ML19318D093
| ML19318D093 | |
| Person / Time | |
|---|---|
| Site: | Wolf Creek, Callaway, Sterling  |
| Issue date: | 06/30/1980 |
| From: | Petrick N STANDARDIZED NUCLEAR UNIT POWER PLANT SYSTEM |
| To: | |
| References | |
| SLNRC-80-32, NUDOCS 8007070325 | |
| Download: ML19318D093 (1) | |
Text
SNUPPS Standardized Nucteet Unit Power Plant System 5 Choke Cherry Road Nicholas A. Petrick R
v tie Ma land 20850 Executive Director June 30, 1980 SLNRC 80- 32 FILE: 0491.10.2 SUBJ: Postulated Feedwater Line Piping Break Mr. Boyce Grier Director, Region I U.S. Nuclear Regulatory Commission 631 Park Avenue King of Prussia, Pennsylvania 19406 Docket Nos. STN 50-482, STN 50-483, STN-485, STN 50-486
Dear Mr. Grier:
On June 2, 1980, SNUPPS informed the Nuclear Regulatory Commission, Region I Office of Inspection and Enforcement, of a potential deficiency involving excessive pressures in feedwater lines following a postulated high energy line break. The information was communicated by telephone to Mr. Richard McGaughy of your staff pursuant to 10CFR50.55(e).
For a postulated feedwater line break in the turbine building of a SNUPPS plant, Bechtel has calculated a peak pressure of approximately 4000 psi in the feedwater lines between the steam generator and the feedwater check valve, following closure of the check valves which are located just outside containment. This pressure has been evaluated to be unacceptably high. The peak pressure in the feedwater lines for this transient can be reduced by relocating the feedwater check valves inside containment, closer to the steam generators. This change is being evaluated by SNUPPS, Bechtel, and Westinghouse.
The excessive pressure described above was discovered during the high energy line break analysis which is performed late in the design process after exact piping layout and support have been determined.
It is considered part of nor-mal design evolution that potential problems such as this one are discovered and corrected. Therefore SNUPPS does not consider this matter to be report-able under 10CFR50.55(e). Any design, description, or analysis change that is required because of this feedwater line break consideration will be re-flected in a revision to the SNUPPS FSAR.
Ver truly yours, 30/7
/
R-Wsc d
Nicholas A. Petri
/O RLS/dck/Bla3 se:
Mr. James G. Keppler, Director, Region III, USNRC
\\ r. Karl V. Seyfrit, Director, Region IV, USNRC M
Mr. Victor Stello, Jr., Director, office of Ist, usiaC 8007070 M
.