ML20137Y069
| ML20137Y069 | |
| Person / Time | |
|---|---|
| Site: | Crystal River, 05000000 |
| Issue date: | 12/12/1985 |
| From: | Crutchfield D Office of Nuclear Reactor Regulation |
| To: | Oakes L BABCOCK & WILCOX OPERATING PLANTS OWNERS GROUP, WASHINGTON PUBLIC POWER SUPPLY SYSTEM |
| Shared Package | |
| ML20137Y048 | List: |
| References | |
| GL-84-04, GL-84-4, NUDOCS 8603120118 | |
| Download: ML20137Y069 (2) | |
Text
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umro states
'7 NUCLE AR REGULATORY COMMISSION h
WASHINGTON. D. C. 2065S
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December 12, 1985 Mr. L. C. Oakes, Chairman B&W Owners Group Leak-Before-Break Task Force Washington Public Power Authority P.O. Box 460 3000 George Washington Way Richland, Washington 99352 l
SUBJECT:
SAFETY EVALUATION OF B&W OWNERS GROUP REPORTS DEALING WITH ELIMINATION OF POSTULATED PIPE BREAKS IN PWR PRIMARY MAIN LOOPS
Reference:
- 1. B&W Owners Group report BAW-1847, Rev.1, " Leak-Before-Break Evaluation of Margins Against Full Break for RCS l
Primary Piping of B&W Designed NSS," September 1985.
- 2. B&W Owners Grou) Report BAW-1889P, " Piping Material Properties for Leak-Before-Break Analysis," A. L. Lowe, Jr., K. K. Yoon, and R. H. Emanuelson, October 1985,
- 3. proprietary.
NRC Generic Letter 84-04, " Safety Evaluation of i
Westinghouse Topical Reports Dealing with Elimination of Postulated Breaks in PWR Primary Main LOOPS,"
February 1,1984.
The NRC staff t.as completed its review of the referenced B&W Owners Group reports which apply "leat-before-break" technology as an alternative to designing against dynamic loads associated with postulated ruptures of primary coolant loop piping.
The staff evaluation concludes that an acceptable technical basis has been provided to eliminate as a design basis, the dynamic effects of large rupturesinthemainIoopprimarypipingoftheB&WOwnersGroupfacilities.*
Authorization by the NRC to not provide protection against the dynamic loads resulting from postulated breaks of primary main loop piping will require an exemption from General Design Criterion 4 (GDC4).
Such exemptions must
- 1.
ANO-1
- 5. Rancho Seco-
- 2. Midland-2
- 6. WNP-1
- 3. Oconee 1,2,3
- 7. Bellefonte 1 2
- 4. Crystal River 3
- 8. Davis-Bessei
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l f
t bejustifiedonafacilityspecificbasis.
Each request for an exemption should include a safety balance in accordance with the guidance provided in NRC Generic Letter 84-04 (Reference 3).
In addition, information for l
l each facility should be submitted to demonstrate.that leakage detection systems installed at the facility comply with Regulatory Guide 1.45.
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Reference 3 informed all operating PWR licensees, construction permit holders and applicants for construction permits of the staff's intent
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to proceed with rulemaking changes to GDC-4 to permit the use of analyses i
that demonstrate the probability of rupturing piping is extremely low under l
design basis conditions. On July 1, 1985, the Commission published a pro-l posed modification to GDC-4 which would permit the use of such analyses i
for PWR primary coolant loop piping. The NRC staff is currently in the process of final rulemaking.
Promulgation of the final rule will eliminate the need for exemption requests and performance of safety balances; how-i r
ever the requested information on leakage detection systems should be submitted.
By copy of this letter with enclosed safety evaluation report Mr.J.F.WaltersofBabcock&Wilcoxisbeinginformedofthlsaction.
i i
This information is also being transmitted to participating licensees and applicants of the B&W Owners Group.
Sincerely, l
[
r D9ennsM.m&hfed J
Crutc sistant Director i
l for Technical Support Division of PWR Licensing-S f
l l
Office of Nuclear Reactor Regulation l
l
Enclosure:
As stated cc:
J. F. Walters, B&W I
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