ML20206E597
| ML20206E597 | |
| Person / Time | |
|---|---|
| Issue date: | 06/09/1986 |
| From: | Arlotto G NRC OFFICE OF NUCLEAR REGULATORY RESEARCH (RES) |
| To: | Speis T Office of Nuclear Reactor Regulation |
| Shared Package | |
| ML20205C260 | List: |
| References | |
| FOIA-88-464 NUDOCS 8811180134 | |
| Download: ML20206E597 (2) | |
Text
UNITED STATES
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f kg NUCLE AR REGULATORY COMMISSION W ASHING T ON. D. C. 20555 h j k...../ JUN 9 5986 -
MEMORANDUM FOR: Themis P. Speis Director Division of Safety Review and Oversight NRR FROM: Guy A. Arlotto, Director Division of Engineering Technology RES
SUBJECT:
RECOMMENDED ACTIONS REGARDING DECOUPLING OF SEISMIC **
AND PIPE RUPTURE LOADS The USNRC Piping Review Comittee in Volume 5 of NUREG-1061 made a recomendation to decouple seismic and pipe rupture loads for the mechanical design of components and their supports when adequate technical evidence is presented. Subsequently. in a July 30, 1985 memorandum from R. B. Minogue to W. J.
Dircks, it was indicated that this would be accomplished through 6 revision to SRP 3.9.3. Accordingly, on March 12, 1986, I distributed for comment a proposed revision to SRP 3.9.3.
In a May 15, 1986 note from Scinto to me (enclosure 1), it was stated that if SRP 3.9.3 were revised without also revising SRP 3.8.1 through SRP 3.8.4, then an inconsistency would be introduced in the SRP which would require rulemaking. SRP 3.8.1 through SRP 3.8.4 deal with load combinations for structures (including containments), whereas SRP 3.9.3 1, 2 and 3 components, deals with load combinations for ASMEThus Classit appears that two courses supports and core support structures.
are legally available to us:
- 1. undertake rulemaking which would allow decoupling of seismic loads and pipe rupture loads for mechanical components only, or,
- 2. avoid rulemaking, but expand the scope of the SRP revision to structures as well as mechanical equipment.
A third option, not explicitly mentioned in the Scinto note is:
- 3. do nothing with regard to rulemaking and SRP revisions, and handle the relatively few licensing actions involving decoupling as deviations from SRP 3.9.3. I understand that only four CE plants have equested the use of decoupling to respond to multi-plant action item 0-10 (asytretric blowdown).
My view is that there is insufficient technical bases to expand decoupling perfo rced.
to structures (item 2 above) unless further work is Controversial and potentially time co.1suming issues that could arise from applying decoupling to structures wwld involve:
! 1. distinguishing betweer Icng-term and short-term pipe rupture effects when decoupling pipa tupture loads from seismic loads, and, l
- 2. the question as to whetter containments should be treated O ...rt 1 y thn other stry' - Fo 2 4- Pfr- Wy 1
8811180134 081104 gg PDR FOIA CHAPHAN88-464 PDR
JLW 9 1966 I recommend that deviations to SRP 3.9.3 continue to be used, and that rulemaking to revise GOC-2 be initiated in parallel. Finally, I feel that we should seek early advice from the CRGR on the prudence of this course so that resources will be optimized. In the mean time, all work on revising SRP 3.9.3 is suspended.
{ '
yA'Arlo!to', Director Divis on of Engineering Technology, RES
Enclosure:
As stated {
cc: H. Thorrpson, NRR R. Bernero, NRR F. Miraglia,NFi E. Jordan, IE S. Ebneter, RI A. Bibson, RII C. Paperiello, R!l!
R. Denise, RIV D. Kirsch, RV J. Scinto, OELO W. Shields, 0ELO R. Bosnak, NRR F. Cherny, NRR H. Wong, IE K. Kniel NRR J. Sniezek, CRGR