ML20006C151
| ML20006C151 | |
| Person / Time | |
|---|---|
| Site: | Prairie Island  |
| Issue date: | 01/31/1990 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML20006C147 | List: |
| References | |
| NUDOCS 9002060388 | |
| Download: ML20006C151 (6) | |
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e SAFETY EVALUATION REPORT BY THE OFFICE OF NUCLEAR REACTOR REGULATION PRAIRIE ISLAND NUCLEAR GENERATING PLANT, UNIT NOS. 1 AND 2 RELATED TO THE EMERGENCY DIESEL GENERATORS Q_UALIFICATION PLAN
1.0 INTRODUCTION
The following is the staff evaluation of the proposed qualification plan for new emergency diesel generators (EDG) to be installed by Northern St,ntes Power (NSP) at Prairie Island Nuclear Generating Plant (Prairie Island).
NSP is planning to add two additional EDG; the plant presently has two EDG shared by the two units.
The purpose of adding two EDG to Prairie Island is to provide dedicated redundant emergency power sources for both Unit 1 and Unit 2 of sufficient margin to meet possible future load expansion.
The two additional EDG will provide emergency power for Unit 2 while the existing two EDG will service Unit No. 1.
The new EDG, rated at 5400kW continuous with a capability of 110 percent overload or 5940kW for 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> (in any 24 hour2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> period), 1200 RPM, 4160V AC, and 0.8 power factor, will be manufactured by the French firm, Societe Alsacienne de Construc-tion Mecaniques de Mulhouse (SACM).
Each EDG set is a tandem unit using two SACM model 0045, 16 cylinder engines coupled with a single generator manufactured by Jeumont-Schneider of France.
NSP submitted in Appendix 1 to their letter of September 29, 1989 (Reference 1), a description of the diesel generators and their support systems: air start, engine cooling water, fuel oil, lube oil, combustion air and exhaust systems.
An auxiliary " desk" or skid for each unit contains the local metering, prelube system, filtration, and " keep warm" water heater components.
NSP will use-a computer driven non-1E monitoring system to provide the following functions:
1.
General surveillance and local alarm.
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Trending based on stored data to allow accurate prediction of the need for preventive maintenance.
This monitoring system is supplemental, not redundant,-to either the diesel generator annunciator system or the information provided to the Emergency Response Computer System.
NSP, by letter dated September 29, 1989, submitted a qualification plan for the SACM EDG Model UD45.
The staff reviewed this plan and raisea few concerns and reauested claH fications to nine items which the licensee did not address in his-submittal of September 29, 1989.
These concerns were discussed with NSP
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7 representative by the Project Manager, Mr. D. Dilanni, in a meeting in Region III on December 14, 1989, and by the staff in several phone conversations.
NSP submitted additional information, clarifications, and data in their letter dated l
December 15,1989, (Reference 2) addressing these items.
The staff has evaluated NSP submittals and our findings are reported below.
i
2.0 EVALUATION
The staff evaluation is based on NSP's letters dated September 29, 1989, and December 15, 1989, their attachments, and several phone discussions.
'These items are related to (a) seismic qualification, (b) aging requirements, (c) the environment in which the equipment will be operated, (d) restarting the EDG from a hot engine condition, (e) results of the review of the QA program, (f) the reliability of the units, (g) the improvements and increase in reli-i ability, (h) the length of an overloading test, and (i) the limits of torsional vibration of the units.
Proposed qualification plan of the EDG is based on a combination of testing, engineering analysis, functional testing performed both at the vendor facilities, and in the field prior to p1Leing the EDG in service for Unit 2 at Prairie Island.
The qualification testing results will confirm that the EDGs will mest the engineering design requirements of Prairie Island and are qualified for the-intended service.
The test (qualification) will be based on the requirements of IEEE Standard 387-1984, "IEEE Standard Criteria for Diesel Generator Units Applied as Standby Power Supplies for Nuclear Power Generating Stations," Regulatory Guide 1.9, Revision 2, " Selection, Design, and Qualification of Diesel Generator Unit Used as Standby (On-site) Electric Power Syst9m at Nuclear Power Plants," and Regulatory Guide 1.108 Revision 1, " Periodic Testing of Diesel Generator Units Used as Onsite Electric Power Systems at Nuclear Power Plants."
NSP committed to perform factory and on-site testing to qualify the EDG units.
A.
Factory Testing 1.
Load Capability Tests 4
Each unit will be tested to demonstrate the capability of the EDG to carry the loads as follows:
a.
Light or no load test till the engine oil and water system temperature is stabilized plus I hour.
b.
Rated continuous nameplate load (100%) for 22 hours2.546296e-4 days <br />0.00611 hours <br />3.637566e-5 weeks <br />8.371e-6 months <br /> continuous operation.
c.
Short time overload (110%) operation for 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> continuous.
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In addition, a short time rated lo6d rejection test will be performed to verify that the engine overspeed performance characteristics are acceptable.
2.
Start and Load Acceptance Tests Series of tests will be conducted to establish the capability of the unit to start, accept loads within the specified periods of time, and be loaded to meet the requirements of the plant design.
Each EDG will be subjected to one simulated loading sequence based on Prairie Island 1:4d values.
A combination of motor and resistive loads will be used wfth the voltage, frequency,.and load values monitored.
The simulated step loading will be carried up to 5400kW which is the generator rating.
Also, a loss of 100 percent load will be initiated and both voltage and frequency will be monitored to confirm that-the unit meets Prairie Island parameters.
NSP requested that the " fast start" testing of the EDG be 35 times without a failure instead of the 300 " fast starts".as stated in Sub-section 7.2.2 of IEEE 387.
The 35 starts will be at " keep warm" standby temperatures, accelerate to design frequency and voltage in less than or equal to 10 seconds, and application of a step load of 50% of the continuous rating held for a period of time to reach the engine equilibrium condition.
To justify limiting the number of tests to 35 starts NSP submitted in the attachments to their letters of September 29, 1989, and December 15, 1989, technical data, information, references, test results, and test reports of similar units tested at the factory and different sites.
These tests and their results are summarized as follows:
a.
At Krummel Nuclear plant in West Germany one model UD45 unit was tested for start and load acceptance.
The tests included 600 successful start and load cycles without a failure.
l b.
At EdF Cruas nuclear plant in France using one EDG UD45 model, same as the one to be supplied to Prairie Island, was tested for start and load acceptance.
The tests included 1500 successful starts without failure.
c.
The ASCO nuclear plant in Spain is equipped with 4 diesel generator sets using SACM model UD45 diesels.
These units were tested at the factory and at the site successfully.
At the site 35,. valid tests were successfully completed with a total of 140 start-load cycles for the four units without
- a. failure.
Based on the above tests, the satisfactory results, and the data and documentation submitted, the staff concluded that these tests confirmed a high level of reliability of these units.
Testing each unit 35 times as requested by NSP's letter of September 30,1989, is justified and is acceptaM e.
No extensive 300 tests are necessary to establish the reliability of SACM model UD45 which will.be installed at Prairie Island.
i 3.
Marain Tests i
t The purpose of the margin test is to demonstrate that the EDG capa-I bility to start and carry loads that are greater than the magnitude' of the most. severe step load. Two margin tests will be performed and a total load value equal to the largest single sequenced load plus 10 percent will be used.
A loss of-largest load will be initiated with the voltage and the frequency monitored during the transient.
The staff has reviewed the load capability, the start.and load l
acceptance, and the margin tests. programs at the factory and find them acceptable as they will verify the capacity, the capability, and the reliability of the units.
B.
Site Testing The test of the EDG at the site after installation will use R.G.1.108 i
sections C.2.a.1 through C.2.a.9 as guidelines to verify in-situ per-formance of the EDG and its associated support systems.
1.
Component Prerequisite Testino This testing is to verify the proper operation of the controls, set i
points, and initial operation of various-components.
i 2.
Pre-Op Testing Each unit will be tested to demonstrate and confirm proper cperation of the following systems: Controls, interlocks, alarms and monitoring systems and various support systems such as starting air, " keep warm",
and lube oil systems.
Each EDG starting, loading capabilities and reliability will be demonstrated by the following tests:
Using the actual EDGs installed at Prairie Island a repeat of l
a.
the manufacturer 24 hour2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> load testing will be performed to' verify the continuous operation of each unit.
Following the 24 hour2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> run, loss of short time load (110%) will be verified.
b.
A Valid 35 consecutive in-situ start demands followed by loading
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the EDG to greater than 50 percent of continuous rating for at least one hour without failures will be performed on each unit.
3.
Integrated Safeguards Pre-op Testing Simulated loss of off-site power (LOOP), safety injection, and the combination of LOOP and safety injection demand using the actual plant loads and the safeguard sequencer as final ~ tests to demonstrate the response of the units.
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I The staff has concluded that the site testing is acceptable as it meets-the intent of the above mentioned regulations and standards.
NSP in their letter of December 15, 1989, responded to the nine concerns raised by the staff as follows:
a.
Seismic Qualification NSP confirmed that the EDG will meet the seismic qualification requirements of Prairie Island.
This qualification will be by j
testing, analysis, or by combination of testing and analysis meeting the requirements of IEEE-344 and NRC R.G. 1.100.
b.
Aoino Classification NSP will follow the aging requirement of IEEE 387-1984 section 7-3.
The components and assemblies will be classified and qualified before placing the units in service.
j c.
Environment 1
NSP confirmed that the units and system components will-be supplied to meet the requirements of the ambient room tempera-l tures and humidity when tne units are installed.
d.
Hot Restart j
The " Hot Engine" restart capability will be a part of the Inte-grated Safeguards Pre-Operational Test program as discussed above.
l l.
e.
QA Program l
NSP confirmed that the QA program will meet the criteria of 10 I
CFR Part 50, Appendix B.
l f.
Reliability l
Based on the tests performed at European installations, number i
of tests without failure, the calculated reliability is 1.0 (zero failures on 600, and 1500 tests).
g.
Improvement on Reliability i
Two modifications were made on the UD45 units.
The rigorous 1500 tests without failure confirmed the effectiveness.of the l
modificctions.
h.
Length of Overload Test l
A value of 146% of the generator full load nameplate was carried L
for 1.5 seconds during a factory simulation of step loading.
i 6-i which was done during the final stage of the loadit,g sequence.
j This confirmed the capacity and response of the generator.
i.
Torsional Vibration 1
The vendor, SACM, carried out the necessary' torsional vibrations calculation and verified that no harmful torsional vibration occurs, thus meeting the requirements of IEEE 387-1984, l
paregraph 5.5.1.2.
The above responses answer and clarify satisfactorily the concerns I
of the staff.
3.0 CONCLUSION
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Based on the evaluation discussed above, the staff concurs that the programs to i
test the EDG at the manufacturer's facilities and in-situ will provide significant assurances that the units will meet the intent of the regulations and the engineering design requirements (capacity, capability, and reliability).
4.0 REFERENCES
i 1.
Letter from Thomas M. Parker, Manager, Nuclear Support Services, Northern States Power Company.
to Document Control Desk, dated September 29, 1989.
2.
Letter from Thomas M. Parker, Manager, I
Nuclear Support Services, Northern States Power Company to Document Control Desk, dated December 15, 1989.
Principal Contributor:
Dr. S. N. Saba Date: Jenuary 31, 1990 i
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