Closeout of TBD Issues Pertaining to 

the Summary Site Profile for the 

Pacific Proving Grounds (PPG)

James E. Lockey, MD, MS (Chair) 

Henry A. Anderson, MD

R. William Field, PhD, MS

Loretta R. Valerio

Presented to: 

The Advisory Board on Radiation and Worker Health 

Santa Fe, NM, Meeting

August 23–24, 2017
Overview of PPG Activities/Locations

• Between 1946 and 1962, the U.S. Atomic 

Energy Commission conducted a total of 105 

atmospheric and underwater nuclear 

weapons tests at several locations.

• N-Test Locations in Mid-Pacific Ocean

– Bikini Atoll – Marshall Islands

– Enewetak Atoll – Marshall Islands

– Johnston Island

– Christmas Island

– Other Pacific locations

2
Summary Statistics of PPG N-Tests

Location of Test

Number of Weapons 

Detonated

Total Yield 

(megatons TNT)

Continental United States 107 1.38

All PPG Tests 105 151.55

Marshall Islands 66 108.5

• Bikini Atoll 24 76.84

• Enewetak Atoll 42 31.65

Comparison of Nuclear Tests Conducted 

in the U.S. vs. PPG

3

Key N-Test Data Bikini 

Atoll

Enewetak 

Atoll

Christmas 

Island Area

Johnson Atoll 

Area

Other Pacific 

Locations

Time Period 1946–1958 1948–1958 1962 1958–1962 1955; 1962

Number of Tests 24 42 24 12 3

YIELD (Mt TNT equivalent):

Minimum 0.0017 0.0022 0.0022 0.0113 0.030

Maximum 15.000 10.400 7.650 8.300 0.030

Sub-Totals 76.838 31.653 23.253 19.776+ 0.030+
Chronology for the Resolution of the 

PPG Technical Basis Document (TBD)

• August 30, 2006: NIOSH issued ORAUT-TKBS-0052, 

Summary Site Profile for the Pacific Proving Ground

(NIOSH 2006).

• June 2012: SC&A was tasked to conduct a review of 

Revision 00 to the PPG site profile.

• November 5, 2013: SC&A issued Review of the Summary 

Site Profile for the Pacific Proving Grounds (SC&A 2013),

which identified 9 findings and 1 observation.

• May 20, 2014: In response to SC&A’s findings/ 

observation, NIOSH issued an Issues Resolution Matrix 

for Pacific Proving Ground Site Profile (NIOSH 2014).

4
Chronology (cont.)

• January 16, 2015: PPG Work Group (WG) 

teleconference:

– Discussed findings/observation. 

– Concluded NIOSH’s proposed resolutions adequately 

addressed SC&A’s concerns. 

– All findings placed “In Abeyance” awaiting a revision to the 

site profile. 

• July 11, 2016: NIOSH issued Revision 01 to the PPG site 

profile (NIOSH 2016).

• August 9−10, 2016: At a full Board meeting, SC&A was 

tasked to conduct a limited review of Rev. 01 to ORAUTTKBS-0052 that focused on the resolution of “In 

Abeyance” findings. 5
Chronology (cont.)

• December 21, 2016: SC&A issued its review of 

Rev. 01 to the PPG site profile (SC&A 2016). 

SC&A concurred with said revisions and 

recommended closure of all findings and the 

observation.

• April 21, 2017: PPG WG teleconference:

– Discussed SC&A’s review.

– WG concurred with SC&A’s recommendations.

– All findings and the observation were closed.

6
A Summary of PPG Findings and 

Their Resolution

• Finding 1: Update ORAUT-TKBS-0052, Rev. 00, regarding 

the 250-workday requirement for SEC class inclusion 

based on EEOICPA Bulletins No. 06-15 and No. 07-05. 

• NIOSH Resolution of Finding 1. Section 1.3 of PPG site 

profile was amended in accordance with EEOICPA 

Bulletins No. 06-15 (DOL 2006) and No. 07-05 (DOL 

2007), which equate any 24-hour period (working or 

living on the PPG) with three 8-hour work days for 

establishing the 250-workday requirement for potential 

inclusion in the SEC class.

• Status of Finding 1. PPG WG agreed with SC&A’s 

recommendation and closed Finding 1.

7
PPG Findings and Their Resolution (cont.)

• Finding 2: Section 4.0, “Occupational Environmental 

Dose,” ignores environmental doses for PPG locations 

from fallout. 

• NIOSH Resolution of Finding 2. SC&A’s concern regarding 

exposure to fallout before 1955 was acknowledged in 

Section 4.0, “Occupational Environmental Dose.” 

Definitive guidance for assignment of unmonitored 

external exposure to fallout before 1955 is provided in 

revisions to Sections 6.2 and 6.3 and Attachment A of the 

PPG site profile.

• Status of Finding 2. Section 6.0 revisions provide the 

necessary guidance to account for unmonitored external 

exposures to fallout before 1955. PPG WG recommended 

closure of Finding 2. 8
PPG Findings and Their Resolution (cont.)

• Finding 3: DOE records may be incomplete/inaccurate and also not include 

unmonitored exposures associated with cohort badging, exposure to fallout, etc.

• Finding 4: ORAUT-TKBS-0052 does not provide a definition for unmonitored dose as it 

applies to PPG participants or any specific guidance.

• Finding 8: Use of the 50th percentile coworker dose is not justified for PPG participants 

for operations up to and inclusive of Operation CASTLE.

• Finding 9: Operation-specific dose distributions defined by the Defense Nuclear Agency 

must be adjusted to account for the minimum detectable activity value of film 

dosimeters regardless of what percentile value is employed.

• NIOSH Resolution of Findings 3, 4, 8, and 9. Limitations of personal dosimeters, their 

limited use, and other procedural practices were recognized by NIOSH as deficiencies 

that are “intractable.” To overcome these deficiencies, NIOSH proposes the use of the 

95th percentile coworker doses defined in Attachment A of the revised PPG site profile.

• Status of Findings 3, 4, 8, and 9: SC&A recognizes the difficulties NIOSH faced in the 

dose reconstruction of PPG personnel. Given the intractable nature of said limitations, 

SC&A believes that the use of coworker dose values cited in Attachment A of Rev. 01 of 

ORAUT-TKBS-0052 is a reasonable resolution. Accordingly, the PPG WG concurred with 

SC&A’s recommendation and closed Findings 3, 4, 8, and 9. 9
PPG Findings and Their Resolution (cont.)

• Finding 5: Average photon energies for fallout are well above >250 

keV. Depending on exposure geometry, a default photon energy of 

30–250 keV may not be claimant favorable.

• NIOSH’s Resolution of Finding 5. While NIOSH acknowledged 

photon energies >250 keV, its choice of 30–250 keV photon energy 

and AP geometry represent claimant-favorable dose conversion 

factors (DCFs) for all but four organs (lung, esophagus, red bone 

marrow, and bone marrow). For these four organs, revisions to 

Section 6.3.3 suggest that an AP-to-ROT geometry ratio should be 

considered for claimant favorability, with ISO geometry for cases 

requiring best estimates.

• Status of Finding 5. Because the lower photon energy and AP 

geometry generally yield higher DCF/POC values, SC&A agrees that 

NIOSH should retain its past practice to apply the DCF yielding the 

highest POC. In support of claimant favorability and with 

concurrence of the PPG WG, SC&A withdraws Finding 5. 10
PPG Findings and Their Resolution (cont.)

• Finding 6: Assignment of external dose from PPG fallout for skin 

cancers requires a beta-to-gamma dose ratio that is defined by the 

distance of the skin cancer location above the source plane. A 

second variable affecting dose is the age of fallout. 

• NIOSH’s Resolution of Finding 6. In Section 6.1 of the revised PPG 

site profile, NIOSH eliminated the default Nevada Test Site beta-togamma ratios of 1:1 and revised guidance that included beta-togamma ratios by Barss and Weitz (2006) along with efficiency 

ratios that include the effects of weathering.

• Status of Finding 6. Revisions incorporated in Section 6.1 fully 

address critical variables that include age of fallout, distance, and 

weathering impacts on the beta-to-gamma ratios that must be 

used to derive the beta dose contribution for select tissues. The 

PPG WG agrees with the revisions to Section 6.1 and recommends 

closure of Finding 6. 11
PPG Findings and Their Resolution (cont.)

• Finding 7: NIOSH’s guidance for the assignment of missed photon 

dose is based on assumptions that are not supported by facts and, 

in the face of uncertainty, are not claimant favorable.

• NIOSH’s Resolution of Finding 7. To account for unmonitored 

exposures and uncertainties of recorded film badge data prior to 

1955, NIOSH revised Section 6.0 of the PPG site profile as follows:

1) 95th percentile coworker doses should be assigned when data are 

incomplete or nonexistent. Pre-1955, recorded dose should be 

compared to 95th percentile doses and assigned larger of two doses. 

2) Sections 6.1, 6.2, and 6.3 were revised to address exposures to 

Operation Greenhouse fallout in 1951. 

• Status of Finding 7. SC&A has assessed all revisions to Section 6 of 

ORAUT-TKBS-0052 in the context of the stated finding. The WG 

concludes that current guidance adequately addresses Finding 7 

and recommends its closure.

12
PPG Findings and Their Resolution (cont.)

• Observation 1: More definitive guidance is needed for 

assignment of occupational medical dose in behalf of 

claimants with no formal affiliation with a DOE or Atomic 

Weapons Employer facility.

• NIOSH’s Resolution to Observation 1. To address this finding, 

NIOSH revised Section 3.0, which substituted protocols 

defined in Occupational X-Ray Dose Reconstruction for DOE 

Sites (NIOSH 2004) for guidance provided in Guidance on 

Assigning Occupational X-Ray Dose under EEOICPA for X-Rays 

Administered Off Site (NIOSH 2011).

• Status of Observation 1. PPG WG concurs with text revisions 

to Section 3.0 and recommends closure of Observation 1.

13
Path Forward

• Issuance of a PER addressing changes 

incorporated in Revision 01 to ORAUT-TKBS0052

• Review of said PER by SC&A

• Resolution and approval of the PER by the 

PPG WG, and selection of a sample set of 

dose reconstructions for review/compliance 

by SC&A

14
References

Barss and Weitz 2006. “Reconstruction of External Dose from Beta Radiation Sources of Nuclear 

Weapon Origin,” Health Physics, Vol. 91, No. 4 (2006), pp. 379–389.

DOL 2006. Processing Claims for Pacific Proving Grounds SEC Class, 1946 – 1962, EEOICPA Bulletin No. 

06-15, U.S. Department of Labor, Washington, DC. Sept. 27, 2006. [SRDB Ref. ID 155208] 

DOL 2007. Supplemental Guidance for Processing Claims for Pacific Proving Grounds SEC Class, 1946 –

1962, EEOICPA Bulletin No. 07-05, U.S. Department of Labor, Washington, DC. January 11, 2007. [SRDB 

Ref. ID 131050] 

NIOSH 2004. Occupational X-Ray Dose Reconstruction for DOE Sites, ORAUT-PROC-0061, Rev. 00, 

National Institute for Occupational Safety and Health, Cincinnati, OH. Dec. 1, 2004. 

NIOSH 2006. Summary Site Profile for the Pacific Proving Ground, ORAUT-TKBS-0052, Rev. 00, National 

Institute for Occupational Safety and Health, Cincinnati, OH. August 30, 2006.

NIOSH 2011. Guidance on Assigning Occupational X-Ray Dose Under EEOICPA for X-Rays Administered 

Off Site, ORAUT-OTIB-0079, Rev. 00, National Institute for Occupational Safety and Health, Cincinnati, 

OH. January 3, 2011. 

NIOSH 2014. Issues Resolution Matrix for Pacific Proving Ground Site Profile, National Institute for 

Occupational Safety and Health, Cincinnati, OH. May 20, 2014. 

NIOSH 2016. Summary Site Profile for the Pacific Proving Ground, ORAUT-TKBS-0052, Rev. 01, National 

Institute for Occupational Safety and Health, Cincinnati, OH. July 11, 2016.

SC&A 2013. Review of the Summary Site Profile for the Pacific Proving Grounds, SCA-TR-SP2013-0040, 

Rev. 1, SC&A, Inc., Vienna, VA. November 5, 2013.

SC&A 2016. Review of the Summary Site Profile for the Pacific Proving Grounds, Revision 01, July 11, 

2016, SCA-TR-2016-SP009, SC&A, Inc., Vienna, VA. December 21, 2016. 15