Rocky Flats Plant 

SEC Petition 192

David Kotelchuck, PhD, MPH

RF WG, Chairperson

Nov. 19, 2015

Oakland, California
Petition Overview 

• August 23, 2011: NIOSH received an 

83.13 petition for period of April 1, 

1952 to December 31, 1989 covering 

tritium exposures. Designated as SEC192.

• February 9, 2012: Petition qualified for 

evaluation and petition period revised 

to extend to December 31, 2005. 
Petition Overview -contd.

• October 17, 2013: Evaluation Report Rev. 

1 expanded investigation to cover Thorium, 

U-233 and Np-237.

• Board then extended existing SEC-30 (up to 

1966) to cover all employees w at least 250 

workdays between April 1, 1952 and Dec. 

31, 1983.

• SEC extension based on inability to 

estimate dose with sufficient accuracy 

exposures to Th, U-233 and Np.
Petition Overview -contd.

 At its 10/17/13 meeting Board voted to 

extend investigations for SEC-192 beyond 

12/31/83 to:

1. Evaluate the use and exposure potential for Mg- Th alloy at Rocky Flats

2. Continue to evaluate 1984-1988 period for 

Neptunium exposure potential

3. Resolve open questions with SC&A and the work 

group concerning tritium

4. Examine implications of Data Falsification issues

5. Examine exposures at the Critical Mass Lab
1. Mg-Th Alloy

• Issue raised in 2007. Allegedly shipped to RF 

to be used in plates to bullet-proof military 

trucks.

• In 2013 NIOSH did another review of Site 

Research Database (SRDB) for RF/Mg-Th link. 

More evidence of Dow/Mg-Th link, but no 

corroborating evidence for RF link.

• Other site visits undertaken. No direct RF 

link.
Mg-Th Alloy-contd.

• However worker at Dow-Madison 

plant reports shipping Mg-Th

materials to RF.

• NIOSH interviews individual. Person 

stands by report but not aware of 

other Dow facilities in Denver area.

• Dow-Madison co-petitioner alleges 

additional affidavits supporting 

RF/Mg-Th link claim. 
Mg-Th Alloy-contd.

• RF petitioner: RF worker (anonymous) says 

Mg-Th used at RF.

• NIOSH conclusion: Cannot find corroborating 

documentation of RF/Mg-Th link.

• Additional NIOSH observation: If 

undocumented Mg-Th use at RF, all alleged 

use take place between 1956 and 1976, 

during covered SEC period. 
Mg-Th Alloy-contd.

• SC&A disagrees with NIOSH:

• The worker interviewed both by 

NIOSH and SC&A provided a high 

level of “clarity and detail”.

• He specifically named 5 different 

Mg-Th alloy specifications, only two 

of which were searched for.

• Rather than “confusion”, “it is just 

as ‘possible’ that the worker had it 

right all along.”
Mg-Th Alloy-contd.

• SC&A continued:

• Dow co-petitioner reported that 400 boxes of RF 

records sit at LANL according to DOE and would 

have to be hand-searched. Estimated search 

time: 2 years.

• DOE project mgr noted that 2%–3% thorium in 

Mg-Th alloy at RF may not have been considered 

to be a reportable quantity.

• SC&A conclusion: “the receipt and use of Mg-Th

alloy material at RFP remains inconclusive”.
Mg-Th Alloy-contd.

• Given this disagreement, the RF Working 

Group decided not to ask NIOSH or SC&A to 

pursue this investigation further. Our 

reasons:

1. The failure of the intensive, years-long 

search for documentation at the plant and 

agency levels. 

2. The vast majority of cancers during yrs. of 

possible Mg-Th use compensible under 

existing SEC. (Only those with noncompensible cancers, thus not in SEC, 

might be negatively affected.)

3. Consideration of limited NIOSH resources 

of staff time and funding.
2. Neptunium-237

• NIOSH search concluded that Np237 was used at RF after the 1983 

SEC date, perhaps until 1988:

• “evidence points to a series of 

discrete tasks performed from 

1962 through 1983, involving a 

few gms. to a few hundred gms”, 

usually at request of other DOE 

facilities. Max: 300 gms in 1966.
Neptunium-237-contd.

• The only processing operation in 

the post-1983 period involving 

Neptunium was the PlutoniumNeptunium Separation and 

Residue recovery operation from 

late 1985 to the end of 1987. 

• This was a glove box operation 

involving 5 operators and one 

engineer.
Neptunium-237-contd.

• With a Pu:Np mass ratio of 6.4 and 

the far greater specific activity of 

Pu, Np operations and later waste 

clean-up were monitored via Pu air 

sampling, contamination surveys 

and bioassays (urine & body 

counts), which were consistently 

implemented in the post-1983 

period.
Neptunium-237-contd.

• SC&A studies independently confirmed the 

results of the NIOSH White Paper.

• CONCLUSION: Only one processing operation 

in the post-1983 period involved neptunium, 

and the co-presence of neptunium with 

plutonium enables radiological monitoring to 

account for any neptunium exposure 

component in a claimant-favorable manner. 
3. Tritium Exposure 

• This was the original basis for accepting SEC 

petition 192.

• Tritium emits soft beta’s and hence internal 

exposures are the main health concern.

• Prior to the 70’s the RF radiological program did 

very little monitoring for tritium because they 

felt they had limited tritium exposure potential. 

However in a 1973 incident returned triggers 

(pits) were found to emit 500-2000 Ci of tritium.
Tritium Exposure-contd.

Changes in this program were implemented as a result. 

These included:

• Increased numbers of H3 bubblers and swipe samples

• Air sampling on opening incoming used pit containers

• Urine samples for 250 workers thought to be most 

affected, followed two years later by sampling only 

among job-specific categories because the results showed 

zero positive samples

• 10% of urine samples for Pu were tested for tritium.

RESULT: Greatly reduced levels of H3 exposure by the 1980’s. 
Tritium Exposure-contd.

• Since virtually all RF workers before 1983 

covered by SEC, the crucial issue for 

NIOSH/ORAU, SC&A and the RF WG was 

whether the post-1983 tritium exposure control 

program was adequate and individual H3 

exposures appropriately assessed.

• After extensive group discussion about the 

placement of bubblers, their efficacy and H3 

sampling procedures, the WG agreed that the 

exposure control program after 1983 was 

adequate to protect workers exposed to H3.
Tritium Exposure-contd.

• Partial dose reconstructions for workers before 1973 will be 

assessed as chronic doses based on measurements just after 

the 1974 H3 incident (37.5 mr/yr), which are believed to be 

claimant-friendly over-estimates.

• Exposure measurements taken in 1975 and thereafter were 

consistently found to be less than 1 mr/yr, due to the control 

measures enacted after 1973 and the short lifetime of H3 

(12.3 yrs). 

Thus the WG agreed that H3 exposure at RF does not add 

materially to the radiation exposure burden of plant workers 

post-1983 and thus of itself does not constitute a basis for an 

SEC category beyond 1983. 
4. Data Falsification Issues

An FBI raid was conducted at RF in 1989 

concerning alleged data falsification, improper 

bioassay processing and document destruction. 

Soon after a related 1989 DOE study was 

conducted. In 2015 the FBI released its report.

1. NIOSH and SC&A interviewed a worker at RF 

who reported being ordered to destroy records, 

as well as 12 other employees. SC&A found no 

loss in “essential records” which would 

interfere with radiation dose reconstruction, 

nor evidence of data falsification. 
Data Falsification Issues-contd.

2. Another interviewee made statements 

about the inadequacy of fume hoods, stack 

samples and improper handling and/or 

preparation of environmental samples. 

“From a radiological perspective, NIOSH 

finds no scientific basis for concluding that 

the issues raised regarding environmental 

samples would compromise radiological 

count results.”
Data Falsification Issues-contd.

3. Yet another interviewee raised the issue of 

dosimetry technicians writing down dose 

rate information in pencil, which would 

allow RFP management later to direct 

changes to keep production going. This 

impacts field survey instruments, used for 

comparisons only. The primary sources of 

dose reconstruction data are personnel 

dosimeters and bioassays, assessed in labs.
Data Falsification Issues-contd.

4. SC&A reviewed 8 documents mentioned in 

the NIOSH White Paper. It concluded “the 

documents were concerned with other 

aspects of RFP operations or environmental 

issues, rather than data falsification, record 

destruction, or bioassay data, that would 

potentially impact the ability to perform 

adequate dose reconstructions.”
Data Falsification Issues-contd.

• Based on its interviews, analyses and 

evaluation of the 1989 FBI raid report, NIOSH 

concluded that “there exists a sufficient 

quantity of individual external monitoring 

data to support the assessment of RFP 

personnel external doses.” SC&A 

corraborated this conclusion. 
Data Falsification Issues-contd.

• In addition to its basic support of the 

conclusions of the NIOSH White Paper, SC&A 

expressed concern that data used to generate 

radionuclide intakes were impacted by the 

environmental sampling/data issues that 

surfaced after the 1989 FBI raid and the 1989 

DOE investigation & evaluation that followed.

• The RF WG having read the associated White 

Papers & heard the presentations agreed with 

the NIOSH conclusions and referred the 

env./occ linkage issue to the Subcommittee 

on Procedures Review.
Data Falsification Issues-contd.

• Claimant representatives have written a lengthy response to 

the NIOSH White Paper:

• ‘NIOSH combines all of the issues raised by the petitioners 

and their relationship to Building 123. Each of the issues raised 

are separate concerns. Some concerns may be related to 

Building 123 but not all of the issues are. Therefore, each of 

the issues needs to be addressed on an individual basis. It is 

the petitioners’ position that the problems associated with 

each individual concern is sufficient for NIOSH to determine 

they cannot reconstruct dose with sufficient accuracy. It is 

even more evident that, when combining the issues, serious 

questions are raised with the bioassay documents NIOSH uses 

to reconstruct dose. “ 
Data Falsification Issues-contd

• Claimants also present evidence from the “Final Historical 

Release Report for the Rocky Flats Plant, June 1992” of 

additional destruction of RF records. 

• Finally they assert: “It is clear the accuracy of the 

dosimetry records NIOSH has for Rocky Flats claimants 

needs to be questioned. These records are unreliable. 

Therefore, NIOSH must admit that dose reconstruction 

cannot be performed with reasonable accuracy, and must 

recommend expanding the SEC.”

NIOSH is currently writing a response to this communication.
5. Critical Mass Lab

Operations in the Critical Mass Lab (CML) took 

various assemblies and radioactive materials to 

criticality levels. NIOSH White Paper notes: 

“Radioactive materials at the CML included the 

nuclear fuels and sealed radioactive sources used 

in criticality experiments. Fission and activation 

products generated in the fuels, building materials 

and fixtures as a result of the nuclear criticality 

experiments conducted there are an additional 

source of radiological exposure.” 
Critical Mass Lab-contd.

White Paper conclusion: External radiation 

exposure to CML workers and staff is accounted 

for by Rocky Flats’ personnel dosimetry program, 

which assigned radiation dosimeters to all 

workers. The personnel dosimetry program also 

included periodic bioassay (urinalysis and body 

counts) that focused primarily on identifying 

uranium and plutonium intakes. Also finds little 

radiation from fission & activation products. 

The WG accepted the Paper. 
Critical Mass Lab-contd.

• However on the 7/14/15 RF WG conf. call, 

last surviving of 3 senior scientists of the CML 

(1964-1986), joined the discussion and 

expressed strong disagreement with the 

conclusions of the NIOSH White Paper. He 

requested a personal interview at a later 

time, which was agreed to and conducted on 

10/13/15.
Critical Mass Lab-contd.

• During the interview the CML scientist 

argued that no one can bound the neutron 

flux in the lab’s near criticality experiments. 

The radiation levels at CML were not properly 

documented, he asserted, and RF did not do 

body counts on the lab’s 30-35 employees, 

only lung counts and (irregularly) urinalyses.

• He also disputed the ability to put upper 

bounds on the neutron flux via reactors’ 

energy output.
Critical Mass Lab-contd.

• In addition to exposures to its full-time 

employees, the CML scientist reported that 

during the 1980’s typically 100-200 non-CML 

RF employees entered the lab annually to 

observe ongoing experiments.

• At the conclusion of this discussion, NIOSH 

staff agreed to review and modify as 

appropriate its White Paper on CML, and is 

currently drafting its response. 
Critical Mass Lab-contd.

• As part of this effort NIOSH will do a data 

capture from LANL re CML. This data is 

expected to be ready for inspection in 

January 2016. 
Cobalt-60 Exposure

• This past Spring claimants raised concerns about 

radiation exposure from the 600 Ci Cobalt-60 

source at RF, and presented information from 

DOE (via FOIA) as well as employee testimony 

alleging lack of proper exposure protection 

during Co-60 removal from RF.

• At the 10/28/15 RF WG meeting, NIOSH staff 

person Rutherford said that proper, standard 

protective measures were employed during the 

Co-60 removal. He will respond further at a later 

time. 
Issues Resolution RF WG (11/19/15)

 At its 10/17/13 meeting the Board charged the RF WG 

to investigate the following issues for the period 

beyond 12/31/83 to:

1. Evaluate the use and exposure potential for Mg- Th alloy at Rocky Flats – CLOSED 

2. Continue to evaluate 1984-1988 period for 

Neptunium exposure potential – CLOSED 

3. Resolve open questions with SC&A and the work group concerning tritium – CLOSED 

4. Examine implications of Data Falsification issues – CLOSED for WG, with referral to SC on Proc. Review

5. Examine exposures at the Critical Mass Lab – OPEN . 

LANL data capture in January, 2016
Additional Issue 

• Cobalt-60 exposures – raised in WG by 

claimants. IN PROCESS