ML15238B148
| ML15238B148 | |
| Person / Time | |
|---|---|
| Site: | Oconee  |
| Issue date: | 06/16/1980 |
| From: | Novak T Office of Nuclear Reactor Regulation |
| To: | Parker W DUKE POWER CO. |
| References | |
| NUDOCS 8007020314 | |
| Download: ML15238B148 (4) | |
Text
Distributibn:
Docket file JHeltemes, AEOD NRC PDR Gray file "J1UNE.
16980 LPD L PDR TERA NSIC Docket No. 50-269 NRR Rdg.
ORB#4-Rdg, DEisenhut Mr. William 0. Parker, Jr.
TNovak Vice President - Steam Production GLainas.
Duke Power Company RTedesco P. 0. Box 2178 RReid 422 South Church Street MFairtile Charlotte, North Carolina 28242.
RIngram Attorney, OELD
Dear Mr. Parker:
OI&E (3)
ACRS (16)
By letter dated June.8, 1978, Duke Power Company (DPC) requested an increase in the Oconee, Unit No. 1, Technical Specification steam generator tube leak rate limit from 0.3 gpm to 1.0 gpm.
We have concluded that DPC has not provided sufficient information to justify the increase. Our conclusion is based on the enclosed evaluation.
Unless we hear from you within 30,days,.we will termi
-::n nl*-;action o this item.
Sincerely, T. Novak, Assistant Director for Operating Reactors Division of Licensing
Enclosure:
As stated cc w/enclosure:
See next page 8007020,S~
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NRC FORM 318 (9-76) NRCM 0240 U.S-GOVERNMENT PRINTING OFFICE: 1979-289-369
UNITED STATES' NUCLEAR REGULATORY COMMISSION WASHINGTON, 0. C. 20555 June 16, 1980 Docket No. 50-269 Mr. William 0. Parker, Jr.
Vice President - Steam Production Duke Power Company P. 0. Box 2178 422 South Church Street Charlotte, North Carolina 28242
Dear Mr. Parker:
By letter dated June 8, 1978, Duke Power Company (DPC) requested an increase in the Oconee, Unit No. 1, Technical Specification steam generator tube leak rate limit from 0.3gpm to 1.0 gpm.
We have concluded that DPC has not provided sufficient information to justify the increase. Our conclusion is based on the enclosed evaluation. Unless we hear from you within 30 days, we will termi nate our action on this item.
Sincerely, T. Novak, Assistant Director for Operating Reactors Division of Licensing
Enclosure:
As stated cc w/enclosure:
See next page
EVALUATION OF OCONEE UNIT 1 PROPOSED TECHNICAL SPECIFICATION STEAM GENERATOR TUBE LEAKAGE RATE LIMIT Steam generator tube primary-to-secondary leakage gives an indication that the reactor coolant pressure boundary has been breached.I The technical specification steam generator tube leakage rtea imi is the last line of defense against unacceptable tube degra ation.
In the event that abnormally degraded tubes develop throuoh wall cracks during normal operation, the primary to secondary leak rate limi will ensure that any leaking tube has an adequate margin of safety to withstand the loads imposed during normal operation and postulated accidents.
To establsha leak rate limit that retain hs an adeuae agno sfty against tube fail1ure; it i s necessaryt kno the' burs pr ssue~nd leak rates associated with vaiu tps of through wall defects. The primary to secondary leak r l
under normal operating pressure should be less than th determined theoretically or experimentally for the most 1imiting single defect.
To date no theoretica or exerimental leak rate data has been submitted for Babcock and Wilcox (B&W) steam generators.
Furthermore, ytheonly tube burst data which has been submitted for B&W steam generator tubes (Attachment 2 to December 16, 1977 Letter Addressed to Mr. E. Case from rd e tPark
- r. dd a
sldesmesults for any through a rate wall defects. Therefore, apoer assessment ofteppsdleak rat e limit cannot be made.
The current 0.3 GPM leak rate limit was conservatively established based on leak rate and tube brstdata submittedby other vendors however, this data may not be fully'
- applicable to' B&W steam generator tubes.
Proper-assessment of. the leak 'rate limit forthe, Oconee B&W steam.
generators will require review of leak rate and, tube;'burst data for.
pos tated defects...In particular _this dalta: should be. madeavailable for' defect geometries.resemblin the erso"ad circunferential' ftigue 'cracks :which h, ave been, observed i n.the 'Oconee stem generator.
The' defects: Ishould be manufactu red't res'em bl e o.bserved tube de-gradto as accurately as possible. Circumferential cracks should preferably be introduced by a fatigue mechanism since mechanically machined or electric discharge mac hined lEDM)cracks are not as tight as tfatigue crcsadtend to overestimiate leak rates.' Burt,.and leak ~tests.should be conducted in'an. environment. approximating -real operating. conditions.
as nearly as ppacticable. In particular these tests should be conducted at the actual operating temperatur.
Wih0h tp of. data discussed. above it will,be.-possible to determi ne a,
leakage rate, limit' which w'ill, provide the. necessary,margins of. saf ety...
Until this type of information is made available itm is wextremely difficult to assure that the proposed 0 gp leak imt wi ensure steam geerator tube integri tyunder postulated accident conditions and the conservative 0.3 gpm leak.rate'limit shal I remainin. effect.
Duke Power Company cc w/enclosure(s):
Mr. William L. Porter Mr. Robert B. Borsum Duke Power Company Babcock & Wilcox..
P. 0. Box 2178 Nuclear Power Generation Division 422 South Church Street Suite 420,.7735 Old Georgetown Road Charlotte, North Carolina 28242 Bethesda, Maryland 20014 Oconee Public Library Manager, LIS 201 South Spring Street NUS Corporation Walhalla, South Carolina 29691 2536 Countryside Boulevard Clearwater, Florida 33515
.,Honorable James M. Phinney County Supervisor of Oconee County J. Michael McGarry, III, Esq.
Walhalla, South Carolina 29621 DeBevoise & Liberman 1200 17th Street, N.W.
Washington, D. C. 20036 Director, Technical Assessment Division Off ice of Radiation Programs (AW-459)
U. S. Environmental Protecti on Agency Office of Intergovernmental Relations Crystal Mall 2 116 West Jones Street Arlington, Virginia 20460 Raleigh North Carolina 27603 U. S. Environmental Protection Agency Region IV Office ATTN:
EIS COORDINATOR 345 Courtland Street, N.E.
Atlanta, Georgia 30308 Mr. Francis Jape U. S. Nuclear Regulatory Commissi on P 0. Box 7 Seneca, South Carolina 29678