ML20080R473

Safety Evaluation Supporting Amends 161 & 165 to Licenses DPR-24 & DPR-27,respectively

ML20080R473
Person / Time
Site:	Point Beach
Issue date:	03/06/1995
From:	Office of Nuclear Reactor Regulation
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ML20080R468	List: ML20080R465 ML20080R473
References
NUDOCS 9503090317
Download: ML20080R473 (8)

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UNITED STATES yi

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' NUCLEAR REGULATORY COMMISSION E

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WASHINGTON. D.C. 2006H001 1

SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION RELATED TO AMENDMENT NOS.161 AND 165 TO FACILITY OPERATING LICENSE NOS. DPR-24 AND DPR-27 WISCONSIN ELECTRIC POWER COMPANY POINT BEACH NUCLEAR PLANT. UNIT NOS. 1 AND 2 DOCKET NOS. 50-266 AND 50-301

1.0 INTRODUCTION

By letter dated December 22, 1994, Wisconsin-Electric Power' Company (WEPCO),

the licensee, requested an amendment to Facility Operating License Nos. DPR-24' and DPR-27 for PBNP Units 1 and 2, respectively. - Supplemental information was provided by letters dated February 1, 1995, and February 21, 1995. 'The submittal proposed changes to Technical Specification (TS) Sections 15.3.3,

" Emergency Core Cooling. System, Auxiliary Cooling Systems, Air Recirculation Fan Coolers, and Containment Spray;" 15.3.4, " Steam and Power Conversion System;" 15.3.5, " Instrumentation System;" 15.3.7, " Auxiliary Electrical Systems;" 15.3.14, " Fire Protection System;" and 15.4.1, " Operational Safety f,

Review." The proposed changes would allow a one-time exception' for one Train A service water pump, operating with power supplied by the alternate-shutdown system B08/B09 480-volt buses, to be considered operable during the Unit 1 1995 refueling outage, and to remove or revise some one-time exceptions that are no longer necessary or appropriate.

In addition, the bases for TS Section 15.3.7 would be modified to be consistent with the TS-changes, and the bases for TS Section 15.3.3 would be modified to be consistent with Amendment Nos. 159 and 163, which were issued on December 21, 1994.

2.0 BACKGROUND

The Point Beach Nuclear Plant (PBNP) is a two-unit site and was originally designed and provided with a total of two emergency diesel' generators (EDGs),.

one-for each train of the engineered safety features. Consequently, any time-an EDG was out of service, a dual unit Limiting Condition of Operation (LCO) would be imposed.

The licensee is in the process of modifying.the emergency electrical power distribution system including.the installation of two i

additional EDGs. This modification of the distribution system will allow the removal of one EDG frem service without entering an LCO. This new electrical system design was previously reviewed and approved by the NRC staff.

The connection of the output of one of the additional emergency diesel generators into the existing electrical system took place during the fall 1994 i

Unit 2 refueling outage. During the Unit I spring 1995 refueling outage, additional modifications to the electrical systems and connection of the second EDG will take place.

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~i In addition, during the'next two refueling outages (Unit 1. spring 1995:and.

l Unit. 2 fall 1995)~ WE 'is planning to perform modifications that will change thes L

logic of the 4160-volt safeguards-bus loss of voltage protection from 1-out-of-2. to : 2-out-of-3.- Therefore, the TSs will be modified to. account for this new design.

If.a problem occurs such that these modifications cannot.be completed during these outages as planned, the proposed specifications are E

stated in such a manner that it will allow the completion in future. outages.

2.0 EVALUATION TS Section 15.3.3. "Emeraency Core Coolino System. Auxiliary Coolino Systems.

Air Recirculation Fan Coolers. and Containment Sorav"-

j The licensee proposed to' revise the footnote associated.with TS Section 15.3.3.D.I.a regarding service water system-(SWS) pump operability.

The.

footnote referred to was removed by Amendment Nos. 159 and-163 for Units I and 2, respectively, dated December 21,-1994, as it only applied to the fall; q

1994 refueling outage. The contents of this footnote, and the proposed i

revision, are discussed below.

The SWS at PBNP consists of 6 pumps (designated as P32A, B, C, D, E, and F) shared by both units.

The emergency power supplies'for these SWS pumps are arranged in the following configuration:

For Unit 1:

Train A emergency diesel generators (EDGs) provide power to the 4160-volt bus IA05, which in (trn provides power to 480-volt bus 1803 that in turn powers two SWS pumps, P32A and P328.

Train B EDGs provide power to the 4160-volt bus IA06, which in turn provides power to 480-volt bus 1804 that in turn powers one SWS pump, P32C.

7 For Unit 2:

Train B EDGs provide power to the 4160-volt bus 2A06,.which in, turn provides power to 480-volt bus 2B04 that in. turn powers two SWS pumps, P32D and P32E.

Train A EDGs provide power to the 4160-volt bus 2A05, which in turn provides power to 480-volt bus 2B03 that in turn powers one SWS pump, P32F.

For Unit I to be made critical, TS Section 15.3.7.A.1 1 requires that the 4160/480-volt buses IA05/lB03, IA06/lB04, and 2A06/2804 are operable and the i

buses are energized from their normal power supply.

For Unit 2 to be made.

j critical, TS Section 15.3.7.A.I.k requires that the 4160/480-volt buses 2A05/2B03, 2A06/2B04, and 1A05/IB03 are operable and the buses are energized i

from their normal power supply.

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For either unit to be made critical, TS Section 15.3.3.D.I.a requires that four SWS pumps are operable. However, TS Section 15.3.3.D.2.a allows.one of the four required SWS pumps to be out-of-service provided a pump is restored 1

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

The first additional.EDG (G-04) was connected into the existing emergency electrical distribution system during the Unit 2 refueling outage in the fall of 1994, while Unit I-was in power operation. That resulted in Train B SWS pumps (P32D and P32E) not having a safety-related emergency power supply during the period of-the emergency electrical power system modification, which lasted longer than the above cited TS allowable outage time of 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> for the SWS pumps. The work performed to connect the EDG into the existing emergency electrical distribution system was expected to last more than four days. Therefore, prior to this effort, the following footnote was proposed to be added to TS Section 15.3.3.D.I.a:

"During the Unit 2, 1994 refueling outage, one Train B' service water pump operating with power supplied by the alternate shutdown system, 808/B09 480 volt buses, may be considered operable from a normal (offsite) power. supply under the provisions of Technical Specification 15.3.0.C."

This footnote was necessary in order to allow the safe continue'd. operation of Unit I without entering an LCO while the work performed to connect EDG G-04 was taking place. Without this one-time exception, the scheduled modification would require a dual unit outage.

The staff (stated in a Safety Evaluation dated September 23, 1994) found the above one-time exception to TS Section 15.3.3.D.1.a acceptable.

The connection of the second additional EDG (G-03) into the existing emergency electrical distribution system is scheduled to take place during the Unit 1 refueling outage in the spring of 1995.

Therefore, the licensee proposed to revise the above footnote to read:

"During the Unit 1, 1995 refueling outage, one Train-A service water pump operating with power supplied by the alternate shutdown. system, 808/B09 480 volt buses, may be considered operable from a normal (offsite) power supply under the provisions of Technical Specification 15.3.0.C."

Three train B service water pumps powered by the 1B04 and 2B04 buses will remain unaffected by the reconfiguration and bus-tie work. The one service water pump powered from 2B03 bus will be unaffected, except that the standby.

emergency power source will be considered inoperable. One of the two service water pumps powered from 1B03 will be removed from service to prevent potential overload, and the other will be powered'by the alternate shutdown system buses.

The footnote added to TS Section 15.3.3.D.I.a is only for clarification of the existing TS, since the service water pump supplied by the alternate shutdown system would be considered operable under existing TS Section 15.3.0.C.

This Section states that the component is " considered operable for the purpose of satisfying the requirements of the applicable

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l Limiting Conditions of Operation, provided...the alternate power source (normal or emergency) is operable."

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~ Based on:its review of the above rationale, which is similar to that stated in the previous safety Evaluation (dated September 23,1994), the ' staff concludes

,that-the proposed footnote associated with TS Section 15.3.3.D.I.a poses no L-undue risk to public health' and safety, and involves ~no'significant increase.

in the consequences of an accident previously evaluated. Therefore, the staff finds it acceptable.

By letter dated February 1,1995, the licensee proposed to change the bases to l

TS Section 15.3.3 to make them consistent with Amendment Nos. 159 and 163, issued on December 21, 1994. The new text would state:

"When the failures involve the residual heat removal system, in order to insure redundant means of decay heat removal, the reactor system may remain in a condition.with reactor coolant temperatures greater than 350*F so that the reactor coolant loops and associated steam generators may be utilized for redundant decay heat removal."

i The bases currently state "... temperatures between 500 and 350*F...," which corresponds to the TS prior to Amendment Nos. 159 and 163. The staff agrees with the licensee' that the proposed change accurately reflects the current TSs. Therefore, this change is acceptable, i

TS Section 15.3.4. " Steam and Power Conversion System" The licensee proposed to delete the following footnote associated with TS Section 15.3.4.C.2 regarding motor driven auxiliary feedwater pump operability:

"During the Unit 2, 1994 refueling outage, P-38B,-the Train B motor driven auxiliary feedwater pump, may be out-of-service.for up to 12 days."

This proposed change will remove a one-time exception from the TSs that is no longer applicable.

Since this change is administrative, the staff finds it acceptable.

TS Table 15.3.5-3. "Encineered Safety Features" The existing design of the loss of voltage protection (which causes the opening of the normal safeguards power supply breaker, starting of the associated EDG, and providing a permissive for the closure of the EDG output breaker to repower the buses that have lost voltage) uses two channels per bus

j with the trip of one channel causing the protection ections (1-out-of-2).

i The licensee has proposed to change Table 15.3.5-3, Specification 4.a.ii to include requirements for 2-out-of-3 logic for the loss of voltage function.

This is being done by specifying the following for the 2-out-of-3 logic row:

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p Column 1 No. of Channels

-3/ bus Column.2_

No. of Channels to trip 2/ bus' Column 3 Min. Operable Channels-2/ bus Column 4 Permissible Bypass Conditions None Operator Action if Conditions of Col. 3 cannot be met -

In addition, the licensee has proposed.to add a new note associated with.

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"*****" for the loss of voltage relay protection function as follows:

• • • • • • - Use the 3/ bus specification for each A05 orlA06 bus that has been modified to the 2-out-of-3 logic for the..

loss of voltage protection function."

This note requires the appropriate row for 1-out-of-2 and 2-out-of-3 protection logic to be used for determining if an LC0 should be entered.

The licensee also proposed to change the note associated with "***" as follows:

Declare the standby emergency power supply inoperable for the affected bus. The applicable Limiting Condition for Operation (LCO) shall be entered.

Separate LCOs may be entered for.the Degraded Voltage and Loss of Voltage functions."

This change is necessary to incorporate the revised nomenclature for emergency diesel generators which is " standby emergency power supply."

This design is being changed to three channels per bus with the trip of two c

channels causing the protection actions (2-out-of-3).

This change-to the design meets the existing design requirements as defined in. the Point Beach' FSAR.

In addition, it. improves the design with respect to inadvertent actuations. When any single channel is taken out of service for testing, maintenance, or calibration, that channel can be placed in the trip condition and the remaining logic is such that actuation of the protection function can -

still occur on the trip of either. of the remaining operable channels.

Therefore, during this time period the logic can still meet the sin.gle failure criterion and a limiting condition for operation does not have to be entered.

The proposed TS changes for this protection function will require that at least two channels are operable.

If less than two channels are operable, the applicable limiting condition for operation for the standby emergency power supply for that bus shall be entered. These. requirements are appropriate for this protection logic and consistent with TS requirements for other 2-out-of-3 protection logic systems. 'Therefore, the staff finds these changes acceptable.

TS Section 15.3.7. " Auxiliary Electrical Systems" The licensee has proposed to delete-Specification 15.3.7.A.1.d that states, "Both units' A05/A06 bus tie-breakers are removed from their cubicles." Also

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proposed;isL the' deletion of the references to the A05 and A06 tie-breakerslin -

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p?"QR, LSpecifications 15.3.7..B.I.diand e. JThese changes are'necessary because the R

tinstallation of additional' EDGs will' eliminate the A05/A06 tie-breaker p y icapability.:

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The main purpose of the!A05/A06 bus' tie ~ capability!atLPoint/ Beach was for?

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. maintaining; electrical ~ powergto either safeguards busiwhile the-' normal power. T >

l supply for either bus was out-of-service.for maintenance. :The bus, tie,

d capability;fn,the1480-voltisafeguards buses remains and'is?sufficientJforf

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1 1 maintaining continuity.-of electrical service to the desired loads,during.

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periodsLwhen: electrical, power tof either safeguards ~ bus:is out-of-service fori t H

. maintenance. Withi the removal; of the bus tie" capability for the' 4160-volt safeguards buses, the. deletion of the' associated Technical Specifications <is:

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. appropriate,.and is therefore' acceptable.

The licensee proposed to delete the.following' footnote' associated withiTS.

.Section 15.3.7.B.I.h. regarding, the. allowed out-of-service; time for power. i supplles:;

i "During the' Unit 2, 1994Erefueling outage', standby emergency power to:

9j Unit 1 A06/B04 and Unit 2 A06/B04 may be out-of-service for up to 12:

4 days."

This proposed change will remove a one-time exception from~the TSs that islno E

longer applicable.

Since this; change is administrative, theistaff finds it:

acceptable.

The licensee proposed to add t'he following new EDG (G-03'and.G-04) ventilation system limitations to the ' bases'of TS-Section 15.3.7:

"DR for G-03 andLG-04,'only the large capacity fan (W-183C for G-03,

W-184B for G-04) is operable:and outside air temperature is <84*F orlif-the small capacity.. fan (W-183B for. G-03, W-184C ;for G-04) -is1 operable and outside air; temperature is $36*F."

This proposed change'provides conservative limitations.for operability of the new EDGs with either the large. capacity or small capacity fan out-of-service.

Since this is conservative,renhancing1 safety, the staff finds it acceptable.

q TS' Table 15.3.14-1. " Safe Shutdown' Area Fire Protection" The licensee proposed to add Line Item 21 to Table 15.3.14-1 to include.the G01/G02 fuel oil transfer pump room in the new EDG building in the shutdown p

area fire protection. table.

.The licensee stated that this proposed change is necessary because the fuel oil transfer system for.the G01 and G02 EDGs is being changed to'use.the;new

fuel oil transfer system as part of the modification to ' install. additional EDGs. The staff finds this proposed change appropriate and consistent with the design. Therefore, it is acceptable.

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S Table 15.'4.1-1. '" Minimum Freauencies for-Checks. Calibrations. and Tests of 1

Lnstrument Channels" p

- The licensee has proposed"to change TS Table'15.4.1-1, Number 13, _to remove the "(1)" from the monthly.; test requirements... This1TS currently allows 'an n

exception from performing-the-required' testing. of the degraded voltage and 6

loss of voltage protection relays during periods of refueling.-~This-exception z1 is not considered to be appropriate because this~ testing should be continued-

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' j to verify operability of shared equipment that_. supports operation of-the 1

6 operatingiunit... The. removal of these exceptions 1s an improvement in the safe :

j operation of Point Beach because it will provide the appropriate requirements for testing of these shared protection features. Therefore, this change is s

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acceptable.

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Additional Comments l7 This amendment request, which allows-a one-time exception for one Train A-

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service water pump, operating with power supplied by the alternate shutdown system B08/B09 480-volt buses, to be considered operable during the Unit 1-1995 refueling outage, and which removes some exceptions that arelno longer necessary or_ appropriate, is a plant _ specific'iss'ue based on design and operational' characteristics of the Point Beach Nuclear Plant.

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Based on its review, the staff agrees with thel licensee that the proposed

. changes will not create a significant increase in.the probability.or.

consequences of:an accident previously evaluated. ~ The modifications and 1

changes do not create'new or different accident initiators or sequences,:or a significant reduction in a margin of safety. The modification ~to change the-

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loss of voltage protection function from 1-out-of-2 logic to. 2-out-of-3 logic I

on each bus continues to meet the original plant design bases and provides some improvement over the original design. Therefore, the proposed changes

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are acceptable.

3.0 STATE CONSULTATION

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

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4.0 ENVIRONMENTAL CONSIDERATION

- These amendments change a requirement with respect to the installation or use-

' of. a facility component located within the restricted ' area' as' defined in 10-CFR'Part 20 and changes surveillance requirements. The staff has determined that the amendments involve no significant increase in the amounts, and no

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- significant change in the types, of any effluents that may be released.offsite,

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' and that there is no significant increase in individual or cumulative occupa-H tional radiation exposure. The Commission has previously published a proposed-finding that these amendments involve no significant hazards consideration-and

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there has been no public comment'on.such finding (60 FR 6316). Accordingly, these amendments meet the eligibility criteria for categorical exclusion set a

forth in 10 CFR 651.22(c)(9).

Pursuant to 10 CFR 51.22(b), no environmental t

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(impa'ct'statementfor environmental assessment need'be prepared in connection

-with the issuance of these amendments.

s 5 '. 0 [0NCLUSION

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The staff-has concluded, based on the considerations discussed above, that.(1):

~ there Lis. reasonable assurance that the health and safety of the public will not be endangered by

.will. be conducted in. operation in the aroposed manner. (2):such activities compliance with tie Commission's regulations, ~and (3)' the; s

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:

S. Saba-D. Shum Date: March 6, 1995 l

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