ML20100J114
| ML20100J114 | |
| Person / Time | |
|---|---|
| Site: | Sequoyah  |
| Issue date: | 02/23/1996 |
| From: | Shell R TENNESSEE VALLEY AUTHORITY |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| NUDOCS 9602280263 | |
| Download: ML20100J114 (4) | |
Text
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l Tennessee Valley Authonty. Post Offte Box 2000. Soody Daesy Tennessee 37379 February 23,1996 U.S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, D.C. 20555 Gentlemen:
In the Matter of
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Docket Nos. 50-327 Tennessee Valley Authority
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50-328 SEQUOYAH NUCLEAR PLANT (SON)- ADDITIONAL INFORMATION FOR AMERICAN SOCIETY OF MECHANICAL ENGINEERS (ASME) SECTION XI RELIEF REQUEST -
Reference:
TVA letter to NRC dated October 26,1995, "Sequoyah Nuclear Plant (SON) - American Society of Mechanical Engineers (ASME)Section XI Relief Request - Snubbers" During a telephone conference call with the NRC staff on February 16,1996, NRC requested that TVA provide clarification regarding the use of the word " exempt" and the word " applicable" that are contained in TVA's referenced relief request letter.
TVA has enclosed a revised relief request to alter the language and remove the word exempt. This change in language will serve to clarify that no snubbers are exempt from SON technical specification (TS) requirements, but that TS requirements act as alternative requirements to the ASME code.
Applicable snubbers, as stated in TVA's referenced relief request letter, refers to the population of snubbers that are ASME Code Class 1,2, and 3 r/ mponents. This population is a subset of the total population of snubbers that are controlled by the requirements of SON TSs. Accordingly, relief is requested to enable the ASME population of snubbers (i.e., applicable snubbers) to be tested in accordance with the TS requirements rather than ASME code requirements.
Enclosed is Revision 1 of TVA's snubber relief request. Revision 1 supersedes the relief request previously provided by the referenced letter. Following NRC approval of the proposed relief request, TVA plans to incorporate the relief request into SON's i
Snubber Test Program.
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9602280263 960223 PDR ADOCK 05000327 P
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U.S. Nuclear Regulatory Commission Page 2 February 23,1996 Please direct questions concerning this issue to D. V. Goodin at (423) 843-7734.
1 Sincerely, l
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R. H. Shell Manager i
SON Site Licensing i
Enclosure -
cc (Enclosure):
Mr. D. E. LaBarge, Project Manager l
Nuclear Regulatory Commission One White Flint, North 11555 Rockville Pike Rockville, Maryland 20852-2739 NRC Resident inspector
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Sequoyah Nuclear Plant 2600 Igou Ferry Road i
Soddy-Daisy, Tennessee 37379-3624 i
Regional Administrator i
U.S. Nuclear Regulatory Commission Region 11 101 Marietta Street, NW, Suite 2900
'l Atlanta, Georgia 30323-2711 t
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SNUBBER REllEF REQUEST
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Revision 1 l
Comoonents:
1 American Society of Mechanical Engineers (ASME)Section XI Code Class 1,2, and 3 snubbers.
Code Reauirements-i ASME Boiler and Pressure Vessel Code,Section XI,1989 Edition, Subarticles, IWF-5200 and-IWF 5300 require that examinations and testing be performed in accordance with the 1988 Addenda to ASME/ ANSI OM-1987, Part 4. These requirements provide the methodology and corrective actions for examining and functionally testing snubbers. In addition, lWA-6230-requires in-service inspection (ISI) summary reports for snubbers to be filed with the regulatory authority, and IWA-2100 requires authorized nuclear in-service inspector involvement for snubber cxamination and testing.
1 Relief Reauest-l Relief is requested from the requirements of IWF-5200, IWF-5300, and IWA-6230 as described above. As an alternative, TVA proposes to perform examination and testing of snubbers in accordance with technical specifications (TSs).
Alternate Examination and Test:
SON will pedorm examination and testing of snubbers as required by TS 3/4.7.9, " Snubbers."
Basis for Relief:
Sequoyah Nuclear Plant (SON) is required to incorporate the 1989 Edition of ASME Section XI Code as the governing document for the second ten-year ISIinterval. These requirements i
contain snubber examination and testing methodologies that are nearly identical to the methodologies preceribed in the TS for examination and testing of snubbers. Having two nearly redundant sets of snubber requirements presents unnecessary confusion in sample selection, data collection, acceptance criteria, and corrective actions. These requirements willin some cases cause a duplication of test documentation, in other cases, additional confusion is created by the differenco in snubber categories. Approximately half of the snubbers at SON are required to be tested by both TSs and ASME Section XI. The other half are cnly required to be tested by TS requirements. Therefore, sampling becomes very confusing since some snubbers may be applicable to both requirements and others to only one. For the same reason, acceptance criteria and corrective action become difficult to apply.
One area where the requirements do not closely resemble each other is the snubber examination schedules. Snubber examination currently performed under TS 3/4.7.9, has been amended in accordance with Generic Letter (GL) 90-09, " Alternative Requirements for Snubber Visual inspection Intervals and Corrective Actions." The purpose of the GL was to provide alternative guidance to snubber inspection schedules that were excessively restrictive. The alternative schedule was to alleviate the expenditure of unnecessary resources and prevent radiological I
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2 exposure associated with the over restrictive examination schedule. The implementation of ASME/ ANSI OM-1987, Part 4, would return the examination schedule for approximately half of the snubbers in the examination program to the frequency which existed prior to the publication of GL 90-09, effectively cancelling the relaxation provided by GL 90-09.
Justification:
The current program, as defined by TS 3/4.7.9, provides for a level of quality and safety equal to or greater than that of the OM Code. The OM Code provides for failure mode grouping of snubbers that fail visual examination, meaning only those snubbers identified as being in that group would require shortened examination intervals. Under the existing TS program, all snubbers in the population would be placed in a shortened inspection interval. On this basis, the existing TS program is more conservative in corrective action than the OM Code requirements.
The alternative examination criteria is based on GL 90-09. As described above, the differences can create confusion while selecting test samples, applying acceptance criteria, corrective action, and examination schedules for failed snubbers. This situation could increase the possibility of applying the wrong action, thus creating a nonconformance, an inoperability or even a violation of TSs.
in order to eliminate any misinterpretation or confusion in administering similar requirements for snubbers that partially overlap, and to remove the possibility of applying contradicting requirements to the same snubber (s), TVA proposes to examine and test snubbers in accordance with SON TS 3/4.7.9. TS requirements for testing and examination of snubbers provide an equal or greater level of quality and safety than ASME Section XI Code.
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Conclusion:==
Based on the above justification,it is concluded that in-service examination and testing of l
snubbers, in accordance with the 1988 Addenda to ASME/ ANSI OM-1987, Part 4, would result in hardship or unusual difficulty without a compensating increase in the level of quality and safety. SON's examination and testing of snubbers, in accordance with TS 3/4.7.9, will provide an acceptable level of quality and safety. Therefore, pursuant to 10 CFR 50.55a(a)(3),it is requested that relief be granted.
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