ML19331E414
| ML19331E414 | |
| Person / Time | |
|---|---|
| Site: | Peach Bottom  |
| Issue date: | 08/08/1980 |
| From: | Daltroff S PECO ENERGY CO., (FORMERLY PHILADELPHIA ELECTRIC |
| To: | Grier B NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I) |
| References | |
| IEB-80-17, NUDOCS 8009100121 | |
| Download: ML19331E414 (3) | |
Text
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PHILADELPHIA ELECTRIC COMPANY 2301 M ARKET STRETT P.O. BOX 8699 PHILADELPHI A. PA.19101 SHIELDS L. DALTROFF stsc'in1c e'a'ob von August 8, 1980 Re: Docket Nos. 50-277 50-278 IE Bulletin 80-17 Mr. Boyce H.
Grier, Director Office of Inspection & Enforcement Region I US Nuclear Regulatory Commission 631 Park Avenue King of Prussia, PA 19406
Dear Mr. Grier:
This letter provides additional information with respect to item 6.c of our previous response to IE Bulletin 80-17, dated July 17, 1980, concerning the failure of 76 of 185 control rods to fully insert during a scram at a BWR.
The " Action tu 'ue Taken by Licensees" and our response follows.
Action to be Taken by Licensees 6.
In order to mitigate the consequences of an ATWS event, enhanced operability of HPCI, RCIC, SLCS, RPT/RHR/ pool cooling and main steam bypass is essential.
Accordingly, the following actions are requested:
c.
Perform a 50.59 review to increase SLCS flow to the maximum consistent with safety (2 pumps, inniess unsafe).
Response
We have concluded our 50.59 review to determine the capability of Peach Botton Units 2 and 3 to increase the Standby Liquid Control System (SLCS) injection flow by operating two pumps.
.8009100 82I
Mr. Beyco H.
Grior Pega 2 The final results of the review are as follows:
1)
The SLCS pump discharge piping and components are adequate for two pump operation.
2)
Section 3.8.3 of the FSAR (SLCS Description) describes an injection time of 50 to 125 minutes for one pump operation.
The minimum injection time cannot be complied with since two pump operation results in a 100 gpm flow rate and an injection time of less than 50 minutes.
The safety significance of the minimum injection time (i.e. maximum injection rate) is explained in Section 3.8.4 of the FSAR (SLCS Safety Evaluation) which states
"...The upper limit injection rate assures that there is sufficient mixi.ig so the boron does not recirculate through the core in uneven concentrations which could possibly cause the nuclear power to rise and fall cyclically".
3)
The electrical circuitry for the SLCS pumps does not permit simultaneous two pump operation.
4)
The calculations performed to determine the adequacy of the SLCS pump suction piping indicate that the piping would not provide adequate NPSH for two pump operation.
Based on items 2 and 4 above, it has been concluded that the simultaneous operation of two SLCS pumps without implementing changes constitutes an unreviewed safety question.
Should you have any questions or require additional information, please do not hesitate to contact us.
Very truly yours,
,{
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lI cc: US Nuclear Regulatory Commission Office of Inspection & Enforcement Division of Reactor Operations Inspection Washington, DC 20555
COMMONWEALTH OF PENNSYLVANIA :
ss.
COUNTY OF PHILADELPHIA S.
L. Daltroff, being first duly sworn, deposes and says:
That he is Vice President of Philadelphia Electric Company; that he has read the foregoing response to IE Bulletin 80-17 and knows the contents thereof; and that the statements and matters set forth therein are true and correct to the best cf his knowledge, information and belief.
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Subscribed and sworn to before me this ll day
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