ML19254D903
| ML19254D903 | |
| Person / Time | |
|---|---|
| Site: | Peach Bottom  |
| Issue date: | 10/25/1979 |
| From: | Gallagher J PECO ENERGY CO., (FORMERLY PHILADELPHIA ELECTRIC |
| To: | Eisenhut D Office of Nuclear Reactor Regulation |
| References | |
| NUDOCS 7910300303 | |
| Download: ML19254D903 (2) | |
Text
- ,,r PHILADELPHIA ELECTRIC COMPANY 2301 MARKET STREET P.O. BOX 8699 PHILADELPHIA. PA.19101 JOSEPH W. GALLAGHER stactnic enooucv o'ee onpantasan, 1215)841 5003 October 25, 1979 Docket Nos-50-277 50-273 Mr. Darrell G.
Eisenhut, Acting Director Division of Operating Reactors U.S.
Nuclear Regulatory Commission Washington, DC 20555 Dear Mr. Eisenhut This is in resoonse to your letter to E. G.
- Bauer, Jr.,
dated September 27, 1979 on the subject of " Containment Purging and Venting During Normal Operation Guidelines for Valve Operability." This general topic was discussed at a meeting with your staff on August 24 1979.
Subsequent to that meeting, we began a dialogue with our architect-engineer and valve manufacturers in order to address the relevant issues in a timely manner.
In accordance with your request, we will complete our analysis of the operability of the butterfly valves used for isolation of the large diameter purge and vent valves at Peach Bottom in an expeditious manner.
Because of the detailed work
- required, i.e.
evaluation of piping geometries and their affects on the operability of these valves, we anticipate completion of this work by April 30, 1980.
Analyses will be performed to demonstrate that these valves will close against post-LOCA pressures (f rom a preset partially open position) within the time limit specified, considering those factors listed in the enclosure t o your letter which are relevant.
Sealing integrity after closure and long term exposure to the post-LOCA containment environment will also be addressed.
No bench or insitu testing is p rop os ed, since we will meet all of the criteria for operability by analyses in accordance with the enclosure of your letter.
Depending on the results of these analyses, appropriate corrective actions (modifications or revised operating procedures) will be developed and imp leme s ced.
1
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7 9103 00.3 0 N P
Mr.
D.
G.
Eisenhut Page 2 Performing an analyses on the 1" air-operated globe valves used for isolation of the small diameter purge and vent lines is unnecessery.
These valves have been designed and cesced for rapid closure against pressures significantly higher than they would experience following a LOCA.
The valves in the drywell purge lines have been deaonstrated to close in less than 5 seconds against a dif f erential p ressure of 1135 psig, and those on the torus against 110 psig.
These are substantially greater than the maximum post-LOCA pressures of 42 psig in the drywell and 26 psig in the torus (see FSAR Figure 14.6.10).
A seismic analysis of these "small" purge valves has recently been completed and with satisfactory results.
The stainless steel seating surfaces of these valves will not be subject to degradation when exposed to a post-accident environment.
Very truly yours,
)h 4J 1, i. '.n 2
c s.,,
-