ML20010D015

Interim Deficiency Rept Re RCS Attached Piping,Initially Reported 810129.All Piping/Instrumentation Connections to RCS Will Be Analyzed to Ensure Adequate Design.Final Rept Will Be Provided.Also Reported Per Part 21

ML20010D015
Person / Time
Site:	North Anna
Issue date:	02/27/1981
From:	Spencer W VIRGINIA POWER (VIRGINIA ELECTRIC & POWER CO.)
To:	James O'Reilly NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II)
References
REF-PT21-81-002-032 10CFR-050.55E, 10CFR-50.55E, 10CFRR-50.55E, 137, NUDOCS 8108210379
Download: ML20010D015 (1)

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is F/ec-03h February 27, 1981 M?. James P. O'Reilly, Director Serial No. 137 Office of Inspection and Enforcement PSE&C/DCC:jmc U.S. Nuclear Regulatory Commission W Region II DocketNoh3404//

101 Marietta Street, Suite 3100 Atlanta, Georgia 30303 g 9 Q 4 ,, 4-\

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.s b oj Dear Mr. O'Reilly- [

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90 l3 REACTOR COOLANT SYSTEM ATTACHED PIPING

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NORTH ANNA llNIT 3 ,,, 3 x, On January 29, 1981, NRC Region II was notified under the provisions'of 10CFR50.55 (e) concerning an apparent disconnect between the assumptions relative to pipe breaks in the Loss of Coolant Accident (LOCA) analysis and the structural analysis for certain connecting piping in the affected Reactor Coolant System (RCS) loop. This item was also reported as being covered by 10CFR21. In accordance with the applicable reporting requir(ments, we submit this 30 day report as an Interim Report on this matter.

The report stated that the current Babcock and Wilcox Emergency Core Cooling System (ECCS) analyses for LOCA do not consider the consequential f ailure of piping and instrumentation connections to the RCS. Certain of these lines and connections may not have been evaluated to verify their structural ~ integrity under the postulated accident conditions. In the event of a LOCA, the failure of these attached piping and instrumentation connections could represent an inctinsistency with the ECCS analysis.

As a result of careful evaluation, a plan has beer implemented for addressing these concerns. All piping and instrumentation connections to the Reactor Coolant System required to maintain function or resist consequential f ailure as a result of a LOCA will ~ae analyzed to ensure that they are adequately designed. Any items that cannot be shown to be acceptable will be redesigned as necessary.

As noted above, this letter represents an interim report. A final report will be filed following the resolution of this matter.

Very tr ly yours, W. . Spencer Vice President - Power Station Engineering and Construction Services cc: Mr. Robert L. Tedesco Division of Licensing 8108210379 810227 O PDR ADOCK 05000404 S /y 5 /

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