ML23257A219

NRR E-mail Capture - Cooper - Final RAI LAR to Adopt TSTF-551, Revision 3

ML23257A219
Person / Time
Site:	Cooper
Issue date:	09/14/2023
From:	Thomas Wengert NRC/NRR/DORL/LPL4
To:	Dewhirst L Nebraska Public Power District (NPPD)
Wengert T
References
L-2023-LLA-0068
Download: ML23257A219 (5)

Text

From: Thomas Wengert Sent: Thursday, September 14, 2023 9:33 AM To: Dewhirst, Linda R.

Cc: Unruh, Mark E.; Jennifer Dixon-Herrity; Thomas Byrd

Subject:

Cooper - Final RAI RE: LAR to Adopt TSTF-551, Revision 3 (EPID L-2023-LLA-0068)

Attachments: Cooper - Final RAI RE TSTF-551_09142023.pdf On September 1, 2023, the U.S. Nuclear Regulatory Commission (NRC) staff sent Nebraska Public Power District (the licensee) the draft Request for Additional Information (RAI) identified below. This RAI relates to the Cooper Nuclear Station license amendment application to adopt portions of Technical Specification Task Force (TSTF) traveler, TSTF-551, Revision 3, Revise Secondary Containment Surveillance Requirements, dated October 3, 2016 (Agencywide Documents Access and Management System (ADAMS) Accession No. ML16277A226).

The licensee subsequently informed the NRC staff that the information request was understood and that no further clarification was needed. A publicly available version of this final RAI (attached with Draft removed) will be placed in the NRCs ADAMS system. As agreed, please provide a response to this RAI within 30 days of the date of this request.

From: Thomas Wengert Sent: Friday, September 1, 2023 11:17 AM To: Dewhirst, Linda R. <lrdewhi@nppd.com>

Cc: Unruh, Mark E. <m1unruh@nppd.com>; Thomas Byrd <Thomas.Byrd@nrc.gov>; Jennifer Dixon-Herrity <Jennifer.Dixon-Herrity@nrc.gov>

Subject:

Cooper - Draft RAI RE: LAR to Adopt TSTF-551, Revision 3 (EPID L-2023-LLA-0068)

By letter dated May 3, 2023, (Agencywide Documents Access and Management System (ADAMS) Accession No. ML23124A234), Nebraska Public Power District (the licensee),

submitted a license amendment request (LAR) for Cooper Nuclear Station (Cooper), requesting changes to the Cooper Technical Specifications (TSs) to adopt portions of Technical Specifications Task Force (TSTF) traveler, TSTF-551, Revision 3, Revise Secondary Containment Surveillance Requirements, dated October 3, 2016 (ADAMS Accession No. ML16277A226).

The NRC staff reviewed the submittal and determined that additional information, as described in the attached request for additional information (RAI), is required for the staff to complete its review of this application. This RAI is identified as draft at this time to confirm your understanding of the information that the NRC staff needs to complete the evaluation. If the request for information is understood, please respond to this RAI within 30 days of the date of this request.

Please contact me if you would like to set up a conference call with the NRC staff to clarify this request for additional information.

Tom Wengert Project Manager - Cooper Nuclear Station NRR/DORL/LPL4

(301) 415-4037 Hearing Identifier: NRR_DRMA Email Number: 2237 Mail Envelope Properties (PH0PR09MB74032E4E6D397AD5F7D1C88F8FF7A)

Subject:

Cooper - Final RAI RE LAR to Adopt TSTF-551, Revision 3 (EPID L-2023-LLA-0068)

Sent Date: 9/14/2023 9:33:14 AM Received Date: 9/14/2023 9:33:00 AM From: Thomas Wengert Created By: Thomas.Wengert@nrc.gov Recipients:

"Unruh, Mark E." <m1unruh@nppd.com>

Tracking Status: None "Jennifer Dixon-Herrity" <Jennifer.Dixon-Herrity@nrc.gov>

Tracking Status: None "Thomas Byrd" <Thomas.Byrd@nrc.gov>

Tracking Status: None "Dewhirst, Linda R." <lrdewhi@nppd.com>

Tracking Status: None Post Office: PH0PR09MB7403.namprd09.prod.outlook.com Files Size Date & Time MESSAGE 2467 9/14/2023 9:33:00 AM Cooper - Final RAI RE TSTF-551_09142023.pdf 142397 Options Priority: Normal Return Notification: No Reply Requested: No Sensitivity: Normal Expiration Date:

REQUEST FOR ADDITIONAL INFORMATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION LICENSE AMENDMENT REQUEST TO ADOPT TSTF-551 NEBRASKA PUBLIC POWER DISTRICT COOPER NUCLEAR STATION DOCKET NO. 05000298

Background

By letter dated May 3, 2023, (Agencywide Documents Access and Management System (ADAMS) Accession No. ML23124A234), Nebraska Public Power District (the licensee),

submitted a license amendment request (LAR) for Cooper Nuclear Station (Cooper).

Specifically, the licensee requested changes to the Cooper Technical Specifications (TSs) to adopt portions of Technical Specifications Task Force (TSTF) traveler, TSTF-551, Revision 3, Revise Secondary Containment Surveillance Requirements, dated October 3, 2016 (ADAMS Accession No. ML16277A226). The U.S. Nuclear Regulatory Commission (NRC) approved the traveler on September 21, 2017 (ADAMS Package No. ML17236A365).

Currently, Cooper TS Surveillance Requirement (SR) 3.6.4.1.1 requires the licensee to verify that secondary containment vacuum is adequate which ensures that the secondary containment boundary is sufficiently leak tight. The licensee proposes to revise SR 3.6.4.1.1 by adding the following Note based on Revision 3 of TSTF-551:

Not required to be met for 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> if analysis demonstrates one standby gas treatment (SGT) subsystem is capable of establishing the required secondary containment vacuum.

After reviewing the licensees request, the NRC staff has determined additional information is required to complete its review. The request is described below.

Regulatory Basis Title 10 of the Code of Federal Regulations (10 CFR), Section 50.36(c)(3), requires TSs to include items in the category of SRs, which are requirements relating to test, calibration, or inspection to assure that the necessary quality of systems and components is maintained, that facility operation will be within safety limits, and that the Limiting Conditions for Operation (LCOs) will be met.

Question 1 TSTF-551, Revision 3 states, in part:

For the secondary containment to be considered operable, it must have adequate leak tightness to ensure that the required vacuum can be established and maintained by a single operating SGT [standby gas treatment] subsystem.

1

As long as [an] SGT subsystem can draw the required vacuum on the secondary containment when needed (as demonstrated by SR 3.6.4.1.4 or SR 3.6.4.1.5), the secondary containment can perform its safety function.

SR 3.6.4.1.4 in NUREG-1433, Standard Technical Specifications - General Electric Plants (BWR [Boiling Water Reactor]/4), Revision 5 (ML21272A357), verifies that secondary containment can be drawn down to the necessary vacuum within a specified time period using one SGT subsystem. The Cooper facilitys TSs do not include this SR.

The NRC staff noted that the SGT system description, as described in the Cooper updated safety analysis report (USAR), assumes that both trains of SGT actuate in situations when the SGT system is required. For example, the loss of coolant accident (LOCA) design basis accident analysis in Revision 30 of the Cooper USAR in Section XIV-6.3.8.3.1.c (ML21130A101) states, in part:

Both SGT trains start upon a Group 6 PCIS [Primary Containment Isolation System] signal (assumed from time = 0 seconds to 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br />), with heater power to one train assumed to have failed. At the 1-hour point, the SGT train with the failed heater is manually secured. Table XIV-6-7 identifies the SGT flow and iodine removal efficiencies that are assumed. This includes a -1% [percent]

correction to account for SGT filter bypass.

Furthermore, Cooper USAR Table XIV-6-7, SGT System Flows and Iodine Removal Efficiencies, shows that the from time = 0 hours0 days <br />0 hours <br />0 weeks <br />0 months <br /> to 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br />, both SGT trains are running with 1492 cubic feet per minute (cfm) of flow.

Additionally, the description of the SGT system in Cooper USAR Revision 30, Section V-3.3.4 (ML21130A089) states, in part:

Upon receipt of any of the initiation signals, both fans start, all SGT system isolation valves open and each fan draws air from the isolated reactor building at a flow rate of approximately 1780 cfm. When the required negative pressure is reached, a single train of Standby Gas Treatment is capable of maintaining this negative pressure.

Based on the description in the USAR, it appears that both SGT subsystems are required to draw the adequate secondary containment vacuum.

Verify, and provide a supporting analysis, that one SGT subsystem is capable of establishing the required secondary containment vacuum, as indicated in the proposed SR 3.6.4.1.1 NOTE.

2