ML15007A161

Alternative Request During the Fourth Ten-Year Inservice Inspection Interval

ML15007A161
Person / Time
Site:	Summer
Issue date:	01/09/2015
From:	Robert Pascarelli Plant Licensing Branch II
To:	Gatlin T South Carolina Electric & Gas Co
Williams S
References
TAC MF5457
Download: ML15007A161 (8)

Text

UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. 20555-0001 January 9, 2015 Mr. Thomas D. Gatlin Vice President, Nuclear Operations South Carolina Electric & Gas Company Virgil C. Summer Nuclear Station

• Post Office Box 88, Mail Code 800 Jenkinsville, SC 29065

SUBJECT:

VIRGIL C. SUMMER NUCLEAR STATION, UNIT 1 -ALTERNATIVE REQUEST DURING THE FOURTH TEN-YEAR INSERVICE INSPECTION INTERVAL (TAC NO. MF5457)

Dear Mr. Gatlin:

By letter dated December 18, 2014, South Carolina Electric & Gas Company (SCE&G, the licensee), submitted an alternative request to the U.S. Nuclear Regulatory Commission (NRC).

The licensee proposed to apply the methodology previously covered under Generic Letter 89-04, Position 9 for quarterly Group A inservice testing of Charging/Safety Injection pumps.

The application was submitted pursuant to Section 50.55a (z)(1) of Title 10 of the Code of Federal Regulations ( 10 CFR), which requires the applicant to demonstrate that the proposed alternative would provide an acceptable level of quality and safety.

The NRC staff has reviewed the subject request and concludes, as set forth in the enclosed safety evaluation, that SCE&G has adequately addressed all of the regulatory requirements set forth in 50.55a (z)(1 ), and therefore authorizes the proposed alternative.

T. Gatlin If you have any questions, please contact the Project Manager, Shawn Williams, at 301.-415-1009 or via e-mail at Shawn.Williams@nrc.gov.

Sincerely, Robert J. Pascarelli, Chief Plant Licensing Branch 11-1 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket No. 50-395

Enclosure:

Safety Evaluation cc w/encl: Distribution via Listserv

UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. 20555-0001 SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION ALTERNATIVE REQUEST RR-4-06 FOURTH 10-YEAR INSERVICE INSPECTION PROGRAM INTERVAL SOUTH CAROLINA ELECTRIC & GAS COMPANY SOUTH CAROLINA PUBLIC SERVICE AUTHORITY VIRGIL C. SUMMER NUCLEAR STATION, UNIT 1 DOCKET NO. 50-395

1.0 INTRODUCTION

By letter dated December 18, 2014 (Agencywide Documents Access and Management System (ADAMS) Accession No. ML14356A560), South Carolina Electric & Gas Company (SCE&G),

the licensee, submitted an alternative request RR-4-06 to the U.S. Nuclear Regulatory Commission (NRC). The licensee requested an alternative test plan in lieu of certain inservice testing (1ST) requirements of the 2004 Edition through 2006 Addenda of the American Society of Mechanical Engineers (ASME) Code for Operation and Maintenance of Nuclear Power Plants (OM Code) for the 1ST program at Virgil C. Summer Nuclear Station (VCSNS) Unit 1 during the fourth 10-year 1ST program interval, which began on January 1, 2014, and is currently scheduled to conclude on December 31, 2023.

The application was submitted pursuant to Section 50.55a(z)(1) of Title 10 of the Code of Federal Regulations (1 0 CFR), which requires the applicant to demonstrate that the proposed alternative would provide an acceptable level of quality and safety.

2.0 REGULATORY EVALUATION

10 CFR 50.55a(f), "lnservice Testing Requirements," requires, in part, that 1ST of certain ASME Code Class 1, 2, and 3 components must meet the requirements of the ASME OM Code and applicable addenda, except where alternatives have been authorized pursuant to paragraphs (z)( 1) or (z)(2).

In proposing alternatives, a licensee must demonstrate that the proposed alternatives provide an acceptable level of quality and safety (1 0 CFR 50.55a(z)(1 )) or compliance would result in hardship or unusual difficulty Without a compensating increase in the level of quality and safety (10 CFR 50.55a(z)(2)).

Enclosure

Based on the above, and subject to the following technical evaluation, the NRC staff finds that regulatory authority exists for the licensee to request and the Commission to authorize the alternative requested by the licensee.

3.0 TECHNICAL EVALUATION

3.1.1 Licensee's Alternative Request RR-4-06 ASME OM Code Requirements:

ISTB-3000, "General Testing Requirements," states, in part, the parameters to be measured during preservice and inservice testing are specified in Table ISTB-3000-1.

Table ISTB-3000-1, "lnservice Test Parameters," specifies, in part, that Flow Rate (Q) is required to be measured during Group A pump preservice and inservice testing.

ISTB-351 O(a), "Accuracy," states, in part, instrument accuracy shall be within the limits of Taple ISTB-3510-1. If a parameter is determined by analytical methods instead of measurement, then the determination shall meet the parameter accuracy requirement of Table .

ISTB-3510-1.

ISTB-3550, "Flow Rate," states, When measuring flow rate, a rate or quantity meter shall be installed in the pump test circuit. If a meter does not indicate the flow rate directly, the record shall include the method used to reduce the data. Internal recirculated flow is not required to be measured. External recirculated flow is not required to be measured if it is not practical to isolate, has a fixed resistance, and has been evaluated by the Owner to not have substantial effect on the results of the test.

ISTB-5100, "Centrifugal Pumps (Except Vertical Line Shaft Centrifugal Pumps)," Part A, "Duration of Tests," (1) states, For the Group A test and the comprehensive test, after pump conditions are as stable as the system permits, each pump shall be run at least 2 minutes. At the end of this time at least one measurement or determination of each of the quantities required by Table ISTB-3000-1 shall be made and recorded.

ISTB-5121(c), "Group A Test Procedure," states, Where itis not practical to vary system resistance, flow rate and pressure shall be determined and compared to their respective reference values.

ISTB-5121 (e), "Group A Test Procedure," states in part, All deviations from the reference values shall be compared with the ranges of Table ISTB-5121-1 and corrective action taken as specified in ISTB-6200.

Alternative testing is requested for the following pumps:

Table 1 Pump ID Function Group Class XPP0043A Charging/Safety Injection Pump A 2 XPP0043B Charging/Safety Injection Pump A 2 XPP0043C Charging/Safety Injection Pump A 2 The *licensee states in part:

Reason for Request

VCSNS's Charging/Safety Injection (SI) System was constructed without installed flow measurement instrumentation in the Charging/SI System minimum-flow recirculation lines.

During the previous two test intervals Charging/SI Pump inservice testing was conducted in accordance with Generic Letter (GL) 89-04 Position 9.

Efforts were undertaken to measure flow through the recirculation lines using ultrasonic flow meters prior to the new interval. Strap-on ultrasonic flow meters have been used during the first 12 months of the new interval to measure recirculation flow during Charging/SI Pump quarterly

• Group A testing. The required instrument repeatability established in ASME OM Code Table ISTB-351 0-1 could not be achieved. During field use, flow rate variations of up to 6 percent and higher from average were noted. Inaccuracies associated with clamp-on ultrasonic flow measurement devices were the subject of NRC Information Notice (IN) 95-08, "Inaccurate Data Obtained with Clamp-on Ultrasonic Flow Measurement Instruments."

Relief from the requirement to measure recirculation line flow during Charging/SI Pump Group A testing is requested based on the lack of consistency in data measurement using the ultrasonic meters and lack of installed instrumentation.

Proposed Alternative VCSNS has historically performed a quarterly surveillance test without measuring the recirculation line flow rate as provided for in GL 89-04, Position 9. VCSNS has attempted to measure flow with ultrasonic flow meters but has not been successful. Through this relief request, VCSNS proposes to use the previous method as identified in GL 89-04 as an alternative method for meeting the surveillance requirement, therefore, maintaining an acceptable level of quality and safety. Performing inservice testing using a non-instrumented recirculation line was previously found acceptable by the NRC in GL 89-04, Position 9, "Pump Testing using Minimum-flow Return Line With or Without Flow Measuring Devices," when an instrumented flow path was available during refueling for measuring flow at a substantial flow rate.

Pump flow is measured during a comprehensive test each refueling outage with the minimum-flow line isolated. Pump performance is then compared to Design Basis Accident analysis requirements.

The Group A pump quarterly test of the Charging/SI Pumps will be performed in accordance with GL 89-04, Position 9, measuring pump differential pressure and vibration. The Charging/SI Pump orifices are large differential pressure orifices, with backpressure having minimal effect on orifice performance.

- Using the provisions of this request as an alternative to the requirements of ISTB-3000, Table ISTB-3000-1, ISTB-51 OO(a), and ISTB-5121 provides a reasonable alternative to the Code requirements based on the determination that the proposed alternative will provide adequate indication of pump performance, permit detection of component degradation, and continue to provide an acceptable level of quality and safety. Therefore, pursuant to 10 CFR 50.55a(z)(1 ),

VCSNS requests approval of this alternative to the specific ISTB requirements identified in this request.

SCE&G will implement the alternative requirements during the fourth 10-year In service Testing interval at VCSNS, Unit 1, which began January 1, 2014, and ends December 31, 2023.

3.1.2 NRC Staff Evaluation ASME OM Code 2004 Edition through 2006 Addenda Section ISTB-5221 (c), "Group A Test Procedure," states: Where system resistance cannot be varied, flow rate and pressure shall be determined and compared to their respective reference values. ASME OM Code Section ISTB-3300(e)(2), "Reference Values," states: Reference values shall be established within

+/-20% of pump design for the Group A and Group B tests, if practicable. If not practicable, the reference point flow shall pe established at the highest practical flow rate. ASME OM Code Section ISTB-351 O(a), "Accuracy," states in part: Instrument accuracy shall be within the limits of Table ISTB-351 0-1. If a parameter is determined by analytical methods instead of measurement, then the determination shall meet the parameter accuracy requirement of Table ISTB-3510-1 (e.g., flow rate determination shall be accurate to within +/-2% of actual). ASME OM Code Section ISTB-3550, "Flow Rate," states in part: When measuring flow rate, a rate or quantity meter shall be installed in the pump test circuit.

Charging/Safety Injection pumps XPP0043A, XPP0043B, and XPP0043C are defined as Group A pumps per the ASME OM Code. During normal plant operation, at least one charging pump is continuously in service. The second pump is a non-running pump on the inactive loop and the third, if available, is designated as a spare and its breaker(s) are racked out. The non-running pumps may be tested during power operation via the minimum flow bypass lines.

During the first 12 months of the new 1ST interval, the licensee has attempted to meet the Code requirement of measuring flow set at a prescribed reference value as directed by Section ISTB-5121, "Group A Test Procedure" by using external strap-on ultrasonic flow instrumentation on the minimum flow bypass lines for the standby pumps. However, due to the design of the minimum flow bypass lines and the limitations of the ultrasonic flow instrumentation, difficulty in achieving the accuracy requirements of ISTB-351 O(a) were encountered. The licensee has proposed an alternative to quarterly test using the minimLJm flow path lines without installed flow rate instrumentation. Measurements will include differential pressure across the pump and vibration in accordance with ASME OM Code-2004 through 2006 Addenda Section ISTB-5121.

The NRC staff has reviewed the licensee's proposed alternative and has determined that the testing is consistent with the guidance in NUREG-1482, Revision 2, Section 5.9, "Pump Testing Using Minimum Flow Return Lines With or Without Flow Measuring Devices," and GL 89-04, "Guidance On Developing Acceptable lnservice Testing Programs," Position 9. The proposed alternative provides an acceptable level of quality and safety.

4.0 CONCLUSION

As set forth above, the NRC staff finds that the proposed alternative described in alternative request RR-4-06 provides an acceptable level of quality and safety for pumps listed in Table 1.

Accordingly, the NRC staff concludes that the licensee has adequately addressed all of the regulatory requirements set forth in 10 CFR 50.55a(z)(1 ). Therefore, the NRC staff authorizes the proposed alternative in request RR-4-06 for the fourth 1ST interval at VCSNS which began on January 1, 2014, and is currently scheduled to end on December 31, 2023.

All other ASME OM Code requirements for which relief was not specifically requested and approved in the subject requests for relief remain applicable.

Principle Contributor: Michael Farna11, NRR Dated: January 9, 2015

T. Gatlin If you have any questions, please contact the Project Manager, Shawn Williams, at 301-415-1009 or via e-mail at Shawn.Williams@nrc.gov.

Sincerely,

/RAJ Robert J. Pascarelli, Chief Plant Licensing Branch 11-1 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket No. 50-395

Enclosure:

Safety Evaluation cc w/encl: Distribution via Listserv DISTRIBUTION:

Public LPL2-1 R/F . MFarnan, NRR RidsAcrs_AcnwMaiiCTR Resource RidsNrrLASFigueroa Resource RidsNrrDoriDpr Resource RidsRgn2MaiiCenter Resource RidsNrrPMSummer Resource RidsNrrDeEpnb Resource

. ADAMS Accession No.: ML15007A161 *By E-mail OFFICE LPLII-1/PM LPLII-1/LA DE/EPNB/BC LPLII-1/BC LPLII-1/PM NAME SWilliams SFigueroa DAIIey* RPascarelli SWilliams DATE 01/08/15 01/08/15 01/08/15 01/08/15 01/09/15 OFFICIAL RECORD COPY