National Institute for Occupational Safety and Health

SEC-00236 Metals and Controls Corporation

NIOSH Update on Petitioner Concerns

Christine Corwin

Health Physicist

Teleconference of the Metals and Controls Work Group

January 9, 2020
Summary of Petitioner Concerns Issues

 Summary of current responses to SC&A Review of the NIOSH Response 

Paper: “Metals and Controls Corp. SEC-00236 Petitioner Concerns”

0 Findings 0 Observations
Petitioner Concern 1

 NIOSH has failed to satisfy these fundamental regulatory requirements:

– Source term characterization is incomplete; 

– Incomplete knowledge of the nature, frequency, and duration of jobs 

performed in intimate contact with the source term; 

– A complete absence of any measurements or monitoring of the 

workers who are covered by this petition; 

– And no comparable population with measurements or monitoring 

data that can be relied on as a surrogate for the class in question
Petitioner Concern 1 (Continued)

 SC&A Review

– SC&A found that NIOSH presented data that can form the basis of 

estimating doses to M&C workers during the residual period. SC&A 

disagrees with some the parameters and assumptions which NIOSH 

used to implement its approach but these would be site profile 

(technical basis document) issues.

 Action Needed

– None
Petitioner Concern 2

 The petitioner noted that the 1996 drain characterization survey in the 

interiors of Bldg. 10 and Bldg. 4 only analyzed the sediment and soil 

samples for isotopic uranium. Therefore, we can never know for sure what 

the thorium concentrations might have been.

 SC&A Review

– NIOSH has enough information to estimate worker exposures to 

residual thorium-232 contamination.

 Action Needed

– None
Petitioner Concern 3

 By the time the drain survey was conducted in 1995, there had been close 

to 30 years of disturbances of the drain lines during the residual period, 

they were snaked numerous times, and some of the most plugged 

sections had been removed entirely. Therefore, there is no guarantee that 

the levels documented in the drain survey represent the maximum levels 

ever present, and to which the M&C maintenance workers would have 

been exposed. 

 SC&A Review

– NIOSH addressed this concern by adopting the 95th percentile value of 

the pipe contamination data, rather than the geometric mean, as the 

basis of exposures of M&C maintenance workers. SC&A concurred 

with this strategy. 
Petitioner Concern 3 (Continued)

 Action Needed

– None
Petitioner Concern 4

 The gross alpha screening analysis methodology that was used for the 

1994-1995 comprehensive characterization surveys, for the majority of 

subsurface soils other than the drain survey area, was biased low at 

concentrations above the 30 pCi/gram cleanup standard. 

 SC&A Review

– SC&A’s review of the 1994–1995 survey methodology and results did 

not find any evidence of bias that would affect the conservativeness of 

our exposure model. 

 Action Needed

– None
Petitioner Concern 5

 The petitioner cited remarks made by the Chair of the M&C work group, at 

the 126th Meeting of the Advisory Board on December 13, 2018, referring 

to contaminated soil and other debris removed (by railcars) during the 

1992-1996 decommissioning activities from a site that had been released 

for unrestricted use. The petitioner stated that this residual 

contamination exposed M&C maintenance workers to unknown and 

unknowable levels of exposure.

 SC&A Review

– The NIOSH response concerning the contamination surveys that were 

performed prior to the removal of the soil and other debris, the 

changing release criteria, and the use of more comprehensive 

investigative methods, fully responds to the petitioner’s concerns.
Petitioner Concern 5 (continued)

 Action Needed

– None
Petitioner Concern 6

 Concerning the incomplete knowledge of the nature, frequency, and 

duration of jobs performed; the degree of confidence that the NIOSH and 

SC&A technical experts place in the one-month duration estimate for all 

intrusive activities, both subsurface and in overhead areas, seems overly 

confident. 

 SC&A Review

– SC&A believes that NIOSH can arrive at a bounding, plausible 

estimate.

 Action Needed

– None
Petitioner Concern 7

 There is a complete absence of any measurements or monitoring of the 

workers who are the subject of the petition. NIOSH has relied on 

measurement and monitoring data for several surrogate populations that 

are not comparable to the typical M&C maintenance worker in the class 

covered by the petition. The surrogate classes proposed by NIOSH do not 

adequately characterize the maximum radiation dose to any member of 

the class covered by the petition.
Petitioner Concern 7 (continued)

 SC&A Response

– SC&A concludes that NIOSH is able to construct plausible, bounding 

scenarios to assess the exposures of M&C workers during the residual 

period. 

 Action Needed

– None
Petitioner Concern 8

 NIOSH has failed to take a broader, and more accurate, view of the typical 

M&C maintenance worker. The measurement and monitoring data from 

the 1960s, 1980s and the 1990s for radiation workers and D&D workers, 

on which NIOSH has relied for their dose reconstruction modeling, are not 

suitable to estimate the bounding dose for the class of M&C maintenance 

workers.

 SC&A Review

– SC&A found that NIOSH presented data and methods that constitute a 

sound basis for assessing worker exposures, including those of workers 

engaged in maintenance and remediation during the residual period. 
Petitioner Concern 8 (Continued)

 Action Needed

– None
Petitioner Concern 9

 An M&C Health Physicist expressed concerns that NIOSH was using 

measurement and monitoring data collected for D&D workers during the 

1990s decommissioning project as a surrogate for the types of exposures 

received by M&C Maintenance Workers during the residual period for 

estimating a bounding dose. The M&C Health Physicist also claimed that 

members of the Advisory Board stated that it is virtually impossible to 

identify every conceivable exposure scenario that the M&C maintenance 

workers were exposed to. 
Petitioner Concern 9 (continued)

 SC&A Review

– presented data and methods that constitute a sound basis for 

assessing worker exposures, including those of workers engaged in 

maintenance and remediation during the residual period at M&C.

– NIOSH will augment the dose reconstructions with any additional 

information based on the workers’ experience and recollections that is 

furnished by claimants.

 Action Needed

– None