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 Response Paper No. 1 

DATE: Monday, January 26, 2015 

Review of “Responses to Sanford Cohen & Associates Review of Battelle-TBD-6000 

Appendix BB (General Steel Industries, Rev. 1),” Response Paper 

On January 8, 2015, David Allen (NIOSH/DCAS) issued two “Response Papers,” responding to 

our review of a revision of Appendix BB to TBD-6000 (Anigstein and Mauro 2014b). The 

present memo is our reply to the first of these Response Papers (Allen 2015a). We will comment 

only on those finding that require further discussion. 

Finding 1: Neutron Dose Rates 

In referring to the fact that Appendix BB, Rev. 1 (Allen 2014), lists effective doses from 

neutrons, Allen (2015a) stated: 

The values in Appendix BB match the numbers agreed to during an exchange of 

files between SC&A and NIOSH prior to the drafting of the appendix revision. 

Both SC&A and DCAS neglected to realize at the time that calculating effective 

dose was not appropriate. 

To understand the genesis of the use of effective dose from exposures to neutrons, we need to 

understand what transpired between SC&A and NIOSH during and prior to the January 16, 2014, 

meeting of the Work Group on TBD 6000, when NIOSH and SC&A, with the approval of the 

work group, agreed on the assignment of doses from penetrating external radiation. We first 

need to return to the initial SC&A (2008) review of Appendix BB, Rev. 0 (Allen and Glover 

2007). At that time, we noted that Allen and Glover did not include exposure to neutrons in their 

GSI site profile. We calculated photon exposures in roentgens since at least some of the photon 

exposures (referred to as “doses” by Allen and Glover) were listed in those units. In order to 

demonstrate the significance of neutron exposures in comparison to photons, we elected to 

express the effects of the two types of radiation in terms of effective dose, the most commonly 

used quantity for radiation protection. Our purpose was to critique the NIOSH model, not to 

prescribe a methodology for future dose reconstructions. 

To help SC&A and NIOSH explain differences in the results of the exposure assessments, the 

two organizations exchanged MCNPX input and output files used in their respective analyses. 

Allen (2012a, 2012b) presented dose rates from neutrons emitted during betatron operations at 

GSI. The results were listed in mrem, but the dosimetric quantity was not specified. However, 

an examination of the MCNPX input files used for these analyses, which David Allen 

transmitted to the senior author of this memo, show that the results are reported as effective dose. 

(In fact, the input files were based on the files previously furnished to NIOSH by SC&A, which 

contained neutron-fluence-to-effective-dose conversion coefficients listed by ICRP, 1997.) 

Review of NIOSH Response Paper No. 1 -1- SC&A – January 26, 2015 

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In late 2013, we revised our neutron dose calculations, using a more recent version of MCNPX 

and improved code parameters. To maintain continuity with previous analyses, we again 

expressed the results in terms of effective dose. As requested, we shared our MCNPX input and 

output files with NIOSH. NIOSH agreed with our method of deriving doses based on the output 

of our MCNPX analyses. It was our understanding at the time that the purpose of the 

information exchange was to agree on the models used to calculate the doses, not to prepare a 

prescription for dose calculations. 

Following the exchange of MCNPX files and subsequent calculations of ß skin doses, we 

realized that NIOSH was planning to use our MCNPX output files as the bases of their dose 

calculations for GSI. We also realized that NIOSH would need a dosimetric quantity other than 

effective dose to calculate organ doses from neutron radiation. By this time, however, we had 

started the final set of MCNPX computer runs to calculate neutron doses. We would have had to 

perform a new set of MCNPX simulations to calculate neutron ambient dose equivalents (one of 

the quantities that could be used for such assessments), which we anticipated would require 

several days of running time. There was not enough time to perform these analyses prior to the 

next work group meeting, which was scheduled for January 16, 2014. Furthermore, to quote 

from our earlier report, “During the December 19, 2013, meeting of the ABRWH Work Group 

on TBD-6000, SC&A was asked to provide an update to our previously calculated doses to GSI 

employees from external exposure to penetrating radiation (Anigstein and Mauro 2014a).” The 

calculation of neutron ambient dose equivalents was not part of that assignment. We did perform 

these analyses as part of our review of Allen (2015a) to determine the numerical differences 

between effective doses and ambient dose equivalents and to demonstrate that the two quantities 

could not be used interchangeably. (We found that each of these runs required between 96 and 

158 hours of computer time, confirming our previous expectations). 

We concur with the DCAS decision to “revise the [neutron dose] calculations to use either 

ambient dose equivalent or deep dose equivalent conversions [Allen 2015a].” DCAS may 

choose to use the MCNPX files that we used to calculate the neutron ambient dose equivalent, 

which we furnished to DCAS on September 29, 2014. The input files included in that set were 

based on the MCNPX neutron dose calculations performed during December 2013–January 

2014—the only significant differences were the substitution of ICRP (1997, Table A.42) 

neutron-fluence-to-ambient-dose-equivalent coefficients for neutron-fluence-to-effective dose 

coefficients (ICRP 1997, Table A.41). These earlier MCNPX input files were developed in close 

collaboration with John Hendricks, one of the authors of the MCNPX code, and are considered 

to be reliable. 

Finding 2: Beta Skin Dose 

Allen (2015a) is correct in stating that “DCAS and SC&A exchanged files and reconciled 

differences late in 2013 prior to the drafting of the revision to Appendix BB.” However, it 

appears that DCAS did not blindly accept the annual ß doses to the skin of the betatron operator 

that were listed in our memo of December 5, 2013 (Anigstein and Mauro 2013, Table 5), since 

all the ß doses to the skin on the whole body and on the hands and forearms listed by Allen 

(2014, Table 5) were higher than those in our memo. Whatever changes Allen made to our doses 

Review of NIOSH Response Paper No. 1 -2- SC&A – January 26, 2015 

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do not appear to have included the dose rates at 1 m from irradiated steel. We had presented the 

dose rates at 1 m from irradiated steel as millirads per shift (Anigstein and Mauro 2013, Table 2), 

but neglected to include them in the annual summaries in our Table 5, which we obtained by 

multiplying the doses per shift by the number of shifts per year devoted to the radiography of 

steel. 

The intent of our finding was to recommend that DCAS and SC&A reconcile the differences in 

their assessments of annual ß doses to the skin of betatron operators, since agreement had been 

previously reached on assumptions and methodology. However, Allen (2015a) stated that 

DCAS intends to correct this in the next revision to Appendix BB. However, the 

original calculations assumed the steel was irradiated for 30 continuous hours. 

DCAS intends to adjust the initial dose rate to account for the intermittent 

irradiation as described in a white paper that recalculates the layout man’s beta 

dose. 

We cannot come to closure on this issue until we have had the opportunity to review the planned 

DCAS assessment of ß skin doses to the betatron operator. We will examine the revised DCAS 

assumptions and methodology, as well as the results of their calculations of ß skin doses to the 

layout man, in our upcoming review of the second NIOSH Response Paper (Allen 2015b). 

Finding 3: No Dedicated Radiography Facility in No. 6 Building Prior to 1955 

DCAS decided to assign the value of 11.34 R/y to the mode of the triangular distribution used to 

characterize the external exposures of plant personnel to direct photon radiation during the 

period 1952–1955. This is approximately 0.5% higher than the value of 11.28 R/y proposed in 

our memo (Anigstein and Mauro 2014b). We would like to take this opportunity to share our 

evolving understanding of the exposure scenarios that led to this small difference in the two 

assessments. 

Our value was based on an annual exposure duration of 941 h at the 2-mR/h exclusion boundary, 

while DCAS assumed that the duration of the radiographic exposures was 975 h/y. These values 

are based on different interpretations of a statement in the initial AEC license application: “A 

maximum of 30% of each shift is used for actual exposure [NRC 2009, p. 12].” 

In an earlier report, Anigstein (2011) performed a bounding assessment of the annual exposure 

of a radiographer inside the radiographer's office—a small room inside the radiographic 

facility—during radiography using 226Ra sources. We assumed he remained there for 30% of 

each shift, or 975 h/y. This calculation, initially intended to be an example of exposures that 

should be considered as part of the GSI site profile, was later adopted by the Work Group on 

TBD 6000 with the concurrence of NIOSH and SC&A. In performing the analysis of the 

radiographer’s exposure at the 2-mR/h exclusion boundary, we observed that the AEC license 

application further stated: “This means the source is seldom exposed for a total of more than 2 

or 3 hours for each 8 hour shift.” Thus, the 30% can be interpreted to refer to the time the source 

is exposed, rather than the time the film is exposed. Since the source would have been exposed 

Review of NIOSH Response Paper No. 1 -3- SC&A – January 26, 2015
 

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

 

 

during the 15 s the radiographer needed to position and retrieve the source, it was reasonable to 

subtract that time from the total time he spent at the exclusion boundary. 

The exposure duration assumed by DCAS in deriving exposures at the 2-mR/h boundary during 

the 1952–1955 period is consistent with the previously adopted exposure duration in the 

radiographer’s office during the 1956–1962 period, as well as being slightly more claimant 

favorable. We therefore do not object to the DCAS decision to assign the value of 11.34 R/y to 

the mode of the triangular distribution for 1952–1955. 

Finding 5: Combined Exposures to 226Ra and Betatron Operations During 1952–1962 

In our recent memo (Anigstein and Mauro 2014b), we recommended that plant personnel 

employed during the Radium Era (1952–1962) be assigned neutron and ß doses that they could 

have received while working in the Old Betatron Building, performing radiography of steel and 

uranium. Previous discussions during meetings of the Work Group on TBD 6000, as well 

technical reports produced by NIOSH and SC&A, did not address combined exposures to 

photons, neutrons, and ß rays during this era. Our recommendation is meant to fill the gap in 

previous discussions—it is not “clearly a change from what had already been discussed and 

resolved [Allen 2015a].” We made this recommendation upon noting that Allen (2014, Table 8) 

listed neutron and ß doses of zero to organs other than the skin on the hands and forearms of 

“operators” during this period. Allen (2014, Table 9) assigned photon doses of 1,300 mrem/y, 

along with ß and neutron doses, to betatron operators to be used in calculating doses to the skin 

on the hands and forearms during this period. 

Allen (2015a) argued that a radiographer working with radium sources would not have had any 

spare time to work in the betatron building, asserting that the setup time for radium exposures 

would be even longer than the 15 min assumed for the betatron. 

We disagree for several reasons. The betatron was used to radiograph large, thick castings. The 

initial shots were set up by the betatron operator and a helper. Since the betatron beam was 

directional and strongly focused, it was necessary to precisely align the position and direction of 

the head of the betatron apparatus with the film that was placed behind the casting. In contrast, 

the radium sources were used for relatively thin castings. Since the radiation was isotropic, there 

was no directional orientation and the position of the source was less critical. 

Allen’s (2014) assumption that a radiographer working with radium could not also work with the 

betatron is also negated by the recollections and dosimetry records of the one GSI radiographer 

who worked during the Radium Era and provided information about the work practices during 

that time. A summary of an interview with this worker was presented in an appendix to one of 

our earlier reports (Anigstein 2011): 

I called [Worker A] again on September 27, 2011 to ask some follow-up 

questions. The following are his responses. 

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During his weekend shifts as a radiographer, he did both radium and betatron 

radiography—perhaps 50–60% of the time using the betatron, the remainder using 

radium. He worked 80–90% of the weekends, one or two shifts per weekend. 

Sometimes there was one person per shift (in the beginning), later increased to 

two or three per shift, since it made the work go faster and they got more shots. 

In the main body of the same report, Anigstein (2011) stated: 

Another approach to estimating the doses to radiographers from 226Ra sources is 

based on [Worker A’s] “Occupational External Radiation Exposure History.” . . . 

We note that he received a whole-body dose of 9.1 rem over 18 calendar quarters, 

or an average annual dose of 2.02 rem. We also note that [he] performed 

radiography only on weekends—during the week he worked in the testing 

laboratory, where he was not knowingly exposed to radiation and would therefore 

not have been wearing his film badge. We can prorate his doses to those of a fulltime radiographer. According to [Worker A], he worked one or two shifts per 

weekend, 80%–90% of the time. To derive a high-end dose, we assumed [he] 

performed radiography one shift per weekend, 80% of the time. Thus, he would 

have worked approximately 40 shifts per year. A full-time radiographer working 

406 shifts per year would thus have received an annual dose of 20.5 rem 

(2.02 rem × 406 shifts/y ÷ 40 shifts/y = 20.5 rem). A low-end estimate is based 

on the assumption that [he] worked two shifts each weekend, working such 

weekends 90% of the time. He would have thus worked 90 shifts per year, and 

the prorated dose to a full-time radiographer would be 9.1 rem/y, which is close to 

the [mode of the triangular distribution for 1956–1962]. 

Thus, this worker’s dosimetry record and work history indicate that he received a full-timeequivalent photon dose of 9.1–20.5 rem/y, which spans and indeed exceeds the agreed-upon 

triangular distribution, which has a maximum of 12 rem/y during Worker A’s period of 

employment.1 Thus it is entirely plausible that a radiographer using radium could have received 

a dose derived from the triangular distribution and could have also worked with the betatron 

during the same period. 

Finally, we note that, as quoted in the discussion of Finding 3, “A maximum of 30% of each shift 

is used for actual exposure [NRC 2009, p. 12, italics added].” Thus, the radium exposures may 

have taken less than 30% of the time on some shifts, allowing the radiographers more time to 

work on the betatron. 

We therefore believe that, for the purpose of assigning limiting neutron doses and ß skin doses, 

radiographers working with radium should be assumed to have also worked in the betatron 

building. Given the limited number of hours devoted to uranium radiography, it is plausible and 

1

 According to the AEC regulations in effect at this time, in the case of x-ray and γ radiation, 1 R = 1 rem = 1 rad (AEC 

1960). 

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claimant favorable that the same radiographer could have participated in all of the uranium 

radiography, as well as some of the betatron radiography of steel, during the Radium Era. 

Finding 6: Beta Skin Dose to Layout Man 

Allen (2015b) presented a detailed discussion of new methodology and assumptions used by 

DCAS to calculate the ß skin dose to the layout man. We will review this report in a separate 

memo devoted to this topic. 

Finding 8: Ingestion Intakes Not Consistent with OCAS-TIB-009 

Allen (2015a) agreed that the uranium ingestion intake should be derived from the annual 

average air concentration, but suggested that it be based on the highest annual average 

concentration, rather than using the calculated average concentration for each year, which varies 

with the duration of uranium handling operations in each year. We do not object to DCAS’ 

adopting such an ingestion rate, which, for most years, is intermediate between the one presented 

by Allen (2014) and one based on our recommendation (Anigstein and Mauro 2014b) and is 

claimant favorable. 

Finding 9: Ingestion Intakes During Residual Period 

Allen (2015a) agreed that the uranium ingestion intake during the first year of the residual period 

should be based on the ingestion rate during the operational period, as discussed under Finding 8 

of this memo. 

Finding 10: External Exposure of Betatron Operator (New Finding) 

Allen (2014, Table 9) lists dose estimates for the skin of the hands and forearms of the betatron 

operator during 1952–1963 as 1,300 mrem/y. This value is based on the hypothetical 30-keV 

residual photon radiation from the betatron apparatus after shutdown and was calculated in terms 

of effective dose rates, which are incompatible with the dose conversion factors listed in OCASIG-001 (OCAS 2007). 

We suggest an alternative estimate of the residual photon radiation from the betatron apparatus, 

employing assumptions and methods similar to those used to derive the estimate of 

26 mrem/week effective dose presented by Anigstein and Olsher (2012). That estimate utilized 

the ratio of absorbed dose to the female breast from 30-keV photons in the posteroanterior (PA) 

orientation to air kerma listed by ICRP (1997, Table A.5). Again using this value— 

0.0489 Gy/Gy—we derive a value of 204.5 mrem/week air kerma that corresponds to the MDA 

of the film badge dosimeter of 10 mrem (10 mrem/week ÷ 0.0489 = 204.5 mrem/week). Since 

OCAS-IG-001 does list air kerma to organ dose conversion factors, this quantity can be used for 

dose reconstructions. Since the radiation is assumed to have an energy of 30 keV, we suggest 

that NIOSH uses the maximum dose conversion factor (DCF) listed in OCAS-IG-001 for 

<30 keV photons in the PA orientation. 

Review of NIOSH Response Paper No. 1 -6- SC&A – January 26, 2015
 

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 References 

Allen, D. 2012a. “Battelle-TBD-6000 Appendix BB General Steel Industries: Dose Estimates for 

Betatron Operations.” 

Allen, D. 2012b. “Battelle-TBD-6000 Appendix BB General Steel Industries: Addendum to 

Dose Estimates for Betatron Operations White Paper.” 

http://www.cdc.gov/niosh/ocas/pdfs/dps/dc-btronadd-0312.pdf 

Allen, D. 2014. “Site Profiles for Atomic Weapons Employers that Worked Uranium Metals: 

Appendix BB – General Steel Industries,” Battelle-TBD-6000, Appendix BB, Revision No. 1. 

http://www.cdc.gov/niosh/ocas/pdfs/tbd/b-6000-apbb-r1.pdf 

Allen, D. 2015a. “Responses to Sanford Cohen & Associates Review of 

Battelle-TBD-6000 Appendix BB (General Steel Industries, Rev. 1),” Response Paper. 

http://www.cdc.gov/niosh/ocas/pdfs/dps/dc-gsiappbbr1-010815.pdf 

Allen, D. 2015b. “General Steel Industries Layout man Beta Skin Dose,” Response Paper. 

http://www.cdc.gov/niosh/ocas/pdfs/dps/dc-gsilaybeta-010815.pdf 

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

Uranium and Thorium Metals - Appendix BB: General Steel Industries,” Battelle-TBD-6000, 

Appendix BB, Rev. 0. 

Anigstein, R. 2011. “Update on the Use of Sealed Radioactive Sources at General Steel 

Industries.” http://www.cdc.gov/niosh/ocas/pdfs/abrwh/scarpts/sca-gsiradsrc.pdf 

Anigstein, R., and J. Mauro. 2013. “Review of Skin Dose Calculations for General Steel 

Industries.” Memo to Advisory Board on Radiation and Worker Health Work Group on TBD6000. http://www.cdc.gov/niosh/ocas/pdfs/abrwh/scarpts/sca-gsiskindose-120513.pdf 

Anigstein, R., and J. Mauro. 2014a. “Update of Doses from External Exposure at General Steel 

Industries.” Memo to Advisory Board on Radiation and Worker Health Work Group on TBD6000.” http://www.cdc.gov/niosh/ocas/pdfs/abrwh/scarpts/sca-gsiexdose-011214.pdf 

Anigstein, R., and J. Mauro. 2014b. “Review of ‘Site Profiles for Atomic Weapons Employers 

that Worked Uranium Metals Appendix BB – General Steel Industries,’ Revision 1.” 

http://www.cdc.gov/niosh/ocas/pdfs/abrwh/scarpts/sca-gsiapbbr1-121014.pdf 

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

Steel Industries: Dose Estimates for Betatron Operations’.” 

http://www.cdc.gov/niosh/ocas/pdfs/abrwh/scarpts/sca-gsibeta-r0.pdf 

Atomic Energy Commission (U.S.) (AEC). 1960. “Title 10—Atomic Energy; Chapter 1— 

Atomic Energy Commission: Part 20—Standards for Protection Against Radiation.” Federal 

Register, 25(224), 10914–10924. 

Review of NIOSH Response Paper No. 1 -7- SC&A – January 26, 2015
 

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.
 

 

 

International Commission on Radiological Protection (ICRP). 1997. “Conversion Coefficients 

for use in Radiological Protection against External Radiation,” ICRP Publication 74. Annals of 

the ICRP, 26 (3/4). Tarrytown, NY: Elsevier Science, Inc. 

Nuclear Regulatory Commission (U.S.) (NRC). 2009. “General Steel Industries Byproduct 

Materials License for Cobalt-60 Sealed Source not to exceed 1 curie.” ADAMS acquisition 

number ML093431334. 

Office of Compensation Analysis and Support (OCAS). 2004. “Technical Information Bulletin: 

Ingestion Intakes,” OCAS-TIB-009, Revision No. 0. 

http://www.cdc.gov/niosh/ocas/pdfs/tibs/oc-t9-ro.pdf 

Office of Compensation Analysis and Support (OCAS). 2007. “External Dose Reconstruction 

Implementation Guideline,” OCAS-IG-001, Revision No. 3. 

www.cdc.gov/niosh/ocas/pdfs/dr/oc-ig-001-r3.pdf 

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/sca-gsisp-r1.pdf 

Review of NIOSH Response Paper No. 1 -8- SC&A – January 26, 2015
 

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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.