ML20011A713

Final Deficiency Rept Re Inlet Piping Configurations for Pressurizer Safety Relief Valves W/Large Pressure Drops Possibly Leading to Valve Chatter,Initially Reported 810916. Inlet Piping Design Will Be Revised to Limit Pressure Loss

ML20011A713
Person / Time
Site:	North Anna
Issue date:	10/19/1981
From:	Spencer W VIRGINIA POWER (VIRGINIA ELECTRIC & POWER CO.)
To:	James O'Reilly NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II)
References
10CFR-050.55E, 10CFR-50.55E, 568, NUDOCS 8110290326
Download: ML20011A713 (1)

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\% . . /f Mr. James P. O'Reilly, Director IS[e131No.568-Office of Inspection & Enforcement PSE&CS/RLR:bw U.S. Nuclear Regulatory Commission Region II 101 Marietta Street, . Suite 3100 Docket No. 50-404 Atlanta, Georgia 30303

Dear Mr. O'Reilly:

On September 16,'1981, as required by the provisions of 10CFR50.55(e), a design condition having potential safety significance was reported.

An EPRI_ testing program for pressu.izer safety relief valves has indicated -

that inlet piping configurations with large pressure crops can lead to valve chatter. _ Valve chatter could lead to valve damage and result in the possible overpressurization of the pressurizer relief tank. This would result in a leak of primary coolant into the reactor containment.

A review of the :s th Mru. Unit 3 inlet piping to the pressurizer safety relief valve has ind:r. ,ted thd it ..culd have sufficient pressure loss to cause valve chatter.

Our techitect Engineer, Stone & Webster, has been notified of this situation and instructed to revise the inlet piping design. The inlet piping design will be revised to limit the inlet pressure loss sufficiently.to ensure that valve chatter will not occur.

The final inlet piping design will permit satisf actory pressurizer safety relief valve operation.-

i- This is considered 'to be the-final report on this subject.

Very truly yours, 3 W. . C. Spence Vice President Power Station Engineering and Construction -Services cc: Mr. Robert L. Tedesco-JDivision of Licensing 8110290326 81101'9' PDR ADOCK 0500040*

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