ML19294C237
| ML19294C237 | |
| Person / Time | |
|---|---|
| Site: | FitzPatrick  |
| Issue date: | 02/29/1980 |
| From: | Early P POWER AUTHORITY OF THE STATE OF NEW YORK (NEW YORK |
| To: | Ippolito T Office of Nuclear Reactor Regulation |
| References | |
| JPN-80-14, NUDOCS 8003070356 | |
| Download: ML19294C237 (3) | |
Text
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POWER AUTHORITY OF THE STATE OF NEW YORK 10 CoLUMaus CIRCLE NEW YORK. N. Y.1oo19 (2f21 397.6200 G EORG,E T. B ER RY op.e A Y 4 hG CFFICIA JOHN W BOSTON JOHN S.DYSON Pm o
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GEORGE L. ING ALLS JOSEPH R. SCHMIEDER vaca Csea#nesAM
- s. ca a cwigr RICH ARD M. FLYNN LEROY W SIN C LAIR Ro. err i MiLLoan February 29, 1980
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Director of Nuclear Reactor Regulation U.
S. Nuclear Regulatory Commission Washington, D.
C.
20555 Attention:
Mr. Thomas A.
Ippolito, Chief Operating Reactcrs Branch No. 3 Division of Operating Reactors
Subject:
James A. FitzPatrick Nuclear Power Plant Docket No. 50-333 Containment Purging and Venting During Normal Operation
Reference:
Letter, Thomas A.
Ippolito (NRC) to George T.
Berry (PASNY) dated October 22, 1979
Dear Sir:
The following is the response to the NRC " Interim Position for Containment Purge and Vent Valve Operation Pending Resolution of Isolation Valve Operability" which is an attachment to the reference letter.
NRC Condition 1 Whenever the containment integrity is required, emphasis should be placed on operating the containment in a passive mode as much as possible and on limiting all purging and venting times to as low as achievable.
To justify venting or purging, there must be an established need to improve working conditions to perform a safety related surveillance or safety related maintenance procedure.
(Examples of improved working conditions would include deinerting, reducing temperature, humidity, and airborne activity sufficiently to permit efficient performance or to significantly reduce occupat-ional radiation exposures), and
Response
The Authority's letter of August 15, 1979 provided a description of uses for the Containment Purge and Vent System.
These uses have been modified as follows:
A034 1.
The Authority will continue to meet the requirements of 5
ll0 8003070 %4 6
\\ Technical Specification (TS)' Section 4.7. A.5a requiring cycling of the pressure suppression chamber-drywell vacuum breakers monthly.
This will now be accomplished by (1) equalizing the pressure between the suppression chamber and drywell by opening the outboard drywell exhaust isolation valve and the bypass valve (2 inch) around the inboard drywell exhaust isolation valve, (2) exercising the vacuum breakers, and (3) closing the valves mentioned above and repressurizing the drywell using the nitrogen Make-up (C. A. D. ) System.
This procedure necessitates opening only one large (24 inch) isolation valve which b protected from significant pressure drops in the event of a LOCA by the 2 inch bypass line.
2.
Control of containment pressure and maintenance of the required differential pressure between the drywell and the suppression chamber are by use of the Make-up (C.A.D.) System for make-up and by use of the suppression chamber exhaust line to the SBGT System for exhaust.
3.
The Authority will minimize the time required for deinercing and inerting during reactor power operation or hot shutdown by conducting these operations as quickly as possible and only when visual inspection of the reactor coolant pressure boundary is merited.
Inerting and deinerting will be done using the suppression chamber supply line and the drywell exhaust line.
4.
The purge and vent system is not used for humidity, temperature or airborne activity control during reactor power operation er hot shutdown conditions.
NRC Condition 2 Maintain the containment purge and vent isolation valves closed whenever the reactor is not in the cold shutdown or refueling mode until such time as you can show that:
All isolation valves greater than 3" nominal diameter used for a.
containment purge and venting operations are operable under the most severe design basis accident flow condition loading and can close within the time limit stated in your Technical Specifications, design criteria or operating procedures.
The operability of butterfly valves may, on an interim basis, be demonstrated by limiting the valve to be no more than 300 to open (90 being full open).
The maximum opening shall be 500 determined consultation with the valve supplier.
The valve opening must be such that the critical valve parts will not be damaged by DBA-LOCA loads and that the valve will tend to close when the fluid dynamic forces are introduced, and
.s I
_3 b.
Modifications, as necessary, have been made to segregate the containment ventilation isolation signals to ensure that, as a minimum, at least one of the automatic safety injection actuation signals is uninhibited and operable to initiate valve closure when any other isolation signal may be blocked, reset, or overridden.
Response to 2.a The Authority has requested from the purge and vent system isolation valves vendor an assessment of the ability of these valves to close against DBA-LOCA loads using guidelines provided to the Authority by the NRC in its letter of September 27, 1979.
Recommendations on valve travel limitations have been requested from the valve vendor and were received orally on February 28, 1980.
Analyses performed by the vendor assumed that the total LOCA containment pressures six seconds after the LOCA were seen across each isolatio:
'.ve throughout their travel from fully open to closed.
The maalyses indicated that na limitation is required for either the 20 inch valves in lines from the suppression chamber or for the 24 inch valves in lines from the drywell.
Consideration was given to LOCA induced stresses in valve parts, and the ability of valve operators to overcome resisting torque.
Response to 2.b Resetting of any isolation signal to the containment vent and purge system will not reset any other isolation signal.
Until the NRC concerns relative to the logic for isolation signal override discussed in the Authority's letter of August 15, 1979 have been resolved, the Authority will not use the Emergency Manual Override without prior NRC approval.
Very truly_your,s,
')N'i
/./.Y;'..
Paul J. Early Assi,stant Chief Engineer-Projects
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