Update: Oak Ridge National Laboratory

(X-10) Work Group

Genevieve Roessler, Chair

Josie Beach

R. William Field

Loretta Valerio

141st Meeting of the Advisory Board on Radiation and 

Worker Health

August 19, 2021
Background
Exotic Radionuclides

• Due to resource overlap, NIOSH decided to 

Reserve the exotic radionuclide evaluation at 

ORNL and combine with the Y-12 83.14 effort 

once SEC-00189 was completed and 

presented.

• On August 30, 2012 NIOSH/ORAUT had a 

kick-off meeting for this combined effort

• NIOSH will update the ABRWH as we 

progress in our evaluation
Overview

 ORNL WG meeting June 30, 2021

 Relevant documents under discussion:

 ORAUT-RPRT-0090, 3/28/2018, Assessing doses from isotope 

production at ORNL from 1955-1988

 SC&A Review of ORAUT-RPRT-0090, 10/9/2018

 NIOSH Response to SC&A Review of ORAUT-RPRT-0090, 6/3/2020

 SC&A Review of NIOSH Response to SC&A Review of ORAUTRPRT-0090, 1/8/2021

 7 Findings – 3 open pending NIOSH action, 4 closed

 6 Observations – 2 open pending NIOSH action, 4 closed
Finding 1: Scope of ORAUT-RPRT-0090 

needs to be clearly defined

 NIOSH clarified that only activities of ORNL 

Isotope Division were the scope of the report

 Question involved other activities such as waste 

management, construction, and maintenance

 SC&A accepts this clarification

 WG accepts SC&A’s recommendation to close the 

finding.

 Finding 1 closed
Finding 2: Incomplete radionuclide and 

radioisotope facility inventory

 SC&A found several radionuclides missing from Table 7-2 (a listing 

of radionuclides considered in the report)

 NIOSH response: Discrepancy is due to focus of document on 

being on radioisotope production only. NIOSH will explain in next 

revision of RPRT-0090

 SC&A accepts this clarification

 WG accepts SC&A’s recommendation to close the finding

 Finding 2 closed
Finding 3: In vitro bioassay methods lack 

information about actual implementation

 Bioassay methods in ORAUT-RPRT-0090 do not discuss actual 

implementation of methods as required by DCAS-IG-006

 DCAS IG-006 was issued after ORAUT-RPRT-0090

 WG agrees that finding should remain open pending NIOSH action

 NIOSH action item: develop co-exposure model for exotic 

radionuclides and update language in ORAUT-RPRT-0090 

related to “feasibility”

 Finding 3 open
Finding 4: Feasibility of monitoring 28 

radionuclides not adequately addressed

 The approach presented in ORAUT-RPRT-0090 for the 28 

radionuclides in Table 7-6 is not sufficiently detailed

 NIOSH responded that the approach used is the source term 

approach -- an accepted procedure for bounding dose

 WG agrees that ORAUT-RPRT-0090 needs to be updated with more 

suitable wording (remove language regarding “insignificant intakes”)

 NIOSH action item: update ORAUT-RPRT-0090 with more detail 

on DR approach for the 28 listed radionuclides

 Finding 4 open
Finding 5: Iodine – 1955/1956 intakes may 

not be bound by earlier co-exposure data

 Related to Observation 6

 Radiodine production and RaLa iodine by-product release are different 

processes

 SC&A finds many issues with the NIOSH iodine exposure approach for 

unmonitored workers

 WG agrees with SC&A that the Finding remains open pending NIOSH 

action

 NIOSH action item: revise the iodine approach based on standards of 

IG-006 after SC&A concerns have been evaluated in detail

 Finding 5 open
Finding 6: Adequacy and implementation of 

in vivo bioassay program not addressed

 The discussion of the implementation of the in vivo 

program is not sufficient in ORAUT-RPRT-0090

 SC&A agreed that this issue would be addressed 

under Finding 3 and could be closed here

 WG accepts SC&A’s recommendation to close the 

finding

 Finding 6 closed
Finding 7: Unclear treatment of post-1988 

monitoring capability during abandonment, 

deactivation and D&D phases

 NIOSH clarified the scope of ORAUT-RPRT-0090 to 

only include the production operations of the 

radioisotope division

 WG accepts SC&A’s recommendation to close the 

finding

 Finding 7 closed
Observation 1: Inventory discrepancy between 

Table 7-2 and X-10 inventory spreadsheet

 NIOSH clarified discrepancy due to:

 Additional data found in logbooks

 Scope of document (see Finding 2)

 WG accepts SC&A’s recommendation to close the 

observation

 Observation 1 closed
Observation 2: Specific alpha emitting 

radionuclides need to be identified for dose 

reconstruction

 X-10 data base does not always list the specific 

radionuclide needed for DR

 NIOSH clarified that the actual bioassay cards are 

used for DR and contain this information

 WG accepts SC&A’s recommendation to close the 

observation

 Observation 2 closed
Observation 3: Trans-Plutonium 

radionuclides may need further analysis

 Assigning Am-241 as a default is a reasonable default 

assumption

 Bioassay cards with actual radionuclide are used if 

possible

 WG accepts SC&A’s recommendation to close the 

observation

 Observation 3 is closed
Observation 4: Use of gross beta or gamma 

count data could result in underestimate of dose

 Use of gross count data without knowledge of the 

counting system (e.g., calibration and counting 

efficiencies, correction factors, etc.) could lead to an 

underestimate of dose

 Specifics of the DR approach are outside the scope of 

ORAUT-RPRT-0090, but will be added to revised report

 NIOSH action item: Revise ORAUT-RPRT-0090 to 

include more DR detail

 Observation 4 remains open
Observation 5: The results in Table 7-6 

depend on the inventory used

 Spreadsheet used for X-10 data is incomplete (same 

as Observation 1)

 NIOSH will address in revision of ORAUT-RPRT0090 and next revision of TKBS-0012-5

 WG agrees with SC&A to close this observation

 Observation 5 closed
Observation 6: Additional RaLa 

information should be provided

 Subsection of Finding 5 (iodine)

 NIOSH should analyze different exposure potentials 

between commercial iodine production and RaLa process

 WG agrees to discuss this at the same time as Finding 5

 NIOSH action item: address issues of the iodine 

model as outlined in Finding 5

 Observation 6 is open
Questions/Discussion