Division of Compensation Analysis and Support

Technical Information Bulletin

Document Number: 

 DCAS-TIB-0010 

Effective Date: 11/28/2011

Revision No. 04

Best Estimate External Dose Reconstruction for Glovebox Workers Page 1 of 16 

Approval: Signature on file Date: 11/28/2011 

 J.W. Neton, Associate Director for Science

Supersedes:

 Rev. 03

RECORD OF ISSUE/REVISIONS

ISSUE 

AUTHORIZATION 

DATE

EFFECTIVE

DATE

REV. NO.

DESCRIPTION

5/18/2005 5/18/2005 1 Updated document to provide methodology 

and guidance on applying correction factors 

to glovebox workers for over and under 

estimation of dose.

12/30/2005 12/30/2005 02 Modified to provide best estimate approach.

06/18/2010 6/18/2010 03 Revised to expand the purpose section; 

clarified the use of ATTILA for geometric 

analysis only; standardized tables and 

graphs; and discussed organs affected by 

the process. Document number changed to 

reflect official name change from OCAS to 

DCAS. Incorporated SC&A review 

comments.

11/02/2011 11/28/2011 04 Deleted MCNP analyses from appendices

and minor grammatical and formatting 

changes.
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1.0 Purpose

The purpose of this technical information bulletin (TIB) is to provide guidance on dose 

reconstructions for glovebox workers. This TIB discusses the special exposure characteristics 

that may be encountered by energy employees who work with gloveboxes and provides special 

dose correction factors or modifiers that should be applied to affected energy employees’ dose. It 

should be noted that throughout this technical information bulletin, the term glovebox is used, 

however, in the early years of the Atomic Energy Commission (AEC) facilities; these types of 

units were commonly called dry boxes as their original intent was to isolate radioactive materials. 

Throughout this report these terms should be considered equivalent.

A general approach for computation of a torso correction factor will be considered for a single 

glovebox using a radiation transport modeling software called ATTILA. Geometry is the variable

of concern. 

2.0 Special Exposure Considerations 

Geometry deserves special consideration when conducting dose reconstructions for glovebox 

workers. Therefore the dose reconstructions affected by this TIB are those for cancers of the 

stomach, liver, bladder, prostate, ovaries, testes, genitalia, or other cancers that appear in the 

region of those organs. The degree of underestimation is dependent on the distance between the 

radiological source (exposure geometry), the materials used to construct the glovebox 

(attenuation or shielding), and the relative duration (time) that an energy employee conducted 

work in the glovebox. In general, very little is known about the duration of the exposure which is 

typically dependent upon the specific duties of the energy employee.

2.1 Exposure Geometry

Exposure geometry is a special consideration in dose reconstruction of energy employees who 

primarily worked in gloveboxes. An underestimation of the dose could occur if the energy 

employee wore his/her dosimeter on the lapel and not the center area of the chest or on the waist. 

This underestimation could result due to the difference in relative distance between the external 

radiation source, the organ of interest, and the dosimeter. Only organs in the lower torso are 

affected, since design of the glovebox places these organs closer to the radiological source than 

the dosimeter. The dose to lung is considered to have been reasonably approximated by the 

dosimeter at least to within the dosimeter uncertainty and the dose to the face and head would 

have been slightly lower than the dose measured by the dosimeter worn on the lapel. 

2.2 Glovebox design

Low energy photons have a relatively low penetrating power and are easily attenuated. As a 

result, the design of the glovebox is an important consideration in accurately estimating the low 

energy photon dose. A review of the literature indicates that the design of gloveboxes varied 

widely.

1, 2 In some instances almost fully metal gloveboxes were used with only a small area for 

viewing (Figure 1), other gloveboxes had relatively large viewing areas (Figure 2-4), and others 

had a combination of multiple viewing areas with, in some designs, an opening that coincides 

with the center of the lower torso (Figure 5). 
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Figure 1 Plutonium gloveboxes at LANL (1) 

Figure 2 Plutonium gloveboxes at Chalk River (1)
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Figure 3 Plutonium gloveboxes at Hanford (2)

Figure 4 Plutonium gloveboxes at LANL’s CMR facility (1)
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Figure 5 Other plutonium gloveboxes at Hanford. Note the viewing area in direct line with the 

lower torso in the center between the gloves.

 (2)

Since the actual glovebox design is not known for each dose reconstruction scenario, a claimant 

favorable approach is used by assuming the glovebox had a large viewing face and the worker’s 

lower torso was exposed more by elevation of the simulated worker as shown in the ATTILA 

figures. This is considered a reasonable but necessary claimant favorable assumption, since 

identifying the actual glovebox design at each facility (DOE site, building, room, etc.) would be 

prohibitively time consuming. In addition, during the course of an energy employee’s 

employment, it is likely that they conducted work in many different types of gloveboxes, thus a 

time dependent work location correction factor for each glovebox design would be necessary to 

account for such differences. The effect of this assumption is an overestimate of the dose to the 

lower organs rather than an underestimate. 

While the face (viewing area) of a glovebox was typically constructed using a clear polymer type 

material such as Lucite3

, the sides and bases of gloveboxes are almost always constructed of 

sturdy materials such as wood, aluminum, and most commonly steel. These materials generally 

shield an individual worker from side exposure to low energy photons. As a result the low energy 

photon dose is virtually 100% from the anterior- posterior exposure geometry due to the 

radiological materials in the specific glovebox where the energy employee conducted his/her 

work. On the other hand, the intermediate and high energy photon dose would be a combination 

of the direct work in the glovebox as well as surrounding gloveboxes and process lines. 
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3.0 Methodology

 Figure 6 Diagram of Human Torso (4)

In the scenario used to develop a correction factor the radiation source was assumed to be directly 

in line with the specific organ of interest in the lower portion of the torso. To accurately estimate 

the underestimate of dose, the actual height of the glovebox and location of the source in relation 

to the energy employee’s organ of interest and the distance to their lapel would be necessary

(Figure 6). This analysis used 24 inches as a reasonable claimant favorable assumption to 

simplify the calculation. In general, the correction factors for smaller stature workers would be 

less than those indicated in this technical information bulletin as the 24 inches is based on a 

moderately tall worker. In some instances, especially in the case of small stature workers, some 

of the organs could be below the bottom of the glovebox, thus low energy photons are virtually 

completely shielded (attenuated) and intermediate energy photons more attenuated than those 

measured on the dosimeter (note the relative difference in worker stature in Figure 3). 

As stated above, an average distance of 24 inches (61 cm) was assumed to be the distance 

between the lower torso and the lapel. The distance between the radiation source and the lower 

torso was assumed to vary from 6 inches to 18 inches. These distances were selected as the 

general range from which a worker could conduct most of their work in the glovebox. A source 

closer than 6 inches, while technically possible in some glovebox designs, is not very likely given 

the body location with respect to the glovebox. In some instances (Figure 2) a nearly straight 

down movement would be needed to position a source 6 inches from the lower torso. Eighteen

inches was selected as a reasonable upper distance. While some workers with longer arms might 

have been able to reach the back of the glovebox, a comfortable working distance for most 

workers would be between 10-14 inches between the source and the lower torso with a central 

tendency estimated at approximately 12 inches. This is used as the source distance.

≈ 24 inches (61 cm)

≈ 12 inches (30 cm)
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At source distances greater than 48 inches, the relative difference between the dose to the lower 

torso and the lapel is less than 25% which is typically within the uncertainty of the dosimeter 

measurement. Thus the intermediate and high energy photon dose to the lower torso is 

approximately equal to the dose measured by the dosimeter on the lapel. 

A model to determine the best-estimate correction factor for lower torso exposure to a glovebox 

worker was developed using modeling software called ATTILA. It is a multi-group deterministic 

radiation transport environment that can directly use Computer Aided Design (CAD) data and 

model complex geometry efficiently and accurately to solve large 3-D problems. ATTILA can 

solve neutron and photon transport equations and accounts for the same transport effects as 

Monte Carlo modeling (as used by e.g. MCNP), but is faster. Both ATTILA and MCNP are 

widely accepted radiation transport codes. ATTILA was developed by the Transport Methods 

Group at LANL and made commercially available by Radion Technologies (now Transpire, Inc.). 

The code is maintained under an ISO 9001:2000 certification (http://www.transpireinc.com). It is 

a deterministic code that solves the Boltzmann transport equation analytically. MCNP uses a 

Monte Carlo approach which tracks large numbers of individual particles. Both approaches are 

valid. With ATTILA, a mesh is generated consisting of discrete points in space in the entire 

domain of the model. The transport equation is then solved for flux as a function of angle, energy 

and particle type, at every mesh point. Interpolation between mesh points is also performed. 

The ATTILA model’s geometry and flux contours can be seen in Figure 7. The makeup of the 

glovebox is a stainless steel top, bottom and sides with a Lucite front face. This was deemed a 

more conservative, i.e. claimant favorable, design compared to boxes with partial stainless steel 

front faces. The human figure also provides for more of the lower torso to be exposed above the 

table top, again to be conservative. 

Figure 7 ATTILA model geometry and flux contours. 
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3.1 Data analysis

ATTILA calculates photon flux at all mesh points in the domain of the problem. In order to 

avoid selection bias from a single-point calculation, data was extracted at 30 points each in the 

regions A and B on a plane perpendicular to the x-axis corresponding to the surface of the body 

(Figure 8). The regions A and B correspond to upper torso and lower torso respectively. Flux 

distributions for each region were then determined by CRYSTAL BALL software. The flux data 

from regions A and B follow a lognormal distribution. 

Figure 8 Data point selection regions. Various colors signify

relative magnitude of flux across a selected plane on the x-axis.

Ratios between flux distributions in regions B and A formed another set of data for analysis by 

CRYSTAL BALL software. 
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Figure 9 Distribution of lower torso to upper torso ratios

3.2 Results

An effort has been made to include the uncertainty of the dosimeter in the glovebox correction 

factor. There are two situations concerning such uncertainty, one where the combination of 

dosimeter reading and organ dose conversion factor (DCF) is a constant and the other where that 

value is a normal distribution with+/-30% standard deviation. 

3.2.1 Geometric mean and standard deviation when dosimeter uncertainty

constant 

The resulting distribution of ratios from ATTILA was determined to be lognormal (Figure 9) with 

a geometric mean of 2.19 and a geometric standard deviation of 1.34. This mean and standard 

deviation will be applied to the dosimeter reading for deep dose when dosimeter correction factor

is considered constant, i.e. equal to 1.3. 

3.2.2 Geometric Mean and standard deviation when dosimeter uncertainty is a 

distribution

The resultant geometric mean and standard deviation for the distribution produced (Figure 10) by 

CRYSTAL BALL when the lower-to-upper-torso distribution in Figure 9 is combined to a 

truncated normal dosimeter uncertainty distribution (only positive values are considered) is 2.3 

and 1.13 respectively. This produces a glovebox correction factor that includes a dosimeter 

distribution uncertainty and is used when the dosimeter uncertainty of +/-30% needs to be 

considered. 

Frequency Chart

.000

.005

.011

.016

.022

0

109.2

218.5

327.7

437

0.89 1.69 2.49 3.29 4.08

20,000 Trials 19,677 Displayed

Forecast: Lower to Upper
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Forecast: Corrected Dose

Lognormal Distribution 10,000 Trials

0

50

100

150

200

250

300

350

400

0.04 1.58 3.12 4.66 6.20

Frequency

Figure 10 Combined distribution of lower-to-upper-torso ratio and dosimeter uncertainty

3.3 Reasonable Claimant Favorable Assumptions 

Listed below are several claimant favorable assumptions used in the development of this 

methodology that could result in an overestimate of the actual dose. 

 

• Claimant favorable glovebox design

• Direct line of sight to lower torso with Lucite as shielding 

• Distance from lower torso to lapel based on tall workers

Obtaining data for precise evaluation of these parameters would require extensive time and 

research for each nuclear facility and in some instances the information cannot be obtained (e.g. 

facility has undergone D&D or other significant modification over time). 

4.0 Applicability to Neutron Doses

The high energy photon correction factors described above may also be appropriate for 

application to measured neutron dose and potentially to some applications using neutron to 

photon (n-p) ratios. An evaluation of the applicability to neutron dose requires a work site 

specific evaluation. 

When a neutron to photon ratio method is used to estimate the neutron dose, it is important to 

know the general locations of the photon and the neutron dosimeters. In the case of the Savannah 
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River facility, the neutron to photon (n-p) ratios were developed from joint measurement data of 

the thermoluminescent dosimeter (TLD) typically worn on the lapel and the neutron dosimeter 

(belly button dosimeter) worn around the waist. In this instance, the correction factor should not 

be applied since the measured neutron dose is a good representation of the dose to the lower 

torso. In later years, however, when the dosimeter combined photon and neutron TLD elements, 

a correction factor would need to be applied. 

However at other facilities, if the NTA film dosimeter was worn on the lapel and a ratio was 

determined based on a photon dosimeter also worn on the lapel, then the correction factor should 

be applied. The most efficient method for doing so would be to apply the correction factor to the 

photon dose before applying the neutron to photon ratio. 

5.0 Summary

This Technical Information Bulletin provides guidance for dose reconstruction to organs located 

in the lower torso. The correction factors for best-estimate of dose provided in Table 1 

respectively are for photons emanating from gloveboxes and measured using a dosimeter worn on 

the lapel. The factors should be applied for all photon energies and doses recorded either as the 

shielded element of the dosimeter or as the deep dose. The choice of factor will depend on 

whether the 30% dosimeter uncertainty is to be folded in or not. 

Table 1: Lower torso best-estimate dose and/or exposure rate correction factors for glovebox 

work. 

Dosimeter Uncertainty 

Constant Distribution Geometric Mean Geometric Standard Deviation 

Yes Lognormal 2.19 1.34 

No Lognormal 2.3 1.13 
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6.0 References

 

1. A. S. Coffinberry and W. N. Miner, The Metal Plutonium, The University of Chicago 

Press, Chicago, Illinois, 1961. 

2. Office of Environmental Management, (1997) U.S. Department of Energy. Linking 

Legacies: Connecting the Cold War Nuclear Weapons Production Processes to Their 

Environmental Consequences, DOE/EM-0319, U.S. Department of Energy, Washington 

D.C.

3. Watson, E. C. (1959) A Film Technique for Measuring the Exposure Dose from 

Plutonium, Health Physics, Vol. 2 pp. 207. 

4. Merck (2004), The Merck Manual – Second Home edition, illustration obtained at the 

following website. http://www.merck.com/mrkshared/mmanual_home2/fg/fg001_1.jsp 

5 Grove Engineering (2002), Microshield Program version 5 User Manual, Rockville 

Maryland. 

6. Decisioneering Inc. (2000), Crystal Ball 2000 User Manual, Denver Colorado. 

7. 42 C.F.R pt 82, Methods for Radiation Dose Reconstruction Under the Energy Employee 

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

Register/Vol.67, No. 85/Thursday, May 2, 2002, p 22314. 

8. NIOSH, (2002) External Dose Reconstruction Implementation Guideline, Rev 1, OCASIG-001, National Institute for Occupational Safety and Health, Office of Compensation 

Analysis and Support, Cincinnati, Ohio. 

9. McGhee and Wareing. (2004) AttilaTM Version 4: User's Manual, Radion Technologies 

Los Alamos, NM. 
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Appendix A 

ATTILA Model Data

Figure A1 Dimensions (all lengths are in centimeters)

Figure A2 Dimensions (all lengths are in centimeters)

Pu point 

source at 

coordinates 

(0,0,34 cm) 

below center

point in box
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Thirty flux points, at surface of body, randomly chosen from box A and B in Figure A3 below. 

Figure A3 Analysis Points

Table A1 Photon source 1g Pu and 1ppb 236Pu, decayed 

Group Upper Energy (MeV) No 236Pu (gamma/s) 234Pu (gamma/s) Total (gamma/s)

1 5.00E-03 1.76E+06 3.82E+01 1.762E+06

2 1.00E-02 2.77E+06 1.12E+02 2.770E+06

3 1.50E-02 2.40E+08 4.34E+02 2.396E+08

4 2.00E-02 9.26E+03 3.78E+01 9.301E+03

5 2.50E-02 5.49E+02 2.49E+01 5.742E+02

6 3.00E-02 5.94E+06 2.18E+01 5.943E+06

7 3.50E-02 3.63E+05 1.77E+01 3.625E+05

8 4.00E-02 1.30E+05 1.45E+01 1.299E+05

9 4.50E-02 3.10E+05 1.23E+01 3.098E+05

10 5.00E-02 2.27E+05 1.43E+01 2.272E+05

11 5.90E-02 5.00E+05 7.07E+00 5.003E+05

12 6.00E-02 9.28E+07 7.07E+00 9.282E+07

13 7.00E-02 5.48E+04 1.23E+01 5.477E+04
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Group Upper Energy (MeV) No 236Pu (gamma/s) 234Pu (gamma/s) Total (gamma/s)

14 8.00E-02 4.34E+04 2.23E+02 4.361E+04

15 9.00E-02 4.62E+02 7.84E+01 5.404E+02

16 1.00E-01 1.25E+05 8.78E+00 1.254E+05

17 1.25E-01 1.99E+05 1.81E+01 1.989E+05

18 1.50E-01 1.42E+05 8.36E+00 1.422E+05

19 1.75E-01 1.49E+04 5.89E+00 1.487E+04

20 2.00E-01 5.83E+03 8.10E+00 5.841E+03

21 2.50E-01 5.33E+04 3.57E+02 5.361E+04

22 3.00E-01 5.24E+03 4.06E+01 5.284E+03

23 3.50E-01 3.76E+04 1.60E+01 3.763E+04

24 4.00E-01 7.01E+04 2.87E+00 7.007E+04

25 4.50E-01 3.77E+04 2.24E+00 3.767E+04

26 5.00E-01 2.21E+03 3.69E+00 2.218E+03

27 6.00E-01 3.00E+02 2.74E+02 5.741E+02

28 7.00E-01 2.82E+03 1.26E+00 2.820E+03

29 8.00E-01 1.34E+03 9.77E+01 1.438E+03

30 9.00E-01 4.37E+01 3.50E+01 7.864E+01

31 1.00E+00 1.37E+01 3.18E+00 1.691E+01

32 1.25E+00 3.98E+01 7.71E+00 4.748E+01

33 1.50E+00 2.94E+01 2.15E-01 2.964E+01

34 1.75E+00 1.68E+01 2.32E+01 3.997E+01

35 2.00E+00 1.45E+01 1.39E+00 1.592E+01

36 2.60E+00 1.74E+01 2.25E-04 1.743E+01

37 2.70E+00 7.07E-07 2.41E+02 2.410E+01

38 3.00E+00 9.85E+00 1.23E-06 9.852E+00

39 3.50E+00 5.86E+00 6.52E-07 5.860E+00

40 4.00E+00 3.37E+00 3.34E-07 3.367E+00

41 5.00E+00 3.01E+00 2.55E-07 3.007E+00

42 6.00E+00 1.00E+00 6.80E-08 1.001E+00

43 8.00E+00 4.30E-01 2.25E-08 4.301E-01

44 1.10E+01 4.89E-02 1.76E-09 4.891E-02

Total 3.45E+08 2.21E+03 3.452E+08

Use total gammas per second column and the associated energies for 1 gram Pu metal.
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Glove box materials 

Figure A4 Glove box materials

Steel – box 

sides, bottom 

and table 

Steel –

box top

Lexan –face 

plate and 

glove ring 

supports 

Man -

water

Air filled 

room