ML18033B442

Proposed Tech Specs Assuring Availability of Emergency Power from Unit 3 to Support Unit 2 Operation

ML18033B442
Person / Time
Site:	Browns Ferry
Issue date:	07/13/1990
From:	TENNESSEE VALLEY AUTHORITY
To:
Shared Package
ML18033B441	List: ML18033B440 ML18033B442
References
TVA-BFN-TS-283, NUDOCS 9007200113
Download: ML18033B442 (37)

Text

EHCLOSURE 1 PROPOSED TECHHICAL SPECIFICATIOH BROWS FERRYHUCLEAR PLAHT UHITS 2 AHD 3'TVA-BFH-TS&83)

AUXILIARYELECTRICAL SYSTEM

UHIT 2 EFFECTIVE PAGE LIST REMOVE IHSERT 3.9/4.9-15 3.9/4.9-15 3.9/4.9-15a 3.9/4.9-19 3.9/4.9-19*

3.9/4.9-20 3.9/4.9-20 3.9/4.9-21 3.9/4.9-21 3.9/4.9-22 3.9/4.9-22

• Denotes overleaf or spillover page.

4 AUXIL AR TRICAL SYSTEM LIMITIHG COHDITIOHS FOR OPERATIOH SURVEILLAHCE REQUIREMEHTS 3.9.C. 0 eration in Cold Shutdown 4.9.C 0 eration in Cold Shutdown Whenever the reactor is in 1. Ho additional COLD SHUTDOWN COHDITIOH with surveillance is irradiated fuel in the required.

reactor, the availability of electric power shall be as specified in Section 3.9.A except as specified herein.

1. At least two Units 1 and 2 diesel generators and their associated 4-kV shutdown boards shall be OPERABLE.

2. An additional source of power energized and capable of supplying power to the-Units 1 and 2 shutdown boards consisting of at least one of the following:

a. One of the offsite power sources specified in 3.9.A.l.c.

b. A third OPERABLE diesel generator.

3. At least one .480-V shutdown board for each unit must be OPERABLE.

'4. One 480-V RMOV board mg set is required for each RMOV board (2D or 2E) required to support operation of the RHR system in accordance with 3.5.B.9.

BFH 3.9/4.9-15 Unit 2

4 A IL RY C R C SYS LIMITIHG COHDITIOHS FOR OPERATION SURVEILLANCE REQUIREMENTS 3.9.D Unit D esel Ge erators 4.9.D Unit Diesel Generators R u e Oe to e u ed o U t 0 eration

1. Whenever any of the l.a Diesel Generators following equipment is required to be OPERABLE in Surveillance requirements accordance with the are as specified in corresponding section of T.S. 4.9.A.l.a, 4.9.A.l.c, these technical specifi- 4.9.A.l.d and 4.9.A.l.e.

cations, the Unit 3 diesel generator aligned to supply l.b D.C. Power S stem emergency power to that equipment shall be OPERABLE. Surveillance requirements are as specified in T.S.

a. Standby gas treatment 4.9.A.2.

train C in accordance with T.S. 3.7.B (diesel generator l.c Lo ic S stems 3D).

Both divisions of the

b. Control room emergency common accident signal ventilation train B in logic system shall be accordance with T.S. 3.7.E tested every 6 months to (diesel generator 3B or 3C)'. demonstrate that it will function on actuation of

2. When the diesel generator the core spray system of aligned to supply emergency , the reactor to provide power to the equipment in an automatic start signal 3.9.D.l.a or b is inoperable, to each diesel generator.

the equipment may be considered OPERABLE for the purpose of l.d Under Volta e Rela s satisfying the corresponding technical specification during Surveillance requirements the succeeding 30 days provided are as specified in that the redundant train(s) T.S. 4.9.A.4.

of equipment and their normal and emergency power supplies 2. No surveillance required.

are OPERABLE.

3. No surveillance required.

3. If Specification 3.9.D.2 cannot be met, the affected equipment shall be declared.

inoperable.-

BFN 3.9/4.9-15a Unit 2

3.9 BASES AUB 19 1988 The objective of this specification is to assure an adequate source of electrical power to operate facilities to cool the plant during shutdown and to operate the engineered safeguards following an accident. There are three sources of alternating current electrical energy available, namely, the 161-kV transmission system, the 500-kV transmission system, and the diesel generators.

The unit station-service transformer B for unit 1 or the unit

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station-service transformer B for unit 2 provide noninterruptible sources of offsite power from the 500-kV transmission system to the units 1 and 2 shutdown boards. Auxiliary power can also be supplied from the 161-kV transmission system through the common station-service transformers or through the cooling tower transformers by way of the bus tie board. The 4-kV bus tie board may remain out of service indefinitely provided one of the required offsite power sources is not supplied from the 161-kV system through the bus tie board.

The minimum fuel oil requirement of 103,300 gallons is sufficient for seven days of full load operation of three diesels and is conservatively based on availability of a replenishment supply.

The degraded voltage sensing relays provide a start signal to the diesel generators in the event that a deteriorated voltage condition exists on a 4-kV shutdown board. This starting signal is independent of the starting signal generated by the complete loss of voltage relays and will continue to function and start the diesel generators on complete loss of voltage should the loss of voltage relays become inoperable. The 15-day inoperable time limit specified when one of the three phase-to-phase degraded voltage relays is inoperable is justified based on the two-out-of-three permissive logic scheme provided with these relays.

A 4-kV shutdown board is allowed to be out of operation for a brief period to allow for maintenance and testing, provided all remaining 4-kV shutdown boards and associated diesel generators, CS, RHR, (LPCI and containment cooling) systems supplied by the remaining 4-kV shutdown boards, and all emergency 480-V power boards are operable.

There are eight 250-V dc battery systems, each. of which consists of a battery, battery charger, and distribution equipment. Three of these systems provide power for unit control functions, operative power for unit motor loads, and alternative drive power for a 115-V ac unit-preferred mg set. One 250-V dc system provides power for common plant and transmission system control functions, drive power for a 115-V ac plant-preferred mg set, and emergency drive power for certain unit large motor loads. The four remaining systems deliver control power to the 4,160-V shutdown boards.

BFN 3.9/4.9-19 hMENo~,tENT N0. yg g Unit 2

3.9 BASES (Cont'd)

Each 250-V dc shutdown board control power supply can receive power from its own battery, battery charger, or from a spare charger. The chargers are powered from normal plant auxiliary power or from the standby diesel-driven generator system. Zero resistance short circuits between the control power supply and the shutdown board are cleared by fuses located in the respective control power supply. Each power supply is located in the reactor building near the shutdown board it supplies.

Each battery is located in its own independently ventilated battery room.

The 250-V dc system is so arranged, and the batteries sized so that the loss of any one unit battery will not prevent the safe shutdown and cooldown of all three units in the event of the loss of offsite power and a design basis accident in any one unit. Loss of control power to any engineered safeguard control circuits is annunciated in the main control room of the unit affected. The loss of one 250-V shutdown board

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battery affects normal control power for the 480-V and 4,160-V shutdown boards which it supplies. The station battery supplies loads that are not essential for safe shutdown and cooldown of the nuclear system.

This battery was not considered in the accident 1'oad calculations.

There are two 480-V ac RMOV boards that contain mg sets in their feeder lines. These 480-V ac RMOV boards have an automatic transfer from their normal to alternate power source (480-V ac shutdown boards). The mg sets act as electrical ksolators to prevent a fault from propagating between electrical divisions due to an automatic transfer. The 480-V ac RMOV boards involved provide motive power to valves associated with the LPCI mode of the RHR system. Having an mg set out of service reduces the assurance that full RHR (LPCI) capacity will be available when required. Since sufficient equipment is available to maintain the minimum complement required for RHR (LPCI) operation, a 7-day servicing period is justified. Having two mg sets out of service can considerably reduce equipment availability; therefore, the affected unit shall be placed in Cold Shutdown within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />.

The offsite. power source requirements are based on the capacity of the respective lines. The Trinity line is limited to supplying two operating units because of the load limitations of CSST's A and B. The Athens line is limited to supplying one operating unit because of the load limitations of the Athens line. The limiting .conditions are intended to prevent the 161-kV system from supplying more than two units in the event of a single failure in the offsite power system.

Specification 3.9.D provides the operability requirements for the Unit 3 diesel generators when they serve as emergency power supplies to standby gas treatment train C and control room emergency ventilation train B when they are being considered operable for .Unit 2 technical specifications. The allowable out of service time of 30 days is commensurate with the importance of the affected systems when Unit 3 is in cold shutdown, the low probability of a LOCA/Loss of offsite power and availability of onsite power to redundant trains.

BFN'nit 3.9/4.9-20 2

4.9 gASZS (Cont'd) 1 The monthly tests of the diesel generators are primarily to check for failures and deterioration in the system since last use. The diesels will be loaded to at least 100 percent of its continuous rating (i.e.,

g 2600 1N) while engine and generator temperatures are stabilized (about one hour). A minimum 75-percent load will prevent soot formation in the cylinders and injection nozzles. Operation up to an equilibrium temperature ensures that there is no overheating problem. The tests also provide an engine and generator operating history to be compared with subsequent engine-generator test data to identify and to correct any mechanical or electrical deficiency before it can result in a system failure.

Diesel testing once per 18 months (i.e., at least once per fuel cycle) at a minimum load of 2800 KW for an interval of not less than 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> assures that each diesel generator will be capable of supplying the maximum load during the first 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> of a loss of offsite power/loss of coolant accident. This test also demonstrates each diesel generator's long-term load carrying capability.

The test during refueling outages is more comprehensive, including procedures that are most effectively conducted at that time. These include automatic actuation and functional capability tests to verify that the generat'ors can start and be ready to assume load in 10 seconds. The annual inspection will detect any signs of wear long before failure.

BFH tests the 7-day diesel generator fuel oil supplies in accordance with Table 1 of ASTM-D975-89. Each fuel oil supply is tested quarterly.

Battery maintenance with regard to the floating charge, equalizing charge, and electrolyte level will be based on the manufacturer's instruction and sound maintenance practices. In addition, written records will be maintained of the battery performance. The plant batteries will deteriorate with time but precipitous failure is unlikely. The type of surveillance called for in this specification is that which has been demonstrated through experience to provide an indication of a cell becoming irregular or unserviceable long before it becomes a failure.

The equalizing charge, as recommended by the manufacturer, is vital to maintaining the ampere-hour capacity of the battery and will be applied as recommended..=

The testing of the logic systems will verify the ability of the logic systems to bring the auxiliary electrical system to running .standby readiness with the presence of an accident signal from any reactor or an undervoltage signal on the 4-kV shutdown boards.

BFN 3.9/4.9-21

.,Unit 2

4.9 BASES (Cont'd)

The periodic simulation of accident signals in conjunction with diesel generator. voltage available signals will confirm the ability of the 480-V load shedding logic system to sequentially shed and restart 480-V loads if an accident signal were present, and diesel generator voltage were the only source of electrical power.

Specification 4.9.D provides surveillance requirements for Unit 3 diesel generators for the purpose of satisfying Specification 3.9.D. It contains less stringent testing requirements for the Unit 3 diesel generators when they are only being used to support Unit 2 equipment.

~REFZRE CES

1. Hormal Auxiliary Power System (BFHP FSAR Subsection 8.4)

2. Standby AC Power Supply and Distribution (BFHP FSAR Subsection 8.5)

3. 250-V DC Power Supply and Distribution (BFHP FSAR Subsection 8.6)

4. Memorandum from Gene M. Wilhoite to H. J. Green dated December 4, 1981 (LOO 811208 664) and memorandum from C. E. Winn to H. J. Green dated January 10, 1983 (G02 830112 002)

BFH 3.9/4.9-22 Unit 2

UHIT 3 EFFECTIVE PAGE LIST IHSERT 3.9/4.9-13 3.9/4.9-13*

3.9/4.9-14 3.9/4.9-14 3.9/4.9-14a 3.9/4.9 14b 3.9/4.9-18 3.9/4.9-18*

3.9/4.9-19 3.9/4.9-19 3.9/4.9-20 3.9/4.9-20%'.9/4.9-21 3.9/4.9-21

• Denotes overleaf or spillover page.

4 A LIARY C R CAL SYSTEM NOV 18'l988 LIMITIHG COHDITIOHS FOR OPERATIOH SURVEILLAHCE REQUIREMEHTS 3.9.B 0 eration With o erab1e g~gm~t

10. .When one 480-V shutdown board is found to be inoperable, the reactor will be placed in HOT STANDBY COHDITIOH within 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> and COLD SHUTDOWN CONDITIOH.within 24 hour2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />s:

11. If one 480-V RMOV board mg set is inoperable, REACTOR POWER OPERATIOH may continue for a period not to exceed seven days, provided the remaining 480-V RMOV board mg sets and their associated loads remain OPERABLE.

12. If any two 480-V RMOV board mg sets become inoperable, the reactor shall be placed in the COLD SHUTDOWN COHDITIOH within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />.

13. If the requirements for operation in the conditions specified by 3.9.B.1 through 3.9.B.12 cannot be met, an orderly shutdown shall be initiated and the reactor shall be in the COLD SHUTDOWN CONDITION within 24'ours.

AMENOMBTgg. gpss BFN 3.9/4.9-13 Unit 3

C C S S LIMITIHG COHDITIOHS FOR OPERATIOH SURVEILLAHCE REQUIREMEHTS t

3.9.C. 0 er t on Co d utdown 4.9.C 0 erat o n Cold Shutdo

~Co zitig Whenever the reactor is in the 1. Ho additional COLD SHUTDOWH COHDITIOH with surveillance is irradiated fuel in the required.

reactor, the availability of electric power shall be as specified in Section 3.9.A except as specified herein.

1. At least two Unit 3 diesel generators and their associated 4-kV shutdown boards shall be OPERABLE.

2. An additional source of power energized and capable of supplying power to the Unit 3 shutdown boards consisting of at least one of the following:

a. One of the offsite power sources specified in 3.9.A.l.c.

b. A third OPERABLE diesel generator.

3. At least one Unit 3 480-V shutdown board must be OPERABLE.

4. One 480-V RMOV board motor generator (mg) set is required for each RMOV board (3D or 3E) required to support operation of the RHR system in accordance with 3.5.B.9.

'FH 3.9/4.9-14 Unit 3

4 A TRICAL S S LIMITIHG COHDITIOHS FOR OPERATIOH SURVEILLANCE REQUIREMENTS 3.9.D Unit Diese Generators 4.9.D Unit Diesel Generators Re ui d for Un 2 0 eration Re uired for Unit 2 0 eration

1. Whenever any of the l.a Diesel Generators following equipment is required to be OPERABLE in Surveillance requirements accordance with the are as specified in corresponding section of T.S. 4.9.A.l.a, 4.9.A.l.c, any units technical specifi- 4.9.A.l.d and 4.9.A.l.e.

cations, the Unit 3 diesel generator aligned to supply l.b D C. Power S stem emergency power to that equipment shall be OPERABLE. Surveillance requirements are as specified in T.S.

a. Standby gas treatment 4.9.A.2.

train C in accordance with T.S. 3.7.B (diesel generator l.c Lo ic S stems 3D).

Both divisions of the

b. Control room emergency common accident signal ventilation train B in logic system shall be accordance with T.S. 3.7.E tested every 6 months to (diesel generator 3B or 3C). demonstrate that it will function on actuation of

2. When the diesel generator the core spray system of aligned to supply emergency the Unit 2 reactor to power to the equipment in provide an automatic start 3.9.D.l.a or b is inoperable, signal to each diesel the equipment may be considered generator.

OPERABLE for the purpose of satisfying the corresponding l.d Under Vo ta e Rela s technical specification during the succeeding 30 days provided Surveillance requirements that the redundant train(s) are as specified in of equipment and their normal T.S. 4.9.A.4.

and emergency power supplies are OPERABLE. 2. No surveillance required.

3. If Specification 3.9.D.2 3. No surveillance required.

cannot be met, the affected equipment shall be declared inoperable.

BFN 3.9/4.9-14a Unit 3

THIS PAGE IHTEHTIOHALLYLEFT BLAHK BFH ~ 3.9/4.9-14b Unit 3

V % h 9 ~BSES ~ AUB <9m The objective of this specification is to assure an adequate source of electrical power to operate facilities to cool the unit during shutdown "and to operate the engineered safeguards following an accident. There are three sources of alternating current electrical energy available, namely, the 161-kV transmission system, the 500-kV transmission system, and the diesel generators.

The unit station-service transformer B for unit 3 provides a noninterruptible source of offsite power from the 500-kV transmission system to the unit 3 shutdown boards. Auxiliary power can also be supplied from the 161-kV transmission system through the common station-service transformers or through the cooling tower transformers by way of the bus tie board. The 4-kV bus tie board may remain out of service indefinitely provided one of the required offsite power sources is not supplied from the 161-kV system through the bus tie board.

The minimum fuel oil requirement of 103,300 gallons is sufficient for seven days of full load operation of three diesels and is conservatively based on availability of a replenishment supply.

The degraded voltage sensing relays provide a start signal to the diesel generators in the event that a deteriorated voltage condition exists on a 4-kV shutdown board. This starting signal is independent of the starting signal generated by the complete loss of voltage relays and will continue to function and start the diesel generators on complete loss of voltage should the loss of voltage relays become inoperable.

The 15-day inoperable time limit specified when one of the three phase-to-phase 'degraded voltage relays is inoperable is justified based on the two-out-of-three permissive logic scheme provided with these relays.

A 4-kV shutdown board is allowed to be out of operation for a brief period to allow for maintenance and testing, provided all remaining 4-kV shutdown boards and associated diesel generators, CS, RHR, (LPCI and containment cooling) systems supplied by the remaining 4-kV shutdown boards,. and all emergency 480-V power boards are operable.

The 480-V diesel auxiliary board may be out of service for short periods for tests and maintenance. There are five 250-V dc battery systems associated with unit 3, each of which consists of a battery, battery charger, and distribution equipment. Three of these systems provide power for unit control functions, operative power for unit motor loads, and alternative drive power for a 115-V ac unit-preferred mg set. One 250-V dc system provides power for common plant and transmission system control functions, drive power for a 115-V ac plant-preferred mg set, and emergency drive power for certain unit large motor loads. The fifth battery system delivers control power to a 4-kV shutdown board.

BFN 3.9/4.9-18 AMENENEHTHK T EC Unit 3

3.9 /USES (Cont'd)

The 250-V dc system is so arranged and the batteries sized so that the loss of any one. unit battery vill not prevent the safe shutdown and, cooldown of all three units in the event of the loss of offsite power and a design basis accident in any one unit. Loss of control pover to any engineered safeguard control circuits is annunciated in the main control room of the unit affected.

The station battery supplies loads that are not essential for safe shutdown and, cooldown of the nuclear system. This battery vas not considered in the accident load calculations.

There are two 480-V ac RMOV boards that contain mg sets in their feeder lines. These 480-V ac RMOV boards have an automatic transfer from their normal to alternate pover source (480-V ac shutdown boards). The mg sets act as electrical isolators to prevent a fault from propagating between electrical divisions due to an automatic transfer. The 480-V ac RMOV boards involved provide motive pover to valves associated vith the LPCI mode of the RHR system. Having an mg set out of service reduces the assurance that full RHR (LPCI) capacity vill be available when required. Since sufficient equipment is available to maintain the minimum complement required for RHR (LPCI) operation, a 7-day servicing period is justified. Having tvo mg sets out of service can considerably reduce equipment availability; therefore, the, affected unit shall be placed in Cold Shutdovn vithin 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />.

\

The offsite pover source requirements are based on the capacity of the respective lines. The Trinity line is limited to supplying two operating units because of the load limitations of CSST's A and B. The Athens line is limited to supplying one operating unit because of the load limitations of the Athens line. The limiting conditions are intended to prevent the 161-kV system from supplying more than tvo units in the event of a single failure in the offsite power system.

Specification 3.9.D provides the operability requirements for the Unit 3 diesel generators vhen they serve as emergency pover supplies to standby gas treatment train C and control room emergency, ventilation train B when they are being considered operable for Unit 2 technical specifications. The allovable out of service time of 30 days vith the importance of the affected systems vhen Unit 3 is is'ommensurate in cold shutdown, the lov probability of a LOCA/Loss of offsite pover and availability of onsite pover to redundant trains; BFN 3.9/4.9-19 Unit 3

4.9 BAszs (cont'd)0 The monthly tests of the diesel generators are primarily to check for failures and deterioration in the system since last use. The diesels will be loaded to at least 100 percent of its continuous rating (i.e. 2 2600 KH) while engine and generator temperatures are stabilized (about one hour). A minimum 75-percent load will prevent soot formation in the cylinders and injection nozzles. Operation up to an equilibrium temperature ensures that there is no overheating problem. The tests also provide an engine and generator operating history to be compared with subsequent engine-generator test data to identify and to correct any mechanical or electrical deficiency before it can result in a system failure.

Diesel testing once per 18 months (i.e., at least once per fuel cycle) at, a minimum load of 2800 KW for an interval of not less than 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> assures that each diesel generator will be capable of supplying the maximum load during the first 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> of a loss of offsite power/loss of coolant accident. This test also demonstrates each diesel generator's long-term load carrying capability.

The test during refueling outages is more comprehensive, including procedures that are most effectively conducted at that time. These include automatic actuation and functional capability tests to verify that the generators can start and be ready to assume load in 10 seconds. The annual inspection will detect any signs of wear long before failure.

BFH tests the 7-day diesel generator fuel oil supplies in accordance with Table 1 of ASTM-D975-89. Each fuel oil supply is tested quarterly.

Battery maintenance with regard to the floating charge, equalizing charge, and electrolyte level will be based on the manufacturer's instruction and sound maintenance practices. In addition, written records will be maintained of the battery performance. The plant batteries will deteriorate with time but precipitous failure is unlikely. The type of surveillance called for in this specification is that which has been demonstrated through experience to provide an indication of a cell becoming irregular or unserviceable long before it becomes a failure.

The equalizing charge, as recommended by the manufacturer, is vital to maintaining the ampere-hour capacity of the battery and will be applied as recommended.

The testing of the logic system will verify the ability of the logic systems to bring the auxiliary electrical system to running standby readiness with the presence of an accident signal from any reactor or an undervoltage signal on the start buses or 4-kV shutdown boards.

The periodic simulation of accident signals in conjunction with diesel generator voltage available signals will confirm the ability of the 480-V load shedding logic system to sequentially shed and restart 480-V loads if an accident signal were present, and diesel generator voltage were the only source of electrical power.

BFN 3.9/4.9-20 Unit 3

4.9 BASES (Cont' Specification 4.9.D provides surveillance requirements for Unit 3 diesel generators for the purpose of sati'sfying Specification 3.9.DE contains less stringent testing requirements for the Unit 3 diesel generators when they are only being used to support Unit 2 equipment.

References

1. Hormal Auxiliary Power System (BFHP FSAR Subsection 8.4)

2. Standby AC Power Supply and Distribution (BFHP FSAR Subsection 8.5)

3. 250-V DC Power Supply and Distribution (BFHP FSAR Subsection 8.6)

4. Memorandum from G. M. Wilhoite to H. J. Green dated December 4, 1981 (LOO 811208 664) and memorandum from C. E. Winn to H. J. Green dated January 10, 1983 (G02 830112 002)

BFN 3.9/4.9-21 Unit .3

ENCLOSURE 2

SUMMARY

OF CHANGES UNIT 2

1. Add Specification 4.9.C 4.9.C 0 eration in Cold Shutdown

1. No additional surveillance is required.

2. Add Specification 3.9.D 3.9.D Unit 3 Diesel Generators Re uired for Unit 2 0 eration

1. Whenever any of the following equipment is required to be OPERABLE in accordance with the corresponding section of these technical specifications, the unit 3 diesel generator aligned to supply emergency power to that equipment shall be OPERABLE.

a. Standby gas treatment train C in accordance with TS 3.7.B (diesel generator 3D)

b. Control.,room emergency ventilation train B in accordance with TS 3.7.E (diesel generator 3B or 3C)

2. When the diesel generator aligned to supply emergency power to the equipment in 3.9.D.l.a or b is inoperable, 'the equipment may be considered OPERABLE.;for."the..purpose of satisfying the corresponding technical'pecification during the succeeding 30 days provided that the redundant train(s) of equipment and their normal and emergency power supplies are OPERABLE.

3. If specification 3.9.D.2 cannot be met, the affected equipment shall be declared inoperable.

3. Add Specification 4.9.D 4.9.D Unit 3 Diesel Generators Re uired for Unit 2 0 eration l.a Diesel Generators Surveillance requirements are as specified in TS 4.9.A.l.a, 4.9.A.l.c, 4.9.A.l.d and 4.9.A.l.e.

l.b D.C. Power S stem Surveillance requirements are as specified in TS 4.9.A.2.

Both divisions of the common accident signal logic system shall be tested every 6 months to demonstrate that it will function on actuation of the core spray system of the reactor to provide an automatic start signal to each diesel generator.

Enclosure 2 Page 2 of 5 l.d Under Volta e Rela s Surveillance requirements are as specified in TS 4.9.A.4.

2. No surveillance required.

0

3. No surveillance required.

4. Revise bases section 3.9 Existing bases reads in part on page 3.9/4.9-20:

"The loss of one 250-V shutdown board battery affects normal control power only for the 4160-V shutdown board which it supplies."

Revised bases section 3.9 would read in part:

"The loss of one 250-V shutdown board battery affects normal control power for the 480-V and 4160-V shutdown boards which it supplies."

Add the following to bases section 3.9:

"Specification 3.9.D provides the operability requirements for the unit 3 diesel generators when they serve as emergency power supplies to standby gas treatment train C and control room emergency ventilation train B when they are being considered operable for unit 2 technical specifications.

The allowable out of service time of 30 days is .commensurate with the importance of the affected systems when unit 3 is in cold shutdown, the low probability of a LOCA/Loss of Offsite Power and availability of onsite power to redundant trains."

5. Revise bases section 4.9 Existing bases reads in part on page 3.9/4.9-21:

"The test during refueling outages is more comprehensive, including procedures that are most effectively conducted at that time. These include automatic actuation and functional capability tests to verify that the generators can start and be ready to assume load in 10 seconds.

The annual inspection will detect any signs of wear long before failure.

The diesel generators are shared by units 1 and 2. Therefore, the capability for the units 1 and 2 diesel generators to accept the emergency loads will be performed during the unit 1 operating cycle using the unit 1 loads."

Revised bases section 4.9 would read in part:

"The test during refueling outages is more comprehensive, including procedures that are most effectively conducted at that time. These include automatic actuation and functional capability tests to verify that the generators can start and be ready to assume load in 10 seconds.

The annual inspection will detect any signs of wear long before failure."

Enclosure 2 Page 3 of 5 Add the following to bases section 4.9:

"Specification 4.9.D provides surveillance requirements for unit 3 diesel generators for the purpose of satisfying specification 3.9.D. It contains less stringent testing requirements for, the unit 3 diesel generators when they are only being used to support unit 2 equipment."

AIMS' ~'

Enclosure 2 Page 4 of 5

SUMMARY

OF CHANGES UNIT 3

1. Add Specification 4.9.C 4.9.C 0 eration in Cold Shutdown

1. No additional surveillance is required.

2. Add Specification, 3.9,.D 3.9.D Unit 3 Diesel Generators Re uired for Unit 2 0 eration

1. Whenever any of the following equipment is required to be OPERABLE in accordance with the corresponding section of any units technical specifications, the unit 3 diesel generator aligned to supply emergency power to that equipment shall be OPERABLE.

a. Standby gas treatment train C in accordance with TS 3.7.B (diesel generator 3D)

b. Control room emergency ventilation train B in accordance with TS 3.7.E (diesel generator 3B or 3C)

2. When the diesel generator aligned to supply emergency power to the equipment in 3.9.D.l.a or b is inoperable, the equipment may be considered OPERABLE.:far..the purpose of satisfying the corresponding technical'pecification during the succeeding 30 days provided that the redundant train(s) of equipment and their normal and emergency power supplies are OPERABLE.

3. If specification 3.9.D.2 cannot be met, the affected equipment shall be declared inoperable.

3. Add Specification 4.9.D 4.9.D Unit 3 Diesel Generators Re uired for Unit 2 0 eration l.a Diesel Generators Surveillance requirements are as specified in TS 4.9.A.l.a, 4.9.A.l.c, 4.9.A.l.d and 4.9.A.l.e.

l.b D.C. Power S stem Surveillance requirements are as specified in TS 4.9.A.2.

Both divisions of the common accident signal logic system shall be tested every 6 months to demonstrate that it will function on actuation of the core spray system of the unit 2 reactor to provide an automatic start signal to each diesel generator.

Enclosure 2 Page 5 of 5 l.d Under Volta e Rela s Surveillance requirements are as specified in TS 4.9.A.4.

2. No Surveillance Required.

3. No Surveillance Required.

4. Add the following to bases section 3.9:

"Specification 3.9.D provides the operability requirements for the unit 3 diesel generators when they serve as emergency power supplies to standby gas treatment train C and control room emergency ventilation train B when they are being considered operable for unit 2 technical specifications.

The allowable out of service time of 30 days is commensurate with the importance of the affected systems when unit 3 is in cold shutdown, the low probability of a LOCA/Loss of Offsite Power and availability of onsite power to redundant trains."

-5. Add the following to bases section 4.9:

".Specification 4.9.D provides surveillance requirements for unit 3 diesel generators for the purpose of satisfying specification 3.9.D. It contains less stringent testing requirements for the unit 3 diesel generators when they are only being used to support unit 2 equipment.

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ENCLOSURE 3 REASONS AND JUSTIFICATION FOR CHANGES Reason for Chan e BFN unit 2 and 3 technical specifications (TS) 3.9 for the Auxiliary Electrical System are being revised to reflect requirements on the availability of emezgency power from unit 3 to support unit 2 operation. This change reflects the plant configuration wherein some trains or subsystems of specific systems that are shared by all three units are provided standby power by the unit 3 emergency diesel generators (EDGs).

The NRC, by letter to 0. D. Kingsley dated 12/21/89, requested the unit 2 technical specifications be revised prior to restart to specifically include operability requirements for the unit 3 EDGs to support this equipment.

The bases for specification 4.9 are also changed to delete two sentences which indicate that the capability of the units 1 and 2 EDGs to accept emergency loads will be performed during the unit 1 operating cycle using the unit 1 loads. Unit 1 is presently shutdown and defueled. In light of this, TVA has tested the EDGs as part of its restart test program. Results are documented in the Diesel Generator Evaluation Report, submitted to the NRC by letter dated January 20, 1989.

Further, the bases for specification 3.9 are being revised to reflect the fact that the loss of a 250 V shutdown board battery affects the control power for both the 480 V and the 4160 V shutdown boards. This revision is the result of a modification which reassigned the normal 250 V DC control. power supply of 480 V AC shutdown boards lA, 1B, 2A and 2B from the plant unit batteries to the 4160 V AC shutdown board batteries SB-A, SB-B, SB-C and SB-D. The modification resolved a problem documented in Significant Condition Report which involved a failure of a unit battery resulting in the loss of the ability to control the breakers fed from the 480 V shutdown boards, and the loss of a 250 V reactor NOV board.

Justification for the Chan es The change to the unit 2 and unit 3 technical specifications reflects the requirement that the unit 3 EDGs must be operable to support equipment for unit 2 operation. EDG 3C provides emergency power to the Control Room Emergency Ventilation System (CREVS), train B. Electrical alignment can also be made to supply power from EDG 3B. EDG 3D provides emergency power to the Standby Gas Treatment System, train C. This change does not affect the EDG requirements for RHRSW pumps A3 and C3 because their function is only required as an alternative to the unit 1/2 pumps for EECW service.

This change establishes the specific requirements for unit 3 EDGs for the condition where unit 3 is in cold shutdown condition or defueled and specific CREVS or SGTS trains are required to support unit 2. Technical Specification definition E currently r'equires operability of the emergency power supply in order to consider a piece of equipment operable. Definition 1.C.2 contains an exception to this requirement (that applies only when the unit is not in cold shutdown or refuel) which allows the limiting condition for operation for EDGs to govern required actions. These definitions do not explicitly address the situation where the 'unit being served (i.e., unit 2) is not in cold shutdown

Enclosure 3 Page 2 of 2 but unit 3 is in cold shutdown or defueled. The limiting condition for operation for unit 3 EDGs is not specified in this case and is determined by prudent judgment and administrative controls. The effect of this change is to impose an explicit 30-day limit in the technical specifications for the diesel generators which supply power to SGTS Train C and CREVS Train B. These are common subsystems which are required 'by technical specifications for unit operation and fuel handling. Therefore, this change results in a more limiting technical specification requirement than is currently specified.

The 30-day allowed out-of-service time is justified based upon the decreased reliance on unit 3 EDGs when unit 3 is in cold shutdown or defueled. Under these conditions the remaining equipment and EDGs are capable of responding to an accident and/or loss of offsite power. T.S. 3.9.D serves to enforce conservative actions in the event that the unit 3 EDGs supplying emergency power to SGTS Train C or CREVS Train B become inoperable, because the existing unit 2 technical specifications are based upon these trains being considered operable with no requirement for the operability of unit 3 EDGs. The existing unit 2 technical specifications in definition 1.C.2 allow continuous operation with no restrictions whereas the proposed section 3.9.D limits the condition to 30 days. Because it is more restrictive this change does not adversely affect safety Surveillance requirements are specified for the unit 3 EDGs, D.C. batteries, diesel generator logic, and under voltage detection relays, to assure continued operability. All of the testing currently required for EDG's associated with a fully operational unit will be implemented with the exception of the following. Tests associated with the~.loss. of offsite power/LOCA response of the system to a unit 3 accident- are not required when unit 3 is defueled. Surveillance requirements therefore exclude this condition. All of the testing requirements for diesel generator logic, D.C.

batteries which support the required EDGs, and under voltage detection relays that would be required for a fully operational unit will be applicable.

t The bases for unit 2 specification 3.9 are also modified to reflect changes resulting from the implementation of an engineering change. The revision to the bases reflects the fact that loss of a 250 V shutdown board battery affects the control power for both 480 V and 4160 V shutdown boards.

The bases for unit 2 specification 4.9 are changed to delete reference to the use of unit 1 loads to demonstrate the capability of, the units 1 and 2 EDGs to accept emergency loads. Unit 1 is presently shutdown and defueled.

Accordingly, TVA has tested the EDGs as part of its unit 2 restart test program which includes EDG response to a unit 2 loss of offsite power (LOP)/Loss of coolant accident (LOCA) loads application. Voltage and frequency responses were analyzed for acceptability based on transient and steady state voltage and frequencies not exceeding the electrical equipment design. NRC review of this unit 2 Emergency Diesel Generator Loading Analysis has been documented in safety evaluation dated December 21, 1989.

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~ 'll 0 1I ENCLOSURE 4 PROPOSED DETERNINATION OF NO SIGNIFICANT HAZARDS CONSIDERATION BROWNS FERRY NUCLEAR PLANT (BFN)

Descri tion of Pro osed Technical S ecification Chan es The proposed TS change will: (1) add specification 3.9.D for unit 2 and unit 3 to require that whenever Standby Gas Treatment train C and/or the Control Room Emergency Ventilation train B are required for unit 2 operation, the associated unit 3 diesel generator be operable. Specification 3.9.D additionally specifies that when the diesel generator aligned to supply this emergency power is inoperable, the equipment may be considered operable for the purpose of satisfying corresponding technical specifications during the succeeding 30 days, provided the redundant train(s) of equipment and their normal and emergency power supplies are operable, and if these specifications cannot be met, then the effected equipment shall be declared inoperable. (2)

The proposed technical specification also will add specification 4.9.D for unit 2 and unit 3 to define the surveillance requirements for unit 3 diesel generators required for unit 2 operation with unit 3 shutdown, (3) add specification 4.9.C for unit 2 and unit 3 to clarify that no additional surveillance is required during operation in cold shutdown, (4) supplement the bases for unit 2 and unit 3 specification 3.9 with a paragraph to address the new requirements for the unit 3 diesel generators. In addition, changes to the 3.9/4.9 bases to cover two changes not related to the unit 3 diesel generator requirements are enclosed. These delete two sentences from the bases for specification 4.9 which refer to the use of unit 1 loads to assess the capability of units 1 and 2 emergency diesel'enerators (EDGs) to accept emergency loads, and modify the bases for unit 2 speci@.cation 3.9 to reflect that 480 V shutdown boards are affected by the loss of a 250 V shutdown board battery.

Basis for Pro osed No Si nificant Hazards Consideration Determination NRC has provided standards for determining whether a significant hazards consideration exists as stated in 10 CFR 50.92(c). A proposed amendment to an operating license involves no significant hazards 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, or 2) create the possibility of a new or different kind of accident from any accident previously evaluated, or 3) involve a significant reduction in a margin of safety.

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

The safety objective of the standby power system is to provide a self-contained and highly reliable source of power to the required loads for the safe shutdown and cooldown of all three units in the event of a loss of offsite power and a loss of coolant accident in any one unit.

The safety functions of the Standby Diesel Generator System are not affected by this change to the Technical Specifications. There are no physical changes to the plant as a result of this revision. The Technical Specifications are being revised to provide LCO and surveillance requirements for equipment which is provided emergency power from unit 3. The unit 3 EDGs are already configured to supply

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Enclosure 4 Page 2 of 3 emergency power to the mechanical systems associated with this technical specification change. The change will ensure that plant operators recognize the interdependency to unit 3 EDGs and that surveillances of the unit 3 EDGs are performed to assure continued operability and support of unit 2 operation.

The Standby Gas Treatment System (SGTS) provides a means for minimizing the release of radioactive material from the containment to the environs by filtering and exhausting the air from the three Reactor Building areas and the common refueling area and maintaining the areas at a negative pressure during containment isolation conditions.

The ability to fulfill the safety functions of the SGTS is assured by this change to the Technical Specifications. By requiring unit 3 EDG 3D be operable to support unit 2 operation, emergency power is assured for the operation of train C of the SGTS.

Each train of the SGTS is supplied with emergency power from separate emergency power supplies to ensure that two trains are always available in case of loss of offsite power and the loss of any one train or EDG.

The power supply for trains A and B is from the units 1 and 2 EDGs- A and D. Train C is powered by the unit 3 EDG 3D.

Control logic for the SGTS automatically and concurrently starts all three 50K capacity filter trains upon receipt of an accident signal (low reactor water level, high drywell pressure or high activity in a ventilation exhaust duct). Should one train faik;,".the two remaining trains will continue to provide the required flow.

Either of the two CREVS (100K capacity) trains is capable of supplying clean air to pressurize the control rooms under isolated conditions and thus provide protection from excessive concentrations of airborne activity.

The ability to meet the safety functions of the CREVS is assured by this change to the technical specifications. With the associated diesel generator from unit 3 operable, emergency power is available for the operation of train B of the CREVS. Thus, the fulfillment of the safety function of this system is assured including that required for an event wherein a loss of offsite power occurs.

The changes have no effect therefore on the probability or consequences of an accident previously evaluated for Browns Ferry unit 2. Final Safety Analysis Report Chapter 14 evaluations remain unimpacted.

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

There are no physical changes to the facility. The changes to the technical specifications merely specify operational support of unit 2 by unit 3 EDGs so that power will be supplied to those emergency systems required to mitigate the consequences of accidents.

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

There are no physical changes to the facility and the proposed changes to the technical specifications merely reflect the existing physical conditions.

Surveillance requirements have been instituted to assure the continued operability of the associated emergency power sources necessary for supplying the Standby Gas Treatment and Control Room Emergency Ventilation System requirements.

The Diesel Generator Loading Evaluation qualified the loading, voltage response and frequency response given the following unit 2 postulated operating conditions, a total loss of offsite power, and a loss of coolant accident with concurrent loss of offsite power.

Therefore, there is no effect on any margin of safety and this proposed change does not involve a reduction in any margin of safety.

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