ML17312B211
| ML17312B211 | |
| Person / Time | |
|---|---|
| Site: | Palo Verde  |
| Issue date: | 02/04/1997 |
| From: | NRC (Affiliation Not Assigned) |
| To: | |
| Shared Package | |
| ML17312B210 | List: |
| References | |
| NUDOCS 9702070373 | |
| Download: ML17312B211 (5) | |
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UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. 20555-0001 SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION RELATED TO THE RE VEST FOR EXTENSION OF THE FIRST TEN-YEAR INTERVAL FOR THE INSERVICE TESTING PROGRAM ARIZONA PUBLIC SERVICE COMPANY PALO VERDE NUCLEAR GENERATING STATION DOCKET NOS.
STN 50-528 STN 50-529 STN 50-530
1.0 INTRODUCTION
The Code of Federal Regulations, 10 CFR 50.55a, requires that licensees maintain and update an inservice test (IST) program for their facilities.
Section 50.55a(f)(4)(ii) requires that for each ten year interval, subsequent to the initial 10 year inspection period after licensing, the updated IST program be based on the Code edition specified in 10 CFR 50.55a(b) as of 12 months prior to the beginning of the subsequent ten year IST interval.
In addition, the American Society of Mechanical Engineers (ASME) Code Section XI, Paragraph IWA-2400(c), allows IST intervals to be adjusted for up to a year from their initial completion date.
In Section 3.3.2 of NUREG-1482, "Guidelines for Inservice Testing at Nuclear Power Plants," the NRC recommended that licensees with two or more similar units at the same site consider placing the units on concurrent intervals to achieve consistency between the IST programs.
Section 50.55a(a)(3) authorizes the staff to approve alternatives to the requirements of 10 CFR 50.55a if it finds that the licensee has demonstrated that (1) the proposed alternatives provide an acceptable level of quality and
- safety, or (2) compliance would result in hardship or unusual difficulty without a compensating increase in the level of quality and safety.
In a letter dated July 11, 1996, Arizona Public Service Company (the licensee) requested that the first ten-year interval inservice testing (IST) program for Palo Verde Nuclear Generating Station (PVNGS) Units 1 and 2 be extended for 12 months and 4 months, respectively.
An extension request for Unit 3 is not required because its interval length remains in accordance with 10 CFR 50.55a and the ASME Code.
The extension is being requested for two reasons.
- First, the licensee states that its participation as a pilot plant for the approval of a risk-informed IST program has utilized resources that would have been dedicated to the second ten-year IST program interval update for all three units.
- Second, the licensee's effort to place all three units at PVNGS on concurrent intervals may not be possible without approval of an interval extension.
9702070373 970204 PDR ADQCK 05000528 6
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2.0 EVALUATION The licensee proposed a risk-informed IST program for the Palo Verde Nuclear Generating Station (PVNGS) in letters dated November 27,
- 1995, and December 20, 1995.
The program was proposed as a pilot to support staff efforts to develop generic criteria for risk-informed IST programs in the industry.
In a letter dated March 15, 1996, the NRC requested additional information (RAI) on the proposed PVNGS risk-informed IST program.
guestion G-1 of the staff's RAI requested the licensee to provide the status of the PVNGS update to the second ten-year interval IST program.
The licensee's response to question G-l, provided in a letter dated June 7,
- 1996, stated that a request would be submitted for an extension of the first ten-year interval to January 1998 to finish the risk-informed IST work.
The licensee's request for this extension was provided in their letter dated July 11, '1996.
Based on the start date of January 28,
- 1986, the licensee could change the date of the end of the first ten-year interval for Unit 1 to January 28, 1997 (ten years from start date plus one year allowed by the ASME Code).
Similarly, the licensee could change the end date for the first ten-year intervals for Units 2 and 3 to September 22,
- 1997, and January 8,
- 1999, respectively.
Therefore, the licensee is requesting extensions of 12 months for Unit 1
and 4 months for Unit 2 beyond the Code-allowed end dates for the first ten-year intervals.
The current and proposed interval schedules are identified below.
Unit Current First Interval Current Second Interval Proposed First Interval Proposed Second Interval 1
1/28/86 to 1/15/97 2
9/22/86 to 1/15/97 3
1/8/88 to 1 15/97 1/15/97 to 1/15/07 1/15/97 to 1
15 07 1/15/97 to 1
15 07 1/28/86 to 1
15 98 9/22/86 to 1
15 98 1/8/88 to 1
15 98 1/15/98 to 1/15 08 1/15/98 to 1 15/08 1/15/98 to 1/15 08 The licensee's requested extension of the IST intervals would delay updating their IST program to the ASME Code edition referenced in the regulations.
The licensee has been working with the staff as a pilot plant on the approval and implementation of a risk-informed IST program.
Completion of the update should have been factored 'into their participation as a pilot plant.
The staff does not consider participation in the risk-informed IST pilot program to be sufficient by itself to justify an extension.
Nevertheless, extending the interval by 12 months for Unit 1 and 4 months for Unit 2 will allow the licensee to place all three units at PVNGS on concurrent intervals.
The staff does not consider the small delay in updating the Palo Verde IST programs,to enhanced Code requirements to constitute a significant adverse safety condition.
The benefits that can be achieved through establishing concurrent intervals (e.g., training, common implementing procedures and
- programs, scheduling, and similarity of requirements) merit the extensions.
The proposed alternative testing intervals will provide an acceptable level of quality and safety because the licensee will continue to use the IST requirements from the first IST interval during the extension period for two units, which will provide the same level of quality and safety achieved for the other unit during the same time frame.
Because the three Palo Verde units will be on concurrent intervals, and the one year extension allowed by the ASNE code for Units 1 and 2 will have already been
- used, the licensee may not extend the second interval beyond the currently scheduled end of the Unit 3 second ten-year interval of January 15, 2008.
3.0 CONCLUSION
The extension of the first ten-year intervals for PVNGS Units 1 and 2 is hereby authorized pursuant to 10 CFR 50.55a(a)(3)(i),
with the provision that the licensee may not further adjust the second IST ten-year interval for any of the three units beyond January 15, 2008.
Principal Contributor:
J. Colaccino t
Date:
February 4,
1997