ML24221A138
| ML24221A138 | |
| Person / Time | |
|---|---|
| Site: | 07109302 |
| Issue date: | 08/21/2024 |
| From: | Bernie White Storage and Transportation Licensing Branch |
| To: | Roman C Division of Fuel Management |
| References | |
| EPID L-2024-LRM-0080 | |
| Download: ML24221A138 (1) | |
Text
UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. 20555-0001 MEMORANDUM TO: Cinthya Román, Deputy Director Division of Fuel Management Office of Nuclear Material Safety and Safeguards FROM:
Bernard White, Senior Project Manager Storage and Transportation Licensing Branch Division of Fuel Management Office of Nuclear Material Safety and Safeguards
SUBJECT:
SUMMARY
OF JUNE 26, 2024, MEETING WITH TN-AMERICAS LLC TO DISCUSS SHIELDING EVALUATION FOR LOW-LEVEL WASTE IN THE NUHOMS MP197HB
Background
On June 26, 2024, the U.S. Nuclear Regulatory Commission (NRC) held an open meeting between TN-Americas LLC (TN) and the NRC. TN requested the meeting to provide the NRC with an overview of a proposed shielding methodology that could be used to evaluate the package dose rates for transport of irradiated reactor vessel internals. The meeting was noticed on June 13, 2024 (Agencywide Documents Access and Management System Accession No. ML24165A118). The list of meeting attendees is provided as an Enclosure.
Discussion TN provided the NRC an overview of the Model No. NUHOMS MP197HB as it is configured to transport low-level waste. TN stated that the low-level waste contents of the certificate are limited to a maximum of 60,800 Curies of cobalt-60 or equivalent, and the specific activity of discrete components is limited to not more than 6.46 Curies of cobalt-60 per kilogram of contents. In addition, the volume of discrete components in the shipment shall be divided into 10 or more nearly equal volumes not greater than 0.1 m3. TN stated that to meet the specific activity requirement, low-level waste contents needed to cool for up to 15 years. TN provided an overview of the reactor core barrels and baffle and former assemblies and how these items would be cut to be placed inside a radioactive waste canister and secured in place using shoring.
CONTACT:
Bernard White, NMSS/DFM (301) 415-6577 August 21, 2024 Signed by White, Bernard on 08/21/24
C. Román 2
TN provided an overview of its proposed methodology for determining the dose rates for the core barrel and former and baffle assembly using existing dose rate measurements to benchmark the analyses. TN has radiation measurement survey and loading data for a number of loaded radioactive waste canisters. It provided measurement data as of March 2023 for gamma dose rates around an OS197 transfer cask. TN stated that since the OS197 transfer cask and the NUHOMS MP197HB package have different amounts of shielding, it needed to adjust the dose rate measurements to account for the additional shielding in the NUHOMS MP197HB. TN stated that it adjusted the data based on the number of half-value thicknesses in the transfer cask and package. Since the NUHOMS MP197HB package has twice as many half-value thicknesses of stainless steel and lead as the OS197 transfer cask, the measurement data was divided by two to benchmark the analyses on the NUHOMS MP197HB package.
TN then provided the model it used to determine the dose rates on the NUHOMS MP197HB package showing the realistic modeling of the contents, rather than homogenizing the contents inside the radioactive waste canister. The activation analysis assumed a typical pressurized-water reactor lifecycle. TN provided three slides of dose rate analyses around the NUHOMS MP197HB package, one for no additional decay time in March 2023, one for 1 year of additional decay time in March 2024, and the last for 2 years of additional decay time in March 2025. TN compared the survey measurements to the results of the no additional decay time dose rate calculations.
TN provided a comparison of the contents models for the existing certificate with the more realistic model used in the analyses. TN stated that using this methodology, it could transport the material offsite after 2 years of decay, instead of waiting for 15 years to meet the existing certificate limit for specific activity. The NRC asked whether TN was considering incorporating this methodology as a basis for revising the contents in its certificate of compliance. TN stated that it was considering using the methodology on a case-by-case basis for specific shipments, and if used, would be in a request for a letter authorization for a specific shipment.
Docket No. 71-9302 EPID No. L-2024-LRM-0080
Enclosure:
Meeting Attendees
ML24221A138 OFFICE NMSS/DFM NMSS/DFM NMSS/DFM/SMB NMSS/DFM NMSS/DFM NMSS/DFM NAME BWhite SFigueroa EGoldfeiz TGovan YDiaz-Sanabria BWhite DATE 8/9/2024 8/9/2024 8/15/2024 8/20/2024 8/20/2024 8/21/2024
Enclosure MEETING ATTENDEES Meeting
Title:
SUMMARY
OF JUNE 26, 2024, MEETING WITH TN-AMERICAS LLC TO DISCUSS SHIELDING EVALUATION FOR LOW-LEVEL WASTE IN THE NUHOMS MP197HB
Participants:
TN-AMERICAS LLC and the U.S. Nuclear Regulatory Commission (NRC)
Date:
June 26, 2024 NAME AFFILIATION Bernie White NRC Yoira Diaz Sanabria; NRC Eliezer Goldfeiz NRC Tekia Govan NRC Pierre Saverot NRC Philip Sewell TN-Americas LLC Don Shaw TN-Americas LLC Douglas Yates TN-Americas LLC Paulette Pettie TN-Americas LLC Vescovi Peter TN-Americas LLC Olivier Gandou TN-Americas LLC Bill Casino TN-Americas LLC Jason Heineman TN-Americas LLC