ML20203C281
| ML20203C281 | |
| Person / Time | |
|---|---|
| Site: | Vogtle  |
| Issue date: | 12/09/1997 |
| From: | NRC (Affiliation Not Assigned) |
| To: | |
| Shared Package | |
| ML20203C202 | List: |
| References | |
| NUDOCS 9712150271 | |
| Download: ML20203C281 (3) | |
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,j NUCLEAR REGULATORY COMMISSION
'2 WASHINGTON, D.C. 300tH001 i,.....,o SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION OF THE SECOND 10-YEAR INTERVAL INSERVICE INSPECTION PROGRAM PLAN REQUEST FOR REllEF RR 28 VOGTLE ELECTRIC GENERATING PLANT. UNITS 1 AND 2 SOUTHERN. NUCLEAR OPERATING COMPANY. INC.
DOCKET NOS. 50-424 AND 50-425
1.0 INTRODUCTION
t Title 10 of the Code of Federal Regulations (10 CFR), Section 50.55a, requires that inservice inspection (ISI) of certain American Society of Mechanical Engineers (ASME) Boller and Pressure Vessel Code (ASME Code) Class 1,2, and 3 components be performed in accordance with Section XI of the applicable Edition and Addenda, except where specific written relief he: ben requested by the licensee and granted by the Commission pursuant to paragraph 10 CFR 50.55a(g)(6)(l), or attematives approved pursuant to 10 CFR 50.55a(s)(3).
In proposed alternatives, the licensee must demonstrate that (i) the propored alternatives provide an acceptable level of quality and safety; or (ii) compliance would result !n hardship or unusual difficulty without a compensating increase in the level of quality and safety. In requ.yting relief, pursuant to 10 CFR 5').55a(g)(5), the licensee must demonstrate that the requirement is impractical for their facility.
This Safety Evaluation addresses a request dated May 29,1997, from Southern Nuclear Operating Company, Inc. (SNC or licensee) for approval to use ASME Code Case N 508-1, Rotation of Serviced Snubbers and Pressure Relief Valves for the Purpose of Testing, for Vogtle Electric Generating Plant (VEGP), Units 1 and 2, as an alternative to the ASME Code,Section XI requirements. The licensee's ISI program is based on the repair and replacement requirements of Section XI of the ASME Code,1989 Edition for the second 10 year ISI program.
The provisions of 10 CFR 50.55a authorize the Commission to grant relief from, and authorize alternatives to, ASME Code requirements upon making the necessary findings.
2.0 RP EF REQUEST The licena requests relief from the ASME Code,Section XI, Article IWA-7000 repair and replacement requirements for snubbers and pressure relief valves. The licensee proposes as an alternative to the ASME Code,Section XI requirements, to use ASME Code Case N-5081, for VEGP, Units 1 and 2.
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2 2.1 Licensee's Basis and_ Justification for Recuested Relief in its relief request, the licensee stated that the ASME Code Cace N 508-1 provides an alternative to IWA 7000 requirements. The licensee has reviewed the Code Case and determined its implementation will substantially reduce nonbeneficial work activities required by lWA 7000.
The licensee indicated that the ASME Code Comrnittee evaluated the proposed alternatives in Code Case N 5081 and determined they are acceptable for replacement activities involving snubber and relief valves that are rotated from stock and installed on components for the purpose of testing. The implementation of Code Case N 5081 will not effect the level of quality and safety, nor decrease the margin of public health and safety. The licensee further indicated that, while the cost savings associated with Code Case N 5081 have not been categorized as a Cost Beneficial Licensing Action, its implementation is consistent with the intent to eliminate nonbeneficial work activities and their associated costs. The licensee therefore requested that the proposed alternative be authorized pursuant to 10 CFR 50.55a(a)(3)(i).
2.2 Evaluation The ASME Code,Section XI, Article IWA 7000, Replacement, specihes the rules to be used when replacing items such as relief valves and snubbers. The article, in part, defines responsibilities that require the owner to develop a replacement program in accordance with IWA 7130, Replacement Program. The replacement program requires preparation of a replacement plan, completion of code Form NIS 2, Owner's Report for Repair or Replacement, performance of certain reviews and evaluations, reviews and concurrence by the Authorized Nuclear Inservice Insper: tor, documentation, and recordkeeping. These requirements apply l
even when removing and installing items solely for testing purposes.
Code Case N 508-1, provides an alternative to the provisions of Article IWA 7000 for snubbers and relief valves removed from components or piping systems for testing and replaced from stock. The Code Case specifies the following requirements:(1) items removed and replaced l
must be of the same design and construction; (2) items can only be removed and installed by mechanical meons; (3) items removed shall have no evidence of failure at the time of removal; (4) items being installed shall previously have been in service; (5) preservice inspection and pressure tests shall be performed as required by the applicable Edition and Addenda of Article IWA 7000. (6) the owner must maintain a method of tracking the item to ensure traceability of inservice inspection and testing records; (7) the use of Form NIS 2 is not needed except for repair or replacement of removed items; and (8) testing of removed snubbers and pressure relief valves, including sample expansions, shal: be performed in accordance with the owner's test program.
The relief request attemative states that the licensee will comply with the requirements of Code l
Case N 5081. This Code Case was approved by the ASME on May 11,1961. However, it has l
not been generich!!y approved for use by the NRC. The staff reviewed the Code Case and l
determined the current text of the Code Case may not, in some cases, provide adequate l
assurance that its application will not adversely impact the existing snubber service life monitoring program, i
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3 On the basis of the information provided in the licensee's Technical Requirements Manual, however, the staff has determined that the use of Code Case N 5081 at VEGP, Units 1 and 2, will not adversely impact the existing snubber service life monitoring program. Technical Requirement Surveillance (TRS) 13.7.2.4 addresses the staffs concems with regard to the Code Case impact on the existing snubber service life monitoring program. TRS 13.7.2.4 specifies that: (1) the maximum expected scrvice life for various seals, springs, and other critical parts shall be determined and established based on engineering information and shall be extended or shortened based on monitored test results and failure history; (2) critical parts shall be replaced so that the maximum life will not be exceeded during a period when the snubber is required to be operable; and (3) the parts replacement shall be documented and the documentation shall be retained for the operating license in accordance with the quality as surance requirements for such record retention. The TRS also requires verification, at 18 mc nth intervals, that the service life of the hydraulic and mechanical snubbers is not exceeded between surveillance inspectLns.
The licensee's proposed alternative to use Code Case N 5081 for the purpose of testing snubbers and pressure relief valves will eliminate unnecessary nonbeneficial work activities, reduce documentation and record requirements, minimize the time during which the affected system is out of service, and potentially reduce occupational radiation exposure. The licensee's proposed attemative to use Code Case N 5081 at VEGP, Units 1 and 2, provides an acceptable level of quality and safety in it provides adequate assurance of snubber performance in conjunction with the TRS requirements cited above.
3.0 CONCLUSION
S The staff conclu6es that the licensee's proposed attemative to use Code Case N 508-1 for rotation of serviced snubbers and pressure relief valves for the purpose of testing in lieu of ASME Code,Section XI, Article IWA 7000 requirements, for VEGP's, Units 1 arid 2, Second 10 Year Interval inservice Inspection Program, provides an acceptable level of quality and safety and is authorized pursuant to 10 CFR 50.55a(a)(3)(i).
Principal Contributor: F. Grubelich Date: December 9, 1997 i
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