ML13333A484
| ML13333A484 | |
| Person / Time | |
|---|---|
| Site: | San Onofre  |
| Issue date: | 01/04/1980 |
| From: | Ziemann D, Ziemann Z Office of Nuclear Reactor Regulation |
| To: | James Drake SOUTHERN CALIFORNIA EDISON CO. |
| References | |
| TASK-03-05.A, TASK-03-05.B, TASK-3-5.A, TASK-3-5.B, TASK-RR NUDOCS 8002070337 | |
| Download: ML13333A484 (3) | |
Text
Docket No. 50-206 t
ll Mr. James H. Drake Vice President Southern California Edison Company 2244 Walnut Grove Avenue Post Office Box 800 Rosemead, California 91770
Dear Mr. Drake:
RE:
SYSTEMATIC EVALUATION PROGRAM TOPICS III-5.A (EFFECTS OF PIPE BREAK ON STRUCTURE, SYSTEMS AND COMPONENTS INSIDE CONTAINMENT) AND III-5.B (PIPE BREAK OUTSIDE CONTAINMENT)
On September 12, 1970, representatives of the Systematic Evaluation Program (SEP) licensees met with the staff and indicated their concern over uncertainty related to:
- 1. The intent of footnote 14 to Regulatory Guide 1.46 and Section B.2.b.(2) of Branch Technical Position APCSB 3-1 (attached to Standard Review Plan Section 3.6.1) with respect to when pipe whip loads are to be evaluated in impacted pipes of nominal sizes equal to or greater than that of the postulated broken pipe; and
- 2.
The criteria with respect to when jet impingement loads are to be evaluated in impinged pipes.
The above points are essential elements of the referenced SEP Topics. As a result, the SEP Branch, Division of Operating Reactors, has had frequent meetings with the Mechanical Engineering Branch (MEB), Division of Systems Safety, to ensure that the position given below is in agreement with current criteria used in evaluating plants under review for both Construction Permits and Operating Licenses.
It is the staff's position that when evaluating the pipe whip impact and jet impingement effects of postulated pipe breaks for SEP Topics III-5.A and III-5.B, the following criteria shall apply:
- 1. A whipping pipe should be considered capable of rupturing impacted pipes of smaller nominal size.
- 2. A whipping pipe should be considered capable of developing through wall leakage cracks in impacted pipes of equal or larger nominal sizes with thinner wall thicknesses.
-S 0 207 O F F IC E,.......................
............................./.................................................
S U R N A M E D A T E....................................
NRC FORM 318 (9-76) NRCM 0240
- U.S.
GOVERNMENT PRINTING OFFICE: 1979-289-369
Mr. James '
9
- 3. A whipping pipe may be considered incapable of rupturing or cracking impacted pipes of equal or larger nominal sizes with equal or larger wall thicknesses.
Confirmatory analysis is not required.
- 4. The effects of jet impingement loads should be considered and evaluated regardless of the ratio of impinged and postulated broken pipe sizes, even if evaluation for pipe whip impact is not required by criterion 3 above.
The staff will consider analytical and experimental justification for the use of less conservative criteria by the licensees on either a generic or case by-case basis.
Sincerely, Dennis L. Ziemann, Chief, Operating Reactors Branch #2 Division of Operating Reactors cc:
See next page DISTRIBUTION Docket NRC PDR Local PDR ORB #2 Reading NRR Reading DEisenhut RVollmer OELD OI&E (3)
DLZiemann PWO'Connor HSmith DCrutchfield (2)
OFF ICE DOR:ORB #
DOR DOR:0RB #2 PW.O'onnor:ah DCyc field DLZiemann NC TERM38(97)NRM04 U GOVERNMENT PR INTING OFFICE:.
1979-289 NRC FORM 318 (9-76) NRCM 0240 1'US. GOVERNMENT PRINTING OFFICE: 1979-289-369
Mr. James January 4, 198n cc Charles R. Kocher, Assistant Director, Technical Assessment General Counsel Division Southern California Edison Company Office of Radiation Programs Post Office Box 800 (AW-459)
Rosemead, California 91770 U. S. Environmental Protection Agency David R. Pigott Crystal Mall #2 Samuel B. Casey Arlington, Virginia 20460 Chickering & Gregory Three Embarcadero Center U. S. Environmental Protection Twenty-Third Floor Agency San Francisco, California 94111 Region IX Office ATTN:
EIS COORDINATOR Jack E. Thomas 215 Freemont Street Harry B. Stoehr San Francisco, California 94111 San Diego Gas & Electric Company P. 0. Box 1831 K M C, Inc.
San Diego, California 92112 ATTN:
Richard Schaffstall 1747 Pennsylvania Avenue, N. W.
U. S. Nuclear Regulatory Commission Suite 1050 ATTN:
Robert J. Pate Washington, D. C. 20006 P. 0. Box 4167 San Clemente, California 92672 Mission Viejo Branch Library 24851 Chrisanta Drive Mission Viejo, California 92676 Mayor City of San Clemente San Clemente, California 92672 Chairman Board of Supervisors County of San Diego San Diego, California 92101 California Department of Health ATTN:
Chief, Environmental Radiation Control Unit Radiological Health Section 714 P Street, Room 498 Sacramento, California 95814