Memo – KCP – Outstanding Issues 1 SC&A – July 2, 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: July 2, 2015 

TO: KCP Work Group 

FROM: Joe Fitzgerald, SC&A

SUBJECT: Status of KCP Outstanding Issues

With the Kansas City Plant (KCP) Work Group (WG) meeting scheduled for July 16–17, 2015, 

SC&A believes it is useful to recap our understanding of the status of outstanding Special 

Exposure Cohort (SEC) issues, along with issue-specific comments that may serve to facilitate 

discussion at the WG meeting. 

To date, the following issue dispositions have taken place or are still pending:1

Issue 1: Data Completeness, Legibility, and Accuracy

In a June 11, 2015, memorandum to the WG, NIOSH provided its approach for validating the 

existing internal and external dose electronic database by comparison with raw records. It was 

noted that “NIOSH plans to extract data from DOE-supplied dose records in the 691 NOCTS 

claims currently available” and “compare this raw data to that in the database previously used for 

the coworker model.”

SC&A Status/Comments: Assuming that the “DOE-supplied dose records” provided as part of 

the NIOSH/OCAS Claims Tracking System (NOCTS) contain the original source or raw records 

for both external and internal doses, SC&A believes this would be an appropriate means by 

which the electronic database can be validated through comparison sampling. (It would be 

useful for NIOSH to identify to the WG what degree of sampling it intends to do). 

Issue 7: Radioactive Waste 

In an April 14, 2015, memorandum to the WG, SC&A concluded that these activities were being 

performed by a worker category (laborers) distinct from uranium or thorium workers who, based 

on interviews with affected workers, were not routinely badged or bioassayed. 

In a subsequent review of the KCP database, NIOSH found that 2 of the 4 identified laborers 

(from a larger population) who handled radwaste had bioassays in their records. NIOSH 

indicated in its June 11 memorandum that it will use these data “where available” to reconstruct 

doses. It is noted that, “NIOSH has reviewed safety procedures that span the years 1951–1975,” 

and that radiological control measures evinced in those procedures provide “supporting evidence 

that the methods in the ER plausibly bound exposures during this period.” NIOSH further 

reviews SC&A’s 2007 report, A Focused Review of Operations and Thorium Exposures of the 

 

1

 Note that this represents SC&A’s summary of the issue and its disposition; for specific wording, see the 

cited NIOSH documents. 
Memo – KCP – Outstanding Issues 2 SC&A – July 2, 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.

Dow Chemical Madison Plant, and concludes that it is “not likely that KCP waste handlers were 

exposed to a higher concentration [of airborne Th-232] on a 2,000-hour time-weighted-average 

(TWA) basis.”

 

SC&A Status/Comments: What NIOSH does not indicate is how these data compare with that 

of KCP uranium workers, and whether it would be claimant favorable to assign the uranium 

worker data distribution, given that there are only two data points for this worker category (i.e., 

laborers who handled radwaste). With such a small dataset, it is not clear that enough data exist 

for a coworker dose distribution for radwaste handlers. The same question would apply for the 

radwaste handlers for Mg-Th wastes.

Issues 11/12: Neutron Dose

NIOSH notes that SC&A’s April 21, 2015, memorandum to the WG concluded that “NIOSH’s 

use of a neutron dose of 0.154 rem/year for KCP workers that may have been exposed to 

neutrons is reasonable and claimant favorable,” and further notes that “SC&A considers the 

present KCP SEC neutron dose-related issues addressed and the issues have been closed by the 

Advisory Board.”

SC&A Status/Comments: SC&A concurs with NIOSH’s statement, and recommends final WG 

closure.

Issue 13: Mg-Th

SC&A issued its white paper response on May 12, 2015, and is awaiting a NIOSH response. A 

teleconference was held between NIOSH, two Advisory Board members, and SC&A on June 29, 

2015, to clarify how best to approach performing sample dose reconstructions to validate 

previously proposed NIOSH approaches for reconstructing Mg-Th exposures at KCP. For MgTh, one scenario discussed is to dose reconstruct a hypothetical worker who machined Mg-Th 

from 1963–1979, which encompasses the time periods and locations in question.

Issue 15: Thorium Oxide Operations

NIOSH notes that SC&A (in its April memorandum) recommends closure and NIOSH agrees.

SC&A Status/Comments: Closure recommended.

Issue 17: D&D Activities

Similar to Issue 7 for radwaste handlers, SC&A concluded that these activities were being 

performed by a worker category distinct from uranium or thorium workers, who were not 

necessarily monitored (based on interviews), and that these workers (laborers) would have been 

potentially exposed. Again, NIOSH notes that it had identified 2 out of 4 laborers as having 

internal monitoring records and “will use that data where appropriate to reconstruct doses.” It is 

further noted that the ER acknowledges and addresses the fact that various worker categories had 

“varying exposure potential,” and that furthermore, an extensive procedural review confirmed 
Memo – KCP – Outstanding Issues 3 SC&A – July 2, 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.

that KCP implemented a “robust area and personal monitoring program.” Similarly, a review of 

SC&A’s 2007 report, A Focused Review of Operations and Thorium Exposures of the Dow 

Chemical Madison Plant, concludes that it is “not likely that KCP waste handlers were exposed 

to a higher concentration [of airborne Th-232] on a 2,000-hour time-weighted-average (TWA) 

basis.”

SC&A Status/Comments: NIOSH again references the two bioassay data points identified for 

laborers and goes on to make a programmatic case that KCP had a robust contamination control 

program and that the monitoring data for uranium workers validate the bounding methods of the 

ER. However, with only two data points for laborers and some question as to whether both of 

these particular laborers conducted D&D, it is not clear how these bounding data would be 

applied for them. Assuming they were cleaning rooms where uranium machining had taken 

place (such as those in Department 20), it remains unclear why any such unmonitored workers 

conducting these activities in uranium-contaminated areas would not have the bounding uranium 

worker dose distribution applied for the D&D time period in question. (NIOSH’s case regarding 

thorium is more persuasive; SC&A agrees that these workers were unlikely to be exposed to 

residual thorium at concentrations in excess of 1.5 E-11 μCi/ml). 

Issue 18: Incidents

SC&A recommends closure. A review of classified records containing incident data did not 

uncover any additional reports worth including. With no new incidents to investigate or any new 

evidence that exposure incidents would make a difference in dose reconstructability, this issue 

should be closed.

Issue 20: Tritium

In Rev. 01 to its white paper, Tritium and Nickel-63 at the Kansas City Plant (May 7, 2015), 

NIOSH has added more details regarding the operational history of tritium use at KCP and has 

added a last page that identifies an upper bound dose estimation in mrem/year for each identified 

tritium and Ni-63 operation at KCP.

SC&A Status/Comments: While the more specific treatment of bounding doses for each 

operation is helpful, NIOSH does not explain how that dose will be used in dose reconstruction, 

i.e., to whom it will be applied [only workers identified as handling tritium, all workers in certain 

parts of KCP (e.g., laboratory), or all workers at KCP during those specific timeframes]? A 

teleconference was held on June 29, 2015, to clarify possible avenues for performing sample 

dose reconstructions to validate that these bounding doses can be applied to a defined worker 

category. For Ni-63, SC&A concurs with NIOSH’s bounding analysis showing no external 

exposure potential and a bounding annual dose of 0.02 mrem/year, which the WG may consider 

a negligible exposure.