ML20196J601

Safety Evaluation Supporting Amends 215 & 195 to Licenses DPR-70 & DPR-75,respectively

ML20196J601
Person / Time
Site:	Salem
Issue date:	12/02/1998
From:	NRC (Affiliation Not Assigned)
To:
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ML20196J589	List: ML20196J582 ML20196J601
References
NUDOCS 9812100143
Download: ML20196J601 (6)

Text

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j' NUCLEAR REGULATORY COMMISSION a

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SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION RELATED TO AMENDMENT NOS.215 AND 195 TO FACILITY OPERATING LICENSE NOS. DPR-70 AND DPR-75 I

PUBLIC SERVICE ELECTRIC & GAS COMPANY PHILADELPHIA ELECTRIC COMPANY

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DELMARVA POWER AND LIGHT COMPANY i

ATLANTIC CITY El FCTRIC COMPANY SALEM NUCLEAR GENERATING STATION. UNIT NOS.1 AND 2 i

I DOCKET NOS. 50-272 AND 50-311

1.0 INTRODUCTION

By letter dated August 12,1998, as supplemented on October 12,1998, the Public Service Electric & Gas Company (the licensee) submitted a request for changes to the Salem Nuclear Generating Station, Unit Nos.1 and 2, Technical Specifications (TSs). The requested changes would revise TS 3/4.6.1.3, " Containment Air Locks," to modify the action statements for an inoperable air lock. The amendments also revise (a) TS Bases 3/4.6.1.2, " Containment Leakage," to correct an editorial error, and (b) replace TS Bases 3/4.6.1.3, " Containment Air Locks," with a section that provides additional detail regarding the operation of the air locks. The October 12,1998, letter provided clarifying information that did not change the initial proposed no significant hazards consideration determination.

2.0 EVALUATION

Background

The containment structures at Salem are designed to provide: (a) a barrier to prevent the escape of radioactivity during normal and accident conditions, (b) protection against intemally-and/or extemally-generated missiles, (c) biological shielding during normal and accident conditions, and (d) seismic category I support for the reactor coolant and associated systems. The containment structure and all penetrations including the air locks are designed to withstand the loadings and peak pressures associated with the Design Basis Accident (DBA) in coincidence with a seismic event.

The Salem containment structures each include two personnel air locks that permit personnel to j

access / egress the containment while maintaining the integrity of the containment pressure boundary.' Each air lock consists of an approximately 9 ft. - 9 in. right circular cylinder that contains two doors forming a personnel chamber between the doors. Mechanical interlocks ensure that both doors cannot be opened at the same time. During Modes 1,2,3, and 4 (power 9812100143 981202

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2-operation, startup, hot standby, and hot shutdown), at least one of the doors must be closed.

During Modes 5 and 6 (cold shutdown and refueling), both doors may be opened at the same time after intentionally disabling the interlock mechanism. This is allowed unless core alterations are in progress or irradiated fuel assemblies are being moved.

Current TS Actions Reauired for Inocerable Air Lock i

Salem Unit 1 The Action statement for Salem Unit 1 TS 3.6.1.3 states that, with an air lock inoperable, the air lock must be restored to operable status within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> or the unit be in at least Hot 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 (Mode 5) within the following 30 hours3.472222e-4 days <br />0.00833 hours <br />4.960317e-5 weeks <br />1.1415e-5 months <br />.

Salem Unit 2 j

The Action statements for Salem Unit 2 TS 3.6.1.3 provide required actions in response to (a) one containment air lock door being inoperable, and (b) an inoperable air lock resulting from other than an inoperable door.

Should one air lock door become inoperable, TS 3.6.1.3 Action a. requires:

1. Maintain at least the operable air lock door closed and either restore the inoperable air l

lock door to operable status within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> or lock the operable air lock door closed.

2. Operation may continue until performance of the next required overall air lock leakage test provided that the operable air lock door is verified to be locked closed at least once per 31 days.

3. Otherwise, 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 />.

4. The provisions of TS 3.0.4 are not applicable.

Should an air lock become inoperable for other than an inoperable door, TS 3.6.1.3, Action b.

requires:

At least one air lock door be maintained closed, the inoperable air lock be restored to operable status within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> 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 hours3.472222e-4 days <br />0.00833 hours <br />4.960317e-5 weeks <br />1.1415e-5 months <br />.

Proposed Channes in its August 12,1998, letter, the licensee proposed changes to TS 3.6.1.3 to modify the action statements should an air lock become inoperable. The licensee stated that the proposed changes will provide the ability to continue operation if an air lock door or an air lock door intedock mechanism becomes inoperable. Thus, the operators would not be challenged by unnecessary plant shutdowns. The changes would also allow separate condition entry for each air loci:. Specifically, the proposed changes will provide distinct action statements for: (a) one or l

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more containment air locks with one air lock door inoperable; (b) one or more containment air locks with only the containment air lock intedock mechanism inoperable; and (c) one or more containment air locks inoperable for reasons other than (a) or (b). The proposed changes are consistent between both Galem units and consistent with the Actions detailed in NUREG-1431,

" Standard Technical Specifications - Westinghouse Plants," Revision 1, dated April 1995.

Evaluation The Limiting Conddions for Operation (LCOs) for TS 3.6.1.3 state that each containment air lock shall be operable in Modes 1,2, 3 and 4 with (1) both doors closed except when an air lock is being used for normal transit entry and exit through the containment, then at least one door shall be closed, and (2) an overall air lock leakage rate that is in accordance with the Containment Leskage Rate Testing Program (CLRTP). The CLRTP requires periodic leak rate testing of the seats on each air lock door as well as the leak rate testing of the complete air lock. Furthermore, the surveillance requirement associated with this TS requires testing of the interlock mechanism once per 6 months to verify that only one door in each airiock can be opened at a time.

The containment air locks are provided to permit personnel to enter and exit the containment while maintaining the integrity of the containment pressure boundary. Each air lock door has been designed and tested to certify its ability to withstand a pressure in excess of the maximum expected pressure following a DBA in containment. The design utilizes doors which open into the containment, such that an increase in the containment intamal pressure results in increased closing (seating) force on the door, and double gasketed door seals with pressure testing capability. Since each air lock contains two doors with a personnel chamber in between, containment pressure integrity, and hence containment operability, can be maintained with one operable door closed. The air lock door interlock mechanism ensures that both doors cannot be opened at the same tima during Modes 1 through 4, when containment integrity must be maintained. Thus, the door intedock supports containment operability while the air lock is being used for personnel transit in and out of containment. However, operability of the intedock mechanism is not required to support the operability of an airlock door.

The licensee proposed that the current Actions be replaced with the following Actions:

a.

One or more containment air locks with one containment air lock door inoperable.

1. Verify the operable door is closed in the affected containment air lock within 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br />, and:

2. Lock the operable door closed in the affected air lock within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />, and:

3. Verify the operable door is locked closed in the affected air lock once per 31 days.

Entry and exit is permissible for 7 days (from initial LCO entry) under administrative controls if one door is inoperable in each lock. Air lock doors in high radiation areas may be verified locked closed by administrative means.

b.

One or more containment air locks with only the containment air lock intedock mechanism inoperable.

1. Verify an operable door is closed in the affected air lock within 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br />, and:

2. Lock an operable door closed in the affected air lock within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />, and:

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3. Verify an operable door is locked closed in the affected s'r lock once per 31 days. Entry i

and exit of containment is permissible under the control of a dedicated individual for i

i the duration of the entry to ensure only one dooris open at a time. Air lock doors in

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high radiation areas may be verified locked closed by administrative means.

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c.

One or more containment air locks inoperable for reasons other than condition a or b.

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1. Immediately initiate action to evaluate overall containment leakage per LCO 3.6.1, and:

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2. Verify that at least one door is closed in the affected air lock within 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br />, and:

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3. Restore the air lock to operable status within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> 3

l d.

If the Actions and associated completion times of a., b., or c. cannot be met, be in Hot Standby within 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 NRC staff finds that the actions in response to an inoperable door or intedock ensure that a i

leak tight containment barrier is maintained by the use of an operable air lock door. For Actions j

a. and b., the 1-hour time period to complete the verification that an operable door is closed is j

consistent with the Action of LCO 3.6.1.1, which requires that containment be restored to l

operable status within 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br />. The 24-hour completion time for locking the operable air lock door is acceptable since th'e operable door of the affected air lock is being maintained closed.

Verification that the door remains locked once per 31 days is adequate in view of the low likelihood of a locked door being mispositioned and other administrative controls in place. The verification of doors in high radiation areas by use of administrative means is acceptable since access to these areas is typically restricted and the probability of misalignment of the door, once it has been verified to be locked in the proper position, is small. Additionally, the staff finds the j

7-day allowance for containment entry if both air locks each have an inoperable door is acceptable due to the low probability of an event that could pressurize the containment during the short time that the operable door is expected to be open.

For the situation of an inoperable door interlock mechanism, the staff finds that entry into and exit from containment under the control of a dedicated individual stationed at the air lock to ensure that only one door is opened at a time is acceptable since the individual performs the function of the interlock.

l In the event that an air lock is inoperable for reasons other than in Actions a. and b., the staff finds that the proposed Actions are acceptable. The evaluation of the overall containment leakage, using current air lock test results, ensures that the containment is operable in that the overall leakage does not exceed the limits specified in the CLRTP. The time to verify one door in the affected air lock is closed within 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> is consistent with the Achons of LCO 3.6.1 which ensure that the containment is restored to operable status within 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br />. Additionally, the time to restore the affected air lock (s) to operable status within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> is acceptable since at least one door is maintained closed in the affected air lock.

If the inoperable air lock cannot be restored to operable status within the required completion time, the allowed completion times to complete the plant shutdown are consistent with the times required in other TSs and with operating experience to reach the required plant conditions from full power operation in an orderty manner without challenging plant systems.

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, The licensee proposed that the Actions be modified by five notes. Note (1) allows entry and exit to perform repairs on the affected air lock component. If the outer door is inoperable, then it may be easily accessed for most repairs. If repairs are required on the interior door, it is preferred that the air lock be accessed from inside primary containment by entering through the operable air lock. However, if this is not practicable, or if repairs on either door must be performed from inside of the air lock, then it is permissible to enter the air lock through the operable door. This means that there is a short period of time during which the containment boundary is not intact (during access through the operable door). The ability to open the operable door, even if it means the containment boundary is temporarily not intact, is acceptable due to the low probability of an event that could pressurize containment during the short time in which the operable door is expected to be open. After each entry and exit, the operable door must be immediately closed.

Note (2) adds clarification that separate condition entry is allowed for each air lock. This is acceptable, since the required Actions provide appropriate compensatory measures for each inoperable air lock.

Notes (3) and (4) ensure that only the required Actions and associated completion times of Action c. are required if both doors in the same air lock are inoperable. With both doors in the same air lock inoperable, an operable dooris not available to be closed. Required Actions c.1 and c.2, which require immediate evaluation of overall containment leakage and closing at least one door in the affected air lock respectively, are the appropriate remedial actions.

Note (5) adds clarification that the Conditione and Actions in TS 3.6.1, " Primary Containment,"

must be entered when the air lock leakage is determined in Action c.1 to result in exceeding the overall containment leakage rate.

The staff also finds that the proposed changes to the TS Bases considerably expand the information that is presented. Additionally, the revised Bases provide detailed information that is consistent with, and satisfactorily supports each of the new Action statements.

3.0 STATE CONSULTATION

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

4.0 ENVIRONMENTAL CONSIDERATION

The amendments change a requi.ement with respect to installation or use of a facility component located within the restricted area as defined in 10 CFR Part 20. 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 significant increase in individual or cumulative occupational radiation exposure. The Commission has previously issued a proposed finding that the amendments involve no significant hazards consideration, and there has been no public comment on such finding (63 FR 48265). Accordingly, the amendments meet the eligibility criteria for categorical exclusion set forth in 10 CFR 51.22(c)(9). Pursuant to 10 CFR 51.22(b) no environmentalimpact statement or environmental assessment need be prepared in connection with the issuance of the amendments.

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5.0 CONCLUSION

The Commission has concluded, based on the considerations discussed above, that: (1) there is reasonable assurance that the health and safety of the public will not be ondangered by operation in the proposed manner, (2) such activities will be conducted in compliance with the Commission's regulations, and (3) the issuance of the amendments will not be inimical to the common defense and security or to the health and safety of the public.

Principal Contributors: D. Collins P. Milano Date: December 2, 1998