ML20064A201

Proposed Tech Specs Re Core Spray Sys & Bases of Section 3.4

ML20064A201
Person / Time
Site:	Oyster Creek
Issue date:	08/14/1990
From:	GENERAL PUBLIC UTILITIES CORP.
To:
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ML20064A200	List: ML20064A199 ML20064A201
References
NUDOCS 9008270175
Download: ML20064A201 (8)

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.[ ' 3 .'4 EMERGENCY COOLING E Aoolicability: Applies to the operating status of the emergency cooling systems.

Obioetive: To assure operability of the emergency cooling systems.

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,SDecifications:

A .' Core Sorav System

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1. The core spray system shall be operable at all times with

' irradiated fuel in the reactor vessel, except as otherwise specified in this section.

2. The absorption chamber water volume shall be at least 82,000 ft.3 in order for the core spray system to be considered operable.'

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3. If one core spray system loop or its core spray header delta P instrumentation becomes inoperable during the run modo, the  !

reactor may remain in operation for a period not to exceed 7 days (See Note below) provided:

a. The remaining loop has no inoperable components and is demonstrated daily to be operable and, I

b. The average planar linear heat generation rate (APLHGR) of all the rods in any fuel assembly, as a function of average planar p

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exposure, at any axial location shall not exceed 90% of the

-limits given in Specification 3.10.A. The action to bring the core to 90% of the APLHGR Limits must be completed within two hours after_the system has been determined to be-inoperable.

4. The reactor may remain in operation for a period.not to exceed 15 days if one of the redundant active loop components in the core  !

j spray system becomes inoperable during the run mode provided:

a. In the event of an inoperable core spray booster pump, the other core spray booster pump in the loop is demonstrated '

daily to be operable.

b. In the event of an inoperable core spray main pump, the other core spray main pump in the loop is demonstrated daily to be p operable and the APLHGR of all the rods in any fuel asenmbly, as a' function of average planar exposure, at any axial location shall not exceed 90% of the limite given in Specification 3.10.A. The action to bring the core to 90% of the APLHGR Limits must be completed.within two hours after the component has been determined to be inoperable.

l NOTE: With the current ADS logic configuration, one inoperable core spray-

! loop defeats one ADS division. Therefore, the action required by Note L H, item G, Table 3.1.1 supercedes 3.4.A.3, and the reactor must be placed in cold shutdown condition within 30 hours3.472222e-4 days <br />0.00833 hours <br />4.960317e-5 weeks <br />1.1415e-5 months <br />. During 13R, a modification is planned which will eliminate the loss of an ADS Division concurrent with an inoperable Core Spray Loop. After the modification is completed, this note will no longer be applicable.

OYSTER = CREEK 3.4-1 Amendment No.: 75 9008270175 900814 L PDR ADOCK 0S000219 l P PDC

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If two of the redundant active loop components become  ;

E inoperable, the limits of Specification 3.4.A.3 shall apply.

E 5. -During the period when one. diesel is inoperable, the core spray equipment connected to the operable diesel shall be. operable.

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6. If Specificatione 3.4.A.3, 3.4.A.4, and 3.4.A.5 are not met, the reactor shall be placed in the cold shutdown condition. .If j the core spray system becomes inoperable, the reactor shall be placed in the cold shutdown condition and no work shall be 1 performed on the reactor or its connected systems which could i result in lowering the reactor water level to less than 4'8" l above the top of the active fuel.

7. If necessary to accomplish maintenance or modifications to the core spray systems, their power supplies or water suppliese reduced system availability is permitted when the reactor is l (a) maintained in the cold shutdown condition or (b) in the refuel mode with the reactor coolant system maintained at lwes  ;

than 212 P and vented, and (c) no work is performed on the reactor vessel and connected systems that could result in-lowering the reactor water level to less than 4'8" above the top of the active fuel. Reduced Core Spray System Availability is minimally defined as follows:

a. At least one core spray pump, and system componente necessary to deliver rated core spray.to the reactor vessel, must remain operable to the extent t'aat the pump and any necessary valves can be started or cperated from the control room or from local control stations,

b. The fire protection system is operable, and '

c. These systems are demonstrated to be operable on a weekly l basis.

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8. If necessary to accomplish maintenance or modifications to the .,

core spray' systems, their power supplies or water supplies, i l reduced system availability is permitted when the reactor is in the refuel mode with the reactor coolant system maintained at less than 2120 F or in the startup mode for the purposes of low power physics testing. Reduced core spray system availability is defined as follows:

a. At least one core spray pump in each loop, and system components necessary to deliver rated core spray to.the -

reactor vessel, must remain operable to the extent that the L

pump and any necessary valves in each loop can be started L or operated from the control room or from local control stations.

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b. The fire protection system is operable and, l

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c. Each core spray pump and all components in 3.4.A.8a are demonstrated to be operable every 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />.

OYSTER CREEK 3.4-2 Amendment No.: 75 l

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9.. If Spealficatiens-3.4'.A.7 cnd 3.4.A.8'cannat be' met, tho

. requirements of specification 3.4.A.6 will be met and work will

< be initiated to meet minimum operaoility requirements of-3 3.4.A.7 and 3.4.A.8.~ .;

10 .' The core spray system-is not required to be operable when the-following conditions are met:

'a.- The reactor mode switch-is locked in the " refuel" or ,

" shutdown" position.

b. -(l) There is an operable flow path capable of taking

• suction from the condensate storage tank and-transferring water to the reactor vessel, and l'

(2) The fire protection system is operable.

c. The reactor coolant system is maintained at less than 2120 F and vented (except during reactor vessel pressure testing).

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d. At least one core spray pump, and system components l' ,

necessary to deliver rated core spray flow to the. reactor vessel, must remain operable to the extent that the pump

(, and any necessary valves can be started or operv:ed from j the control room or from local control stations, and the torus is mechanically intact.

e. (1) No work shall be performed on the reactor or its  ;

connected systems which could result in lowering the L reactor water level to less than 4'8" above-the top of the active fuel and the condensate storage tank level is greater than thirty'(30) feet (360,000 gallons).1 At least two redundant systems including core spray j l

pumps and-system components must remain operable as l defined in d. above OR (2) The reactor vessel head, fuel pool gate, and separator-dryer pool gates are removed and the water-b level is above elevation 117 feet.

NOTE: When filling the reactor cavity from the ,

condensate storage tank and draining the reactor I cavity to the condensate storage tank, the 30 foot limit does not apply provided there is sufficient amount of water to complete the flooding operation. ,

l, D. Automatic Degggesurization Svetem i

1. Five electromatic relief valves of the automatic depressurization system nhall be operable when the res. tor water temperature is greater than 2120 F and pressurized above 110 psig, except as specified in 3.4.B.2. The automatic pressure relief function of these valves (but not the OYSTER CREEK 3.4-3 Amendment No.: 75 i

.. . cutomatic d:pr33:urinction function) m2y be inoper blo or bypasced during the system. hydrostatic pressure test required -l by ASME Code Section XI, IS-500 at'or near the end of each ten year inspection interval.

2. If at any time.there are only four operable electromatic relief valves, the reactor may remain in operation for a period not to

-exceed 3 days provided the motor operated isolation and condensate makeup valves in both isolation condensers are demonstrated daily to be operable.

3. If Specifications 3.4.B.1 and 3.4.B.2 are not met; reactor pressure shall be reduced to 110 psig or less, within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />.

4. The time delay set point for initiation after coincidence of low-low-low reactor water level and high drywell pressure shall be set not to exceed two minutes.

C. Containment Sorav System and Emeroency Service Water Svetem l 1. The containment spray system and the emergency service water systera shall be operable at all times with irradiated fuel in the reactor vessel, except as specified in Specifications 3.4.c.3, 3.4.c.4, 3.4.c.6 and 3.4,c.8.

2. Theabsorgtionchamberwatervolumeshallnotbelessthan 82,000 ft in order for the containment spray and emergency service water system to be considered operable.

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If one' emergency service water. system 1oop becomes inoperable, its associated containment spray system loop shall be considered inoperable. If one containment spray system loop

-and/or its associated emergency service water system loop becomes inoperable during the run mode, the reactor may remain in operation for a period not to exceed 7 days provided the remaining containment spray. system loop and its associated emergency service water system-loop each have no inope) ble l components and are demonstrated daily to be operable.

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4. If a pump in the containment spray system or emergency service L water system becomes inoperable, the reactor may remain in .

operation for a period not to exceed 15 days provided the other similar pump is demonstrated daily to be operable. A maximum of two. pumps may be inoperable provided the two pumps are not in the same loop. If more than two pumps become inoperable, the limits of Specification 3.4.C.3 shall apply.

5. During the period when one. diesel is inoperable, the

!. containment spray loop and emergency service water system loop l connected to the operable diesel shall have no inoperable L components.

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6. If primary containment integrity is not required (see l

Specification 3.5.A), the containment spray system may be made jl inoperable. I L

l' OYSTER CREEK 3.4-4 Amendment No.: 75

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7. If Specification 3 3.4.C.3, 3.4.C.4, 3.4.C.5 or 3.4.C.6 cro not :

met, the reactor shall be placed in cold shutdown condition.

If the containment spray system or the emergency service water system becomes inoperable, the reactor shall be placed in.the cold shutdown condition and no work shall be performed on the -

reactor or its connected systems which could result in lowering' the reactor water level to less than 4'8" above the top of the-active fuel.

8. The containment spray system may be made inoperable during the integrated primary containment leakage rate test required by Specification 4.5, provided that the reactor is maintained in l' the cold shutdown condition and that no work is performed on-the reactor or its connected systems which could result in lowering the reactor level to less than 4'8" above the top of the active fuel.

D. Control Rod Drive Hydraulic System

1. The control rod drive (CRD) hydraulic system shall be operable when the reactor water temperature is above 212 F except as ,

specified in 3.4.D.2 and 3.4.D.3 below. I

2. If one CRD hydraulic pump becomes inoperable when the reactor l water temperature is above 212*F, the reactor may remain in operation for a period not to exceed 7 days provided the second CRD hydraulic pump is operating and is checked at least once every 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br />.. If this condition cannot be met, the reactor water temperature shall be reduced to less than 212'F.

3. During reactor vessel pressure testing, at least one CRD= pump shall be operable.

E. Core Sorav and Contalnment Sorav Pumo Comoartmente Doors

-- t The core spray and containment spray pump compartments doors shall be-closed at.all times except during passage in order to consider the

• l core spray system and the containment spray system operable.

le F. Fire Protection System

1. The' fire protection system shall be operable at all times with fuel in the reactor vessel except as specified in Specification 3.4.F.2.

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2. If the fire protection system becomes inoperable during the run mode,.tke reactor may remain in operation provided.both core spray system loops are operable with no inoperable components.

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This specification assures operability of the emergency core cooling l l system to provide adequate core cooling. The Oyster Creek ECCS has two

! core spray loops; each containing a core spray sparger, two main pumps and two booster pumps. Specification 3.4.A.1 insures the availability of 1- l l OYSTER CREEK 3.4-5 Amendment No.: 75

.: c:re cooling.to me;t th3 ECCS cec:ptcnco critcric in 10CFR50.46' utilizing

. -theMApLHCRl{mitsprovidedinSection3.10. These limits are from ca19ulationsI I that include models and procedures which are specified in 10CFR50 Appendix K. A core spray flow of at least 3400 gpm (1 main and 1 b9o ter pump) from 1 loop plus 2200 gpm (1 main pump) from tho'other loop e- . vessel pressure of>110 peig is used in the calculation.. Core spray loop 2 would be required to deliver 3(40 gpm if loop 2 is relied upon as the two. pump contributor and 2360 gpm if loop 2 is the single pump contributor, since loop 2 has flow losses through cracks in the ccre spray sparger.

Specification 3.4.A.3 allows continued operation with one core spray loop inoperable for a limited period of time. . An evaluation of data presented in Reference 5 shows that flow from a single core spray sparger, main and booster pumps delivering 3400 gpm (3640 gpm for loop 2) at a vessel pressure of 110 peig, will meet 10 CFR 50.46 criteria with a 10% reduction in MAPLHGR Limits specified in Section 3.10. At 90% of the APLHGR, each s core spray system is capable of supplying the required minimum bundle flow rate to ensure core cooling (References 6 and 7). Two hours is allowed for a reduction in the APLHGR limit which is consistent with two hours provided by Specification 3.lO.A.3 to return an exceeded APLHGR to within the prescribed limit.

Under the operational constraints of Specification 3.4.A.3 the operable core spray loop meets all Appendix K requirements except for the case of a core spray line break inside the drywell in the operable loop. As a result, reactor operation is permitted for s period not to exceed seven days. The allowed time out of service for the redundant core spray loop is justified based on the low probability of the event, the direct operator  !

indication of a Core Spray System pipe break, and emergency procedures -!

which provide for additional cooling water through the fire system.

The probability of a pipe break between the reactor vessel and the core spray check valve in the operable core spray loop (approx. 28 feet of 6 inch pipe) compared to the total pipe in the reactor coolant pressure boundary is very small. The probability of a core spray line break in conjunction with the other core spray loop out of service, which in itself is a low probability, is so small that it does not constitute an

, unacceptable risk. In the extremely unlikely event that this LOCA scenario were to occur, the operators are provided with a specific visual and-audiblo alarm alerting them of a " Core Spray System I (II) Pipe Break" (one for each core spray loop). These alarms are initiated by differential pressure detectors on each core enray loop. In such a case the core spray line break would occur above the top of the active fuel allowing the core-to be re-flooded from the fire protection system through the intact core spray loop.

In addition, a small break LOCA in the operable core spray loop prior to a larger break will be detected by the drywell unidentified leakage system (drywell sump) even before it is detected by the core spray alarm system.

This will provide the operators with additional time to respond.

Therefore, the out-of-service time for one of the two core spray loops, as evaluated as per the guidelines in Reference 8, has been conservatively selected to be 7 days.

OYSTER CREEK 3.4-6 Amendment No.: 75

. Specification 3.4.A.4 allows continued operation with one component ~

inoperable for a limited period of time. Each core spray loop contains redundant active components based upon Reference 1 or 5, as appropriate.

Therefore, with the loss of one of these components, the system as a whole J (both loops) can tolerate an additional single failure of one of its active components and still perform the intended function and meet 10CFR50.46 criteria. If a redundant active component fails, a fifteen day period is

-allowed for repairs, based on 1 out of 4 components being required. I 3.4.A.4.b insures that the 1 out of 4 requirement is maintained. l Ls '

l l Specification 3.4.A.5 ensures that if one diesel is out of service for j repair, the core spray components fed by the other diesel must be operable. Since.each diesel will provide power to components for both core spray loops, the required flow specified in the bases for Specification 3.1.A.1 will be met.

When the reactor is in the shutdown or refueling mode and the reactor coolsnt system is less than 212'F and vented and no work is being performed that could result in lowering the water level to less than 4'8" above the core, the likelihood of a leak or rupture leading to uncovering of the core i,

is very low. The only source of energy that must be removed is decay heat i L and one day after shutdown this heat generation rate is conservatively L calculated to be not more than 0.6% of rated power. Sufficient core spray f35, to cool the core can be supplied by one core spray pump or one of the

l. two fire protection system pumps under these conditions. When it is l l

necessary to perform repairs on the core spray system components, power i supplies or. water sources, Specification 3.4.A.7 permits reduced cooling L system capability to that which could provide sufficient core spray flow from two independent sources. Manual initiation of these systems is  ;

adequate since it can be easily accomplished within 15 minutes during which time the temperature rise in the reactor will not reach 2200'F.

i l In order to allow for :ertain primary system maintenance, which will L include control rod drive repair, LPRM removal / installation, reactor leak test, etc., (all performed according to approved procedure), Specification-3.4.A.8 requires the availability of an additional core spray pump in an independent loop, while this maintenance is being performed the likelihood  ;

i of the core being uncovered is still considered to be very low, however, the requirement of a second core spray pump capable of full rated flow and the 72 hour8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> operability demonstration of both core spray pumps is specified.

I Specification 3.4.A.10 allows the core spray system to be inoperable in the cold shutdown or refuel modes if the reactor cavity is flooded and the spent fuel pool gates are removed and a source of water supply to the reactor vessel is available. Water would then be available to keep the  ;

core flooded.

The relief valves of the automatic depressurization system enable the core spray system to provide protection against the small break in the event the feedwater system is not active.

OYSTER CREEK 3.4-7 Amendment No.: 75

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, The containment spray system is provided to remove heat energy from the.

containment in the event of a loss-of-coolant accident. The flow from one pump in either loop is more than ample to provide the required heat removal capability (2). The emerger:y service water system provides cooling to the containment spray heat exchangers and, therefore, is required to provide ,

the ultimate heat sink for the energy release in the event of a: j loos-of-coolant accident. The emergency service water pumping requirements are those which correspond to containment cooling heat exchanger' performance implicit in the containment cooling description. Since the I loss-of-coolant accident while in the cold shutdown condition would not require containment spral, the system may be deactivated to permit integrated leak rate testing of the primary containment while the reactor is in the cold shutdown condition.

s Thecontrolroddrivehydraulicsystemcanprovidehighpressurecoolant injection capability. For break sizes up to 0.002 ft , a single control rod drive pump with a flow of 110 gpm is adequate for maintaining the water level nearly five feet above the core, thus alleviating the necessity for auto-relief actuation (3).

The core spray main pump compartments and containment spray pump compartments were provided with water-tight doore(4). Specification 3.4.E ensures that the doors are in place to perform their intended function.-

Similarly, since a loss-of-coolant accident when primary containment integrity is not being maintained would not result in pressure build-up in the drywell or torus, the system may be made inoperable under these conditions. This prevents possible personnel injury associated with.

contact with chromated torus water.

References

1. NEDC-31462P, " Oyster Creek Nuclear Generating Station SAFER /CORECOOL/GEbTR-LOCA Loss-of-Coolant Accident Analysis," August 1987.

2. Licensing Application, Amendment 32, Question 3

3. Licensing Application, Amendment 18, Question 1

4. Licensing Application, Amendment 18, Question 4

5. GPUN Topical Report 053, " Thermal Limits with One Core Spray Sparger" December 1988.

NEDE-30010A, " Performance Evaluation of the Oyster Creek Core Spray Sparger", January 1984.

Letter and enclosed Safety Evaluation, Walter A. Paulson (NRC) to P. B.

Fiedler (GPUN), July 20, 1984.

. APED-5736, " Guidelines for Determining Safe Test Intervals and Repair Times for Engineered Safeguards", April 1969.

OYSTER CREEK 3.4-8 Amendment No.: 75