ML20196G367

Proposed Tech Specs Increasing AOT for Crac from 30 Days to 60 Days on One Time Basis for Each Train to Facilitate on- Line Implementation of Design Enhancements During Current Operating Cycle

ML20196G367
Person / Time
Site:	Seabrook
Issue date:	06/23/1999
From:	NORTH ATLANTIC ENERGY SERVICE CORP. (NAESCO)
To:
Shared Package
ML20196G342	List: ML20196G338 ML20196G353 ML20196G367
References
NUDOCS 9907010136
Download: ML20196G367 (17)

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r Section II Markup Of The Proposed Change The attached markup reflects the currently issued revision of the Technical Specifications listed below.

Pending Technical Specifications or Technical Specification changes issued subsequent to this submittal are not reflected in the enclosed markup The following Technical Specification is included in the attached markup:

Technical Specification Title Page(s) 3/4.7.6 Control Room Subsystems-Air Conditioning 3/4 7-18a i.

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l 9907010136 990623 Page 7 PDR ADOCK 05000443 P PDR i

PLANT SYSTEMS (1 J 3/4.7 6 CONTROL ROOM SUBSYSTEMS k AIR CONDITIONING $

4 LIMITING CONDITION FOR OPERATION 3.7.6.2 Two independent Control Room Air Conditioning Subsystems shall be ,

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OPERABLE.

APPLICABILITY: All MODES k ACIl0N. i l MODES 1. 2, 3 and 4:

With one Control Room Air Conditioning Subsys em noperable, restore the inoperable system to OPERABLE status within 3 ' ys or be in at least HOT ,

STANDBY within the next 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> and in COLD SHUTDOWN within the following 30 ,

i l hours. '

MODES 5 and 6:

a. With one Control Room Air Conditioning Subsystem 1no)erabl . l j 1 restore the inoperable system to OPERABLE status wit,in 3 ys or '

initiate and maintain operation of the remaining OPERABLE Control Room Air Conditioning Subsystem or imediately suspend all o>erations involving CORE ALTERATIONS or positive reactivity c7anges. I j

b. With both Control Room Air Conditioning Subsystems inoperable, or

!i' with the OPERABLE Control Room Air Conditioning Subsystem unable to maintain temperature below the limiting equipment qualification '

temperature in the control room area, suspend all o)erations l involving CORE ALTERATIONS or positive reactivity c1anges.  ; j i

SURVEILLANCE REOUIREMENTS {

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I 4.7.6.2 Each Control Room Air Conditioning Subsystem shall be demonstrated l OPERABLE at least once per 92' days by verifying the ability to maintain i temperature in the control room area below the limiting C 9t qualification ll temperature for 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />. _

- Y fw cycle 7, the allouuWe cahy eme may be eckm'ed Mo days, on a one-time basis'i foreach train, 4 Impkmerit mxfincafias Mhe 8 A f0W QIf 0DnO't$0Hj Suhyfems. Qg ,3(ogrij) cps Ch yc}NCafto/lS i 0'0$ OMi C nS h Mc M gireg,g V orc notag;horliny stjbspr>g/

. i SEABROOK - UNIT 1 3/4 7-1Ba Amendment No.56

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SECTION III Retype Of The Proposed Change The attached retype reflects the currently issued version of the Technical Specifications. Pending Technical Specification changes or Technical Specification changes issued subsequent to this submittal -

are not reflected in the enclosed retype. The enclosed retype should be checked for continuity with Technical Specifications prior to issuance.

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F PLANT SYSTEMS

~ 3/4.'7.6 CONTROL ROOM SUBSYSTEMS 1

AIR CONDITIONING LIMITING CONDITION FOR OPERATION 3.7.6.2 Two independent Control Room Air Conditioning Subsystems shall be OPERABLE.

APPLICABILITY: All MODES ACTION: .a MODES '1, 2, 3 and 4:

With one Control Room Air Conditioning Subsystem inoperable, restore the inoperable system to OPERABLE status within 30* days or be in at least HOT STANDBY within the next 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> l 1 and in COLD SHUTDOWN within the following 30 hours3.472222e-4 days <br />0.00833 hours <br />4.960317e-5 weeks <br />1.1415e-5 months <br />. '

i MODES 5 and 6:

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a. With one Control Room Air Conditioning Subsystem inoperable, restore the j inoperable system to OPERABLE status within 30* days or initiate and maintain l  :

operation of the remaining OPERABLE Control Room Air Conditioning l Subsystem or immediately suspend all operations involving CORE

! ALTERATIONS or positive reactivity changes.

b. With both Control Room Air Conditioning Subsystems inoperable, or with the OPERABLE Control Room Air Conditioning Subsystem unable to maintain temperature below the limiting equipment qualification temperature in the control room area, suspend all operations involving CORE ALTERATIONS or positive  ;

reactivity changes. i l SURVElLLANCE REQUIREMENTS i I'

4.7.6.2 Each Control Room Air Conditioning Subsystem shall be demonstrated OPERABLE at least once per 92 days by verifying the ability to maintain temperature in the control room area j below the limiting equipment qualification temperature for 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />.  ;

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• For cycle 7, the allowable outage time may be extended to 60 days, on a one-time basis, for I l each train to implement modifications to the Control Room Air Conditioning Subsystems. The j l provisions of Specifications 3.0.4 and 4.0.4 are not applicable during the implementation of modifications to the Air Conditioning Subsystems.

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SEABROOK - UNIT 1 3/4 7-18a Amendment No.46, ,

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i Section IV Determination Of Significant Hazards For The Proposed Change i

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IV. DETERMINATION OF SIGNIFICANT IIAZARDS FOR Tile PROPOSED CIIANGE License Amendment Request (LAR) 99-19 proposes a one-time only change to the action statements of Seabrook Station Technical Specification 3.7.6.2. In modes 1,2,3, and 4, the proposed change would allow North Atlantic 60 days (on a one-time basis) to restore one inoperable Control Room Air Conditioning Subsystem (CRACS) to OPERABLE status or be in at least ilOT STANDBY within the next 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> and in COLD SHUTDOWN within the following 30 hours3.472222e-4 days <br />0.00833 hours <br />4.960317e-5 weeks <br />1.1415e-5 months <br />. In modes 5 and 6, the proposed change would allow North Atlantic 60 days (on a one-time basis) to restore the inoperable system to OPERABLE status or initiate and maintain operation of the remaining OPERABLE Control Room Air Conditioning Subsystem or immediately suspend all operations involving CORE ALTERATIONS or positive reactivity changes. Additionally, an exception to the requirements of TS 3.0.4 and Surveillance Requirement 4.0.4 is proposed as they apply to TS 3.7.6.2 during the implementation of the modification to the CRACS.

In accordance with 10 CFR 50.92, North Atlantic has reviewed the attached proposed change and has concluded that it does not involve a significant hazards consideration (SliC). The basis for the conclusion that the proposed change does not involve a SilC is as follows:

1. The proposed change does not involve a significant increase in the probability or consequences of an accident previously evaluated.

The operational requirements for the Control Room Air Conditioning Subsystems (CRACS) are contained in Technical Specification 3.7.6.2" Control Room Subsystems Air Conditioning." This Limiting Condition for Operation (LCO) requires that two independent Control Room Air Conditioning Subsystems (trains) be operable during all modes of operation. The LCO action statement for operational modes 1, 2, 3 and 4, with one Control Room Air Conditioning Subsystem inoperable, states:" restore the inoperable system to operable status within 30 days or be in at least 110t Standby [ Mode 3] within the next 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> and in Cold Shutdown within the following 30 hours3.472222e-4 days <br />0.00833 hours <br />4.960317e-5 weeks <br />1.1415e-5 months <br />." The LCO action statement for operational modes 5 and 6 with one Control Room Air Conditioning Subsystem inoperable, states:" restore the inoperable system to operable within 30 days or initiate and maintain operation of the remaining OPERABLE Control Room Air Conditioning Subsystem or immediately suspend all operations involving CORE ALTERATIONS or positive reactivity changes."

The proposed change adds the following note:"* For cycle 7, the allowable outage time may be extended to 60 days, on a one-time basis, for each train, to implement modifications to the control room air conditioning subsystems. The provisions of specifications 3.0.4 and 4.0.4 are not applicable during the implementation of modifications to the air conditioning subsystems."

This change is a one-time only change to Technical Specification 3.7.6.2 in order to facilitate the installation of a design change to the CRACS during the present operating cycle. This change will not affect the existing 30 AOT period presently in place in Technical Specification 3.7.6.2 which requires specific actions in the event that the CRACS is determined to be inoperable for any other reason.

The design basis accidents are not affected as a result of the proposed one-time change to the Technical Specifications. The CRACS are support subsystems which can only contribute to the initiation of an accident if the whole function is lost. The plant would be required to shutdown Page 10

n before this occurred. The proposed change does not adversely affect accident initiators or precursors nor alter the design assumptions, conditions, configuration of the facility (other than the CRACS) or the manner in which the plant is operated nor does it adversely affect the response of the plaat to a transient or accident. This one-time change is to be utilized only during the present operating cycle (cycle 7) in order to facilitate the implementation of a design change to modify the existing safety-related refrigerant subsystems (one train at a time) and replace them with safety-related chilled water subsystems. This design change is being implemented to improve the overall reliability of the safety-related subsystems.

The consequences of an extended loss of the operating CRACS and the non-safety related chilled water subsystem, during all modes of operation, would result in a slow gradual rise in control room temperature. The temperature of the control room is normally maintained between 70 to

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72 F at the discretion of the Unit Shift Supervisor utilizing a non-safety-related train of CRACS. l in the event that the control room temperature increased to a temperature greater than 75'F, plant procedures require starting other equipment in the non-safety-related chilled water subsystem or a safety-related train of CRACS to restore control room temperature to its normal operating band.

In the unlikely event that the non-safety-related chilled water subsystems and the operable safety-related train of CRACS fail during the proposed 60 day AOT period, Technical Specification 3.7.6.2 would require that actions be commenced to place the plant in a shutdown condition.

Additionally, alternative actions to reduce control room temperature could also be initiated as identified in a plant procedure. .It has been conservatively determined that safety-related equipment in the control room can be operated continuously up to 90 F in an environment without affecting the capability of the equipment.

The exception to specifications 3.0.4 and 4.0.4 as stated in the proposed one-time change to Technical Specification 3.7.6.2 will not involve an increase in the probability or consequences of an accident. TS 3.0.4 prohibits entry into a mode when the conditions for the LCO are not met and the associated action (s) requires a shutdown if they are not met within a specified time interval. Surveillance Requirement 4.0.4 prohibits entry into a mode unless the associated surveillance requirement (s) has been performed within the stated interval. During the implementation of the modification, when one safety-related train of CRACS is inoperable, it is possible that a plant shutdown could occur due to reasons unrelated to the planned modifications of the CRACS. As stated above, the CRACS are support subsystems which do not contribute to the initiation of any accident previously evaluated. Entry of the plant into an operational mode from a shutdown mode as a result of the proposed modification does not adversely affect accident initiators or precursors nor alter the design assumptions, conditions, configuration of the facility (other than the CRACS) or the manner in which the plant is operated nor does it adversely affect the response of the plant to a transient or accident. The functions of the CRACS to provide a controlled environment inside of the control room complex to ensure the comfort of the plant operators and to ensure adequate climate conditions for the operability of equipment will not be impaired in any way as a result of a plant mode change. The remaining actions identified in TS 3.7.6.2 are unchanged as a result of the proposed change. The risk significance involved with removing a safety-related train of the CRACS during power operation or during refueling l conditions is low based on the short period (60 days per train) and consequences of losing this l function. The CRACS is excluded from modeling in the Seabrook Station Probabilistic Risk Assessment (PRA) due to its extremely low risk significance.

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Therefore, the proposed change does not involve a significant increase in the probability or consequences of an accident previously evaluated.

2. Create the possibility of a new or different kind of accident from any accident previously evaluated.

The proposed change will not create the possibility of a new or different kind of accident from any accident previously evaluated since it is a support system and the loss of function will require a plant shutdown. The proposed change adds the following note which pertains to both affected action statements: "* For cycle 7, the Allowable Outage Time may be extended to 60 days, on a one-time basis, for each train during the implementation of modifications to the control room air conditioning subsystems. The provisions of specifications 3.0.4 and 4.0.4 are not applicable during the implementation of modifications to the air conditioning subsystems." As previously identified, this ( *nge is a one-time only change to Technical Specification 3.7.6.2 in order to facilitate the instanation of a design change to CRACS during the present operating cycle.

The CRACS are support subsystems which do not contribute to the creation of a new or different kind of accident from any previously evaluated nor is it used to mitigate the consequences of a transient or accident. The functions of the CRACS are to provide a controlled environment inside of the control room complex to ensure the comfort of the plant operators and to ensure adequate climate conditions for the operability of equipment. The CRACS consists of two independent safety-related air conditioning trains that provide cooling of recirculated control room air. Due to previous reliability problems with the CRACS, an additional non-safety chilled water subsystem has been installed to provide control room cooling on a continuous basis.

Baseload operation of the non-safety related chilled water subsystem to provide control room .

cooling reduces the operational load on the safety-related refrigerant trains. I implementation of the modification to the CRACS subsystems during the 60 day AOT duration in no way affects the availabiliy of the non-safety-related chilled water subsystem or the operable safety-related train of the CRACS to meet the control room cooling requirements. The proposed modification removes freon from the control room complex and the quantity of chilled water in the closed loop system is too small to become a flood hazard. The consequences of an extended loss of the operating CRACS train and the non-safety related chilled water subsystem

- would result in a slow gradual rise in control room temperature. In the event that control room temperature increased to a temperature greater than 75 F, plant procedures require starting either the non-safety-related chilled water subsystem or a safety-related train of CRACS to restore control room temperature. Additionally, in the unlikely event of a loss of the non-safety related chille6 vater subsystem and the operable safety-related train of the CRACS, Technical Specification 3.7.6.2 would require that actions be taken to place the plant in a shutdown condition.

It has been conservatively determined that safety-related equipment in the control room can be operated continuously in an environment up to 90 F without affecting the capability of the

. equipment. This proposed change will not affect the existing 30 day AOT period presently in place in Technical Specification 3.7.6.2 which requires specific actions in the event that the CRACS is determined to be inoperable for any other reason.

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The exception to specifications 3.0.4 and 4.0.4 as stated in the proposed one-time change to 1

Technical Specification 3.7.6.2 will not involve the creation of an accident of any type. During the implementation of the proposed modification, when one safety-related train of CRACS is l inoperable, it is possible that a plant shutdown could occur due to reasons unrelated to the planned modifications of the CRACS. Entry of the plant into an operational mode from a l shutdown mode as a result of the proposed modification does not adversely affect accident initiators or precursors nor alter the design assumptions, conditions, configuration of the facility or the manner in which the plant is operated nor the manner that it responds to a transient or accident. The functions of the CRACS to provide a controlled environment inside of the control room complex to ensure the comfort of the plant operators and to ensure adequate climate conditions for the operability of equipment will not be impaired in any way as a result of a plant mode change. The remaining actions identified in TS 3.7.6.2 are unchanged as a result of the proposed change.

Therefore, the proposed change will not create the possibility of a new or different kind of accident from any previously evaluated.

3. Involve a significant reduction in a margin of safety.

The proposed one-time change to Technical Specification 3.7.6.2 will not involve a significant reduction in the margin of safety. The functions of the CRACS are to provide a controlled l environment inside of the control room complex to ensure the comfort of the plant operators and to ensure adequate climate conditions for the operability of equipment. The CRACS consists of two independent safety-related air conditioning trains that provide cooling of recirculated control

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room air. Additionally, the Seabrook Station design incorporates the use of a non-safety chilled i water subsystem (which is not within the scope of the Technical Specifications) to provide baseload cooling of the control room on a continuous basis.

Implementation of the modification to the CRACS subsystems during the 60 day AOT duration does not result in a significant reduction in the plant margin of safety. As previously identified, the CRACS is a support subsystem and the existing Technical Specifications will require a plant i shutdown on a loss of function. The risk significance involved with removing a safety-related train of the CRACS is extremely low based on the short period (60 days per train) and the consequences of losing this function. The potential that the non-safety-related chilled water subsystem and the operable safety-related train of CRACS simultaneously fait during the proposed 60 day AOT period of each safety-related train (120 days total) is considered unlikely, in the event that control room temperature increased to a temperature greater than 75 F, plant procedures require starting either the non-safety-related chilled water subsystem or a safety-related train of CRACS to restore control room temperature. Additionally, in the unlikely event of a loss of the non-safety related subsystem and the operable safety-related train of the CRACS, Technical Specification 3.7.6.2 would require that actions be taken to place the plant in a shutdown condition. Alternative actions to reduce control room temperature could also be initiated as identified in a plant procedure. It has been conservatively determined that safety-related equipment in the control room can be operated continuously in an environment up to 90 F without affecting the capability of the equipment.

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a o The exception to specifications 3.0.4 and 4.0.4 as stated in the proposed one-time change to Technical Specification 3.7.6.2 will not reduce the margin of safety. During the implementation of the proposed modification, when one safety-related train of CRACS is inoperable, it is l possible that a plant shutdown could occur due to reasons unrelated to the planned modifications of the CRACS. Entry of the plant into an operational mode from a shutdown mode as a result of l the proposed modification does not adversely affect accident initiators or precursors nor alter the I

design assumptions, conditions, configuration of the facility or the manner in which the plant is operated. The functions of the CRACS to provide a controlled environment inside of the control room complex to ensure the comfort of the plant operators and to ensure adequate climate conditions for the operability of equipment will not be impaired in any way as a result of a plant l mode change. The remaining actions identified in TS 3.7.6.2 are unchanged as a result of the I

proposed change. ,

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Based on the above evaluation, North Atlantic concludes that the proposed change does not constitute a l significant hazard. l l

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l Sectiores V & VI Proposed Schedule for License Amendment Issuance and Effectiveness and EnvironmentalImpact Assessment i

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a a V. PROPOSED SCHEDULE FOR LICENSE AMENDMENT ISSUANCE AND EFFECTIVENESS North Atlantic requests NRC Staff review of License Amendment Request 99-19 and issuance of a

. license amendment by August 31,1999, having immediate effectiveness and implementation required within 30 days.

VI. ENVIRONMENTAL IMPACT ASSESSMENT North Atlantic has reviewed the proposed license amendment against the criteria of 10CFR51.22 for environmental considerations. The proposed change does not involve a significant hazards consideration, nor increase the types and amounts of effluent that may be released off-site, nor significantly increase individual or cumulative occupational radiation exposures. Based on the foregoing, North Atlantic concludes that the proposed change meets the criteria delineated in 10CFR51.22(c)(9) for a categorical exclusion from the requirements for an Environmental Impact Statement.

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I ENCLOSURE 2 TO NYN-99054 l

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l ENCLOSURE 3 TO NYN-99054 i

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t North Atlantic Commitments Contained in NYN-99054 l

Description of Commitment l AR#99009791-01 North Atlantic will develop administrative controls to ensure that j Seabrook Station will not enter the subject action statements of TS 3.7.6.2 to initiate installation of the design changes to CRACS unless the non-safety related chilled water subsystem is functional. This action is only required if LAR 99-19 is approved by the NRC, AR#99009791-02 North Atlantic will develop administrative controls to ensure that Seabrook Station will not exercise the exceptions to TS 3.0.4 and

! Surveillance Requirement (SR) 4.0.4 as they pertain to TS 3.7.6.2 during implementation of the modification to the safety-related CRACS unless the non-safety related chilled water subsystem is l functional. This action is only required if LAR 99-19 is approved by the NRC.

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