ML20210H172

Safety Evaluation Supporting Amends 199 & 182 to Licenses DPR-70 & DPR-75,respectively

ML20210H172
Person / Time
Site:	Salem
Issue date:	07/29/1997
From:	NRC (Affiliation Not Assigned)
To:
Shared Package
ML20210H167	List: ML20210H164 ML20210H172
References
NUDOCS 9708130179
Download: ML20210H172 (6)

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SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION RELATED TO AMENDMENT NOS.199 AND 182 TO FACILITY OPERATING LICENSE HOS. OPR-70 AND DPR-75 PUBLIC SERVICE ELECTRIC & GAS COMPANY PHILADELPHIA ELECTRIC COMPANY DELMARVA POWER AND LIGHT COMPANY ATLANTIC CITY ELECTRIC COMPANY SALEM NUCLEAR GENERATING STATION. UNIT NOS. 1 AND 2 DOCKET NOS. 50-272 AND 50-311

1.0 INTRODUCTION

l By letter dated February 11, 1997, as supplemented May 1, June 12, and July 23,1997, the Public Service Electric & Gas Company (the licensee) i submitted a request for changes to the Salem Nuclear Generating Station, Unit Hos. I and 2, Technical Specifications (TSs). These proposed amendments add a new TS, 3/4.7.10. " Chilled Water System - Auxiliary Building Subsystem," and an associated Bases section to address the support function this system provides to other necessary safety systems.

The licensee's supplemental letters provided additional information that did not affect the staff's proposed no significant hazards consideration determination.

2.0 BACKGROUND

2.1 Rationale for Requesting New TS During a recent reevaluation of the auxiliary building chilled water subsystem (ABCW), the licensee determined that ABCW may not be able to withstand a single failure and still perform its design support function if certain components are removed for maintenance. This could result in exceeding the design basis temperatures in the relay rooms, and eventually in the control room and the certain electrical equipment rooms. The excessive temperatures could render redundant trains of safety-related equipment inoperable.

The licensee reported this discovery in Licensee Event Report 97-002 on March 12, 1997. As a compensatory action, the licensee developed an operability determination to address the actions to be taken if less than three chillers or two chilled water pumps are operable. The licensee committed to keeping this operability determination in effect until a TS amendment is approved and implemented.

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(' The licensee determined that the new TS meets Criterion 3 of 10 CFR 50.36(c)(2). This criterion provides for "A structure, system, or component that is part of the primary success path and which functions or actuates to mitigate a Design Basis Accident or Transient that either assumes the failure of or presents a challenge to the integrity of a fission product barrier."

The Final Policy Statement on Technical Specifications Improvements for Nuclear Power Reactors (58 FR 39132) states, in part, "Also captured by this criterion are those support and actuation systems that are necessary for items in the primary success path to successfully function." The licensee determined that the ABCW subsystem removes heat from the control room envelope, relay rooms and electrical equipment rooms.

This heat removal is required for the primary success path to successfully function.

The licensee's sample review of the maintenance history showed that in the past, the chillers for the auxiliary building chilled water (ABCW subsystcm were out of service for corrective maintenance approximately once)per year.

The chilled water pumps were out of service for corrective maintenance approximately once every other year.

2.1 System Description

The licensee's June 12, 1997, supplemental submittal provided a detailed ABCW description (including a simplified system diagram) and also provided required operating modes and system interfaces.

For clarity, a brief summary of the information provided by the licensee is included in the following paragraphs.

The ABCW is a closed loop subsystem that removes heat from various safety-related and nonsafety-related equipment and rejects the heat to the ultimate heat sink through the service water system.

Each Salem unit has its own loop (the systems are cross connected; however, the cross connects are not utilized and not credited for mitigation).

Each unit's ABCW includes three 50% capacity (all three chillers are required for normal operation during maximum summer temperatures) liquid chillers (powered from separate AC vital buses) and two 100% capacity chilled water pumps (also, powered from separate AC vital buses).

The safety-related heat loads are:

control area air conditioning (CAAC) cooling coils (the control room envelope is comon for Salem Units 1 and 2) emergency air conditioning emergency control air compre(EAC) cooling coils ssor (ECAC) coolers The nonsafety heat loads are:

- penetration area cooler units (PACUs)

- main steam radiation monitors (R46s)

- miscellaneous room ccolers (Salem Unit 2's ABCW only)

3 The ABCW subsystem is required to operate in the following modes (1) normal, (2) abnonnal, (3) accident safety injection, (4) accident high radiation, (5) loss of offsite power, and (6) fire outside control room area.

3.0 EVALUATION The licensee is proposing the following new ABCW TS limiting condition for operation (LCO):

3.7.10 The chilled water system loop which services the safety-related loads in the Auxiliary Buildir.g shall be OPERABLE with:

a.

Three OPERABLE chillers b.

Two OPERABLE chilled water pumps The above equipment is required to be operable to provide the required redundancy to ensure that the system functions to remove post-accident heat loads, assuming a single failure. The licensee is proposing to have the above LCO applicable in all modes and during movement of irradiated fuel assemblies.

The licensee is proposing the following action statements in the event an LCO cannot be met:

H0 DES 1, 2, 3, and 4 a.

With one chiller inoperable:

1.

Remove the appro)riate non-essential heat loads from the chilled water system wit 11n 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> and; 2.

Restore the chiller to operable status within 14 days or; 3.

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 hours3.472222e-4 days <br />0.00833 hours <br />4.960317e-5 weeks <br />1.1415e-5 months <br />, b.

With two chillers inoperable:

1.

Remove the appro>riate non-essential heat loads from the chilled water system wit 11n 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> and; 2.

Align the control room emergency air conditioning system (CREACs) for single filtration operation using the [other Salem un< t's) train within 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> and;

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3.

Restore at least one chiller to operable status within 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> -

or; 4.

Be in at least NOT STAND 8Y 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 />, i

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With one chilled water pump inoperable, nston the chilled water puml: to operable status within 7 days or be in at least HOT STAN08Y witsin 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 />.

If one ABCW chiller is inoperable, actions must be taken to transfer heat loads to other systems and the inoperable chiller must be restored to operable-status within 14 days.

In this condition, two optrable ABCW chillers-are adequate to perform the accident-cooling function (three chillers are requind to perform the normal cooling function during certain sunner conditions). The l

14-day completion time is reasonable based on the low probability of an remainingABCWchillers..gduringthlstime,the100%capacityofthe

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initiating event occurrin the ability to transfer additional heat loads to the other salem unit's ABCW cnt11ers if necessary, and the licensee's-probabilistic safety assessment which shows an acceptable conditional core damage probability.

' f two ABCW chillers an inoperable, action must be taken to transfer heat loads to other systems and restore one of the: inoperable chillers to operable status within 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />. The 72-hour completion time is reasonable ba thelowprobabilityofaninitiatingeventoccurringduringthistime,sedon the requirement to transfer heat loads to other systems within 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br />, and the licensee's probabilistic safety assessment which shows an acceptable conditional core damage probability.

If the actions discussed above cannot be met, the unit must be in hot standb 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 />. y The allowed completion times are reasonable b reach the required unit conditions from full ased on operating experience, to manner and without challenging unit systems. power conditions ' n an orderly Witi one chilled water pump inoperable, action must be taken to restore the pump to operable status within 7 days.

In this condition, one operable ABCW pump is adequate to perform the accident cooling function. The 7-day completion time is reasonable ba eventoccurringduringthistIme,sedonthelowprobabilityofaninitiating the 100% capacity of the remaining ABCW pump, the ability to transfer some heat loads to the other Salem unit's ABCW subsystem, and the licensee's probabilistic safety assessment which shows on acceptable conditional =co n damage probability.

If these actions cannot be met,-the unit must_be in 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 folloeing 30 hours3.472222e-4 days <br />0.00833 hours <br />4.960317e-5 weeks <br />1.1415e-5 months <br />. The allowed r.ompletion times are reasonable, based on operating experience, to reach the required unit conditior.s from full power conditions in an orderly manner and without challenging unit systems.

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• For Modes 5 and 6 or during the movement of irradiated fuel assemblies, the licensee proposed similar action statements. However, the requirement to place the unit in hot standoy followed by cold shutdown is replaced by the requirement to suspend core alterations and movement of irradiated fuel assemblies.

This is an appropriate change to the action statements i

considering the plant conditions.

The licensee is proposing the following surveillance requirements (SRs) to verify ABCW operability:

4.7.10 The chilled water loop which services the safet l

the Auxiliary Building shall be demonstrated OPERMLE: y-related loads in At least once per 31 days by verifying that each manual valve in a.

the chilled water system flow path servicing safety related components that is not locked, sealed, or otherwise secured in i

position, is in its correct position.

b.

At least once per 18 months, by verifying that each automatic valve actuates to its correct position on a safeguards Initiation

signal, At least once per 92 days by verifying that each chiller starts c.

and runs.

Regarding the first SR above, verifying the correct alignment for manual valves in the ABCW flow path arovides assurance that the proper flow path exists for ABCW operation. 111s SR does not apply to valves that are locked, sealed, or otherwise se:ured in position, since they are verified to be in the correct position p.ior to locking, sealing, or securing.

This SR also does not appl valves. y to valves that cannot be inadvertently misalign % such as check This SR does not require any testing or valve manipulation; rather, it involves verification that those valves ca)able of potentially being mispositioned are in the correct position.

based on engineering judgment.

T.ie 31-day frequency is acceptable Regarding the second SR above, this SR verifies that each ABCW valve will actuate to its correct position on an actual or simulated safeguards initiation signal. The 18-month frequency allows for performing this surveillance during unit outages.

Regarding the final SR above, the verification of chiller operath.n ensures that a chiller previously in a standby condition will start, run and pick up the available heat load when required.

bassd on the operating history of the chillers.The 92-day frequency is appropriate Additionally, the licensee proposed TS bases to provide the rationale for the new TS. The staff found that the licensee's proposed bases provide an acceptable level of basis information for the operators' use.

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! Based on the above discussion, the staff finds the licensee's proposed TS revisions acceptable. However, the staff notes that the licensee's TS change request is not required to ensure public health and safety (dy ensured the licensee's former method of performinn operability determinations alrea adequate protection of pub'ic health and safety). However the licensee's proposal is a TS enhancement that will allow for a more ope,rator-oriented TS and a reduced chance for action statement induced plant transients entry into TS 3.0.3 and forced plant shutdowns will be minimized). (i.e.,

4.0 STATE CONSULTATION

In accordance with the Comission's regulations, the New Jersey State official was notified of the proposed issuance of the amendments. The State official had no comments.

5.0 ENVIRONMENTAL CONSIDERATION

The amendments change a requirement with respect to installation or u',e cf a facility component located within the restricted area as defined in 10 CFR Part 20 and change surveillance requirements. The NRC staff has determined that the amendments involve no significant increase in the amounts, and no significant change in the types of any effluents that may be released offsite, and that there is no s\\gnificant increase in individual or rumulative occupational radiation exposure. The Comission has previously issur,d a proposed findin consideration, g that the amendments involve no significant hazards and there has been no public coment on such finding (62 FR 11497). Accordingly, the amendments meet the eligibility criteria fcr categorical exclusion set forth in 10 CFR 51.22(c)(9).

Pursuant to 10 CFR 51.22(b) no environmental impact statement or environmental assessment need be prepared in connection with the issuance of the amendments.

6.0 CONCLUSION

The Comission has concluded, based on the considerations discussed above, that:

(1) there is reasonable assurance that the health and safet public will not be endangered by operation in the proposed manner,y of the (2)such activities will be conducted in compliance with the Comission's regulations, and (3 defense) the issuance of the amendments will not be inimical to the comon and security or to the health and safety of the public.

Principal Contributor:

S. Dembek Date:

July 29, 1997 N,-

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