ML20104A002

NRR E-mail Capture - Comanche Peak Unit 2 - Request for Additional Information - Proposed Alternative to ASME OM Code for Deferral of Snubber Testing (SNB-1) and Visual Examinations (SNB-2)

ML20104A002
Person / Time
Site:	Comanche Peak
Issue date:	04/11/2020
From:	Dennis Galvin NRC/NRR/DORL/LPL4
To:	Hicks J TEX Operations Company
References
L 2020-LLR-0060
Download: ML20104A002 (4)

Text

From: Galvin, Dennis Sent: Saturday, April 11, 2020 12:46 PM To: Jack Hicks (Jack.Hicks@luminant.com)

Cc: Barnette, James

Subject:

Comanche Peak Unit 2 - Request for Additional Information - Proposed Alternative to ASME OM Code for Deferral of Snubber Testing (SNB-1) and Visual Examinations (SNB-2) (EPID: L 2020-LLR-0060)

Attachments: L-2020-LLR-0060 Comanche Peak Relief Request - RAIs Snubber Alternative 2020-04-11.pdf Mr. Hicks, By letter dated April 10, 2020 (Agencywide Documents and Access Management System (ADAMS) Accession No. ML20101K726), Vistra Operations Company LLC (the licensee) requested Nuclear Regulatory Commission (NRC) approval of proposed alternatives to American Society Of Mechanical Engineers (ASME) Code for Operation and Maintenance of Nuclear Power Plants (OM CODE) in accordance with 10 CFR 50.55a(z)(2), Hardship without a compensating increase in quality and safety. The proposed alternative is to defer the testing of snubbers (SNB-1) and the visual examination of snubbers (SNB-2) from the Comanche Peak Nuclear Power Plant (Comanche Peak) Unit 2 spring 2020 refueling outage (2RF18) to the Comanche Peak Unit 2 fall 2021 refueling outage (2RF19) due to COVID-19 issues.

The NRC staff has determined that additional information is needed to complete its review. The requests for additional information (RAIs) were transmitted to the licensee in draft form on April 11, 2020. The licensee informed the NRC staff on April 11, 2020, that no clarification call was needed and would provide responses to the RAls by April 13, 2020. The NRC staff agreed with this date.

If you have any questions, please contact me at (301) 415-6256 or Dennis.Galvin@nrc.gov.

Respectfully, Dennis Galvin Project Manager U.S Nuclear Regulatory Commission Office of Nuclear Reactor Regulation Division of Operating Reactor Licensing Licensing Project Branch 4 301-415-6256 Docket No. 50-446

Hearing Identifier: NRR_DRMA Email Number: 524 Mail Envelope Properties (MN2PR09MB52733731E506AAC113094B4BFBDF0)

Subject:

Comanche Peak Unit 2 - Request for Additional Information - Proposed Alternative to ASME OM Code for Deferral of Snubber Testing (SNB-1) and Visual Examinations (SNB-2)

(EPID: L 2020-LLR-0060)

Sent Date: 4/11/2020 12:45:37 PM Received Date: 4/11/2020 12:45:00 PM From: Galvin, Dennis Created By: Dennis.Galvin@nrc.gov Recipients:

"Barnette, James" <James.Barnette@luminant.com>

Tracking Status: None "Jack Hicks (Jack.Hicks@luminant.com)" <Jack.Hicks@luminant.com>

Tracking Status: None Post Office: MN2PR09MB5273.namprd09.prod.outlook.com Files Size Date & Time MESSAGE 1518 4/11/2020 12:45:00 PM L-2020-LLR-0060 Comanche Peak Relief Request - RAIs Snubber Alternative 2020-04-11.pdf 72438 Options Priority: Normal Return Notification: No Reply Requested: No Sensitivity: Normal Expiration Date:

REQUEST FOR ADDITIONAL INFORMATION PROPOSED ALTERNATIVE TO AMERICAN SOCIETY OF MECHANICAL ENGINEERS (ASME) CODE FOR OPERATION AND MAINTENANCE OF NUCLEAR POWER PLANTS (OM CODE), FOR DEFERRAL OF SNUBBER TESTING (SNB-1) AND VISUAL EXAMINATIONS (SNB-2) IN ACCORDANCE WITH 10 CFR 50.55A(Z)(2)

VISTRA OPERATIONS COMPANY LLC COMANCHE PEAK UNIT 2 DOCKET NO. 50-446 By letter dated April 10, 2020 (Agencywide Documents and Access Management System (ADAMS) Accession No. ML20101K726), Vistra Operations Company LLC (the licensee) requested Nuclear Regulatory Commission (NRC) approval of proposed alternatives to American Society Of Mechanical Engineers (ASME) Code for Operation and Maintenance of Nuclear Power Plants (OM CODE) in accordance with 10 CFR 50.55a(z)(2), Hardship without a compensating increase in quality and safety. The proposed alternative is to defer the testing of snubbers (SNB-1) and the visual examination of snubbers (SNB-2) from the Comanche Peak Nuclear Power Plant (Comanche Peak) Unit 2 spring 2020 refueling outage (2RF18) to the Comanche Peak Unit 2 fall 2021 refueling outage (2RF19) due to COVID-19 issues.

To complete its review, the NRC staff requests the following additional information.

Request SNB-1

1. In Section 4 (first paragraph), the licensee indicates that it is requesting authorization of a one-time Snubber Program interval extension from the spring 2020 refueling outage (RFO) to the fall 2021 RFO. Elsewhere in the submittal, the licensee refers to this request as relief for elimination of snubber testing. The staff does not consider this request to relate to relief under 10 CFR 50.55a(f)(5) nor elimination of snubber testing. Please clarify that this request relates to a hardship alternative under 10 CFR 50.55a(z)(2) for a one-time extension of the Snubber Program testing interval until the next RFO in the fall of 2021.

2. In Table 1, the licensee provides a list of 39 specific snubbers planned for testing this RFO for which the one-time Snubber Program test interval extension is being requested. Section 5 (second paragraph) discusses three snubber test failures during the RFO in the fall of 2018. It appears that only one of these snubbers that failed its test (RC-2-135-402-C41K) is among the plant snubbers listed in Table 1. Please confirm that Snubber RC-2-135-402-C41K is the only snubber that failed its test to be among those being requested for the test interval extension.

3. Section 5 indicates that Snubber RC-2-135-402-C41K experienced a high temperature condition because of its installed location. For high temperature degradation (such as dry grease) for snubbers, the NRC issued Information Notice (IN) 2015-09, Mechanical Dynamic Restraints (Snubbers) Lubricant Degradation Not Identified due to Insufficient Service Life Monitoring. Please describe the basis for reasonable assurance that Snubber RC-2-135-402-C41K will be capable of performing its safety function until the fall of 2021, including the operating experience discussed in IN 2015-09.

4. In Section 5, the licensee states that Snubber CS-2-RB-061-704-1 had a test failure in the past. The licensee did not provide any details about the test plan extension for Snubber CS RB-061-704-1 per the applicable ASME OM Code, Subsection ISTD, paragraphs ISTD-5312 and ISTD-5412, as a result of this test failure.

5. In Section 4, the licensee states that it groups the program snubbers into two Defined Test Plan Groups (DTPGs) as the 10% test plan and the 37-sample plan. Please indicate the appropriate plan for each snubber listed in Table 1.

6. In Section 4, the licensee indicates that some of the snubbers are steam generator snubbers. Please indicate the steam generators snubbers that are listed in Table 1 and describe their performance history separately.

7. Table 1 indicates the Service Life Expiration date for each snubber within the scope of this request. Please indicate in which RFO these Service Life Expiration dates were established per ASME OM Code, Subsection ISTD, paragraph ISTD-6200.

Request SNB-2

1. In Section 5 (first paragraph), the licensee indicates that it is requesting one-time relief associated with performing snubber visual examinations pursuant to 10 CFR 50.55a(z)(2) to the next refueling outage (RFO). Elsewhere in its request, the licensee refers to an elimination or relief from snubber visual examinations during this RFO. Please clarify that this request relates to a hardship alternative under 10 CFR 50.55a(z)(2) for a one-time extension of the Snubber Program examination interval until the next RFO in the fall of 2021.

2. Table 1 lists a significant number of snubbers to be included in this alternative request. What is the total number of snubbers included in this request?

3. In Section 5 (second paragraph), the licensee reports that 1140 visual examinations have been performed since 2011 with only 3 visual examination issues. The licensee states that only one snubber (RC-2-135-402-C41K) failed its subsequent testing while the other two snubbers met their test acceptance criteria. Please identify the two snubbers that failed their visual examination but met their test acceptance criteria.

4. Request SNB-1 indicates that Snubber RC-2-135-402-C41K is located in a high temperature area. Please describe the basis for reasonable assurance that Snubber RC-2-135-402-C41K will be capable of performing its safety function until the fall of 2021.

5. Table 1 lists four large Paul Monroe Hydraulic Snubbers. Please summarize the recent history of the visual examinations for those snubbers.

6. Table 1 indicates the Service Life Expiration date for each snubber within the scope of this request. Please indicate in which RFO these Service Life Expiration dates were established per ASME OM Code, Subsection ISTD, paragraph ISTD-6200.

7. Note 1 at the end of Table 1 refers to Previous visual examination Spring 2011 - All Satisfactory. To which snubbers in Table 1 does this note refer?