ML18036B200

Proposed Tech Specs Re Surveillance Frequency for Emergency Diesel Generator Maintenance Inspections

ML18036B200
Person / Time
Site:	Browns Ferry
Issue date:	03/19/1993
From:	TENNESSEE VALLEY AUTHORITY
To:
Shared Package
ML18036B199	List: ML18036B198 ML18036B200
References
NUDOCS 9303260245
Download: ML18036B200 (24)

Text

ENCLOSURE 1 PROPOSED TECHNICAL SPECIFICATION CHANGE BROWNS FERRY NUCLEAR PLANT UNITS 1, 2, AND 3 (TVA BFN TECHNICAL SPECIFICATION NO. 332) 9303260245 930319 PDR ADOGK 05000259

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PROPOSED TECHNICAL SPECIFICATION CHANGE BROWNS FERRY NUCLEAR PLANT UNIT 1 (TVA BFN TECHNICAL SPECIFICATION NO. 332)

UNIT 1 EFFECTIVE PAGE LIST REMOVE INSERT 3.9/4.9-3 3.9/4.9-3 3.9/4.9-21 3.9/4.9-21

4.

3.9.A. E t 4.9.A.

3.9.A.l.c. (Cont'd) 4.9.A.l.b (Cont'd)

(4) The Athens 161-kV line is available to the units 1 load sequencing, and and 2 shutdown boards operates for greater through a common than or equal to five station-service minutes while its gener-transformer when unit 1 is ator is loaded with the in Cold Shutdown and unit 3 emergency loads.

is not claiming the Athens line as an offsite source. (3) On diesel generator breaker trip, the loads NOTE FOR (3) AND (4): are shed from the emer-gency buses 'and the diesel With no cooling tower pumps output breaker recloses or fans running, a cooling on the auto-start signal, tower transformer may be the emergency buses are substituted for a common energized with permanently station-service transformer. connected loads, the auto-connected emergency loads are energized through load sequencing, and the diesel operates for greater than or equal to five minutes while its generator is loaded with the emergency loads.

c. Once a month the quantity of diesel fuel available shall be logged.

d. Each diesel generator shall be inspected in accordance with instructions based on the manufacturer's recommendations once every 24 months.

e. Quarterly the quality of each diesel generator's (A, B, C, and D) seven-day fuel supply shall be checked: The fuel oil quality shall be within the acceptable limits specified in Table 1 of ASTM-D975-89.

SFN 3.9/4.9-3 Unit 1

~ . 4.9 3~ (Cont'd)

The monthly test of the diesel generators is 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., ~

2600 KM) 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 maintenance inspection will detect any signs of wear long before failure.

BFN 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.

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 was the only source of electrical power.

BFN 3.9/4.9-21 Unit 1

1 PROPOSED TECHNICAL SPECIFICATION CHANGE BROMNS FERRY NUCLEAR PLANT UNIT 2 (TVA BFN TECHNICAL SPECIFICATION NO. 332)

UNIT 2 EFFECTIVE PAGE LIST REMOVE INSERT 3.9/4.9-3 3.9/4.9-3 3.9/4.9-21 3.9/4.9-21

N 3.9.A. 4.9.A.

3.9.A.l.c. (Cont'd) 4.9.A.l.b. (Cont'd) emergency loads through load sequencing, and operates for greater than or equal to five minutes while its generator is loaded with the emergency loads.

(4) The'Athens 161-kV line is (3) On diesel generator available to the units 1 breaker trip, the and 2 shutdown boards loads are shed from through a common the emergency buses station-service and the diesel output transformer when unit 1 is breaker recloses on in Cold Shutdown and unit 3 the auto-start signal, is not claiming the Athens the emergency buses line as an offsite source. are energized with permanently connected NOTE FOR (3) AND (4): loads, the auto-connected emergency With no cooling tower pumps loads are energized or fans running, a cooling through load tower transformer may be sequencing, and the substituted for a common diesel operates for station-service transformer. greater than or equal to five minutes while its generator is loaded with the emergency loads.

c. Once a month the quantity of diesel fuel available shall be logged.

d. Each diesel generator shall be inspected in accordance with instructions based on the manufacturer's recommendations once every 24 months. I

e. quarterly the quality of each diesel generator's (A, B, C, and D) seven-day fuel supply shall be checked. The fuel oil quality shall be within the acceptable limits specified in Table 1 of ASTM-D975-89.

BPN 3.9/4.9-3 Unit 2

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4.9 Q~ (Cont'd)

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'ating (i.e., g 2600 KW) 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 maintenance inspection will detect any signs of wear long before failure.

BFN 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 f'r 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.

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.

BPN 3.9/4.9-21 Unit 2

'4E PROPOSED TECHNICAL SPECIFICATION CHANGE BROWNS FERRY NUCLEAR PLANT UNIT 3 (TVA BFN TECHNICAL SPECIFICATION NO. 332)

UNIT 3 EFFECTIVE PAGE LIST REMOVE INSERT 3.9/4.9-3 3.9/4.9-3 3.9/4.9-20 3.9/4.9-20

3.9.A. 4.9.A.

3.9.A.l.c.(3) (Cont'd) 4.9.A.l.b. (Cont'd) through load sequencing, and operates for greater than or equal to while its gener-five'inutes ator is loaded with NOTES FOR (2) AND (3): the emergency loads.

If both Athens and (3) On diesel generator Trinity lines are breaker trip, the claimed as the two loads are shed from offsite sources for the emergency buses unit 3, no credit may and the diesel output be taken for the breaker closes on the Athens-Trinity line auto-start signal, the tie breaker. emergency buses are Specifically, the energized with Athens line supplies permanently connected unit 3 through common loads, the auto-station-service connected emergency transformer A or loads are energized cooling tower through load transformer 1, and sequencing, and the the Trinity line diesel operates for must supply unit 3 greater than or equal through common station- to five minutes while service transformer B or its generator is cooling tower loaded with the transformer 2. emergency loads.

c. Once a month the quantity of diesel fuel available shall be loggedo

d. Each diesel generator shall be inspected in accordance with instructions based on the manufacturer's recommendations once every 24 months.

e. Quarterly the quality of each diesel generator's (3A, 3B, 3C, and 3D) seven-day fuel load supply shall be checked. The fuel oil quality shall be within the acceptable limits specified in Table 1 of ASTM-D975-89.

BFN 3.9/4.9-3 Unit 3

4.9 g~Q (Cont'd)

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. Z 2600 KW) 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 maintenance 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 ASTH-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.

BFH 3.9/4.9-20 Unit 3

ENCLOSURE 2 BROMNS FERRY NUCLEAR PLANT (BFN)

UNITS 1, 2, AND 3 (TVA BFN TECHNICAL SPECIFICATION NO. 332)

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REASO FOR THE CHA GE DESCRIPTION AND JUSTIFI ATIO REASON FOR THE CHANGE: The reason for this change is to improve emergency diesel generator availability by providing for extension of the maintenance inspection interval in accordance with revised manufacturer recommendations.

ESCR PTION OF THE PROPOSED CHANG : The proposed amendment changes the emergency diesel generator inspection interval of Surveillance Requirement 4.9.A.l.d from the current requirement of once per year to an interval of 24 months. This change applies to all units.

The existing TSs state at paragraph 4.9.A.l.d (Units l, 2, & 3):

Each diesel generator shall be given an annual inspection in accordance with instructions based on the manufacturer's recommendations'he Bases for paragraph 4.9.A.l.d states:

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

o ose Chan e:

Paragraph 4.9.A.l.d shall be changed to:

Each diesel generator shall be inspected in accordance with instructions based on manufacturer's recommendations once every 24 months.

The Bases for paragraph 4.9.A.l.d shall be changed to:

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

JUSTIFICATION FOR THE PROPOSED CHANGE: The annual emergency diesel generator maintenance inspection represents a significant contribution to total diesel generator unavailability. The proposed change will extend the intervals between diesel generator outages which are required to support maintenance inspections and thereby improve emergency diesel generator availability. The original vendor recommendations for annual inspections were based upon service applications for locomotives rather than for service as a standby power supply for a nuclear plant. The vendor has reviewed .his original recommendations, operating demands of nuclear power plant standby service and the EMD-MKW Owners Group Maintenance document and has concurred with the Owners Group recommendation to a longer maintenance inspection interval.

ENCLOSURE 2 (CoNTZNUED)

Page 2 of 2 Inspections performed on the diesel generators, including recent annual, two year, three year, and six year inspections, have revealed no significant wear on any of the diesel parts required to be inspected annually.

This Technical Specification revision is also supported by the fact that several plants of the same type (BWR-4) and vintage as BFN also utilize EMD diesels and have different Technical Specification requirements concerning diesel maintenance intervals. Most notably was the recent amendment to Toledo Edison's Davis-Besse Nuclear Power Station's Technical Specification which extended the 18 month diesel generator inspection during shutdown to a maximum inspection interval not to exceed 30 months. Davis-Besse uses the same type diesels used at BFN, EMD 20-645-E4 engines.

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ENCLOSURE 3 BROMNS FERRY NUCLEAR PLANT (BFN)

UNITS 1, 2, AND 3 (TVA BFN TECHNICAL SPECIFICATION NO. 332)

P OP ED 0 SIG IFICA T HAZARDS CO SIDERATIO S DETERMI ATIO DESCRIPTION OF THE PROPOSED TECHNICAL SPECIFICATION CHANGE: The proposed change applies to Units 1, 2, and 3 ~ The change modifies Surveillance Requirement 4.9.A.l.d which currently requires that each diesel generator shall be given an annual inspection in accordance with instructions based on the manufacturer's recommendations. The proposed change revises the interval between maintenance inspections to 24 months.

BASES FO PROPOSED NO SIGNIFICANT HAZARDS CONSIDERATION DETERMINATION The NRC has provided standards for determining whether a significant hazards consideration exists as stated in 10 CFR 50.91(c). A proposed amendment to an operating license involves no significant hazards considerations 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 an accident previously evaluated, or (3) involve a significant reduction in a margin of safety. The proposed TS change is judged to involve no significant hazards considerations based on the following;

1. The proposed amendment does not involve a significant increase in the probability or consequence of any accident previously evaluated.

The proposed surveillance interval has been determined by the manufacturer to be adequate to detect wear prior to any significant reduction in either capability or availability of the emergency diesel generators; therefore, the accident mitigation capability of the plant has not been adversely affected, Emergency diesel generator availability is expected to increase as a result of reduced outage time. Other surveillances which are specifically related to emergency diesel generator capability are not being changed. The accident mitigation capability of plant features is not reduced and the proposed amendment does not cause or allow the reactor plant to be operated under different conditions than currently licensed.

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ENCLOSURE 3 (CONTTNUEn)

Page 2 of 2 Therefore, the proposed amendment does not involve a significant increase in the probability or consequences of an accident which has been previously evaluated.

2 ~ The proposed amendment does not create the possibility of a new or different, kind of accident from any previously evaluated. The proposed amendment does not create or cause any new modes of operation. External conditions required for operations are not changed by the amendment.

Therefore, the proposed amendment does not create the possibility of a new or different kind of accident from any accident previously evaluated.

3. The proposed amendment does not involve a significant reduction in the margin of safety. The wear, corrosion and aging acceptance criteria associated with diesel generator inspection are not being changed, The reduction in the ability to detect wear has been evaluated by the manufacturer to be insignificant because the wear rate is small relative to the inspection interval under normal nuclear plant standby service.

The availability of the diesel generators is expected to improve because of a reduction in maintenance outage time. For the above reasons, the capability and availability of the diesel generators to perform protective actions is not significantly reduced. Since the diesel generators remain capable of performing protective actions when required and before any plant parameters approach safety margins, the proposed amendment does not change any accident or transient analyses which has been used as a plant licensing basis. Therefore, the proposed amendment does not involve a significant reduction in a margin of safety.

CONCLUSION TVA has evaluated the proposed amendment described above against the criteria given in 10 CFR 50.92(c) in accordance with the requirements of 10 CFR 50 '1(a)(1). This evaluation has determined that the proposed amendment will

~o (1) involve a significant increase in the probability or consequences of an accident previously evaluated, (2) create the possibility for a new or different kind of accident from any accident previously evaluated, or (3) involve a significant reduction in a margin of safety, Thus, TVA has concluded that the proposed amendment does not involve a significant hazards consideration.

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