Disclaimer 

This document is made available in accordance with the unanimous desire of the Advisory Board 

on Radiation and Worker Health (ABRWH) to maintain all possible openness in its 

deliberations. However, the ABRWH and its contractor, SC&A, caution the reader that at the 

time of its release, this report is pre-decisional and has not been reviewed by the Board for 

factual accuracy or applicability within the requirements of 42 CFR 82. This implies that once 

reviewed by the ABRWH, the Board’s position may differ from the report’s conclusions. Thus, 

the reader should be cautioned that this report is for information only and that premature 

interpretations regarding its conclusions are unwarranted. 

8.0 DATA COMPLETENESS EVALUATION 

The Advisory Board’s criteria for evaluation of SEC petitions include several that relate to the 

data underlying dose reconstruction (ABRWH, January 2006).1

 These criteria fall under the 

general rubric of the “credibility and validity of the dataset.” The intent of these criteria relates 

to NIOSH’s ability to perform dose reconstructions: 

For each petition evaluation, NIOSH will typically review the available exposure 

data for that site and then focus on a few key sets of exposure data (including 

exposure sources) to determine if those data at that site are adequate for 

completing individual dose reconstructions for all members of the class.

[ABRWH, January 2006]

The Board elaborated on the meaning of the term “credibility and validity of the dataset” by 

specifying the following criteria: 

• “1. Pedigree of the Data” This includes determining “.the relation of the exposure 

monitoring to documented activities at the site during that time period” and ensuring that 

“secondary sources of data ...are consistent with the original data set....” 

• “2. Methodology” This includes an evaluation of “the documented methodology for the 

data set including whether reliable corrective estimation procedures have been applied 

and are appropriate.” 

• “3. Relation to Other Sources of Information” This includes a demonstration that “the 

data are appropriate for... estimating the maximum plausible dose for any member of the 

class.” 

• “4. Internal Consistency” of the dataset. 

• “5. Representativeness” of the dataset including considerations of the various periods, 

areas, types of work and processes, source terms, and adequacy of data to be 

“representative of the highest exposed individuals within the class.” 

 1

 Report of the Working Group on Special Exposure Cohort Evaluation, draft dated January 16, 2006, 

approved by the Board at its January 24-26, 2006 meeting in Oak Ridge, TN. 

RFETS SEC Petition Review 1 Working Draft – February 15, 2007 
The procedures approved by the Board for its contractor in evaluating SEC petitions and in 

reviewing NIOSH’s Evaluation Reports on SEC petitions also involve an investigation of the 

completeness of the internal and external dose datasets that NIOSH proposes to use for dose 

reconstruction for any member of the class. (SC&A June 12, 2006, p. 24).2

The review of NIOSH’s Evaluation Report by the Board’s Working Group and the Board’s 

involved detailed investigations of various aspects of the credibility and validity of the dataset. 

NIOSH also did a considerable amount of work investigating the issue in the process. 

Initial inquiries focused on the completeness of the HIS-20 electronic database and its 

relationship to the underlying data. Comparison of the database with information in logbooks 

and claimant files revealed that the HIS-20 database was not complete and that workers whose 

employment ended prior to 1977 may not be represented in it. Another database, the CER 

database, was also found to be incomplete. NIOSH, in response, stated that it would rely on 

individual dose records in DOE files as the principal source of data for individual dose 

reconstruction and on the HIS-20 electronic database for co-worker models. As a result, the 

issue of the completeness of the data in the DOE files arose, since that is the primary data on 

which NIOSH is relying for individual dose reconstruction. This section examines the issue of 

the completeness of individual dose data as reflected in Rocky Flats claimant files. 

This completeness investigation was necessitated by the fact that there is no complete 

compilation of dosimetry data that reflects essentially all the data in the DOE files. Gaps in data 

– that is, periods when there were no measurements whatsoever – indicate a need for methods to 

fill those gaps. These gaps are essentially different from zeros in the data records that reflect 

measurements below the detectable limit that can be filled in various ways, including by using 

the Limit of Detection (LoD) or LoD/2 or some value in between. Co-worker models may be 

needed if gaps are significant or if whole groups of workers were not monitored at certain 

facilities or in certain periods or both. 

SC&A conducted a broad investigation of the completeness of Rocky Flats external and internal 

monitoring data in claimants’ DOE files, using minimal criteria for completeness, to ascertain 

whether substantial gaps that needed to be filled in exist. This broad investigation is to be 

distinguished from a more detailed evaluation that would, for instance, involve a review of each 

badging cycle for external dose.

SC&A conducted two types of completeness evaluations. The first was to examine external and 

internal dose data in DOE responses in the records of 32 randomly selected claimants. The 

second consisted of examining the DOE responses in the records of 20 claimants that were 

judged by Rocky Flats in the 1990s to have high cumulative radiation doses. The randomly 

selected cases allow a picture to be developed about the general extent of the gaps in Rocky Flats 

worker records. This investigation does not tell us why those gaps exist. It only alerts one to 

their existence and approximate extent. An examination of the records of claimants with high 

cumulative exposures allows a preliminary view of whether there is a basis to fill in the gaps in 

 

2

 SC&A, Board Procedures for Review of Special Exposure Cohort Petitions and Petition 

Evaluation Reports, June 12, 2006.

RFETS SEC Petition Review 2 Working Draft – February 15, 2007 
dosimetry data in the rest of the workers population, should such gaps be found to exist. In each 

case, the investigation of gaps related to the data that are in DOE files for a particular claimant. 

SC&A also did a preliminary evaluation of the job records of the 20 claimants with high 

cumulative exposures in order to ascertain whether a pattern existed for certain gaps in the 

external dose records. This evaluation does not cover external dose gaps in 1969, which are 

discussed under a separate heading. 

The 32 random claims were selected in three waves. An initial set of 4 was chosen from among 

Rocky Flats dose reconstructions already audited by SC&A. These were among the cases 

randomly selected by NIOSH and presented to the Board, which selected the cases from across 

the weapons complex to be audited. The next eight (Wave 2) were obtained by picking the first 

Rocky Flats case with more than five years from 1-999 claimant numbers on the NIOSH R 

Drive, then one from the 1,000 to 1,999 group, one from the 2,000 to 2,999 group, until there 

were a total of 8 cases. A preliminary analysis was conducted to determine whether the gaps 

indicated were sufficient to warrant a further inquiry. Finally, the last 20 (Wave 3) were selected 

using a randomized search procedure, with the added limitations that: 

• Two periods, 1951-1963 and 1964-1992, be represented among those selected so that 

they could be studied separately. This is because Rocky Flats integrated its security and 

film badge in that year. This made the earlier period a statistically different distribution – 

and indeed, data on the fraction of workers monitored in the first period indicate a fairly 

steady increase with the years from start-up through the early 1960s. The data show a 

sudden jump in the fraction of employees badged in 1964. See Table 8.1, which is taken 

from a NIOSH paper on Rocky Flats badging practices, which is reproduced, in full, in 

Attachment 27. 

• Each claimant file selected represents a claimant who worked at Rocky Flats for at least 

five years. 

• The sampling was done without regard to whether dose reconstruction had been 

completed or not. Only files pulled by NIOSH from the dose reconstruction process (17 

out of 1,165) were excluded from the sampling. 

The sampling procedure for selecting the 20 cases is described in Attachment 28. 

The total of 32 cases was designed to provide a reliable picture of the gaps in Rocky Flats 

workers’ DOE records. Table 8.1, which catalogs the proportion of workers badged at Rocky 

Flats, by year, shows that we should expect larger gaps in the 1951-1963 period for external dose 

than in the 1964-1992 period. Note that the frequency of monitoring declined again beginning in 

1992. This was the year that production ended and the transition to decommissioning of Rocky 

Flats began. Decommissioning was formally started in 1993. 

Table 8.1. Percent Badged. 

Year Badged Year Badged Year Badged Year Badged Year Badged Year Badged 

1951 1961 77% 1971 94% 1981 96% 1991 91% 2001 73% 

1952 5% 1962 78% 1972 94% 1982 96% 1992 82% 2002 72% 

1953 33% 1963 75% 1973 94% 1983 97% 1993 80% 2003 56% 

1954 34% 1964 93% 1974 98% 1984 96% 1994 65% 2004 40% 

RFETS SEC Petition Review 3 Working Draft – February 15, 2007 
1955 43% 1965 93% 1975 97% 1985 98% 1995 65% 2005 25% 

1956 53% 1966 96% 1976 96% 1986 97% 1996 67% 

1957 61% 1967 95% 1977 97% 1987 98% 1997 79% 

1958 63% 1968 91% 1978 98% 1988 98% 1998 83% 

1959 63% 1969 74% 1979 98% 1989 98% 1999 83% 

1960 71% 1970 90% 1980 97% 1990 96% 2000 80% 

Source: ORAU analysis of RFP claimant files 

Source: NIOSH paper Badging Practices at Rocky Flats, no date, transmitted to SC&A on December 7, 2006. 

Figure 8.1 shows the data in Table 8.0 in graphical form. 

External Gamma Monitoring

0

20

40

60

80

100

1950 1960 1970 1980 1990 2000 2010

Year

% monitored

Figure 8.1: Proportion of workers monitored for external dose at Rocky Flats 

Source: NIOSH paper Badging Practices at Rocky Flats, no date, transmitted to SC&A on December 7, 2006. 

The DOE dose records of the 32 claimants were divided into two periods, 1951-1963 and 1964 

to 1992. This is to account for the fact that a combined ID and film badge was issued in 1964, 

which resulted in almost all workers being badged (but not all – see below). In addition, separate 

tables were created for external dose (deep gamma) and internal dose. If, in any year, there were 

no external dose records at all (even zeros), but only blanks, that year was counted as a gap in 

external dose data. (The term “gap” is used equivalently to mean a blank in the records or no 

measurement indicated in the record. It does not include zeros in the record, which are counted 

as measurements at less than the limit of detection.) Note that counting a year as one that has 

data does not affirm that there are complete data within that year – that is, it does not make a 

statement one way or another whether there is a record for each badge cycle. Similarly, for 

internal dose data, a year counted as a gap in the data is one in which there was no bioassay 

(urine or fecal) record and no in vivo count. If there was a data point for any one of these 

categories in a given year, it was not counted as a year without data. Gaps for partial years at the 

start of employment and at the end of employment were not counted. (The initial and final year 

data were rounded to zero, half year or full year as follows: – 0 to 2 months = zero, 3 to 8 months 

= half year, nine months or more = full year). SC&A also compiled cumulative data on the data 

gaps. In these cumulative compilations partial initial and final years were counted according to 

the rounding scheme described. 

RFETS SEC Petition Review 4 Working Draft – February 15, 2007 
In addition to the analysis of 32 cases randomly selected, a sample of 20 cases from among those 

judged in the 1990s to have the highest cumulative doses (internal committed dose equivalent 

plus external deep dose) was examined to assess completeness of records for those workers. The 

exposure assessment was carried out by ORAU in the 1990s as a retrospective. This part of the 

completeness evaluation has particular relevance for development of co-worker models.3

8.1 EXTERNAL DOSE – RANDOM SAMPLE 

Table 8.2 shows the analysis for the external dose records for the 32 claimants in the random 

sample. 

Table 8.2: Rocky Flats External Dose Data Completeness Analysis – Random Samples 

Period #of workers 

# with gap of 1 

yr or more 

(Note 1) 

% workers 

with gaps 

of 1 yr or 

more 

(Note 1) 

Cumulative 

years 

employed 

Cumulative 

gap -- 

years 

% 

cumulative 

gap 

1951-

1963 14 4 29% 76.5 16.0 21% 

1964-

1992 30 

10 

(Note 2) 33% 368 

37.0 

(Note 3) 10% 

Notes: 1. First or last partial year gaps not counted in this column. 

2. Of the 10 employees with gaps of one year or more in 1964-1992, four had gaps only in 1992 

3. 1969 gaps data may be for part of the year or the full year. 1969 data gaps are not counted as full year gaps in this 

compilation. The 1969 issue is briefly addressed below and more fully elsewhere in this report. 

4. A gap is recorded for the year if there are no film badge or TLD data at all for that year. Zero entries are counted 

as positive indications of recorded data. Only blank records are included in the compilation of the gaps. 

The percentage cumulative gap in the external dose data was greater in the 1951-1963 period 

than in the 1964-1992 period. This result confirms the data compilation by NIOSH presented in 

Table 8.1 above, which shows that a significant proportion of workers were not badged in early 

period. The proportion of badged workers went from 5% in 1952 to a high of 78% in 1962. 

Overall, about 21% of the cumulative years worked by the 14 employees had no external dose 

records (partial years counted as 0 or 0.5 years, as noted above). 

The proportion of workers with at least a one-year gap was about the same in the two periods 

(about 30%). However, the high value for the latter period is largely due to the transition year of 

1992. Four of the ten workers with a gap of at least one year had a gap only in 1992. An 

investigation into job types may yield insight into the reasons. If one leaves out these four, 20% 

of the workers with a gap of at least one year in their external dose records. As noted, this 

analysis does not include partial year gaps. It just requires that one record be present in a given 

year for that year to be excluded from the compilation of data gaps. It is therefore a minimal 

criterion of completeness for external dose data. Issues related to dose reconstruction are 

discussed in the section on highly exposed workers. 

 3

 The detailed compilations of the claimant data are not included in this draft report. They may contain 

Privacy Act information. They spreadsheets have been sent to the CDC for evaluation as to Privacy-Act-related 

content. 

RFETS SEC Petition Review 5 Working Draft – February 15, 2007 
We found several records with gaps for all or part of 1969. This also reflects the cumulative data 

compilation of monitoring frequency provided by NIOSH and discussed above. However, a 

specific problem appears to affect 1969 external dose data. In that year, Rocky Flats 

management decided not to read the film badges of workers on a three-month badge cycle. This 

was stated in the March 1969 monthly Status report: 

Quarterly badges for the non-Pu areas will no longer e read routinely, except for 

a few higher dose risk groups. The film will be changed as usual, but will not be 

read unless circumstances warrant. [Piltingsrud 1969]4

It is not clear whether and when this policy was rescinded. Not reading film badges that were 

issued and then handed in appears to SC&A to be a questionable practice and even apparently 

surprised NIOSH/ORAU consultant and Rocky Flats dose expert Roger Falk (see Attachment 

29, for the notes of SC&A’s interview with him). 

SC&A notes here that there was also a problem of blank external dosimetry records before 1969 

and after the start of the integration of the ID badge and the film badge in 1964; it continued after 

1970. For instance, one of the workers in the random sample of 32 had external dosimetry gaps 

(blanks) from 1963 to 1973 (inclusive). Despite the universal badging policy supposedly in 

effect at the time due to the integrated ID-film badge, NIOSH stated that he/she was not issued a 

badge (November 6, 2006 Working Group meeting transcript, pp. 76-79). It is not clear how 

NIOSH differentiated this from non-reading of issued badges. In any case, this practice likely 

relates to workers judged to not to have high exposure potential; it could create complications for 

some groups of workers for estimating dose (see discussion below and in the analysis of the 1969 

external dose records). 

8.2 RANDOM SAMPLE – INTERNAL DOSE 

Table 8.3 shows the summary data for the 32-claimant random sample for internal dose data. 

Table 8.3: Rocky Flats Internal Dose Data Completeness Analysis – Random Samples (Note 1) 

Period #of workers 

# with gap of 1 

yr or more 

(Note 2) 

% workers 

with gaps 

of 1 yr or 

more 

(Note 2) 

Cumulative 

years 

employed 

Cumulative 

gap -- 

years 

% 

cumulative 

gap 

1951-

1963 14 4 29% 76.5 9.0 12% 

1964-

1992 30 22 73% 368.0 122.5 33% 

Notes: 1. A gap for a full year is recorded if there are no bioassay data (urine or fecal) and if there are no in vivo 

data. A single measurement in any of these categories is counted as a year with data. This approach cannot be 

directly related to dose reconstruction feasibility but provides a modest test of data availability for internal dose. 

2. First or last partial year gaps data not counted in this column. 

 4

 C.W. Piltingsrud, Status Report – Dosimetry – March 1969, April 8, 1969. 

RFETS SEC Petition Review 6 Working Draft – February 15, 2007 
Surprisingly, nearly three-fourths of the workers in the random sample had at least one year of 

no internal dose measurements in the 1964-92 period, though the total cumulative working years 

with no internal dose records was about one-third. There were smaller internal dose 

measurement gaps in the early period. The issues raised by these gaps as they concern internal 

dose reconstruction are discussed in the section on highly exposed workers. 

8.3 SAMPLE OF HIGHLY EXPOSED WORKERS 

As noted, SC&A also analyzed the DOE files of 20 Rocky Flats claimants who were assessed as 

having high cumulative exposure in a retrospective analysis done in the 1990s. That analysis 

categorized workers into groups, numbers “1” through “4”, with “1” representing the lowest 

cumulative exposures (CDE internal plus external and “4” representing the highest exposures). 

SC&A chose 10 claimants from Group 4 and 10 from Group 3 for analysis. The selection was 

made as follows. SC&A asked NIOSH to provide the full lists of claimants in Group 3 and 

Group 4. NIOSH provided a list of 22 Group 4 claimants. SC&A selected the first five and last 

five from this list. For Group 3, NIOSH sent a list of 35 claimant numbers. SC&A selected 

approximately every third one from this list until it had a total of 10.

There were no full-year gaps in internal dose data for this group of 20 workers. This applies to 

both periods. The early period includes 63 cumulative years of employment in the 1950s. On the 

face of it, there would appear to be a sound database for beginning an analysis of the feasibility 

of one or more co-worker model for all members of the class through 1992. SC&A has not 

performed such an analysis. However, SC&A recommends that the analysis should include a 

review of the data related to workers with high cumulative exposure. This would allow NIOSH 

to examine the job types represented to determine if they include all the ones with high internal 

exposure potential relative to the various source terms present at Rocky Flats, or if the exposures 

for the job types that are represented bound those that are not represented for various periods 

where production operations changed, or other factors, such as materials brought in or processed, 

changed. Further, it is important to verify whether the available data are sufficient to reconstruct 

doses due to incidents, especially when exposure was to materials of high or medium solubility. 

Specifically, in view of the large proportion of workers (nearly three-fourths) in the random 

sample who had a gap of at least one year in their internal dose records, it is essential that an 

analysis of job types of Group 3 and Group 4 workers be done relative to the workers who have 

gaps in their data, before a co-worker model can be deemed to be suitably claimant favorable. 

The picture regarding external dose is somewhat different. There are essentially full-year gaps in 

external dose data records for this group of 20 claimants from 1960 onward. However, there are 

considerable gaps for the 1951-1959 period, notably for claimants in Group 3. Specifically, 

about 62% of the cumulative employment years for Group 3 workers were lacking any external 

dose data in this period; the total for Group 4 was 19%. Most of the gaps relate to the initial 

years of employment. 

The gaps in the 1950s most likely reflect the partial external dose monitoring for Rocky Flats 

workers, discussed above. SC&A sought an explanation for these gaps from Roger Falk, during 

an interview with him as a site expert, and he responded as follows: 

RFETS SEC Petition Review 7 Working Draft – February 15, 2007 
They may have started work in a non-radiation area or in a lower job 

classification. Rocky Flats was a coveted place to work. What I have observed 

and known to have happened was that anyone would apply for a low-level job, 

such as Janitor, and work their way up into better positions as he proved himself. 

I don’t know if it happened in the cases that you looked at. [Attachment 29] 

SC&A did a preliminary analysis of the job cards of both Group 3 and Group 4 workers in order 

to determine whether any pattern emerged in a screening analysis. It appears that most of the 

full-year data gaps in the 1950s are associated with work in Production Plant B, where uranium 

(DU and EU) was processed. There were also some gaps in Building 81, the QC lab, and the 

“pipe shop.” There were no full-year gaps external dose data (as defined above) in Production 

Plant C, where plutonium was processed. SC&A confirmed Dr. Falk’s observation that many 

workers started as janitors or laborers and worked their way up. However, the progression was 

rather rapid, and the data gaps do not relate mainly to the period of employment in nonradiological jobs. On the contrary, they are mainly in the years when the employees in question 

were in radiological areas, mainly in Production Plant B. A review of the job cards therefore 

provides a reasonable explanation for the gaps in the data. The remaining question relates to the 

relationship of the gaps to creating a co-worker model. 

Uranium-238 has a much higher potential for shallow dose than plutonium-239/240, due to the 

beta-emitting decay products of uranium-238 -- thorium-234 and protactinium-234m. Further, 

uranium foundry operations resulted in separation of these two decay products, which flowed to 

the surface of the uranium. In those operations, beta dose rates was as high as 2,000 to 3,000 

mrad/hour on castings of DU in the early years, which is an order of magnitude higher than 

equilibrium contact beta dose from uranium metal (Putzier 1982, pp. 74-75 of the pdf file). 

Contamination of workplace surfaces with dust high in Th-234 and Pa-234m could result in very 

high and non-uniform skin doses. Since shallow dose measurements from later years may not be 

reflective of early radiological conditions, it may be difficult to use later data to retrospectively 

estimate shallow dose or even deep dose for uranium workers. Concentrated, non-equilibrium 

areas of contamination with Th-234 and Pa-234m not shielded by massive uranium metal could 

also lead to higher deep exposure rates from the various gamma photons associated with these 

radionuclides (131 KeV, 1.9 Mev, 63 KeV, 92 Kev). One way of approaching the problem 

would be to examine whether there are sufficient data from the non-plutonium areas in the 

periods of high exposure potential (such as the early period) that would allow the creation of a 

co-worker model that would meet the test of 42 CFR 83 for dose reconstruction sufficient 

accuracy. 

The possible use of data from plutonium areas for co-worker models could also be investigated. 

However, it cannot be assumed a priori that those areas exceeded the dose to workers in the 

uranium foundry or similar work areas in all periods. We note in this context that, according to 

NIOSH, americium-241 was not present in appreciable amounts in plutonium at Rocky Flats in 

the 1950s (see Chapter 6 on Internal Dose, sections on Other Radionuclides). Am-241 was 

presumably the main source of external gamma dose in the plutonium areas in Rocky Flats. On 

the other hand, early plutonium buttons from Savannah River Site had high surface 

contamination with fission products leading to high external dose rates in some areas in the 

initial period of receipts from SRS (Putzier 1982). In view of these facts, a comparative analysis 

RFETS SEC Petition Review 8 Working Draft – February 15, 2007 
of the external exposure potential in Production Plant B compared to Production Plant C is 

necessary before data from the latter can be applied to shallow or deep gamma dose to fill the 

data gaps in worker external dose records. 

Finding regarding external dose co-worker model for the 1950s: Significant gaps in external 

dose data for the 1950s were identified, as discussed above. The main issues therefore center on 

the nature of the gaps in relation to monitored workers and whether they can be filled by 

appropriate dose reconstruction procedures or coworker models. The gaps appear to be 

associated with work in non-plutonium areas. A comparative analysis along the lines suggested 

above is needed for the 1950s in order to determine whether the available data are adequate to 

yield a scientifically robust, claimant favorable co-worker model for the 1950s. NIOSH has not 

made the type of detailed analysis that would be needed to establish the feasibility of filling in 

the data gaps for all workers in the class, including workers such as uranium foundry workers in 

the 1950s. Lacking such an analysis, SC&A cannot come to a definitive conclusion regarding 

the feasibility of dose reconstruction with sufficient accuracy for all members of the class for 

external dose, notably beta dose. This is not to say that it cannot be done, but that it will require 

considerable work to demonstrate it. (The data gaps in 1969 are analyzed elsewhere in this 

report.) 

Conclusion regarding internal dose co-worker model: Since the internal dose data for highly 

exposed workers do not show annual gaps, it is likely that the gaps in internal dose can be filled 

by one or more suitable co-worker models designed to appropriately reflect job types and periods 

of employment. 

8.4 OTHER ISSUES REGARDING COMPLETENESS OF DOSE DATA 

During the Working Group’s deliberations, NIOSH stated that subcontractors were not 

necessarily badged even in the period when the ID badge and film badged were integrated into 

one device. The data provided by NIOSH and quoted above confirms that the proportion of 

monitored workers did not reach 100 percent at any time, but stayed a few percent below that 

throughout the period of production. Subcontractor workers, as with any RFP workers in the 

1964-1991 period, were required to be monitored when they entered radiological areas. 

(Working Group meeting transcript, pp. 74-78). 

Conclusion regarding unbadged subcontractor workers: While NIOSH has provided no 

documentation to confirm that the requirements for subcontractor workers to be badged when 

they entered radiological areas were uniformly followed, SC&A has found no evidence to the 

contrary. Specifically, we have not found any systemic violation of the policy that would have 

resulted in unbadged subcontractor workers going into areas with radiological exposure 

potential. The NIOSH statement was made at the Working Group meeting during a discussion of 

the dose record of a prime contractor worker who had an 11-year external dose gap. Ten years 

of that – 1964-1973 (inclusive) – was in the universal badging period after 1964 when the ID and 

film badges were integrated into a single device. SC&A also notes that between 1964 and 1991, 

the proportion of unbadged workers was small in almost all years (less than 10 percent and 

generally in the 2% to 6% range – see Table 8.1 above). Some verification of enforcement 

RFETS SEC Petition Review 9 Working Draft – February 15, 2007 
would be desirable to ensure that unbadged subcontractors did not work in radiological areas. 

One possible verification procedure might relate to clean up after fires, such as those in 1965 and 

1969. An investigation of the problem of not issuing badges to prime contractor workers not 

thought to have exposure potential or not reading issued badges is also needed to characterize 

their exposure potential (see separate discussion of the increase in zero external dose entries in 

1969). 

Overall conclusions regarding completeness 

SC&A has carried out an extensive analysis of the issue of completeness of dosimetry data in 

DOE files, which are stated by NIOSH to be the primary basis for dose reconstruction for 

individual claimants. This included a random sample of 32 claimant files and a selected sample 

of 20 files of claimants who were assessed by Rocky Flats in the 1990s to have high cumulative 

exposure (external plus CDE internal). This investigation has provided SC&A with the basis to 

come to some firm conclusions about some aspects of the gaps in Rocky Flats data. The caveat 

“some” is related to the fact that we used minimal completeness criteria – it required a gap in 

measurements for a full year for that year to be included in the incomplete-year total. Intra-year 

gaps were not considered; nor were the data evaluated according to radionuclide source terms. 

Our overall conclusions for the period 1951-1992 are as follows: 

• There are substantial gaps in external dose data for the 1950s. The investigation of 

the high cumulative exposure cases indicates that these gaps are likely related to work 

in Plant B and some other areas not related to plutonium processing facilities. It 

might be possible to fill in the gaps using data from Rocky Flats and other sites (for 

uranium external shallow and deep dose), provided that additional analysis as regards 

claimant favorability relating to actual working conditions is carried out. However, 

no firm conclusion is possible at the present time since NIOSH has not done the 

requisite analysis, including, for instance, about the shallow dose exposure conditions 

in uranium foundry operations in the 1950s. 

• There are large gaps in internal dose data, notably for the 1964-1992 period, during 

which almost three-fourths of the workers had gaps of at least one year in internal 

dose measurements. About one-third of the cumulative years of employment had no 

measurements in the 1964-1992 period. These observations relate to the random 

sample. 

• The bioassay data for the highly exposed workers have essentially no gaps for full 

years. Since the internal dose data for highly exposed workers do not show annual 

gaps in any period to 1992, it is likely that the gaps in internal dose can be filled by 

one or more suitable co-worker models designed to appropriately reflect job types and 

periods of employment. 

RFETS SEC Petition Review 10 Working Draft – February 15, 2007