ML20072S759

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Proposed Tech Spec Change 115 Re Operability of Isolation Condenser Isolation Valves to Clarify Existing Specs & to Permit out-of-svc Time for Maint While Intended Valve Function Maintained
ML20072S759
Person / Time
Site: Oyster Creek
Issue date: 03/31/1983
From:
GENERAL PUBLIC UTILITIES CORP.
To:
Shared Package
ML20072S736 List:
References
NUDOCS 8304070327
Download: ML20072S759 (7)


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r GPU NUCLEAR CORPORATION OYSTER CREEK NUCLEAR GENERATING STATION DOCKET No. 50-219 PROVISIONAL OPERATING LICENSE No. DPR-16 Applicant hereby requests the Commission to change Appendi A Technical Specifications to the above captioned license as follows:

1. Section to be changed:

Appendix A, Section 3.1, Table 3.1.1, Item H, pages 3.1-10 and 3.1-14 Appendix A, Section 3.8, pages 3.8-1 and 3.8-2

2. Extent of change:

This change is requested to clarify the existing specifications regarding isolation condenser isolation valve operability. A note to Table 3.1.1, Item H of Section 3.1 addresses valve operability and references limiting i conditions for operation incorporated into Section 3.8. No specifications (3.8.E and 3.8.F) are added to Section 3.8 which limit out of service times for isolation condenser isolation valves to a maximum of 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br />, except for the normally-closed DC motor-operated outlet (condensate' return) line valve. An addition to the Bases of Section 3.8 is included, which discusses Specifications 3.8.E and 3.8.F.

! 3. Changes requested:

Requested changes are as indicated on the attached revised Appendix A Technical Specification pages.

4. Discussion:

The specifications which determine the operability of the isolation condensers and associated components are not specific as regards the t, operability of isolation condenser isolation valves. It is the intention of GPU Nuclear to clarify this situation by incorporating into Technical l

Specifications additional specifications which provide limiting conditions

! for operation relative to the isolation condenser isolation valves.

A note to Table 3.1.1. , Item H of Section 3.1 " Protective Instrumentation" will be added to address isolation condenser isolation valve operability.

This note references limiting conditions for operation added to Section 3.8 " Isolation Condenser". Specification 3.8.E is proposed to allow a 1 maximum out of service time of four hours for an isolation condenser inlet (steam side) isolation valve providing the redundant valve is tested operable. Specification 3.8.F is proposed to allow a four hour out of service time for the AC motor-operated outlet isolation valve located within the drywell.

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An operability check on the redundant DC motor-operated outlet valve is not necessary as this valve is normally closed and is operability tested once a month together with the other isolation valves, vent valves and i condensate (to condenser shell side) make-up valve. Inoperability of the normally closed DC outlet valve renders the isolation condenser inoperable as this valve will open on an initiation signal. For this reason an allowable out of service time for the DC outlet valve is not appropriate.

I The primary purpose for requesting this Technical Specification change is 4

to permit routine maintenance, such as valve steam packing addition or replacement, of the steam side isolation valves to be performed during reactor operation while maintaining the af facted isolation condenser operable to perform its intended function, if required. Analysis has shown a slight benefit, from a core melt risk standpoint, by maintaining 1 both isolation condensers operable during those periods projected for

- routine valve maintenance. Negligible increase in core melt risk due to a failure to isolate an isolation condenser has also been shown.

Presently, interpretation of current Technical Specifications applicable to the isolation condensers and their isolation subsystem requires operability of all four isolation condenser isolation valves in order to consider that isolation condenser operable. This requires the isolation condenser to be declared inoperable and isolated, subsequent to an operability check of the redundant condenser, before valve maintenance activity can proceed. A secondary benefit derived from the requested change is the reduction in the number of times the isolation condenser .

valves will be cycled, as they are normally surveilled once a month.

The maximum out of service time of four hours is chosen to be consistent with that permitted for primary containment isolation valves.

In conclusion, the proposed Technical Specification change will not result in a loss of function, only a reduction in redundancy, for short periods.

Reasonable p.asurrance of isolation capability is provided.

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! 3.1-10 I

TABLE 3.1.1 PROTECTIVE INSTRUMENTATION REQUIREMENTS (Continued) i Min. No. of Reactor Modes Min. No. of Ope rable in Which Function Operable or Instrument Must be Operable Operating Channels Per (Tripped) Trip Operable Action Fu nction Trip Setting Shutdown Re fuel Startup Run Systems Trip Systems Require d*

2. Inw-Low-Low 14'8" above X(v) X(v) X(v) X 2 2 See note h Reactor Water top of Level active fuel
3. AC Voltage NA X(v) X 2 . 2 Prevent auto depressurization on loss of AC power. See note i H. Isolation Condenser Isolation
1. High Flow Steam S20psig P X(s) X(s) X X 2 2 Isolate Affected Line isolation con-
2. High Flow Con- 127" P H0 X(s) X(s) X X 2 2 denser, comply densate line with Spec. 3.8 See Note cc l
1. Of f gas System Isolation Isolate reactor 1.High Radiation $10 x Stack X(s) X(s) X X 1 2 or trip the In Of f gas Line Release limit Inoperable in-(e) (See 3.6-A.1) strument channel J. Reactor Building Isolation and Isolate Reactor Standby Cas Treatment System Bldg. & Initiate Initiation ,

Standby Cas Treat-

1. High Radiation 1100 Mr/Hr X(w) X(w) X 1 1 ment System, or Reactor Building Manual Surveill-Operation Floor ance for not more
2. Reactor Bldg. 117 Mr/Hr X(w) X(w) X X 1 1 than 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> Ventilation (total for all In-Exhaust struments under
3. High Drywell $2 psig X(u) X(u) X X 1(k) 2(k) J) In any 30-day Pressure period
4. Low Low Reactor 17 ' 2" a bove X X X X 1 . 2

, Water Level top of i active fuel Change No. / Amendment No. g

3.1-14 k

i TABLE 3.1.1 (Cont 'd)

v. These functions not required to be operable when the ADS is not required to be operable.
w. These functions must be operable only when irradiated fuel is in the fuel pool or reactor vessel and secondary containment integrity is required per specification 3.5.B.
y. The number of operable channels may be reduced to 2 per Specification 3.9-E and F.
z. The bypass function to permit scram reset in the shutdown or refuel mode with control rod block must be operable in this mode. -

sa. Pump circuit breakers will be tripped in 10 seconds + 15% during a LOCA by relays SK7A and SK8A.

bb. Pump circuit breakers will trip instantaneously during a LOCA.

ec. If an isolation condenser inlet (steam side) isolation valve becomes or is made inoperable in the open position during the run mode comply with Specification 3.8.E. If an AC motor-operated outlet (condensate return) isolation valve becomes or is made inoperable in the open position during the run mode comply with Specification 3.8.F. -

Amendment No. X M .Mr

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3.8-1 3.8 ISOLATION CONDENSER Applicability: Applies to operating status of the isolation condenser.

Objective: To assure heat removal capability under conditions of reactor vessel isolation from its normal heat sink.

Specification: A. The two isolation condenser loops shall be operable during power operation and whenever the reactor coolant temperature is greater than 212 0F except as specified in C, below. -

B. The shell side of each condenser shall contain a minimum water volume of 22,730 gallons. If the minimum volume cannot be maintained or if a source of makeup water is not available to the condenser, the condenser shall be considered inoperable.

C. If one isolation condenser becomes inoperable during the run mode the reactor may remain in operation for a period not to exceed 7 days provided the motor operated isolation

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and condensate makeup valves in the operable isolation condenser are demonstrated daily to be operable.

D. If Specification 3.8. A and 3.8.B are not met, or if an inoperable isolation condenser cannot be repaired within 7 days, the reactor shall be placed in the cold shutdown condition.

E. If an isolation condenser inlet (steam side) isolation valve (V-14-30, 31, 32 or 33) becomes or is made inoperable, in the open position during the run mode, the redundant inlet isolation valve shall be demonstrated operable. If the inoperable valve is not returned to service within 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> declare the af fected isolation condenser inoperable, isolate it and comply with Specification 3.8.C.

F. If an AC motor-operated isolation condenser outlet (condensate return) isolation valve (V-14-36 or 37) becomes or is made inoperable in the open position in the run mode, return the valve to service within 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> or declare the af facted isolation condenser inoperable, isolate it and comply with Specification 3.8.C.

Amendment No.

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. 3.8-2 Basi s: The purpose of the isolation condenser is to depressurize the reactor and to remove reactor decay heat in the event that the turbine generator and main condenser is unavailable as a heat sink.(1) Since the shell side of the isolation condensers operate at atmospheric pressure, they can accomplish their purpose when the reactor temperature is suf ficiently above 2120F to provide for the heat transfer corresponding to reactor decay heat. The tube side of the isolation condensers form a closed loop with the reactor vessel and can operate without reducing the reactor coolant water inventory.

Each condenser containing a minimum total vater volume of 22,730 gallons provides 11,060 gallons above the condensing tubes.

- Based on scram f rom a reactor power level of 1950 MWt (the design basis power level for the isolation condensers) the condenser system can accommodate the reactor decay heat (2,3)

(corrected for U-239 and NP-239) for 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> and 40 minutes without need for makeup water. One condenser with a minimum water volume of 22,730 gallons can accommodate the reactor decay heat for 45 minutes af ter scram f rom 1950 MWt before makeup water is required. In order to accommodate a scram from 1950 MWt and cooldown, a total of 107,500 gallons of makeup water would be required either from the condensate storage tank or from the fire protection system. Since the rated reactor power

, is 1930 MWt,the above calculations represent conservative estimates of the isolation condenser system capability.

The vent lines from each of the isolation condenser loops to the main steam lines downstream of the main steam lines isolation valves are provided with isolation valves which close automatically on isolation condenser actuation or on signals which close the main steam isolation valves. Radiation monitors on the condenser shell side vents and the associated alarms in the control room are provided to alert the operator of a tube leak in the isolation condenser. High temperature sensors in i the isolation condenser and pipe areas cause alarm in the control room to alert the operator of a piping leak in these areas.

Specification 3.8.E allows reduction in redundancy of isolation capability for isolation condenser inlet (steam side) isolation

' valve s. Reasonable assurrance of isolation capability is provided by testing the operability of the redundant valve.

Specification 3.8.F allows short term inoperability of the AC motor-operated isolation condenser outlet (condensate return) valve. It is not necessary to test the redundant DC motor-operated valve as this valve is normally in the closed position. These specifications permit troubleshooting and j repair as well as routine maintenance, such as valve stem packing addition or replacement, to be performed during reactor

! operation without reducing the redundancy of the isolation condenser heat sink function. The out of service time of 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> is consistent with that permitted for primary containment isolation valves. (5)

Amendment No.

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- 3. 8-3 Either of the two isolation condensers can accomplish the purpose of the system. If one condenser is found to be inoperable, there is no immediate threat to the heat removal capability for the reactor and reactor operation may continue while repairs are being made.

Therefore, the time out of service for one of the condensers is based l on considerations for a one out of two system.(4) The test interval for operability of the valves required to place the isolation condenser in operation is once/ month (Specification 4.8). An I acceptable out of service time, T, is then determined to be 10 days.

However,1f at the time the failure is discovered and the repair time is longer than 7 days the reactor will be placed in the cold shutdown i

condition. If the repair time is no more than 7 days the reactor may I continue in operation, but as an added factor of conservatism, the motor operated isolation condenser and condensate makeup valves on the operable isolation condenser are tested daily. Expiration of the 7 day period or inability to meet the other specifications requires that the reactor be placed in the cold shutdown condition which is normally expected to take no more than 18 hours2.083333e-4 days <br />0.005 hours <br />2.97619e-5 weeks <br />6.849e-6 months <br />. The out of service allowance when the system is required is limited to the run mode in order to require system availability, including redundancy, at st art up .

i Refere nce s:

(1) FDSAR, Volume I, Section IV-3.

(2) K. Shure and D.J. Dudziak, " Calculating Energy Release by Fission Products", U.S. AEC Report, WAPD-T-1309, March 1961.

(3) K. Shure, " Fission Product Decay Heat", in U.S. AEC Report , WAPD-BT-24, December 1961.

(4) Specification 3.2, Bases.

(5) Specification 3.5.3.a.1. I Amendment To.

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