CP-201800718, (Cpnpp), Units 1 and 2 - Supplement to Exigent License Amendment Request (LAR) 18-001, Revision to Technical Specification 3.8.4, DC Sources - Operating, Condition B

(Cpnpp), Units 1 and 2 - Supplement to Exigent License Amendment Request (LAR)18-001, Revision to Technical Specification 3.8.4, DC Sources - Operating, Condition B

ML18277A207
Person / Time
Site:	Comanche Peak
Issue date:	10/03/2018
From:	Thomas McCool Vistra Operations Company
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
CP-201800718, EPID L-2018-LLA-0238, LAR 18-001, TXX-18071
Download: ML18277A207 (4)

Text

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Luminant Thomas P. McCool Site Vice President Luminant P.O. Box 1002 6322 North FM 56 Glen Rose, TX 76043 o 254.897.6042 CP-201800718 TXX-18071 U.S. Nuclear Regulatory Commission Ref 10 CFR 50.90 ATIN: Document Control Desk 10 CFR 50.91(a)(6)

Washington, DC 20555-0001 10 CFR 50.91(b) 10/3/2018

SUBJECT:

Comanche Peak Nuclear Power Plant (CPNPP) Unit 1 and Unit 2 Docket Nos. 50-445 and 50-446 Supplement to Exigent License Amendment Request (LAR)18-001, Revision to Technical Specification 3.8.4, "DC Sources - Operating," Condition B (EPID L-2018-LLA-0238)

Reference 1. LetterTXX-18010 from Thomas P. McCool to the NRC "Submittal of Exigent License Amendment Request (LAR) 18~001, Revision to Technical Specification 3.8.4, "DC Sources - Operating,"

Condition B, dated September 5, 2018 (ML18250A186)

2. Letter TXX-18064 from Thomas P. McCool to the NRC "Response to Request for Additional Information regarding Submittal of Exigent License Amendment Request (LAR)18-001, Revision to Technical Specification 3.8.4, "DC Sources- Operating," Condition B, dated September 20, 2018 (ML18267A059)

Dear Sir or Madam:

Vistra Operations Company LLC ("Vistra OpCo") hereby submits a Supplement to License Amendment Request (LAR)18-001 requested in Reference 1. On October 2, 2018, as a result of a discussion between the NRC (Margaret O'Banion) and Vistra OpCo (Carl Corbin) it was agreed that a Supplement to LAR 18-001 would be provided. The purpose of this Supplement is to inclu~e Comanche Peak Nuclear Power Pla.nt Unit 2 in LAR 18-001. Specifically, Regulatory Commitment 57644411 in Attachment 2 of Reference 2 identifies conditions for Unit 2. of this letter provides an updated No Significant Hazards Consideration to include the conditions related to Unit 2. Attachment 1 of this letter replaces the No Significant Hazards provided in Section 4.3 of the Enclosure to Reference 1.

There are no changes to Regulatory Commitment 5644411 provided in Attachment 2 of Reference 2. There are D/

no new commitments in this letter. ;4 0 pJtf-

TXX-18071 Page 2 of 2 In accordance with 10CFR50.91(b), Vistra OpCo is providing the State ofTexas with a copy of this response to the request for additional information.

Should you have any questions, please contact Carl B. Corbin at (254) 897-0121.

I state under penalty of perjury that the foregoing is true and correct.

Executed on October 3, 2018.

Sincerely, Thom,-:;//6 No Significant Hazards Consideration for License Amendment Request (LAR)18-001 c- Kriss Kennedy, Region IV Mark Haire, Region IV Margaret Watford O'Banion, NRR Resident Inspectors, Comanche Peak Mr. Robert Free Environmental Monitoring & Emergency Response Manager Texas Department of State Health Services Mail Code 1986 P. 0. Box 149347 Austin TX, 78714-9347 to TXX-18071 Page 1 of 2 No Significant Hazards Consideration Determination for License Amendment Request (LAR)18-001 Vistra OpCo has evaluated whether or not a significant hazards consideration is involved with the proposed amendment by focusing on the three standards set forth in 10 CFR 50.92, "Issuance of amendment," as discussed below:

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1. Do the proposed changes involve a significant increase in the probability or consequences of an accident previously evaluated?

Response: No The proposed changes add provisions to increase the COMPLETION TIME (CT) from two hours to eighteen hours, on a one-time basis for Comanche Peak Nuclear Power Plant Class 1E Batteries BT1 ED2 and BT1 ED4. This one-time increase will only be used once per battery during Unit 1 Cycle 20 (not at the same time). An additional REQUIRED ACTION, new Note, and associated COMPLETION TIME is specified when batteries BT1 ED2 and BT1 ED4, associated with the plant Class 1 E Direct Current (DG) electrical power subsystem, are declared inoperable to replace a jumpered cell. Regulatory Commitment 5644411 includes conditions (preventive measures) for Unit 1 and Unit 2 .to reduce site risk for the planned replacement of cell 27 in battery BT1 ED2 and cell 41 in battery BT1 ED4. The proposed changes do not physically alter any plant structures, systems, or components, and are not accident initiators: therefore, there is no effect on the probability of accidents previously evaluated. As part of the single failure design feature, loss of any one DC electrical power subsystem does not prevent the minimum safety function from being performed. Also, the proposed changes do not affect the type or amounts of

• radionuclides release following an accident, or affect the initiation and duration of their release.

Therefore, the consequences of accidents previously evaluated, which rely on the safety related Class 1E battery to mitigate, are not significantly. increased.

Therefore, the proposed change does not involve a significant increase in the probability or consequences of an accident previously evaluated.

2. Do the proposed changes create the pos~ibility of a riew or different kind of accident from any accident previously evaluated?

Response: No The proposed changes do not involve a change in design, configuration, or method of operation of the plant. The proposed changes will not alter the manner in which equipment is operated, nor will the functional demands on credited equipment be changed. The proposed changes do not impact the interaction of any systems whose failure or malfunction can initiate an accident There are no identified redundant components affected by these changes and thus there are no new common cause failures or any existing common cause failures.that are affected by extending the CT. The proposed changes do not create any new failure modes.

Therefore, the proposed change does not create the possibility of a new or different kind of accident from any previously evaluated.

3. Do the proposed changes involve a significant reduction in a margin of safety?

Response: No The proposed changes are based upon a determJnistic evaluation. This evaluation is supplemented by risk information.

to TXX-18071 Page 2 of 2 The deterministic evaluation concluded with one inoperable battery associated with the Class 1E

.DC electrical power subsystem, the redundant OPERABLE Class 1E DC electrical power subsystems will be able to perform the safety function as described in the accident analysis.

Supplemental risk information supporting this license amendment request concluded that the additional REQUIRED ACTION, new Note, associated COMPLETION TIME have a negligible impact on overall plant risk and is consistent with the NRC Safety Goal Policy statement and the thresholds in Regulatory Guide (RG) 1.174, "An Approach for Using Probabilistic Risk Assessment in Risk-Informed Decisions on Plant-Specific Changes to the Licensing Basis," and RG 1.177, "An Approach for Plant-Specific, Risk-Informed Decisionmaking: Technical Specifications."

• The deterministic evaluation, supplemental risk information, and Regulatory Commitment 5644411 (conditions for Unit 1 and Unit 2) provide assbrance that the plant Class 1E DC electrical power subsystem will be able to perform its design function with a longer COMPLETION TIME for inoperable batteries BT1 ED2 and BT1 ED4 during Unit 1 Cycle 20, and risk is not significantly impacted by the change.

Therefore, the proposed change does not involve a significant reduction in a margin of safety.

Based on the above evaluations, Vistra OpCo concludes that the propose amendment presents no significant hazards consideration under the standards set forth in 10 CFR 50.92(c) and, accordingly, a finding of "no significant hazards consideration" is justified.