ML21298A222

HI-STORM Amd. 18 Pre-submittal Slides

ML21298A222
Person / Time
Issue date:	10/25/2021
From:	Holtec
To:	Office of Nuclear Material Safety and Safeguards
C JACOBS NRC/NMSS/DFM/STLB 3014156825
References
Download: ML21298A222 (8)

Text

www.holtec.com Amendment to Incorporate Topical Report For Allowance of Candidate Heat Load Patterns - HI-STORM 100

Background

Holtec submitted the request for approval of a topical report Report outlines a methodology for the thermal evaluation of heat load patterns in the MPC Approved in September 2021 Holtec now plans on submitting an amendment to incorporate this topical report www.holtec.com l Page 2

Proposed CoC Changes -

App A/C www.holtec.com l Page 3

Proposed CoC Changes -

App A/C www.holtec.com l Page 4

Proposed CoC Changes -

App B/D www.holtec.com l Page 5

Proposed FSAR Updates Added a section for Topical Report Implementation Covers impacts of the Topical Report on:

Structural FSAR structural analyses use calculated temperatures If heat load patterns developed under topical report calculate increased temperatures, these temperatures should be reviewed under provisions of 72.48 to determine if change to structural analysis is acceptable without NRC approval Shielding - FQTs in CoC apply regardless of heat load pattern Change Control www.holtec.com l Page 6

Proposed FSAR Updates -

Change Control Topical Report SER - Limitation 4.2 describes the model reviewed for the scope of the topical report as invariant FSAR and FSAR thermal model are allowed to be modified under 10CFR72.48 Therefore, change can be made to FSAR without NRC approval, if it meets the 10 CFR 72.48 criteria Then the topical report methodology can be applied Additional restriction applied that the results from the revised model must be demonstrated to have a lower PCT than those in the topical report when run for identical heat loads If this criterion is met, then the topical report can be applied to updated FSAR model www.holtec.com l Page 7

Summary Candidate Heat Load Pattern Will the heat load Obtain NRC Amendment Can the canister model pattern be used in a or utilize a different be added to the FSAR canister model identical No No canister model under 72.48?

to that identified in the TR?

Yes Yes Update FSAR in accordance with 72.48 process Does the updated model calculate equal to or lower PCT than the TR model when run for the same heat load No pattern?

Evaluate the candidate heat load pattern using Yes the approved TR methodology Obtain NRC Are the temperature No Can the structural Amendment or results from the TR evaluations in the FSAR utilize a different bounded by those used be modified under No heat load pattern Are all TR acceptance in the FSAR structural 72.48?

criteria met? analysis No Yes Yes Document 72.48 Yes screening/evaluation and Document thermal update FSAR if necessary heat load pattern in technical report Site choses fuel to meet allowable heat load pattern, confirming that fuel also meets all other applicable CoC requirements (for example, shielding) www.holtec.com l Page 8