SEC Petition Evaluation Report Supplement

Petition SEC-00006-1 

Rev. # 0 Submittal Date: 03-31-2005 

Petition Administrative Summary 

Petition Under Evaluation 

Petition # Petition 

Type 

Submittal Date DOE/AWE Facility Name 

SEC-0006 83.13 06-15-2004 Iowa Army Ammunition Plant 

Initial Class Definition 

Facility: Iowa Ordnance Plant (also known as the Iowa Army Ammunition Plant), Burlington, Iowa 

Locations: Line 1 (which includes Yard C, Yard G, Yard L, Firing Site Area, Burning Field “B”, and Storage 

Sites for Pits and Weapons including Buildings 73 and 77) 

Job Titles and/or Job Duties: All Technicians (Laboratory, Health Physics, Chemical, X-ray, etc.), Production 

Personnel, Physical Security Personnel (hourly and salaried), Engineers, Inspectors, Safety Personnel, Physical 

Security Personnel, and Maintenance Persons. 

Period of Employment: 1947-1974 

Proposed Class Definition 

NA 

Related Petition Summary Information 

SEC Petition Tracking #(s) Petition Type DOE/AWE Facility Name Petition Status 

SEC-00007 83.13 Iowa Army Ammunition Plant Merged with SEC-00006 

SEC-00014 83.13 Iowa Army Ammunition Plant Merged with SEC-00006 

SEC-00015 83.13 Iowa Army Ammunition Plant Merged with SEC-00006 

Prepared by: Signature on File 4/4/05 

Timothy D. Taulbee Date 

Reviewed by: Signature on File 4/4/05 

James W. Neton Date 

Approved By: Signature on File 4/4/05___

Larry J. Elliott Date 
Supplement to IAAP SEC Petition Evaluation Report 

(SEC-0006-1) 

Discussion of Issues Related to the Advisory Board’s Deliberation of the IAAP 

Evaluation Report on 2/09/2005 in St. Louis 

Introduction

During the Advisory Board on Radiation and Worker Health’s review of the SEC Petition 

Evaluation Report (SEC-00006-1) for the Iowa Army and Ammunition Plant (IAAP), the 

revised site profile (revision 1) for the IAAP had not yet been reviewed for classified 

material content by the Department of Energy (DOE). Since the time of the Board 

meeting, the DOE completed its review of the profile and NIOSH has approved revision 

1 for use in dose reconstructions. In addition, several issues were raised by petitioners at 

the February Board meeting that were not specifically addressed in NIOSH’s evaluation1

. 

This supplement to the IAAP Evaluation Report provides an evaluation of the effect the 

release of the revised site profile and the issues raised by petitioners might have on the 

proposed designation contained in the original Evaluation Report presented at the Board 

meeting. 

Issues 

1. Revision 1 of the IAAP site profile was reviewed by DOE and found to contain 

no classified information. How does this affect the transparency issues raised by 

NIOSH in the evaluation report?

2. The special exposure cohort evaluation relies on data from Pantex workers who 

were exposed between 1993 and 2003. The recent data collected at Pantex can 

not be considered as representative coworker data for IAAP workers. This 

information is from a different time period which employed different work 

processes

3. Workers recalled situations where the beryllium outer shells of the pits came off 

and would have to be glued back on the pit. This proves that workers handled 

bare plutonium pits which created the potential for internal exposure. 

4. Workers smeared the inside of a hollow sphere which consisted of what was 

known as “hot material.” This has implications regarding exposure to unshielded 

ionizing radiation and internal dose.

 

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Written comments on the SEC petition evaluation report, prepared by Dr. William Field of the University 

of Iowa, were provided to the Advisory Board by Dr. Laurence Fuortes during the meeting. Upon review, 

these comments were found to be substantially the same as those provided on pages 2 though 8 of the 

original petition. As such, these comments were previously considered during preparation of the SEC

Evaluation Report. 

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5. Even after 1962, a very low percentage of the workforce was monitored for 

radiation exposure. This does not provide enough data to make accurate exposure 

estimates.

Issue 1 

Revision 1 of the IAAP site profile was reviewed by DOE and found to contain no 

classified information. How does this affect the transparency issues raised by 

NIOSH in the evaluation report? 

When NIOSH presented the IAAP SEC petition evaluation report at the Board meeting in 

St. Louis on February 9, 2005, NIOSH advised the Board that the IAAP site profile 

document had been revised and was, at that time, undergoing classification review by 

DOE. NIOSH also indicated that the revised document (revision 1) would be provided to 

the Board and the public when this review had been completed and the document had 

been internally approved within the Office of Compensation Analysis and Support. 

NIOSH had access to all the information used to complete IAAP revision 1 at the time 

the SEC evaluation report was presented to the Board on February 9, 2005, but could not 

be certain that the manner in which this information was presented in revision 1 was not, 

itself, classified. Since the DOE review did not redact any information in the profile, 

NIOSH now believes that the profile, as it currently exists, allows for the transparent 

completion of dose reconstructions after 1962 for workers at IAAP.

Issue 2 

The special exposure cohort evaluation relies on data from Pantex workers who 

were exposed between 1993 and 2003. The recent data collected at Pantex can not 

be considered as representative coworker data for IAAP workers. This information 

is from a different time period which employed different work processes. 

The area monitoring devices at IAAP could not measure low energy neutrons which 

necessitated the use Monte Carlo N-Particle (MCNP) transport code calculations to 

reconstruct the low-energy (<800 keV) portion of the spectrum. Because of this, the 

recommended approach to estimating potential neutron doses for IAAP workers is to 

utilize the ratios of neutron-to-photon doses obtained from Pantex dosimeters during the 

period of 1993 through 2003. These dose ratios, represented as a distribution in the site 

profile, were calculated using data from the Pantex 809-812 dosimetry system which had 

gone through a formal accreditation program. Although these dosimeters were worn by 

workers, the absolute values of the measured doses, which depend to a large extent on 

work practices, were not used as part of this analysis. Rather, NIOSH used these devices 

to establish the ratio of neutron to photon doses from a given source term (i.e, the pits). 

Based on MCNP transport code calculations and Nuclear Track dosimeter Type A (NTA) 

measurements at IAAP, the measured Pantex neutron to photon ratio from 1993 through 

2003 is greater by a factor of approximately three than the actual IAAP neutron to photon 

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ratio. This difference is primarily due to the use of lead aprons at Pantex, which 

minimally affects the neutron dose but substantially reduces the total photon dose, 

thereby increasing the overall neutron to photon ratio. As a result, using the neutron-tophoton dose ratios based on the Pantex dosimeter measurements is more claimantfavorable than using the data measured at IAAP. 

Issue 3 

Workers recalled situations where the beryllium outer shells of the pits came off and 

would have to be glued back on the pit. This proves that workers handled bared 

plutonium pits which created the potential for internal exposure. 

As noted on page 25 of the SEC Petition Evaluation Report, all pits were clad, thus 

precluding the potential for internal exposure. This cladding is in addition to any 

beryllium outer shell material that may have encapsulated the pit. Therefore, if the 

beryllium cladding were removed, the radioactive pit material would still be 

encapsulated. At times, the cladding material may have been thin and warm to touch, 

giving workers the impression that they were handling bare radioactive metal while reattaching (gluing) other “cladding” materials. While this activity of reattaching the outer 

shells could increase the low energy external photon dose to the workers, the generic pit 

assumption outlined in the revised site profile more than compensates for such exposure 

potential. This is because the profile assumes there was no cladding at all on the pits and 

that the pits were in such a bare state 100 percent of the time, not simply that the outer 

shell was removed and re-attached on occasion. 

Issue 4 

Workers smeared the inside of a hollow sphere which consisted of what was known 

as “hot material.” This has implications regarding exposure to unshielded ionizing 

radiation and internal dose. 

During the Advisory Board on Radiation and Worker Health meeting an exposure 

potential was discussed in which workers would have to turn a component a certain way 

in order to reach inside the “hot material” and wipe out metal fragments. This is possible 

during final assembly of some In-Flight-Insertable (IFI) weapons systems. The operation 

involves removal of the explosive component from the ball to allow the capsule to be 

placed inside. During assembly operations, the fissile material (capsule) is not present. 

The “hot material” of the ball, if radioactive at all, would be composed only of nonenriched uranium. If the ball were uranium, the beta dose to the skin on the hand and 

forearm could be significant from this operation. The section on skin dose in the site

profile is currently listed as reserved and NIOSH is continuing further research to 

estimate skin dose from this operation. The external dose to the other organs of the body 

from this operation, however, would be very low and the generic pit assumption in which 

dose is estimated from fissile materials is much greater (orders of magnitude) than the 

photon dose that would have been received from this potential non-enriched uranium

source. 

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Issue 5 

Even after 1962, a very low percentage of the workforce was monitored for 

radiation exposure. This does not provide enough data to make accurate exposure 

estimates. 

At IAAP, the primary production process was the melting, casting, and testing of high 

explosives which did not involve the use of radioactive materials. Consequently, most 

workers at the plant would not have been monitored for radiation exposure. At most 

facilities throughout the AEC complex, only workers with a potential for radiation 

exposure have been monitored. While one could argue the robustness of this practice in 

that, by modern standards, some intermittent workers would probably have been 

monitored, dose reconstruction can be completed using co-worker data when the data 

represent a greater potential for exposure (higher potential dose levels) than would have 

been received by the unmonitored worker. 

In addition to the conventional explosives work at IAAP, the site was involved with the 

final assembly of the nuclear weapons. The radioactive components that constitute a 

nuclear weapon were made at other AEC facilities, including Rocky Flats, Y-12, LANL, 

LLNL, Sandia, Kansas City, Pinellas, and Mound. The IAAP simply assembled these 

components into the final configuration with the explosives. At IAAP, workers who 

routinely handled the most radioactive components (fissile materials) were routinely 

monitored post 1963. Based on a review of the records, workers who conducted other 

jobs (non-assembly) around the fissile materials generally were not monitored until about 

1968. As a result, at IAAP, the dose distribution developed from a moderate number of 

workers with the highest potential for exposure is considered claimant favorable, 

especially when applied to non-assembly Line 1 workers. 

 

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