ML20042B756
| ML20042B756 | |
| Person / Time | |
|---|---|
| Site: | FitzPatrick  |
| Issue date: | 03/19/1982 |
| From: | Bayne J POWER AUTHORITY OF THE STATE OF NEW YORK (NEW YORK |
| To: | Vassallo D Office of Nuclear Reactor Regulation |
| References | |
| RTR-NUREG-0737, RTR-NUREG-737, TASK-2.B.1, TASK-TM JPN-82-31, NUDOCS 8203250623 | |
| Download: ML20042B756 (3) | |
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k POWER AUTHORITY OF THE STATE OF NEW YORK 10 CoLUMeus CIRCLE NEW YORK. N. Y.10019 t212) 397 620o GEORGET. BERRY en Sion=v e Cuiar opanatino orr Can TRUSTEES JOHN S DYSON E ECUT WE V CE CHaseMAN PRESIDENTWROC EDW AES aPERFoRelANCE JOSEPH R. SCHMIEDER v CE CMale A Pat ids a CMIEF RICH ARD M. FLYNN ENGihEta ROSERT 4. MILLON2B LEROY W. SINCLAIR March 19, 1982
<~ica vics passica~r JPN-82-31
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FREoERicic R. Ci.4 R x THOM AS R FREY SENIOR viCE Pat SID 'NT Director of Nuclear Reactor Regulation U. S. Nuclear Regulatory Commission fo Washington, D. C.
20055 P
4 RECEi'MD Attention:
Mr. Domenic B. Vassallo Operating Reactors Branch No. 2 N 2 5 M-3 Division of Licensing N REDIEUR3 2hein C1EE Kr,M2ggg Subj ect:
James A. FitzPatrick Nuclear Power Plant N
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Docket No. 50-333 Reactor Coolant System Vents 4
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NUREG-0737 Item II.B.1 Re ferences :
1.
NRC letter, D. B. Vassallo to G. T. Berry, dated January 26, 1982 2.
PASNY letter, J. P. Bayne to T. A. Ippolito, dated January 11, 1982 (JPN-8 2-7 ).
Dear Sir Reference 1 requested additional information concerning the capability for venting the FitzPatrick reactor coolant system and emergency core cooling systems following a postulated accident. The questions asked in this letter are restated below and followed by the Power Authority's response.
1.
Question Identify any systems or equipment containing high points which may need venting (for example, the RHR heat exchanger) to maintain adequate core cooling. Describe the methods and indications used to identify the need to vent, the equipment used to vent, and vent flow path, and discharge area of each of the above identified vents.
Response
The only two systems which could require venting to maintain post-accident core cooling are the Reactor Coolant System (RCS) and the Residual Heat Removal (RHR) System. The Power Authority has provided information on RCS venting in several previous subnittals to the NFC.
This information is summarized in Reference 2.
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. The Ri!R system is designed for several different modes of operation including the condensing mode.
In this mode, the reactor is isolated from the main condenser and steam condensing is accomplished in the RHR heat exchanger.
Since the non-condensible gases would tend to accumulate in the heat exchanger, the system design includes the capability for venting.
Venting is accomplished through two safety related motor operated valves, which are installed in series and operated from the control room.
The vent line discharges to the suppression pool. Operating procedures provide the operator with guidance for venting the heat exchanger to prevent the accumulation of non-condensible gases.
2.
Question If it were necessary to use the reactor vessel head vents in order to maintain adequate core cooling post-LOCA, discuss the guidelines the operator would follow to use these vents including:
a)
When to vent or not vent considering combustible gas concentration in containment.
b)
Potential single failures in the vent path, including the failure of a valve to close.
c)
The effect of vent discharge on surrounding equipment.
Response
a)
RCS venting is normally accomplished by the safety relief valves which open automatically, or by operator action in the control room.
Venting might also occur through the postulated break.
The Containment Atmosphere Dilution (CAD) System is designed on the assumption that the RCS is continuously vented following a postulated accident. The procedure for post-LOCA venting of the containment provides specific and detailed guidance to the operator for controlling oxygen and combustible gas concentrations in containment. This procedure applies regardless of whether the RCS is vented through the postulated break, the safety relief valves, or the reactor vessel head vent valves.
b)
The reactor vessel head vent line is equipped with two air operated valves in series which are operated from the control room.
Failure of one valve to open is of no consequence since venting can be accomplished with the safety relief valves. Since the two valves are in series, failure of one to close will not result in continous venting.
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The head vent line is piped to the drywell. equipment sump.
Therefore, vent discharges will not affect equipment.
If you'have any further questions, please do not hesitate to contact us.
Very truly yours, T
P Bayne Se r Vice President Nuclear Generation cc: Mr. J. Linville Resident Inspector -
U.S. Nuclear Regulatory Commission P.O. Box 13 6 Lycoming, New York 13093 Mr. Ron Barton I
United Engineers & Constructors, Inc.
I 30 S. 17th Street Philadephia, Pa.
19101 i
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