Memo – Response to KCP Matrix Issues 1 SC&A – April 20, 2015 

NOTICE: This memo has been reviewed for Privacy Act information and has been cleared for distribution. 

However, this report is pre-decisional and has not been reviewed by the Advisory Board on Radiation and Worker 

Health for factual accuracy or applicability within the requirements of 42 CFR 82.

MEMO 

DATE: April 20, 2015 

TO: KCP Work Group 

FROM: Joe Fitzgerald, SC&A 

SUBJECT: SC&A’s Evaluation of NIOSH’s January 2015 Response to KCP SEC Matrix Issues 7, 

15, 17, 18, and 20 

SC&A was tasked by the Kansas City Plant (KCP) Work Group (WG) at its January 20, 2015,

meeting with further evaluation of open issues pertaining to NIOSH’s Special Exposure Cohort 

(SEC) evaluation report (SEC-00210) for that site. These included the subject issues, as well as 

issues 11 (neutron dose) and 13 (Mg-Th alloy), which are being or have been addressed 

separately. 

Following further review of available documents, an onsite data capture with former worker 

interviews at KCP, and an additional review of classified information at the Department of 

Energy (DOE), SC&A provides the following assessment of these open issues. 

Issue 7 – Radioactive Waste: The WG determined this issue to be “open” pending additional 

document searches and worker interviews for information regarding KCP radwaste handling in 

the 1960s, as well as in the 1980s, with specific attention to whether a radwaste handling group 

existed, or whether project personnel handled radwaste during these time periods (names of 

contact personnel were identified at the WG meeting; it was also mentioned that personnel 

handling waste in the 1980s were disqualified because they were illiterate).

SC&A Assessment: Interviews conducted at KCP in March 2015 ([Worker 5], [Worker 1], and 

[Worker 4]) indicated that unmonitored laborers collected the uranium and Mg-Th cuttings and 

chips from the lathe machines for placement in 55-gallon drums, which were then transported to 

the KCP central waste facility. These wastes were coated in lathe oil and were apparently 

collected from under the machine and from the floor, and loaded into the drums using a 

“pitchfork” implement. Laborers were neither badged nor bioassayed.1It was also noted that 

while worker movement into and out of these radiological operating areas was restricted by 

security access badges until the late 1960s-early 1970s, this restriction was relaxed thereafter to 

anyone with a general “Q” clearance ([Worker 2]). While there was clearly an exposure 

potential, a remaining question is whether it can be considered comparable to the lathe operators, 

who were monitored. SC&A recommends that NIOSH review the relative exposure potential of 

the custodial/laborers who routinely collected and drummed contaminated waste, as compared 

with the operators who conducted the machining of depleted uranium (DU) and Mg-Th, with an 

objective of informing the WG as to whether these exposures are comparable (or for the former, 

lower) and can therefore be adequately bounded using available monitoring data.

 

1

 Albeit, at least one exception was noted; a laborer who had access to a restricted radiological area was 

badged. 
Memo – Response to KCP Matrix Issues 2 SC&A – April 20, 2015

NOTICE: This memo has been reviewed for Privacy Act information and has been cleared for distribution.

However, this report is pre-decisional and has not been reviewed by the Advisory Board on Radiation and Worker 

Health for factual accuracy or applicability within the requirements of 42 CFR 82.

Issue 15 – Thorium oxide operations: SC&A had previously noted for this issue that the 

NMMSS inventory information for “unalloyed thorium” had not yet been reconciled with onsite 

records, given the lack of operational information located to date. The current Nuclear Material 

Management and Safeguard System (NMMSS) database custodian at KCP is relatively new to 

the position and has been unable to offer any insight. SC&A was charged by the WG with 

completing its review of Site Research Database (SRDB) records identified by NIOSH from the 

last data capture, and for both NIOSH and SC&A to continue to look for relevant records while 

conducting onsite searches at KCP.

SC&A Assessment: SC&A’s review of KCP materials inventory data indicates that the listing of 

“unalloyed” thorium was apparently an artifact of the site’s calculation of how much actual 

“pure” thorium made up the inventory of Mg-Th being processed. This was verified by 

comparing a sample of historic KCP inventory values from the 1970s, obtained and cleared by 

KCP, with those in the NMMSS database at DOE headquarters. Recorded values matched from 

both inventory ledgers. Other than Mg-Th, thorium being used at KCP was historically in gram 

quantities and of a laboratory scale, was handled under hoods, and did not present an exposure 

potential. SC&A recommends that this issue be closed by the WG.

Issue 17 – D&D activities: The WG tasked SC&A with clarifying a possible path forward on 

what data or information would inform a NIOSH analysis of whether KCP workers in historic 

decontamination and decommissioning (D&D) activities would have been either already 

monitored or whose potential exposure would be bound by proposed NIOSH methods at KCP. 

NIOSH would then determine its approach and propose same to the WG.

SC&A Assessment: As with Matrix Issue 7 (radioactive waste management), it is clear from the 

March 2015 onsite interviews with former workers ([Worker 5], [Worker 2], and ([Worker 3]),

that at KCP, laborers had a substantial role in cleaning up floors, walls, and equipment, whether 

on a day-to-day basis, or in periodic room cleanups. A clear distinction was made between 

“laborers” who handled cleaning duties and various crafts responsible for moving, maintaining, 

and operating equipment, such as lathes. Some laborers wore external dosimeters (it was said to 

be mandatory in Mg-Th areas), but none of the former laborers interviewed indicated any routine 

bioassay. While the “KCP machine repair” was responsible for taking equipment apart, the 

laborers were responsible for cleaning the internal parts of that equipment ([Worker 2], 

[Worker 4], and [Worker 5]). It is clear that non-bioassayed laborers had a substantial D&D 

role at KCP for the periodic room and equipment cleanups that took place at the plant; it is not 

clear whether their exposure potential was the same as the DU and Mg-Th machinists, 

themselves.

In terms of a “path-forward,” SC&A recommends that NIOSH review the relative exposure 

potential of the custodial/laborers who routinely cleaned contaminated equipment and areas, as 

compared with machinists who did the machining of DU and Mg-Th, with an objective of 

informing the WG as to whether these exposures are comparable (or for the former, lower) and 

can therefore be adequately bounded using available monitoring data.

Issue 18 – Accidents, Incidents, and Fires in Worker’s Record: In its original issue item, 

SC&A observed that the ER only referenced two radiological incidents of note—the 1987 
Memo – Response to KCP Matrix Issues 3 SC&A – April 20, 2015

NOTICE: This memo has been reviewed for Privacy Act information and has been cleared for distribution.

However, this report is pre-decisional and has not been reviewed by the Advisory Board on Radiation and Worker 

Health for factual accuracy or applicability within the requirements of 42 CFR 82.

erbium tritide contamination and the 1989 Pm-147 contamination—and that this did not 

adequately account for KCP’s lengthy operational history. SC&A later noted to the WG that a 

number of records were found during the October 2014 visit that identified accidents, incidents, 

and fires at KCP. While weekly activity reports were only located for a narrow range of years 

(mid-1960s, early 1970s), a folder titled “Radiation Incidents” was found that documents 

incidents from 1963–1975. None of these incidents were significant in terms of exposure to 

large numbers of workers and all could be bounded by NIOSH’s dose reconstruction approach. 

At its January 20, 2015, meeting, the WG tasked SC&A (and requested NIOSH) to continue 

searching for additional incident reporting during its March 2015 KCP site visit.

SC&A Assessment: An additional onsite data capture was conducted at KCP during March 2–5, 

2015. Some additional incident-related reports were found, including an unusual occurrence file 

that provided evaluations of KCP incidents related to lost sealed radioactive sources (e.g., 

Pm-147 in 1988), radioactive contamination on parts returned to KCP from the field (1989), and 

low-level contamination on uranium components received from Oak Ridge (1989). Also 

included was an employee concern package related to potentially unmonitored x-ray exposures 

in 1989. All of these were evaluated and closed in the documentation reviewed with the 

exception of the employee concern.

2

While the three KCP site data captures have realized a more complete compendium of site 

radiological incidents, it cannot be said to be necessarily complete given what appear to be some 

gaps in time and a heavy concentration of reporting in the late-1980s. However, none of the 

incidents reviewed to date indicate exposures that were not adequately addressed by the site or 

potential exposures or ones that would not be feasible to dose reconstruct.

As a further measure to add to this information, SC&A has scheduled another review of 

classified documents and notes at the DOE Germantown facility in May 2015, as a means to 

investigate incidents involving classified operations raised during WG meetings and past 

interviews. Any relevant findings from this visit will be conveyed to the WG.

Issue 20 – Tritium: The WG requested that NIOSH update its white paper with new 

information on organic tritium source term, with both NIOSH and SC&A to continue looking for 

any new documentation regarding tritium operations at KCP during the next site visit.

As indicated at the January 20, 2015, WG meeting, SC&A has reviewed NIOSH’s white paper 

(NIOSH 2015) and found that it had more fully characterized historic tritium operations at KCP. 

The documents referenced and included in the SRDB represent the extent of what was identified 

from KCP record holdings during data capture visits in 2014–2015.

 

2

SC&A reviewed this concern and found that a radiation survey conducted by KCP found resulting 

radiation levels to be very low, but not “as-low-as-reasonably-achievable,” necessitating actions including repair to 

x-ray cabinet doors and the purchase of survey instruments to be maintained in the rooms of concern. While 

workers in the adjacent room were unmonitored, it remains unclear whether this room was an unrestricted area not 

requiring any badging. While no closure documentation was found, it appears that this concern was investigated by 

KCP and actions taken.
Memo – Response to KCP Matrix Issues 4 SC&A – April 20, 2015

NOTICE: This memo has been reviewed for Privacy Act information and has been cleared for distribution.

However, this report is pre-decisional and has not been reviewed by the Advisory Board on Radiation and Worker 

Health for factual accuracy or applicability within the requirements of 42 CFR 82.

Essentially, as described in the NIOSH white paper, two discrete operations involving tritium 

(including one involving Ni-63) were identified: (1) the use of tritiated luminescent paint to fill 

engraved markings on “Hi-Lo” switch plates during 1963–1968; and (2) manufacturing of 

tritium monitors during 1959–1975. The Ni-63 operation involved small-scale chemical plating

for the Tritium Air Monitor, Bendix/Sandia Model T446.

For the first tritium application (“Hi-Lo” switch plates), NIOSH found KCP workers were 

applying tritiated phosphors containing 40 mCi of tritium to switch plates to be used in 

commercial dials. Based on a known volume of switch plates processed in 1965 (based on a 

1966 trip report summary) and data collected from 110 contamination swipes taken from 330 

switch plates in 1965, an upper 95th percentile distribution value of 16,900 dpm/100 cm2is 

assumed for the bounding contamination level. Assuming three switch plates handled per day, 

all of the surface contamination transferred to the worker’s skin, and all of the transferred skin 

contamination absorbed, leads to a bounding daily intake of 101,400 dpm (1,690 Bq). This 

translates to a bounding dose of 3.04E-6 rem/day or 0.7 mrem/year (250 work days).

For the second tritium application, NIOSH and SC&A found evidence that tritium-in-air 

instruments and tritium-in-urine monitors designed by Sandia were fabricated at KCP from 1959 

through the early 1970s. As noted by NIOSH in its white paper, this involved the use of tritiated 

water as a calibration standard, and plated Ni-63 as a component of one of the tritium-in-air 

models. From Bendix and Sandia documentation, it was determined that KCP procured tritiated 

water in unopened bottles from Sandia and installed them in instrument kits beginning in 1959. 

Starting in 1964, tritiated water was received in gallon bottles and rebottled into smaller 400-ml 

bottles for use in the kits. With the advent of liquid scintillation methods in the early 1970s, the 

market for these tritium urinalysis instruments presumably ended and there is no further record 

of this operation. Assuming that all bottles were handled under a fume hood (as were the initial 

bottles procured in 1959), NIOSH calculates that a bounding exposure can be based on an 

assumed 1-ml tritiated water spill occurring for each bottle-filling activity, which, when spread 

over an assumed 100 cm2area of the impervious floor of a fume hood, would lead to a 

removable hydration layer that would retain 0.1 ml of tritiated water, which equates to 56,000 

dpm. Assuming that this contamination is completely transferred to the skin of a KCP laboratory 

technician and is completely absorbed into the blood stream each day leads to a worker dose of 

1.68E-6 rem/day or 0.4 mrem/year (250 work days).

For the Ni-63 plating operation, which was ancillary to the tritium bottling activity, NIOSH 

judged the potential worker exposure to be negligibly small based on its low-energy beta 

radiation, the small activity applied to each precipitator plate (about 0.5 uCi), and radiological 

controls imposed, which included a radiological hazard analysis and procedural precautions 

(primarily waste management and spill response).

SC&A Assessment: SC&A finds that the lack of specific information regarding exposure 

source terms, operational conditions, and workplace measurements, coupled with the lack of any 

bioassay data, over the operational years in question makes it difficult to bound potential worker 

doses without NIOSH’s reliance on these broad assumptions, no matter how logical and 

scientifically founded. It is also not clear which KCP workers were involved in these operations
Memo – Response to KCP Matrix Issues 5 SC&A – April 20, 2015

NOTICE: This memo has been reviewed for Privacy Act information and has been cleared for distribution.

However, this report is pre-decisional and has not been reviewed by the Advisory Board on Radiation and Worker 

Health for factual accuracy or applicability within the requirements of 42 CFR 82.

and how (or whether), and to whom NIOSH intends to assign doses from potential tritium 

exposure during the years in question.

Additional data capture and onsite interviews conducted during March 2–5, 2015, coupled with 

further review of available documentation on the SRDB, have not identified any new or more 

complete information regarding the two tritium operations in question. SC&A recommends that 

the WG consider the dose reconstruction bounding approach identified in NIOSH’s white paper 

in the context of the minimal potential exposures involved, the relatively small scope of these

operations, and the conservative dose bounding approaches proposed. While some key 

parameters relevant to dose reconstruction are lacking, the source term involved equates to 

potential maximum doses at the fractional mrem level. This perspective notwithstanding, 

NIOSH should inform the WG on whether (and how) it intends to dose reconstruct for these 

historic tritium exposures, with appropriate sample dose reconstructions.

REFERENCES

[Worker 1]. Former KCP worker; interview conducted at KCP on March 3, 2015. SRDB 

pending.

[Worker 2]. Former KCP worker; interview conducted at KCP on March 3, 2015. SRDB 

pending.

[Worker 3]. Former KCP worker; interview conducted at KCP on March 3, 2015. SRDB 

pending.

[Worker 4]. Former KCP worker; interview conducted at KCP on March 3, 2015. SRDB

pending.

NIOSH 2015. Tritium and Ni-63 at the Kansas City Plant, White Paper, Rev. 0, Robert Morris, 

Billy P. Smith and Pat McCloskey, National Institute for Occupational Safety and Health, 

January 13, 2015.

[Worker 5]. Former KCP worker; interview conducted at KCP on March 3, 2015. SRDB 

pending.