ML20036A687
| ML20036A687 | |
| Person / Time | |
|---|---|
| Site: | Catawba  |
| Issue date: | 04/29/1993 |
| From: | Tuckman M DUKE POWER CO. |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| Shared Package | |
| ML19311B008 | List: |
| References | |
| NUDOCS 9305130118 | |
| Download: ML20036A687 (4) | |
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)urL SC29^45 (803)83134261XX DUKEPOWER April 29,1993 U. S. Nuclear Regulatory Commission Attention: Document Control Desk Washington, D. C.
20555
Subject:
Catawba Nuclear Station, Unit I Docket No. 50-413 Additional Information Supponing Catawba Unit i Opemtion for the Remainder of Cycle 7 On April 1,1993, Catawba Nuclear Station met with the NRC staff to discuss technical information which Catawba submitted to suppon the Interim Plugging Criteria (IPC) which was granted by the NRC on September 25,1992 for Catawba Unit 1 Cycle 7. In this meeting and subsequent discussions, the NRC staff requested and Catawba committed to provide postulated steam line break (SG) leakage rate calculations for Catawba Unit 1 based on the assumption of an average leak rate for the measured data independent of j
bobbin pmbe voltage and the inclusion of a probability of detection. SG leakage rate calculations were submitted'on April 8, 21, and 22,1993 in response to these requests.
The enclosed WCAP represents a compilation of all the SG leakage calculations that have 7
been completed to date.
1 The intent of these calculations is to provide a " reasonable estimate" of the total primary to secondary leakage rate that can be expected during a postulated steam line break event.
The results indicate an upper 95% confidence bound leakage rate of 2.73 gallons per minute (gpm) in Steam Generator C when considering all of the test data. If only the data obtained from tubes with a bobbin voltage ofless than approximately 9 volts are included, j
an upper 95 % confidence bound leakage rate of 0.60 gpm is obtained. The calculated SG leakage rate in Steam Generator C has been shown to bound the postulated leakage ate fmm the remaining Catawba Unit I steam generators.
l This WCAP also shows by statistical assessments that the significance level of the cormlation between SG leakage and bobbin voltage is greater than 99.9%. Therefore, the use of an average value independent of bobbin probe voltage in determining the SG leakage mte is unnecessarily conservative, and the leakage rate value calculated in WCAP-13494, Rev. I should be utilized in assessing the radiological consequences of a postulated SG. Both deterministic and Monte Carlo analyses show that SG leakage rates at the end of cycle. (EOC) 7 are negligible, i.e.. less than 0.1 gpm in contmst to the 1.0 gpm SLB accident analpigsprgon inchided in the Catawba SAR.
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U. S. Nuclear Regulatory Commission l
April 29,1993 Page 2 Enclosed are:
1.
5 copies of WCAP-13715, "NRC Requested Catawba 1 S/G Leakage Evaluation" (Pmprietary).
I 2.
5 copies of WCAP-13716, "NRC Requested Catawba 1 S/G Leakage Evaluation" l
(Non-Proprietary).
Also enclosed are a Westinghouse authorization letter, CAW-93-458, an accompanying affidavit, a Proprietary Infonnation Notice, and a Copyright Notice.
As item I contains information proprietary to Westinghouse Electric Corporation, it is supported by an affidavit signed by Westinghouse, the owner of the infonnation. The affidavit sets forth the basis on which the infonnation may be withheld from public disclosure by the Commission and addresses with specificity the considerations listed in paragmph (b)(4) of 10 CFR Section 2.790 of the Commission's regulations.
Accordingly, it is respectfully requested that the infonnation which is proprietary to Westinghouse be withheld from public disclosure in accordance with 10 CFR Section 2.790 i
of the Commission's regulations.
Correspondence with respect to the copyright or proprietary aspects of the items listed above or the supporting Westinghouse Affidavit should reference CAW-93-458 and should be addressed to N. J. Lipamlo, Manager of Nuclear Safety and Regulatory Activities, Westinghouse Electric Corpontion, P.O. Box 355, Pittsburgh, Pennsylvania 15230-0355.
In addition, enclosed is the Catawba SLB dose analysis engineering calculation and results which utilize the values for SLB steam genemtor tube leakage given in the enclosed WCAP.
4 I declare under penalty of perjury that these statements are true and correct to the best of my knowledge.
Very truly yours,
[ MN M. S. Tuckman Enclosures
E Nuclear Regulatory. Commission April 29,1993 Page 3 xc: Mr. S. D. Ebneter Regional Administator, Region II U. S. Nuclear Regulatory Commission 101 Marietta Street, NW, Suite 2900 Atlanta, GA 30323 Mr. Heyward Shealy, Chief Bureau of Radiological Health South Carolina Depanment of Health &
Environmental Control 2600 Bull Street Columbia, SC 29201 Mr. W. T. Orders NRC Resident Inspector Catawba Nuclear Station Mr. Roben E. Martin, Project Manager ONRR Mr. William T. Russell, Associate Director Inspection & Technical Assessment ONRR American Nuclear Insurers c/o Dottie Sherman, ANI Library
. The Exchange, Suite 245 270 Farmington Avenue Fannington, CT 06032 M & M Nuclear Consultants 1166 Avenue of the Americas New York, NY 10036-2774 INPO Records Center Suite 1500 1100 Circle 75 Parkway Atlanta, Georgia 30339 i
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U. S. Nuclear Regulatory Commission April 29,1993 Page 4 bxc: D. B. Mayes W. A. Haller H. D. Brewer l
T. E. Cook R. C. Futrell T. P. Harrall A. S. Bhatnager R. O. Sharpe D. V. Ethington T. C. Poindexter L. R. Davison NCMPA-1 NCEMC PMPA SREC ELL-EC050 Group File: CN-801.01 Master File: 801.01
- )