SEC Petition Evaluation Report 

Petition SEC-00006-2 

Rev # 0 Submittal Date: 06-14-2005 

Petition Administrative Summary 

Petition Under Evaluation 

Petition # Petition 

Type 

Submittal Date DOE/AWE Facility Name 

SEC-00006 83.13 06-15-2004 Iowa Army Ammunition Plant 

Feasible to Estimate Doses with Sufficient Accuracy? 

Single Class Multiple Classes Determination Established for All Classes 

Yes X No Yes No X Yes X No 

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 (Abbreviated) 

Industrial radiographers who conducted radiography on non-radiological high explosive weapons components 

at the Iowa Ordnance Plant from May 1948-March 1949. 

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 

Lead Technical Evaluator: Signature on File 

Timothy D. Taulbee 

6/14/2005 

Date 

Reviewed By: Signature on File 

James W. Neton 

6/14/2005 

Date 

Approved By: Signature on File 

Larry J. Elliott 

6/14/2005 

Date 

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Evaluation Summary 

This evaluation report by the National Institute for Occupational Safety and Health 

(NIOSH) covers a subset of the employees proposed as a class for addition to the 

Special Exposure Cohort (SEC) in SEC Petition SEC00006, which was qualified for 

evaluation on October 20, 2004. The petition was submitted on behalf of all technicians 

(laboratory, HP, chemical, X-ray, etc.), production personnel (hourly and salary), 

engineers, inspectors, safety personnel, physical security personnel and maintenance 

persons working at the Iowa Army Ammunition Plant (IAAP) Line 1. On April 4, 2005, 

NIOSH completed its evaluation of this petition regarding all such employees except for 

a class comprising IAAP radiographers employed by Line 1 during the period from May 

1948 to March 1949. NIOSH required the additional information provided in this report 

to complete its evaluation of the petition with respect to this class of radiographers. 

Hence, this report completes the NIOSH evaluation of SEC Petition SEC00006. 

The evaluation report addresses the feasibility of estimating radiation doses with 

sufficient accuracy (i.e., the feasibility of dose reconstruction) and the evidence 

concerning the possible health endangerment for IAAP radiographers employed by Line 

1 during the period from May 1948 to March 1949. As discussed below, these two 

factors, the feasibility of dose reconstruction and health endangerment, govern decisions 

by the Department of Health and Human Services (HHS) on whether or not to designate 

a class of employees for addition to the SEC and on the definition of such classes. 

Feasibility of Dose Reconstruction 

The feasibility determination for the class of employees covered by this evaluation report 

is governed by 42 C.F.R. § 83.13(c)(1). Under this regulation, NIOSH must establish 

whether or not it has access to sufficient information to either estimate the maximum 

radiation dose, for every type of cancer for which radiation doses are reconstructed, that 

could have been incurred under plausible circumstances by any member of the class, or 

to estimate the radiation doses of members of the class more precisely than a maximum 

dose estimate. If NIOSH were to have access to the information sufficient for either 

case, then dose reconstruction would be feasible. 

NIOSH has established in this evaluation that it has insufficient information to estimate 

either the maximum radiation dose incurred by radiographers, or to estimate such 

radiation doses more precisely than a maximum dose estimate. The sum of information 

available from the site profile and additional resources is not sufficient to document or 

estimate the maximum external potential exposure to radiographers, under plausible 

circumstances during the period of radiological operations at IAAP, from May 1948 to 

March 1949. On this basis, NIOSH has determined that dose reconstruction is not 

feasible for radiographers at IAAP from May 1948 to March 1949. 

Health Endangerment 

The health endangerment determination for the class of employees covered by this 

evaluation report is governed by the Energy Employees occupational Illness 

Compensation Program Act of 2000 (EEOICPA) and 42 C.F.R. § 83.13(c)(3). Under 

these requirements, if it is not feasible to estimate with sufficient accuracy radiation 

doses for members of the class, NIOSH must also make a determination whether or not 

there is a reasonable likelihood that such radiation doses may have endangered the 

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health of members of the class. The regulation requires NIOSH to assume that any 

duration of unprotected exposure may have endangered the health of members of a 

class when it has been established that the class may have been exposed to radiation 

during a discrete incident likely to have involved levels of exposure similarly high to 

those occurring during nuclear criticality incidents. If the occurrence of such an 

exceptionally high level exposure has not been established, then NIOSH is required to 

specify that health was endangered for those workers who were employed for a number 

of work days aggregating at least 250 work days within the parameters established for 

the class or in combination with work days within the parameters established for one or 

more other classes of employees in the SEC. 

The NIOSH evaluation did not identify any evidence from the petitioners or from other 

sources that would establish that the class was exposed to radiation during a discrete 

incident likely to have involved exceptionally high level exposures, as described above. 

NIOSH is not aware of any report of such an occurrence at the facility. Evidence 

presented by the petitioner and uncovered by NIOSH associates the hazard to chronic 

exposures. Consequently, NIOSH has specified that health was endangered for those 

workers covered by this evaluation who were employed for a number of work days 

aggregating at least 250 work days within the parameters established for this class or in 

combination with work days within the parameters established for one or more other 

classes of employees in the SEC. 

Proposed Class Definition 

This evaluation defines a single class of employees for which NIOSH cannot estimate 

radiation doses with sufficient accuracy and whose health may have been endangered 

by such radiation doses. This class includes employees of DOE or DOE contractors or 

subcontractors employed by the IAAP who worked as radiographers from May 1948 to 

March 1949 in support of the Line 1 operations and whom were employed for a number 

of work days aggregating at least 250 work days occurring under this employment in 

combination with work days within the parameters (excluding aggregate work day 

requirements) established for classes of employees presently included in the SEC. 

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1.0 Purpose 

The purpose of this report for SEC Petition SEC00006 is to provide an evaluation of the 

feasibility of reconstructing the dose for a worker class at the Iowa Army Ammunition 

Plant (IAAP) in Des Moines County, near Middletown, Iowa who were employed from 

May 1948 to March 1949. 

NIOSH established in SEC Evaluation Report SEC-0006-1 that there were three 

separate classes of employees covered by petition SEC-00006: one class who worked 

from June 1947-May 1948, during which existing documentation indicated there were 

not any radioactive materials at the facility, nor any radiological exposures associated 

with the Atomic Energy Commission (AEC) work at the site; a second class composed of 

industrial radiographers who may have conducted radiography on non-radiological high 

explosive weapons components from May 1948-March 1949; and a third class 

comprising all employees at Line 1 of the facility from March 1949-1974. 

This report provides the results of NIOSH’s completed research to verify the existence of 

the class composed of industrial radiographers with employment at the Iowa Ordnance 

Plant (IOP) between May 1948 and March 1949. It also provides an evaluation of the 

feasibility of dose reconstructions for any members of this class and on the potential for 

the health of this class to have been endangered. 

This evaluation was conducted in accordance with the requirements of 42 C.F.R. pt. 83 

and the guidance contained in NIOSH’s Internal Procedures for SEC Evaluations, 

OCAS-PR-004. It provides information and analyses germane to considering a petition 

for adding a class of employees to the SEC. It does not provide any determinations 

concerning the feasibility of dose reconstruction that necessarily apply in the particular 

case of any individual energy employee who might require a dose reconstruction from 

NIOSH. 

2.0 Introduction 

Title 42 of the Code of Federal Regulations (C.F.R.), Part 83, Procedures for 

Designating Classes of Employees as Members of the Special Exposure Cohort Under 

the Energy Employees Occupational Illness Compensation Program Act of 2000, 

requires NIOSH to evaluate qualified petitions requesting HHS to add a class of 

employees to the SEC. The evaluation is intended to provide a fair, science-based 

determination of whether or not it is feasible to estimate with sufficient accuracy the 

radiation doses of the class of employees through NIOSH dose reconstructions1 . If it is 

not feasible, the evaluation is further required to make a determination with respect to 

the health endangerment of the class of employees. 

NIOSH is required to document the evaluation in a report, which is provided to the 

petitioners and to the President’s Advisory Board on Radiation and Worker Health (the 

Board). The Board will consider the NIOSH evaluation report, together with the petition 

and any comments of the petitioners(s), to make recommendations to the Secretary of 

HHS on whether or not to add one or more classes of employees to the SEC. Once 

NIOSH has received and considered the advice of the Board, the Director of NIOSH will 

1

 NIOSH dose reconstructions under EEOICPA are performed using the methods promulgated under 42 C.F.R. pt. 82 and 

the detailed implementation guidelines available at www.cdc.gov/niosh/ocas. 

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propose decisions on behalf of HHS. The Secretary of HHS will make final decisions, 

taking into account the NIOSH evaluation, the advice of the Board, and the proposed 

decision issued by NIOSH. As part of this final decision process, the petitioner(s) may 

seek a review of certain types of proposed decisions issued by NIOSH.2 

In this evaluation, NIOSH reviewed all available process information, radiation 

monitoring data, and source-term data for the period of time between May 1948 and 

March 1949 for the IAAP. The data were evaluated to determine if the quality and 

quantity of the measurements, process, and source term information are sufficient to 

support radiation dose reconstruction for this class. 

3.0 Initial Class Definition and Petition Basis 

The initial class definition specified in SEC Petition SEC00006 is: all technicians 

(laboratory, HP, chemical, X-ray, etc.), production personnel (hourly and salary), 

engineers, inspectors, safety personnel, physical security personnel and maintenance 

persons at the Iowa Ordnance Plant (also known as the Iowa Army Ammunition Plant), 

Burlington, Iowa that worked on 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) from 1947 to 1974. 

The basis cited in the petition is that radiation exposures potentially incurred by 

members of the petitioning class were not monitored, either through personal monitoring 

or through area monitoring. The petitioners contend that reconstruction of the 

radiological exposures received by members of the class with sufficient accuracy is not 

possible. As the basis for this belief, the petitioners provided affidavits and documents 

indicating that radiation exposures and doses to members of the proposed class were 

not monitored, either through personal or area monitoring, and that radiation monitoring 

records for members of the proposed class have been lost, falsified, or destroyed. One 

of the affidavits references the IAAP Technical Basis Document (TBD), the Pantex TBD 

and two technical reports. 

4.0 Data Resources 

To evaluate the petition, NIOSH reviewed available data sources for the existence of 

personal monitoring, area monitoring, industrial process, and radiological source 

information relevant to determining the feasibility of dose reconstruction for the class of 

employees covered by the petition. 

This information was retrieved from existing site profiles, Technical Information Bulletins 

(TIBs), dose reconstructions, internal databases containing personnel and area 

monitoring data, DOE records, NIOSH documents, other scientific reports, information 

gained through interviews with former workers, and information provided by the 

petitioners. 

2

 See 42 C.F.R. pt. 83 for a full description of the procedures summarized here. Additional internal procedures are 

available at www.cdc.gov/niosh/ocas. 

Page 5 of 10 
The following sections discuss the resources identified and reviewed. 

4.1 Site Profile or Technical Basis Documents 

A revised site profile exists for the IAAP. The site profile, Technical Basis Document for 

Atomic Energy Operations at the Iowa Army Ammunition Plant (IAAP) was reviewed. 

The site profile only covers radiological exposures during assembly and disassembly 

operations which began in March 1949 at IAAP. Prior to March 1949, the only 

operations that involved radiation exposure were radiographic operations in which 

explosive components were radiographed. 

4.2 NIOSH and ORAU Research Documents 

A search of the NIOSH and ORAU site research database (SRDB) was conducted for 

documentation relating to IAAP. All 162 IAAP related documents on the database were 

evaluated for relevance to the radiographers. These documents contained external 

dosimetry measurement results (for both IAAP and Pantex), annual Department of 

Defense (DoD) dosimetry reports, pocket ionization chamber logs, air sample results, 

survey reports, site incident reports, standing operating procedures, effluent data, and 

radon measurements. A needs assessment conducted by the University of Iowa, 

College of Public Health, and a significant number of the transcripts of interviews with 

former site employees, also in the holdings of the SRDB, provided important information 

concerning the exposure and operational history of the site. 

The information from these documents relevant to the class, as evaluated in this report, 

is summarized in sections 5.0 and 7.0 of this report. 

5.0 Summary of Available Monitoring Data 

Dosimetry programs were implemented in phases in conjunction with the development of 

the nuclear weapons work at IAAP. External dosimetry monitoring was not implemented 

until 1955. Thus, during the time period from May 1948 to March 1949 individual 

dosimetry information is not available. 

Subsequent records searches to date have also not identified any detailed information 

concerning the radiographic process, equipment or procedures during this early time 

period. According to Poole and Harrison (1954), gammagraph and radiograph facilities 

were required for inspection operations. 

Gammagraph and radiograph facilities were required for inspection operations 

and for accumulation of data from which adjustments could be made where 

necessary in production procedures. Since the initial operation was Baratol 

production, the gammagraph facility, utilizing a radium source, was given first 

priority. The facilities required consisted essentially of adequate shielding and 

safety devices for protection of personnel. (Poole and Harrison, 1954) 

NIOSH does have access to dosimetry data on radiographers beginning in 1955. 

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6.0 Summary of Radiological Operations Relevant to the Initial Class 

The IAAP is a government-owned, contractor operated, military-industrial installation that 

was established initially for the loading, assembly and packing of 75MM and 155MM 

artillery shells and 100 pound bombs. The IAAP site was historically shared with the 

DoD. Construction of the plant began in January 1941. On August 5, 1947 the Silas 

Mason Co. (Mason & Hanger-Silas Mason Co., Inc.) was contracted to complete 

rehabilitation of Line 1 and the construction of new facilities on behalf of the AEC. The 

phase one construction was completed in late 1948. In May 1948, the Silas Mason 

Company sent supervisors of production personnel to the Naval Ordinance Test Site at 

China Lake, California for training on the production of high explosives (Poole and 

Harrison, 1954). Upon completion of the training, these supervisors trained production 

personnel at the Iowa Ordinance Plant. Within a year, the Burlington Plant was at full 

production for high explosives fabrications and plans were underway to begin assembly 

of non-nuclear components, duplicating the assembly capabilities of Sandia (Mitchell, 

2003). Based on this information the earliest date that explosive component 

manufacturing for the Mark IV could have commenced at IAAP was May 1948. 

In March of 1949, AEC decided that certain weapons assembly operations would be 

conducted at the Iowa Ordinance Plant (Poole and Harrison, 1954). According to DOE's 

Office of Worker Advocacy, nuclear weapons assembly operations that were performed 

at Los Alamos and Sandia were transferred to the Iowa Ordnance Plant by 1949 (DOE 

Website 2005). In 1949, Silas Mason accepted responsibility for operation of highly 

classified facilities, known locally as Division B. 

During this early time period (May 1948 – March 1949), radiography was conducted as 

part of the non-destructive quality control analysis explosive components. Radiography 

was the only radiological work conducted at IAAP prior to the first assembly of nuclear 

weapons in March 1949. 

Building 1-73 

Building 1-73 was used as a gammagraph and radiograph facility. This building was 

used for inspection operations and necessary for production procedures. The building 

was designed to provide adequate shielding and safety devices for protection of 

personnel (Poole and Harrison, 1954). Interlocks and physical barriers were designed to 

shield workers from radiation exposures associated with the inspection equipment. 

7.0 Evaluation of Feasibility of Dose Reconstruction 

7.1 Internal Dose 

Radiography at IAAP involved the use of sealed radioactive sources and / or radiation 

generating devices. Since the sources were sealed, there was no potential for internal 

radiation exposure from the radiography equipment. Since assembly of nuclear 

weapons was not conducted until March 1949, radiographic operations between May 

1948 and March 1949 would have been conducted entirely on non-radioactive high 

explosive components. Therefore, there would not have been any potential for internal 

exposure prior to March 1949. 

Page 7 of 10 
7.2 External Dose 

NIOSH evaluated whether dosimetry from later time periods (1955) could be used as a 

surrogate for the early time period. To use this potential surrogate data, NIOSH would 

require a means to validate that radiographic operations did not change substantially 

between 1948 and 1955. Because NIOSH lacks process information on this early period 

of radiography, it is not possible to validate that the operations were comparable. 

Furthermore, a review of both classified and unclassified records could not even 

establish the actual number of radiographs conducted during early and later time periods 

at IAAP, let alone component-specific procedural details, which would also be required 

for the use of surrogate data from the later period. As a result, dose reconstruction 

during this early time period is not feasible based on monitoring data. 

Dose reconstruction might also be feasible if NIOSH could use a combination of process 

and radiological source information. However, as discussed above, NIOSH lacks any 

substantive process information for the period of concern. Furthermore, NIOSH does 

not have information on the radiation source strength and shielding used during this 

period. This information would be essential. 

For example, a review of early radiographer exposures at a naval shipyard indicates that 

average exposures were on the order of 100 - 200 mrem per week (Daniels et al., 2004). 

If IAAP radiographers had similar equipment, shielding and procedures, over the 9 

month period between May 1948 and March 1949, the total external dose to IAAP 

radiographers could have been at a minimum in the 4,000 to 8,000 mrem range. 

However, the actual doses experienced by early IAAP radiographers could have been 

higher or lower than the recorded doses of shipyard workers. This depends, in part, on 

the volume of work. Furthermore, if shielding was less effective and the radiation source 

strength was significantly greater than that used at the shipyard, the values could be an 

order of magnitude or more higher at IAAP. Conversely, the actual dose could have 

been significantly lower than that experienced by the shipyard workers, if effective 

training had been conducted and experienced workers conducted the first radiographs. 

In later years, there is evidence that shielding and safety devices were included in the 

design of the main radiography building (1-73) at IAAP. NIOSH has not been able to 

determine, however, when Building 1-73 was built. Since virtually no information is 

available on the radiography practices, equipment, and source strength at IAAP during 

the period in question, it is not feasible to estimate an upper bound on the potential 

external dose incurred by IAAP radiographers. 

In summary, information available to NIOSH is insufficient for dose reconstructions 

based on either dosimetry and process data or process and radiological source 

information. Accordingly, it is not feasible to estimate with sufficient accuracy the 

external radiation doses potentially incurred by radiographers at IAAP during the period 

evaluated in this report. 

8.0 Health Endangerment 

The health endangerment determination for the class of employees covered by this 

evaluation report is governed by EEOICPA and 42 C.F.R. § 83.13(c)(3). Under these 

requirements, if it is not feasible to estimate with sufficient accuracy radiation doses for 

members of the class, NIOSH must also determine that there is a reasonable likelihood 

Page 8 of 10 
 

that such radiation doses may have endangered the health of members of the class. 

The regulation requires NIOSH to assume that any duration of unprotected exposure 

may have endangered the health of members of a class when it has been established 

that the class may have been exposed to radiation during a discrete incident likely to 

have involved levels of exposure similarly high to those occurring during nuclear 

criticality incidents. If the occurrence of such an exceptionally high level exposure has 

not been established, then NIOSH is required to specify that health was endangered for 

those workers who were employed for a number of work days aggregating at least 250 

work days within the parameters established for the class or in combination with work 

days within the parameters established for one or more other classes of employees in 

the SEC. 

As discussed in Section 7.2 of this report the doses to radiographers during the 9 month 

period could have exceeded 8,000 mrem. On this basis, NIOSH has determined that it 

is reasonably likely that such exposures may have endangered the health of the IAAP 

employees covered by the class definition provided in section 9.0 of this evaluation. 

The NIOSH evaluation did not identify any evidence from the petitioners or from other 

resources that would establish that the classes were exposed to radiation during a 

discrete incident or similar conditions resulting from the failure of radiation exposure 

controls and likely to have produced levels of exposure similarly high to those occurring 

during nuclear criticality incidents. NIOSH is not aware of any report of such an 

occurrence at the facility. The evidence reviewed in this evaluation indicates that some 

workers in the classes may have accumulated substantial doses through chronic 

exposure to external sources of radiation. Consequently, NIOSH is specifying that 

health was endangered for those workers covered by this evaluation who were 

employed for a number of work days aggregating at least 250 work days within the 

parameters established for this class in combination with work days within the 

parameters established for one or more other classes of employees in the SEC. 

9.0 Proposed Class Definition 

This evaluation defines a single class of employees for which NIOSH has established 

that it cannot estimate radiation doses with sufficient accuracy and whose health may 

have been endangered by such radiation doses. The class only includes employees 

whose job title was radiographer working at the IAAP Line 1, which includes Yard C, 

Yard G, Yard L, Firing Site Area, Burning Field “B” and Buildings 73 and 77, from May 

1948 to March 1949, and whom were employed for a number of work days aggregating 

at least 250 work days occurring under this employment in combination with work days 

of employment occurring within the parameters (excluding aggregate work day 

requirements) established for other classes of employees included in the SEC. 

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10.0 References 

Daniels et al. (2004) 

Daniels, R.D., Taulbee, T.D., Chen, P., (2004) “Radiation Exposure Assessment for 

Portsmouth Naval Shipyard Health Studies,” Radiation Protection Dosimetry, Vol. 111, 

No. 2, pp. 139-150. 

Mitchell (2003) 

Mitchell, Kris C. (2003) Rhetoric to Reality: A Cold War Context Statement for the 

Pantex Plant (1951-1991) BWXT Pantex, LLC. 

Poole and Harrison (1954) 

Silas Mason Company, Inc. “Project History of Line 1 Operations at Iowa Ordnance 

Plant January 1, 1947 – July 1, 1954” Contract No. W-49-010-ORD-68. This report is a 

project history to record the initial rehabilitation, construction and activation of the 

facilities of Line 1. October 1954. Document File Location: IAAP\08-28-03 – Data 

Capture\010001487\Project History of Line 1 Operations January 1947 Through June 

1954.pdf. 

ORAUT-TKBS-0018 (2005) 

ORAU Team NIOSH Dose Reconstruction Project (ORAUT) “Technical Basis Document 

for Atomic Energy Operations at the Iowa Army Ammunition Plant (IAAP)” Rev 1, 

ORAUT-TKBS-0018; 03/14/2005. 

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