Draft 

ADVISORY BOARD ON 

RADIATION AND WORKER HEALTH 

National Institute for Occupational Safety and Health 

DRAFT REVIEW OF ORAUT-OTIB-0055: 

TECHNICAL BASIS FOR CONVERSION FROM NCRP REPORT 38 NEUTRON 

QUALITY FACTORS TO ICRP PUBLICATION 60 RADIATION WEIGHTING 

FACTORS FOR RESPECTIVE IREP INPUT NEUTRON ENERGY RANGES 

Contract No. 200-2009-28555

SCA-TR-PR2013-0055, Revision 0 

Prepared by 

Stephen F. Marschke 

Karene Riley 

S. Cohen & Associates 

1608 Spring Hill Road, Suite 400 

Vienna, VA 22182 

January 2013 

Disclaimer 

This document is made available in accordance with the unanimous desire of the Advisory Board on 

Radiation and Worker Health (ABRWH) to maintain all possible openness in its deliberations. However, 

the ABRWH and its contractor, SC&A, caution the reader that at the time of its release, this report is predecisional and has not been reviewed by the Board for factual accuracy or applicability within the 

requirements of 42 CFR 82. This implies that once reviewed by the ABRWH, the Board’s position may 

differ from the report’s conclusions. Thus, the reader should be cautioned that this report is for 

information only and that premature interpretations regarding its conclusions are unwarranted.
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S. COHEN & ASSOCIATES:

Technical Support for the Advisory Board on 

Radiation & Worker Health Review of NIOSH Dose 

Reconstruction Program

Document No. 

SCA-TR-PR2013-0055

Effective Date: 

Draft – January 25, 2013

DRAFT REVIEW OF ORAUT-OTIB-0055: 

TECHNICAL BASIS FOR CONVERSION FROM 

NCRP REPORT 38 NEUTRON QUALITY FACTORS 

TO ICRP PUBLICATION 60 RADIATION 

WEIGHTING FACTORS FOR RESPECTIVE IREP 

INPUT NEUTRON ENERGY RANGES

Page 2 of 19

Task Manager:

________________________ Date: ___________

Stephen F. Marschke

Supersedes:

N/A

Project Manager:

________________________ Date: ___________

John Stiver, MS, CHP

Reviewers:

 John Stiver

 

Record of Revisions

Revision 

Number

Effective 

Date Description of Revision

0 (Draft) 01/25/2013 Initial issue
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TABLE OF CONTENTS 

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

Executive Summary .........................................................................................................................5

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

1.1 Purpose of Technical Information Bulletin ORAUT-OTIB-0055 ...........................6

2.0 ORAUT-OTIB-0055 Review ...............................................................................................7

2.1 Brief History of Neutron Weighting Factors ...........................................................7

2.2 Applied Example ...................................................................................................11

2.3 Review Comments .................................................................................................12

2.3.1 ICRP Publication 103 ................................................................................12

2.3.2 Consistency with OCAS-IG-001 ...............................................................13

3.0 Review Checklist ...............................................................................................................15

3.1 ORAUT-OTIB-0055 Review Checklist ................................................................15

4.0 Conclusion .........................................................................................................................17

References ......................................................................................................................................18

LIST OF TABLES 

Table 2.1-1: ICRP Publication 60 Neutron Weighting Factor .....................................................8

Table 2.1-2: Neutron quality factor, Q, or weighting factor, wR. ..............................................10

Table 2.2-1: Y-12 Neutron Weighting (or Quality) Factor ........................................................11

Table 2.3-1: Neutron Energy Intervals and Associated ICRP 60 Weighting Factor and 

Some Examples of Exposures or Facilities Where the Specific Neutron 

Energy Might be Encountered ...............................................................................14

Table 3.1-1: ORAUT-OTIB-0055 Review Checklist ................................................................15
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ABBREVIATIONS AND ACRONYMS 

ABRWH Advisory Board on Radiation and Worker Health 

CFR Code of Federal Regulations

ICRP International Commission on Radiological Protection 

IREP Interactive Radio Epidemiological Program 

keV kilo electron volt 

MeV million electron volt 

MMES Martin Marietta Energy Systems 

NCRP National Council on Radiation Protection and Measurements 

NIOSH National Institute for Occupational Safety and Health 

NRC U.S. Nuclear Regulatory Commission 

OCAS Office of Compensation Analysis and Support, currently referred to as the 

Division of Compensation Analysis and Support 

OR Oak Ridge 

ORAUT Oak Ridge Associated Universities Team 

PIC pocket ionization chamber 

TIB Technical Information Bulletin 

RBE Relative Biological Effectiveness 

SC&A S. Cohen and Associates (SC&A, Inc.) 

TIB Technical Information Bulletin 

TLD thermoluminescent dosimeter 

wR weighting factor 
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EXECUTIVE SUMMARY 

During its July 31, 2012, meeting, SC&A was tasked by the Advisory Board on Radiation and 

Worker Health (Advisory Board) Subcommittee on Procedures Review to conduct a review of 

ORAUT-OTIB-0055, Technical Basis for Conversion From NCRP Report 38 Neutron Quality 

Factors to ICRP Publication 60 Radiation Weighting Factors for Respective IREP Input Neutron 

Energy Ranges (ORAUT 2006). ORAUT-OTIB-0055 outlines a wider technical basis for 

conversion from recorded neutron dose to dose equivalent using the International Commission 

on Radiological Protection (ICRP) Publication 60 radiation weighting factors. ORAUT-OTIB0055 offers a method that dose reconstructors can utilize to remove the site-specific quality 

factors (Qs) from personal monitoring or radiation survey data at the facility being assessed. 

SC&A’s review of ORAUT-OTIB-0055 is divided into two main parts. The first part reviews 

and summarizes the development of neutron-relative biological effectiveness factors, quality 

factors and radiation weighting factors, and outlines the progression of recommendations 

provided. The second part of the review assesses whether this technical information bulletin 

(TIB) meets objectives to support and provide adequate guidance for dose reconstruction. 

SC&A’s review of ORAUT-OTIB-0055 resulted in the following findings: 

(1) The neutron radiation weighting factors basis for ORAUT-OTIB-0055 (i.e., ICRP 

Publication 60) is outdated; updated scientific recommendations by ICRP have been 

made since ICRP Publication 60. Updated recommendations were published in 2003 

with ICRP Publication 92 (ICRP 2003) and in 2007 with ICRP Publication 103 (ICRP 

2007).

(2) The recommendation provided in ORAUT-OTIB-0055 for selecting the appropriate 

neutron energy is not consistent with the recommendation given in OCAS-IG-001

(OCAS 2007).

(3) NCRP Report 38 was published in 1971 and ORAUT-OTIB-0055 does not present the 

rationale for using NCRP Report 38 as the basis for adjusting pre-1973 neutron 

measurement, rather than NCRP Report 20 (published in 1957), NCRP Report 17 

(published in 1954) or the minutes of the First Tripartite Conference (Taylor 1984).

(4) Table 3-1 in ORAUT-OTIB-0055 presents a neutron quality factor of 3 as the historical 

dosimetry guideline for thermal neutrons. This is inconsistent with the minutes 

documented for the 1949 Tripartite Conference at Chalk River, which presents the 

Relative Biological Effectiveness (RBE) for thermal neutrons as 5, instead of 3. 

Likewise, the preface to NCRP Report 17 (page v) states that an RBE of 5 for thermal 

neutrons is recommended, but no discussion of thermal neutrons was found in the body 

of Report 17. 
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1.0 INTRODUCTION 

This review of ORAUT-OTIB-0055, Technical Basis for Conversion from NCRP Report 38 

Neutron Quality Factors to ICRP Publication 60 Radiation Weighting Factors for Respective 

IREP Input Neutron Energy Ranges (ORAUT 2006), was prepared by SC&A’s Stephen 

Marschke. As with other technical information bulletins (TIBs), ORAUT-OTIB-0055 is a 

working document that provides historical background and guidance information that is used to 

support the development of dose reconstruction at certain sites. TIBs are amended when 

additional pertinent information is obtained and can be used to assist NIOSH staff in dose 

reconstruction. 

1.1 PURPOSE OF TECHNICAL INFORMATION BULLETIN ORAUT-OTIB-0055 

The purpose of ORAUT-OTIB-0055 is to provide “...a broader technical basis to convert from 

recorded neutron dose to dose equivalent using the ICRP Publication 60 radiation weighting 

factors (ICRP 1991).” ORAUT-OTIB-0055 provides a discussion on the need to adjust for the 

neutron dose for each worker to account for the change in neutron quality factors between 

historical and current guidance and recommendations.
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2.0 ORAUT-OTIB-0055 REVIEW 

2.1 BRIEF HISTORY OF NEUTRON WEIGHTING FACTORS

Described below is a brief history of the major documents used in the development of neutronrelative biological effective (RBE) factors, quality factors, and radiation weighting factors. 

Figure 2.1-1 compares the recommended RBE, quality, or radiation weighting factors from the 

documents discussed. ORAUT-OTIB-0055, OCAS-IG-001, and ICRP Publication 92 each 

provide more information on the development of these factors. 

 On September 29 and 30, 1949, the Tripartite Conference was held at Chalk River, 

Canada (Taylor 1984). During the conference, the RBE factors of 5 and 10 for thermal 

(<0.025 keV) and fast (<20 MeV) neutrons, respectively, were agreed to by the 

Committee. 

 On November 22, 1955, the National Committee on Radiation Protection and 

Measurements (NCRP) published Report No. 20 (NCRP 1957). In Report 20, Table 2 

(page 15), the NCRP provides 11 discrete RBE factors for neutrons in the energy range 

from thermal to 10 MeV. For thermal neutrons, an RBE of 3 is recommended; the RBE 

then decreases to 2 at 0.1 keV, before increasing to a maximum of 10.5 at 1 MeV; and 

finally the RBE falls to 6.5 for neutrons of 10 MeV. In Figure 2.1-1 the NCRP 

Report 20-recommended neutron RBEs are shown as the solid green line with solid green 

triangles. 

Figure 2.1-1: Comparison of Neutron Weighting (or Quality) Factors

0

5

10

15

2 0

25

1.E-0 8 1.E-0 7 1.E-0 6 1.E-0 5 1.E-0 4 1.E-0 3 1.E-0 2 1.E-0 1 1.E+00 1.E+01 1.E+02 1.E+03

Weighting (or Quality) Factor

Neutron Energy (MeV)

ICRP 103

ICRP 92

ICRP 60, Formula

ICRP 60, Table 1

NCRP 38

NCRP 20
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 On January 4, 1971, the NCRP published Report No. 38 (NCRP 1971). In Report 38, 

Table 2 (page 16), the NCRP provides 22 discrete mean quality factors for neutrons in the 

energy range from thermal (2.5×10-8 MeV) to 400 MeV. At 1 keV and below, the NCRP 

38-recommended neutron quality factor is 2; the quality factor peaks at 11 for 0.5 to 1 

MeV neutrons before it falls to 3.5 for neutrons at 200 MeV and above. In Figure 2.1-1,

the NCRP Report No. 38-recommended neutron quality factors are shown as the solid 

blue line with solid blue diamonds. 

In 10 CFR §20.1004, Table 1004(b)-2, the Nuclear Regulatory Commission (NRC) still 

requires using the NCRP 38-recommended neutron quality factors. However, when the 

neutron energy is unknown, the NRC requires that a quality factor of 10 be used 

[Table 1004(b)-1].

 In 1991, the International Commission on Radiological Protection (ICRP) issued 

Publication 60 (ICRP 1991). In Publication 60, the ICRP recommends that the neutron 

weighting factors provided in Table 1 of the publication (and reproduced below in 

Table 2.1-1) be used. 

Table 2.1-1: ICRP Publication 60 Neutron Weighting Factor 

Neutron Energy ICRP Publication 60 Neutron Weighting Factor

<10 keV 5

10 keV to 100 keV 10

>100 keV to 2 MeV 20

>2 MeV to 20 MeV 10

>20 MeV 5

ICRP Publication 60 specifically recommends use of the stepwise factors of Table 2.1-1. 

However, to assist in providing consistency in calculations, Publication 60, paragraph 

A12 (page 82), provides the following mathematical relationship between the weighting 

factor (wR) and neutron energy: 

wR = 5 + 17exp(–ln(2En)

2

/6)

Where: wR = The neutron weighting factor

En = Neutron energy

The ICRP cautions that there “is no intention to imply any biological meaning to this 

relationship. It is simply a calculation tool” (ICRP 1991, page 82). In Figure 2.1-1, the 

mathematical relationship is shown by the solid red line with the empty boxes, while the 

stepwise factors are shown by the dashed red line with red stars. 

 In 2003, the ICRP issued Publication 92 (ICRP 2003). In Publication 92, the ICRP 

proposed that the neutron radiation weighting factor (wR) be modified from the factors 

recommended in Publication 60. The proposed modification preserved the weighting 

factor value at 1 MeV, but by being substantially smaller at lower neutron energies, it 

accounted for the large dose contribution from secondary photons at low neutron 

energies. Also, at energies between 1 and 100 MeV, the Publication 92-proposed 
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weighting factors somewhat exceed the Publication 60 values. The Publication 92-

proposed weighting factors are in line with the dependence of the effective quality factor

on neutron energy (ICRP 2003, page 78).

The proposed Publication 92 neutron weighting factors are shown in Figure 2.1-1 as a 

solid light blue line with empty circles, and were based on the following equation taken 

from Publication 92, footnote 9 (page 78).

wR = 2.5[2 – exp(–4En) + 6exp(–ln(En)

2

/4) + exp(–ln(En/30)2/2)]

All parameters have been previously defined.

 In 2007, the ICRP issued Publication 103 (ICRP 2007). In Publication 103, the ICRP 

recommendations shifted from the previous process-based protection approach using 

practices and interventions to an approach based on the exposure situation. The most 

significant changes compared with the data in ICRP Publication 60 (ICRP 1991) are the 

decrease of wR in both the low-energy range and at neutron kinetic energies above 

100 MeV. See Annex B of ICRP Publication 103 for further explanation.

The Publication 103 neutron weighting factors are shown in Figure 2.1-1 as a solid purple 

line with filled circles, and were based on the following equation taken from Publication 

103, equation 4.3 (page 66).

 In 2010, the ICRP published Publication 116 (ICRP 2010). In Publication 116, the ICRP 

presents reference conversion coefficients for effective dose and organ-absorbed doses 

for various types of external exposures that were calculated following ICRP Publication 

103.

wR = {

 

 [ ( )]

 

 

 [ ( )]

 

 

 [ ( )]

 

 

 

 

All parameters have been previously defined.
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Table 2.1-2: Neutron Quality Factor, Q, or weighting factor, wR.

Neutron energy 

(MeV)

Historical dosimetry 

guidelinesa

NCRP Report 38 group 

averaged quality factor b

ICRP Publication 60 

neutron weighting factor Ratioc

Thermal 3 2.35 5 2.13

0.5 eV–10 keV 10

10 keV–100 keV 5.38 10 1.86

100 keV–2 MeV 10.49 20 1.91

2 MeV–20 MeV 7.56 10 1.32

20 MeV–60 MeV 6.96d5 1.00e

a. First Tripartite Conference at Chalk River in 1949 (Taylor 1984) and NCRP Report 17 (NCRP 1954).

b. See ORATU-OTIB-0055, Figure 3-1.

c. Ratio of the ICRP 60 weighting factor to the group averaged NCRP 38 quality factor for each neutron energy 

group.

d. “Not applicable” is usually inserted here rather than the NCRP group averaged value of 6.96, which is larger

than the ICRP 60 weighting factor of 5 for 20-to-60-MeV neutrons and results in a non-claimant-favorable 

reduction in the corrected dose for this neutron energy group.

e. Ratio for adjusting neutron dose from NCRP 38 quality factor to ICRP 60 weighting factor is arbitrarily set 

equal to unity to avoid a non-claimant-favorable reduction in the corrected dose for this neutron energy group.

Finding: Table 2.1-2 provides a neutron quality factor of 3 as the historical dosimetry guideline 

for thermal neutrons. The minutes from the 1949 Tripartite Conference at Chalk River state the 

RBE for thermal neutrons as 5, not 3. Likewise, the preface to NCRP Report 17 (page v) states 

that an RBE of 5 for thermal neutrons is recommended, but no discussion of thermal neutrons 

was found in the body of Report 17.

Finding: NCRP Report 38 was published in 1971. The rationale for using NCRP Report 38 as 

the basis for adjusting pre-1973 neutron measurements, rather than NCRP Report 20 (published 

in 1957), NCRP Report 17 (published in 1954) or the First Tripartite Conference minutes 

(published in 1949) is not presented.
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Figure 2.1-2: Ratio of Neutron Weighting (or Quality) Factors

2.2 APPLIED EXAMPLE

Table 2.2-1 is an example of the difference in the radiation weighting factors between ICRP 60 

and ICRP 103. The dose values calculated using ICRP 60 are higher and therefore claimant 

favorable compared to the dose values calculated using ICRP 103 guidelines.

Table 2.2-1: Y-12 Neutron Weighting (or Quality) Factor

Energy (MeV)

Quality Factor Weighting Factor

Bldg 9212 Bldg 9983 ICRP 60, 

Table 1

ICRP 60, 

Formula ICRP 103

2.57E-07 2.3 2.3 5 5 3

5.48E-07 2.1 2.1 5 5 3

1.06E-06 2.1 2.1 5 5 3

2.25E-06 2.1 2.1 5 5 3

4.77E-06 2.1 2.1 5 5 3

1.01E-05 2.2 2.2 5 5 3

2.14E-05 2.1 2.1 5 5 3

4.52E-05 2.1 2.1 5 5 3

9.58E-05 2.0 2.0 5 5 3

2.03E-04 2.0 2.0 5 5 3

4.34E-04 2.0 2.0 5 5 3

9.13E-04 2.0 2.0 5 5 3

1.92E-03 2.0 2.0 5 5 3

4.07E-03 2.0 2.0 5 5 3

8.62E-03 2.0 2.0 5 6 3

1.82E-02 2.8 2.8 10 8 4

3.86E-02 4.3 4.3 10 11 6

0.0

0.5

1.0

1.5

2.0

2.5

3.0

1.E-0 8 1.E-0 7 1.E-0 6 1.E-0 5 1.E-0 4 1.E-0 3 1.E-0 2 1.E-0 1 1.E+00 1.E+01 1.E+02 1.E+03

Ratio of Weighting (or Quality) Factors

Neutron Energy (MeV)

ICRP 60 / NCRP 38

ICRP 103 / NCRP 38

ICRP 103 / ICRP 60
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Table 2.2-1: Y-12 Neutron Weighting (or Quality) Factor

Energy (MeV)

Quality Factor Weighting Factor

Bldg 9212 Bldg 9983 ICRP 60, 

Table 1

ICRP 60, 

Formula ICRP 103

8.18E-02 6.6 6.6 10 15 9

1.67E-01 8.5 8.5 20 19 13

3.37E-01 10.1 10.0 20 22 17

6.79E-01 10.9 10.9 20 22 20

1.39E+00 9.8 9.9 20 19 19

2.78E+00 8.1 8.2 10 15 15

5.54E+00 7.0 7.0 10 11 11

1.12E+01 6.9 6.9 10 8 8

2.04E+01 6.9 6.9 5 7 7

Total

Bldg 9212 9.9 ─ 18.9 19.7 18.6

Bldg 9983 ─ 7.9 14.2 15.5 14.4

Based on data from NIOSH OR 03-033, “MMES Neutron Field Measurement Data, Y12 Building 9212” and NIOSH OR 03-034, “MMES Neutron Field Measurement 

Data,Y-12 Building 9983” (Wiley 2003)

2.3 REVIEW COMMENTS

2.3.1 ICRP Publication 103

When 42 CFR 82 was published on May 2, 2002, the ICRP recommended the radiation 

weighting factors that are presented in Publication 60 (ICRP 1991), Table 1, as indicated from 

the following excerpt:

The equivalent dose(s) will be calculated using the current, standard radiation 

weighting factors from the International Commission on Radiological 

Protection.1

1

The current weighting factors of the International Commission on Radiological 

Protection are provided in ICRP 60: ‘1990 Recommendations of the International 

Commission on Radiological Protection.’ Ann. ICRP 21 (1–3):6. [42 CFR 

§82.10(j)]

Since 2002, the ICRP has revised its recommendations regarding radiation weighting factors at 

least twice; in 2003 with Publication 92 (ICRP 2003), and in 2007 with Publication 103 (ICRP 

2007). Figure 2.1-1 compares the neutron weighting factors from the three ICRP publications. 

As shown, the most significant differences between the two publications are the decrease of the 

Publication 103 weighting factors in both the low-energy range and at energies above 100 MeV 

compared to the Publication 60 factors.

Finding: The basis for ORAUT-OTIB-0055 (i.e., ICRP Publication 60) is outdated. Since 

ICRP Publication 60 was published, the ICRP has revised its recommendations regarding 

neutron radiation weighting factors, with the latest recommendations being provided in ICRP 
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Publication 103. While SC&A recognizes that ORAUT-OTIB-0055 (effective date June 5, 

2006) predates ICRP Publication 103, notwithstanding issues regarding claimant favorability, we 

believe that NIOSH should consider updating OTIB-0055 to reflect the most recent ICRP 

guidance.

2.3.2 Consistency with OCAS-IG-001

In ORAUT-OTIB-0055, Section 3 “Neutron Dose Equivalent Adjustments” (page 9), the 

following guidance is given on how dose reconstructors should adjust the historical neutron dose 

record to account for the revised neutron weighting factor:

..., dose reconstructors should use the following claimant-favorable 

recommendations in the absence of detailed information on the neutron energies 

involved in a worker’s exposure: (1) assume the corrected neutron dose 

equivalent to be twice the measured dose, missed dose, or dose based on a 

neutron-to-photon ratio, and (2) assume the neutron energies to be in the energy 

range from 0.1 to 2 MeV. [ORAUT 2006, page 9]

The above guidance is repeated in ORAUT-OTIB-0055, Section 4 “Discussion” (page 11). This 

guidance appears to be in contrast with guidance given in OCAS-IG-001, Section 2.2 (OCAS

2007), which states:

When no energy information can be found, the exposure scenarios discussed in 

[Table] can be used to estimate the predominant [neutron] energy.

Finding: The recommendation given in ORAUT-OTIB-0055 for selecting the appropriate 

neutron energy when detailed information on the neutron energies involved in a worker’s 

exposures is not available differs from the recommendation given in OCAS-IG-001 for the same 

scenario.
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Table 2.3-1: Neutron Energy Intervals and Associated ICRP 60 Weighting Factor and 

Some Examples of Exposures or Facilities Where the Specific Neutron Energy Might be 

Encountered

Neutron Energy 

(MeV)

ICRP 60 Weighting 

Factor, wR

Typical Exposure Scenario

< 0.01 5

Low-energy neutron exposures include thermal neutrons commonly 

found around nuclear reactors or moderated neutron sources. More 

prevalent around heavy water reactors.

0.01–0.10 10

Intermediate energy neutron exposures can also result from operation 

around nuclear reactors, as high-energy neutrons are moderated to 

thermal energies.

0.10–2.00 20

Commonly called fission spectrum neutrons, this is the most typical 

energy range from operation of light-water or graphite-moderated 

reactors.

2.0–20.0 10

Reactions between alpha particles from materials such as plutonium or 

polonium and light materials such as beryllium can result in the 

production of neutrons. These reactions are commonly called (α,n) 

reactions. This neutron energy interval also includes 14 MeV neutrons 

from fusion reactions.

> 20.0 5

Exposures to neutrons greater than 20 MeV can result from work around 

accelerators.

Source: OCAS-IG-001, Table 2.2
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3.0 REVIEW CHECKLIST

3.1 ORAUT-OTIB-0055 REVIEW CHECKLIST

Table 3.13.1-1: ORAUT-OTIB-0055 Review Checklist

Document No.: ORAUT-OTIB-0055 Effective Date: 06/05/2006

Document Title: Technical Basis for Conversion from NCRP Report 38 Neutron Quality Factors to ICRP 

Publication 60 Radiation Weighting Factors for Respective IREP Input Neutron Energy Ranges

Auditor: Stephen Marschke

No. Description of Objective Rating 

0–5* Comments

1.0 Determine the degree to which procedures support a process that is expeditious and timely for dose 

reconstruction.

1.1 Is the procedure written in a style that is clear and unambiguous? 5

1.2 Is the procedure written in a manner that presents the data in a logical 

sequence? 5

1.3 Is the procedure complete in terms of required data (i.e., does not 

reference other sources that are needed for additional data)? 4

Inconsistent dose 

adjustment, see 

Section 2.3.2.

1.4 Is the procedure consistent with all other procedures that are part of the 

hierarchy of procedures employed by NIOSH for dose reconstruction? 5

1.5 Is the procedure sufficiently prescriptive in order to minimize the need 

for subjective decisions and data interpretation? 5

2.0 Determine whether the procedure provides adequate guidance to be efficient in instances where a 

more detailed approach to dose reconstruction would not affect the outcome.

2.1 Does the procedure provide adequate guidance for identifying a 

potentially high probability of causation as part of an initial dose 

evaluation of a claim?

N/A

2.2 Conversely, for claims with suspected cumulative low doses, does the 

procedure provide clear guidance in defining worst-case assumptions? N/A

3.0 Assess the extent to which procedures account for all potential exposures and ensure that resultant 

doses are complete and based on adequate data.

3.1 Assess quality of data collected via interviews: -----

3.1.1 Is scope of information sufficiently comprehensive? N/A

3.1.2 Is the interview process sufficiently flexible to permit unforeseen 

lines of inquiry? N/A

3.1.3 Does the interview process demonstrate objectivity, and is it free of 

bias? N/A

3.1.4 Is the interview process sensitive to the claimant? N/A

3.1.5 Does the interview process protect information as required under 

the Privacy Act? N/A

3.2 Adequacy and use of site-specific data pertaining to: -----

3.2.1 Personal dosimeters (e.g., film, TLD, PICs) N/A

3.2.2 In vivo/In vitro bioassays N/A

3.2.3 Missing dosimetry data N/A

3.2.4 Unmonitored periods of exposure N/A
Effective Date:

January 25, 2013

Revision No.

Draft – 0

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NOTICE: This report has been reviewed for Privacy Act information and has been cleared for distribution.

However, this report is pre-decisional and has not been reviewed by the Advisory Board on Radiation and Worker 

Health for factual accuracy or applicability within the requirements of 42 CFR 82.

Table 3.13.1-1: ORAUT-OTIB-0055 Review Checklist

Document No.: ORAUT-OTIB-0055 Effective Date: 06/05/2006

Document Title: Technical Basis for Conversion from NCRP Report 38 Neutron Quality Factors to ICRP 

Publication 60 Radiation Weighting Factors for Respective IREP Input Neutron Energy Ranges

Auditor: Stephen Marschke

No. Description of Objective Rating 

0–5* Comments

4.0 Assess procedure for providing a consistent approach to dose reconstruction regardless of claimants’ 

exposures by time and employment locations

4.1 Does the procedure support a prescriptive approach to dose 

reconstruction? 5

4.2 Does the procedure adhere to the hierarchical process as defined in 42 

CFR 82.2? 5

5.0 Evaluate procedure with regard to fairness and giving the benefit of the doubt to the claimant

5.1 Is the procedure claimant favorable in instances of missing data? 5

5.2 Is the procedure claimant favorable in instances of unknown 

parameters affecting dose estimates? 5

5.3 Is the procedure claimant favorable in instances where claimant was 

not monitored? N/A

6.0 Evaluate procedure for its ability to adequately account for the uncertainty of dose estimates.

6.1 Does the procedure provide adequate guidance for selecting the types 

of probability distributions (i.e., normal, lognormal)? N/A

6.2 Does the procedure give appropriate guidance in the use of random 

sampling in developing a final distribution? N/A

7.0 Assess procedures for striking a balance between technical precision and process efficiency.

7.1 Does the procedure require levels of detail that can reasonably be 

accounted for by the dose reconstructor? 5

7.2 Does the procedure avoid levels of detail that have only limited 

significance to the final dose estimate and its POC? 5

7.3 Does the procedure employ scientifically valid protocols for 

reconstructing doses? 3 See Section 2.3.1

──────────────

* Rating system of 1 through 5 corresponds to the following: 1=No (Never), 2=Infrequently, 3=Sometimes, 

4=Frequently, 5=Yes (Always). N/A indicates not applicable.
Effective Date:

January 25, 2013

Revision No.

Draft – 0

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NOTICE: This report has been reviewed for Privacy Act information and has been cleared for distribution.

However, this report is pre-decisional and has not been reviewed by the Advisory Board on Radiation and Worker 

Health for factual accuracy or applicability within the requirements of 42 CFR 82.

4.0 CONCLUSION

ORAUT-OTIB-0055 presents a discussion on the need to modify the neutron quality factors

presented in NCRP Report 38 to ICRP Publication 60 radiation weighting factors. The TIB 

presented a corrected neutron dose equivalent methodology that is recommended for use in dose 

reconstruction for measured dose, missed dose, and dose determined based on neutron-to-photon 

ratios. This TIB also recommended the use of claimant-favorable values when there is 

insufficient detailed information on neutron energies, mainly for neutron doses measured prior to 

1957 and the publication of NCRP Report 20 (NCRP 1957).

SC&A’s review of ORAUT-OTIB-0055 resulted in four findings. The first finding identified 

inconsistencies in the historical dosimetry guideline for thermal neutrons. The RBE for thermal 

neutrons is presented as a value of 5, instead of 3, as is in the Tripartite Conference at Chalk 

River minutes. A discussion supporting the recommended RBE of 5 for thermal neutrons is not 

provided in NCRP Report 17. Secondly, no rationale is provided for the use of NCRP Report 38 

as the basis for adjusting pre-1973 neutron measurements. SC&A found that ICRP Publication 

60, which forms the neutron radiation weighting factors basis for ORAUT-OTIB-0555, is 

outdated by more recent recommendations presented in ICRP Publications 92 (2003) and 103 

(2007). Lastly, SC&A found the recommendation given in ORAUT-OTIB-0055 for selecting 

the appropriate neutron energy when detailed information on the neutron energies involved in a 

worker’s exposures is not available differs from the recommendation given in OCAS-IG-001 for 

the same scenario.
Effective Date:

January 25, 2013

Revision No.

Draft – 0

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Page No.

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NOTICE: This report has been reviewed for Privacy Act information and has been cleared for distribution.

However, this report is pre-decisional and has not been reviewed by the Advisory Board on Radiation and Worker 

Health for factual accuracy or applicability within the requirements of 42 CFR 82.

REFERENCES

10 CFR §20.1004. 2011. Code of Federal Regulations, Title 10: Energy, Chapter I: Nuclear 

Regulatory Commission, Part 20: Standards for Protection Against Radiation, Subpart A: 

General Provisions, Section 20.1004 Units of radiation dose, January 01, 2011.

42 CFR 82. Methods for Radiation Dose Reconstruction Under the Energy Employees

Occupational Illness Compensation Program Act of 2000; Final Rule, Federal

Register/Vol. 67, No. 85/Thursday, May 2, 2002.

ICRP 1991. 1990 Recommendations of the International Commission on Radiological 

Protection. ICRP Publication 60. Ann. ICRP 21 (1-3). International Commission on 

Radiological Protection.

ICRP 2003. Relative Biological Effectiveness, Radiation Weighting and Quality Factor. ICRP 

Publication 92. Ann. ICRP 33 (4). International Commission on Radiological Protection.

ICRP 2007. The 2007 Recommendations of the International Commission on Radiological 

Protection. ICRP Publication 103. Ann. ICRP 37 (2-4). International Commission on 

Radiological Protection.

ICRP 2010. Conversion Coefficients for Radiological Protection Quantities for External 

Radiation Exposures. ICRP Publication 116, Ann. ICRP 40(2–5). International Commission on 

Radiological Protection.

NCRP (National Council on Radiation Protection and Measurements) 1954. Permissible Dose 

from External Radiation Sources of Ionizing Radiation, Report 17 (NBS Handbook 59), National 

Bureau of Standards, U.S. Department of Commerce, Washington, DC.

NCRP (National Council on Radiation Protection and Measurements) 1957. Protection Against 

Neutron Radiation up to 30 Million Electron Volts, Report 20 (NBS Handbook 63), National 

Bureau of Standards, U.S. Department of Commerce, Washington, DC.

NCRP (National Council on Radiation Protection and Measurements) 1973. Protection Against 

Neutron Radiation, Report 38, NCRP Publications, Washington, DC.

OCAS 2007. External Dose Reconstruction Guideline, OCAS-IG-001, Rev. 3, National Institute 

for Occupational Safety and Health, Office of Compensation and Analysis, Cincinnati, Ohio.

ORAUT 2006. Technical Basis for Conversion from NCRP Report 38 Neutron Quality Factors 

to ICRP Publication 60 Radiation Weighting Factors for Respective IREP Input Neutron Energy 

Ranges, ORAUT-OTIB-0055, Rev. 00. Oak Ridge Associated Universities Team, Cincinnati, 

Ohio. June 5, 2006. 
Effective Date:

January 25, 2013

Revision No.

Draft – 0

Document No.

SCA-TR-PR2013-0055

Page No.

19 of 19

NOTICE: This report has been reviewed for Privacy Act information and has been cleared for distribution.

However, this report is pre-decisional and has not been reviewed by the Advisory Board on Radiation and Worker 

Health for factual accuracy or applicability within the requirements of 42 CFR 82.

Taylor, L.S., 1984. The Tripartite Conferences on Radiation Protection. Canada, United 

Kingdom, United States (1949–1953). U.S. DOE Report HVO-270 (DE 84016028), U.S. 

Department of Energy, Office of Scientific and Technical Information, Washington, DC.

Thomas, R.H., 2003. “Accelerator Radiological Protection, A Personal and Privileged 

Odyssey,” William Morgan Lecture, Health Physics Society Annual Meeting, San Diego, 

California. July 23, 2003.

Wiley, S.W., 2003. “Information Requested by the National Institute for Occupational Safety 

and Health (NIOSH) under the Energy Employees Occupational Illness Compensation Program 

Act (EEOICPA),” BWXT Y-12 L.L.C., letter to G.D. Kerr, Kerr Consulting. July 30, 2003.