ML20207N276
| ML20207N276 | |
| Person / Time | |
|---|---|
| Site: | Grand Gulf  |
| Issue date: | 01/12/1987 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML20207N254 | List: |
| References | |
| TAC-62963, NUDOCS 8701140092 | |
| Download: ML20207N276 (1) | |
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j,E wAsmNGTON, D. C. 20555 Enclosure
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SAFETY EVALUATION REPORT BY THE OFFICE OF NUCLEAR REACTOR REGULATION RELATING TO TRAIN B FEEDWATER CHECK VALVE REPLACEMENT FOR GRAND GULF NUCLEAR STATION, UNIT 1
1.0 INTRODUCTION
Section 6.2.8, " Fracture Prevention of Containment Pressure Boundary" of the Safety Evaluation Report (SER) for Grand Gulf Nuclear Station, (GGNS) issued in September, 1981 identified the licensee's commitment to replace feedwater check valve discs in cases where the lowest service metal temperature (LSMT) could fall below that permitted by the disc material's fracture toughness. This is also addressed in operating license condition 2.C(17).
2.0 EVALUATION By letter dated September 26, 1956, the licensee stated that the LSMT for Train B feedwater lines is 65'F and since the original Train B valve disc material had a nil-ductility transition temperature of 78'F, it has been replaced with a disc made of ASME SA351 CF8M stainless steel. The nil ductility transition temperature for ASME SA351 Grade CF8M is less 1
than 32"F. Since this is below the LSMT for Train B, fracture toughness concerns regarding this component are resolved.
In a September 1, 1981 letter the licensee stated that the Train A feed-water line has a LSMT which is acceptable for the disc associated with the' check valve. The LSMT for Train A is 80 F, and the nil-ductility transition temperature for the disc of the valve is below this temperature.
Therefore the disc was not replaced.
3.0 CONCLUSION
S Based on its review, the staff concludes that the licensee has fulfilled the commitment identif ?ed in the SER Section 6.2.8 and has satisfied the requirement of operating license condition 2.C.(17) by replacing the Train B feedwater check valve disc.
8701140092 870112 P
DR ADOCK 05000416 PDR
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