ML24191A064

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TVA Pre-Submittal Conference Presentation for Proposed LAR Regarding a Revision to Sequoyah Fuel Handling Accident Analysis, Deletion of TS 3.9.4 and Modification of TS 3.3.6 - July 16, 2024
ML24191A064
Person / Time
Site: Sequoyah  Tennessee Valley Authority icon.png
Issue date: 07/16/2024
From:
Tennessee Valley Authority
To: Perry Buckberg
NRC/NRR/DORL/LPL2-2
Buckberg, P
References
EPID L-2024-LRM-0079
Download: ML24191A064 (1)


Text

Sequoyah Nuclear Plant Pre-Submittal Conference for Proposed License Amendment Request Regarding a Revision to the Sequoyah Nuclear Plant Fuel Handling Accident Analysis, Deletion of Technical Specification 3.9.4 Containment Penetrations, and Modification of Technical Specification 3.3.6 Containment Ventilation Isolation Instrumentation July 16, 2024

Agenda

  • Introduction
  • Reason for the Proposed Changes
  • Technical Evaluation
  • Regulatory Precedent
  • Schedule for Submittal

Introduction

  • Tennessee Valley Authority (TVA) is submitting a license amendment request (LAR) for Renewed Facility Operating License Nos. DPR-77 and DPR-79 for Sequoyah Nuclear Plant (SQN), Units 1 and 2.
  • Approval is requested for three related items.

o Deletion of Technical Specification (TS) 3.9.4, Containment Penetrations.

o Revision of TS 3.3.6 Containment Ventilation Isolation Instrumentation to delete CONDITION B and SPECIFIED CONDITION (a) in Table 3.3.6-1.

o A revised Fuel Handling Accident (FHA) dose analysis.

3

Reason for the Proposed Changes 4

  • The basis for TS 3.9.4, for TS 3.3.6 CONDITION B, and for SPECIFIED CONDITION (a) in Table 3.3.6-1 was a requirement for containment penetration closure during movement of irradiated fuel assemblies within containment to ensure that a release of fission product radioactivity within containment would be restricted to within regulatory limits.

Containment closure = all potential escape paths are closed or capable of being closed.

This requirement was based on the previous FHA dose analysis.

  • The new FHA dose analysis does not credit containment penetration closure.
  • Note that SQN TS 3.9.8 remains in place to define the minimum decay time before fuel movement begins, consistent with the FHA dose analysis.
  • Deletion of the TS requirement for containment penetration closure during movement of irradiated fuel assemblies will facilitate a more efficient refueling outage schedule.

For example, this will aid in the use of ice-making equipment that is being upgraded to support compliance with TS 3.6.12 Ice Bed.

Proposed Change to SQN Technical Specification 3.9.4 5

Proposed Change to SQN Technical Specification 3.9.4 (continued) 6

Proposed Change to SQN Technical Specification 3.3.6 7

Proposed Change to SQN Technical Specification 3.3.6 (continued) 8

Technical Evaluation FHA Dose Analysis

  • Original selective implementation of alternate source term (AST) methodology for the FHA was the last time the analysis was submitted (NRC Safety Evaluation dated October 28, 2003 - ML033030206)
  • Revised analysis utilizes RG 1.183 R0 consistent with original approval
  • A table comparing FHA input parameters in the new analysis to the 2003 analysis will be provided 9

Technical Evaluation (continued)

FHA Dose Analysis (continued)

  • All inputs and assumptions from 2003 analysis remain the same except as follows:

Decay time revised from 100 hrs to 70 hrs X/Qs were updated Determined using PAVAN and ARCON96 Updated MET data from 1970s to 2004-2013 Consistent with RG 1.145, RG 1.194, and RIS 2006-04 Release point parameters will be provided Removed TPBARs from source term 10

Regulatory Precedent

  • TVA submitted a license amendment request for Watts Bar Nuclear Plant, Unit 1, to delete TS 3.9.4, "Containment Penetrations," and to modify TS 3.3.6 "Containment Vent Isolation Instrumentation," to eliminate the requirements for containment penetration closure during movement of irradiated fuel assemblies within containment, as part of selective implementation of AST for the FHA (Letter from TVA to NRC, Watts Bar Nuclear Plant Unit 1 - Application to Allow Selective Implementation of Alternate Source Term to Analyze the Dose Consequences Associated with Fuel Handling Accidents (WBN-TS-11-19), dated June 13, 2012 [ML12171A317]).
  • The NRC approved that request in a letter from the NRC to TVA, Issuance of Amendment to Allow Selective Implementation of Alternate Source Term to Analyze the Dose Consequences Associated with Fuel-Handling Accidents, dated June 19, 2013 [ML13141A564].
  • The scope of that precedent is the same as the scope of this request.

11

Schedule for Submittal

  • August 30, 2024 - Submit LAR to NRC
  • Request NRC approval by September 2025 12