NL-11-2123, Units 1 & 2, IST Program - Relief Request Proposed Alternative in Accordance with 10 CFR 50-55.a (a)(3)(ii), RR-P-3, Version 2
| ML113010346 | |
| Person / Time | |
|---|---|
| Site: | Farley  |
| Issue date: | 10/28/2011 |
| From: | Ajluni M Southern Nuclear Operating Co |
| To: | Office of Nuclear Reactor Regulation, Document Control Desk |
| References | |
| NL-11-2123 | |
| Download: ML113010346 (6) | |
Text
Mark J. Ajluni, P.E.
Southern Nuclear Nuclear Licensing Director Operating Company, Inc.
40 Inverness Center Parkway Post Offi ce Box 1295 Birrn ingharn, Alabarna 35201 Tel 205.992.7673 Fax 205.992.7885 October 2B, 2011 SOUTHERN COMPANY Docket Nos.: 50-34B NL-11-2123 50-364 U. S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, D. C. 20555-0001 Joseph M. Farley Nuclear Plant - Units 1 and 2 1ST Program - Relief Request Proposed Alternative in Accordance with 10 CFR 50.55a(a)(3)(ii)
RR-P-3, Version 2 Ladies and Gentlemen:
By letter dated August 14, 2007, Southern Nuclear Operating Company (SNC) submitted relief request RR-P-3 as part of the Fourth Ten-Year Intervallnservice Testing (1ST) Program Update (ML0722B0494). In a letter dated July 1, 200B,
SNC received a request for additional information regarding RR-P-3 (MLOB1690B45). By letter dated July 14, 200B, SNC responded and made a commitment to test motor driven auxiliary feedwater (MDAFW) pumps to determine if greater than 50 gpm flow could be achieved and to provide the results to the NRC (MLOB1970245). On August 6, 200B, the NRC sent Farley Nuclear Plant (FNP) a Safety Evaluation Report (SER) concerning the FNP Fourth 10-Year Interval 1ST Program (MLOB2050002). In this SER, the NRC granted FNP interim relief until July 1, 2010 for pump relief request RR-P-3. On September B, 2009, SNC submitted to the NRC the results of the evaluation (ML092520159) which concluded that the need for relief request RR-P-3 was still valid. As a result, SNC requested authorization of RR-P-3 for the entire 10-Year Interval.
During follow-up conversations between the NRC and SNC, it was requested that SI\\JC update the proposed RR-P-3 with the latest information as applicable and formally resubmit to the NRC for review and approval. SNC hereby submits, pursuant to 10 CFR 50.55a(a)(3)(II), the 1ST Program Relief Request RR-P-3, Version 2 for NRC review and approval.
U. S. Nuclear Regulatory Commission NL-11-2123 Page 2 This letter contains no NRC commitments. If you have any questions, please contact Jack Stringfellow at (205) 992-7037.
Sincerely,
~~r M. J. Ajluni Nuclear Licensing Director MJAlRMJllac
Enclosure:
1ST Program - Relief Request Proposed Alternative RR-P-3, Version 2 cc:
Southern Nuclear Operating Company Mr. S. E. Kuczynski, Chairman, President & CEO Mr. D. G. Bost, Chief Nuclear Officer Mr. T. A. Lynch, Vice President - Farley Ms. P. M. Marino, Vice President - Engineering Ms. J. R. Robertson - Engineering Programs RTYPE: CFA04.054 U. S. Nuclear Regulatory Commission Mr. V. M. McCree, Regional Administrator Mr. V. Sreenivas, NRR Project Manager - Farley Mr. E. L. Crowe, Senior Resident Inspector - Farley
Joseph M. Farley Nuclear Plant - Units 1 and 2 1ST Program - Relief Request Proposed Alternative in Accordance with 10 CFR 50.55a(a)(3)(ii)
RR-P-3, Version 2 Enclosure 1ST Program - Relief Request Proposed Alternative RR-P-3, Version 2
Enclosure 1ST Program - Relief Request Proposed Alternative RR-P-3, Version 2 PLANT/UNIT:
INTERVAL:
COMPONENTS AFFECTED:
CODE EDITION AND ADDENDA:
REQUIREMENTS:
REASON FOR REQUEST:
Joseph M. Farley Nuclear Plant / Units 1 and 2.
4th 1 O-year Interval beginning December 1, 2007 and ending November 30,2017.
01 N23P001A, 8 (Horizontal Centrifugal Motor Driven Auxiliary Feedwater (MDAFW) Pumps) Group A 02N23P001A, 8 (Horizontal Centrifugal Motor Driven Auxiliary Feedwater (MDAFW) Pumps) Group A ASME OM Code-2001 Edition with Addenda through OMb-2003 IST8-5121 requires a quarterly Group A pump 1ST with the pump operating at a specified reference point. The test parameters shown in Table IST8-3000-1 shall be determined and recorded. Table IST8 3000-1 identifies flow rate as a required test parameter. (This relief request is not applicable to biennial Comprehensive or Preservice pump 1ST.)
IST8-5121 requires a quarterly Group A pump 1ST by varying flow path resistance until either the differential pressure or flow rate equals the corresponding reference value, or by use of a fixed resistance flow path. The only system valve(s) with flow throttling capability is located in the injection line to the steam generators. Use of these injection line(s) is not practical during normal operation, because the injection of cold water into the hot steam generators results in a significant thermal shock of the injection nozzles. This repeated thermal cycling could result in feedwater nozzle cracking.
In addition to the potential thermal cycling effects described above, FNP requested the NSSS vendor (Westinghouse) to evaluate other impacts of injecting AFW into the steam generators during normal plant operation. The NSSS vendor evaluation identified that injection of AFW into the steam generators in plant operating Mode 1 could result in 1) a positive reactivity addition induced by increased, cooler combined AFW and Main Feedwater (rvlFW) flow, and 2) a possible steam generator level excursion due to added feedwater flow downstream of the flow venturis. The NSSS vendor indicated that the combined effects of increased feedwater flow and decreased feedwater temperature in Mode 1 would actually put the unit in an unanalyzed condition.
The NSSS vendor evaluation stated that if MDAFW pump flow to the steam generators was to be performed during normal unit operation, it must be performed at reactor power levels between 15% and 97.5%.
Since quarterly 1ST is typically performed with the Unit operating at El - 1
Enclosure 1ST Program - Relief Request Proposed Alternative RR-P-3, Version 2 PROPOSED AL TERNATIVES AND BASIS:
100% power, reducing power to :5 97.5% would increase the workload on Operations crews and the potential for error-likely situations and unanticipated transients (e.g., Unit Trip).
Each MDAFW pump is provided with a 4" return line to the Condensate Storage Tank (CST). However, the line downstream of the first isolation valve is ANSI 831.10, Class III Non-Nuclear, and the piping and supports were not designed and installed to be used for routine full-flow testing of the pump. FNP previously attempted to utilize the 4" return line for MDAFW pump 1ST and experienced significant piping vibration that was considered detrimental to component integrity. In fact, testing on the return line resulted in vibration levels which caused weld cracking and leaks of some small diameter << 1" NPS) vent and drain connections. SNC engineering subsequently recommended complete re-design of the return line piping and support system if 1ST was to be continued in this manner. Redesign and modification of these 4" return lines would result in a significant hardship with minimal increase in the level of quality and safety, since each MDAFW pump is tested every refueling outage at the maximum required accident flow rate during the Comprehensive Pump Test (CPT).
Alternative 1 - Current Through No Later Than 12131/2012 The quarterly MDAFW pump Group A 1ST will be performed utilizing the 2" fixed resistance minimum flow line with measurement of differential pressure and vibration only.
In conjunction with the above 1ST, FNP will also conduct quarterly 1ST using alternative flow instrumentation to determine the feasibility of measuring flow through the 2" minimum flow line and the repeatability of the 1ST data. The 2" minimum flow line is not equipped with any flow throttling capability but is provided with a fixed resistance flow orifice.
Therefore, FNP expects the flow rate to be essentially constant from test to test.
Alternative 2 - No Later Than 0110112013 Through 11/01/2017 FNP will evaluate the data from the quarterly ISTs and determine if flow rate measurement is practical. If practical, then subsequent quarterly 1ST will be performed on the 2" minimum flow line with measurement of flow rate, differential pressure and vibration which meets the OM Code requirements, and SNC will withdraw this relief request. However, if not practical, FNP will continue performing the quarterly 1ST utilizing the 2" fixed resistance minimum flow line with measurement of differential pressure and vibration only, and RR-P-3 will remain part of the 1ST Program.
BASIS The MDAFW pumps are categorized as OM Code Group A pumps only EI-2
DURATION:
PRECEDENTS:
REFERENCES:
STATUS:
Enclosure 1ST Program - Relief Request Proposed Alternative RR-P-3, Version 2 because they are utilized to provide feedwater to the steam generators when the Reactor power level is not sufficient to provide adequate steam for the turbine driven main feedwater pumps. Therefore, the pumps are only run for relatively short periods of time when the unit is shutting down or starting up. As a result, these pumps are not expected to experience significant mechanical degradation for many years of plant operation.
Either of the above-described alternative quarterly 1ST methods, in conjunction with the full flow rate CPT each refueling outage, provides adequate assurance of pump operational readiness and will also detect any gross mechanical degradation.
Therefore, based on SNC's conclusion that compliance with the Code requirements results in a hardship without a compensating increase in the level of quality and safety, this proposed alternative should be granted pursuant to 10 CFR 50.55a(a)(3)(ii).
4th 1ST Interval, December 1, 2007 through November 30,2017.
This alternative is similar to NRC approved FNP 3rd Interval Relief Request RR-P-5 that was based on the ASME OM Code-1990 Edition, no addenda. This 4th Interval request for relief is based on the ASME OM Code-2001 Edition with Addenda through OMb-2003.
NRC Safety Evaluation dated October 29, 1998 - TAC Nos. M99186 and M99187.
Interim relief was granted via SER dated August 6, 2008 until July 1, 2010. SNC submitted a response to the interim relief on September 8, 2009 (ML092520159).
El - 3