DTRA / NTPR - Standard Operating Procedures Manual 

RA06 – Radiation Dose Assessment for Participants in the Enewetak Cleanup Project 

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Date: February 15, 2022 

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DEFENSE THREAT REDUCTION AGENCY 

NUCLEAR TEST PERSONNEL REVIEW PROGRAM 

RADIATION DOSE ASSESSMENT 

STANDARD OPERATING PROCEDURE 

RA06 – Radiation Dose Assessment for Participants 

in the Enewetak Cleanup Project 

Revision 1.2 

Cleared for Release 

Key to SOP ID Codes 

RA (Radiation Assessment - SOP) 

ED (External Dose - Standard Methods) 

ID (Internal Dose - Standard Methods) 

UA (Uncertainty Analysis - Standard Methods) 
 

 

 

 

 

 

 

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Revision Control 

Revision Revision Description Revision 

Date 

Authorization 

Official 

1.0 Original version 11/15/2019 James D. Franks 

1.1 - Section 5.6: changed the content of the pathways’ bullets separating 

out ingestion of local food and ingestion of drinking water 

- Updated the publication year of the ECUP Technical Report, 

Revision 1, from 2019 to 2020, throughout 

- Other editorial changes 

04/30/2021 James D. Franks 

1.2 - Changes made in Sections 4 and 5 to report skin doses and upperbound skin doses by radiation type as an alpha dose and a 

beta+gamma dose 

- Added a default local food in Table A1-6 

- The RDA Report template was revised to reflect the reporting of 

separate skin doses by radiation type. The revised template includes 

editorial changes needed to clarify and improve the text 

- Other editorial changes 

02/15/2022 James D. Franks 
 

 

 

 

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Table of Contents 

1. Purpose/Summary ................................................................................................................ 6 

2. Scope ................................................................................................................................... 6 

3. Responsibilities .................................................................................................................... 7 

4. Definitions ........................................................................................................................... 7 

5. Procedure: Detailed Activity/Task Description..................................................................... 8 

5.1 Review Case Information .............................................................................................9 

5.2 Collect Additional Information .....................................................................................9 

5.3 Identify Exposure Scenario and Define Exposure Pathways........................................10 

5.4 Obtain RDA Team Consensus on Scenario of Exposure and Pathways .......................10 

5.5 Assess External Whole Body Dose .............................................................................10 

5.5.1 Dose Assessment Hierarchy ...............................................................................10 

5.5.2 Conduct Dosimetry Records Analysis ................................................................11 

5.5.3 Calculate Additional External Whole Body Doses..............................................11 

5.5.3.1 Characterize Radiation Environment ......................................................12 

5.5.3.2 Identify Project Tasks and Activities with Potential for Radiation 

Exposure ................................................................................................12 

5.5.3.3 Compile Assumptions and Input Parameters...........................................13 

5.5.3.4 Estimate Doses by Reconstruction..........................................................13 

5.5.4 Calculate Total Whole Body External Dose and Upper-Bound Dose ..................13 

5.6 Assess Dose from Intakes of Radioactive Materials ....................................................14 

5.7 Assess Doses to the Skin.............................................................................................15 

5.8 Prepare Internal Draft RDA Report.............................................................................16 

5.9 Perform Reviews ........................................................................................................16 

5.10 Prepare Final Draft RDA Report.................................................................................17 

5.11 Transmit RDA Report.................................................................................................17 

5.12 Receive DTRA PM Review Comments ......................................................................17 

5.13 Transmit Revised Final Draft RDA Report .................................................................17 

6. Data and Records Management ...........................................................................................18 

7. Quality Assurance and Quality Control ...............................................................................18 
 

 

 

 

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8. Referenced SOPs from the NTPR/RDA SOP Manual..........................................................19 

9. References...........................................................................................................................19 

Attachment 1. Default Dose Parameter Values to Use in Radiation Dose Assessments for ECUP 

Participants ........................................................................................................20 

Attachment 2. Template of a Standard RDA Report for Participants in the Enewetak Cleanup 

Project ...............................................................................................................39 

Attachment 3. Technical Review Checklist for Radiation Dose Assessments for Participants in 

the Enewetak Cleanup Project............................................................................47 
 

 

 

 

 

 

 

 

 

 

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List of Tables 

Table A1-1. General default parameter values for external dose assessments for ECUP 

participants ........................................................................................................21 

Table A1-3. Averaging methods to determine exposure rates or soil activity concentrations for 

Table A1-6. General default parameter values for internal dose assessments for ECUP 

Table A1-7. Estimated activity concentration of contaminated soil excised and moved to 

Table A1-9. Inhalation dose coefficients for use in internal dose assessments for ECUP 

Table A1-10. Ingestion dose coefficients for use in internal dose assessments for ECUP 

Table A1-12. General default parameter values for use in non-contact skin dose assessments for 

Table A1-13. Beta-to-gamma dose ratios for external non-contact radiation sources for all 

Table A1-15. General default parameter values for use in dermal contamination skin dose 

Table A1-16. Radionuclide-dependent and skin site-dependent default parameter values for use 

Table A1-2. External exposure rates and surface soil activity concentrations for all islands ...22 

scenarios where ECUP veterans worked on multiple islands ..............................24 

Table A1-4. ECUP participant debris cleanup volumes at Enewetak Atoll .............................25 

Table A1-5. Time spent outdoors and indoors on residence islands........................................27 

participants ........................................................................................................28 

Cactus crater and dome ......................................................................................29 

Table A1-8. ECUP personnel protection levels and respiratory protection factors 29 

participants ........................................................................................................30 

participants ........................................................................................................32 

Table A1-11. Organ doses from potential consumption of local food by ECUP participants.....34 

ECUP participants..............................................................................................35 

islands at Enewetak Atoll...................................................................................36 

Table A1-14. Reference heights of body locations from surface...............................................36 

assessments for ECUP participants.....................................................................37 

in dermal contamination skin dose assessments for ECUP participants...............38 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

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Standard Operating Procedure 

RA06 – Radiation Dose Assessment for Participants in the Enewetak 

Cleanup Project 

1. Purpose/Summary 

This standard operating procedure (SOP) provides the detailed activities and tasks 

required to perform radiation dose assessments (RDAs) and prepare RDA Reports for 

veterans who participated in the radiological cleanup of the Enewetak Atoll known as the 

Enewetak Cleanup Project (ECUP) from 1977 to 1980. This SOP addresses the 

evaluation of radiation doses to the whole body and skin from external exposure, and to 

internal organs from the intake of radioactive material by inhalation, ingestion, and 

wound absorption. The procedure requires the adaptation of existing dose calculation 

tools or development of new modules to calculate the radiation doses, along with 

associated uncertainties and upper-bound doses, for a range of activities performed by a 

participant in various ECUP radiation environments. It requires the preparation of a dose 

calculation worksheet personalized to a specific participant’s activities and radiation 

environments, organs and diseases considered, and affected skin locations in the case of 

skin cancers. 

This SOP is written for qualified RDA analysts to perform required tasks using the 

methods described in a technical report published by the Defense Threat Reduction 

Agency (DTRA, 2020a). Tasks include the modification or development of dose 

calculation tools and preparation of an RDA Report that is specific to a veteran who files 

a claim with the Department of Veterans Affairs (VA) for service-connected diseases. 

This SOP also describes quality control activities performed by technical and 

management personnel to ensure conformance with approved procedures and methods, as 

well as established policies and guidelines of the Nuclear Test Personnel Review (NTPR) 

Program administered by DTRA. 

2. Scope 

This SOP applies to veteran ECUP participants filing claims with the VA for serviceconnected diseases. The Population of Interest (POI) consists of about 6,000 military 

service members who participated in ECUP within the period 1977 to 1980. The POI 

includes members of the three military service components of the ECUP Joint Task 

Group (JTG) consisting of the Army, Navy, and Air Force Elements, as well as personnel 

of the Defense Nuclear Agency (DNA)/JTG itself. This SOP employs approved and 

published dose estimation methods and documented data that address all aspects of 

radiation dose assessments. The DoD objectives for radiation dose determinations in 

32 CFR 218 have been adapted to apply to ECUP radiation dose assessments (DoD, 

2020). The methods, data, and references developed for ECUP RDAs are incorporated in 

a DTRA technical basis document entitled “Radiation Dose Assessment for Military 
 

 

 

 

 

 

 

 

 

 

 

 

 

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Personnel of the Enewetak Atoll Cleanup Project (1977–1980), Revision 1” (DTRA, 

2020a). Radiation dose assessments for ECUP participants prepared according to this 

SOP provide full consideration of benefit of the doubt throughout the dose assessment 

process as required by the VA in 38 CFR 3.102 (VA, 2020). 

3. Responsibilities 

A qualified radiation dose analyst (the RDA Analyst) is assigned the case and performs 

most tasks required for analyzing the radiation exposure activities, calculating radiation 

doses, and preparing the RDA Report. The RDA Analyst also consolidates retrieved 

information and management of RDA case files as needed. A second radiation dose 

analyst conducts technical reviews for quality control. Management personnel perform 

additional quality control reviews to ensure that work products submitted to the DTRA 

Program Manager (PM) are consistently prepared to conform to publication guidelines, 

templates, and content specifications. 

4. Definitions 

AEC U.S. Atomic Energy Commission: federal nuclear regulatory 

entity 1946–1974; nuclear regulatory functions were assumed by 

the Nuclear Regulatory Commission and other functions by other 

predecessor organizations to the current Department of Energy in 

1975 

Bioassay Measurements performed to determine the amount of radioactive 

material in the human body 

CFR Code of Federal Regulations 

DoD Department of Defense 

Dose component Potential contributor to an individual’s overall organ dose, 

including: 

- External gamma dose 

- Inhalation dose – alpha and beta+gamma radiation 

- Ingestion dose – alpha and beta+gamma radiation 

DTRA Defense Threat Reduction Agency: the DoD agency that 

manages and operates the NTPR Program 

DTRA PM Program Manager assigned by DTRA that is responsible for 

managing the NTPR program 

ECUP Enewetak Cleanup Project: the project for the radiological 

cleanup of Enewetak Atoll conducted from 1977 to 1980 

JTG Joint Task Group: a multi-service military group formed to 

accomplish a specific task 
 

 

 

 

 

 

 

 

 

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Management Review Final review conducted by the RDA Analyst manager before the 

Final Draft RDA is forwarded to the DTRA PM 

NTPR Nuclear Test Personnel Review: the DoD/DTRA program that 

confirms participation and estimates doses for atomic veterans, 

and is also responsible for preparing ECUP RDAs 

NuTRIS Nuclear Test Research Information System: a computerized 

database containing veteran information and dosimetry data 

QA Quality Assurance: the process and procedures by which 

requirements and activities are defined to demonstrate that work 

products conform to NTPR SOPs 

QC Quality Control: reviews, audits, and discussions conducted to 

verify the accuracy of NTPR results and work products and their 

compliance with SOPs, SMs, and other specific program 

requirements 

RDA Radiation Dose Assessment: a complete analysis and estimation 

of potential radiological doses to an individual 

RDA Analyst Radiation Dose Assessment Analyst: an individual qualified to 

conduct or review RDAs 

Skin dose External dose from alpha and beta+gamma radiation 

SM Standard Method: NTPR document that provides technical and 

computational methods for specific aspects of assessing doses 

and dose distributions to include upper bounds 

SOP Standard (or Standing) Operating Procedure 

Surrogate organ An ECUP standard organ used for dose calculations as a 

substitute organ when no published dose coefficients are 

available for the requested disease or medical condition 

VA Department of Veterans Affairs 

5. Procedure: Detailed Activity/Task Description 

A radiation dose assessment for an ECUP participant starts with a review of the veteran’s 

ECUP Questionnaire and case file. The case file includes the VA request for dose 

information, military service records, dosimetry records, military orders, Enewetak Atoll 

arrival/departure cards, and may also include (as applicable) the veteran’s statements, 

island access cards, boat logs, relevant excerpts from published reports, and other 

pertinent documentation. The assessment then proceeds with dose and upper-bound dose 

calculations, and preparation of the RDA Report. Doses are based on either recorded 

dosimetry from film-badges and thermoluminescent dosimeters (TLD) or calculations 

using dose reconstructions methods. Dose estimates determined by dose reconstruction 
 

 

 

 

 

 

 

 

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are performed using standard analytical methods with documented assumptions, 

environmental data, and other dose parameter values that are published in a DTRA 

technical report (DTRA, 2020a). 

As stated in Section 2, radiation dose assessments provide full consideration of benefit of 

the doubt throughout the dose estimating process. To do so, radiation dose analysts rely 

on veteran’s statements and use them unless the statements involve activities that are not 

plausible or are refuted by documented records. High-sided parameter values and 

assumptions that reasonably maximize the veteran’s dose are employed in calculations of 

dose and upper-bound doses using fixed uncertainty factors (DTRA, 2020a). This section 

provides the steps used to conduct an ECUP radiation dose assessment and prepare 

veteran-specific dose calculations and an RDA Report. 

5.1 Review Case Information 

The RDA Analyst, to whom a case is assigned, reviews the case file for a veteran’s 

responses to the ECUP Questionnaire and the VA letter request for dose information to 

identify the diseased organs, skin sites, and other medical conditions. The RDA Analyst 

reviews other case materials, project reports, previously completed veterans’ RDA 

Reports, the ECUP records collection, and any other available documentation and 

publications to the extent necessary to determine: 

• Whether all required information is available to carry out the dose assessment 

• Whether any conflicts or inconsistencies exist between the documented records, 

publications, and the veteran’s statements 

• If any additional information is available from other case files of veterans engaged in 

similar ECUP activities in the same locations. 

5.2 Collect Additional Information 

If additional information is needed to complete gaps in the case file or resolve 

inconsistencies, the RDA Analyst: 

• Requests searches for specific information of/from the ECUP records collection, the 

NuTRIS database or other document repositories, such as the Nuclear Testing 

Archive in Las Vegas, NV and the National Personnel Records Center in St. Louis, 

MO 

• Identifies additional questions for the veteran to answer via the program’s veteran 

assistance unit (DTRA, 2020b; DTRA, 2020c). 
 

 

 

 

 

 

 

 

 

 

 

 

 

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5.3 Identify Exposure Scenario and Define Exposure Pathways 

Radiation doses are estimated based on scenarios that characterize the veteran’s ECUP 

activities within radiation environments. In particular, the RDA Analyst identifies ECUP 

task teams and associated exposure scenarios, as described in DTRA (2020a). 

Radiation exposures are defined in terms of pathways of exposure each involving a 

source of radiation, a mechanism (pathway) for the radiation to reach the exposed 

individual, and, for internal dose assessment, a route of entry into the body. Exhaustive 

lists of project tasks and activities with associated radiation sources and exposure 

pathways are presented in DTRA (2020a) and are reproduced in the sub-sections below. 

5.4 Obtain RDA Team Consensus on Scenario of Exposure and Pathways 

After identifying the scenario of radiation exposure and defining relevant exposure 

pathways by compiling all available information about the veteran’s participation, the 

RDA Analyst consults with members of the RDA team and discusses all case findings 

and proposed resolutions to complete the dose assessment. These RDA team discussions 

should result in recommendations to the RDA Analyst to proceed with the proposed 

decisions, assumptions, and dose parameter input values that are specific to the veteran, 

or to make modifications to better characterize the scenario of exposure and related 

pathways. If modifications are recommended, the RDA Analyst iterates with the other 

RDA team members to complete all necessary changes and obtain consensus to proceed 

with the veteran’s RDA. 

5.5 Assess External Whole Body Dose 

External whole-body exposure represents the most common source of potential radiation 

dose for ECUP veterans who performed duties on contaminated islands identified for 

cleanup. The island average gamma radiation exposure rates from measurements 

conducted during the 1972 AEC radiological survey of the Enewetak Atoll islands (AEC, 

1973) are presented in Table A1-2. Also, personnel dosimetry records may be available 

from the ECUP document collection and military services dosimetry centers. 

5.5.1 Dose Assessment Hierarchy 

External radiation doses are determined using the following hierarchy of methods: 

• Valid dosimetry results for the individual, normally from film badge and TLD records 

• Reconstructed doses obtained using sound scientific methods and a knowledge of the 

activities and radiation environments to which the individual was exposed when 

individual dosimetry is unavailable or unreliable. 
 

 

 

 

 

 

 

 

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5.5.2 Conduct Dosimetry Records Analysis 

The validity and applicability of dosimetry records is a critical aspect of the analysis. The 

various sources for the records are contained in the following documents and files: 

• DD Form 1141 “Record of Occupational Exposure to Ionizing Radiation” 

• Army Dosimetry Center (ADC) (formerly called LBDA) database 

• Department of Army (DA) Form 3484 “Photodosimetry Report” 

• Thermoluminescent Dosimetry (TLD) Report 

• TLD Control Card. 

The review of dosimetry records for ECUP veterans is performed by the RDA Analyst 

according to the following guidelines to determine their validity and applicability: 

• The DD Form 1141 is the official document used by the Military Services to record 

radiation doses to personnel engaged in radiation work and should be used as the 

primary source of dosimetry records 

• Reported film badge doses of 20 mrem or less should be superseded with 

reconstructed doses for the applicable wearing periods 

• Administrative doses reported in dosimetry records should be superseded with 

reconstructed doses for the applicable periods; these include administrative doses that 

were substituted for doses from damaged film badges 

• Doses from undamaged film badges that are higher than 20 mrem and all TLD 

readings should be used as components of the external dose to the veteran for the 

reported wearing periods 

• A TLD dose takes precedence over a film badge dose that covers the same wearing 

period because of the finer resolution and accuracy of the TLDs and reading system. 

For time periods not covered by valid dosimetry records, radiation doses are estimated 

using dose reconstruction techniques as described in the following section. 

5.5.3 Calculate Additional External Whole Body Doses 

The RDA Analyst determines time periods during the individual’s ECUP assignment for 

which reliable dosimetry records are not available. Radiation doses for these periods are 

assessed using reconstruction techniques described in this section. 
 

 

 

 

 

 

 

 

 

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5.5.3.1 Characterize Radiation Environment 

Radiation dose assessments require that the radiation environments be properly defined 

and characterized by potential sources and pathways. Direct exposure to the radiation 

emitted by radioactive contamination is the primary pathway of external exposure 

relevant to ECUP personnel. Sources of radiation that may have resulted in direct 

exposure to radiation of ECUP participants include the following: 

• Ground surface contaminated with fallout mixed in the top layer of soil 

• Slurry of mixed contaminated soil and cement during preparation, transport, and 

disposal in the Cactus crater 

• Stockpiles of contaminated soil and debris 

• Contaminated soil and metal scrap debris during transport by trucks and boats 

• Contaminated concrete structures and slabs and building debris 

• Soil-cement mix produced and contained in the Cactus dome 

• Lagoon water, lagoon sediment, and ocean water while personnel retrieved debris 

from offshore locations and during diving or recreational swimming; see note below 

• Contaminated equipment 

• Contaminated laundry at the decontamination laundry facility. 

Note: For the pathway of external exposure while immersed in lagoon or 

ocean water, maximized doses have been estimated to be orders of magnitude 

below 1 mrem using conservative assumptions. Therefore, doses from this 

pathway are subsumed within applied upper-bound dose uncertainties with no 

need to estimate them separately. (DTRA, 2020a) 

Detailed descriptions of potential sources of external radiation and pathways are provided 

in DTRA (2020a). 

5.5.3.2 Identify Project Tasks and Activities with Potential for Radiation Exposure 

Based on the review of the returned questionnaire and the VA statement of claim (if 

included) combined with information in operational records, the RDA Analyst develops 

the veteran’s detailed activities and considers external sources of gamma radiation in the 

following ECUP activities: 

• Soil cleanup 

• Debris cleanup 

• Radiological support 

• Project activities on the southern islands (except Enewetak Island) 
 

 

 

 

 

 

 

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• Project support on the residence island of Enewetak 

• Project support on the forward residence island of Lojwa 

• Intra-atoll transport 

• Pre-cleanup and demobilization activities 

• Recovery and disposal of unexploded ordnance by Explosive Ordnance Disposal 

teams. 

5.5.3.3 Compile Assumptions and Input Parameters 

The scenario description in the RDA Report includes statements of all significant 

assumptions required to complete the dose assessment. When details of the components 

cannot be determined from the veteran’s responses to the questionnaire or other pertinent 

documentation, activities must be assumed. In rare cases, it might be necessary for the 

RDA Analyst to ask the veteran to answer additional questions. 

5.5.3.4 Estimate Doses by Reconstruction 

The RDA Analyst uses the methods described in DTRA (2020a) and related dose 

calculation tools to reconstruct doses from each source of external radiation. The RDA 

Analyst estimates the veteran’s doses from external radiation sources and pathways based 

on activities described in the case file and pertinent historical records and reports. 

In particular, the RDA Analyst uses island exposure rate data compiled in Section 4 and 

other dose parameter values reported in Section 6 of DTRA (2020a) to estimate external 

doses for most ECUP veterans. The island exposure rate data were derived from the 1972 

radiological survey of ground contamination from previously deposited fallout (AEC, 

1973) and are incorporated in ECUP RDA calculation tools. 

Default dose parameter input values reported in DTRA (2020a) are compiled in 

Attachment 1 and should be used in the external dose calculations in the absence of 

veteran-specific exposure information and data. The default input values compiled in 

Attachment 1 are based on information documented and extracted from ECUP historical 

reports and other documentation. Additional details on assumptions and high-sided 

parameter values can be found in DTRA (2020a). 

For exposure scenarios for which no calculation tools specific to ECUP are available, 

RDA analysts must develop the necessary worksheets for the relevant dose assessment. 

5.5.4 Calculate Total Whole Body External Dose and Upper-Bound Dose 

Available dose calculation tools generate total external doses and upper-bound doses in 

accordance with the methods included in DTRA (2020a). The total and upper-bound 

doses combine doses from film badges, TLDs, and reconstruction of individual scenario 
 

 

 

 

 

 

 

 

 

 

 

 

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components. Newly developed worksheets must include calculation of total and upperbound doses using the methods presented in DTRA (2020a). 

5.6 Assess Dose from Intakes of Radioactive Materials 

The RDA Analyst reviews the request for a dose assessment and determines the internal 

organ(s) of interest. If dose coefficients are not available for an organ of interest, a 

surrogate organ is substituted in the dose assessment. A surrogate organ is similar to the 

organ of interest with respect to its biokinetic modeling (see NTPR SOP RA07, 

Attachment 1 for guidance in determining surrogate organs). 

Over 2,300 24-hour urine samples were analyzed during ECUP. When available, the 

RDA Analyst reviews the veteran’s urine bioassay results to verify that they are in the 

range reported in DNA (1981). However, these results are not used for internal dose 

estimation as discussed in DTRA (2020a). Consequently, the RDA Analyst estimates 

doses from internal exposure pathways using the methods described in DTRA (2020a) 

and available or newly developed dose calculation tools. 

The RDA Analyst considers the following pathways to the internal or surrogate organs 

for internally deposited radioactive material: 

• Inhalation of suspended soil 

• Incidental ingestion of soil and dust 

• Incidental ingestion of lagoon and ocean water; see note below 

• Ingestion of drinking water; see note below 

• Ingestion of local food 

• Absorption of radionuclides through puncture wounds or cuts. 

Note: For the pathways of incidental ingestion of lagoon and ocean water, 

and ingestion of drinking water, maximized doses have been estimated to be 

orders of magnitude below 1 mrem using conservative assumptions. 

Therefore, doses from these sources and pathways are subsumed within 

applied upper-bound dose uncertainties with no need to estimate them 

separately. (DTRA, 2020a) 

Using the applicable exposure pathway description and other dose parameter values 

reported in Section 7 of DTRA (2020a), the RDA Analyst calculates 50-year committed 

equivalent doses (CED) for each internal or surrogate organ separately for alpha particles, 

and for beta particles plus gamma rays for each pathway. The alpha dose equals the total 

organ dose from all alpha-emitting radionuclides considered for each pathway, and the 

beta+gamma dose equals the total dose from all other radionuclides included in the dose 

assessment also for each pathway. The RDA Analyst then estimates each organ’s total 
 

 

 

 

 

 

 

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alpha and beta+gamma doses from all pathways and determines upper-bound doses using 

the methods described in DTRA (2020a). 

Default dose parameter input values reported in DTRA (2020a) are compiled in 

Attachment 1 and should be used in the internal dose calculations in the absence of 

veteran-specific exposure information and data. The default input values compiled in 

Attachment 1 are based on information documented and extracted from ECUP historical 

reports and other documentation. Additional details on assumptions and high-sided 

parameter values can be found in DTRA (2020a). 

For exposure scenarios with no available calculation tools specific to ECUP, RDA 

analysts must develop the necessary worksheets for the relevant dose assessment to 

include calculation of total and upper-bound doses using the methods presented in DTRA 

(2020a). 

5.7 Assess Doses to the Skin 

Using information in the veteran’s case file and relevant DTRA guidance, the RDA 

Analyst identifies the applicable reference body location(s) for skin cancer(s) claimed by 

the veteran and requested by the VA. If necessary, standard surrogate skin sites are 

identified. 

Using the review of the veteran’s case file combined with information and guidance 

contained in DTRA (2020a), the RDA Analyst determines potential exposure to ground, 

suspended, or waterborne sources of alpha, beta, and gamma radiation during the 

veteran’s participation in ECUP. Exposures from these sources are assumed to be 

concurrent with exposures to external gamma radiation addressed in Section 5.5 above. 

The following sources of external exposure to the skin are considered for skin dose 

assessments: 

• Direct (non-contact) exposure from residual beta and gamma activity in soil or other 

contaminated material 

• Dermal contamination due to radioactive material in suspended soil deposited on the 

skin or clothing. 

Using applicable calculation tools, the RDA Analyst calculates the veteran-specific beta 

dose and the total beta+gamma dose from non-contact exposure for each identified skin 

location. Where applicable, scenario parameter values should be consistent with 

assumptions used for the veteran’s external dose assessment. In the absence of detailed 

information from the veteran or other appropriate sources, the veteran is assumed to be 

standing during his skin exposures. 

The RDA Analyst uses applicable calculation tools to estimate the alpha and 

beta+gamma doses from dermal contamination for each affected skin location using the 

methods and dose parameter values contained in DTRA (2020a). Default dose parameter 
 

 

 

 

 

 

 

 

 

 

 

 

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values reported in DTRA (2020a) are compiled in Attachment 1 and should be used in 

the skin dose calculations in the absence of veteran-specific exposure information and 

data. Parameter values for factors such as length of a workday and resuspension factors 

should be consistent with assumptions used for the veteran’s external and internal dose 

assessments. 

The doses from all exposure pathways are combined to determine skin dose from alpha 

and beta+gamma radiation for each affected skin location. Total upper-bound doses are 

calculated using the methods and uncertainty factors provided in DTRA (2020a). 

When applicable calculation tools are not available for a specific ECUP scenario, RDA 

analysts must develop the necessary worksheet(s) for the relevant skin dose assessment. 

Newly developed worksheets must include calculation of total and upper-bound skin 

doses using the methods presented in DTRA (2020a). 

5.8 Prepare Internal Draft RDA Report 

The RDA Analyst drafts an RDA Report that contains all dose results and pertinent 

scenario information and assumptions. A detailed description of the content of RDA 

Reports and a standardized template is included as Attachment 2. 

All doses reported in the summary table and dose results tables in the RDA Report are 

listed with two significant figures obtained by rounding up the third figure. For doses 

equal to 0.9 to 9 mrem, results are reported by rounding up the calculated dose to one 

significant figure. In addition, rounded doses less than 0.001 rem are reported as 

“<0.001 rem” when provided in tables and as “less than 1 mrem” or “less than 

0.001 rem” when reported in the text. 

For cases where skin doses are assessed, these should be reported separately by radiation 

type as a dose from alpha radiation and a dose from beta+gamma radiation. 

If a veteran’s assignment spans two calendar years, the sum of the doses is assigned to 

the first year of exposure for both internal organ and skin doses. 

5.9 Perform Reviews 

The RDA Analyst submits the draft RDA Report and associated dose calculations for 

technical review by another RDA Analyst. Particularly, newly developed calculation 

worksheets require a full review cycle, whereas existing worksheets that are applied for a 

veteran’s RDA should be reviewed primarily for accuracy of veteran-specific input and 

transcription of results in the RDA Report. Once the review is completed, the authoring 

RDA Analyst revises the draft RDA Report and dose calculations to address comments 

from the reviewer and then resubmits the revised draft RDA Report and dose calculations 

for final review by the same or another RDA Analyst. 

The reviewers document comments and suggested revisions on the draft documents and 

include their initials in the filename of the reviewed copy. The reviewed copy is saved in 

the veteran folder for the case. Each reviewer completes the Technical Review Checklist 
 

 

 

 

 

 

 

 

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for Radiation Dose Assessments for Participants in the Enewetak Cleanup Project 

provided in Attachment 3. 

Once comments from technical reviews are addressed and incorporated in the draft RDA 

Report, the RDA Analyst forwards the revised draft RDA Report for management 

review. 

The RDA Analyst records the date of the completion of each review on the NTPR RDA 

Internal Tracking and Quality Assurance Checklist included in NTPR SOP RA04. 

5.10 Prepare Final Draft RDA Report 

The RDA Analyst revises the draft RDA Report and dose calculations to address 

comments from the Management Review, prepares a Final Draft RDA Report, and 

assembles all relevant information for transmittal to the DTRA PM. 

5.11 Transmit RDA Report 

Once the Final Draft RDA Report is completed, staff from the RDA team performs the 

following tasks: 

• Prepare an official electronic version (portable document format [pdf] or an approved 

equivalent format) of the Final Draft RDA Report and supporting dose calculation 

worksheet(s) for transmittal to DTRA 

• Transmit the Final Draft RDA Report and worksheet(s) to the DTRA PM or designee 

for final review. 

5.12 Receive DTRA PM Review Comments 

The RDA Analyst evaluates and resolves DTRA PM comments, if any, and prepares a 

revised Final Draft RDA Report and dose calculation worksheets that incorporate DTRA 

PM comments. If no DTRA PM comments are received, the Final Draft RDA Report is 

considered final. 

5.13 Transmit Revised Final Draft RDA Report 

Once the Final Draft RDA Report is completed, the RDA Analyst or other designated 

personnel perform the following tasks: 

• Prepare an official electronic version (portable document format [pdf] or equivalent 

approved format) of the RDA Report and supporting dose calculation worksheet(s), if 

any changes were required during the revision process 

• Complete transmittal of documents to the DTRA PM. The transmitted version is filed 

in the applicable case archive folder. 
 

 

 

 

 

 

 

 

 

 

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6. Data and Records Management 

This SOP is used to produce RDA Reports and dose calculation worksheets for 

individualized veteran dose assessments. Drafts and final electronic versions of these 

dose assessment documents are filed by the RDA Analyst in an individual veteran RDA 

folder on a dedicated storage device. In addition, copies of the veteran’s case file, 

associated data tables, reference material relevant to the case, etc., are placed in the 

veteran’s folder. Electronic copies of all files used or cited in the assessment are stored 

electronically under the same veteran RDA folder. 

Official copies of the final veteran ECUP RDA Report, dose calculation worksheets, and 

supporting information are transmitted to DTRA PM who maintains these files in 

accordance with the NTPR Program Support and Management SOP (DTRA, 2020b). 

7. Quality Assurance and Quality Control 

The NTPR Quality Assurance SOP (DTRA, 2021) describes the quality procedures for 

controlling the NTPR processes and products to ensure that defensible, consistent, and 

objective case processing is accomplished. In addition, NTPR Program Support SOPs 

and RDA SOPs have been written to ensure that QA requirements will be met, by 

documenting the procedures for all aspects of the program, including records research, 

case processing, dose assessments, and report formats. Finally, NTPR Standard Methods 

describe methods, conservative default assumptions, and parameter values to further 

ensure consistency and defensibility of all RDAs. 

Internal quality control checks are performed throughout the RDA development process. 

The RDA Analyst discusses with members of the RDA team proposed assumptions to 

perform the dose assessment until a consensus on best approach to proceed is reached. 

Reviews of draft RDA Reports and dose calculation worksheets are conducted by peer 

analysts from the RDA team as described in Sections 5.4 and 5.9. Management reviews 

provide further assurance that RDAs are prepared consistently and in accordance with 

established policies, guidelines, and procedures. 

Further quality control actions are conducted by independent external reviewers 

according to the NTPR Quality Assurance SOP (DTRA, 2021). Regarding this procedure, 

external reviews are defined as reviews conducted by qualified analysts who are not part 

of the RDA team. RDA Reports and calculation worksheets are revised in response to 

significant comments from such external reviews. Significant comments are those that 

impact major elements of information provided in the RDA Report, such as those that 

could materially affect the dose results in a manner that is not already accounted for 

within the bounds of the uncertainty calculations. An RDA Report that requires revision 

after external reviews is revised, reviewed, and transmitted to DTRA as described above 

in Section 5. 
 

 

 

 

 

 

 

 

 

 

 

 

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8. Referenced SOPs from the NTPR/RDA SOP Manual 

(1) SOP RA04 Internal RDA Reviews 

(2) SOP RA07 Expedited Processing of Radiation Dose Assignments for Enewetak 

Cleanup Project Veterans 

9. References 

AEC (United States Atomic Energy Commission, Nevada Operations Office), 1973. Enewetak 

Radiological Survey, Vol I. NVO-140, United States Atomic Energy Commission, 

Nevada Operations Office, Las Vegas, NV. October. 

Apostoaei, A. and Kocher, D. 2010. Radiation Doses to Skin from Dermal Contamination. 

DTRA TR-09-016, Defense Threat Reduction Agency, Fort Belvoir, VA. October 28. 

Cross, W.G., Freedman, N.O., and Wong, P.Y., 1992. “Beta Ray Dose Distributions from Skin 

Contamination,” Radiation Protection Dosimetry, 40(3): 149–168. 

DNA (Defense Nuclear Agency), 1981. The Radiological Cleanup of Enewetak Atoll. Defense 

Nuclear Agency, Washington, D.C. 

DoD (Department of Defense), 2020. Guidance for the Determination and Reporting of Nuclear 

Radiation Dose for DoD Participants in the Atmospheric Nuclear Test Program 

(1945-1962). Title 32, Code of Federal Regulations, Part 218. Washington, D.C. July 1. 

DTRA (Defense Threat Reduction Agency), 2020a. Radiation Dose Assessment for Military 

Personnel of the Enewetak Atoll Cleanup Project (1977-1980), Revision 1. 

DTRA-TR-17-003(R1). Defense Threat Reduction Agency, Fort Belvoir, VA, April 30. 

DTRA (Defense Threat Reduction Agency), 2020b. DTRA NTPR Program Support and 

Management SOP (Rev. 6). Defense Threat Reduction Agency, Fort Belvoir, VA. 

October 30. 

DTRA (Defense Threat Reduction Agency), 2020c. DTRA NTPR Program Veteran Assistance 

SOP (Rev. 5). Defense Threat Reduction Agency, Fort Belvoir, VA. November 30. 

DTRA (Defense Threat Reduction Agency), 2021. DTRA NTPR Program Quality Assurance 

SOP (Rev. 5). Defense Threat Reduction Agency, Fort Belvoir, VA. February 26. 

ICRP (International Commission on Radiological Protection), 2011. ICRP Database of Dose 

Coefficients: Workers and Members of the Public, Version 3.0. The International 

Commission on Radiological Protection. 

NCRP (National Council on Radiation Protection and Measurements), 2009. Radiation Dose 

Reconstruction: Principles and Practices. Report No. 163, Bethesda, MD. November 13. 

VA (Department of Veterans Affairs), 2020. Reasonable Doubt. Title 38, Code of Federal 

Regulations, Part 3.102. July 1. 
 

 

 

 

 

 

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Attachment 1. 

Default Dose Parameter Values to Use in Radiation 

Dose Assessments for ECUP Participants 

The default values of input parameters used in RDAs for ECUP participants are provided in 

Table A1-1 to Table A1-5 for external doses, Table A1-6 to Table A1-11 for internal doses, and 

Table A1-12 to Table A1-16 for skin doses. The parameter values included in these tables are 

default numbers that are applicable in most cases. They should be replaced with veteran-specific 

values when available. Most of these default parameter values are described in DTRA (2020a) 

and are based on historical documents and technical basis documents, as well as ECUP veteran 

recollections. The environmental characterization data and recommended/default dose input 

parameter values included in this attachment are extracted from DTRA (2020a). 
 

 

 

 

 

 

 

 

 

 

 

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Table A1-1. General default parameter values for external dose assessments 

for ECUP participants 

Parameter Value Rationale/Reference/Comment 

Duration of duty 

tour 

Variable 

(default = 6 months [26 wk]) 

Based on individual’s arrival 

and departure records. Default is 

used only if arrival and 

departure records are not 

available. 

Work schedule 10 h d−1 for 6 d wk−1 This is the default assumption 

for all participants. 

External exposure 

rate on residence 

and work island 

Island-specific or 

multi-island average 

(See Table A1-2) 

See Table A1-3 for guidance 

when multiple islands are 

involved. For debris cleanup on 

multiple islands, use debris data 

in Table A1-4 for averaging. 

Time spent outdoors 

and indoors on 

residence island 

See Table A1-5 

Protection factor Tent: 1.5 

Building: 2.0 

Film badge 

conversion factor 

(for 3 orientations 

relative to a source) 

Facing source: 1.0 rem R−1

Standing upright: 0.7 rem R−1

Facing away: 0.5 rem R−1

Fraction of workday 

exposed to source 

0.1 to 1 

(default = 1) 

Fraction of a workday or of 

work duration that a worker is 

exposed to a radiation source. 
 

 

 

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Table A1-2. External exposure rates and surface soil activity concentrations for all islands 

Island Name Site Name 

Average 

Exposure Rate 

(μR h−1 at 1 m)* 

Mean Island-average Soil Concentrations in top 15 cm (pCi g−1) 

Co-60 Sr-90 Cs-137 Pu-239/240 Am-241 

Northern Islands 

Bokoluo Alice 81 5.9 107.9 44.1 15.6 10.4 

Bokombako Belle 115 10 148.9 47.5 27.1 18.1 

Kirunu Clara 42 6.4 99.2 35.4 31.6 21.1 

Louj Daisy 21.3 11 107.7 10.5 31.6 21.1 

Bocinwotme Edna 6 0.43 68.6 4.7 19.4 12.9 

Boken Irene 80 5.4 52.8 7.3 26.2 5.2 

Enjebi Janet 40 1.9 72.9 27.0 16.2 3.2 

Mijikadrek Kate 19 2.7 43.5 13.1 11.3 7.5 

Kidrinen Lucy 14 1.5 30.1 10.3 7.7 5.1 

Taiwel Percy 5 0.47 34.6 7.3 9.0 6.0 

Bokenelab Mary 10 1.5 34.8 8.4 10.1 6.7 

Elle Nancy 12 1.6 39.3 11.6 10.1 6.7 

Aej Olive 11 1.5 21.5 7.7 8.4 5.6 

Lujor Pearl 70 12 28.3 12.4 38.3 7.7 

Eleleron Ruby 14 0.93 24.3 3.2 14.5 9.7 

Aomon Sally 7 0.54 16 5.7 11.0 2.2 

Bijire Tilda 6 1.2 19.1 4.2 6.5 4.3 

Lojwa Ursula 5 0.31 8.2 2.6 1.8 1.2 

Alembel Vera 5 0.3 12.5 4.4 4.3 2.9 

Billae Wilma 2 0.12 6.0 2.0 1.8 1.2 

Runit Yvonne 33 0.64 3.3 1.00 8.7 1.7 
 

 

 

 

 

 

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Table A1-2. External exposure rates and surface soil activity concentrations for all islands (cont.) 

Island Name Site Name 

Average 

Exposure Rate 

(μR h−1 at 1 m)* 

Mean Island-average Soil Concentrations in top 15 cm (pCi g−1) 

Co-60 Sr-90 Cs-137 Pu-239/240 Am-241 

Southern Islands 

Boko Sam† 0.31 0.04 0.72 0.38 0.09 0.06 

Munjor Tom† 0.31 0.04 0.72 0.32 0.08 0.05 

Inedral Uriah† 0.49 0.15 0.45 0.11 0.08 0.05 

n/a Van† 0.33 0.09 0.41 0.14 0.08 0.05 

Jinedrol Alvin† 0.31 0.68 0.44 0.11 0.06 0.04 

Ananij Bruce 1.2 0.12 0.59 0.40 0.09 0.06 

Jinimi Clyde† 0.15 0.04 0.23 0.06 0.06 0.04 

Japtan David† 0.31 0.03 0.55 0.40 0.05 0.03 

Jedrol Rex† 0.53 0.09 0.51 0.51 0.04 0.03 

Medren (Parry) Elmer† 0.31 0.06 0.76 0.32 0.21 0.14 

Bokandretok Walt† 0.18 0.04 0.41 0.15 0.04 0.03 

Enewetak Fred† 0.26 0.04 0.61 0.25 0.08 0.05 

Ikuren Glenn† 0.53 0.21 1.37 0.60 0.11 0.07 

Mut Henry† 0.34 4.3 0.75 0.25 0.14 0.09 

Boken Irwin† 0.54 0.62 0.69 0.13 0.13 0.09 

Ribewon James 3 6.5 0.69 0.08 0.08 0.05 

Kidrenen Keith† 0.64 0.17 0.88 0.28 0.11 0.07 

Biken Leroy 7.6 0.58 16.8 5.06 1.15 0.77 

* Converted from 1972 aerial survey results for each island (DTRA, 2020a). 

† Exposure rates on these islands are lower than the limit of sensitivity of the aerial survey equipment; for these, exposure rates are derived from soil sample 

activity concentration data (AEC, 1973). 
 

 

 

 

 

 

 

 

 

 

 

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Table A1-3. Averaging methods to determine exposure rates or soil activity 

concentrations for scenarios where ECUP veterans worked on multiple islands 

Type of Work 

If work islands are known 

If work islands are 

not known 

Durations on specific 

islands are known 

Durations on specific 

islands are not 

known 

Work involving or 

supporting soilremoval activities* 

TWA† using values 

for known soilremoval islands 

VWA‡ using values 

for known soilremoval islands 

VWA using values for 

all soil-removal 

islands 

General work only 

on northern 

islands§,** 

TWA using values for 

known northern 

islands 

SA†† using values for 

known northern 

islands 

SA using values for all 

northern islands 

General work only 

on southern islands 

TWA using values for 

known southern 

islands 

SA using values for 

known southern 

islands 

SA using values for all 

southern islands 

General work on 

northern and 

southern islands 

TWA using values for 

known northern and 

southern islands 

SA using values for 

known northern and 

southern islands 

SA using values for all 

northern islands

‡‡ 

* Soil-removal islands and the volume of contaminated soil removed from each of the five soil-removal islands 

are shown in Table A1-7. 

† TWA = Time-weighted average of values, e.g., exposure rates or soil activity concentrations. Time-weighted 

averages are based on the amount of time spent on each identified island. 

‡ VWA = Volume-weighted average of values, e.g., exposure rates or soil activity concentrations. Volumeweighted averages are based on the volume of soil or debris removed from each identified island. 

§ Northern and southern islands are identified in Table A1-2. 

** “General work” can be any work other than participation in direct soil-removal or debris-removal work, such as 

sampling, monitoring, and surveying. 

†† SA = Simple average (arithmetic mean) of values. 

‡‡ Using SA for all northern islands for this scenario will likely result in a high-sided average exposure rate or soil 

activity concentration. 
 

 

 

 

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Table A1-4. ECUP participant debris cleanup volumes at Enewetak Atoll 

Island Name * Site Name 

Total volume of debris†,‡,§ 

(yd3) 

Northern Islands 

Bokoluo Alice 1,575 

Bokombako Belle 28 

Kirunu Clara 505 

Louj Daisy 5 

Bokaidrik Helen 15 

Boken Irene 1,890 

Enjebi Janet 16,477** 

Mijikadrek Kate 1,073 

Kidrinen Lucy 257 

Taiwel Percy 2 

Bokenelab Mary 158 

Elle Nancy <1 

Aej Olive 1 

Lujor Pearl 271** 

Eleleron Ruby 251** 

Aomon Sally 2,914** 

Bijire Tilda 720 

Lojwa Ursula 2,115 

Alembel Vera <1 

Billae Wilma 64 

Runit Yvonne 15,602** 

Southern Islands 

Ananij Bruce 95 

Japtan David 790†† 

Jedrol Rex 28 

Medren (aka Parry) Elmer 41,028†† 

Enewetak Fred 110,780†† 

Ikuren Glenn 908 

Mut Henry 215 

Boken Irwin 270 

Ribewon James 254 

Kidrenen Keith 140 

Biken Leroy 197 
 

 

 

 

 

 

 

 

 

 

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Table A1-4. ECUP participant debris cleanup volumes at Enewetak Atoll (cont.) 

N/A (no native name) Van 10 

Bokandretok Walt 10 

Total 198,650 * Nine islands that had no debris removed are not included in this table. 

† Debris volumes are from DTRA (2020a). 

‡ The debris volumes in this table include debris used as shore protection. 

§ Volumes in this table are volumes of uncontaminated debris unless indicated otherwise. 

** The total volumes for these five islands include the following volumes of contaminated debris: 

Enjebi (530 yd3

), Lujor (255 yd3), Eleleron (250 yd3), Aomon (728 yd3), Runit (4,120 yd3). 

†† A total of 55,000 yd3 of debris were removed from these three islands by a scrap contractor (DNA, 

1981). The volumes removed by the scrap contractor are excluded from the values in this table. 
 

 

 

 

 

 

 

 

 

 

 

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Table A1-5. Time spent outdoors and indoors on residence islands 

Work Location, Day of 

Week, and Worker 

Category 

Daily Duration (h d−1) 

Rationale/Reference/Comment Outdoor Indoor* 

Enewetak and Lojwa Support Workers† 

Workdays (6 d wk−1): 

Outdoor Workers 15 9 

Outdoor time is working and 

recreation; indoor time is sleeping 

and eating. 

Indoor Workers 5 19 Outdoor time is recreation; indoor 

time is sleeping, eating, and working. 

Non-Workdays (1 d wk−1): 

Outdoor and Indoor 

Workers 15 9 Outdoor time is recreation; indoor time is sleeping and eating. 

Northern Island Workers (Lojwa Island)‡ 

and Southern Island Workers (Enewetak Island)§ 

Workdays (6 d wk−1) 5 9 Outdoor time is recreation; indoor 

time is sleeping and eating. 

Non-Workdays (1 d wk−1) 15 9 Outdoor time is recreation; indoor 

time is sleeping and eating. * On all days, sleeping and eating indoors are assumed to take 8 h and 1 h, respectively (DTRA, 2020a). 

† Participants normally assigned to work locations on Enewetak Island or Lojwa Island with billeting on the same 

island. 

‡ Northern-Island Workers are those participants who were billeted on Lojwa Island but were normally assigned 

to work locations on other northern islands. These workers may have also occasionally conducted work on Lojwa 

Island. 

§ Southern Island Workers are those participants who were billeted on Enewetak Island but were normally 

assigned to work locations on other southern islands. These workers may have also occasionally conducted work 

on Enewetak Island. 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

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Table A1-6. General default parameter values for internal dose assessments 

for ECUP participants 

Parameter Value Rationale/Reference/ 

Comment 

Duration of duty tour Variable 

(default = 6 months) 

Default is used only if arrival 

and departure records are not

available. 

Work schedule 10 h d−1 for 6 d wk−1 This is the default assumption

for all participants. 

Activity concentrations of 

undisturbed soil 

Island-specific or 

multi-island average 

(See Table A1-2) 

See Table A1-3 for guidance if

multiple islands are involved. 

Activity concentrations of excised 

soil 

Island-specific 

(See Table A1-7) 

Based on total TRU activities 

and total soil volumes removed. 

Average daily time outdoors 

• Outdoor workers: 

• Indoor workers 

− Workdays: 

− Non-workdays: 

15 h d−1 for 7 d wk−1 

5 h d−1 for 6 d wk−1 

15 h d−1 for 1 d wk−1 

All non-work time other than 

sleeping and eating is

recreational time spent outdoors 

on residence island. See also 

Table A1-5. 

Resuspension factor (RF) and soil 

mass loading (ML): 

– Ambient dust loading 

– Generic default 

– Vehicle/truck traffic 

– Soil pile work 

– Clearing vegetation 

– Soil excision and 

windrowing 

RF (m−1) 

810−9 

210−8 

210−8 

510−8 

610−8 

1.210−7 

−3 ML (μg m )

40 

100 

100 

250 

300 

600 

The numerical relationship

between RF and ML is based on 

the values for “depth of

suspended soil,” “soil density,”

and “enhancement factor” 

shown below. 

Depth of suspended soil 1 cm 

Soil density 1.5 g cm−3 

Enhancement factor 3 

Breathing rate 1.2 m3 h−1 

Respiratory protection factor See Table A1-8 

Inhalation and ingestion dose 

coefficients See Table A1-9 and Table A1-10 

Fraction of time exposed to 

source (inhalation) 1.0 

Incidental soil ingestion rate 0.05 g d−1 

Frequency and type of local food 

consumption 

Veteran-specific 

(Default = 1 serving per week)* 

(Default food = Fish)

† 

Include this pathway only if 

stated by the veteran. 

Internal dose per serving from 

local food consumption See Table A1-11 

* Default frequency should be used if a frequency is not specified by the veteran, e.g., in his ECUP Questionnaire. 

This default frequency is considered a high-sided average per ECUP veteran’s anecdotes (DTRA, 2020a). 

† When not specified by the veteran, fish should be selected as the default food because it was the most commonly 

available local food that personnel may have consumed. 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

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Table A1-7. Estimated activity concentration of contaminated soil excised 

and moved to Cactus crater and dome 

Island with 

Contaminated Soil 

Total TRU 

Activity 

(Ci)* 

Soil Volume Removed (yd3)

* Average TRU 

Activity 

Concentration 

†

(pCi g−1 Crater Dome )

Total 

volume 

Medren 0 110 0 110 0‡ 

Aomon 1.29 10,603 0 10,603 106 

Aomon Crypt 0.93 448 9,328 9,776 83 

Boken 1.01 421 4,516 4,937 178 

Enjebi 2.57 43,023 9,984 53,007 42 

Lujor 1.70 0 14,929 14,929 99 

Runit 7.22 0 10,735 10,735 587 

Overall totals 

(Runit not included) 7.50 54,605 38,757 93,362 70§ 

Overall Totals 

(Runit included) 14.72 54,605 49,492 104,097 123§ 

* Total TRU activity values and soil volumes are from DNA (1981). 

† Soil activity concentrations are based on an average bulk soil density of 1.5 g cm−3 (DTRA, 2020a). 

‡ The 110 cubic yards of soil removed from Medren was contaminated only with Co-60, with hotspots ranging 

between 20–2000 pCi g−1

. Based on soil volumes removed and their maximum concentrations, the average 

Co-60 activity concentration in this soil is estimated to be less than 170 pCi g−1

. (DTRA, 2020a) 

§ These average TRU soil activity concentrations are weighted averages calculated using total soil volume 

removed from each island. 

Table A1-8. ECUP personnel protection levels and respiratory protection factors 

ECUP Personnel 

Protection Level ECUP Respiratory Protection* 

Respiratory 

Protection Factor† 

I or II-A None 1 

II-B Surgical mask (dust mask) 1 

III-A or III-B 

Full-face negative pressure respirator 50 

Half-face positive pressure respirator 50 

Full-face positive pressure respirator 1,000 

IV Full-face positive pressure respirator 1,000 

* Half-face, negative pressure respirators (protection factor of 10) are mentioned in some ECUP documentation 

(e.g., FCCR SOP 608-10 “Decontamination Laundry Procedures.” However, this respirator type is not listed in 

the ECUP “Personnel Protection Levels” documentation (EAI No. 5707.1). (DNA, 1981; DTRA, 2020a) 

† For use in ECUP dose assessments, the respiratory protection factor for work in controlled access areas can 

normally be determined from the Personnel Protection Level specified in relevant Controlled Island Access 

forms. When Level III-A or III-B is indicated in the Controlled Island Access form, a respiratory protection factor 

of 50 should be used unless it is known that a full-face, positive pressure respirator was worn. 
 

 

 

 

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Table A1-9. Inhalation dose coefficients for use in internal dose assessments for ECUP participants 

Organ/Tissue† 

Inhalation Dose Coefficients* (rem pCi−1) 

Co-60 Sr-90 Sb-125 Cs-137 Eu-155 Pu-239 Am-241 

Adrenals 2.4110−8 2.2210−9 4.0710−9 1.8110−8 6.6610−9 9.2510−6 9.9910−6 

Bladder Wall 8.8810−9 4.8110−9 1.1510−9 1.8510−8 7.0310−10 9.2510−6 9.9910−6 

Bone Surface 1.3710−8 1.3710−6 3.0310−8 1.7810−8 4.0710−7 5.5510−3 5.9210−3 

Brain 7.0310−9 2.2210−9 9.9910−10 1.5210−8 9.9910−10 9.2510−6 9.9910−6 

Breast 2.1510−8 2.2210−9 3.5510−9 1.4410−8 1.4810−9 9.2510−6 9.9910−6 

Esophagus 2.5210−8 2.2210−9 4.0710−9 1.6710−8 1.7410−9 9.2510−6 9.9910−6 

St Wall 1.5910−8 2.2910−9 2.4110−9 1.7010−8 2.2610−9 9.2510−6 9.9910−6 

SI Wall 1.2210−8 2.4110−9 1.9210−9 1.8110−8 2.4410−9 9.2510−6 9.9910−6 

ULI Wall 1.4410−8 7.0310−9 3.6610−9 1.8510−8 4.0710−9 9.2510−6 9.9910−6 

LLI Wall 1.8110−8 1.9210−8 7.4010−9 2.1510−8 4.8110−9 9.2510−6 9.9910−6 

Colon 1.5910−8 1.2210−8 5.1810−9 1.9610−8 4.4410−9 9.2510−6 9.9910−6 

Kidneys 1.4110−8 2.2210−9 1.9210−9 1.7410−8 4.8110−9 2.1810−5 3.0010−5 

Liver 3.0010−8 2.2210−9 4.8110−9 1.7410−8 1.3010−7 1.1110−3 3.5910−4 

Muscle 1.3310−8 2.2210−9 2.0710−9 1.6310−8 1.7010−9 9.2510−6 9.9910−6 

Ovaries 1.1510−8 2.2210−9 1.6710−9 1.8510−8 1.7010−9 7.0310−5 1.1510−4 

Pancreas 2.0010−8 2.2210−9 3.0710−9 1.8510−8 5.1810−9 9.2510−6 9.9910−6 

Red Marrow 1.5210−8 5.9210−7 5.9210−9 1.6710−8 3.6310−8 2.5910−4 2.0410−4 

ET Airways 6.2910−8 6.6610−9 2.3310−8 2.8910−8 1.2210−8 3.5210−5 3.6610−5 

Lungs 1.8110−7 2.2910−9 1.1110−7 1.6310−8 6.2910−8 1.1110−4 1.2610−4 
 

 

 

 

 

 

 

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Table A1-9. Inhalation dose coefficients for use in internal dose assessments for ECUP participants (cont.) 

Organ/Tissue† 

Inhalation Dose Coefficients* (rem pCi−1) 

Co-60 Sr-90 Sb-125 Cs-137 Eu-155 Pu-239 Am-241 

Skin 8.5110−9 2.2210−9 1.2210−9 1.3710−8 8.1410−10 9.2510−6 9.9910−6 

Spleen 1.8510−8 2.2210−9 2.8110−9 1.7410−8 1.5910−9 9.2510−6 9.9910−6 

Testes 7.0310−9 2.2210−9 7.4010−10 1.6310−8 2.9610−10 7.0310−5 1.1510−4 

Thymus 2.5210−8 2.2210−9 4.0710−9 1.6710−8 1.7410−9 9.2510−6 9.9910−6 

Thyroid 1.3310−8 2.2210−9 1.8910−9 1.6710−8 9.2510−10 9.2510−6 9.9910−6 

Uterus 9.9910−9 2.2210−9 1.2610−9 1.8510−8 1.1810−9 9.2510−6 9.9910−6 

Effective dose 3.5510−8 8.8810−8 1.6710−8 1.7810−8 2.4110−8 1.7410−4 1.4410−4 

* Dose coefficients obtained from ICRP 68 (ICRP, 2011). 

† Abbreviations used in this table: SI Wall = Small Intestine Wall; ULI Wall = Upper Large Intestine Wall; LLI Wall = Lower Large Intestine Wall; 

ET Airways = Extra-thoracic Airways. 
 

 

 

 

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Table A1-10. Ingestion dose coefficients for use in internal dose assessments for ECUP participants 

Organ/Tissue† 

Ingestion Dose Coefficients* (rem pCi−1) 

Co-60 Sr-90 Sb-125 Cs-137 Eu-155 Pu-239 Am-241 

Adrenals 9.2510−9 2.4410−9 1.5510−9 5.1810−8 4.8110−11 5.1810−8 5.5510−8 

Bladder Wall 9.6210−9 5.5510−9 1.5910−9 5.1810−8 1.1110−10 5.1810−8 5.5510−8 

Bone Surface 7.4010−9 1.5210−6 3.3310−8 5.1810−8 2.4410−9 3.0310−5 3.3310−5 

Brain 5.1810−9 2.4410−9 9.6210−10 4.4410−8 5.5510−12 5.1810−8 5.5510−8 

Breast 4.8110−9 2.4410−9 7.7710−10 4.0710−8 7.0310−12 5.1810−8 5.5510−8 

Esophagus 6.2910−9 2.4410−9 9.2510−10 4.8110−8 7.4010−12 5.1810−8 5.5510−8 

St Wall 9.2510−9 3.3310−9 1.8110−9 4.8110−8 3.6610−10 5.5510−8 5.9210−8 

SI Wall 1.5510−8 4.0710−9 3.5910−9 5.1810−8 9.9910−10 6.2910−8 6.6610−8 

ULI Wall 2.4110−8 2.1510−8 9.2510−9 5.1810−8 4.4410−9 1.1810−7 1.3010−7 

LLI Wall 4.4410−8 8.1410−8 2.2910−8 6.2910−8 1.3010−8 2.4810−7 2.7410−7 

Colon 3.2210−8 4.8110−8 1.5210−8 5.5510−8 8.1410−9 1.7410−7 1.9210−7 

Kidneys 8.8810−9 2.4410−9 1.4110−9 4.8110−8 6.2910−11 1.2210−7 1.7010−7 

Liver 1.6310−8 2.4410−9 2.8910−9 4.8110−8 7.7710−10 6.2910−6 2.0010−6 

Muscle 7.0310−9 2.4410−9 1.1510−9 4.4410−8 4.4410−11 5.1810−8 5.5510−8 

Ovaries 1.5910−8 2.4410−9 2.9210−9 5.1810−8 3.5210−10 4.0710−7 6.2910−7 

Pancreas 9.6210−9 2.4410−9 1.4110−9 5.1810−8 6.2910−11 5.1810−8 5.5510−8 

Red Marrow 7.7710−9 6.6610−7 5.5510−9 4.8110−8 2.5910−10 1.4410−6 1.1510−6 

ET Airways 6.2910−9 2.4410−9 9.6210−10 4.8110−8 4.4410−12 5.1810−8 5.5510−8 

Lungs 6.6610−9 2.4410−9 1.0710−9 4.8110−8 2.0410−11 5.1810−8 5.5510−8 
 

 

 

 

 

 

 

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Table A1-10. Ingestion dose coefficients for use in internal dose assessments for ECUP participants (cont.) 

Organ/Tissue† 

Ingestion Dose Coefficients* (rem pCi−1) 

Co-60 Sr-90 Sb-125 Cs-137 Eu-155 Pu-239 Am-241 

Skin 4.8110−9 2.4410−9 7.7710−10 4.0710−8 1.3010−11 5.1810−8 5.5510−8 

Spleen 7.7710−9 2.4410−9 1.1110−9 4.8110−8 3.4010−11 5.1810−8 5.5510−8 

Testes 6.6610−9 2.4410−9 9.2510−10 4.4410−8 2.5510−11 4.0710−7 6.2910−7 

Thymus 6.2910−9 2.4410−9 9.2510−10 4.8110−8 7.4010−12 5.1810−8 5.5510−8 

Thyroid 6.2910−9 2.4410−9 9.6210−10 4.8110−8 4.4410−12 5.1810−8 5.5510−8 

Uterus 1.1110−8 2.4410−9 1.8110−9 5.1810−8 1.5910−10 5.1810−8 5.5510−8 

Effective dose 1.2610−8 1.0410−7 4.0710−9 4.8110−8 1.1810−9 9.2510−7 7.4010−7 

* Dose coefficients obtained from ICRP 68 (ICRP, 2011). 

† Abbreviations used in this table: SI Wall = Small Intestine Wall; ULI Wall = Upper Large Intestine Wall; LLI Wall = Lower Large Intestine Wall; 

ET Airways = Extra-thoracic Airways. 
 

 

 

 

 

 

 

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Table A1-11. Organ doses from potential consumption of local food by ECUP participants 

Organ/Tissue† 

Ingestion Doses (rem per serving)

* 

Fish Lobster 

Coconut 

Meat 

Coconut 

Milk 

Coconut 

Crab 

Adrenals 4.9810−6 4.6010−7 7.8610−5 7.3410−5 2.5710−5

Bladder Wall 5.0610−6 4.8010−7 7.9110−5 7.3510−5 2.6110−5

Bone Surface 9.8310−4 2.4910−5 5.0310−4 1.2710−4 1.7210−4

Brain 4.0310−6 3.0810−7 6.7410−5 6.2910−5 2.1910−5

Breast 3.8410−6 2.8810−7 6.1910−5 5.7710−5 2.0110−5

Esophagus 4.3510−6 3.5310−7 7.3010−5 6.8210−5 2.3710−5

Stomach Wall 4.9710−6 4.5710−7 7.3210−5 6.8210−5 2.4110−5

SI Wall 6.4110−6 6.8310−7 7.9110−5 7.3610−5 2.6410−5

ULI Wall 9.7710−6 1.0510−6 8.2410−5 7.4110−5 2.8710−5

LLI Wall 1.8210−5 1.9810−6 1.1010−4 9.1210−5 4.1110−5

Colon 1.3310−5 1.4310−6 9.2810−5 7.9910−5 3.3510−5

Kidneys 7.4010−6 4.8910−7 7.3510−5 6.8310−5 2.4010−5

Liver 1.5810−4 5.0210−6 1.1110−4 7.3910−5 2.5710−5

Muscle 4.3510−6 3.7010−7 6.7510−5 6.2910−5 2.2010−5

Ovaries 1.9310−5 9.3010−6 8.0910−5 7.3910−5 2.6310−5

Pancreas 5.0410−6 4.7210−7 7.8610−5 7.3410−5 2.5810−5

Red Marrow 4.9110−5 2.9010−6 1.8810−4 8.1010−5 8.5610−5

ET Airways 4.3510−6 3.5310−7 7.3010−5 6.8210−5 2.3710−5

Lungs 4.4110−6 3.6510−7 7.3010−5 6.8210−5 2.3810−5

Skin 3.8410−6 2.8810−7 6.1910−5 5.7710−5 2.0110−5

Spleen 4.6010−6 4.0310−7 7.3010−5 6.8210−5 2.3910−5

Testes 1.7410−5 6.0410−7 6.9610−5 6.3310−5 2.2110−5

Thymus 4.3510−6 3.5310−7 7.3010−5 6.8210−5 2.3710−5

Thyroid 4.3510−6 3.5310−7 7.3010−5 6.8210−5 2.3710−5

Uterus 5.2910−6 5.2210−7 7.8710−5 7.3510−5 2.5910−5

Effective dose 3.1310−5 1.4010−6 9.4610−5 7.0810−5 3.3810−5

* Dose calculations are described in DTRA (2020a). 

† Abbreviations used in this table: SI Wall = Small Intestine Wall; ULI Wall = Upper Large Intestine Wall; 

LLI Wall = Lower Large Intestine Wall; ET Airways = Extra-thoracic Airways. 
 

 

 

 

 

 

 

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Table A1-12. General default parameter values for use in non-contact skin dose 

assessments for ECUP participants 

Parameter Default Value Reference/Comment 

Duration of duty tour Variable 

(default = 6 mo [26 wk]) 

Default is used only if arrival and 

departure records are not available. 

Work schedule 10 h d−1 for 6 d wk−1 This is the default assumption for all 

participants. 

Exposure duration Variable 

Calculated using values for “Duration 

of duty tour” and “Work schedule” 

above. 

Fraction of workday 1.0 

(range is 0.1–1) 

Fraction of a workday or work duration 

that a worker is exposed to a radiation 

source. 

Gamma exposure rate 

on island 

Island-specific or 

multi-island average 

(See Table A1-2) 

See Table A1-3 for guidance when 

multiple islands are involved. 

Ratio of beta dose to 

gamma dose See Table A1-13 

Values are applicable to exposure 

above a planar, contaminated source 

(e.g., soil). 

Heights of various skin 

locations See Table A1-14 “Standard” heights are provided in cited table. 

Modification Factor 1 

(range is 0–1) 

The default value assumes bare skin 

and no other modifying factors. 
 

 

 

 

 

 

 

 

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Table A1-13. Beta-to-gamma dose ratios for external non-contact radiation sources 

for all islands at Enewetak Atoll 

Skin Height from Contaminated Ground Surface (cm) 

1 20 40 80 100 120 160 200 

Beta-gamma Dose 

Ratio* 1.2 0.72 0.45 0.34 0.29 0.25 0.18 0.14 

* Beta-gamma dose ratios are from DTRA (2020a). 

Table A1-14. Reference heights of body locations from surface 

Anatomical Location 

Reference Heights for Three Positions* (cm) 

Standing 

Sitting 

(chair/bench) 

Sitting 

(ground/deck) 

Foot and ankle 1.0 1.0 5.1 

Shin 20.3 20.3 15.2 

Knee 40.6 40.6 15.2 

Mid-thigh 71.1 53.1 15.2 

Waist 99.1 56.4 14.0 

Forearms 99.1 56.4 20.3 

Stomach 119 76.7 34.3 

Mid-chest 140 97.0 54.6 

Neck 150 107 64.8 

Face and head/eyes 160 117 74.9 

Top of head 173 130 87.6 * Reference heights are for a veteran stature of 173 cm (68 inches). Skin location heights for 

veterans that are shorter or taller than the reference height can be obtained using a ratio of the 

heights. (DTRA, 2020a) 
 

 

 

 

 

 

 

 

 

 

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Table A1-15. General default parameter values for use in dermal contamination skin dose 

assessments for ECUP participants 

Parameter Default Value Reference/Comment 

Duration of duty tour 

Variable 

(default = 6 months 

[26 wk]) 

Default is used only if arrival and 

departure records are not available. 

Work schedule 10 h d−1 for 6 d wk−1 This is the default assumption 

for all participants. 

Dose coefficients See Table A1-16 

Skin dose modification factor See Table A1-16 For use with beta-emitters 

Daily exposure to dermal 

contamination 12 h d−1 

Value is the daily work hours 

plus an average 2 hours at which 

time removal of contaminated 

soil is assumed. 

Resuspension factor (RF) and soil 

mass loading (ML): 

− Ambient dust loading 

− Generic default 

− Vehicle/truck traffic 

− Soil pile work 

− Clearing vegetation 

− Soil excision and 

windrowing 

RF 

(m−1) 

810−9 

210−8 

210−8 

510−8 

610−8 

1.210−7 

ML 

(μg m−3) 

40 

100 

100 

250 

300 

600 

The numerical relationship 

between RF and ML is based on 

the values for depth of 

suspended soil, soil density, and 

“enhancement factor” given 

below and in Table A1-6. 

Deposition velocity 3600 m h−1 

Interception and retention fraction See Table A1-16 

Fraction of workday exposed 1.0 

(range is 0.1–1) 

Fraction of a workday exposed 

to suspended soil 

Depth of suspended soil 0.01 m 

Soil density 1.5106 g m−3 

Activity concentrations of 

undisturbed soil 

Island-specific or 

multi-island average 

(See Table A1-2) 

See Table A1-3 for guidance if 

multiple islands are involved. 

Activity concentrations of excised 

soil 

Island-specific 

(See Table A1-7) 

Based on total TRU activities 

and total soil volumes removed 

from soil-removal islands. 
 

 

 

 

 

 

 

 

 

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Date: February 15, 2022 

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Table A1-16. Radionuclide-dependent and skin site-dependent default parameter values for use in dermal contamination skin 

dose assessments for ECUP participants 

Skin Site SDMF*,† 

Interception 

and Retention 

Fraction‡ 

Dose Coefficient§ (rem h−1 per pCi cm−2) 

Co-60 Sr/Y-90 Cs-137 Pu-239/240 Am-241 

Scalp 0.3 0.23 

3.830  10−6

(all skin sites) 

1.204  10−5

(all skin sites) 

5.687  10−6

(all skin sites) 

6.40  10−3 7.40  10−3

Face 1.3 0.015 6.40  10−3 7.40  10−3

Forehead 1.3 0.015 6.40  10−3 7.40  10−3

Neck 1.3 0.015 6.40  10−3 7.40  10−3

Shoulder 1.3 0.015 6.40  10−3 7.40  10−3

Chest 1.3 0.03 6.70  10−3 8.20  10−3

Torso (back, side) 1.3 0.015 6.40  10−3 7.40  10−3

Forearm 0.9 0.06 7.40  10−4 1.30  10−3

Upper leg 1.3 0.06 7.40  10−4 1.30  10−3

Lower leg 0.9 0.06 7.40  10−4 1.30  10−3

Palm of hand 0.3 0.015 0 0 

Back of hand 0.3 0.06 0 0 

Sole of feet 0.3 0.015 0 0 

Under belt 1.3 1.5 6.70  10−3 8.20  10−3

Under boot edge 0.9 1.5 7.40  10−4 1.30  10−3

Behind ear 1.3 1.5 6.40  10−3 7.40  10−3

Back of neck 0.9 1.5 6.40  10−3 7.40  10−3

* Skin Dose Modification Factor (SDMF) is applicable only to beta-emitting radionuclides (Co-60, Sr/Y-90, and Cs-137). 

† SDMF values are from Apostoaei and Kocher (2010) 

‡ Interception and retention fractions are from Apostoaei and Kocher (2010) 

§ Dose coefficients are from Cross et al. (1992) and NCRP (2009) 
 

 

 

 

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Attachment 2. 

Template of a Standard RDA Report for Participants 

in the Enewetak Cleanup Project 

A copy of the template for a standard RDA Report for Participants in the Enewetak 

Cleanup Project is provided starting on the next page. All text inserts between brackets 

and in red color should be replaced with case-specific information. 
 

 

 

 

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Date: February 15, 2022 

Page 47 of 49 

Attachment 3. 

Technical Review Checklist for Radiation Dose Assessments 

for Participants in the Enewetak Cleanup Project 

A copy of the “Technical Review Checklist for Radiation Dose Assessments for 

Participants in the Enewetak Cleanup Project” is provided starting on the next page. 
 

 

 

 

DTRA / NTPR - Standard Operating Procedures Manual 

RA06 – Radiation Dose Assessment for Participants in the Enewetak Cleanup Project 

Revision No.: 1.2 

Date: February 15, 2022 

Page 48 of 49 
 

 

 

 

DTRA / NTPR - Standard Operating Procedures Manual 

RA06 – Radiation Dose Assessment for Participants in the Enewetak Cleanup Project 

Revision No.: 1.2 

Date: February 15, 2022 

Page 49 of 49