ML20009B185
| ML20009B185 | |
| Person / Time | |
|---|---|
| Site: | Peach Bottom  |
| Issue date: | 07/10/1981 |
| From: | Daltroff S PECO ENERGY CO., (FORMERLY PHILADELPHIA ELECTRIC |
| To: | Novak T Office of Nuclear Reactor Regulation |
| References | |
| RTR-NUREG-0619, RTR-NUREG-619 NUDOCS 8107150019 | |
| Download: ML20009B185 (3) | |
Text
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PHILADELPHIA ELECTRIC COMPANY
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P.O. BOX 8699 1881 -1981 PHILADELPHIA. PA.19101
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July 10, 1981 N
Re: Docket Nos. 50-277 50-278 Mr. Thomas M. Novak Assistant Director for Operating Reactors Division of Licensing U.S.
Nuclear Regulatcry Commission Washington, DC 20555
Dear Mr. Novak:
Your letter of June 10, 1981, expressed concern over the use of filter systems in the control rod drive hydraulic system (NUREG-0619).
In addition, the letter, as quoted below, requested further information regarding the proposed modifications to the CRD system.
"You have stated that replacement of carbon steel pipe in the flow stabilizer loop is not necessary because of the particular existing system configuration incorporating filters.
Our objection to the use of filter systems is contained on page D-6 of NUREG-0619.
Please provide justification for continued use of the filters, including ninimum particle size, alarm setpoint, location of alarm, procedural changes to incorporate filter maintenance, etc."
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Response
We have reviewed the NRC concerr over the use of filters in the CRD system, as expressed in NUREG 0619, Appendix D, and conclude that the existing modification is acceptable.
The concern is tnat improperly maintained filters on the cooling D\\
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Mr. Thomac M.
NovCk Page 2 water header could result in heatup of drive mechanisms and the possibility of multiple drive failures of a type not previously analyzed.
The redundant filters installed per General Electric's recommendation in SIL-200, Rev 1, prevent any carbon steel corrosion products from re-entering the flow stream to the drives via the cooling water headers.
The filters are not in the primary path for the cooling water to the CRD's,"and therefore cannot restrict the cooling water flow to the CRD's.
The attached sketch demonstrates the location of the filters with respect to the main cooling flow and the stabilizing valves.
The filters selected and installed are 50 micron absolute (20 micron nominal) units, equipped with differential pressure alarms set at 5 psi that indicate high filter pressure in the control room.
No procedural changes to the normal maintenance of these filters is anticipated.
We trust this satisfies the reviewer's concern and hastens approval of this modification.
Very truly yours, J
..- A Attachment
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-e CAPPED NOZZLE REACTOR V ESSEL OMIV E WATER (WITHDR AW) s A
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ORIVE W ATER lp.
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2k 122 122 SCRAM SCRAM dL g
VALVE DISCHARGE
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BOUNDARY ausmC>
8 VALVE N, 4
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0 2
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120 121 DIRECTIONAL g
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L CONTROL SOLENOIO H OE
.~7 VALVE EXH AUST WATER OTHER,
OTHER '
COOLING WATER q
OTHER ORIVE C11 F150A l
ORtVE g
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RO WATER g
I CHARGING MO WATER SYSTEM 8
C11-F1508 1
FCv l
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NEW EQUALIZINC VALVES _ _ _ _j C"
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3 sTAnni. 'ING U
t,agno VALv
- NORMAL FLOW P AT)
1' il g REvtNsE FLOW OISPERSAL g
OF EXHAUST N
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+ N Filter Modification stabilizirg flow
,p onIv thru filters Simplified Scherruts,: of Modified CR0 Hydraulic System l
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