ORAU TEAM

Dose Reconstruction

Project for NIOSH

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

Page 1 of 20

Document Title:

A Standard Methodology for 

Overestimating External Doses Measured 

with Thermoluminescent Dosimeters 

Document Number: ORAUT-OTIB-0008

Revision: 01

Effective Date: 05/12/2006

Type of Document: OTIB

Supersedes: Revision 00

Subject Experts: Jack J. Fix and Donald N. Stewart

Document Owner

Approval: Signature on File Approval Date: 05/04/2006

John M. Byrne, Task 3 Manager

Concurrence: Signature on File Concurrence Date: 05/11/2006

Kate Kimpan, Project Director

Approval: Signature on File Approval Date: 05/12/2006

James W. Neton, Associate Director for Science

 New Total Rewrite Revision Page Change

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

REVISION AND DISCARD / DESTROY ALL COPIES OF THE PRIOR REVISION.
Document No. ORAUT-OTIB-0008 Revision No. 01 Effective Date: 05/12/2006 Page 2 of 20

PUBLICATION RECORD

EFFECTIVE 

DATE

REVISION 

NUMBER DESCRIPTION

11/07/2003 00 New document to establish Technical Information Bulletin for 

Overestimating External Doses Measured with Thermoluminescent 

Dosimeters. First approved issue. Initiated by Jack J. Fix.

05/12/2006 01 Revised document as a result of biennial review. Constitutes a total 

rewrite of document. Approved Revision 01. Training required: As 

determined by the Task Manager. Initiated by Jack J. Fix and 

Donald N. Stewart.
Document No. ORAUT-OTIB-0008 Revision No. 01 Effective Date: 05/12/2006 Page 3 of 20

TABLE OF CONTENTS

SECTION TITLE

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

PAGE

5

1.0 Introduction ..............................................................................................................................6

1.1 Objectives ........................................................................................................................7

2.0 Complex-Wide Standard Overestimating Methodology ............................................................ 8

2.1 Overestimating Applied to Recorded Dose.......................................................................8

2.2 Overestimating Applied to Organ Dose Conversion Factor...............................................9

2.3 Overestimating Applied to Missed Dose...........................................................................9

2.4 Application of Standard Overestimating Assumptions ....................................................10

References ........................................................................................................................................12

Appendix A, Technical Basis for Recommendations..........................................................................14

A.1 Dosimetry Development and Basis of Comparison................................................................. 14

A.1.1 Dosimetry Development.............................................................................................. 14

A.1.2 Basis of Comparison................................................................................................... 14

A.2 Dose Reconstruction Parameters........................................................................................... 15

A.2.1 Dosimetry Technology ................................................................................................ 15

 A.2.1.1 Potential Missed Dose................................................................................... 16

 A.2.1.2 Site-Specific Thermoluminescent Dosimeter................................................. 16

 A.2.1.3 Commercial TLD ........................................................................................... 17

A.2.2 Calibration ..................................................................................................................17

A.2.3 Dosimeter Performance Studies ................................................................................. 18

A.3 Site-Specific Information ........................................................................................................ 19

A.3.1 Workplace Radiation Fields ........................................................................................ 19

A.4 Summary of Overestimation Implicit in the Standard Overestimating Assumptions ................ 20
Document No. ORAUT-OTIB-0008 Revision No. 01 Effective Date: 05/12/2006 Page 4 of 20

LIST OF TABLES

TABLE TITLE

2-1 Consolidated results for geometry and calibration method .......................................................

PAGE

8

2-2 Standard overestimating approach......................................................................................... 10

2-3 Periods of applicability for assumptions, by site ..................................................................... 11

A-1 MED/AEC/DOE sites with equivalent beta/photon dosimetry capabilities ............................... 14

A-2 Chronology of DOE site implementation of TLD-based personnel 

dosimetry systems ................................................................................................................. 16

A-3 Maximum annual potential missed dose................................................................................. 16

A-4 IARC testing results for U.S. beta/photon dosimeters............................................................. 19

A-5 Testing results for TLDs for energy and angular response ..................................................... 19

A-6 Common workplace photon dosimeter Hp(10) performance ................................................... 20

LIST OF FIGURES

FIGURE TITLE

A-1 Photon energy dependence in comparison with Hp(10)..........................................................

PAGE

17
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ACRONYMS AND ABBREVIATIONS

AEC U.S. Atomic Energy Commission

AP anterior-posterior

CFR Code of Federal Regulations

DCF Dose Conversion Factor

DOE U.S. Department of Energy

DOELAP DOE Laboratory Accreditation Program

INEEL Idaho National Environmental and Engineering Laboratory

Hp(d) Personal Dose Equivalent

keV kilovolt-electron

LANL Los Alamos National Laboratory

LLNL Lawrence Livermore National Laboratory

MDL minimum detection level

MED Manhattan Engineer District

mm millimeter

NTS Nevada Test Site

NVLAP National Voluntary Laboratory Accreditation Program

ORNL Oak Ridge National Laboratory

ORAUT Oak Ridge Associated Universities Team

RFP Rocky Flats Plant

ROT rotational

SRS Savannah River Site

TIB technical information bulletin

TLD thermoluminescent dosimeter

U.S.C. United States Code
Document No. ORAUT-OTIB-0008 Revision No. 01 Effective Date: 05/12/2006 Page 6 of 20

1.0 INTRODUCTION

Technical information bulletins (TIBs) are not official determinations made by the National Institute for 

Occupational Safety and Health (NIOSH) but are rather general working documents that provide 

historic background information and guidance to assist in the preparation of dose reconstructions at 

particular sites or categories of sites. They will be revised in the event additional relevant information 

is obtained. TIBs may be used to assist the NIOSH staff in the completion of individual dose 

reconstructions.

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

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

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

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

EEOICPA defines a DOE facility as “any building, structure, or premise, including the grounds upon 

which such building, structure, or premise is located ... in which operations are, or have been, 

conducted by, or on behalf of, the Department of Energy (except for buildings, structures, premises, 

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

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

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

facility encompassed by EEOICPA.

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

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

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

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

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

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

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

determined in accordance with the POC [probability of causation1

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

premises, grounds, or operations covered by Executive Order No. 12344, dated February 1, 1982 (42 

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

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

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

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

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

exposures at the facility in its dose reconstructions for employees at DOE facilities, including radiation 

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

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

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

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

derived:

] guidelines established under 

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

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

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

• Radiation from naturally occurring radon present in conventional structures

 1 The U.S. Department of Labor is ultimately responsible under the EEOICPA for determining the POC.
Document No. ORAUT-OTIB-0008 Revision No. 01 Effective Date: 05/12/2006 Page 7 of 20

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

The Manhattan Engineer District (MED) and later the U.S. Atomic Energy Commission (AEC) had 

early responsibility for processing nuclear weapons material. The AEC was superseded in this 

function briefly by the Energy Research and Development Agency, and then by DOE. In this 

document, “DOE” is a term of convenience meaning the Department of Energy and its predecessor 

agencies.

Essentially all DOE sites followed a similar evolution in external dosimetry technology. Early twoelement film dosimeters were followed by multielement film dosimeters, and thermoluminescent 

dosimeters (TLDs) replaced film dosimeters from the late 1960s through the early 1980s. Since the 

late 1980s, DOE has required accreditation of personnel dosimetry programs under the DOE 

Laboratory Accreditation Program (DOELAP; DOE 1986a,b) or, for smaller programs, under the 

National Voluntary Laboratory Accreditation Program (NVLAP; Torres 2005). Both of these programs

(DOE 1986b, Torres 2005) involve biennial performance testing based on guidance in American 

National Standards Institute (ANSI) Standard N13.11 (HPS 2001 or an earlier version). Under the 

Energy Employees Occupational Illness Compensation Program Act, dose reconstructors are to use 

personnel doses measured with DOELAP-accredited dosimetry programs (NIOSH 2002).

This Oak Ridge Associated Universities Team (ORAUT) TIB is based on the feasibility for the dose 

reconstructor to apply reasonable, overestimating, complex-wide assumptions for interpreting 

recorded photon dose for monitored workers due to the high degree of standardization of DOE TLDbased programs. In accordance with the process efficiencies discussed in 42 CFR Part 82, the TIB 

analysis selected a reasonable overestimate of external radiation dose for cases that are judged to be 

likely-noncompensable. This overestimate of the actual dose enables the expeditious processing of

likely-noncompensable claims.

1.1 OBJECTIVES

The objectives of this document are to (1) evaluate the degree of standardization of DOE TLD 

measurements and (2) develop a standard methodology that the dose reconstructor will use to assign 

a dose, based on the recorded dose, resulting in a reasonable overestimate of the organ dose. This 

document examines the performance of TLDs and proposes the application of the standard 

methodology to overestimate doses and address uncertainties from the following sources.

• Variation in workplace photon radiation fields

• Variation in workplace exposure geometries

• Variation in worker orientation in the workplace, the organ of concern, and the range of values 

for organ dose conversion factors presented in External Dose Reconstruction Implementation 

Guidelines (NIOSH 2002)

While accounting for these uncertainties, the methodology proposed here takes into account 

similarities among sites throughout the DOE complex in the following attributes:

• Similar dose response performance by photon energies among the TLDs used

• Similar minimum detection levels (MDL)

• A standard exchange frequency
Document No. ORAUT-OTIB-0008 Revision No. 01 Effective Date: 05/12/2006 Page 8 of 20

The proposed methodology considers variability associated with a large number of program features. 

The methodology must admit a greater degree of error into any estimate that it modifies. This error is 

permissible as long as it is in the claimant’s favor. Specifically, any error must tend to assuredly 

overestimate rather than reduce the claimant’s probability of causation.

Because the intent is to overestimate the dose for a quick evaluation of the potential for 

compensability, the proposed methodology is useful only for probable noncompensable claims. 

The use of this methodology will be inappropriate for certain organs outside the considered range of 

organ dose conversion factors. For this reason, dose reconstructions for cancers of skin and eye and 

to the bone surface are not to use the claimant-favorable overestimates resulting from the analyses in 

this document. These assumptions also exclude assignment of shallow doses, which precludes dose 

reconstruction for cancers to the skin, testes, or breast.

2.0 COMPLEX-WIDE STANDARD OVERESTIMATING METHODOLOGY

Three components of the standard methodology to overestimate the organ dose assigned to a 

claimant for a likely-noncompensable claim are:

• Recorded dose

• Dose Conversion Factor (DCF)

• Missed dose

Recommendations are provided in the following with supporting information presented in Appendix A. 

2.1 OVERESTIMATING APPLIED TO RECORDED DOSE

This TIB recommends a standard overestimating approach that, with a single modifying value applied 

to the recorded dose, increases the assigned dose to claimants to overestimate the actual Hp(10) 

dose. The purpose of this modifying factor is to ensure claimant-favorable assigned organ dose for 

potential site-specific exposure conditions and calibration practices that, without correction, could

result in an underestimated dose.

This modifying factor provides a simple option for evaluation of likely-noncompensable claims. The 

dose reconstructor multiplies the recorded dose by the standard modifying factor to overestimate the 

actual dose. This factor must be sufficiently high to compensate for variance in dosimeter 

performance among sites and to take into account corrections that might be required to convert the 

dose as measured from site to site to a standard value of Hp(10). Table 2-1 lists values of factors that 

would correct for variations in calibration and site-specific workplace conditions.

Correction of each of these values would require application of factors with a value over the range of 

0.87 to 1.22. The highest 95% uncertainty factor in Fix, Gilbert, and Baumgartner (1994) was 1.3, or 

for the range in reported dose for the beams examined compared to Hp(10) of 0.7 (0.87/1.3) to 1.6 

(1.22 × 1.3). Greater uncertainty is expected at lower photon energies. However, for most 

workplaces and longer term workers, the measured dose at levels sufficiently greater than the MDL 

will probably closely estimate Hp(10) without modification and reasonably estimate exposure to the 

worker. 

Table 2-1. Consolidated results for geometry and calibration method 

(from Tables A-3 and A-4).

Irradiation Geometry/phantom Ratio of reported dose to given 
Document No. ORAUT-OTIB-0008 Revision No. 01 Effective Date: 05/12/2006 Page 9 of 20

Hp(10) by photon energy (keV)a

70 118,b 120c 208 662

AP Slab 1.1 1.1 1.1

AP, 72-83 Anthropomorphic 1.05 0.96 1.1

AP, 84-94 Anthropomorphic 0.95 0.87 1.0

Rotational Anthropomorphic 1.1 1.2 1.0

Rot, 72-83 Anthropomorphic 1.17 1.14 1.22

Rot, 84-94 Anthropomorphic 1.06 1.03 1.11

Isotropic Anthropomorphic 0.9 1.0 0.9

Average 1.06 1.01 1.1 1.06

a. Values have been modified from response ratios (in parentheses) to multiplicative 

correction factors.

b. Thierry-Chef et al. (2002)

c. Wilson et al. (1990)

2.2 OVERESTIMATING APPLIED TO ORGAN DOSE CONVERSION FACTOR

This TIB recommends a standard overestimating organ DCF. Use the DCF to calculate the organ 

dose by multiplying the recorded deep dose value by the DCF. The value of the DCF represents an 

additional source of variation.

For organ dose reconstruction, photon doses are divided into three groups of energies: less than 

30-keV photons, photons with energies between 30 and 250 keV, and photons with energies greater 

than 250 keV. The maximum values of the photon DCFs (DCFmax) listed in NIOSH (2002) were 

evaluated for these three energy ranges for all organs except the eye, skin, testes, breast, and bone 

surface. The value of the maximum DCF varies from a low of 0.154 (photons of energies less than 30 

keV to the red bone marrow) to a maximum of 1.066 (photons of energies greater than 250 keV to the 

thyroid). A value of 1.100, rounded for simplicity, captures the few values greater than unity while 

overestimating the organ dose in relation to the majority of the listed DCFs.

2.3 OVERESTIMATING APPLIED TO MISSED DOSE

This TIB recommends a standard overestimating approach to determining the missed dose. The 

consistency of intersite comparison of levels of detection suggests a standard value for missed dose 

of 0.020 rem per dosimeter reading (see Appendix A). This factor is based on laboratory testing, and 

it is not known how this might be reflected in MDLs for dosimeters in operational use in the workplace. 

To ensure a claimant-favorable approach, increase the assumed value for missed dose to 0.030 rem 

in the absence of site-specific information. This value is twice the value for missed dose for TLDs in 

use at the SRS, and six times the missed dose for DOELAP-approved TLDs; the value is 50% greater 

than the missed dose for Hanford site-specific TLDs, and three times the value for missed dose with 

Hanford DOELAP-approved TLDs. The claimant favorability in this overestimate is intended to offset 

the uncertainty in missed dose for early TLDs when the DOELAP testing protocol was not in place. 

Personnel dosimeter performance testing was conducted for many years prior to DOELAP (Roberson 

et al. 1983; Unruh et al. 1967; Gorson, Suntharalingam, and Thomas 1965) and was the subject of an 

AEC notice in 1963 (AEC 1963). Assume an exchange period of monthly (see Appendix A) and 

calculate an overestimate of the missed dose by applying the MDL to all badge cycles (i.e., 360 

mrem). 

Standard assumption for dosimeter exchange frequency: The transition of the early film badge 

exchange frequency to at least a monthly exchange frequency is described in the Site Profiles. Most 

sites had changed to a standard monthly and/or quarterly exchange frequency by the time TLD use 

began. Thus, for the period of applicability of the assumptions in this TIB, badge exchange 
Document No. ORAUT-OTIB-0008 Revision No. 01 Effective Date: 05/12/2006 Page 10 of 20

frequencies are assumed to be monthly although the actual exchange period should be considered 

from the Site Profile. 

2.4 APPLICATION OF STANDARD OVERESTIMATING ASSUMPTIONS

Table 2-2 summarizes standard values for the correction factors recommended in Sections 2.1 

through 2.3. A combined standard overestimating approach of 2 is obtained for the combined effects 

of the recorded dose modifying factor and the maximum DCF (i.e., 1.6 × 1.1 = 1.76 for the 95% 

uncertainty or, to account for greater than 95% uncertainty and simplicity, a factor of 2.00). This 

single value can be applied to all deep doses reported by DOE sites to arrive at a claimant-favorable 

estimate of the dose to any organ except the eye, skin, testes, breast and bone surface. In addition, it 

is not appropriate to apply estimates of uncertainty after the application of overestimating 

assumptions. Additional doses from reported shallow dose would need to be evaluated separately, as 

applicable, depending on the organ of interest. 

Table 2-2. Standard overestimating approach.

Parameter Analysis Standard overestimating approach

Recorded dose Multiply by 1.6 Multiply recorded deep dose by factor of 

DCF DCF = 1.1 two and enter as constant value in IREP

Missed dose Zero recorded dose Lognormal distribution, 

IREP parameter #1 = MDL/2 = 0.18a rem

IREP parameter #2 = 1.52

a. Use TBD identified value, if available. Otherwise use this value based on n*LOD, where n = 12. 

Dose reconstructors should apply the values in Table 2-2 based on the period of applicability for the 

site in question from the date of first use of TLDs through the DOELAP-accredited periods, when 

Hp(10) equivalency is expected. The dates listed in Table 2-3 reflect the dates after which dose 

reconstructors can apply the assumptions in this TIB. The entries for INEEL and RFP are later than 

the date of TLD first use due to the potential unreliability of correction factors prior to 1970. Most sites 

implemented TLDs in the 1970s, as noted in Appendix A. The response characteristics of early TLDs 

(prior to 1970 unless specified in Table 2-3) require further evaluation and are therefore excluded.
Document No. ORAUT-OTIB-0008 Revision No. 01 Effective Date: 05/12/2006 Page 11 of 20

Table 2-3. Periods of applicability for 

assumptions, by site.

Site

Apply assumptions from listed 

year (year of first use of TLDs)

Fernald 1985

Hanford 1972

INEEL 1970

K-25 1980

LANL 1980

LLNL 1969

Mound 1977

NTS 1979

ORNL 1974

Pantex 1973

Portsmouth 1981

RFP 1971

SRS 1970

Y-12 1980
Document No. ORAUT-OTIB-0008 Revision No. 01 Effective Date: 05/12/2006 Page 12 of 20

REFERENCES

AEC (U.S. Atomic Energy Commission), 1955, “Intercomparison of Film Badge Interpretations,” 

Isotopics, volume 2, number 5, pp. 8–23.

Barber, D. E., 1967, Standards of Performance for Film Badge Services, Public Health Service 

Publication No. 999-RH-20, U.S. Government Printing Office, Washington, D.C.

Becker, K., 1973, Solid State Dosimetry, CRC Press, Cleveland, Ohio.

Brodsky, A., and R. L. Kathren, 1963, “Accuracy and Sensitivity of Film Measurements of Gamma 

Radiation - Part 1,” Health Physics, volume 9, pp. 453–461.

Chabot, G. E. Jr., M. A. Jimenez, and K. W. Skrable, 1978, “Personnel Dosimetry in the U.S.A.,” 

Health Physics, volume 34, number 4, pp. 311–321.

Cummings, R., 2003, “Results of a Study to Determine the Impact of the New Dosimetry Performance 

Standard, N13.11-2001,” Health Physics, volume 84, number 3, pp. 296–306.

DOE (U. S. Department of Energy), 1986, Department of Energy Standard for the Performance 

Testing of Personnel Dosimetry Systems, DOE Laboratory Accreditation Program for 

Personnel Dosimetry Systems, DOE/EH-0027, Assistant Secretary for Environment, Safety, 

and Health, Washington, D.C., December.

DOE (U.S. Department of Energy), 1986, Handbook for the Department of Energy Laboratory 

Accreditation Program for Personnel Dosimetry Systems, DOE/EH-0026, Assistant Secretary 

for Environment, Safety, and Health, Washington, D.C., December.

Fix, J. J., E. S. Gilbert, and W. V. Baumgartner, 1994, An Assessment of Bias and Uncertainty in 

Recorded Dose from External Sources of Radiation for Workers at the Hanford Site, PNL10066, Battelle Memorial Institute, Pacific Northwest Laboratory, Richland, Washington, 

August.

Fix, J. J., R. H. Wilson, and W. V. Baumgartner, 1997, Retrospective Assessment of Personnel 

Neutron Dosimetry for Workers at the Hanford Site, PNNL-11196, Battelle Memorial Institute, 

Pacific Northwest National Laboratory, Richland, Washington, February.

Gorson, R. O., N. Suntharalingam, and J. W. Thomas, 1965, "Results of a Film-Badge Reliability 

Study," Radiology, volume 84, pp. 333–346.

Hine, G. J., and G. L. Brownell, editors, 1956, Radiation Dosimetry, Academic Press, New York, New 

York.

HPS (Health Physics Society), 2001, An American National Standard, Personnel Dosimetry 

Performance – Criteria for Testing, ANSI/HPS N13.11-2001, McLean, Virginia.

ICRU (International Commission on Radiation Units and Measurements), 1993, Quantities and Units 

in Radiation Protection Dosimetry, Report 51, Bethesda, Maryland.
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NIOSH (National Institute for Occupational Safety and Health), 2002, External Dose Reconstruction 

Implementation Guideline, OCAS-IG-001, Rev. 1, Office of Compensation Analysis and 

Support, Cincinnati, Ohio, August.

Pardue, L. A., N. Goldstein, and E. O. Wollan, 1944, Photographic Film As a Pocket Radiation 

Dosimeter, CH-1553-A-2223, University of Chicago, Metallurgical Laboratory, Chicago, Illinois,

April.

Parker, H. M., 1945, Comparison of Badge Film Readings at the Metallurgical Laboratories, Clinton 

Laboratories and the Hanford Engineer Works, HW-7-3090, Hanford Atomic Products 

Operation, Richland, Washington, December 7.

Roberson, P. L., K. L. Holbrook, R. C. Yoder, R. A. Fox, R. T. Hadley, B. T. Hogan, and C. D. Hooker, 

1983, Performance Comparisons of Selected Personnel Dosimetry Systems in Use at 

Department of Energy Facilities, PNL-3983, Battelle Memorial Institute, Pacific Northwest 

Laboratory, Richland, Washington, October.

Thierry-Chef, I., F. Pernicka, M. Marshall, E. Cardis, and P. Andreo, 2002, "Study of a Selection of 10 

Historical Types of Dosimeter: Variation of the Response to Hp(10) with Photon Energy and 

Geometry of Exposure," Radiation Protection Dosimetry, volume 102, number 2, pp. 101–113.

Torres, B. A., 2005, National Voluntary Laboratory Accreditation Program: Ionizing Radiation 

Dosimetry, Handbook 150-4, U.S. Department of Commerce, National Institute of Standards & 

Technology, Washington, D.C.

Unruh, C. M., H. V. Larson, T. M. Beetle, and A. R. Keene, 1967, The Establishment and Utilization of 

Film Dosimeter Performance Criteria, BNWL-542, Battelle Memorial Institute, Pacific 

Northwest Laboratory, Richland, Washington.

Wilson, R. H., J. J. Fix, W. V. Baumgartner, and L. L. Nichols, 1990, Description and Evaluation of the 

Hanford Personnel Dosimeter Program from 1944 through 1989, PNL-7447, Battelle Memorial 

Institute, Pacific Northwest Laboratory, Richland, Washington, September.
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A.1 DOSIMETRY DEVELOPMENT AND BASIS OF COMPARISON

A.1.1

Radiation response characteristics of dosimetry technology used by the DOE sites are highly similar. 

Most MED sites followed a similar evolution in dosimetry technology from the two-element film 

dosimeter design developed in 1944 (Pardue, Goldstein, and Wollan 1944), the use of multielement 

film dosimeter designs and, later, thermoluminescent dosimetry methods because of the ease of 

automation and nearly tissue-equivalent radiation response to photon radiation. The judgment in this 

TIB is that equivalent performance in dose estimation is achieved with the thermoluminescent 

dosimetry technology used by DOE sites as evaluated in this analysis. This conclusion is based on a 

survey of the Site Profiles listed in Table A-1. 

Dosimetry Development

A.1.2

Since the initiation of the MED in the early 1940s, various radiation dose concepts and quantities have 

been used to measure and record occupational dose. A basis of comparison for reconstruction of 

dose is the Personal Dose Equivalent, Hp(d), where d identifies the depth (in millimeters) and 

represents the point of reference for dose in tissue. For weakly penetrating radiation of significance to 

skin dose, d = 0.07 mm and is noted as Hp(0.07). For penetrating radiation of significance to “wholebody” dose, d = 10 mm and is noted as Hp(10). Both Hp(0.07) and Hp(10) are the radiation quantities 

recommended for use as the operational quantities to be recorded for radiological protection purposes 

by the International Commission on Radiological Units and Measurements (ICRU 1993). In addition, 

Hp(0.07) and Hp(10) are the radiation quantities used in DOELAP and NVLAP dosimeter performance 

testing.

Basis of Comparison

Table A-1. MED/AEC/DOE sites with equivalent beta/photon dosimetry capabilities.

Site Site profile reference

Thermoluminescent 

dosimeter year of first use

Site-specific Commercial

Fernald ORAUT-TKBS-0017-6 N.A. 1985

Hanford ORAUT-TKBS-0006-6 1972 1995

Idaho National Environmental and Engineering 

Laboratory (INEEL) 

ORAUT-TKBS-0007-6 1966 1986

K-25 ORAUT-TKBS-0009-6 1980 1988

Lawrence Livermore National Laboratory (LLNL) ORAUT-TKBS-0035-6 1969 1985

Los Alamos National Laboratory (LANL) ORAUT-TKBS-0010-6 1978 1999

Mound ORAUT-TKBS-0016-6 N.A. 1977

Nevada Test Site (NTS) ORAUT-TKBS-0008-6 1970 1987

Oak Ridge National Laboratory (ORNL) ORAUT-TKBS-0012-6 1974 1988

Pantex Gaseous Diffusion Plant ORAUT-TKBS-0013-6 1973 1980

Portsmouth Gaseous Diffusion Plant ORAUT-TKBS-0015-6 1981 1999

Rocky Flats Plant (RFP) ORAUT-TKBS-0011-6 1969 1983

Savannah River Site (SRS) ORAUT-TKBS-0003 1970 1982

Y-12 ORAUT-TKBS-0014-6 1980 1988

N.A. – not applicable.

ATTACHMENT A

TECHNICAL BASIS FOR RECOMMENDATIONS

Page 1 of 7
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A.2 DOSE RECONSTRUCTION PARAMETERS

Examinations of the beta and photon (X-ray, gamma ray) radiation type, energy, and geometry of 

exposure in the workplace, and the characteristics of the respective dosimeter response are relevant 

to the assessment of bias and uncertainty, respectively, of the original recorded dose in relation to the 

radiation quantity Hp(10). The bias and uncertainty for current DOE dosimetry systems is well 

documented for Hp(0.07) and Hp(10) under the DOELAP. The performance of current dosimeters can 

be compared with performance characteristics of historical dosimetry systems in the same, or highly 

similar, facilities or workplaces.

Overall, the accuracy and precision of original recorded individual worker doses and their 

comparability dose reconstructors should consider in using NIOSH (2002) guidelines depend on the 

following (Fix, Wilson, and Baumgartner 1997):

• Dosimetry technology, which includes the physical capabilities of the dosimetry system, such 

as the response to different types and energies of radiation, in particular in mixed radiation 

fields

• Calibration of the respective monitoring systems and similarity of the methods of calibration to 

sources of exposure in the workplace

• Workplace radiation fields at each site/facility, which can include mixed types of radiation, 

variations in exposure geometries, and environmental conditions

• Administrative practices adopted by each site to calculate and record personnel dose based 

on technical, administrative, and statutory compliance considerations

Each of these dependent factors must be evaluated. For cases requiring a detailed dose estimate, 

the evaluations must be based on an analysis of site-specific information, which is applied to 

formulate a realistic best dose estimate. For likely noncompensable cases, overestimating dose is 

appropriate, so dose reconstructors can use a modifying factor that increases the recorded deep dose 

to account sufficiently for variance in site practices. Identifying an appropriate value for this modifying 

factor is the goal of this document.

A.2.1

Table A-2 lists the history of implementation of TLD-based external dosimetry programs at DOE sites. 

TLDs have technical advantages over earlier film systems because of their near tissue-equivalent 

response and, with proper handling, general insensitivity to many environmental parameters. The 

adequacy of TLD methods to measure radiation dose accurately is determined from response 

characteristics of the dosimetry technology according to the radiation type, energy, exposure 

geometry, etc., as described in later sections. By the time TLDs had become widely used, the 

dosimeter exchange frequency at the sites had become generally standardized to either a monthly or 

quarterly exchange. A monthly exchange cycle for more highly exposed radiation workers was 

typical. Dose reconstructors should use case- or site-specific data when available.

Dosimetry Technology

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Table A-2. Chronology of DOE site implementation of TLD-based personnel 

dosimetry systems.

Facility

Period

Type

DOELAP 

accrediteda Start End

Fernald 1985 Present Commercial Panasonic TLD system 1990

Hanford 1972 1994 Hanford TLD system 1988

1995 Present Commercial Harshaw TLD system

LANL 1978 1998 LANL TLD system 1987

1999 Present Commercial Harshaw TLD system

Mound 1978 Present Commercial Harshaw TLD system 1996

NTS 1979 1986 NTS TLD system ~1987

1987 Present Commercial Panasonic TLD system

ORNL 1975 1980 ORNL TLD system 1989

1981 1988 ORNL TLD system

1989 Present Commercial Harshaw TLD system

Pantex Plant 1973 1979 Pantex TLD system 1993

1980 Present Commercial Panasonic TLD system

RFP 1969 1982 RFP TLD system 1991

1983 Present Commercial Panasonic TLD system

SRS 1970 1981 SRS TLD system 1987

1981 Present Commercial Panasonic TLD system

Y-12 1980 1988 ORNL TLD system 1989

1989 Present Commercial Harshaw TLD system

a. Year of first successful DOELAP performance testing.

Table A-3. Maximum annual potential missed dose.

Dosimeter type

Exchange 

frequency

Laboratory 

MDL (rem)a Max. annual missed dose (rem)b

Site-specific TLDs Monthly (n = 12) 0.02 0.24

Quarterly (n = 4) 0.02 0.08

Commercial TLDs Monthly (n = 12) 0.01 0.12

Quarterly (n = 4) 0.01 0.04

a. Estimated MDL based on site practice. Dose values less than the MDL are often 

recorded.

b. Maximum annual missed dose based on NIOSH (2002).

A.2.1.1 Potential Missed Dose

A consideration in the analysis of this TIB concerns the estimation of missed dose based on NIOSH 

(2002). Table A-3 summarizes information concerning the estimated maximum potential missed dose 

for personnel thermoluminescent beta/photon dosimeter estimated reasonable MDLs for monthly and 

quarterly exchange frequencies. MDLs for DOE site TLD systems are identified in the respective site 

external dosimetry documentation using the DOELAP laboratory testing protocol (DOE 1986b).

A.2.1.2 Site-Specific Thermoluminescent Dosimeter

TLD systems replaced the multielement film dosimeters at essentially all DOE sites. These systems 

had nearly tissue-equivalent response characteristics. This is particularly evident when compared to

earlier film dosimeter response characteristics. Figure A-1 shows the energy dependence of the 

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widely used lithium fluoride-based (i.e., Harshaw) and lithium borate-based (i.e., Panasonic) TLDs in 

comparison with Hp(10). The relatively close tissue-equivalent response is representative of the site 

TLD systems.

A.2.1.3 Commercial TLD

As listed in Table A-1, the DOE sites proceeded to implement commercial dosimetry systems that 

were generally highly comparable in performance with the site-specific TLD systems and with each 

other. DOE site-specific and commercial TLD systems became accredited under DOELAP and 

0.1

1

10

10 100 1000

Photon Energy, keV

Relative Response

lithium fluoride

lithim borate

Hp(10)

Figure A-1. Photon energy dependence in comparison with Hp(10)

(adopted from Becker 1973).

NVLAP, respectively, beginning in the mid- to late 1980s. These systems have been routinely 

reaccredited during subsequent, typically 2-year, accreditation cycles.

A.2.2

The international adoption of the roentgen as a measure of the radiation quantity exposure in 1928 

provided a means to compare national standards laboratory capabilities to measure exposure from 

photon radiation and a means to standardize a dosimeter response to beta radiation (i.e., in reference 

to the response from radium or X-rays). Agreement between the standard ionization chambers of 

several national laboratories to selected photon beams within ±1% was established in 1931 (Hine and 

Brownell 1956, p. 506). MED site calibration capabilities were based on the national standards 

laboratories, and these capabilities were used to calibrate dosimetry systems, beginning with 226Ra 

and later with 137Cs and 60Co gamma radiation. The basic calibration of DOE dosimetry systems to 

higher energy photons is probably within a variance of a few percent. Parker (1945) demonstrated 

the basic capability for the Metallurgical Laboratory, ORNL, and Hanford sites to calibrate their 

dosimetry systems in 1944 to 226Ra; this is indicative of the basic capability of sites to calibrate their 

dosimetry systems to higher energy photon radiation.

Calibration

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The potential error in recorded dose depends not only on the higher energy photon response of the 

dosimetry technology but also on exposure characteristics for each radiation type, energy, and 

geometry present in the workplace. The similarity between the radiation fields used for calibration and 

those in the workplace is a significant issue. A significant advantage of TLDs over earlier film 

dosimeters is the near tissue-equivalent response of thermoluminescent materials in DOE TLD 

systems. 

A.2.3

Performance testing of personnel dosimetry systems is typically an ongoing activity of the dosimetry 

service provider and a routine component of dosimeter processing quality control. Well-documented 

independent performance studies of personnel dosimeters have been conducted by the AEC (1955), 

Brodsky and Kathren (1963), Unruh et al. (1967), the U.S. Public Health Service (Barber 1967), 

Chabot, Jimenez, and Skrable (1978), the NVLAP, DOELAP, Cummings (2003), and Thierry-Chef et 

al. (2002). The earlier studies were specific to film dosimeter performance; the later studies involved 

TLD systems. The combination of these studies involved many laboratories and dosimetry systems. 

For example, the Public Health Service study involved approximately 2,000 film badges from 25 

organizations (Barber 1967). The DOELAP and NVLAP dosimeter performance testing programs 

initiated in the mid-1980s involve essentially all dosimeter service organizations in the United States. 

Performance testing is typically repeated every 2 years to maintain DOELAP or NVLAP accreditation.

Dosimeter Performance Studies

A simple representation of the measured performance in these studies of dosimeter systems, in the 

categories of testing, is probably not possible. In addition, it is not possible to represent generally the 

improved performance associated with the ongoing evolution in dosimetry technology. National 

Sanitation Foundation Standard No. 16 (Barber 1967) presented upper and lower error factor limits 

that ranged from about 30% low to about 100% high (i.e., an asymmetric interval that is biased high) 

for beta and photon (X-ray and gamma) fields, and mixtures of beta and photon radiation. NVLAP 

and DOELAP testing protocols have varied somewhat, but fundamentally contain a tolerance criterion 

of bias plus one standard deviation between 0.3 and 0.5 (relative error) in routine beta, photon, and 

mixed beta/photon test and accident categories determined for 15 test dosimeters submitted in 

monthly exchanges of 5 dosimeters per test category for a 3-month period.

In addition to the independent performance testing studies for which the identity and performance of a 

laboratory are not available, many sites conducted intercomparison studies of dosimeter capabilities 

using laboratory and workplace irradiations. Wilson et al. (1990) summarized several such studies 

involving Hanford and other site (ORNL, LANL, SRS) dosimeters in laboratory and workplace 

exposures. In addition, many sites processed extensive internal control (i.e., blank or background and 

irradiated), calibration, and audit dosimeters with the personnel dosimeters. The results were 

routinely used to assess the acceptability of overall performance. In addition, several sites routinely 

evaluated worker measured doses using pocket ionization chambers, portable radiation detection 

instruments, and dosimeters. If there were inconsistencies, written evaluations were performed.

In recent years, further studies of early dosimeter performance compared to Hp(10) have been made 

because of the use of recorded dose in worker health effect studies. The International Agency for 

Research on Cancer (IARC) conducted a dosimeter intercomparison study to higher energy (i.e., 

greater than 100 keV) photons of 10 historical dosimetry systems commonly used throughout the

world (Thierry-Chef et al. 2002). The IARC study considered that exposure to dosimeters worn by 

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workers could be characterized as anterior-posterior (AP), rotational (ROT), and isotropic irradiation 

geometries, or a combination thereof. Dosimeter response to selected photon energies was 

measured using two phantoms, which simulated the effect of the worker’s body on the measured 

dosimeter response. The first was the International Standards Organization water-filled slab 

phantom, which is used for dosimeter calibration and performance testing. The second was an 

anthropomorphic Alderson Rando Phantom, which is constructed from a natural human skeleton cast 

inside material that has a tissue-equivalent response. Table A-4 lists results for the SRS commercial 

TLD that participated in IARC testing. The results for the SRS system are likely to be representative 

of other DOE TLD systems. Table A-5 summarizes results for the Hanford TLD system during 1972–

1983 and 1984–1994 based on information in Fix, Gilbert, and Baumgartner (1994).

A.3 SITE-SPECIFIC INFORMATION

Site-specific information is necessary to develop detailed dose estimates. This is done to evaluate 

the performance of the dosimetry technology in the actual workplace radiation fields and the sitespecific administrative practices regarding use of the dosimeters and practices. This establishes a 

basis to calculate and record occupational dose for individual workers. For likely noncompensable 

cases, however, dose reconstructors can apply a standard overestimating methodology that 

Table A-4. IARC testing results for U.S. beta/photon dosimeters.

a

Geometry Phantom

118 keV 208 keV 662 keV

Mean SD/mean Mean SD/mean Mean SD/mean

US-22 (SRS multielement thermoluminescent dosimeter)

AP Slab 0.9 4.4 0.9 3.9 0.9 3.5

AP Anthropomorphic 0.8 3.1 0.9 2.1 0.9 3.9

Rotational Anthropomorphic 1.1 3.1 1.2 1.5 1.0 4.1

Isotropic Anthropomorphic 0.9 0.3 1.0 2.5 0.9 1.6

a. Ratio of recorded dose to Hp(10).

Table A-5. Testing results for TLDs for energy and angular response.

a,b

Beam energy (keV)

1972–1983 1984–1994

AP Rotational AP Rotational

70 (M150 X-ray) 1.05 (1.3) 1.17 (1.5) 0.95 (1.3) 1.06 (1.5)

120 (H150 X-ray) 0.96 (1.2) 1.14 (1.3) 0.87 (1.2) 1.03 (1.3)

662 (Cs-137) 1.1 (1.2) 1.22 (1.3) 1.0 (1.2) 1.11 (1.3)

a. Judgment based on common dosimeter response characteristics and workplace 

radiation fields.

b. Fix, Gilbert, and Baumgartner (1994) TLD data only listed. Bias factor listed with 

estimated 95% uncertainty factor in parenthesis. Summary data for M150 calculated 

in the same manner as presented in Fix, Gilbert, and Baumgartner for H150 and 

Cs-137 with an increased 95% uncertainty factor as listed in the table.

overestimates dose to account for site-specific variations. Such a methodology is developed in 

Section 5.0.

A.3.1

Table A-6 summarizes common beta/photon personnel dosimeter parameters important to Hp(10)

performance in the workplace. Based on energy response characteristics, DOE TLDs are expected to 

Workplace Radiation Fields

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reasonably measure Hp(10) doses in workplace radiation fields particularly for long-term workers with 

many dosimeter results, which tends to improve the accuracy of dose estimation because potential 

effects from extremes in workplace exposure geometries and radiation fields are minimized. 

Adjustments to dose measured by TLDs is not recommended; however, the biases listed in Table A-6

are of sufficient magnitude that the modifying factor must be sufficiently high to ensure claimantfavorable dose assignment.

Table A-6. Common workplace photon dosimeter Hp(10) performance.

a

Parameter Description Workplace biasb

Exposure 

geometry

Dosimeter systems 

commonly calibrated using 

AP laboratory irradiations

Recorded dose of record probably too low because

dosimeter response is often lower at angles other than AP 

in comparison with Hp(10) for AP exposure geometry for 

common practice to use AP dosimeter calibrations. Effect 

is highly dependent on radiation type and energy.

Missed dose Doses less than MDL 

recorded as zero dose

Recorded dose of record probably too low.

Environmental 

effects

Workplace heat, humidity, 

etc., fade dosimeter signal

Recorded dose of record probably too low.

a. Judgment based on common dosimeter response characteristics and workplace radiation fields.

b. Recorded dose compared to Hp(10).

A.4 SUMMARY OF OVERESTIMATION IMPLICIT IN THE STANDARD OVERESTIMATING 

ASSUMPTIONS

Site-specific correction factor: TLD photon energy response typically shows a near tissue

equivalence. For most workplace conditions, a value of a modification factor at or near unity would be 

appropriate. By correcting to the most limiting case (a rotational geometry at a low energy of 70 keV), 

Hp(10) is overestimated by as much as approximately 80%.

Standard organ dose conversion factor: For the organs considered under this set of assumptions, 

DCFs from the Implementation Guide are somewhat less than 1 with two exceptions, the testes and 

the thyroid. An assumed organ DCF of 1.100 would overestimate dose received by the organ by a 

very small amount for these two organs, but by a larger factor for most organs. The standard 

overestimating organ DCF of 2.0 further increases the margin of claimant favorability.

Standard level of missed dose: For all cases processed in accordance with this TIB, the assumed 

value for missed dose is 0.030 rem. This value is high for DOELAP-accredited dosimetry programs. 

For example, the level-of-detection value for ORNL is 0.010 rem for 1981 to the present. Application 

of the standard value here results in an overestimate of 200%, or an annual value of 0.360 rem in a 

year when no dose is recorded for ORNL cases.

Standard badge exchange frequency: DOE sites began in the early to mid-1950s using less 

frequent dosimeter exchanges, lowering missed doses. Personnel who typically received little dose 

would normally be assigned quarterly or even, at some sites, annual TLD exchange frequencies. 

Applying a standard badge monthly exchange frequency overestimates missed dose for workers at 

these sites by assigning them, in the example for ORNL above, 0.360 rem in missed dose, when a 

more accurate missed-dose value based on actual exchange frequencies is 0.120 or 0.030 rem, 

respectively, for the assumed MDL.

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