ML18066A359
| ML18066A359 | |
| Person / Time | |
|---|---|
| Site: | Palisades  |
| Issue date: | 12/28/1998 |
| From: | NRC (Affiliation Not Assigned) |
| To: | |
| Shared Package | |
| ML18066A358 | List: |
| References | |
| NUDOCS 9901050445 | |
| Download: ML18066A359 (3) | |
Text
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, I UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. 20555-0001 SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION RELATED TO REQUEST FOR RELIEF TO USE ASME OMa-1996 REQUIREMENTS AS AN ALTERNATIVE TO ASME OMa-1988 PART 4
1.0 INTRODUCTION
CONSUMERS ENERGY COMPANY PALISADES PLANT DOCKET NO. 50-255 The Code of Federal Regulations, 1 O CFR 50.55a, requires that inservice inspection {ISi) of certain American Society of Mechanical Engineers (ASME) Code Class 1, 2, and 3 components be performed in accordance with Section XI of the ASME Boiler and Pressure Vessel {B&PV)
Code applicable Edition and Addenda, except where specific written relief has been requested by the licensee and granted by the Commission pursuant to 1 O CFR 50.55a{g){6){i), or alternatives authorized pursuant to 1 O CFR 50.55a(a){3). In proposing alternatives, the licensee must demonstrate that: {i) the proposed alternatives provide an acceptable level of quality and safety; or (ii) compliance would result in hardship or unusual difficulty without a compensating increase in the level of quality and safety.
1 b CFR 50.55a authorizes the Commission to authorize an alternative from ASME Code requirements upon making the necessary findings. The NRC staff's finding with respect to authorizing the requested alternative as part of the licensee's ISi program is contained in this safety evaluation {SE).
This SE covers Revised Snubber Relief Request Number 1, submitted by Consumers Energy Company (the licensee) by letter dated March 13,1998, for authorization to use the examination requirements of the ASME OM Code, Subsection ISTD, 1995 Edition with the 1996 Addenda, in
- lieu of the ASME 1989 Edition of the ASME Code,Section XI, Subsection IWF-5300.
Subsection IWF 5300 contains inservice examination requirements that are to be performed in accordance with the first Addenda to ASME/ANSI OM;.1987, Part 4 (published in 1988), using the VT-3 visual examination method described in IWA-2213. The licensee's ISi program for the current interval is based on the requirements of the ASME B&PV Code,Section XI, 1989 Edition for the third 10-year ISi program at the Palisades Plant.
2.0 REQUEST FOR ALTERNATIVE EXAMINATION The licensee requests the use of an alternative from the ASME B&PV Code,Section XI, Article IWF 5000, Subarticle 5300 {a) requirement that inservice examinations be performed in accordance with the first Addenda to ASME/ANSI OM-1987, Part 4 (published in 1988), using the VT-3 visual examination method described in paragraph IWA-2213.
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2.1 Licensee's Proposed Alternative ASME OMa-1996, Subsection ISTD examination requirements will be used in lieu of the requirements contained in ASME 0Ma-1988(ASME/ANSI OM-1987), Part 4.
2.2 Licensee's Basis for Requested Alternative ASME OMa-1996, Subsection ISTD contains the scheduling interval provisions originally outlined in Generic Letter (GL) 90-09, "Alternative Requirements for Snubber Visual Inspection Intervals and Corrective Actions." The NRC staff developed GL 90-09 to provide an alternate schedule for visual inspections. These interval guidelines were approved for use at the Palisades Plant by letter dated June 13, 1992, and Technical Specification Amendment Number 164, dated April 20, 1995. Adoption of ASME OMa-1996, Subsection ISTD for snubber examination will therefore provide the same acceptable level of safety and quality as the requirements contained in the current plant examinations and GL 90-09. Further, the alternative provides for a 100-percent visual examination of the snubber population and a decrease in examination frequency if no unacceptable snubbers are found. If one or more unacceptable snubbers are found during a visual examination, the next examination interval will be 2/3 of the previous interval. Occupational radiation exposure will be reduced by performing examinations during outages and potentially at a reduced frequency.
3.0 EVALUATION The staff developed GL 90-09, in part, to reduce unnecessary radiological exposure during snubber inspections. GL 90-09 provides an alternate schedule for snubber visual inspections that maintains the same confidence level as the existing inspection intervals and allows for inspections and corrective actions during plant outages. The visual inspection provides for detection of impaired functional ability caused by physical damage, leakage, corrosion, or degradation from environmental exposure or operating conditions. The staff determined tt:iat the visual inspection schedule of GL 90-09 is an acceptable alternative and encouraged licensees to change snubber inspection programs to be consistent with this guidance.
ASME OMa-1996, Subsection ISTD, Preservice and lnservice Examination and Testing of Dynamic Restraints (Snubbers) In Light Water Reactors, is contained in the ASME Code for Operation and Maintenance of Nuclear Power Plants, 1995 Edition, with the 1996 Addenda. By regulation (1 O CFR 50.55a), through reference, the NRC endorses ASME Code requirements regarding inservice examination. The NRC has completed its review of the OM Code 1995 Edition, 1996 Addenda and proposed an amendment to 10 CFR 50.55a for endorsement to permit voluntary implementation of the OM Code, Subsection ISTD, 1995 Edition with the 1996 Addenda when the final rule is published. Further, Subsection ISTD visual inspection requirements are consistent with the guidance provided in GL 90-09.
By letter dated January 17, 1996, Consumers Energy submitted a request to use the guidance in GL 90-09 in snubber examination, that was subsequently approved by NRC in a letter dated June 2~, 1996. *The Consumers Energy letter of March 13, 1998, indicated that the revised request was needed to coordinate with a proposed change to the Technical Specification, and since Subsection ISTD contains the same requirements as allowed in GL 90-09 there will be ho change to the Palisades Plant snubber inspection program.
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Based on its review of the licensee's request, the staff has determined that the alternative proposed use of ASME OMa-1996, Subsection ISTD for inservice examination of snubbers at the Palisades Plant provides an acceptable level of quality and safety. The staff's approval is based on the following considerations:.(1) the request is consistent with the proposed amendment to 1 o CFR 50.55a (62 FR 63892) for endorsement of licensees' voluntary use of ASME OMa-1996, Subsection ISTD, (2) Subsection ISTD visual inspection requirements are consistent with GL 90-09 guidance, (3) the NRC June 28, 1996, letter, authorizing the use of GL 90-09 guidance for snubber visual inspections, and (4) Consumers Energy's letter indicating that the Palisades Plant snubber inspection program will not change sin_ce Subsection ISTD contains the same requirements as those contained in GL 90-09~ However, since the NRC's endorsement of ASME OMa-1996, Subsection ISTD cannot be authorized for generic implementation until the final rule is published, the staff's approval of the requested alternati~e is authorized only on an interim basis. The interim staff authorization will cease when the final rule is published.
4.0 CONCLUSION
The staff concludes that the revised request for snubber examination is authorized on an interim basis pursuant to 1 O CFR 50.55a(a)(3)(i) based on the determination that the licensee's proposed alternatives, together with the conditions described herein, provide an acceptable level of quality and safety.
Principal Contributor: F. Grubelich Date:
December 28, 1998