding: any material or obstruction that or attenuates radiation and thus can protect personnel 

or materials from radiation.

sievert (Sv): the SI unit for dose equivalent. (1 Sv = 100 rem.)

silver shield(s): the 1-mm thick shields covering a portion of the film packet in early film 

dosimeters. 

site returns: weapons components retired and returned for disassembly and recovery of materials

skin dose: absorbed dose at a tissue depth of 7 mg/cm2

. 

Snoopy: portable neutron monitoring instrument with a moderated BF3 detector.

thermoluminescent: property of a material that causes it to emit light as a result of being excited 

by heat.

thermoluminescent dosimeter (TLD): a holder containing solid chips of material that when 

heated will release, as light, energy stored during interaction with ionizing radiation. The 

measurement of the emitted light is proportional to absorbed dose. 
Effective Date: 02/09/2004 Revision No. 00 Document No. ORAUT-TKBS-0011-3 Page 27 of 27

transuranic: an element with an atomic number greater than uranium (92); all transuranic 

elements are radioactive and are produced artificially.

trigger: fissionable core of nuclear weapon, also used to trigger fusion energy release

whole body dose: commonly defined as the absorbed dose at a tissue depth of 1.0 cm (1000 

mg/cm2

); however, this term is also used to refer to the recorded dose.

x-ray: ionizing electromagnetic radiation produced outside the nucleus.