ML17258A944

SEP Technical Evaluation:Topic VIII-2,Diesel Generators, Final Draft

ML17258A944
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Site:	Ginna
Issue date:	03/03/1981
From:	Office of Nuclear Reactor Regulation
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References
TASK-07-02, TASK-7-2, TASK-RR 0044J, 44J, NUDOCS 8104080467
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Text

0044J SEP TECHNICAL EVALUATION

-TOPIC VIII-2 DIESEL GENERATORS FINAL DRAFT ROBERT EMMETT GINNA UNIT NO.

1 Docket No. 50-244 March 1981 3-3-81

CONTENTS

1.0 INTRODUCTION

2.0 CRITERIA 1

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2 2.1 Diesel Generator Loading 2.2 Bypass of Protective Trips 2.3 Diesel Generator Testing

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2 3.0 DISCUSSION AND EVALUATION

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6 3.1 Diesel Generator Loading 3.2 Bypass of Protective Trips 3.3 Diesel Generator Testing

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SUMMARY

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REFERENCES

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SEP TECHNICAL EVALUATION TOPIC VIII-2 DIESEL GENERATORS ROBERT EMMETT GINNA UNIT NO.

1

1.0 INTRODUCTION

The objective of the review is to determine if the onsite AC generator for the R.

E. Ginna Nuclear Station has sufficient capacity and capability to supply the required automatic safety loads during anticipated occurrences and/or in tne event of postulated accidents after loss qf offsite power.

The requirement that the onsite electric power supplies have capacity and capability to complete the required safety functions is contained in General Design Criterion 17.

Criterion III, "Design Control," of Appendix B, "Quality Assurance Criteria for Nuclear Power Plants and Fuel Reprocessing Plants," to 10 CFR Part 50 includes a requirement that measures be provided for verifying or checking the adequacy of design by design reviews, by the use of alternate or simplified calculational

methods, or by the performance of a suitable testing program.

Regulatory Guides, IEEE Standards, and Branch Technical Positions which provide a basis acceptable to the NRC staff for compliance with GDC17 and Criterion III include.

Regulatory Guide 1.9, "Selection of Diesel Generator Set Capacity for Standby Power Supplies;" Regulatory Guide 1.108, "Periodic Testing of Diesel Generators Used as Onsite Power Systems at Nuclear Power Plants";

IEEE Standard 387-1977, "Criteria for Diesel-Generator Units Applied as Standby Power Supplies for Nuclear Power Sta-tions;" BTP ICSB2, "Diesel-Generator Reliability Qualification Testing"'nd BTP ICSB17, "Diesel Generator Protective Trip Circuit Bypasses."

Specifically, this review evaluates the loading of the diesel-generator, bypasses of protective trips during accident conditions and periodic testing.

The SEP reviews for Topics III-1 and III-12 will evaluate the diesel-generator qualification.

2. 0 CRITERIA 2'iesel Generator Loadin Regulatory Guide 1.9, "Selection of DieselWenerator Set Capacity for Standby Power Supplies," provides the basis acceptable to the NRC staff for loading diesel-generator units.

The following criterion is us'ed in this report to determine compliance with current licensing requirements:

(1)

The automatically-connected loads on each diesel-generator uni should not exceed the 2000-hour rating.

(Loads must be conservatively estimated utilizing the nameplate ratings of motors and transformers with motor efficiencies of 90% or less.

When available, actual measured loads can be used.)

2.2 B

ass of Protective Tri s.

Branch Technical Position (BTP)

ICSB 17, "Diesel-Generator Protective Trip Circuit Bypasses,"

specifies that:

(1)

The design of standby diesel generator systems should retain only the engine overspeed and the generator differential trips and bypass all other trips under an accident condition (2) If other trips, in addition to the engine overspeed and generator differential, are retained for accident con-

ditions, an acceptable design should provide two or more independent measurements of each of these trip parameters.

Trip logic should be such that diesel-generator trip would require specific coincident logic.

2.3 Diesel Generator Testin Regulatory Guide 1.108, "Periodic Tesing Of Diesel Generator Units Used as Onsite Electrical Power Systems at Nuclear Power Plants",

states that:

(1)

Testing of diesel-generator units, at least once every 18 months, should:

(a)

Demonstrate proper startup operation by simulating loss of all ac voltage and demonstrate that the diesel generator unit can start automatically and attain the required voltage and frequency within acceptable limits and time.

(b)

Demonstrate proper operation for design-accident-loading sequence to design-load requirements and verify that voltage and frequency are maintained within required limits.

(c)

Demonstrate full-load-carrying capability 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 />, of which 22 hours2.546296e-4 days <br />0.00611 hours <br />3.637566e-5 weeks <br />8.371e-6 months <br /> should be at a load equivalent to the continuous rating of the diesel generator and 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> at a load equivalent to the 2-hour rating of the diesel generator.

Verify that voltage and frequency requirements are maintained.

The test should also verify that the cooling system func-tions within design limits.

(d)

Demonstrate proper operation during diesel-generator load shedding, including a test of the loss of the largest single load and of complete loss of load, and verify that the voltage require-ments are met and that the overspeed limits are not exceeded.

(e)

Demonstrate functional capability at full-load temperature conditions by rerunning the test phase outlined in (a) and (b), immediately following (c), above.

(f)

Demonstrate the ability to synchronize the diesel generator unit with offsite power while the unit is connected to the emergency load, transfer this load to the offsite power, isolate the diesel-generator unit, and restore it to standby status.

(g)

Demonstrate that the engine will perform properly if switching from one fuel-oil supply system to another is a part of the normal operating proced-ure to satisfy the 7-day storage requirement.

(h)

Demonstrate that the capability of the diesel-generator unit to supply emergency power within the required time is not impaired during periodic testing under (3), below.

(2)

Testing of redundant diesel-generator units during normal plant operation should be performed indepen-dently (nonconcurrently) to minimize common failure modes resulting from undetected interdependences among diesel-generator units.

However, during reliability demonstration of diesel-generator units during plant preoperational testing and testing subsequent to any plant modification where diesel-generator unit inter-dependence may have been affected or every 10 years (during a plant shutdown),

whichever is the shorter, a

test should be conducted in which redundant units are started simultaneously to help identify certain common failure modes undetected in single diesel-generator unit tests.

(3)

Periodic testing of diesel-generator units during nor-mal plant operation should:

(a)

Demonstrate proper startup and verify that the required voltage and frequency are automatically

attained within acceptable limits and time.

This test should also verify that the components of the diesel-generator unit required for automatic startup are operable.

(b)

Demonstrate full-load-carrying capability (contin-uous rating) for an interval of not less than one hour.

The test should also verify that the cooling system functions within design limits.

This test could be accomplished by synchronizing the generator with the offsite power and assuming a load at the maximum practical rate.

(4)

The interval for periodic testing under (3),

above (on a per diesel-generator unit basis) should be no more than 31 days and should depend on demonstrated perfor-mance.

If more than one failure has occurred in the last 100 tests (on a per nuclear unit basis),

the test interval should be shortened in accordance with the following schedule:

(a) If the number of failures in the last 100 valid tests is one or zero, the test interval should be not more than 31 days.

(b) If the number of failures in the last 100 valid tests is two, the test interval should be not more than 14 days.

(c)

Tf the number of failures in the last 100 valid tests is three, the test interval shoul'd be not more than 7 days.

(d) If the number of failures in the last 100 valid tests is four or more, the test interval should be not more than 3 days.

3.0 DISCUSSION AND EVALUATION Since both diesel generators'orst-case loads, protective trips, and trip bypasses are identical, a review of one serves as a review of both.

3.1 Diesel-Generator Loadin Discussion.

On November 22,

1978, RG6E provided a current list of loads automaticall connected to the diesel generators in the event of a LOCA concurrent with a loss of offsite power (Reference 1).

Discussion with the licensee (Reference

2) established that the KW load values listed in Table 8.2-1 of the FSAR (Reference

3) are measured

values, so it is not necessary to use the 90X motor efficiency in conversion of HP to KW.

The maximum step load change is 539 KW (28X of continuous capacity) which occurs 15 seconds after the diesel generator start signal.

Evaluation.

Ginna Technical Specifications require a test of the diesel response to an emergency start signal during each refueling outage, but do not require the generators to assume emergency loads (Reference 4).

The maximum automatically connected load to either generator is 1995 KW which occurs during the injection phase of the LOCA response.

The maximum long-term automatically connected load is 1517 KW.

The diesel generators are rated at 2300 KW for 30 minutes, 2250 KW for two hours, and 1950 KW continuous.

Therefore, the total automatically connected load (at 87X of 30-minute capacity and 78% of continuous capacity) is within the criteria of Regulatory Guide 1.9.

3.2 B

ass of Protective Tri s Discussion.

On May 19,

1977, RGEE provided a list of protec-tive trips which render the diesel generators incapable of responding to an automatic emergency start signal (Reference 5).

The protective trips which are not bypassed under emergency conditions are low lubricating oil pressure and overspeed.

The low oil pressure trip uses three sensors and two out of three logic.

Evaluation.

The only protective trips which are not bypassed under emergency conditions are overspeed and low lubricating oil pres-

sure, and the low oil pressure uses redundant sensors and coincident logic.

Therefore, the diesel generator protective trips meet the re-quirements of BTP ICSB17.

3.3 Diesel Generator Testin Discussion.

Ginna Technical Specifications, paragraph 4.6.1, require diesel-generator testing as follows:

(1)

Manually-initiated start of the diesel generator, followed by manual synchronization with other power sources and assumption of load by the diesel generator up to the name-plate rating.

This test shall be conducted monthly on each diesel generator.

Normal plant operation will not be affected.

(2)

Automatic start of each diesel generator and automatic restoration of particular vital equipment, initiated by an actual loss of all normal AC station service power supplies together with a simulated safety injection signal.

This test shall be conducted during each refueling shutdown to assure that the diesel-generator will start and following maximum breaker closure times after the initial starting signal for trains A and B

will not be exceeded.

Diesel plus Safety Injection Pump 20 sec..

22 sec.

plus RHR Pump All breakers closed 40 sec.

42 sec.

(3)

Each diesel generator shall be given a thorough inspection at least annually following the manufacturer's recommendations for this class of standby service.

The above tests will be considered satisfactory if all applicable equipment operates as designed.

(4)

Diesel generator electric loads shall be not increased beyond the long-term rating of 1950 KW.

Evaluation.

Diesel-generator testing defined in the plant Technical Specifications address the criteria listed in paragraph 2.3 to the following extent:

(l)(a)

Voltage and frequency not specified (b)

Voltage and frequency not specified (c)

Duration not specified; load is limited to less than short-term automatically connected load (d)

Not addressed (e)

Not addressed (f)

Not addressed (g)

Not applicable (h)

Not addressed (2)

Not addressed (3)(a)

Synchronization is manual; time limit is not specified

(b)

Duration is not specified; load is limited to less than short-term automatically connected load.

(4)

Not addressed.

The Technical Specifications do not meet current licensing criteria for diesel-generator testing.

Diesel-generator failure data will be extracted by NRC from Licensee Event Reports and will be considered in the final evaluation of testing adequacy.

4.0

SUMMARY

Automatic diesel generator loading is in compliance with current licensing criteria.

The bypass of diesel generator protective trips is in agreement with current NRC staff guidelines.

Diesel-generator

testing, as specified by plant Technical Specifications, does not meet current licensing criteria.

The review of qualification of the diesel generators will be completed with SEP Topics III-6, Seismic Qualification, and III-12, Environmental Qualification.

5. 0 REFERENCES 1.

Letter RGGG (White) to NRC (Ziemann) dated November 22, 1978.

2.

Final Safet Anal sis Re ort, updated but no date given (Table 8.2-1 is dated January 1969).

3.

Telephone conversation RGGE (P. Wilkens) and EGSG Idaho, Inc.

(F. Farmer),

May 2, 1979.

Technical S ecifications (Chan e No. 6) for R. E. Ginna Nuclear Power Plant Unit No. 1, paragraph 4.6.l.b.

issued March 1, 1972.

5.

Letter RG&E (White) to NRC (Schwencer) dated May 19, 1977.

6.

General Design Criterion 17, "Electric Power System," of Appendix A, "General Design Criteria of Nuclear Power Plants," to 10 CRF Part 50, "Domestic Licensing of Production and Utilization Facilities."

7.

General Design Criterion III, "Design Control," of Appendix B, "Quality Assurance Criteria for Nuclear Power Plants and Fuel Reprocessing Plants,"

to 10 CRF Part 50, "Domestic Licensing of Production and Utilization Facilities."

8.

"Standard Criteria for Class IE Power Systems and Nuclear Power Generating Stations,"

IEEE Std.

308, 1974, paragraph 5.2.4.

9.

"Criteria for Diesel-Generator Units Applied as Standby Power Supplies for Nuclear Power Stations,"

IEEE Std.

387, 1977.

10.

"Selection of Diesel Generator Set Capacity for Standby Power Supplies," Regulatory Guide 1.9.

ll.

"Periodic Testing of Diesel Generators Used as Onsite Power Systems at Nuclear Plants," Regulatory Guide 1.108.

12.

Letter RGGE (Maier) to NRC (Crutchfield), dated January 30, 1981.

13.

"DieselWenerator Reliability Qualification Testing",

BTP ICSB2 (PSB).

14.

"Diesel-Generator Protective Trip Circuit Bypasses,"

BPT ICSB17 (PSB).

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