ML13308B520
| ML13308B520 | |
| Person / Time | |
|---|---|
| Site: | San Onofre  |
| Issue date: | 12/23/1976 |
| From: | Johari Moore SOUTHERN CALIFORNIA EDISON CO. |
| To: | Engelken R NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION V) |
| References | |
| IEC-76-06, IEC-76-6, NUDOCS 8103110089 | |
| Download: ML13308B520 (2) | |
Text
Southern California Edison Company SCE P. 0. BOX 800 2244 WALNUT GROVE AVENUE JACK B. MOORE ROSEMEAD, CALIFORNIA 91770 TELEPHONE
.e. n.o.
213-572-2292 December 23, 1976 U. S.'Nuclear Regulatory Commission Region V Office of Inspection and Enforcement Suite 202, Walnut Creek Plaza 1990 North California Boulevard Walnut Creek, California 94596 Docket No. 50-206 Attention:
Mr. R. H. Engelken
Dear Sir:
IE Circular No. 76-06 Stress Corrosion Cracks in Stagnant, Low Pressure Stainless Piping Containing Boric Acid Solution at PWR's
Reference:
(1) Letter from NRC Division of Operating Reactors (Robert A. Purple) to SCE (Jack B. Moore) dated April 22, 1976)
Reference is made to your correspondence of November 24, 1976, forwarding the subject circular. Described in the circular are the circumstances which led to its issuance and a request for action to be taken by the licensee. Forwarded herewith is the information requested.
We have identified safety-related piping systems at San Onofre Unit 1 where dynamic flow conditions do not exist during normal operation. These include the safety injection, recirculation, containment spray and residual heat removal systems. It should be pointed out that refueling operations result in the flushing of these systems with minor exceptions. We intend to incorporate procedural changes which will eliminate these minor exceptions and assure that all areas of the identified systems are completely flushed at least at refueling intervals.
-2 Surveillance requirements exist that will result in examination of the identified systems during the current refueling outage. Technical Specification surveillance standards provide for the inspection, including hydrostatic testing, of the major part of the recirculation and containment spray systems. In Service Inspection requirements, including volumetric and hydrostatic tests, cover portions of the residual heat removal and safety injection systems. We will, additionally, provide for the visual inspection of all areas of the identified systems not covered by the surveillance requirements during the current refueling outage.
A summary report of the results of all examinations conducted during the current refueling outage on the identified systems will be forwarded to the Regional Office within 60 days from the date of completion. Any adverse findings will be reported within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />.
The surveillance requirements for the aforementioned systems will, however, be modified in the near future. In response to reference (1),
we are reconsti tuting our ISI program to comply with the provisions of ASME Section XI. As such, the specific examination requirements will subsequently be determined by applicable portions of ASME Section XI.
Our revised ISI program will, additionally, consider non-destructive volumetric examination of a representative number of circumferential pipe welds in areas of the identified systems which are not hydrostatically tested. The areas examined will be expanded to cover a distance of approximately six (6) times the pipe wall thickness (not less than 2 inches but not exceeding 8 inches) on each side of the weld. Supplementary examination techniques will be used, as necessary, for evaluation or confirmation of ultrasonic indications.
If you have any questions concerning our response, or should you require additional information, please contact me.
cc: Director, USNRC, -Office of Inspection & Enforcement