ML20212J671

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Proposed Tech Specs,Permitting Operation for Up to 7 Days W/Diesel Generator 0 out-of-svc
ML20212J671
Person / Time
Site: LaSalle  Constellation icon.png
Issue date: 01/19/1987
From:
COMMONWEALTH EDISON CO.
To:
Shared Package
ML20212J664 List:
References
2530K, NUDOCS 8701280268
Download: ML20212J671 (8)
v • d • e


Text

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ATTACHMENT B PROPOSED CHANGES TO APPENDIX A OF THE TECHNICAL SPECIFICATIONS FOR OPERATING LICENSE NPF-11 AND NPF-18 REVISED PAGES:

NPF-11 NPF-18 3/4.8-1 3/4.8-la (New) 3/4.8-la (Replaced) 3/4.8-4 3/4.8-4 NOTE: A temporary revision to page 3/4.8-1 of NPF-11 which is similar to this request is currently pending. The temporary revision was transmitted to the NRC in Reference (d).

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A.C. SOURCES - OPERATING b fl. i?. Denlo,, clah.J to 'ft1/s c.

LIMITING CONDITION FOR OPERATION

3. 8.1.1 As a minimum, the following A.C. electrical power sources shall be OPERA 8LE:
a. Two physically independent circuits between the offsite transmission network and the onsite Class 1E distribution system, and
b. Separate and independent diesel generators #0, IA, 2A and 18 with: l
1. For diesel generator 0, IA and 2A:

l i a) A separate day fuel tank containing a minimum of 250 gallons of fuel.

b) A separate fuel storage system containing a minimum of .

31,000 gallons of fuel.

2. For diesel generator 18, a separate fuel storage tank / day tank containing a minimum of 29,750 gallons of fuel.
3. A separate fuel transfer pump.

APPLICABILITY: OPERATIONAL CONDITIONS 1, 2, and 3.

ACTION:

l a. With either one offs 1te circuit or diesel generator 0 or 1A of the above required A.C. electrical power sources inoperable, demonstrate the OPERASILITY of the remaining A.C. sources by performing Surveil-lance Requirements 4.8.1.1.la within 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br />, and 4.8.1.1.2a.4, I i for one diesel generator at a time, within eight hours, and at least l once per 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> thereafter; restore at least two offsite circuits and diesel generators 0 and 1A 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 be in at least HOT SHUTDOWN within the next 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> and in COLD SHUTDOWN within the following 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />.

b. With one offsite circuit and diesel generator 0 or 1A of the above required A.C. electrical power sources inoperable, demonstrate the OPERA 8ILITY of the remaining A.C. sources by performing Surveillance Requirements 4.8.1.1.la within 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br />, and 4.8.1.1.2a.4, for one l diesel generator at a time, within six hours, and at least once per 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> thereafter; restore at least one of the inoperable A.C.

sources to OPERABLE status within 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> or be in at least HOT SHUTDOWN within the next 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> and in COLD SHUTDOWN within the following 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />. Restore at least two offsite circuitss and diesel generators 0 and 1A to OPERA 8LE status within 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> from the time of initial loss or be in at least HOT SHUTDOWN within the next 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> and in COLD SHUTDOWN within the following 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />.

0. fee po3 e W r -1ct l LA SALLE - UNIT 1 3/4 8-1 Amendment No. 18

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  1. For the purposes of completing technical specification survyellance requirements 4.8.1.1.2d.1 and 4.8.1.1.2f.1, as part of a prd planned preventive maintenance program, on the O diesel generator the requirements of action statement a gg, modified tot
1. Eliminate the requirement for performing technical specification surveillance requirements 4.8.1.1.1a and 4.8.1.1.2a.4, on each operable AC source, immediately and once per 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> thereafter, when the O diesel generator is declared inoperable.
2. Allow an additional 96 hours0.00111 days <br />0.0267 hours <br />1.587302e-4 weeks <br />3.6528e-5 months <br /> in excess of the 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> allowed in action statement a for the 9 diesel generator to be inoperable.

Provided that the following conditions are met A. Unit 2 is in operational condition 4 or 5 or defueled prior to taking the O diesel generator out of service:

B. Surveillance requirements 4.8.1.1.la and 4.8.1.1.2a.4 are successfully completed, for the offsite power sources and the 1A and 2A diesel generators, within 48 hours5.555556e-4 days <br />0.0133 hours <br />7.936508e-5 weeks <br />1.8264e-5 months <br /> prior to removal of the O diesel generator from service.

C. No maintenance is performed on the offsite circuits or the 1A or 2A diesel generators, while the O diesel generator is inoperable.

D. Technical specification requirement 4.8.1.1.1a is performed daily, while the O diesel generator is inoperable.

E. The control circuit for the unit cross-tie circuit breakers between buses 142Y and 242Y are temporarily modified to allow the breakers to be closed with a diesel generator feeding the bus, while the O diesel generator is inoperable.

The provisions of technical specification 3.0.4 are not applicable.

LASALLE - Unit 1 3/4 8-la

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7s 0 a'A .7..B. m a 7 v . m...e n m a_ P a _ rj ELECTRICAL POWER SYSTEMS OLILY SURVEILLANCE REQUIREMENTS (Continued) i

d. At least once per 18 month b uring shutdown by:

l

1. Subjecting the diesel to an inspection in accordance with -

procedures prepared in conjunction with its manufacturer's recommendations for this class of standby service.

2. Verifying the diesel generator capability to reject a load of greater than or equal to 1190 kw for diesel generator 0, greater than or equal to 638 kw for diesel generators lA and 2A, and greater than or equal to 2381 kw for diesel generator 1B while maintaining engine speed less than or equal to 75% of the difference between nominal speed and the overspeed trip setpoint or 15% above nominal, whichever is less.
3. Verifying the diesel generator capability to reject a load of 2600 kw without tripping. The generator voltage shall not exceed 5000 volts during and following the load rejection.
4. Simulating a loss of offsite power by itself, and: .

a) For Divisions 1 and 2 and for Unit 2 Division 2:

1) Verifying de-energization of the emergency busses and load shedding from the emergency busses.
2) Verifying the diesel generator starts on the auto-start signal, energizes the emergency busses with permanently connected loads within 13 seconds, energizes the auto-connected loads and operates for greater than or equal to 5 minutes while its generator is so loaded. After energization, the steady state voltage and frequency of the emergency busses shall be maintained at 4160 1 150 volts and 60 1 1.2 Hz during this test.

b) For Division 3:

1) Verifying de-energization of the emergency bus.

l

2) Verifying the diesel generator starts on the auto-start -

l signal, energizes the emergency bus with its loads with-in 13 seconds and operates for greater than or equal to 5 minutes while its generator is so loaded. After energization, the steady state voltage and frequency of the emergency bus shall be maintained at 4160 1 150 volts and 60 1 1.2 Hz during this test.

l 5. Verifying that on an ECCS actuation test signal, without loss i of offsite power, diesel generators 0,1A and 18 start on the 1

auto-start signal and operate on standby for greater than or '

i equal to 5 minutes. The generator voltage and frequency shall be 1 4160 + 416, -150 volts and 60 + 3.0, -1.2 Hz within 13 seconds after the auto-start signal; the steady state generator voltage and frequency shall be maintained within these limits during this test.

"The specified 18 month interval may be waived for Cycle 1 provided the surveillance is performed during Refuel 1.

LASALLE-UNIT 1 3/4 8-4 Amendment No. 24 l

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' ELECTRICAL POWER SYSTEMS LIMITING CON 0! TION FOR OPERATION (Continued) y t*I*

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"For a 30 day period for each diesel generator 0 and 1A during the Unit 1 first refueling outage, with Unit 1 in operational condition 4 or 5 or defueled, only 3 diesel generators, 25 and 2A, and either 0 or 1A are required to satisfy the j staney AC ensite power requirements for Unit 2. Surveillance requirements, f 4.8.1.1.3a and 4.8.1.1.2a.4 shall be performed within 48 heves prior to removal of the 0 or IA diesel generator from service. During each 30 day period the remaining 3 diesel generators will be verified 1 operable at least once per day (in addition to any testing required by Table 4.8.1.1.2-1). The control cir-cuit for the unit cross-tie circuit breakars between buses 142Y and 242Y shall be temporarily modified to allow the breakers to be closed with the diesel

{ generator feeding the bus. In the event these conditions are not est Unit 2 will be brought to NOT $NUTDOW within 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> and COLD SHUTDOWN within the following 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />. The previsions of Technical specification 3.0.4 de not apply.

1The term verify as used in this context means to administrative 1y check by examining logs or other information to determine if certain components are

- out-of-service for maintenance or other reasons. It does not mean to perform the surveillance requirements needed to demonstrate the OPERASILITY of the components.

LASALLE - UNIT 2' 3/4 8-la Amenhnt No.16 e

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NEW PAGE

  • For the purposes of completing technical specification survie11ance requirements 4.8.1.1.2d.1 and 4.8.1.1.2f.1, as part of a pre planned preventive maintenance program, on the O diesel generator the requirements ofactionstatementsago,modifiedtot
1. Eliminate the requirement for performing technical specification surveillance requirements 4.8.1.1.la and 4.8.1.1.2a.4, on each operable AC source, immediately and once per 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> thereafter, when the O diesel generator is declared inoperable.

i 2.

Allow an additional 96 hours0.00111 days <br />0.0267 hours <br />1.587302e-4 weeks <br />3.6528e-5 months <br /> in excess of the 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> allowed in action statement a for the O diesel generator to be inoperable.

provided that the following conditions are met:

A. Unit 1 is in operational condition 4 or 5 or defueled prior to j taking the O diesel generator out of service.

B. Surveillance requirements 4.8.1.1.la and 4.8.1.1.2a.4 are successfully completed, for the offsite power sources and the 1A or 2A diesel generators, within 48 hours5.555556e-4 days <br />0.0133 hours <br />7.936508e-5 weeks <br />1.8264e-5 months <br /> prior to removal of the O diesel generator from service.

1 C. No maintenance is performed on the offsite circuits or the 1A or 2A diesel generators, while the O diesel generator is inoperable.

D.

Technical specification requirement 4.8.1.1.la is performed daily, while the O diesel generator is inoperable.

E. The control circuit for the unit cross-tie circuit breakers between buses 142Y and 242Y are temporarily modified to allow the breakers to be closed with a diesel generator feeding the bus, while the O diesel generator is inoperable.

The provisions of technical specification 3.0.4 are not applicable.

-LASALLE - Unit 2 3/4 8-la

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e.m 2 ELECTRICAL POWER SYSTEMS SURVEILLANCE REQUIREMENTS (Continued) F

. d. At least once per 18 month uring shutdown by: 'f

1. Subjecting the diesel to an inspection in accordance with -

procedures prepared in conjunction with its manufacturer's recommendations for this class of standby service.

2. Verifying the diesel generator capability to reject a load of greater than or equal to 1190 kW for diesel generator 0, greater than or equal to 638 kW for diesel generators 1A and 2A, and greater than or equal to 2381 kW for diesel generator 2B while maintaining engine speed less than or equal to 75% of the i

difference between nominal speed and the overspeed trip setpoint or 15% above nominal, whichever is less.

3. Verifying the diesel generator capability to reject a load of 2600 kW without tripping. The generator voltage shall not exceed 5000 volts during and following the load rejection.
4. Simulating a loss-of-offsite power by itself, and:

a) For Divisions 1 and 2 and for Unit 1 Division 2:

1) Verifying deerzergization of the emergency busses and load shedding from the emergency busses. >
2) Verifying the diesel generator starts on the auto-start

. signal, energizes the emergency busses with permanently 1

connected loads within 13 seconds, energizes the auto-connected loads and operates for greater than or equal to 5 minutes while its generator is so loaded. After energization, the steady-state voltage artd frequency i

of the emergency busses shall be maintained at 4160 t i 150 volts and 60 2 1.2 Hz during this test.

b) For Division 3:

1) Verifying deenergization of the emergency bus.
2) Verifying the diesel generator starts on the auto-start
signal, energizes the emergency bus with its loads with-i in 13 seconds and operates for greater than or equal to 5 minutes while its generator is so loaded. After energization, the steady-state voltage and frequency of the emergency bus shall be maintained at 4160 t 150 volts and 60 2 1.2 Hz during this test.
  • l . 5.
  • Verifying that on an ECCS actuation test signal, without loss-of-offsite power, diesel generators 0, 2A, and 28 start on the auto-start signal and operate on standby for greater than or equal to 5 minutes. The generator voltage and frequency shall be i

4160 + 416, -150 volts and 60 + 3.0, -1.2 Hz within 13 seconds

, . after the auto-start signal; the steady.-state generator voltage and j frequency shall be maintained within these limits during this test.

"The specified 18 month interval may be waived for Unit 1, Cycle 1, provided

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j the surveillance is performed during Unit 1, Refu'l e 1.

i LA SALLE - UNIT 2 3/4 8-4 Amendment No.13 I.. ~.---..._9--,___, . . . _ _ . . _ - . , - - __m.,__ - . _ . - . - , - - . ._. . - . _ - _ ._

.=e ATTACHENT C Significant Hazards Consideration Commonwealth Edison has evaluated the proposed Technical Specification ATsuT at and determined that it does not represent a significant hazards consiceration. Based on the criteria for defining a significant hazards consideration established in 10 CFR 50.92, operation of LaSalle County Station Units 1 anc 2 in accordance with the proposec amendment will not:

1) Involve a significant increase in the probability or consequences of an accident previously evaluated because in the event of a loss of offsite power with the "0" oe *** diesel inoperable for this period sufficient onsite power with a single active failure will still be available to safely shutdown'.
2) Create the possibility of a new or different kind of accident from .

any accident previously evaluated because emergency power is still available to those systems recuired to mitigate accidents evaluated in the FSAR.

3) Involve a significant reduction in the margin of safety because the probability of a loss of offsite power in addition to a remaining diesel generator failure during the period of tnese diesel generator modifications is sufficiently small to reasonably assure the health and safety of the public.

Based on the preceding discussion, it is concluded that the proposed system change clearly falls within all acceptable criteria with respect to the system or component, the consequences of previously evaluated accidents will not be increased and the margin of safety will rot ce decreased. Therefore, based on the guidance provided in the Federal Register and the criteria established in 10CFR50.92(e), the proposed change does not constitute a significant hazards consideration.

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. # o., UNITED STATES NOV 13 g

[ g NUCLEAR REGULATORY COMMISSION t a wasumarom, o. c. 20ssa -

'+, .o' O eaw 35 Docket No. 50-374 Mr. Dennis L. Farrar Director of Licensing Ccriconwealth Edison Company P.O. Box 767 Chicago, Illinois 60690

Dear Mr. Farrar:

SUBJECT:

ISSUANCE OF AMENDMENT NC.16 TO FACILITY OPERATING LICENSE N0. NPF LA SALLE COUNTY STATION, UNIT 2 The Nuclear Regulatory Comission has issued the enclosed Amendment No.16 to Facility Operating License No. NPF-18 for the La Salle County Station, Unit 2.

This amendment is in response to your request by letter dated August 28, 1985.

The amendment provides relief, during the La Salle Unit i refueling outage, by extending the present three-day or seven-day period to thirty days during which-only three diesel generators would be required to satisfy the standby AC on-site-power requirements for Unit 2. This request was made so that you could perform the modification required by Unit 1 License Condition 2.C.30(1)(b) on the shared diesel generators without having to shut down both Units.

A copy of the related safety evaluation supporting Amendment No.16 to Facility Operating License NPF-18 is enclosed.

1 Sincerely, Walter R. Butler, Chief Licensing Branch No. 2 Division of Licensing

Enclosures:

1. Amendment No.16 to NPF-18
2. Safety Evaluation cc w/ enclosure:

See next page l

l l

l -Fkl4LM99-p.

Mr. Dennis L. Farrar La Salle County fluclear Power Station Comonwealth Edison Company Units 1 & 2 cc:

Philip P..Steptce, Esquire John W. McCaffrey ~

Suite 4200 Chief, Public Utilities Division One First National .'la::a 160 North La Salle Street, Room 900 Chicago, Illinois 60603 Chicago, Illinois 60601 Assistant Attorney General 188 West Randolph Street Suite 2315 Chicago, Illinois 60601 Resident Inspector /LaSalle, NPS U.S. Nuclear Regulatory Comission Rural Route No. 1 Post Office Box 224 Marseilles Illinois 61341 Chairman La Salle County Board of Supervisors La Salle County Courthouse Ottawa, Illinois 61350 Attorney General 500 South 2nd Street Springfield, Illinois 62701 Chainnan Illinois Comerce Comission Leland Building 527 East Capitol Avenue Springfield, Illinois 62706 Mr. Gary N. Wright, Manager i

Nuclear Facility Safety Illinois Department of Nuclear Safety 1035 Outer Park Drive 5th Floor Springfield, Illinois 62704 Regional Administrator, Region III U. S. Nuclear Regulatory Comission 799 Rossevelt Road j Glen Ellyn, Illinois 60137 l

l l

- .__ - . . _ _ . _ _ . - - _ , _ _ - _ . ~ . . . _ - _ _ . . _ _ _ - . _ . . _ _ . . , _ . _ _ . . _ _ _ _ _ _ . , _ - . _ - . . _ . _ _ _ . . -, - . _ _

/  %,, UNITED STATES

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COMMONWEALTH EDISON COMPANY DOCKET NO. 50-374 LA SALLE COUNTY STATION, UNIT 2 AMENDMENT TO FACILITY OPERATING LICENSE Amendment No. 16 License No. NPF-18

1. The Nuclear Regulatory Comission (the Ccmission or the NRC) having found that:

A. The application for amendment filed by the Ccmonwealth Edison Company, dated August 28, 1985, complies with the standards and requirements of the Atomic Energy Act of 1954, as amended (the Act), and the Comission's regulations set forth in 10.CFR Chapter I; B. The facility will operate in conformity with the application, the provisions of the Act, and the regulations of the Comission; C. There is reasonable assurance: (1) that the activities authorized by this amendment can be conducted without endangering the health and safety of the public, and (ii) that such activities will be conducted in compliance with the Comission's regulations set forth in 10 CFR Chapter I; D. The issuance of this amendment will not be inimical to the ccmon defense and security or to the health and safety of the public; and E. The issuance of this amendment is in accordance with 10 CFR Part 51 of the Comission's regulations and all applicable requirements have -

been satisfied.

2. Accordingly, the license is amended by changes to the Technical Specifications as indicated in the attachment to this license amendment and paragraph 2.C.(2) of Facility Operating License No. NPF-18 is hereby amended to read as follows:

(2) Technical Specifications and Environmental Protection Plan The Technical Specifications contained in Appendix A, as revised through Amendment No.16 and the Environmental Protection Plan contained in Appendix B, are hereby incorporated in the license.

The licensee shall operate the facility in accordance with the

Technical Specifications and the Environmental Protection Plan.

I P

l WP

3. This amendment is effective as of the date Unit 1 initiates its first refueling outage. _

FOR THE NUCLEAR REGULATORY COMMISSION 6

Walter R. Butler, Chief Licensing Branch No. 2 Division of Licensing

Enclosure:

4 Changes to the Technical Specifications Date of Issuance: MOV 13 M l

ENCLOSURE TO LICENSE AMEN 0 MENT NO.16 FACILITY OPERATING LICENSE NO. NPF-18 00CKET NO. 50-374 Replace the following pages of the Appendix "A" Technical Specifications with the enclosed pages. The revised pages are identified by Amendment number and .

contain a vertical line indicating the area of change.

REMOVE INSERT 3/4 8-1 3/4 8-1 3/4 8-la i

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l 3/4.8 ELECTRICAL POWER SYSTEMS 3/4.8.1 A.C. SOURCES A.C. SOURCES - OPERATING l t

LIMITING CONDITION FOR OPERATION

3. 8.1.1 As a minimum, the following A.C. electrical power sources shall be OPERA 8LE:
a. Two physically independent circuits between the offsite transmission network and the onsite Class 1E distribution system, and
b. Separate and independent diesel generators
  • 0, IA, 2A and 2B with: [
1. For diesel generator 0, IA and 2A

i a) A separate day fuel tank containing a minimum of 250 gallons of fuel.

b) A separate fuel storage system containing a minimum of 31,000 gallons of fuel.

2. For diesel generator 28, a separate fuel storage tank / day tank containing a minimum of 29,750 gallons of fuel.

, 3. A separate fuel transfer pump.

APPLICA8ILITY: OPERATIONAL CONDITIONS 1, 2, and 3.

ACTION:

a. With either one offsite circuit or diesel generator 0 or 2A of the above required A.C. electrical power sources inoperable, demonstrate the OPERA 8ILITY of the remaining A.C. sources by performing Surveil-lance Requirements 4.8.1.1.la. within 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br />, and 4.8.1.1.2a.4.,

for one diesel generator at a time, within 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br />, and at least once per 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> thereafter; restore at least two offsite circuits and diesel generators 0 and 2A to OPERA 8LE status within 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> or

, be in at least HOT ~ SHUTDOWN within the next 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> and in CCLD SHUTDOWN within the following 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />.

b. With one offsite circuit and diesel generator 0 or 2A of the above required A.C. electrical power sources inoperable, demonstrate the OPERA 8ILITY of the remaining A.C. sources by performing Surveillance Requirements 4.8.1.1.la. within 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br />, and 4.8.1.1.2a.4., for one diesel generator at a time, within 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br />, and at least once per 8 hcurs thereafter; restore at least one of the inoperable A.C.

sources to OPERA 8LE status within 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> or be in at least HOT SHUTDOWN within the next 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> and in COLD SHUTDOWN within the following 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />. Restore at least two offsite circuits and diesel generators 0 and 2A to OPERA 8LE status within 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> from the time of initial loss or be in at least HOT SHUTDOWN within the

next 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> and in COLD SHUTDOWN within the following 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />.
  • See page 3/4 8-1(a). .

i l

4 LASALLE - UNIT.2 3/4 8-1 Amendment No.16

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  • ELECTRICAL POWER SYSTEMS LIMITING CONDITION FOR OPERATION (Continued) l a

"For a 30 day period for each diesel generator 0 and 1A during the Unit 1 first .

refueling outage, with Unit 1 in operational condition 4 or 5 or defueled, only 3 diesel generators, 28 and 2A, and either 0 or 1A are required to satisfy the standby AC onsite power requirements for Unit 2. Surveillance requirements, 4.8.1.1.la and 4.8.1.1.2a.4 shall be performed within 48 hours5.555556e-4 days <br />0.0133 hours <br />7.936508e-5 weeks <br />1.8264e-5 months <br /> prior to removal of the 0 or 1A diesel generator from service. During each 30 day period the remaining 3 diesel generators will be verified 1 operable at least once per day l (in addition to any testing required by Table 4.8.1.1.2-1). The control cir-cuit for the unit cross-tie circuit breakers between buses 142Y and 242Y shall be temporarily modified to allow the breakers to be closed with the diesel generator feeding the bus. In the event these conditions are not met, Unit 2 i

will be brought to HOT SHUTDOWN within 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> and COLD SHUTDOWN within the following 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />. The provisions of Technical Specification 3.0.4 do not

apply.

l l 1The term verify as used in this context means to administrative 1y check by

examining logs or other information to determine if certain components are

, out-of-service for maintenance or other reasons. It does not mean to perform l the surveillance requirements needed to demonstrate the OPERA 8ILITY of the

, components.

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l LASALLE - UNIT 2 3/4 8-la Amendment. No. 16 l

I

  1. o UNITED STATE 3

" g I o NUCLEAR REGULATORY COMMISSION l . .$ I wasMNGTON. O. C. 20085

%*..../

SAFETY EVALUATICN AMENDMENT NO.16 TO NPF-18 LA SALLE COUNTY STATION, UNIT 2 DOCKET NO. 50-374 Introduction By letter dated August 28, 1985, Comonwealth Edison Company (the licensee)

requested a one-time technical relief, during the present, first refueling outage for La Salle Unit 1, to allow the two diesel generators required by

~

La Salle Units 1 and 2 Technical Specifications, 0 and 1A, be inoperable for a 30 day period without perfonnirg surveillance of the other operable diesel -

generators every 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> as required by the Technical Specifications. This one time change will allow the installation of the diesel generator lube oil modification required by the La Salle Unit 1 License Condition 2.C.(2)(1)(b)

to be installed on Unit 1 prior to startup after the first refueling outage.

Because of the fact that Diesel Generator 0 is shared between La Salle Units 1 and 2 and Diesel Generator 1A of Unit 1 is designed to supply power to the Unit 2 equipment (e.gt standby gas treatment, hydrogen recombiner, and emergency filtration for the control room) the present Technical Specifications for Unit 2 require that Diesel Generators 0, IA, 2A, and 2B be operable. Otherwise, if one of the three diesel generators (0, 2A; or 28) is inoperable, the action

, statement permits 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> of reactor operation before action must be taken to shut down the unit. For Diesel Generator 1A, the action statement allows a mar.imum of 10 days of reactor operation before action must be taken to shut down the unit. Furthennore, each action requires the other operable diesel generators to be tested every 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> during this interval of inoperable diesel generator. Thus, the proposed relief from the requirements of the -

i Technical Specifications would extend the present three-day limiting condition l for operation to a duration of 30 days for Diesel Generator 0 modification, while for Diesel Generator 1A from 10 days to 30 days.

j The licensee proposes to modify the Diesel Generators 0,1A, and 18 during l the upccming Unit I refueling outage while the changes for the remaining diesel generators (2A and 28) will be completed during the Unit 2 refueling outage.

Furthennore, the licensee states that no maintenance is to be perfonned on the

. other diesel generators required for unit operation while a diesel generator is

[ being modified.

l l EVALUATION The Coninenwealth Edison Company is currently a member of the Mid-America Interpool Network for the purpose of ensuring that the transmission system is reliable and adequate. La Salle County Station is interconnected to the above electrical grid system through four 345 kV overhead transmission lines which enter the station by way of two separate rights-of-way. These four 345kV S5i.Idh

~ . . .

-QO-

i circuits in the switchyard are connected to ten circuit breakers in a ring-bus arrangement. This ring bus configuration provides for quickly locating and

isolating any system fault or equipment failure. Therefore, any single failure ~

1 would only affect one source of offsite power. The staff has reviewed the data base for loss of offsite power (LOOP) events compiled in NUREG/CR-3992, " Loss of

, Off-site Power at U.S. Nuclear Plants," and found that La Salle County Station has not experienced a LOOP event since its initial criticality in 1982.

i The primary supply (an immediate access circuit) to the three onsite Engineered Safety Feature (ESF) buses for Unit 2 is provided by a 345/4.16 kV system auxiliary transformer (SAT), SAT-242. The alternate supply (delayed access circuit) is manually connected to the onsite system (only two of the three ESF buses) from the Unit 1 ESF buses through the unit auxiliary transfonners (UAT), UAT-141, or the system auxiliary transformer (SAT-142).

The onsite power system is designed such that five diesel generators (0, IA, 1B for Unit 1 and 2A, 28 for Unit 2) are used to provide onsite power to six Class 1E ESF buses (three for each unit). Among the five diesel generators, j

Diesel Generators IA and 2A are assigned to Division 2 Diesel Generators i 18 and 28 to Division 3, and Diesel Generator 0 is shared between Division 1 I of two units. With Unit 1 in cold shutdown, only three of the four diesel

, generators (0, IA, 2A, and 28) are required to satisfy the standby AC onsite i power requirement for Unit 2; however, the Technical Specifications require ,

fcur functional diesel generators.

As for the onsite power sources, the licensee states that La Salle's diesel

! generator reliability exceeds 0.99 while the U.S. average diesel generator reliability is 0.98, according to NUREG-1032, " Evaluation of Station Blackout Accidents at Nuclear Power Plants," Table 1.1, "Sununary of Station Blackout Program Technical Results." Further, the licensee states that the station record indicates only seven failures in over 600 diesel generator starts.

Within the last three years, only one failure has occurred. Thus, La Salle presently maintains a 30 day test interval for their diesel generators, as required by the Technical Specifications because of this failure rate. The .

staff has reviewed the licensee's probability assessment that a LOOP occurs concurrently with one or two aiesel generators failures during a 30 day period

, as requested by the licensee. We concur with the licensee's finding that the

probability of such an event during that period is sufficiently small. In addition, we corroborated the licensee's conclusion by performing our own assessment and arrived at the same conclusion (see Attachment). Also, the licensee has perfonned a loop transient analysis with any combination of diesel generators being inoperable and they have detennined that the unit can be shut-
down with one operable ESF division.

! Aside from the required monthly diesel generator surveillances, the licensee

! will perfonn the following additional tests:

1. The diesel generators needed for the operation will be demonstrated to 4

be operable by performing the surveillance test required by Specification l 4.8.1.1.2a.4 prior to taking the other ciesel generator out-of-service.

l' In addition, the licensee, by letter dated October 2,1985 has consnitted to perfonn the above surveillance test (Specification 4.8.1.1.2a.4) again at the 14th day of the 30-day period. If any diesel generator fails to ,

t

start properly, the appropriate action called for in the Technical Speciff-cations would be taken.

2. The control circuit for the unit cross-tie breakers between Diesel -

Generators IA and 2A will be temporarily modified to allow the unit tie breakers to be manually closed (from the control room) if such a need arises.

Based on: (1) the favorable operating history of the offsite power system and the diesel generators, (2) the number of available paths to the onsite buses from the offsite sources, (3) the prcbability assessment, and (4) power the fact that one ESF division can safely shutdown the unit for LOOP, the LOOP does not represent a significant threat to the health and safety of the public for the period proposed. For the accident situation, it is our judgement that a large break loss-of-coolant accident concurrent with a LOOP and the loss of an additional diesel generator is a very unlikely event over the 30 day period for

. Diesel Generators 0 and 1A outages; and, therefore, does not represent a signif-icant danger to the health and safety of the public. We will reouest that the NRC Resident InsDector, before any action is taken by the licensee, is assured

v. hat adeouate DroCecures have been develoDeo for Ine sneccing or nonessential oads from 01esel Generator IA and the operation of Ene t1e breakers between 142Y and 242Y buses are in slace. The staff, therefore, concludes tnat tne proposeo one time re ief from t1e requireinents of the Technical Specifications is acceptable.

ENVIRONNENTAL CONSIDERATION This amendment changes requirements with respect to use of a facility component located within the restricted area as defined in 10 CFR Part 20 and changes surveillance requirements. We have determined that the amendment involves no significant increase in the amcunts, 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 cccupational radiation exposure. The Commission has previously issued a proposed finding that this amendment involves no significant hazards consideration and the only comments received have been addressed in the safety evaluation. Accordingly, this amendment meets the eligibility criteria for categorical exclusion set forth in 10 CFR 51.22(c)(9).

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

CONCLUSION We have 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, and (2) such activities will be conducted in compliance with the Coninission's regulations and the issuance of this amendment will not be inimical to the coninon defense and security or to the health and safety of the public.

Dated: NOV 13 S

- - . - - - . - ,-. -_ -....,,.,,-.m..____.,--__,.__m.,________,.__,_

l ATTACHMENT The staff has conservatively estimated the probability for severe core damage for La Salle Unit 2 fr of an order of 3 X 10'gm this . Thisone-time probability change wasinarrived Technical Specifications at by the following.to be Two cases must be considered: either Diesel Generator 0 is taken out of service for the lube oil modification, or Diesel Generator IA is taken out of service. Of these two cases, the worst case is that where Diesel Generator 0 is taken out of service; Diesel Generator 0 is the swing diesel. The con-servative estimate of severe core damage probability was obtained by assuming that if (1) a loss of offsite power of duration greater than 1/2 hour were to take place during the 30 day period, with Diesel Generator 0 out of service, (2) Diesel Generator 2A fails to start, and (3) there is failure to power bus 242Y (normally pcvered by Diesel Generator 2A) by Diesel Generator IA; then severe core damage occurs. In actuality, if the Reactor Core Isolation Cooling System or the High Pressure Core Spray System were operable, severe core damage would not occur for scme hours, during which time either offsite or onsite power might be recovered. The amount of time before severe core damage would occur has not been investigated.

The estimate of severe core damage probability associated with the proposed change to the Technical Specifications used the following data:

(1) Loss of offsite power frequency for periods greater than 1/2 hour .03/ year (from NUREG-1032 " Evaluation of Station Blackout Program Technical Results " Figure A.10. This figure gives the frequency of losses of offsite power exceeding specified durations i for Zion (another Comonwealth Edison nuclear station). It was assumed that Zion and La Salle have similar loss of offsite power frequency versus duration curves).

(2) Probability Diesel Generator 2A fails to start .01/ day (plant specific data given by the licensee in its August 28, 1985 letter).

(3) Fraction of Diesel Generator 1A or Diesel Generator 0 is inoperable for the lube oil mootfication - 30/365 (we are assuming in actuality the Ofesel Generator 0 is out for thirty days since that is the worstcase).

(4) Probability of failure to power bus 242Y (normally powered by Diesel Generator 1A) - 0.1 (This estimate of the probability of failure to power bus 242Y by Diesel Generator 1A is a conservative estimate which includes the conditional probability of failure of Diesel

, Generator 1A, given Diesel Generator 2A fails to start; and the probability of human error of failing to properly close the tie breakers between buses 142Y and 247.Y, or improperly shedding the nonessential loads on Diesel Generator 1A. Since the tie breakers between buses 142Y and 242Y can be closed from the control room, this is a conservative estimate.)

{

N

The preguet of these four quantities yields our conservative estimate of 3 X 10 of probability for a severe core damage at La Salle Unit 2 due to the one-time change in the Technical Specifications. Since the increase in core melt probability from this one-time change in Technical Specifications _

is estimated to be small, even en a conservative basis, and since the diesel generator lube oil modification to be made will likely improve the long term I reliability of the diesel generators, we find the proposed change to be acceptable.

a 4

NM *M

. Commonwealth Edison One First Natonal Plaza. Chicago Illinos Address Reply to: Post Offce Box 767 Chicago. Illinos 60690 0767 October 14, 1906 Mr. Harold R. Denton, Director office of Nuclear Reactor hegulation U.S. Nuclear Regulatory Commission Washington, DC 20555

Subject:

LaSalle County station Unit 1 Proposed Amendments to Technical Specification for Facility Operating License NPF-ll - Diesel Generator Lube oil Modification submittal NRC Docket No. 50-373 References (a): License Condition NPF-18 2.(C).12.(b).

(b): March 12, 1984, letter from J. Norris (NRR) to D. L. Farrar regarding Similar Amendments to the ,

Zion Technical Spectification.

(c): Draft NUREG-1032 on Station Blackouts.

(d): UFSAR Figures 8.1-1 and 8.1-2.

(e): W. Butler letter to D. L. Farrar dated November 13, 1985.

Dear Mr. Denton:

Pursuant to 10 CFR 50.90, Commonwealth Edison proposes to amend Appendix A. Technical Specification, to Facility Operating License NPF-ll.

These amendment changes are being submitted for your staff's review and approval to permit continued Unit 1 operation during the installation of a modification to the lube oil system of the 2A Diesel Generator. This modification is required to satisfy one of the License Conditions contained in License NPF-18 (Reference (a)).

.} & )h- )

W-

i H. R. Denton October 14, 1986 0 -

Attachment A provides background and discussion. The proposed revised change is enclosed in Attachment B. The attached change has received both on-site and off-Site review and approval. We have reviewed this amendment request and find that no significant hazards consideration

! exists. Our review is documented in Attachment C. Attachment D is the station blackout assessment and Attachment E is a loss of off-site power

, transient analysis, i

j commonwealth Edison is notifying the State of Illinois of our

{ request for this amendment by transmitting a copy of this letter and attachments to the designated State official.

These one-time changes will allow installation of the diesel generator lube oil modification by extending the present ten-day period to thirty days during which, with Unit 2 in Cold Shutdown, Refuel Mode, or i defueled, only three diesel generators would be required to satisfy the

standby AC on-site power requirement for Unit 1.

During the Unit 1 first refuel outage, Ceco modified the 0, 1A and

l 1B diesels. During the Unit 2 first refuel outage, Ceco will modify the 2A l and 28 diesels. This satisfies the license conditions for the respective j units. The Unit 2 refuel outage is expected to begin in January,1987.

The requested extension on the out-of-service time for the "2A" diesel generator is required to prevent the shutdown of Unit I within a

maximum of 10 days ("2A" diesel generator T.S. 3.8.1.1 action f, with standby l gas treatment being declared inoperable after 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />). This shutdown would be required to be maintained for the duration of the modification.

l Please note that your approval of this change is required prior to

l. the installation of these modifications. Commonwealth Edison requests that i you consider this be a high priority item, to be concluded at the earliest l

possible date. This change is similar to'that already reviewed and approved by Amendment 16 to License NPF-18.

l l

! Please direct any questions you may have concerning this matter to this office. In accordance with the provisions of 10 CFR 50.30, three (3) i signed and affirmed originals and forty (40) copies of this letter and attachments are enclosed.

1 l .

i

H. R. Denton october 14, 1986 A fee remittance in the amount of $150.00 is enclosed in compliance with 10 CFR 170.

[ry truly yours, J

C. M. Allen Nuclear Licensing Administrator im Attachments cc: Dr. A. Bournia Resident Inspector - LSCS M. C. Parker - IDNS SUBSCRIBED AND SWpR to l, is / "f ' day beforp'/J of /

6, 41' , 1986

)h V ' Notary Public

. b' blisi i

l 2250K l

ATTACHMENT A TECHNICAL SPECIFICATION CHANGE REOUEST MSALLE COUNTY STATION UNIT 1

SUBJECT:

LaSalle County Station Unit 1 Diesel Generator Lube Oil Modification Temporary Change to the Technical Specifications BACKGROUND AND DISCUCION:

This proposal revises section 3.8.1.1. of the Technical Specifica-tions to allow one of the three ESF bivision 1 or 2 diesel generators (0, lA, and 2A) to be inoperable for a 30 day period without requiring both units to be in cold shutdown and without requiring the other operable diesels to be tested every 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br />. With this change the station will be able to install the EMD M.I. 9644 lube oil modification on diesel 2A without suffering a large economic loss. This modification is required by reference (a).

Entensive changes to the lube oil system are requirad for this modification. A 3 gpm pump, two oil pressure alarm switches, and new lines must be added to the system, and several existing lines modified. Upon completion of the installation, the Architect Engineer must perform a seismic analysis of the piping and the station must perform numerious tests such as hydrostatic tests on the piping, detailed and functional tests of

.the lube oil system with the diesel shutdown and running, and start and load tests on the diesel generator. Recent modifications to the "O" and "1A" l diesel generators took a large portion of the 30 days allowed.

We have concluded that the proposed change will not endanger the health and safety of the public provided the following conditions are met before a diesel is taken out of service for modification and while the I diesel is being modified:

i

1. Unit 2 must be in Cold shutdown, Refuel Mode or defueled before DG-2A is declared inoperable.

l

2. Both system auxiliary transformers are operable.

l l 3. No maintenance is to be performed on the other diesels required for unit operation while the diesel is being modified.

4. The other diesels needed for unit operation shall be demonstrated to be operable immediately prior (within 48 hours5.555556e-4 days <br />0.0133 hours <br />7.936508e-5 weeks <br />1.8264e-5 months <br />) to taking the diesel out of service and shall be verified to be operable at least

( once a day during the 30 day period. Please note that verify does not specifically mean to test.

l l

l i . , _ -_ _ __ , , , , , _ _ _ _ _ _ - _ _

5. The 0, 1B, and 1A diesel generators will be started during the 30 day period at approximately the 14th day of the period. If a diesel fails to properly start, the appropriate Technical Specification actions would be taken.
6. Immediately prior to and during the diesel outage, the control circuit for the unit cross-tie circuit breakers between 4kV buses 142Y and 242Y shall be temporarily modified to remove the.

interlocks with the DG output and main feed breakers. This change will allow that unit tie breakers to be manually closed while the DG is feeding the bus.

The first condition minimizes the exposure period with one diesel inoperable and the consequences of a Loss of Off-site Power (LOSP) transient.

The next three conditions reduce the probability that an ESF bus will be without power, and the last condition ensures that power will be available to at least one of the ESF Division 2 buses following a LOSP event.

The proposed Technical Specification changes are justifiable for the following reasons:

1. The probability that a station blackout will occur during the 30 days is extremely unlikely.
2. The operating unit can be safely shutdown following a LOSP transient even if one of the remaining diesels fail.

The chances that a station blackout will occur is negligible due to the high reliability of the commonwealth Edison Company transmission network,'the LaSalle switchyard, and its diesel generators. Based on operational experience, the reliability of these systems is considerably higher than the industry average. The average nuclear power plant experiences about one LOSP event every ten years (reference (c)). Part of the reason for our high relial?.lity is that the switchyard is designed so that a single failure can not cause a LOSP. It is connected to four 345 KV transmission lines and is arranged in a ring-bus configuration with ten circuit breakers (reference (d)). Thus, any system fault or equipment failure is quickly located and isolated.

-_- We have reviewed the auxiliary power bus fast transfer schemes as utilized at LaSalle and have concluded that the design feature which caused a bus transfer failure at Dresden Unit 2 on August 16, 1985 does not exist at LaSalle

n The LaSalle diesels also have a higher than average reliability.

The average emergency diesel generator has a reliability of 0.98 (reference (c)), and those at LaSalle have a reliability that exceeds 0.99. According to station records the LaSalle diesels have been started over 450 times with only three valid failures, cince the start of 1984.

A We have calculated that the probability of losing offsite power during a 30 day period is approximately 9.5 x 10-4 If the unit auxiliary transformer on the unit in shutdown is energized, the probability of a LOSP event drops to 1.5 x 10-4 since there are now three connections between the station and the switchyard. The combined probability that one or both of the remaining ESF Division 1 and 2 diesels fail is about 2.6 x 10-2, and the chances that both of them will fail is 2.1 x 10-3 Therefore, the probability that a LOSP will occur concurrent with an additional diesel failure is 2.5 x 10-5 if the UAT is de-energized or 4.0 x 10-6 if the UAT is energized. The chances that no electrical power will be available to the ESF Division 1 and 2 buses ranges from 2.0 to 0.32 x 10-6 Our calculations are shown in Attachment D.

Attachment E summarizes the results of our analysis of a LOSP event with one unit at full power and one diesel inoperable. Even if one of the remaining diesels fails (worst case single failure), we have determined that the unit can be safely shutdown because RCIC, ADS, and at least three ECCS I loops would be available. Therefore, the consequences would be similar to that described in sections 15.2.6 and 15.2.9 of the UFSAR.

If a LOSP to Unit 1 occurs the operator could manually close the unit tie breakers between 4kV buses 142Y and 242Y so that the Unit 2 System

Auxiliary Transformer can provide power to bus 142Y. In addition the 1A diesel generator will be able to power either bus 141Y or 241Y as needed if normal offsite power is not available to either bus, i

Marked-up copies of the Technical Specifications are attached (Attachment B). A similar change to the Unit 2 Technical Specifications to support modification of the "0" and "1A" diesel generators was approved

( previously (refere'nce (e)).

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i l

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l 2250K

ATTACHMENT 5 PROPOSED CHANGE TO APPENDIX A TECHNICAL SPECIFICATION TO OPERATING LICENSE NPF-Il Revised Pages:

NPF-11 -

3/4 8-1 3/4 8-la

2250K Oh spp.

J ATTACHNENT 0 Statien Blackcut Assess. Tent I. Precacility of Losino Off-Site Power curing a 30 day Perica A. Botn SAT's energized, UAT ce. energized Unreliabilityl creeability2

1. Isolation Events
a. Grid Collacse 1x10-8 8.22x10-10
c. Tornace thry switchyarc 1.6x103 1.32x10-4 .
c. All 345kV lines cut 2.5x107 2.05x10-8 Subtotal 1.32x10-*
2. Events whicn disable both SAT inputs
a. Line fault & breaker (5x10-3)2 1.69x10-7 failure
3. Events which fault both SAT outputs

. a. 345kV bus fault & prot. (0.324)2 7.09x10-4

. system malfunction

. b. SAT fault (0.127)2 1.09x10-4 Subtotal o.aoxAu--

Total 9.5x10-4 B. Octh SAT's and UAT energized Failure Event Unreliabilityl Prebability2

1. Isolation events (Same as I.A.1) 1.32x10-4
2. All aux. transformer inputs cisaolec
a. Line fault & breaker (5x10-3)3 6.95x10-ll failure
3. All aux. transformer outputs disabled
a. 345kV bus fault & prot. (0.324)3 1.89x10-5 system malfunction
b. Transformer faults 3 2x(0.127)3 2.28x10-6 Subtotal 2.12x10-3 Total 1.53x10-4 l

0-1 l

- - - - _ _ - _ , . . - . . - _ -. . . . . - - - _ . . _ . . - __.1

Notes: (1) Unreliacility = prob. of failure event / year (frcm ref. 3)

For multiple incepencent failure events such as transformer faults:

Unreliaoility = (creb. of failure event 1/ year) x

.(prob. of failure event 2/ year) x (prce. of failure event n/ year)

(2) P ccacility = precacility of failure event /30 cays a unreliacility x 30/365 For multicle ince encent events:

Precacility = (unreliability of event 1 x30/365) x (unrellacility of event 2 x30/365)

  • x (unreliability of event n x30/365)

(3) The orceability that all three aux. transformers fail curing tne same 30 cay period is: -

unreliacility of SAT 142 x 30/365+

unreliability of SAT 242 x 30/365+

(unreliacility of UAT + pcwer transformer) x 30/365 ,

assuming all 4 transformers have the same unreliacility, the precacility is *

(0.127x30/365) x (0.127x30/365) x -

(0.127+

4 x (2x0.127) x (0.127)Q.127) 2.2Sx10-6

= x 30/365 =2x(0.127)3 x (3 II. Arceability of a Diesel Generater Failure Assumptions: CG-0 Inoceraole Unit 1 in colo shutcown A. One or actn of the Remaining stancby Olesels (LA anc ZA) Fall en Cemanc+

Failure Event Prebacility

1. Random Failures 2
a. OG-1A fails 0.01
b. OG-2A fails 0.01
c. Seth 1A and 2A fail 0.0001
2. Ccmmen Moce Failures 3
a. CG-1A & 2A 0.002
b. OC-LA & 28 0.002 i c. OG-2A & 28 0.CO2 i

Tctal 0.0261

\ -

l 0-2 l

8. Octn CC's 14 ano 2A Fail en Ceeano Failure Event Precability Random failures 2 0.0001 Ccmmon Moce Fa11ures3 0.C02 Total U~0LTi Notes: (1) The Calculatiens will yield the same valve no matter whicn of tne enree stancey ciesels is initially assumed to ce inoperaole.

(2) The Orceability for a randem failure is basto on CCerational experience (references (c), (e), anc (f)).

(3) The value for the commen moce failure is from reference (o).

III. Precacility of a LOSP anc Diesel Failure

. A. LOSP and One or Both Diesels Fails

1. UAT De-energized Prce.' r. 9.5x10-4x2.16x10-2 = 2.48x10-5
2. UAT Energizec Prce. = 1.53 x10-4x2.61x10-2 , 3,99x10-6
8. LOSP anc Botn Diesels Fall
1. UAT Oe-energized Prco. = 9.5x10-Ax2.1x10-3 = 2.0x10-4
2. UAT Energized Proc. = 1.53x10-4x2.1x10-3 = 3.21x10-7 l

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I 0-3 0528K l

i

  • O ATTACH {NT E Loss of Off-Site Pcwer Transient Analysis A. Unit 1 initially at full power, Unit 2 in colo shutcown, and CG-2A inoceracle. -
1. OG-0 fails:

Incceracie Systems Functional Systems RHR Loco A WCS LFCS ADS e RHR Leccs 6 anc C RCIC

2. CG-1A fails:

Inocerable Systems Functional Systems RHR Locos 8 and C WCS '

ACS -

RCIC mR Lxo A -

LPCS -

3. CG-1B rails:

Inoceraole System Functienal Systems WCS A05 RCIC LPCS RHR Loops A, 8, anc C Note: dith Unit 1 at power, OG-0 or 1A will not be allowea to be taken cut of service for an extendec time.

S. Unit 2 initially at full pcwer, Unit i in cela shutccwn, anc OC-1A incoeraois.

1. 0C-0 fails:

same as A.1

2. CC-2A fails:

same as A.2

3. CC-28 fails:

same as A.3 E-1

1 ATTACHMENT C SIGNIFICANT HAZARDS CONSIDERATION l

Ccemonwealth Edison has evaluated the proposed Technical Specification Amendment and determined that it does not represent a significant hazards consideration. Based on the criteria for defining a significant hazards consideration established in 10 CFR 50.92, operation of LaSalle County Station Unit 1 in accordance with the proposed amendment will not:

1) Involve a significant increase in the probability or consequences of an accident previously evaluated because in the event of a loss of offsite power with the "2A" diesel inoperable for this period sufficient onsite power with a single active failure will still be available to safely shutdown.
2) Create the possibility of a new or different kind of accident from any accident previously evaluated because emergency power is ,still available to those systems required to mitigate accidents evaluated in the FSAR.
3) Involve a significant reduction in the margin of safety because the

! probability of a loss of offsite power in addition to a remaining

[ diesel generator failure during the period of these diesel l generator modifications is sufficiently small to reasonably assure t

the health and safety of the public.

Based on the preceding discussion, it is concluded that the proposed system change clearly falls within all acceptable criteria with respect to the system or component, the consequences of previously evaluated accidents will not be increased and the margin of safety will not be l

decreased. Therefore, based on the guidance provided in the Federal j Register and the criteria established in 10 CFR 50.92(c), the proposed change does not constitute a significant hazards consideration.

F l

l l

l 2250K

M

  • For a 30 day period for diesel generator 2A during the Unit 2 first refueling outage, with Unit 2 in operational condition 4 or 5 or defueled, only 3 diesel generators, 18 and 1A, and 0 are required to satisfy the standby AC onsite power requirements for Unit 1. Surveillance requirements,4.8.1.1.la and 4.'8.1.1.2a.4 shall be performed within 48 hours5.555556e-4 days <br />0.0133 hours <br />7.936508e-5 weeks <br />1.8264e-5 months <br /> prior to removal of the 2A diesel generator from service. During the 30 day period the remaining 3 diesel generators will be verified 1 operable at least once per day (in addition to any testing required by Table 4.8.1.1.2-1). The control circuit for the unit cross-tie circuit breakers between buses 142Y and 242Y shall be temporarily modified to allow the breakers to be closed with the diesel generator feeding the bus. In the event these conditions are not met, Unit I will be brought to NOT SHUTDOWN within 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> and COLD SHUTDOWN within the following 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />.

The provisions of Technical Specification 3.0.4 do not' apply.

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i 1 The term verify as used in this context means to administrative 1y check by examining logs or other information to determine if certain components are out-of-service for maintenance or other reasons. It does not mean to perform the surveillance requirements needed to demonstrate the OPERABILITY of the components.

LASALLE - UNIT 1 3/4 8-la 2250K i

. C. Unit 2 initially at full power, Unit 1 in colo shutccwn, anc CC-0 inoperacie.

1. CC-1A fails:

Inoceracle Systems Functional Systems RHR Lcop A HPCS LPCS ADS RHR Lccps B and C RCIC

2. CC-2A fails:

Inceerable Systems Functional Systems RHR Loop A WCS LPCS A05

~

RCIC RHR Locos 8 and C -

after unit tie breakers closec

3. OG-2B fails:

Inoceracle Systems Functional Systems WCS AOS RHR Loco A RCIC LPCS RHR Lceps 8 and C E-2 0528K

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