Text

Application for Amend to License NPF-43,changing TS to Provide Revised Action Requirements for Emergency Equipment Cooling Water & Emergency Equipment Svc Water Sys,Per Generic Ltr 91-18
	ML20086J740
Person / Time
Site:	Fermi
Issue date:	12/05/1991
From:	Orser W; DETROIT EDISON CO.
To:	; NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
Shared Package
ML20086J745	List: ML20086J746; NRC-91-0144, Application for Amend to License NPF-43,changing TS to Provide Revised Action Requirements for Emergency Equipment Cooling Water & Emergency Equipment Svc Water Sys,Per Generic Ltr 91-18;
References
	CON-NRC-91-0144, CON-NRC-91-144 GL-91-18, NUDOCS 9112120070
	Download: ML20086J740 (12)
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Decembe r 5,1991 .D NRC-91-0144 U. S. Huelcar Regulat ory Ccanaission Attnt Doctanent Conttol Der.k Washingt on. D. C. 20555

References:

1) Feral 2 NRC Docket No. 50-341 NRC License No. NPF-43

2) Det roit Edison let ter t o NRC. NRC-87-0244, dated Match 10, 1988

3) Detroit Edison let ter to NRC, NkC-89-0042, dated May 31, 1989

4) Dettoit Edison letter t o NRC NRC-89-0242, dated January 3,1990

5) Dottoit Edison letter to NRC. NRC-91-0080 dat ed July 2,1991

6) Detroit Edinon let ter to NRC, NRC-91-0156, dated November 27, 1991

7) Amendment 51 to Fe wi 2 Operating License NPF-43, dated February 20. 1990

8) Generic Letter 91-18 "Inf ormation to Licensees Regarding Two NRC Inspection Manual Sections on Resolution of Degraded and Nonconf orming Conditions and on Operability," dated November 7,1991

Subject:

Proposed Technical Specification Change (License ,

Amendment) - Emotgency Equipment Cooling Water and Emergncy Equipment Servi _ce Water Pursuant 'to 100FR50.90. Detroit Edison Company hereby proposes to amend Operating License NPF-43 for tho-Fermi 2 plant by incorporating the enclosed changes into the Plant Technical Specifications (TS).

The proposed change provides revised action requirements for the Emergency Equipment Cooling Water (EECW) and the Emergency Equipmt4nt Service Water ' (EESW) syst ems.- This submittal also proposes changes to the TS action requitements f or systems which receive EECW cooling where the supported system allowed outage time (A0T) is tnore g restrictive than the EECW AOT. These action requirements vote the o d)\

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tis!1RC December S.1991 1;RC-91-0144 Page 2 subject of previous ptopocals (Feferencer 2. 3 and 4). In Ecferenceo 5 and 6. Detroit Edison commit tal to provide a TS change proposal for EECW. Tbie proposal satisfies these cmmitment s.

Detroit Edison has evaluated the proposed Technical Specifications against the etiteria of 10CFR$0.92 and determined that no significant har.arda consideration is involved. The Femi 2 Onnit e Reviev Organir.ation has approved and the lluclear Safety Review Group has reviewed the proposed Technical Specificatiour and concurs with the enclored deter minat ions. In accordance with 10CFP50.91. Detr oit Edison han provided a copy of this letter to the State of Michigan.

If you have any questions, please contact Mr. Glen D. Ohlemacher at (313) 586-4275.

Since rel y.

7 Encionate cc C. E. Carpenter. Jr.

A. li. Davis R. W. DeFayette S. Stasek Supetvisor. Electric Operators. Michigan Public Service Cmmionion - J. R. Padget t

I USNRC NRC-91-0144 Tate 3 l

I. WILLI AM S. ORSER. do hereby af firm that the f otogoing statments are based on (acts and circumstaneen which are true and aceutate to the beat of ny knowledge and belief.

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f/ ( ( /$Y-WILLI AM S. ORSP.R

' Il'lk' Senior Vice President On this I day of _I #fffd/ ( _. 1991, b fore me personally appeared William S. Orcer, being if rut duly sworn and says that he executed the foregol.ng as his f ree act and deed.

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Enclosure to NRC-91-0144 Page 1 INTRODUCTION The proposed TS change is being made to reconcilf, the TS required actions for the Emergency Equipment Cooling Water (EECW) and Emergency Equipment Service Water (CESW) systems and the TS required actions for certain systems which recolve EFCW/EESW cooling. These systems are the Emergency Core Cooling Systems (ECCS), the A.C. electrical distribution, and the battery chargers. In each system, the TS required action for the inoperability of the EECW/EESW supported equipment is more limiting than the required action for an EECW/EESW subsystem inoperability.

The need to reconcile these TS actions came from the issuance of Generic Letter (CL) 91-18, (Reference-8) which distributed an NRC Inspection Manual, Part 9900 Section on the topic of operability.

This section indicated that when the TS required action for a support system is less restrictive-than a TS required action for a supported system then the nost restrictive action should be followed until the inconsistencies are resolved. The section also indicates that an amendment to the TS may be necessary.

Previous to the issuance of C1 91-18, Detroit Edison had identified this inconsistency between the EECW/EESW action requirements and the action requirements of the supported systems. While resolving the inconsistency with the NRC, addillonal actions, such as checks of opposite train equipment to assure that complete loss of a safety _ ,

function did not occur, were implemented, liowever, the most restrictive actions from tha supported system TS requirements were not taken since these actions did not appear warranted by the safety significance of the situallon nor intended by the TS and original licensing basis. Discussions with NRC representatives since the issuance of GL 91-18 made it clear that the most restrictive actions should be taken immediately upon loss of EECW cooling and that a license amendment would be required to resolve tnis attuation.

Detroit Edison does not believe that this was the intent of the original EECW/EESW action requirements and is in support of the ,

ongoing dialog between industry owners' groups and the NRC toircach a generio position on this issue. Prompt resolution of the EECW/EESW action requirements, however, is needed to support continued plant operation, necessary' surveillance testing and preventive maintenance on these systems.

Detroit Edison is electing to resolve this issue, at least for the near future, by proposing a TS change where the systems supported by EECW would be immediately declared inoperable and the associated TS actions are directed to be taken. Certain of these supported systems' TS requirements are also proposed to be modified to specifically address the degradation caused by the loss of EECW cooling.

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I Enclosure to NitC-91-0144 Pago 2 1 EVM UATION The Emergency Equipment Cooling Water (EECW) system provides cooling to equipment essent,tal to reactor shutdown wnenever the normal cooling to this equipnent is unavailablo. The Emergency Equipment Servlee Water (EESW) system provides cooling to the 1:CCW system and is in turn cooled by the Ultimato llcal Sink. The sole function of the EESW system is to cool the EECW system.

The EECW and EESW systems each consist of two subsystemn. The subsystems are independent, and divisionalized. The essential safety-related equipment, supported by EECW la an follows:

o Itesidual llent itemoval (Illilt) Pumps o Coro Spray (CS) Pumps o Non-interruptiblo Control Air Compressors o Thermal Recombiner System o Electrical Switchgear '

o Henetor Coro isolation Cooling (11C10) o liigh Pressuro Coolant, injection (llPCI) o Standby Cas Treatment Syst.em o- Control Room Emergency Filtration System o Essent,lal Battery Chargers Heat. removal from this equipment. la normally via the non-safety related Reactor Building Closed Cooling Water (ItBCCW) system. The t,wo EECW nystem subsystems are in ofrect two branches in the distritsution of RBCCW system cooling water. In the event, of an EECW initiat,lon signal (loss of IWCCW supply pressura, loss of power to the HBCCW pumps or high drywell pressure) the !!DCCW system valves are automat,1cally repositioned to form the two independent, EECW subsystems. The RDCCW pumps and heat, exchangers are isolated from the EECW subsystems, and the EECW pumps roccivo a start signal. A simplified sketch is attached. The EECW/EESW system design was reviewed and accepted by the NHC in tho Fermi 2 Safety Evaluation Report (NUREG-0798), Section 9.2.1.

The current TS requirements for EECW (TS 3 7.1.2) and EESW (TS 3 7.13) provide for a 72 hour8.333333e-4 days 0.02 hours 1.190476e-4 weeks 2.7396e-5 months allowed outage timo ( AoT) for loss or one subsystem. After the 72 hour8.333333e-4 days 0.02 hours 1.190476e-4 weeks 2.7396e-5 months A0T expires, a plant shutdown is required, the associated safety-relat,ed equipment is t,o be declared inoperable and the applicable action requirements for the supported equipment, followed.

This TS action creates severni problems. First, the use of the 72 hour8.333333e-4 days 0.02 hours 1.190476e-4 weeks 2.7396e-5 months ACT is not appropriato in situaiaons where an opposite train component, which N "ellant, on the remaining operable EECW subsystem, is also inoperable. In this case, the safety function may be lost, and a more restrictive action requirement should be applied. The proposed TM addresses this issue by requiring a verification of opposito train 1

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Enclosure to llRC-91-0144 Page 3 equipment within two hours, which if not completed, requires a prompt plant shutdown.

This is consistent with the guiding principle, expressed in GL 91-18.

that the capability to perform a safety function must not be lost due to inoperabilities in nore than one train. Requiring a plant shutdown if a safety function is lost is consistent with the TS actions for these functions. An exception la made for the alternative shutdown system where the TS provides an appropriate action statement for less of both trains of the EECW supportej drywell cooling units.

The second problem is that the operability status of plant equipment should reflect the physical state of the equipnent. The current TS provision could lead to the conclusion that it is acceptable to consider inoperable equipment operable during a 72 hour8.333333e-4 days 0.02 hours 1.190476e-4 weeks 2.7396e-5 months A0T. This is inconsistent with both the operability definition and ino actual status of the equipment. Therefore, the proposed "5 requires that associated safety-related equipment nade inoperable by loss of EECW cooling be declared inoperable at the time cooling is lost.

The proposed TS then directs that the action requirements for the supported systems be taken. This is the clearest way of assuring that the necessary action requirements (including any remedial actions) are taken. Since the supported system TS requirements were not written to take into account a loss of EECW cooling, certain supported system TS must be changed. These systems are the ECCS, A.C. electrical distribution and the battery chargers.

The Fermi 2 Emerf,ency Core Cooling System (ECCS) network consists of a standard BWR-4 design consisting of a Low Pressure Coolant Injection <

(LPCI) system, a Core Spray System (CSS), a High Pressure Coolant injection (HPCI) system and an Automatic Depressurization System (ADS). The I.PCI systems and CSS consist of two redundaac subsystems.

The HPCI system and ADS provide redundant function *.

The TS actions for the ECCS allow one of the six systems or subsystems, detailed above, to be inoperable for time periods of seven (7) through fourteen (14) days. The time periods reflect the defense in depth of the ECCS network. Circumstances where more than one system / subsystem would be simultaneously inoperable were considered to be unlikely when the TS were drafted. Therefore, actions with shorter A0Ts were not included in the original TS.

Loss of the Division II EECW subsystem results in the inoperability of the Division II LPCI and CSS subsystems and the HPCI system. Loss of the Division I EECW system results in inoperability of the Division 1 LPCI and CSS subsystems. ADS is not affected by a loss of EECW.

The current ECCS TS actions (TS 3 5.1) do not cover the resulting ECCS inoperabilities for the situation when an EECW subsystem is

'o ., i Enclosure to NRC 91-0144 j Page 4 j i

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inoperable. TS 3.5 1 does not contain an action stat.cment that addresses the multiple subsystem inoperabilities which result. l Therefore, entry into TS 3 0 3 and an immediato plant, shutdown is i j

required. Tha proposed TS changes overcomo this problem by including a provision which addresses loss of an EECW subsystem within the TS j E 3 5.1. actions.

The exJsting evaluation in the UFSAR of a failure of a divisional battery provides a conservative evaluation of the impact on the ECCS of a loss of that division of EECW. The battery failure causes the control power to motor-operated valves for the ECCS within the affected division to be lost not allowing the ECCS in that division to operate. This bounds the EECW case where the ECCS in a division would operate but be subject to subsequent failuro duo to loss of cooling.

The ECCS performance evaluation (UFSAR Section 6.3 3) or the divisional battery failure shows that all ECCS acceptance critoria of 10CFR50.46 are met. The results are displayed in UFSAR Figure 6 3-17 These evaluations have been reviewed and accepted by the NRC in the Fermi 2 SER, Section 6.3 4.

The proposed changes to TS 3 6.1 provido directions which result, in the 72 hour8.333333e-4 days 0.02 hours 1.190476e-4 weeks 2.7396e-5 months A0T of the EECW TS being limiting when loss of EECW cooling requires entry into 3 5.1. The cross-train checks, discussed above, assure that sufficient, equipment remains operable to meet the ECCS functional requirements.

The EECW system also supports the A.C. electrical distribution equipment and the bat,tery chargers. The current TS A0Ts for loss of one division of these syst. ems are 8 hours9.259259e-5 days 0.00222 hours 1.322751e-5 weeks 3.044e-6 months and 2 hours2.314815e-5 days 5.555556e-4 hours 3.306878e-6 weeks 7.61e-7 months , respectively.

!!owever, these A0Ts do not reflect the capability of this equipment under accident conditions without EECW cooling.

The EECW supports the A.C. electrical distribution system by cooling the rooms in which the equipment is located. These rooms are

' maintained by non-safety air conditioning systems at less than ,

86 0F, This temperature is chosen to prevent accelerated aging of electronic' components in the room. The room equipment. Will function l

properly with temperatures up to'122 F.

l An evaluation of room temperature versus time has shown that post-accident without EECW cooling the room temperature increases from 86U F to 1220 F in 8 hours9.259259e-5 days 0.00222 hours 1.322751e-5 weeks 3.044e-6 months and 24 minutes for Division Il and 10 i

hours and 2 minutes for Division I. The non-safety air conditioning is assumed to fail at, the time of the accident.

The battery charEers are similarly supported by EECW; however, the room temperature increases much less rapidly than for the A.C.

electrical distribution. Since the battery chargers require an A.C.

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Enclosure to NRC-91-0144 Page 5 power supply, the battery chargers' capability wl.thout EECW is limited by-the A.C. electrical distribution capability.

The propoLed TS allows the action requirements for this equipment to be delayed La reflect this post-accident. capabilit,y. Since the systems retain their full capability for a period of t,ime following an accident it wtuld appear to be appropriate to 6110w a time period of at least.this long for a delay in taking these action requirements.

Therefore, a delay of 8 hours9.259259e-5 days 0.00222 hours 1.322751e-5 weeks 3.044e-6 months for Division 11.and 10 hours1.157407e-4 days 0.00278 hours 1.653439e-5 weeks 3.805e-6 months for Division I is proposed for these actions. Thhse delay times are based upon conservative calculations which are curmntly being refined.

Should the revised cal.uulations support appreciably longer delays, Detroit Edison may supplement this proposal to reflect the longer delays, t In Operational Condition 4 and 5, there is no need to consider cont.inued plant operation. The incent is to take the action for any equipment which is rendered inoperable by the loss of EECW cooling.

Whether or not a piece of equipment should be considered inoperable depends upon the impact of the loss of ECCW on the equipment's ability to perform its intended function. In Operational Conditions 4 or 5, the need for-EEGW cooling may depend upon the design basis scenarios which can credibly. occur in these conditions. Thus, there could be no actual impact on the equipment's ability to perform its intended

. function with a loss of EECW cooling. For example, some EECW cooled room coolers may not be netded under accident conditions when the reactor is at low temperatures. The equipment in these rooms thus would still be-able to fully perform its intended functions and would not naed to be declared fi,uperable.

The EECW system is designed ,,a provide cooling to-equipment essential to achieving and maintaining safe shutdown conditions under postulated accident conditions. The worst-case conditions are generally those following an accident originating 'derring power operat. tan. There are a number of specific circumstances possible in Operational Conditions 4 and-5 for which the worst-case conditions are substantially less severe tnan those possible at power. Engineering evaluation of each l: specif4?. circumstance-may result in a determination that the equipment l .of cc m rn can be considered operable. The proposed action b. of TS

- 3 7.1.2 reflects the intended action without mixing the Operational Conditions 4 and 5 requirements with the more complex Operational' Condition 1, 2 and 3 requirements.

h In License Amendment'51 (Reference 7) the Ultimate Heat Sink TS (3 7.1.5) was changed to refer only to equipment or systems which are directly supported by the Ultimate Heat Sink. This proposal continues

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-that philosophy for EESW in that the proposed EESW TS requires the f,ECW action to be taken. EESW cools only the EECW system. Thus, restructuring of the action alone does not in itself change the requirements from the current Technical Specification requirements.

Enclosure to NRC-91-0144 Fege 6 The proposed restruct ring still requires the same actions for an EESW inoperability as for an EECW Inoperability but eliminates duplication of the EECW requirements. The proposed structure also supports a more systematic evaluation of the impact of the inoperability of this system. In this way, the proposal provides a clear and simple format for these requirements while ensuring the proper actions for the supported systems are taken.

In tummary, these TS changes act to eliminate any potential conflict between the explicit TS actions for EECW nd the application of tne operability definition to the suppcrte ett m TS.

When the most restrictive. V' Os are % , sied, as ceacribed in GL 91-18, EECW/EESW systen outages are essentially prohibited since such an outage would cause entry into the TS 3.0 3 provisions. System outages for these systems are periodically necessary to allow for surveillance testing activities and minor preventir maintenance to be performed. Such activities act to enhance these systems' reliability and availability and thus act to benefit safety. The proposed chandes are consistent with the intent of CL 91-18 which indicates that it "is not the intent of surveillance or other similar program requirements to cause unwarranted plant shutdowns..."

Also, when the most aestrictive action requirements of the current TS's are immediately 0.pplied they give no allowance for tinor corrective maintemnce on the EECW/EESW systems. These corrective maintenance items currently would require a plant shutdown where an adequate safety basis exists for ACT's sufficient to accommodate them. These unwarranted plant shutdowns would place unnecessary cycles on plant equipment. These plant evolutions also craate a greater probability of an abnormal plant transient being initiated due to the increased activity during the evolutions. Eliminating these plant shutdowns is a safety benefit.

SIGNIFICANT llAZARCS CONSIDERATION In accordance with 10CFR50.92, Detroit Edison has made a determination that the proposed amendment involves no significant hazards considerations. To make this determination, Detroit Edison must establish th".t operation in accordance with the p-oposed amendment would not: 1) involve a significant increase in the probability or consequences of an accident previously evaluated, or 2) create the possibility of a new or different kind of accident from any accident pre.iously evaluated, or 3) involve a significant reduction in a margin of safety.

The proposed change provides revised action requirements for the Emergency Equipment Cooling Water (EECW) system, Emergency Equipment Service Water (EESW) system and certain systems which receive EECW cooling. The change requires additional actions to be taken for an

Enclosure to NRC-91-0144 Page 7 inoperable EECW subsystem to ensure a loss of safety function has not occurred and directs that the action requirements for systems made inoperable by the loss of EECW cooling be immediately taken. Certain of the supported system action requirements are changed to reflect the impact er loss of EECW cooling on the supported equipment. The proposed change does not:

1) Involve a significant increase in the probability or consequences of an accident previously evaluated. The proposed change does not create any new initiating mechanisms or affect any postulated initiating mechanisms for evaluated accidents. The proposed change provides action requirements that. address the impact of EECW cooling on certain systems which receive EECW cooling.

These action requirements assure that sufficient equipment remains available to safely shutdown the plant as currently evaluated in the UFSAR. The UFSAR evaluation of ECCS performance shows that equipment supported by a single EECW subsystem can meet the acceptance criteria of 10CFR50.46. Therefore, the proposed change does not represent a stEnificant irrrease in the probability or consequences of a previously evaluated accident.

2) Create the possibility of a new or different kind of accident from any accident previously evaluated. The proposed change does not result in any modifications to the plant design or manner of system operation and no safety-related equipment or function will be altered. As stated in 1) above, sufficient equipment will be maintained and will be available to initiate safe shutdown of the plant. The requested changes do not create any new accident mode.

3) Involve a significant reduction in a margin of safety. As stated in 1) above, the proposed action requirements assure that sufficient equipment is available to safely shutdown the plant.

The proposed change nay also promote safe plant operation by giving a reasonable out-of-service time for corrective and preventive maintenance and testing activities on the EECW and EESW systems without requiring unnecessary reactor shutdowns.

Based on the above, Detroit Edison has determined that the proposed amendment does not involve a significant hazards consideration.

ENVIRONMENTAL IMPACT Detroit Edison has reviewed the proposed Technical Specification changes against the criteria of 10CFR51.22 for environmental considerations. The proposed change does not involve a significant hazards consideration, nor significantly change the types or significantly increase the amounts of effluents that may be released offsite, nor significantly increase individual or cumulative occupational r adiation exposures. Based on the foregoing, Detroit

Enclosure to NRC-91-0144 ,

Page 8 Edison colicludes that the proposed Technical Specifications do meet the criteria given in 10CFR51.22(c)(9) for a categorical exclusion from the requirements for an Environmental Impact Statement.

CONCLUSION Based on the evaluation above: 1) there is reasonable assurance that

- the health and safety of the public will not be endangered by operation in the proposed manner, and 2) such activities will be conducted in compliance with the Commission's regulations and proposed amendments will not be inimical to the common defense and security or to the health and safety of the public.

In order to provide time for the revision of site docutients, it is requested that the proposed change be issued with a seven day implementation period, l

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NRC-91-0144, Application for Amend to License NPF-43,changing TS to Provide Revised Action Requirements for Emergency Equipment Cooling Water & Emergency Equipment Svc Water Sys,Per Generic Ltr 91-18

Text

References:

Subject:

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