ML20212H996

Safety Evaluation Supporting Amend 233 to License NPF-3

ML20212H996
Person / Time
Site:	Davis Besse
Issue date:	06/22/1999
From:	NRC (Affiliation Not Assigned)
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ML20212H994	List: ML20212H990 ML20212H996
References
NUDOCS 9906280266
Download: ML20212H996 (6)

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UNITED STATES 4-j NUCLEAR REGULATORY COMMISSION o

WASHINGTON, D.C. 300ss com l

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. SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION RELATED TO AMENDMENT NO.

O FACILITY OPERATING LICENSE NO. NPF-3 FIRSTENERGY NUCLEAR OPERATING COMPANY DAVIS-BESSE NUCLEAR POWER STATION. UNIT NO.1 DOCKET NO. 50-346

1.0 INTRODUCTION

By letter dated October 27,1998, Toledo Edison Company, Centerior Service Company, and

= The Cleveland Electric illuminating Company (the licensees at the time of the submittal),

submitted a request for changes to the Davis-Besse Nuclear Power Station, Unit No.1, Technical Specifications (TSs). FirstEnergy Nuclear Operating Company (FENOC) became the sole licensed operator on January 1,1999.

The proposed amendment would relocate a TS surveillance requirement (SR) from TS Section 3/4.6.5.1, " Shield Building - Emergency Ventilation System" to TS Section 3/4.6.5.2, " Shield Building Integrity." Administrative and bases changes would also be made.

By letter dated March 19,1999, the licensee revised the application, making a minor change that did not affect the staff's proposed determination of no significant hazards considerations.

This revision to the application deleted a clarification statement that had been proposed in the initial application, but had been found to be unnecessary.

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2.0 BACKGROUND

The shield building is discussed in the Davis-Besse Updated Safety Analysis Report (USAR),

Section 3.8.2.2, " Design of Seismic Class I and ll Structures - Shield Building," Section 6.2.1.

" Containment Systems - Containment Vessel Functional Design," Section 12.2.2.1, " Ventilation -

i Shield Building and Penetration Rooms," and Section 15.4.6, " Class 3 - Design Basis Accidents

- Major Rupture of Pipes Containing Reactor Coolant Up To and including Double-Ended Rupture of the Largest Pipe in the Reactor Coolant System (Loss-of-Coolant Accident)." The emergency ventilation system (EVS) is discussed in USAR Section 6.2.3, " Containment l

Systems - Containment Vessel Air Purification and Cleanup System,"in addition to Sections 12.2.2.1 and 15.4.6.

As stated in the USAR, the shield building encloses the containment vessel, the personnel access openings, the equipment hatch, and the portion of all penetrations that are associated 9906280266 990622 PDR ADOCK 05000346 P

PDR

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with primary containment. This building provides for biological shielding, controlled release of the annulus atmosphere under accident conditions, and environmental protection of the

- containment vessel.

' The EVS is intended for use in an accident situation to provide a negative pressure in the

. annulus between the shield building and the containment vessel, the penetration rooms, and the emergency core cooling system equipment rooms, and to reduce airborne fission product leakage to the environment by filtration prior to release of air through the station vent.

The EVS has two redundant, independent subsystems, each capable of meeting the functional requirement. A single failure of an active component in either subsystem does not affect the functional capability of the other subsystem. Each subsystem includes prefiiters, higharfficiency particulate air (HEPA) filters and charcoal adsorbers to remove airborne particles and methyliodide as well as elemental iodine contaminants resulting from a loss-of-coolant accident.

During normal operation, the EVS is in standby mode. An SFAS (safety features actuation system) signal actuates the fans, and control room instrumentation monitors the operation. The fans can be operated on emergency diesel generator power.

3.0 EVALUATION Currently, if shield building integrity is not adequate, both trains of EVS must be declared inoperable, so that TS 3.0.3 must be entered, which requires the initiation of a plant shutdown within 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br />. _ The licensee is proposing to relocate the portion of the EVS TS addressing L negative pressure capability to the shield building integrity TS. The principal effect of this relocation would be the extension of the time to initiate a plant shutdown (due to a loss of negative pressure capability) from 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> to 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />.

Each proposed change is discussed below.

3.1 IS_Indag

. The licensee proposes to delete the definitions index item " Shield Building Integrity." This is an administrative change consistent with the change discussed in Section 3.2. Therefore, it is

- acceptable.

3.2 TJ Definitions The licensee proposes to delete the " Shield Building Integ'ity" definition, which reads:

.1.24 SHIELD BUILDING INTEGRITY shall exist when; a.

The airtight doors and blowout panels listed in Table 4.6-1 are closed except the alitight doors may be used for normal transit entry and exit.

b.

The emergency ventilation system is OPERABLE.

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The sealing mechanism associated with each penetration (e.g.,

welds, bellows or O-rings) is OPERABLE.

The text of TS 1.24.a is also included in Shield Building Integrity TS SR 4.6.5.2. Therefore, the deletion of TS 1.24.a is acceptable.

. TS 1.24.b states that Shield Building Integrity requires the EVS to be operable. The licensee proposes to remove this dependency. As currently written, to satisfy Definition 1.24.b, only one l

train of EVS needs to be operable (TS 3.6.5.1 allows 7 days to restore one inoperable EVS train or initiate a shutdown). If both trains of EVS are inoperable, then TS 3.0.3 must be entered, which requires the initiation of a plant shutdown within 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br />. This 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> to initiate shutdown is L

more restrictive than the 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> allowed in TS 3.6.5.2 for loss of shield building integrity (due to both trains of EVS being inoperable as stated in TS Definition 1.24.b). Hence, TS Definition 1.24.b is not needed and its removal is acceptable.

The text of TS 1.24.c is also included in Containment Integrity TS 1.8.e, which refers to the same penetrations as Shield Building Integrity TS 1.24.c. If a sealing mechanism is not operable, then Containment Integrity TS 3.6.1.1 requires a plant shutdown to be initiated within 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br />. Since this is more restrictive than Shield Building integrity TS 3.6.5.2 (which requires the initiation of a plant shutdown within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />), and since both are applicable in Modes 1,2,3 and 4 only, TS 1.24.c is not necessary. Therefore, its deletion is acceptable.

Since the term " SHIELD BUILDING INTEGRITY" is only referred to in the shield building integrity TS and since the removal of each subpart of the definition is acceptable, the deletion of i

this definition is acceptable.

3.3 TS 4.6.5.1. " Containment Systems - Shield Buildina - Surveillance Reauirements" TS 4.6.5.1.d.4 currently reads:

4.

Verifying that each system products a negative pressure of greater than or equal to 0.25 inches Water Gauge in the annulus within 4 seconds after the fan attains a flow rate of 8000 cfm *10%. This test is to be performed with the flow path l

established prior to starting the EVS fan,' and the other dampers associated with the negative pressure boundary closed.

l The licensee proposes to move this TS from the EVS surveillance requirements to TS 4.6.5.2 as l

part of the shield building integrity surveillance requirements. EVS TS 3.6.5.1 requires that two independent EVSs be operable. Currently, without shield building integrity, both trains of EVS would have to be declared inoperable due to the loss of the capability to produce an acceptable negative pressure. TS 3.0.3 would then be entered, requiring a plant shutdown to be initiated l

within 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br />.

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f With a loss of shield building integrity, TS 3.6.5.2 allows 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> to restore integrity or immediately initiate a shutdown. Therefore, the proposed move of TS 4.6.5.1.d.4 has the effect of increasing the allowed restoration time from i hour to 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />, during which time the plant would be without shield building integrity though the EVS would still be considered operable since the negative pressure criteria would no longer be applicable.

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Maintaining shield building integrity ensures that the release of radioactive material from the primary containment atmosphere is restricted to those leakage paths and associsted leakage rates assumed in the accident analysis. The staff has determined that increasing the restoration time from i hour to 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> still provides a reasonable completion time considering the limited leakage design of the containment and the low probability of a design basis accident during this time period. Therefore, moving TS 4.6.5.1.d.4 from the EVS surveillance requiremc"s to the shield building integrity surveillance requirements is acceptable.

The licensee also proposes to delete the word "and" from TS 4.6.5.1.d.3 and insert "and" into TS 4.6.5.1.d.2. This is an administrative change only and is therefore acceptable.

3.4 TS 3.6.5.2. " Containment Systems - Shield Buildina Intearity - Limitina Condition for Ooeration" TS 3.6.5.2 currently reads:

.3.6.5.2 SHIELD BUILDING INTEGRITY shall be maintained.

APPLICABILITY: MODES 1,2,3 and 4 ACTION:

Without SHIELD BUILDING INTEGRITY, restore SHIELD BUILDING INTEGRITY 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 />.

The licensee proposes to change " SHIELD BUILDING INTEGRITY" to " shield building integrity."

Since this is consistent with the removal of the shield building integrity definition discussed in Section 3.2, this is an administrative change only and is acceptable.

3.5' TS 4.6.5.2. " Containment Systems - Shield Buildina Intearity - Surveillance Recuirements The licensee proposes to change " SHIELD BUILDING INTEGRITY" to " Shield building integrity" in TS 4.6.5.2, and renumber the current requirement TS 4.6.5.2.1. These are administrative changes consistent with other approved changes and are therefore acceptable.

The licensee proposes to add TS 4.6.5.2.2, which will read:

4.6.5.2.2 Shield building integrity shall be demonstrated at least once per REFUELING

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INTERVAL by verifying that each Emergency Ventilation System train produces a i

l negative pressure of greater than or equal to 0.25 inches Water Gauge in the annulus within 4 seconds after the fan attains a flow rate of 8000 cfm i 10%. This test is to be performed with the flow path established prior to starting the EVS fan, and the other dampers associated with the negative pressure boundary closed.

This addition was addressed in Section 3.3 where the staff accepted the move of this TS from the EVS surveillance requirements to TS 4.6.5.2.2 as part of the shield building integrity surveillance requirements. Hence, this new TS is acceptable.

The licensee also proposes changes to some of the language at the beginning of this TS (to be consistent with the remainder of the shield building integrity specifications) without altering the content. Therefore, these language changes are administrative only and are acceptable.

3.6 TS Table 4 6-1. " Access Ooeninas Reauired to be Closed to Ensure Shield Buildina Intearity" The description of air tight door no. 307 currently reads:

Access Door from Corridor 304 to the No. 3 Mechanical Penetration Room (Room 308)

The licensee proposes to change the description to reference Room 303 (from Room 308),

consistent with plant construction. This is an administrative change only and is acceptable.

3.7 TS Bases 3/4.6.5.1. "Emeroency Ventilation System" The licensee proposes to add the following text to this bases:

The proper functioning of the EVS fans, dampers, filters, adsorbers, etc., as a system is verified by the ability of each train to produce the required system flow rate.

j This provides clarification that EVS operability does not depend on the ability to provide an acceptable negative pressure, consistent with the other changes already reviewed. Therefore, this addition is acceptable.

3.8 TS Bases 3/4.6.5.2. " Shield Buildina Intearity" The licensee proposes to change " SHIELD BUILDING INTEGRITY" to " shield building integrity."

Thb is an administrative change only and is acceptable.

The licensee also proposes to insert the following text:

in the event shield building integrity, including the capability of the EVS to provide a negative pressure of greater than or equal to 0.25 inches Water Gauge, is not maintained, shield building integrity must be restored within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />. Twenty-four hours l

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is a reasonable completion time considering the limited leakage design of the containment and the low probability of a Design Basis Accident occurring during this time period.

This addition provides clarifying information consistent with the proposed TS changes and is therefore acceptable.

4.0 STATE CONSULTATION

~ In accordance with the Commission's regulations, the Ohio State official was notified 'of the proposed issuance of the amendment. The State official had no comments.

5.0 ENVIRONMENTAL CONSIDERATION

This amendment changes a requirement with respect to installation or use of a facility component located within the restricted area as defined in 10 CFR Part 20 or changes a 1

surveillance requirement. The staff has determined that the amendment involves no significant increase in the amounts, and no significant change in the types, of any effluent 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 amendment involves no significant hazards consideration, and there has been no public comment on such finding (63 FR 64125). Accordingly, the amendment meets the eligibility criteria for 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 amendment.

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6.0 CONCLUSION

The staff 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 endangered by operation in the proposed manner; (2) such activities will be conducted in compliance with the Commission's regulations; and (3) the issuance of this amendment will not be inimical to the common defense and security or to the health and safet of the public.

Principal Contributor: A. Hansen Date: June 22, 1999 j

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