TO: Advisory Board on Radiation and Worker Health Work Group on TBD-6000 

FROM: Robert Anigstein and John Mauro, SC&A 

SUBJECT: Review of NIOSH Report: Addendum to Dose Estimates for Betatron Operations 

DATE: March 25, 2012 

Review of “Addendum to Dose Estimates for Betatron Operations White Paper” 

During its meeting on March 15, 2012, the ABRWH Work Group on TBD-6000 assigned several 

action items to SC&A, including responding to the expected revision of the NIOSH white paper 

on betatron operations at GSI, originally issued on January 13, 2012. The following is a review 

of “Battelle-TBD-6000 Appendix BB General Steel Industries: Addendum to Dose Estimates 

for Betatron Operations” (Allen 2012b), which we received on March 23. 

Allen (2012b) reported that he recalculated the dose rates outside the shooting room of the New 

Betatron Building, removing the lead-shielded door between the betatron building and the 

adjacent No. 10 Building from his MCNPX model. This change was made because the earliest 

reference to the lead shielding was in a communication to AEC in January 1968, which was 

18 months after the period of covered operations at GSI. Some GSI workers have disputed the 

presence of the lead shielding during the covered period. Because there is uncertainty about 

when the lead shield was installed, Allen used the claimant-favorable assumption that the lead 

was not present during the covered period. We agree with this revision. 

However, Allen (2012b) retained in his analysis several features that we previously disputed, as 

discussed by Anigstein and Olsher (2012). First, we disagree with his arbitrarily selected set of 

15 betatron shooting scenarios, 10 of which do not represent realistic practices employed in 

betatron radiography. During the March 15 work group meeting, Mr. Allen explained that the 

shots aimed at an angle of 45o to the surface of the casting were meant to encompass other 

geometries than the radiographic examinations of a hollow cylindrical axle first used by SC&A 

(2008) as an example of a large casting actually produced and tested at GSI. We do not agree 

that shooting at a 45o angle to the surface represents a realistic procedure for this or any other 

casting. 

Next, we disagree with Allen’s (2012b) methodology of apportioning the shots among these 15 

scenarios on the basis of the MCNPX analyses of exposure rates at the location of the film-badge 

storage rack. Allen revised the location, based on information furnished by a former 

GSI betatron operator. Anigstein and Olsher (2012) presented a diagram showing the location of 

the rack in the New Betatron Building, but not in the control room. The purpose of that diagram 

was to illustrate that Allen (2012a) was mistaken in assuming that the badges were stored in the 

control room and that both the worker badges and the control badge were exposed to stray 

radiation even when they were not being worn. Having interviewed Mr. to obtain that 

information, we were aware that the badge rack had also been in a second location in the New 

Betatron Building, but we showed only one location for purposes of illustration. 

Allen (2012b) used the location illustrated by Anigstein and Olsher (2012) to adjust the 

frequency of his various shooting scenarios so that the weekly exposure at the film-badge storage 

Review of Addendum to Dose Estimates 1 SC&A –March 25, 2012
 

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.
 
 

 

rack would be equal to 10 mR. We disagree with this procedure for several reasons. First, as 

stated above, the shooting scenarios were arbitrary and, in most cases, unrealistic. Because his 

report was issued on March 23, two days prior to the present review, we did not have the 

opportunity to obtain Allen’s new MCNPX input files, so we are at a disadvantage in assessing 

the accuracy of the exposure assessment. However, Anigstein and Olsher (2012) observed that 

Allen’s earlier files utilized a density of 0.92 g/cm3

 for the wall between the control room and the 

rail tunnel—Allen (2012b) did not indicate that this parameter was changed in his revised 

analysis. SC&A (2008), in the absence of information about the construction of the wall, had 

adopted that density in the interest of a claimant-favorable assessment of worker exposures in the 

control room. Since the drawings accompanying the GSI AEC application indicate that the wall 

was made of mortar-filled concrete blocks, that assumption is no longer tenable nor, in Allen’s 

analysis, is it claimant favorable: reducing the shielding of the film badges tends to understate 

the worker exposure in the No. 10 Building. 

Furthermore, we question any analyst’s ability, based on currently available data, to assess the 

exposure at the rack location, absent any information on the intervening interior walls, furniture 

or equipment that could shield the film badges from stray radiation, the presence of a second 

story that would reduce skyshine, etc. Most exposure assessments use simplifying, claimantfavorable assumptions that tend to maximize the exposures; however, in Allen’s approach, 

maximizing the exposures to the film-badge storage rack minimizes the estimated exposure of 

the workers. 

Allen (2012b) performed an “example calculation,” in which he assumed that the betatron 

operator received an exposure of 5 mR per week from residual radiation from the betatron after 

shutdown. Because the weekly exposure at the film badge rack is thus reduced to 5 mR, Allen 

recalculated the frequency of the various shot scenarios. This had the effect of increasing the 

betatron operator’s annual exposure to photon radiation while reducing his neutron dose. Both 

the exposure and the neutron dose to the layout man were reduced on the basis of this 

calculation. This calculation was performed to explore the possible effect of the residual 

betatron operation. Since, as shall be shown, the results do not change the maximum doses from 

the bounding scenario, we did not examine these calculations any further. 

Table 1 lists the annual doses to the betatron operators calculated by Anigstein and Olsher 

(2012), as well as the maximum exposures and doses presented by Allen (2012b). We list the 

photon doses based on the assumed 5-mR/week exposure to residual betatron radiation; since 

this assumption reduces the neutron doses, as calculated by Allen, we list the neutron doses 

calculated in the absence of this assumption. We list the beta doses to the skin presented by 

Allen (2012a) for ease of reference—these doses have not been revised. 

Table 2 lists the corresponding doses to layout men. Since the assumed residual betatron 

radiation reduces both Allen’s photon and neutron exposure estimates, we list the doses 

calculated in the absence of such an assumption. We disagree with Allen’s assignment of these 

doses for 1953–1966 (with a 50% reduction in 1966 to account for the end of covered operations 

on June 30). This scenario places the layout man near the entrance to the New Betatron 

Building. Since this building was constructed in 1963, assigning these doses for prior years does 

not constitute a plausible scenario. We believe that the bounding exposure scenario for earlier 

Review of Addendum to Dose Estimates 2 SC&A –March 25, 2012
 

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.
 
 

 

 

c 

years should be represented by a radiographer employing 226Ra using the fishpole technique, as 

discussed by Anigstein (2011). As in Table 1, we list the beta doses to the skin presented by 

Allen (2012a)—these doses have not been revised. 

Table 1. Annual Doses to Betatron Operators 

Exposure Neutron dose Beta dose to skin (rads) 

Year (R) (rem) Hands and forearms Other skin 

SC&Aa DCAS SC&A DCAS SC&A DCASc

 SC&A DCASc 

1953-1957 1.35 0.734 0.48 0.050 33.4 25.9 6.27 2.27 

1958 1.35 0.734 0.48 0.050 32.1 25.9 6.22 2.27 

1959-1960 1.35 0.734 0.48 0.050 30.9 25.9 6.18 2.27 

1961 1.35 0.763 0.48 0.056 34.2 29.5 6.30 2.47 

1962 1.35 0.702 0.48 0.043 27.2 21.8 6.04 2.04 

1963 1.35 0.586 0.47 0.019 13.9 7.0 5.56 1.23 

1964 1.35 0.558 0.46 0.013 10.7 3.5 5.45 1.03 

1965 1.35 0.554 0.46 0.012 10.2 3.0 5.43 1.00 

1966b 0.68 0.275 0.23 0.006 4.8 2.4d

 2.71 0.97d 

Note: SC&A values from Anigstein and Olsher (2012) 

a Maximum exposure, assuming hypothetical 30-keV residual radiation from betatron behind operator’s back 

b During contract period: January 1–June 30 

Not revised from Allen (2012a)—included for reference 

d As listed by Allen (2012a)—should be prorated for 6-months of exposure in 1966 

Table 2. Annual Doses to Layout Men 

Exposure Neutron dose Beta dose to skin (rads) 

(R) (rem) Hands and forearms Other skin 

SC&A DCAS SC&A DCAS SC&A DCAS SC&A DCAS 

9.20 4.483 0.46 0.148 4.20 1.02 2.45 0.54 

Note: SC&A values from Anigstein and Olsher (2012). See text for applicable periods. 

As shown in Tables 1 and 2, the layout man constitutes the limiting scenario for photon 

exposures in both the SC&A and DCAS analyses. However, the exposure calculated by DCAS 

is less than one-half of that estimated by SC&A (Anigstein and Olsher 2012). Although the 

SC&A scenario is based on a single bounding exposure geometry, it is a realistic scenario, based 

on a photograph and information from a former betatron operator. Furthermore, whereas Allen 

(2012b) located the layout man at the center of the railroad track, an implausible location, we 

placed him at equal distances on either side of the track and found that one position had almost 

twice the exposure rate of the other, indicating that the center would not necessarily lead to the 

maximum exposure. The DCAS neutron calculations yield far lower doses than do the SC&A 

estimates—10-fold lower in the case of the betatron operator, and less than one-third for the 

layout man. 

Review of Addendum to Dose Estimates 3 SC&A –March 25, 2012
 

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.
 
 

 

In summary, we conclude that the analyses presented by Allen (2012a and 2012b) represent a 

major advance over the betatron studies described by Allen and Glover (2007). However, we 

believe that further revisions are required in order for the results to be scientifically correct and 

claimant favorable. 

References 

Allen, D., (NIOSH/DCAS). 2012a. “Battelle-TBD-6000 Appendix BB General Steel Industries: 

Dose Estimates for Betatron Operations.” 

Allen, D., (NIOSH/DCAS). 2012b. “Battelle-TBD-6000 Appendix BB General Steel Industries: 

Addendum to Dose Estimates for Betatron Operations.” 

Allen, D., and S. Glover. 2007. “Site Profiles for Atomic Weapons Employers That Worked 

Uranium and Thorium Metals - Appendix BB: General Steel Industries,” Battelle-TBD6000,Appendix BB, Rev. 0. http://www.cdc.gov/niosh/ocas/pdfs/tbd/b-6000-apbb-r0.pdf 

Anigstein. 2011. “Update on the Use of Sealed Radioactive Sources At General Steel Industries.” 

Anigstein, R., and R. H. Olsher. 2012. “Response to ‘Battelle-TBD-6000 Appendix BB General 

Steel Industries: Dose Estimates for Betatron Operations.’” 

S. Cohen & Associates (SC&A). 2008. “Review of ‘Site Profiles for Atomic Weapons 

Employers That Worked Uranium and Thorium Metals - Appendix BB: General Steel 

Industries,’ Battelle-TBD-6000, Appendix BB, Rev. 0.” 

http://www.cdc.gov/niosh/ocas/pdfs/abrwh/scarpts/scagsireview.pdf 

Review of Addendum to Dose Estimates 4 SC&A –March 25, 2012
 

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.