ML20246L827
| ML20246L827 | |
| Person / Time | |
|---|---|
| Site: | Hatch  |
| Issue date: | 07/11/1989 |
| From: | Hairston W GEORGIA POWER CO. |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| GL-88-14, HL-640, NUDOCS 8907190007 | |
| Download: ML20246L827 (8) | |
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04930 Ju?y 11, 1989 U.S. Nuclear Regulatory Commission ATTN: Document Control Desk Hashington, D.C.
20555 PLANT HATCH - UNITS 1, 2 NRC DOCKETS 50-321, 50-366 OPERATING LICENSES OPR-57, NPF-5 GENERIC LETTER 88 INSTRUMENT AIR SUPPLY SYSTEM PROBLEMS AFFECTING SAFETY-RELATED EOUIPME_N_I Gentlemen:
In Georgia Power Company's (GPC) initial response to Generic Letter 88-14, dated February 10, 1989, a commitment was made to send a subsequent report that would include the results of additional engineering review and research.
The attached enclosure summarizes our work related to Generic Letter 88-14 and closes the commitment mentioned above.
All reviews and/or investigations to date substantiate our original conclusion that the design, installation, testing, operation and maintenance of the instrument air systems at Hatch Nuclear Plant are adequate to ensure the proper and reliable operation of pneumatically operated, safety-related equipment.
Actions remaining for closure of this issue at Plant Hatch are:
1.) Testing of safety-related, air operated components and accumulators that are not currently tested under our regular surveillance program for correct failure position upon loss of instrument air and: 2.) Verification of the seismic support of nine accumulators located inside containment.
This remaining scope is detailed in the attached enclo:ure.
8907190007 890711 DR ADOCK 05000321 p
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I U.S. Nuclear Regulatory Commission July 11, 1989' Page Two Should you have any questions, please advise..
Mr. H. G. Hairston, III states that he is a Senior Vice President of E
Georgia Power Company and 8.s authorized to execute this oath on behalf of Georaia Power Company and that, to the best of his knowledge and belief, the facts set forth in this letter and enclosures are true.
GEORGIA POWER COMPANY By: M
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H. G. Hairtton,.III Senior Vice President Nuclear Operations Sworn to and subscribed before me this //
day of Ordu 1989.
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N EMES DEC.15.1992 DLM/dm
Enclosure:
Georgia Power Company Supplemental Response to Generic Letter (G. L.) 88-14 c: Georaia Power Cormany -
Mr. H. C. Nix, General Manager - Nuclear Plant Mr. J. D. Heidt, Manager Engineering and L'. censing - Hatch GO-NORMS U.S. Nuclear Reaulatory Commission. Hashinaton. D.C.
Mr. L. P. Crocker, Licensing Project Manager - Hatch U.S. Nuclear Reaulatory Commission. Reaion Il Mr. S. D. Ebneter, Regional Administrator Mr. J. E. Menning, Senior Resident Inspector - Hatch
ENCLOSURE 1 GEORGIA POWER COMPANY SUPPLEMENTAL RESPONSE TO GENERIC LETTER (G. L.) 88-14 I - G. L. Item 1: Verification by test that actual instrument air quality is consistent with the manufacturer's recommendations for individual components served.
A.
Action Plan:
1.
Select representative sample points for the instrument air system (s) at Plant Hatch.
2.
Conduct in-plant testing to measure actual air quality.
3.
Compare in-plant results with component requirements.
B.
Status:
To determine the recommended air quality requirements for air
- operated, safety-related components, a
review of vendor documents, specifications, and manuals was conducted.
Vendors were also contacted directly to obtain the required air quality for their supplied components.
The results of this review indicated that no vendor, with the exception of General Electric (GE), had a quantitative definition of " clean, dry, and oil free" air for use in their air-operated equipment, and no technical basis or specific engineering recommendations relative to air quality was provided. GE has requirements for filtered, oil free air with a dewpoint of -40*F at 100 psig.
This requirement is predicated on certain air quality at the component served by the air system.
GE was provided with the results of the air quality testing performed at Plant Hatch.
Per their review, the current air quality is satisfactory for G. E. supplied equipment.
The ANSI standard MC 11.1-1976, " Quality Standard for Instrument Air",
establishes instrument air quality limits to preclude malfunctions of equipment supplied by the air systems.
Although Plant Hatch is not committed to meeting the requirements of this standard, it was selected for use as a guideline because of its reference in Section 3.2 of NUREG-1275, Reguiatory Guide 1.68.3, and SRP 9.3.1.
Actual air samplir.g has been performed at various locations in the Instrument Air System, In each case, the requirements of ANSI MC ll.) %ve been satisfied. Since the sampled air has been analyzed and successfully compared against the established industry standard for Instrument Air quality, it is concluded that the Instrument Air System at Plant Hatch satisfies all vendor requirements for motive gas quality.
04930 HL-640 El-1
Other air systems included in our Generic Letter review were the Drywell Pneumatic System and the Diesel Generator Air Start (DGAS) System.
These systems have not been tested and the results compared to the guidelines of ANSI MC 11.1.
The Drywell Pneumatic System receives motive gas from a liquid nitrogen storage tank.
Although this system has not been tested, the quality of the gas is expected to easily exceed the ANSI requirements because of the manufacturers' standard on quality nitrogen production.
The DGAS System receives motive gas from independent compressor / receiver assemblies.
Unlike the Instrument Air System, the DGAS system is not equipped with dryer assemblies.
The compressors charge the air receivers which directly feed the diesels' air start system.
Although this system has not been tested, the quality of gas is expected to meet the ANSI guidance for particulate. Per the vendor there are no requirements relative to dew point or hydrocarbon parameters.
The system was provided by the diesel vendor and maintained per the diesel vendor guidelines; therefore, the vendor air quality requirements are inherently satisfied.
These systems will be tested and the rer, ult ! compared to the guidelines of ANSI MC 11.1 by December 1989.
Any data that does not meet the criteria, with the exceptica of dew point and hydrocarbon ?evels for the DGAS System, will be evaluated for i
acceptability.
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II - G. L. Item 2: Verification that maintenance practices, emergency procedures, and training are adequate to ensure that safety-related equipment will function as intended on q
loss of instrument air.
A.
Action Plan 1.
Evaluate current maintenance programs and practices to determine overall adequacy for ensuring the availability and reliability of components within the scope of the Geaeric Letter.
2.
Review plant procedures designed to mitigate the effects of a loss of instrument air.
i 3.
Review the content and scope of the operator training programs for adequacy in the area of required response to a loss of instrument air.
04930 HL-640 El-2
B.
Status:
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.. The initia.1 response addressed items 2 and 3 above.
The current maintenance programs and practices were evaluated by.
performing a review of the maintenance and failure history of safety-related, air-operated components in conjunction ~ with the review of component specific surveillance procedures.
This review determined that the current maintenance practices, in combination with the periodic testing of the safety-related, air operated components, do provide adequate _ assurance that the equipment would function as intended on loss of instrument air.
III. - G. L. Item 3: Verification that the design of the entire instrument air system including air. or other pneumatic accumulators is in accordance with its intended function, including verification by test that air-operated safety-related components will perform 'as expected in accordance with all design-basis events, including a loss of the normal instrument air system.
This design verification should include an analysis of current air operated component failure positions to verify that they are correct for assuring required safety functions.
A.
Action Plan:
1.
Identify, by reviewing plant design documentation, the system and component level safety design bases.
2.
Create a list of all. safety-related components within the scope of the generic letter.
3.
Review current operational and maintenance activities (e.g.,
preventive maintenance procedures, surveillance test procedures, etc.)
to verify that proper operation of components identified in the above list is proven periodically.
4.
Schedule any additional safety-related component testing required.
5.
Review / evaluate plant procedures for verifying the design function of all safety-related accumulators.
04930 HL-640 El-3 a
to B.
Status:
The initial' response addressed item 4 above.
Safety-related: components and equipment supplied by air systems at Plant Hatch and their design failure positions have-been identified.
In each case, the failure position of the given component was determined to be acceptable except for the following RHR and CS jockey pump suction valves:
1E21-F069A, B 1E21-F070A, B The loss of instrument air failure position for. these valves is closed.
The jockey pump system is a. standby system which is not normally considered. to be safety-related; however, th:. system does operate during accident conditions.
If the suction
. (1E21-F069A, B and IE21-F070A, B) were to fail closed due to the
' loss of air, there.was an accident that forced a significant delay. in starting the RHR and/or the Core Spray system, and the pump discharge check valves leaked significantly, then there is the possibility of a water hammer event occurring on system
' start.
Even though -this series of events is extremely unlikely, valves IE21-F069A, B and 1E21-F070A, B will be modified such that they fail open and their failure positions verified by functional test.
In the interim, GPC will modify the system operating procedure to require'the following, should instrument air be lost:
1.
Immediately secure the jockey pumps to avoid damaging them due to loss of suction.
2.
Open jockey pump suction from RHR isolation valves 1E21-F060A, B.
3.
Restart the jockey pumps once suction has been reestablished and vent the RHR/CS disc': 1rge lines as required.
To satisfy the requirement in Generic Letter item 3 " verification by test", Plant Hatch procedures were reviewed to locate existing procedures that regularly demonstrate operability of safety related components that use instrument air.
The review determined if the procedures suitably simulated loss of instrument air and verified proper operation of each safety-related component as defined in the Generic Letter.
Several components were identified that did not have procedures to regularly demonstrate their operability.
In general, the air operation of these components does not have to be regularly demonstrated for reasons such as the-air operation feature is for testing and is therefore not safety related, or the component is not moved from its safe position during normal or loss of air conditions.
For this type of air operation, it was determined that testing per G9neric Letter item 3 is not necessary.
04930 i
HL-640 El-4
The following components were found not to be included in surveillance procedures that would demonstrate failure in the correct safety position due to loss of air and did not fall into the group of components for which testing was determined to be unnecessary mentioned above:
1P41-'F208A 1Z41-F028A 1P41-F208B lZ41-F028B 1P41-F208C 2P41-F320A 1P41-F208D 2P41-F320B 1Z41-F009B 2P41-F320C lZ41-F010A
-2P41-F3200 1Z41-F010B These components will be added to the appropriate procedures to ensure the valves are regularly tested, thereby demonstrating their operability as required by the generic letter.
A review has been performed of the design basis of safety-related accumulators and receivers associated with the three air systems at Plant Hatch.
This review included sizing and seismic _ design.
The accumulators are seismically qualified and seismically supported.
This has been verified with the exception of the seismic support of accumulators 1821-A003K, L and 2B21-A003A, C, E, H, K, L, and H which are located inside the drywell and are inaccessible during plant operation.
This remaining verification will be performed during the next outage of sufficient duration.
With the exception noted above the design basis' of the safety-related accumulators at Plant Hatch has been verified as being in accordance'with its intended function.
The following safety-related accumulators are not included in the Hatch Nuclear Plant Inservice Inspection program and are not otherwise tested to prove their design criteria:
IPS2-A014 2P52-A004 1P52-A015 2P52-A013 1P52-A032
.2P52-A014 1P52-A033 2P52-A015 1P52-A034 2P52-A016 1P52-A035 2P52-A017 IP52-A036 2PS2-A018 2P52-A003 l
These accumulators are associated with the Hydrogen /0xygen
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Analyzer System and the Torus / Reactor Building Vacuum Breakers for units 1 and 2.
The accumulators will be tested within the next refueling outage scheduled for each Unit.
The next outages are tentatively scheduled for March 1990, Unit 1, and September 1989, Unit 2.
04930 HL-640 El-5
IV. - G. L. Item 4: Provide a discussion of the Plant Hatch program for maintaining proper instrument air quality.
A.
Action Plan:
Upon issuance of the final results of the work associated with the generic letter, Plant Hatch will review the instrument air quality program and make any improvements that are determined to be required.
B.
Status:
Upon completion of the air quality testing and verification by test of operation of safety related, air operated components, a description of the Plant Hatch program for maintaining proper instrument air quality will be provided.
The description of the program is tentatively scheduled to be completed by August 1, l
1990.
04930 HL-640 El-6 N ______ _ _