ML20235N505
| ML20235N505 | |
| Person / Time | |
|---|---|
| Site: | Comanche Peak  |
| Issue date: | 02/13/1989 |
| From: | William Cahill TEXAS UTILITIES ELECTRIC CO. (TU ELECTRIC) |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| CP-86-41, TXX-89058, NUDOCS 8903010254 | |
| Download: ML20235N505 (1) | |
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Log # TXX-89058
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9 File # 10110
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915.6 C
C Ref. # 10CFR50.55(e) 1UELECTRIC i
February 13, 1989 W.J.CahiH Executive Vice President U. S. Nuclear Regulatory Commission Attn: Document Control Desk Washington, D. C.
20555
SUBJECT:
COMANCHE PEAK STEAM ELECTRIC STATION (CPSES)
DOCKET NOS. 50-445 AND 50-446 SMALL BREAK LOCA MODE 4 OPERATION SDAR:
CP-86-41 (INTERIM REPORT)
Gentlemen:
On May 28, 1986, TV Electric verbally informed your Mr. I. Barnes of a deficiency involving the evaluation of the effect of a small break LOCA during Mode 4 operation. This is an interim report of a potentially reportable item under the provisions of 10CFR50.55(e). The most recent interim report was logged TXX-88603, dated August 10, 1988.
Following the NRC Regulatory Staff's decision not to accept the Westinghouse Owners Group (WOG) plan to apply Leak Before Break technology in resolving the issue of a small break LOCA during either Mode 3 or 4 operation, the WOG developed a new approach, identified in the interim report transmitted with TXX-88258, dated February 29, 1988.
The WOG approach includes three major project tasks, i.e., determination of the failure rate of large piping for Mode 3 and 4 conditions, comparison of core damage frequencies associated with a large LOCA in Mode 3 or 4 and Mode 1, and performance of a thermal-hydraulic analysis for a 6 inch pipe rupture to demonstrate that adequate time is available for the operator to assess the situation and activate the ECCS.
Each of these tasks has been completed and a report of the results is being prepared for submittal to the NRC.
TV Electric anticipates submitting its next report on this matter by August 14, 1989.
Sincerely, William J."Cahill, Jr.
RLA/ddm c - Mr. R. D. Martin, Region IV Resident Inspectors, CPSES (3) 8903010254 890213 p
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Vorth Olive Street LB81 Dallas, Texas 75201 I