NUREG-0819, Ack Receipt of 850920 Request for Exemption from Postulating Pipe Breaks in Primary Coolant Loop Piping,Per Generic Ltr 84-04, Safety Evaluation of Pipe Breaks in PWR Primary Main Loops. Request Obviated by Issuance of GDC 4 on 860411

Ack Receipt of 850920 Request for Exemption from Postulating Pipe Breaks in Primary Coolant Loop Piping,Per Generic Ltr 84-04, Safety Evaluation of Pipe Breaks in PWR Primary Main Loops. Request Obviated by Issuance of GDC 4 on 860411

ML13331B205
Person / Time
Site:	San Onofre
Issue date:	07/25/1989
From:	Trammell C Office of Nuclear Reactor Regulation
To:	Baskin K Southern California Edison Co
References
GL-84-004, RTR-NUREG-0819, RTR-NUREG-819, RTR-REGGD-01.045, RTR-REGGD-1.045 NUDOCS 8907310348
Download: ML13331B205 (5)

Text

09 UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D. C. 20555 0s July 25, 1989 Docket No.:

50-206 Mr. Kenneth P. Baskin Vice President Southern California Edison Company 2244 Walnut Grove Avenue Post Office Box 800 Rosemead, California 91770

SUBJECT:

ELIMINATION OF POSTULATED PIPE BREAKS IN PRIMARY COOLANT LOOP PIPING (TAC NO. 59896)

Re: San Onofre Nuclear Generating Station, Unit No. 1 This refers to your letter of September 20, 1985 in which you requested an exemption from General Design Criterion 4 contained in Appendix A to 10 CFR Part 50. Specifically, you requested that Southern California Edison Company be exempted from postulating pipe breaks in the primary main loops for San Onofre Unit No. 1 for the purposes of defining structural loads on or within the reactor vessel and the reactor coolant system main loops. This means that pipe whip restraints and other protective measures against the dynamic effects of a break in the main coolant piping would not be required.

Your request was based on Generic Letter 84-04, "Safety Evaluation of Westing house Topical Reports Dealing with Elimination of Postulated Pipe Breaks in PWR Primary Main Loops" dated February 1, 1984. Generic Letter 84-04 approved the elimination of postulated pipe breaks as described above subject to two conditions relevant to San Onofre Unit No. 1: (1) that SCE request an exemption from GDC 4, and (2) that leakage detection systems inside containment be adequate to detect a leak of one gpm within four hours and meet most other guidance contained in Regulatory Guide 1.45, "Reactor Coolant Pressure Boundary Leakage Detection Systems."

Subsequent to the issuance of GL 84-04 and your exemption request, the NRC modified GDC 4 on April 11, 1986 (54 FR 12502) by adding the following phrase to GDC 4:

"However, the dynamic effects associated with postulated pipe ruptures of primary coolant loop piping in pressurized water reactors may be excluded from the design basis when analyses demonstrate the probability of rupturing such piping is extremely low under design basis conditions."

3907310348 890725 PDR ADOCK 05000206 P

PDC,

00 Mr. Kenneth July 25, 1989 The issuance of this rule makes the issuance of an exemption unnecessary provided that the conditions of GL 84-04 are otherwise satisfied. The matter of primary coolant system leak detection was reviewed in NUREG-0819, "Integrated Plant Safety Assessment", section 4.18, Topic V-5, "Reactor Coolant Pressure Boundary Leakage Detection" and relevant open items resulting from this review were resolved by the issuance of Amendment No. 119 on February 6, 1989. Since you satisfy the conditions of GL 84-04, your request for exemption is no longer necessary and NRC action on this matter is complete.

Sincerely, Charles M. Trammell, Senior Project Manager Project Directorate V Division of Reactor Projects - III, IV, V and Special Projects cc: See next page

Mr. Kenneth July 25, 1989 The issuance of this rule makes the issuance of an exemption unnecessary provided that the conditions of GL 84-04 are otherwise satisfied. The matter of primary coolant system leak detection was reviewed in NUREG-0819, "Integrated Plant Safety Assessment", section 4.18, Topic V-5, "Reactor Coolant Pressure Boundary Leakage Detection" and relevant open items resulting from this review were resolved by the issuance of Amendment No. 119 on February 6, 1989. Since you satisfy the conditions of GL 84-04, your request for exemption is no longer necessary and NRC action on this matter is complete.

Sincerely, original signed by Charles M. Trammell, Senior Project Manager Project Directorate V Division of Reactor Projects -

III, IV, V and Special Projects cc: See next page DISTRIBUTION Docket File NRC & LPDRs CTrammell (2)

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Mr. Kenneth P. Baskin San Onofre Nuclear Generating Southern California Edison Company Station, Unit No. 1 cc David R. Pigott Mr. F. B. Marsh, Project Manager Orrick, Herrington & Sutcliffe Bechtel Power Corporation 600 Montgomery Street P. 0. Box 60860 San Francisco, California 94111 Terminal Annex Los Angeles, California 90060 Mr. Robert G. Lacy Manager, Nuclear San Diego Gas'& Electric Company P. 0. Box 1831 San Diego, California 92112 Resident Inspector/San Onofre NPS U.S. NRC P. 0. Box 4329 San Clemente, California 92672 Mayor City of San Clemente San Clemente, California 92672 Chairman Board of Supervisors County of San Diego 1600 Pacific Highway Room 335 San Diego, California 92101 Regional Administrator, Region V U.S. Nuclear Regulatory Commission 1450 Maria Lane, Suite 210 Walnut Creek, California 94596 Dr. Gerard C. Wong, Chief Radiological Materials Control Section State Department of Health Services 714 P Street, Office Bldg. #8 Sacramento, California 95814 Mr. Don Womeldorf Chief Environmental Management California Department of Health 714 P Street, Room 616 Sacramento, California 95814 (9)