ML20217D379

Safety Evaluation Supporting Amends 58 & 44 to Licenses NPF-87 & NPF-89,respectively

ML20217D379
Person / Time
Site:	Comanche Peak
Issue date:	04/20/1998
From:	NRC (Affiliation Not Assigned)
To:
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ML20217D356	List: ML20217D350 ML20217D379
References
NUDOCS 9804240290
Download: ML20217D379 (7)

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a UNITED STATES bj NUCLEAR REGULATORY COMMISSION 2

WASHINGTON, D.C. 20066-0001

• • • • • ,o l

SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION RELATED TO AMENDMENT NOS. 58 AND 44 TO FACILITY OPERATING LICENSE NOS. NPF-87 AND NPF-89 TEXAS UTILITIES ELECTRIC COMPANY l

COMANCHE PEAK STEAM ELECTRIC STATION. UNITS 1 AND 2 DOCKET NOS. 50-445 AND 50-446 1

1.0 INTRODUCTION

By application dated February 25,1998, (TXX-98050) as supplemented by letter dated March 9, 1998, (TXX-98066) for License Amendment Request (LAR)98-002; and subsequent applications dated March 12,1998, (TXX-98076) for LAR 98-003, and March 18,1998, (TXX-98079) for LAR 98-004, Texas Utilities Electric Company (TU Electric /the licensee) requested changes to the Technical Specifications (Appendix A to Facility Operating License Nos. NPF-87 and NPF-89) for the Comanche Peak Steam Electric Station (CPSES), Units 1 and 2.

This amendment is the result of three Notice of Enforcement Discretions (NOEDs) you requested and the NRC granted orally on February 20, March 10 and 13,1998. The NRC confirmed these NOEDs by letters dated February 24, March 13 and 17,1998, respectively. These NOEDs, although distinct actions, changed the same page of the CPSES TS, therefore, a single amendment is being issued to cover the three amendment requests. The three proposed changes are as follows:

The first would be a temporary change to the TSs to remove the requirement to demonstrate the load shedding feature of MCC XEB4-3 as par 1 of Surveillance Requirements (SRs) 4.8.1.1.2f.4)a) and 4.8.1.1.2f.6)a) until the plant startup subsequent to the next refueling outage for Unit or until an outage of 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> in duration.

The second would provide a temporary TS change for SRs 4.8.1.1.2f 4)b) and 4.8.1.1.2f.6)b) to allow the verification of the auto connected shut-down loads through the load sequencer to be performed at power for fuel cycle 6 on Unit 1 and fuel cycle 4 on Unit 2.

The third change would allow on a one-time basis, crediting performance of SRs 4.8.1.1.2f.4)a) and 4.8.1.1.2f.6)a), during POWER OPERATIONS as opposed to "during shutdown." Note that the bus tie breaker for MCC XEB4-3 for Unit 2 was not tested dering the last surveillance test and was the subject of change one of this amendment.

The supplemental information provided !n letter dated March 9,1998, was clarifying in nature and did not change the initial no significant hazards consideration determination.

9804240290 900420 PDR ADOCK 0500044S P

PDR

Mr. C. Lance Terry *

2.0 BACKGROUND

2.1 License Amendment Reauest 98-002 Backaround While performing a review of surveillance procedures in accordance with NRC Generic Letter 96-01, the licensee determined that the surveillance procedures for SRs 4.8.1.1.2f.4)a) and 4.8.1.1.2f.6)a) were deficient in that the load shedding of one electrical bus on Unit 2 had not previously been demonstrated. The surveillances required that upon a loss-of-offsite power, the emergency busses de-energize and load shedding occurs. The procedure for the train B diesel j

generator (DG) for Unit 2 did not require confirmation that bus XEB4-3 load sheds.

The licensee confirmed that failure to load shed this bus would not result in the DG being l

inoperable. The CPSES DGs have sufficient reserve capacity to emergency start and perform their safety functions with this bus loaded at time zero in the DG loading sequence. The licensee believed that this specification only required testing of the loads which are required to be load.

shed to allow the DG to perform its specified safety functions. Because the DG remains capable of performing its specified safety functions without the load shed of this bas, the licensee concluded that the surveillance had been met.

In subsequent discussions with the licensee, the NRC staff stated that CPSES was not in literal compliance with these SRs. Based on the feedback received from the NRC staff, the licensee declared the SRs as missed and invoked the requirements of TS 4.0.3 for a missed surveillance.

2.2 License Amendment Reauest 98-003 Backaround During the process of conducting reviews in accordance with NRC Generic Letter 96-01, CP3ES discovered that some of the Safety injection Sequencer (SIS) and Blackout Sequencer (BOS) block contacts had not been tested in accordance with SRs 4.8.1.1.2f.4)b) and 4.8.1.1.2f.6)b).

These surveillances were performed during the last refueling outage for each unit as part of the integrative tests. However, it was subsequently discovered that some of the sequencer loads had parallel starting paths such that it could not be determined, based only on the observation that the equipment had successfully started, that the specific contacts required to be tested had in fact operated. In addition, verification of testing of certain contacts was missing. Specifically, verification of testing of the sequencer load group contacts (BOS or SIS) to the following equipment is missing or cannot be distinguished from other possible circuit actuations:

BOS Contacts:

Safety Chill Water (SCW) Pump U1 both trains, U2 both trains Safety Chiller U1 both trains, U2 both trains Control Room Air Conditioner (CRAC) unit U1 both trains Battery Exhaust Fans 7,8,9,10 U1 both trains Battery Exhaust Fans 10,11 U1 both trains Instrument air compressors U2 both trains

Mr. C. Lance Terry SIS Contacts:

Safety Chill Water Pump U1 both trains, U2 both trains Safety Chiller U1 both trains, U2 both trains Control Room Air Conditioner (CRAC) Unit U1 both trains Emergency Fill Fire Pump U1 train A SR 4.8.1.1.2f requires, in part, that certain A.C. electrical sources be demonstrated OPERABLE by performing the SR at least once per 18 months, "during shutdown." Failure to perform the SR within the 18 month frequency plus allowances allowed per TS 4.0.2, would result in failure to perform a SR. In accordance with TS 4.0.3, this failure to perform the SR would constitute a noncompliance with the OPERABILITY requirements for the LCO. Also in accordance with TS 4.0.3, the ACTION requirements may be delayed for up to 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> to permit completion of the surveillance when the allowable outage time limits of the ACTION requirements are less than 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />.

With respect to SR 4.8.1.1.2f.4)b) and 4.8.1.1.2f.6)b), the licensee requested and the NRC -

granted enforcement discretion to not enforce compliance with the requirement to perform the surveillance "during shutdown", in order to demonstrate the OPERABILITY of the Si and BO Sequencer block contacts. On a one-time basis, crediting performance of those portions of SRs 4.8.1.1.2f.4)b) and 4.8.1.1.2f.6)b), during POWER OPERATIONS as opposed to "during shutdown"is seceptable.

2.3 License Amendment Reauest 98-004 Backaround During the process of conducting reviews in accordance with NRC Generic Letter 96-01, CPSES discovered that it had not positively verified that certain contacts from the undervoltage relays cause load shedding at the 480 voit MCCs. Therefore complete testing in accordance with SRs 4.8.1.1.2f.4)a) and 4.8.1.1.2f.6)a) has not been performed. A parallel circuit path containing a contact from the DG output breaker exists and could not bo conclusively eliminated as causing the observed load shed during performance of previous integrated tests.

SR 4.8.1.1.2f requires, in part, that certain A.C. electrica' sources be demonstrated OPERABLE by performing the SR at least once per 18 months, "during shutdown." Failure to perform the SR within the 18 month frequency plus allowances allowed per TS 4.0.2, would result in failure to perform a SR. In accordance with TS 4.0.3, this failure to perform the SR would constitute a noncompliance with the OPERABILITY requirements for the LCO. Also in accordance with TS 4.0.3, the ACTION requirements may be delayed for up to 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> to permit completion of the surveillance when the allowable outage time limits of the ACTION requirements are less than 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />.

With respect to SRs 4.8.1.1.2f.4)a) and 4.8.1.1.2f.6)a), the licensee requested and the NRC granted enforcement discretion to not enforce the requirement to perform the surveillance "during shutdown", in order to demonstrate the OPERABILITY by verifying load shedding occurs due to a loss-of-offsite power. On a one-time basis, crediting performance of SRs 4.8.1.1.2f.4)a) and 4.8.1.1.2f.6)a), during POWER OPERATIONS as opposed to "during shutdown" is acceptable.

Mr. C. Lance Terry

• 3.0 EVALUATION 3.1 License Amendment Reauest 98-002 Evaluation The licensee's supplemental information provided by letter dated March 9,1998, indicated that the Unit 1 bus had been tested. Therefore the original request which covered both Units was now only for Unit 2. Therefore, the initial no significant hazards consideration determination was not changed.

The safety function of the A.C. Sources is to ensure that sufficient power will be available to supply the safety related equipment required for: (1) the safe shutdown of the facility, and (2) the mitigation and control of accident conditions within the facility. The function of the SR of concem is to demonstrate that for a start of the DGs, the emergency busses will de-energize and sufficient load will be shed to allow the DG to start, connect to the emergency busses and load.

The maximum load that would be added by MCC XEB4-3 is 200Kw. The capacity of the CPSES DGs is 7000Kw. Since bus XEB4-3 could be loaded on the DG at any time in the loading sequence without affecting the ability of the DG to properly start, connect to the emergency bus and load, the DG's safety function is not adversely affected. Therefore, the NRC staff determined that based on the size of the loads on MCC XEB4-3 and the DG capacity a failure to load shed would not significantly impact the starting and loading of the DGs at CPSES, Unit 2.

3.2 License Amendment Reauest 98 003 Evaluation The safety function of the Si and BO Sequencer block contacts is to sequence necessary equipment loads onto an operating DG connected to the A.C. bus. These contacts are relied upon to ensure that the necessary equipment is loaded onto the bus at the appropriate time.

Failure of the affected equipment to properly load would place the operators in a situation where manual operator actions would be necessary to restore all attendant equipment to the A.C. bus.

The NRC staff determined that crediting the performance of SRs 4.8.1.1.2f.4)b) and 4.8.1.1.2f.8)b) for the Si and BO sequencer block contacts during power operations is acceptable because the SRs were satisfactorily completed during the previous refueling outage for the purpose of demonstrating the capability of the diesel generators to carry their required loads.

However, the operability of the Si and BO sequencer block contacts for certain loads were not verified. Therefore, it was not clear whether the Si and BO block contacts sequenced these loads on the diesel generators. The licensee has completed the portions of the SRs which have not been tested during the previous refueling outage. In addition, the staff believes that verification of this segment of the integrated test during power operation would pose no adverse effect to the A.C. electrical distribution system. Therefore, the staff finds that it is acceptable to credit the performance of the Si and BO Sequencer block contact testing at power for the current 18-month "during shutdown" SR for this one-time rather than requiring the coincident shutdown of both CPSES units after the tests were performed.

3.3 License Amendment Reauest 98-004 Evaluation i

The safety function of the undervoltage relays is to shed unnecessary equipment loads on the A.C. bus and allow an operating DG to be connected to the A.C. bus and power emergency i

equipment. These relays are relied upon to ensure that the necessary equipment is shed from

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Mr. C. Lance Terry

• the bus at the appropriate time. Failure of the affected equipment to properly shed loads would place the operators in a situation where manual operator actions would be necessary to remove the unnecessary equipment from the A.C. bus. These tests demonstrated that the contacts from the undervoltage relays closed upon actuation of the associated relay, thus completing the confirmation of the circuit by overlapping tests. Dunstream actuation of the relays and breaker trips was confirmed during the normal integrated surveillance test.

The NRC staff determined that allowing an additional 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> for the preparation and performance of portions of SRs 4.8.1.1.2f.4)a) and 4.8.1.1.2f.6)a)is acceptable. The NRC staff has also determined that crediting the performance of portions of SRs 4.8.1.1.2f.4)a) and 4.8.1.1.2f.6)a) during power operations is acceptable. These tests will demonstrate that the contacts from the undervoltage relays close upon actuation of the associated relay, thus completing the confirmation of the circuit by overlapping tests. Downstream actuation of the relays and breaker trips was confirmed during the normal integrated surveillance test (with the exception of the bus tie breaker for MCC XEB4-3 for Unit 2, which was addressed in a previous enforcement discretion and License Amendment Request (LAR) and is evaluated in Section 3.1 above). In addition, the staff believes that verification of these segments of the integrated tests during power operation would pose no adverse effect to the A.C. electrical distribution system.

Therefore, the staff finds that it is acceptable to credit the performance of the undervoltage relay contact testing at power for the current 18-month "during shutdown" SR for this one-time rather than requiring the coincident shutdown of both CPSES units after the tests were performed.

4.0 EXIGENT CIRCUMSTANCES

As described in Sections 2.1,2.2, and 2.3 above, each LAR was the result of reviewing surveillance procedures in accordance with NRC Generic 1.etter 96-01. In each case, the licensee took prompt action to remedy the situation, and entered TS 4.0.3 (which could have led to the shutdown of both CPSES Units 1 and 2 if the action requirements were not met within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />), evaluated the safety significance of the situation, and requested an NOED. Each LAR was submitted in a timely manner after the NOED was granted.

The Commission's regulations in 10 CFR 50.91 contain provisions for issuance of an amendment where the Commission finds that exigent circumstances exist, in that a licensee and the Commission must act quickly and that the time does not permit the Commission to publish a Feders/ Registernotice allowing 30 days for prior public comment. The exigency exists in this case in that the proposed amendment was the result of three NOEDs granted to prevent the shutdown of CPSES Units 1 and 2. Since these NOEDs changed the same page of the CPSES TS and occurred within a three week period, a single amendment is being issued to cover all three amendment requests. As a result, the first NOED has exceeded the 30-day comment period and is no longer considered exigent. The staff has determined that the licensee used its best efforts to make timely applications associated with the NOEDs.

Accordingly, the Commission has determined that exigent circumstances exist for two of the LARs (98-003 and 98-004) pursuant to 10 CFR 50.91(a)(6) and could not have been avoided, that the submittal of information was timely, and that the licensee did not create the exigent condition.

Mr. C. Lance Tony 6-

5.0 FINAL NO SIGNIFICANT HAZARDS CONSIDERATION

S DETERMINATION The Commission's regulations in 10 CFR 50.92(c) state that the Comr~.ission may make a final determination that a license amendment involves no significant hazaros consideration if operation of the facility in accordance with the proposed amendment would not (1) 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, or (3) result in a significant reduction in the margin of safety. The NRC staff has made a final determination that no significant hazards consideration is involved for the proposed amendment and that the amendment shot:Id be issued as allowed by the criteria contained in 10 CFR 50.91. The NRC staffs final determinations are presented below.

5.1 Final No Sionificant Hazards Considerations Determination for LAR 98-003

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

Crediting the at power performance of the portions of surveillance testing necesary to demonstrate the OPERABILITY of the Si and BO Sequencer block contacts, will not increase the probability or consequences of an accident previously evaluated. The conclusion has been reached that the probability of initiating a perturbation in the A.C. electrical distribution system is not created via the crediting of the tests. As the testing is conducted on only one train per unit at a given time, no increase in consequences, other than those previously postul6ted, are considered credible.

2. The change does not create the possibility of a new or different kind of accident from any accident previously evaluated.

Perturbations in the A.C. electrical distribution system have been fu"/ considered within the Final Safety Analysis Report. No new or different kind of perturbation or accident is deemed credible from crediting the performance of the testing.

3. The change does not involve a significant reduction in the margin of safety.

Crediting the required testing at power does not create any new failure scenarios or A.C.

electrical distribution perturbations, no associated margin is expected to be reduced. As such, there is no reduction in any mar @. cf eafety.

5.2 Final No Sionificant Hazards Considerations Determination for LAR 98-004

1. The change does not involve a significant increst4 in the probability or consequences of an accident previously evaluated.

Crediting the at power perfermance of the portims of surveillance testing necessary to demonstrate the OPERABILITY of the uridervoltage relays, will not increase the probability or consequences of an accident previously evel%iad. The conclusion has been reached that

a Mr. C. Lance Terry

-7 the probability of initiating an abnormal perturbation in the A.C. electricol distnbution system is not created via the crediting of the tests. As the testing was conducted on only one train per unit at a given time, no increase in consequences, other than those previously postulated, are considered credible.

2. The change does not create the pessibility of a new or different kind of accident from any accident previously evaluated.

Perturbations in the A.C. electrical distribution system have been fully considered within the Final Safety Analysis Report. No new or different kind of perturbation or accident is deemed credible from crediting the performance of the testing.

3. The change does not involve a significant reduction in the margin of safety.

Crediting the required testing at power does not create any new failure scenarios or abnormal A.C. electrical distribution perturbations. As such, there is no reduction in any margin of safety.

6.0 STATE CONSULTATION

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

7.0 ENVIRONMENTAL CONSIDERATION

The amendments change a requirement 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 ameridments involve no significant hazards consideration, and there has been no public comment on such finding (63 FR 11458), (63 FR 17238) and (63 FR 16287).

Ac?,ordingly, 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 environmental impact statement or environmental assessment need be prepared in connection with the issuance of the amendments.

8.0 CONCLUSION

The Commission has concluded, based on the considerations discussed above, that: (1) there is 4

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 the amendments will not be inimical to the common defense and security or to the health and safety of the public.

Principal Contributor: T. Polich Date: April 2C, 1998