ML21130A601

Correction of Proposed Alternative IST-RR-8 to the Requirements of the ASME OM Code for the Residual Heat Removal Pump 1B-B

ML21130A601
Person / Time
Site:	Watts Bar
Issue date:	05/13/2021
From:	Kimberly Green Plant Licensing Branch II
To:	Jim Barstow Tennessee Valley Authority
Green K
References
EPID L-2020-LLR-0116
Download: ML21130A601 (5)

Text

May 13, 2021 Mr. James Barstow Vice President, Nuclear Regulatory Affairs and Support Services Tennessee Valley Authority 1101 Market Street, LP 4A-C Chattanooga, TN 37402-2801

SUBJECT:

WATTS BAR NUCLEAR PLANT, UNIT 1 - CORRECTION OF PROPOSED ALTERNATIVE IST-RR-8 TO THE REQUIREMENTS OF THE ASME OM CODE FOR THE RESIDUAL HEAT REMOVAL PUMP 1B-B (EPID L-2020-LLR-0116)

Dear Mr. Barstow:

On April 29, 2021, the U.S. Nuclear Regulatory Commission (NRC) authorized Alternative Request IST-RR-8 (Agencywide Documents Access and Management System (ADAMS)

Accession No. ML21110A037) for Watts Bar Nuclear Plant (Watts Bar), Unit 1. The authorization allowed for use of an alternative to American Society of Mechanical Engineers (ASME) Operation and Maintenance of Nuclear Power Plants (OM Code) required inservice test program (IST) comprehensive pump testing for the residual heat removal pump 1B-B until the end of the U1R17 refueling outage, which is scheduled to be completed by November 27, 2021.

The purpose of this letter is to issue a correction to the NRC staffs safety evaluation (SE) that is attached as an enclosure to IST-RR-8. Specifically, Section 3.1 of the SE states, in part, The ASME OM Code of record for Watts Bar, Unit 1, is the 2004 Edition through 2006 Addenda.

The third 10-year interval for the Watts Bar, Unit 1, IST Program started on October 22, 2015 and is scheduled to end on October 21, 2025. However, the third 10-year interval for the Watts Bar, Unit 1, IST Program began on October 19, 2016, and is scheduled to end on October 18, 2026. The NRC staff is issuing a revised Page 2 of its SE (enclosed) to correctly state the current IST Program interval for Watts Bar, Unit 1. The NRC staff determined that the correction to the SE page does not change the staffs previous conclusion.

J. Barstow If you have any questions regarding this matter, please contact me at (301) 415-1627.

Sincerely,

/RA/

Kimberly J. Green, Senior Project Manager Plant Licensing Branch II-2 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket No. 50-390

Enclosure:

Corrected Safety Evaluation Page 2 cc: Listserv

ENCLOSURE WATTS BAR NUCLEAR PLANT, UNIT 1 DOCKET NO. 50-390 CORRECTED SAFETY EVALUATION PAGE 2

10 CFR 50.55a(a)(1)(iv), to the extent practical within the limitations of design, geometry, and materials of construction of the components.

The regulations in 10 CFR 50.55a(z) state, in part, that alternatives to the requirements of 10 CFR 50.55a(f) may be used, when authorized by the NRC, if the licensee demonstrates (1) the proposed alternative would provide an acceptable level of quality and safety; or (2) compliance with the specified requirements would result in hardship or unusual difficulty without a compensating increase in the level of quality and safety.

3.0 TECHNICAL EVALUATION

3.1 Licensees Alternative Request IST-RR-8 The licensee requested an alternative to the requirements of the ASME OM Code for IST frequency for a pump in the alert range.

ISTB-6200(a), Alert Range, states that if the measured test parameter values fall within the alert range of Table ISTB-5121-1, Table ISTB-5221-1, Table 5321-1, or Table ISTB-5321-2, as applicable, the frequency of testing specified in ISTB-3400 shall be doubled until the cause of the deviation is determined and the condition is corrected.

The licensee has requested to use the proposed alternative described below for RHR pump 1B-B. The pump is ASME Boiler and Pressure Vessel Code (BPV Code),Section III, Class 2, and is classified as a Group A pump.

The licensee requested that the proposed alternative request be authorized through the completion of the U1R17 refueling outage, which is currently scheduled to be completed by November 27, 2021.

The ASME OM Code of record for Watts Bar, Unit 1, is the 2004 Edition through 2006 Addenda.

The third 10-year interval for the Watts Bar, Unit 1, IST Program started on October 19, 2016 and is scheduled to end on October 18, 2026.

Reason for Request

The licensee states that the RHR pump 1B-B is a safety-related, vertical, single stage centrifugal motor-driven pump, with the motor installed on a supporting head, which is supported by the stuffing box extension/casing. The pump impeller is mounted to the motor shaft and the RHR pump flow is limited to 3000 gallons per minute (gpm) per pump during two pump operation (normal cooldown mode).

The RHR system is designed to perform post-accident safety-related functions, normal safety-related functions, and normal non-safety-related functions. The post-accident safety functions of the RHR system are to (1) operate as an emergency core cooling system (ECCS) subsystem, (2) operate as a subsystem of the containment spray system (CSS), and (3) provide a flow path to the reactor coolant system (RCS) from the spent fuel pool cooling and cleaning system (SFPCS) during flood mode when the reactor vessel head is removed.

The RHR pump 1B-B CPT is performed during refueling outages (18-month cycle) with the reactor head removed from the reactor vessel, allowing flow to be directed into the reactor cavity in order to achieve the required CPT flow rate. On May 21, 2020, during the Watts Bar,

ML21130A601 OFFICE NRR/DORL/LPL2-2/PM NRR/DORL/LPL2-2/LA NRR/DORL/LPL2-2/BC NAME LHaeg RButler DWrona DATE 5/10/2021 5/11/2021 5/12/2021 OFFICE NRR/DORL/LPL2-2/PM NAME KGreen DATE 5/13/2021