ML20246G135
| ML20246G135 | |
| Person / Time | |
|---|---|
| Issue date: | 01/23/1989 |
| From: | Advisory Committee on Reactor Safeguards |
| To: | Advisory Committee on Reactor Safeguards |
| References | |
| REF-GTECI-043, REF-GTECI-NI, TASK-043, TASK-43, TASK-OR ACRS-2617, AEOD-C701, GL-88-14, IEIN-87-028, IEIN-87-28, NUDOCS 8905150197 | |
| Download: ML20246G135 (48) | |
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SUMMARY
/ MINUTES OF THE ACRS SUBCOMMITTEE MEETING ON THE AUXILIARY AND SECONDARY SYSTEMS JANUARY 11, 1989 BETHESDA, MARYLAND INTRODUCTION
- The ACRS Subcommittee on Auxiliary and Secondary Systems held a meeting on Vednesday, January 11,1989, at 7920 Norfolk Avenue, Bethesda, Maryland, to discuss the problems associated with the air systems and the resolution of Generic Issue 43, " Air Systems Reliability." The entire meeting was open to public attendance. Mr. Sam Duraiswamy was the. cognizant ACRS Staff Engineer for this meeting. A list of documents submitted to the. Subcommittee is included in Attachment A, and a copy of the presentation' schedule is included in Attachment B.
ATTENDEES ACRS:
C. Michelson (Subcommittee Chairman), J. Carroll, C. P. Siess, and C. J. Wylie P. Wohld, ACRS Consultant Sam Duraiswamy (Cognizant ACRS Staff Engineer)
Principal Speakers:
NRC:
H. Ornstein, G. Burdick, and W. Lefave NRC Consultants:
E. Lofgren and B. Rothleder (Science Applications International Corporation (SAIC))
Toledo Edison Co.:
J. Hayes t
DESIGNATED ORIGINAL Certit$ ed By 890$150197 890123 PDR ACRS FDC 2617
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I Auxiliary & Secondary Systems Meeting Minutes January 11, 1989 EXECUTIVE SESSION Mr. Michelson, the Subcommittee Chairman, convened the meeting at 8:30 a.m. and stated that the purpose of the meeting was to hear presenta-tions by and hold discussions with representatives from the Office for Analysis and Evaluation of Operational Data (AE0D), Office of Nuclear Regulatory Research (RES), and Toledo Edison Company, as well as NRC Staff consultants with respect to the following:
- AE0D findings concerning the air systems malfunctions and its recommendations to alleviate this problem.
- Activities of the NRC Staff and the industry since the issuance of l
the AEOD report on air systems problems and the related Information Notice No. 87-28 " Air Systems Problems at U.S. Light Water Reac-tors," dated June 22, 1987.
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- Problems experienced by utilities with the air systems.
- Resolution of Generic Issue 43, " Air Systems Reliability."
Mr. Michelson stated that the Subcommittee had received neither written comments nor requests for time to make oral statements from members of the public.
AE0D STUDY ON AIR SYSTEMS PROBLEMS - DR. H. ORNSTEIN, AE0D Dr. Ornstein stated that AEOD performed a study to evaluate the actual operating experience and the vulnerability of safety-related equipment to common-mode failures associated with air systems. The AE0D findings and recommendations are contained in the report AE00/C701, " Air Systems Problems at U.S. Light Water Reactors," dated March 1987. Some of the AE00 findings are as follows:
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- Mismatched equipment - the air quality capability of the Instrument Air (IA) system filters and dryers do not always match the design requirements of the equipment using the air.
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- Maintenance of the IA system is not always performed in accordance with manufacturer's recommendations.
- Plant personnel do not understand the potential consequences of degraded air systems.
- Operators are not well trained to respond to losses of IA, and the emergency operating procedures for such events are frequently inadequate.
- The size and seismic capability of safety-related hacAup accumula-tors at several plants have been found to be inadequate.
Some of the recommendations of the AE0D to alleviate the problems associated with air systems are as follows:
- Ensure that air system quality meets the requirements specified by the manufacturers of the air-operated equipment.
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- Ensure adequate operator response by formulating and implementing anticipated transient and system recovery procedures for loss-of-
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air events.
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- Improve training to ensure that plant operators and maintenance personnel are sensitized to the importance of air systems and the vulnerability of safety-related equipment served by the air systems to common-mode failures.
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- Confirm the adequacy and reliability of safety-related backup accumulators.
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- Verify equipment response to gradual losses of air to ensure that such losses do not result in events which fall outside FSAR analy-ses.
Dr. Ornstein stategl that subsequent to the completion of the AEOD study, Information Notice No. 87-28, " Air Systems Problems at U.S. Light Water Reactors," dated June 22, 1987 was issued to all licensees to alert them to the potentially significant problems pertaining to air systems at light water reactors. Since the issuance of this Information Notice, similar events or design deficiencies:: have been observed to be occurring with a frequency of about one per month. These more recent events and the AEOD report C701 are included in NUREG-1275, Volume 2, " Operating Experience Feedback Report - Air Systems Problems," dated December 1987.
This document was transmitted to all licensees and applicants through Supplement 1 to Information Notice 87-28, dated December 28, 1987.
The NRC Staff was concerned about the rate of continuing occurrences and the sefety significance of the additional events related to air systems.
Consequently, Generic Letter 88-14, " Instrument Air Supply System Problems Affecting Safety-Related Equipment," dated August 8, 1988 was issued to all holders of operating licenses or construction permits.
The purpose of this Generic Letter is to request that each licensee /
applicant review NUREG-1275, Volume 2, and perform a design and opera-tions verification of the IA systems. This verification should include:
- Verification by test that actual IA quality is consistent with the j
manufacturer's recommendations for individual components served.
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- Verification that maintenance practices, emergency procedures, and training are adequate to ensure that safety-related equipment will function as intended on loss of IA.
- Verification that the design of the entire IA 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 In 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.
In addition to the above, each licensee / applicant should provide a discussion of their program for maintaining proper IA quality. The NRC j
Staff requires each licensee / applicant to provide a response to the Staff within 180 days that confirms that verification as described above has been performed.
Dr. Ornstein stated that although the NRC Staff has not received a lot of submittals from utilities responding to Generic Letter 88-14, he is aware that utilities are performing necessary work to meet the require-ments delineated in the Generic Letter. He mentioned that as a result of the AE00 recommendations included in its report that was sent to all licensees, Dresden Unit 2 had performed a gradual loss of IA system pressure test on all of its Main Steam Isolation Valves (MSIVs) and found that all MSIVs failed to close.
He said that this failure was due to design deficiency.
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Dr. Ornstein mentioned briefly some of the ongoing activities within the j
i NRC and industry related to air systems:
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- AE00 is performing a case study on solenoid valves associated with air systems.
- Brookhaven National Laboratory and SAIC have been performing some work for RES related to air systems.
- ANSI /ASPE are in the process of developing a Standard, " Performance Testing for Nuclear Power Plant Instrument Air Systems," which is expected to be issued in the near future.
- Institute of Nuclear Power Operations (INPO) has been looking at the problems associated with air systems, and had already issued two Significant Operating Event Reports (SOERs) on this matter.
Dr. Ornstein stated that the combined effects of Generic Letter 88-14, and other NRC and industry initiatives, are expected to improve the air systems reliability and minimize the problems associated with these systens in the future.
Mr. Michelson asked whether Generic Letter 88-14 requires that the licensees perform a gradual loss of air pressure test.
Dr. Ornstein responded that it does not explicitly require such a test. However, requirement 3 in the Generic Letter could be interpreted to be an inherent requirement for such tests.
Mr. Michelson requested copies of the two SOERs issued by INP0, St.
Lucie Plant inspection report, and Dresden Unit 2 LER related to the gradual loss of air pressure test.
Mr. Michelson asked whether the industry's efforts to improve the reliability of IA systems are as a result of the INP0 SOERs or because 1
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of the Information Notices and Generic Letter issued by the NRC. Dr.
Ornstein responded that based on his conversation with several util-ities, he believes that the efforts by industry are in response.to the-NRC Information Notices and Generic Letter.
Mr. Michelsen asked whether the effects of degraded voltage on air systems performance is being addressed by the ANSI /ASME Standard. Dr.
Ornstein stateci that it it not being specifically addressed.
Mr. Michelson asked whether they have looked at the effects of malfunc-tioning of the air-operated dampers in the Heating, Ventilating, and Air Conditioning (HVAC) systems.
Dr. Ornstein stated that this issue is mentioned in the AE00 report, but was not looked at in great detail.
Mr. Michelson asked whether AE00 has looked at the effects of the failures of regulators that regulate the air pressure to solenoid valves.
Dr. Ornstein stated that this issue is being looked into under the AEOD study associated with the solenoid valves.
Mr. Michelson asked whether the use of air as a control mechanism for fire protection systems, and the effects of degraded air on the fire protection systems, have been or being looked into by the Staff or industry.
Dr. Ornstein stated that around 1980 or 1981, a bulletin was i
issued requiring all licensees to look at the interaction between solenoid operated valves and fire protection systems.
Mr. Michelson asked about the use of air for starting and operating diesel generators and the associated problems. Dr. Ornstein stated that all emergency diesel generators (EDGs) use air to start.
Some of the diesels require air for continuous operation, and some require air to shut down.
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.4 Auxiliary & Secondary Systems Meeting Minutes January 11, 1989 Mr. Carroll asked whether each EDG is supplied with air by a safety-grade system. Dr. Ornstein stated that typically the EDGs have a dedicated air start system, consisting 'of high pressure compressors and air receiver tanks.
In many plants, the starting air compressors are not safety grade. However, the air receiver tanks and the piping downstream of the tanks are safety grade at all plants.
I Mr. Carroll asked how the supply of air is assured to those EDGs that need air for continuous operation.
Dr. Ornstein stated.that since the compressors are not safety grade, they may fail during a seismic event.
Under such situation, the diesels will run until the air in the receiver tanks are completely depleted. The NRC and the industry are aware of this problem and it is being looked into.
He said that Zion, Cooper, Brunswick, and McGuire plants use the type of diesels that require air for continuous operation.
Dr. Siess asked what is the probability of loosing the compressors during a seismic event.
Dr. Ornstein stated that they have not looked at the probabilities of failure of compressors due to earthquakes.
Dr. Siess asked whether there are other plants that use air for continuous operation of EDGs. Dr. Ornstein stated the four plants mentioned above are the ones that fall into this category. NRR plans to
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review these plants and recommend necessary modifications to assure continuous supply of air to EDGs. Other plants that use diesels that require air only to start will not be reviewed because even if the compressor fails, the air in the receiver tank would be adequate to start the diesels.
Dr. Burdick stated that the issues associated with EDGs are being looked into under the Generic Issue B-56, " Diesel Generator Reliability."
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Auxiliary & Secondary-Systems Meeting Minutes January 11, 1989 Mr. Michelson commented that it becomes more and more apparent that the Staff is not integrating related Generic Issues.
If an issue, such as.
the one related to air systems problems, is being dealt with by several Generic Issues, and if one of the Generic Issue dealing with a part of the overall problem is solved, the Staff should make it clear what has been resolved and what'else remains to be resolved.
Dr. Siess stated that the existing diesel generator reliability data is based on operating experience. This data base does not involve seismic events, because, to his knowledge, nobody has ever started a diesel generator during an earthquake. He wondered whether anyone has tried to determine the diesel generator reliability during seismic events.
UTILITY EXPERIENCE WITH AIR SYSTEMS - MR. J. HAYES, TOLEDO EDISON, CO.
Mr. Hayes from the Toledo Edison Company stated that as part of the startup effort following the June 9, 1985 incident at the Davis Besse plant, a complete review of the station and IA systems was performed.
Subsequently, the B&W Owners Group, as part of its Safety and Perfor-mance Improvement Program, established a set of criteria for use by the owners of B&W plants in the following areas:
Eouipment and Design Criteria Criteria in this area include the following (Attachment C, Pages 1-6):
- A minimum of three full capacity oil free compressors should be provided for station and IA systems.
Capability for starting all compressors from the control room should be provided.
One micron air filters should be used after the driers.
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- Control room indications should be provided for on/off status of all air compressors, instrument header pressure, etc.
- Provisions for measuring the differential pressure on air filters should be included.
- Continuous blowdown orifices and/or drain traps should be installed especially in dead-end runs of the air systems.
Maintenance and Testino Criteria Some of the tests to be performed under this criteria are as follows (Attachments,Pages7-11):
- Dew point verification tests at drier outlet.
- Tests on isolation valves to assure setpoint accuracy and leak tightness.
- Start tests on backup and emergency compressors.
- Tests to determine the differential pressure on filters.
Criteria for Establishing Loss of Air Response Procedures Criteriainthisareaincludethefollowing(Attachments,Pages11-16):
- As a minimum, the plant should have an emergency procedure specif-ically addressing the loss and restoration of IA.
- The procedure should have a list, describing the symptoms associ-ated with various loss of air scenarios.
- The procedure should include types of actions to be taken by the operator to achieve plant stability upon loss of air.
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- The procedure should list and identify all air-operated valves bcd
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their expected failure position.
- Instructions on how to recover from a partial and/or total loss of IA should be included in the procedure.
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- Operators and plant personnel should be trained for coping with' l
different types of loss of air incidents.
- Plant personnel should be trained on the importance of the IA system.
Simulator Simulation of the loss of air should be incorporated in the revisions to the simulator software.
Mr. Michelson' asked about the type of materials used for air systems piping. Mr. Hays stated that some plants use carbon steel and some other plants use_ stainless steel.
Davis Besse plant used red brass.
Mr. Michelson asked whether it is a common practice to include provi-sions for blowing down the bottom of accumulators. Mr. Hays responded that it is not a common practice throughout the industry. However, changes are being made at the Davis Besse plant to include such pro-visions.
Mr. Michelson asked whether they had performed any gradual loss of air pressure test at the Davis Besse plant. Mr. Hays stated that in 1986 they performed such a test in accordance with the requirements of the INP0 SOER. They dropped the pressure on the upstream of the accumula-tors to assure that the accumulators held the specified pressure. Then, they performed the test on the components to assure that they will I
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. Auxiliary & Secondary Systems Meeting Minutes. January 11, 1989 operate with the accumulators as the air pressure source. He added that
.in his opinion requiring licensees to perform a gradual loss of air-pressure test is not a good idea.
Mr. Michelson stated that since operating experienc^ reveals that gradual loss of air pressure events may lead to some unwanted plant conditions, we need to perform such tests to. understand how the gradual loss of air pressure situation affects the plant.
Mr. Hayes stated that the requirements included in the Generic Letter 88-14 are ambiguous.
It is not made clear what exactly the Staff wants the licensees to do.
It seems that the Generic Letter requires one time testing of the IA system to assure that it operates properly.
If a licensee performs the tests in accordance with the Generic letter and found that everything is working properly, that does not mean that the systems will work properly the next time.
Dr. Burdick stated it is not the intent of the Staff to require one time testing of the IA systems. The Generic Letter requires that the licens-ees maintain proper air quality on a continuous basis. Dr. Ornstein stated that the forthcoming ANSI /ASME Standard will provide clear guidance on what should be done to assure proper operation of the air systems.
Mr. Michelson asked whether the ANSI /ASME Standard will include guidance for performing gradual loss of air pressure test. Dr. Ornstein stated that to his knowledge it is not included in thct Standard.
Dr. Siess stated that he does not believe that tests have to be per-formed to determine the safety significance of the gradual loss of air pressure problem. He believes that, instead of tests, analysis could be done to prove the same point.
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Mr. Carroll asked whether other Owners Groups (such as Westinghouse and
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Combustion Engineering) are taking similar steps to improve the perfor-mance of the air systems. Mr. Hayes and Dr. Ornstein stated that they do not know what the other Owners Groups are doing in this area.
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HISTORY OF GENERIC ISSUE 43, " AIR SYSTEMS RELIABILITY" - DR. G..BURDICK, RES Dr. Burdick reviewed briefly the history of Generic Issue 43, stating that in September 1981, AE0D issued an immediate action memorandum regarding desiccant contamination of IA lines. The AEOD memorandum was prompted by an incident at Rancho Seco where the slow closure of a containment isolation valve resulted from the presence of desiccant particles in the valve operator. Desiccant contamination of the plant IA system was also found to be one of the contributing causes of the loss of the salt water cooling system at the San Onofre plant in March 1980.
In response to the AEOD memorandum, NRR established a working group to determine the generic implications of air system contamination and to develop recommendations accordingly.
Generic Issue 43 entitled, " Con-tamination of Instrument Air Lines," was initiated.
In 1982, a study performed by the Oak Ridge National Laboratory found that air systems problems do not pose a significant challenge to plant safety, and thereby concluded that no changes to the existing NRC regulations were necessary.
In 1983, based on the results of the Value/ Impact analysis, NRR recommended that this issue be dropped from further consideration.
Comments received from the ACRS and AEOD on the NRR recommendation to drop this issue indicated that this issue should be broadened to include all causes of air system unavailability and reprioritized. NRR agreed to reevaluate this issue after the completion of the AEOD case study on air systems problems. The AE0D study was completed in March 1987 and published in Volume 2 of NUREG-1275, dated December 1987.
Since the AE0D study concluded that there had been a multitude of important
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precursor events'due to degraded or malfunctioning air systems, Generic Issue 43 was reopened, broadened in scope and retitled " Air Systems Reliability." Based on the results of the reevaluation, this issue was assigned with a High priority ranking.
Dr. Burdick stated a Technical Assistance Program was initiated at the BrookhavenNationalLaboratory(BNL)toobtaininformationforusein the resolution of Generic' Issue 43. A subcontract was issued by BNL to SAIC to initiate a program to:
- Assess the risk significance of air systems problems.
- Review operating events associated with air systems.
- Develop an Air Systems Reliability Program.
- Develop'a Regulatory Guide.
- Assess the program impact on licensees.
He said that the first two tasks mentioned above have been completed, and the results of these tasks will be included in a MUREG/CR report.
IA SYSTEM RELIABILITY PROGRAM - MR. E. LOFGREN (SAIC)
Mr. Lofgren stated that the main objective of this program is to perform the five tasks previously mentioned by Dr. Burdick. He said that he is
- going to discuss the work done only in the first two tasks. They have performed a review of 14 PRAs, 8 of them in detail, to find out the way in which these PRAs modelled the IA system sequences and how the risk from IA system problems were calculated. They have also reviewed certain operating events associated with IA systems that are listed in Volume 2 of NUREG-1275.
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Auxiliary & Secondary Systems Meeting Minutes January 11, 1989 Mr. Lofgren stated that based on the information gathered from the review of PRAs and operating events, it was found out that 30 percent of the IA system problems were attributable to contamination, 20 percent to human error during operation end maintenance, 17 percent to design errors, 14 percent to mechanical failures, and 12 percent to leakage.
It was also observed that the total events due to IA system problems were more at BWRs than at PWRs.
1 Mr. Lofgren discussed briefly the treatment of the loss of IA sequences in several PRAs, condit $nal core-damage probability associated with events resulting fro; IA system problems, and emergency diesel genera-tor /IA accident sequence precursers (Attachment C, Pages 17-20).
Mr. Lofgren stated that the conclusions and recommendations of the work performed under tasks 1 and 2 include the following:
- The need for an IA system reliability program does not appear to be justified by the risk attributable to IA.
- Attention to IA system is warranted because of plant-specific design weaknesses and potential for common-cause failures.
- Petential IA system related problems will be addressed by:
- Generic Letter 88-14 (already issued)
- Individual Plant Examination Program i
- Emergency diesel generator reliability program, NUREG/CR-5078.
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He said that they plan to perform the following additional work:
- Consequence estimate reanalysis.
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- Review of overpressure events.
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- Review of common-cause failures.
- Preparation of NUREG/CR to document the results and conclusions.
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Mr. Michelson asked whether any of the PRAs looked at the gradual loss of IA system pressure issue. Mr. Lofgren stated that the PRAs did not model this issue explicitly. All of the PRAs looked at the instan-taneous loss of IA system pressure events.
Mr. Michelson asked whether the effects of HVAC system loads on IA systems were looked into by the PRAs. Mr. Lofgren rtated that he does r.ot believe this issue was included in the PRAs.
Mr. Michelson asked whether any of the PRAs looked at the effects of j
elevated temperature on solid state control systems. Mr. Lofgren stated that some of the PRAs did look at this issue but not in detail.
Stating that based on the work performed so far it was concluded that risk from IA system problems is not that significant for most plants, Dr. Siess asked why they want to perform additional work. Dr. Burdick stated that additional work is to confirm the conclusions reached so far. Also, they would like to analyze more data to assure that IA system overpressure issue and gradual loss of IA system pressure issue are not major risk contributors.
Dr. Siess wondered in view of the budget constraints why RES plans to do additional work in this area which, in his opinion, will not have much use in the licensing process.
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L Auxiliary & Secondary Systems Meeting Minutes January 11, 1989 RESOLUTION OF GENERIC ISSUE 43 - DR. G. BUPDICK, RES l
Dr. Burdick discussed the industry and NRC Staff activities associated with the improvement of the IA systems reliability (Attachment C, Pages 21-25).
Some of the activities of the industry are as follows:
- INP0 has already issued SOER (No. 88-1) dated May 1988, covering many events included in NUREG-1275, and providing recommendations for improvement.
- Electric Power Research Institute (EPRI) has some efforts ongoing in this area. A report on Pneumatic Systems and Nuclear Plant Safety, NSAC-128, has been issued in October 1988, providing information on air systems problems and recommendations for im-provement.
- Individual Plant Examination Program is expected to deal with the air systems problems.
- A forthcoming ANSI /ASME Standard on Performance Testing of Nuclear Power Plant Instrument Air Systems is expected to provide guidance to the industry to improve the performance and reliability of air systems.
Dr. Burdick stated that the NRC Staff activities related to air systems include the following:
- Diesel generator reliatMlity program related to the resolution of Generic Issue B-56 addresses air systems issues.
- Proposed rule on Maintenance provides guidance for performing proper maintenance on air systems.
- Two Information Notices (87-28 and Supplement 1 to 87-28) have been issued to all licensees.
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' NUREG-1275 has been sent to all licensees.
- Generic Letter 88-14 has been issued, requiring licensees to take certain steps to improve the reliability of air systems.
Dr. Burdick stated that based on the following, the Staff believes that Generic Issue 43 has been resolved:
- Licensee actions in response to Generic Letter 88-14 are expected to assure the' compatibility between plant air systems and the equipment they serve.
- Prudent 1icensee actions will provide assurance that safety-related air-operated equipment will be capable of performing in accordance with plant safety analyses, i
- Once the design verification activities outlined in Generic Letter 1
88-14 are completed, vigilance must be exercised to assure con-tinued reliable performance of the pneumatic equipment.
- Implementation of a performance standard such as the forthcoming
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ANSI /ASME standard, " Performance Testing for Nuclear Power Plant Instrument Air Systems," will assure continued satisfactory perfor-mance of air systems and the equipment served t'y them.
- The two part approach (design verification and performance testing) will help assure that air systems are adequate to meet their requirements over plant lifetime.
- The RES evaluation of the IDCOR IPE methodology will include the air system as one of those to be examined for system interdepen-dencies.
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1 Auxiliary & Secondary Systems Meeting Minutes January 11, 1989 The Staff believes that from the combined effects of Generic Letter 88-14, and other agency and industry initiatives, sufficient attention is being given, and is expected to be given in the future, to air systems and related problems.
Mr. Michelson and Mr. Wylie requested a copy of the report, NSAC-128 on Pneumatic Systems and Nuclear Plant Safety.
Dr. Siess asked why the Staff did not mention about the B&W Owners Group Program related to the air systems. Dr. Burdick stated that he was not aware of that program until it was presented to the Subcommittee by Mr.
Hayes of Toledo Edison Company.
Mr. Michelson asked whether the Diesel Generator Reliability Program would include information related to the effects of HVAC system failures on diesel reliability. Dr. Burdick said yes.
Dr. Siess asked why the AE00 recommendation related to the gradual loss of IA system pressure test is not required in the Generic Letter 88-14.
Mr. Lefave from NRR stated that since the NRR management and the CRGR decided that it was a backfit issue, it was not included in the Generic Letter.
j Dr. Siess stated that requiring h test would not necessarily_be a backfit if it was necessary to prove that a plant meets its design basis. He asked whether requiring the licensees to provide information to show that their systems will perform properly under a gradual loss of
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IA system pressure condition would be considered as a backfit. Mr.
Lefave stated that he is not sure.
Dr. Siess asked why the resolution of Generic Issue 43 was issued without giving an opportunity for the ACRS to comment on it. Dr.
- Burdick responded that RES Office Letter No. 3 states that if the l
1 Auxiliary & Secondary Systems Meeting Minutes January 11, 1989 resolution of an issue does not involve additional requirements to be imposed upon licensees, it does not have to be sent to ACRS for comments prior to issuance.
Dr. Siess stated that the ACRS never agreed to such a procedure.
Irrespective of the nature of the resolution, the ACRS should be given an opportunity to comment on the proposed resolution of an issue. The ACRS is obligated to review the proposed resolution of Generic Issues and Unresolved Safety Issues and provide advice to the Commission on the adequacy of these resolutions. He said that he would discuss this matter with Dr. Beckjord, RES Director, at a later date.
Mr. Carroll asked whether requirement 3 in the Generic Letter 88-14 is intended to require that the licensees perform a gradual loss of IA system pressure test. The Staff said it does not explicitly require such tests.
SUBCOMMITTEE REMARKS Mr.' Michelson stated that in his opinion the gradual loss of air pres-sure issue is an important one. He believes that something should be done to deal with this issue. He suggested that the ACRS bring this j
matter to the attention of the Comnission.
Dr. Siess stated that the Staff has already decided that the gradual loss of air pressure issue is important. Regulatory Guide 1.68.3 already requires that new plants perform such tests.
It is not required in the Generic Letter 88-14 because it is considered to be a backfit issue. He does not believe that they need to perform tests to assure the operation of air-operated safety-related components under a gradual loss of air pressure conditions.
Certain analyses could be done to prove this point. The RES Staff could perform a specific research on this matter, or it could be made as a new Generic Issue.
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After further discussion, the Subcommittee decided to prepare a draft report, including comments and recommendations on the resolution of Generic Issue 43, and submit it to the full Committee for consideration and approval during the January 12-14, 1989 ACRS meeting.
Mr. Michelson thanked all participants and adjourned the meeting at 1:30 p.m.
NOTE:
Additional meeting details can be obtained from a transcript of this meeting available in the NRC Public Document Room.
2120 L Street, N.W., Washington, D.C. 20006, (202) 634-3273, or can be purchased from Heritage Reporting Corporation, 12?0 L Street, N.W., Suite 600, Washington, D.C. 20005,(202) 628 4888.
x LIST OF DOCUMENTS SUBMITTED TO THE AUXILIARY AND SECONDARY SYSTEMS SUBCOMMITTEE JANUARY 11, 1989 1.
Tentative Presentation Schedule.
2.
NUREG-1275. Volume 2. " Operating Experience Feed Back Report - Air Systems Problems, dated December 1987.
(Note: This document ~
includes the AEOD Case Stud U.S. Light Water Reactors.)y Report C701, Air Systems Problems at 3.
Information Notice No. 87-28, Air Systems Problems at U.S. Light Water Reactors, dated June 22, 1987.
4 Supplement I to Information Notice NO. 87-28, dated December 28, 1987.
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Memorandum from B. Sheron, RES, to L. Shao, NRR, " Proposed Generic LetteronInstrumentAir(IA)SystemProblems,"datedJune23, 1988.
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Initial version of Generic Issue 43, " Contamination of Instrument Air Lines," dated November 30, 1983.
7.
Redefined version of Generic Issue 43, " Reliability of Air Sys-tems," dated April 11, 1988.
8.
Resolution of Generic Issue 43, " Air Systems Reliability,"'includ-ing Generic Letter 88-14.
9.
Minutes of the October 1,1987 Auxiliary Systems Subcommittee Meeting.
- 10. Memorandum from T. Novak, AE0D, to B. Sheron, RES, regarding Peview and Comments on Draft Report, "A Risk-Based Review of Instrument Air Systems at Nuclear Power Plants," dated August 18, 1988.
11.
Presentation Materials provided to the Subcommittee during the meeting.
ATTACHMENT A
.1 REVISED 12/15/88 j
PRESENTATION SCHEDULE ACRS SUBCOMMITTEE MEETING ON THE T:
AUXILIARY AND SEC0hDARY SYSTEMS JANUARY 11, 1989 t
ROOM P-114, 7920 NORFOLK AVENUE BETHESDA, MARYLAND ACRS CONTACT:
Sam Duraiswamy 301-492-9522 NOTE:
- Presentation Time should not exceed 50% of the Total Time
. allocated for a specific item. The remaining 50% of the time is reserved for the Subcommittee questions and answers by the Staff or its contractors.
- Number of copies of the presentation materials to be submitted to the Subcommittee:
25 copies.
TOTAL PRESENTATION ITEM PRESENTER TIME ACTUAL TIME 1.
EXECUTIVE SESSION 10 min 8:30 - 8:40 am 2.
CONTROL AIR SYSTEM DESIGN AND OPERATING EXPERIENCE a.
AEOD Report on Air' Herold Ornstein 60 min 8:40 - 9:40 am Systems Problens (NRC/AEOD) b.
Utility Experience John Hayes 60 min 9:40 - 10:40 am With Air Systems (ToledoEdison)
- BREAK ***
10 min 10:40 - 10:50 am c.
Proposed Resolution Garry Burdick 60 min 10:50 - 11:50 am of Generic Issue 43, (NRC/RES)
" Air Systems Reli-ability" 3.
SUBCOMMITTEE REMARKS 10 min 11:50 - 12:00N
- ADJOURN ****
12:00 Noon AT7ticnMid 0
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1.0 EQUIPMENT / DESIGN CRITERIA A.
THREE (MINIMUM) FULL-CAPACITY OIL-FREE INSTRUMENT AND STATION AIR COMPRESSORS.
'fHIS NUMBERo0F
. COMPRESSORS WILL ALLOW FOR MAINTENANCE ON ONE'AND
~
ALSO L0SS OF THE LEAD:
ONE LOADED LESS THAN FULL TIME FOR INSTRUMENT.
AIR SUPPLY ONE LOADED LESS THAN FULL TIME FOR STATION AIR SUPPLY ONE IN STANDBY B.
CONTROL ROOM REMOTE START-CAPABILITY FOR ALL COMPRESSORS.
C.
AUTOMATIC LOW-PRESSURE ACTUATION OF STATION AIR CROSSOVER.
D.
MANUAL BYPASS VALVES AROUND l
AUTOMATIC BACKUP-AIR ISOLATION VALVES (S)
ANY OTHER AUTOISOLATION VALVES DRIERS FILTERS
~3~
C -3
E.
AUTOISOLATION VALVES AT MAJOR HEADERS TO ISOLATE LOW-PRESSURE ZONES.
F.
CONTROL ROOM ACTUATED ISOLATION CAPABILITY BETWEEN SITE UNITS USING SHARED AIR SYSTEMS, G.
ONE MICRON AIR FILTERS AFTER THE DRIER (ALLOWED 3 MICRONS IN INSTRUMENT AIR SYSTEMS ANSI S7,3-1975).
H.
MAINTAIN REQUIRED DEW POINT AT THE OUTLET OF THE DRIER (18'F BELOW MINIMUM LOCAL RECORDED AMBIENT TEMPERATURE AT PLANT SITE ANSI S7,3-1975),
I, RECORDING DEW PolNT MONITOR LOCATED DOWNSTREAM OF THE DRIER POST-FILTER.
J, CONTROL ROOM INDICATORS FOR:
ON/0FF STATUS OF ALL AIR COMPRESSORS INSTRUMENT HEADER PRESSURE LOOP OR DEAD RUN HEADER PRESSURES PRESSURE DOWNSTREAM FROM AUTOISOLATION VALVES l L c-4
a K.
AIR FLOWMETER DOWNSTREAM OF DRIERS.
L.
COMPRESSOR INTAKES LOCATED IN A LOW HUMIDITY, LOW TEMPERATURE ENVIRONMENT.
M.
AUTOMATIC BYPASS VALVES AROUND BOTH THE DRIER AND
, FILTERS BASED ON INSTRUMENT LOW HEADER PRESSURE ~
4 WITH A CONTROL ROOM INDICATOR.
N.
PRESSURE DIFFERENTIAL MEASUREMENTS'ON AIR FILTERS FOR CHANGE 0VT FREQUENCY.
O.
OIL SEPARATOR FILTERS BETWEEN STATION AIR COMPRES-SORS AND THE INSTRUMENT AIR SYSTEM.
(ALLOWED 1 PPM HYDROCARBON CONTENT BY WEIGHT IN INSTRUMENT AIR STREAM ANSI S7.3-1975).
P.
DESICCANT TYPE DRIERS AND FILTERS SHOULD BE ABLE TO WITHSTAND MAXIMUM AIR FLOW FROM ALL AVAILABLE COMPRESSORS FOR THE LENGTH OF TIME IT WLULD TAKE TO MANUALLY BYPASS OR ELSE AUT0 BYPASS TO PREVENT FLOW RESTRICTION AND/OR DESICCANT BREAKTHROUGH ON THE ACTUATION OF ALL COMPRESSORS. C-5
Q.
EMERGENCY AIR SUPPLY WITH INDIVIDUAL LINES TO CRITICAL. VALVES AND AUT0 START ON LOW HEADER L
PRESSURE.
THIS SUPPLY SHOULD BE ABLE TO FUNCTION
-DURING THE LOSS OF OFF-SITE POWER.
R.
LOCAL VALVE ACCUMULATORS SHOULD BE MOUNTED SO THAT AIR LINES ENTER ON TOP AND THE BOTTLES HAVE DRAIN FITTINGS.
S.
MODULATING VALVES SHOULD Fall AS-IS ON LOW PRES-SURE WITH CONTROL ROOM REMOTE OPERAi10N AND INDICATION OF THE ACTUAL POSITION.
T.
CHECK VALVES SHOULD BE BETWEEN THE RESPECTIVE COMPRESSOR AND RECEIVER S0 THAT THE FAILURE OF THE COMPRESSOR DOES NOT FAIL THE SYSTEM BY PERMIT-TING BACKFLOW.
U.
CONTINUOUS BLOWDOWN ORIFICES AND/0R DRAIN TRAPS SHOULD BE INSTALLED (ESPECIALLY IN DEAD-END RUNS OR FLOW FLOW PORTIONS OF THE AIR SYSTEM) TO REDUCE MOISTURE AND CONDENSATION BUILDUP.
I l
< {
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e V.
PIPING SHOULD BE CONSTRUCTED OF NON CORROSIVE NON SCALING MATERIAL.
2.0 MAINTENANCE / TESTING CRITERIA THE FOLLOWING PROGRAM CONSTITUTES A' REASONABLY COMPREHENSIVE TEST WITH FEATURES RANGING FROM EQUIPMENT' PERFORMANCE TRENDING TO GUIDE MAINTENANCE.
THE TESTS DESCRIBED PROVIDE GENERAL GUIDANCE FOR A TESTING PROGRAM.
SUGGESTED
^
COMPONENT TEST PERIODICITY DRIER OUTLET DEW POINT VERIFICATION WEEKLY CRITICAL VALVES WATER INSPECTION /
TO BE ESTABLISHED (POSITIONER / AIR DRAINING BASED ON HISTORY BOTTLES) 0F WATER ACCUMULATION, SEASON, DRIER PERFORMANCE c-7
f BRANCH'LINE OPERABILITY / STROKING /
REFUELING
- lSOLATION VALVES SETPolNT/ FULL' CLOSURE
' LEAK TIGHTNESS SUGGESTED COMPONENT TEST PERIODICITY AIR COMPRESSOR CAPACITY TREND TO' QUARTERLY' ESTIMATE LEAKAGE AND' COMPRESSOR MARGIN BOTTLED AIR INTEGRITY AND PRESSURE ALTERNATE REFUEL-RESERVOIRS HOLDING AblLITY ING PERIODS PIPING / JOINTS
_ LEAKAGE WALKDOWN AND
_ BASED.ON COM-FLANGES /
INSPECTION PRESSOR ON/0FF COUPLINGS
_ WATER ACCUMULATION TRENDING AND BLOWDOWN
_ TUBING / PIPING CRACKS
- WATER ACCUML-ATION BASED ON HISTORY AND DRIER PERFORMANCE VARIATIONS OR ABNORMALITIES C-6
. SUGGESTED COMPONENT TEST PERIODICITY BACKUP COMPRESSOR SEQUENCER CHECK 0UT QUARTERLY STARTUP AND AND GENERAL COM-RUN/ LOAD PRESSOR PERFORMANCE FOR TRENDING (VIBRATION,'ETC.)
EMERGENCY COM-SEQUENCER CHECK 0UT QUARTERLY PRESSOR STARTUP AND GENERAL COM-AND'RUN/ LOAD PRESSOR PERFORMANCE FOR TRENDING (VIBRATION, ETC.)
COMPRESSOR VERIFY SETPOINT FOR REFUELING PROTECTIVE EQUIPMENT PROTECTION TRIPS / SYSTEM ENSURE PROTECTION ALARMS TRIPS DO NOT INADVERTENTLY SHUTDOWN SYSTEM C-C
_g_
L__ _.
. - = -
SUGGESTED
. COMPONENT TEST PERIODICITY SPECIAL TEST.
VERIFY AIR PRESSURE REFUELING FOR TURBINE AT VALVES, RESPONSE BYPASS VALVES STROKING, AND RAPID AND ATMOSPHERIC CLOSURE ON LOSS-OF-AIR DUMP VALVES, POSITIONER INSPECTION
' MAIN FEEDWATER, FOR CONTAMINANTS, AND STARTUP DETERIORATION, WATER FEEDWATER CONTROL VALVES FILTERS PRESSURE DROP /ACCUM-TO BE ESTABLISHED LATION (T0 CHECK FOR BASED ON HISTORY
-FILTER REPLACEMENT AND AND DELTA-P ASSESS CONTAMINANT LEVEL OF SYSTEM)
A ONE-TIME EXAMINATION 0F THE CROSS-SECTIONAL l
SIZE OF PARTICULATE l
AND THE CONSTITUENTS IS ALSO DESIRABLE.
( - l() _ _ _ - - _ _ -
v SUGGESTED COMPONENT TEST PERIODICITY BACKUP CROSS-VERIFY MANUAL BYPASS.
WEEKLY.
CONNECTIONS IS NORMALLY CLOSP; n3 STATION AIR AND OTHER AIR-VERIFY OPERABILITY OF QUARTERLY SOURCES
' AUTOMATIC OPENING; q
OPENING SETPOINTS.
3.0 CRITERIA FOR LOSS-OF AIR RESPONSE PROCEDURES A.
AS A MINIMUM, THE PLANT SHOULD HAVE AN EMERGENCY PROCEDURE SPECIFICALLY ADDRESSING THE LOSS AND RESTORATION OF INSTRUMENT AIR.
THE PROCEDURE SHOULD BE SEPARATE BUT COMPLEMENTARY TO THE ABNORMAL TRANSIENT OPERATING GUIDELINE (ATOG)
BASED CORE COOLING EMERGENCY PROCEDURES.
THE LOSS-OF-AIR PROCEDURE.SHOULD BE ENTERED VIA THE AT0G PROCEDURE, BUT ACTIONS FOR LOSS OF AIR SHOULD NOT TAKE PRECEDENCE OVER ATOG ACTIONS FOR CORE COOLING REQUIREMENTS.
m ~II
s B.
THE PROCEDURE SHOULD BE " STAGED" SO THAT SPECIFIC 0PERATOR ACTIONS ARE TO BE TAKEN AT VARIOUS AIR SUPPLY HEADER PRESSURES.
THE HEADER PRESSURES SHOULD BE BASED UPON THE. PRESSURE AT WHICH CRITICAL COMPONENTS ASSUME THEIR FAILURE POSITION, AND WOULD BE ANALOGOUS TO THE AT0G
. POST-TRIP WINDOW.
C.
THE PROCEDURE SHOULD HAVE A. LIST DESCRIBING THE SYMPTOMS ASSOCIATED WITH VARIOUS LOSS-OF-AIR SCENARIOS (E.G. DRIER PURGE OPEN, TURBINE HEADER BROKEN).
THE PROCEDURE SHOULD IDENTIFY THE LOCATIONS OF MAIN AIR LINE ISOLATION VALVES AND WHICH PORTIONS OF THE' SYSTEM WOULD BE AFFECTED WHEN THEY ARE CLOSED.
THE LOCATIONS SHOULD BE SPECIFICALLY DESCRIBED.
0~l$- _ - _ _ _
t 8
D.
THE OPERATOR ACTIONS ASSOCIATED WITH THE PROCEDURE SHOULD CONTAIN THE FOLLOWING TYPES OF ACTIVITIES INTENDED TO ACHIEVE PLANT STABILITY WHEN AIR IS LOST:
MANUAL REACTOR TRIP OR VERIFICATION OF AUTOMATIC TRIP AT A SPECIFIC DECREASING AIR PRESSURE VERIFICATION OF PLANT STABILITY LOCATION, DETECTION, AND ISOLATION OF BRANCH LINE FAILURES PRESERVATION OF AIR PRESSURE TO CRITICAL COMPONENTS BY ISOLATING VARIOUS USAGE PATHS SHUTDOWN OF OPERATING COMPONENTS (USING AIR)
IF THEIR CONTINUED USE COULD CAUSE EQUIPMENT DAMAGE AND/0R DIFFICULTY WITH CORE COOLING OR STEAM GENERATOR HEAT REMOVAL l
C - 13
CORRECTION FOR CONTAINMENT ISOLATION AFFECTING MAKEUP, LETDOWN AND REACTOR COOLANT PUMP SEAL COOLING i
I CORRECTIONS FOR FAILURES THAT COULD PERMIT' RADIOACTIVE RELEASES (SUCH AS GASE0US WASTE)
E.
THE PROCEDURE SHOULD REQUIRE THE STARTUP AND ALIGNMENT OF ALL AVAILABLE AIR COMPRESSORS.
i F.
EXCEPT AS DIRECTED BY ATOG PROCEDURES, ONLY PLANT
(
STABILITY SHOULD BE ACHIEVED VIA THE USE OF THE PROCEDURE.
THE PROCEDURE SHOULD AVOID OPERATOR MANUAL CONTROL FOR CONTINUED POWER OPERATION, AND EXCEPT AS DIRECTED BY THE AT0G PROCEDURES, PLANT C00LDOWN SHOULD NOT BE CONSIDERED WITH THE LOSS OF AIR.
i i
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_mm_-__m_________m__
__-__..____._m.
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G.
THE PROCEDURE SHOULD LIST AND IDENTIFY ALL AIR-l L
OPERATED VALVES AND THEIR EXPECTED FAILURE POSITION (IDENTIFYING THE AFFECTS OF BOTTLED AIR SUPPLIES)
AND AT WHICH PRESSURE MOVEMENT TO THE FAILURE POSITION OCCURS.
THE VALVES SHOULD BE GROUPED BY.
ISOLABLE HEADER OR BRANCH LINE.
THE PROCEDURE SHOULD LIST ALL PNEUMATIC INSTRUMENTATION AND ITS EXPECTED FAILURE INDICATION OR CONTROL OUTPUT.
H.
THE PROCEDURE SHOULD INCLUDE INSTRUCTION ON HOW TO RECOVER FROM A PARTIAL AND/0R TOTAL LOSS OF INSTRUMENT AIR.. EQUIPMENT THAT COULD LOCK UP (I.E. SPECIAL ACTIONS ARE REQUIRED TO RESTORE THE EQUIPMENT TO A DESIRED CONFIGURATION AFTER AIR PRESSURE IS RESTORED) SHOULD BE IDENTIFIED ALONG WITH THE METHOD FOR RESTORATION.
IF A TRANSIENT CAN.BE CREATED BY RESTORATION, THE PROCEDURE SHOULD ADVISE'THE OPERATION.
CONTROLS OF IMMEDIATE INTEREST INCLUDE TURBINE BYPASS VALVES, ATMOSPHERIC DUMP VALVES, MAIN AND STARTUP FEEDWATER VALVES, AND THE MAIN FEEDWATER PUMP CONTROLLER.
. C-/5 1
i
___---___.-_a
4.0 TRAINING A.
OPERATORS AND PLANT PERSONNEL SHOULD BE TRAINED
~
L FOR VARIOUS LOSS OF AIR SCENARIOS.
ATTENTION SHOULD BE PLACED ON IDENTIFYING THE SYMPTOMS'0F-LOSS OF AIR, LOCATING ISOLATION VALVES TO MINIMIZE THE SYSTEMS LOST, AND KNOWING THE FAILURE POSITION OF KEY VALVES ASSOCIATED WITH DECAY HEAT REMOVAL.
B.
PLANT-PERSONNEL SHOULD BE TRAINED ON THE IMPORTANCE OF THE INSTRUMENT AIR SYSTEM, WHY ITS' USE FOR TOOLS IS PROHIBITED,'AND THE NECESSITY OF IMMEDIATELY REPORTING AIR SYSTEM DAMAGE.
5.0 SIMULATOR A.
THE SIMULATION OF THE LOSS-OF-AIR SHOULD BE INCORPORATED IN REVISIONS TO SOFTWARE, _ ____ _ ___-_- _ - _ _ _ _ _ _ _ _
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