ML20127N892
| ML20127N892 | |
| Person / Time | |
|---|---|
| Issue date: | 03/15/1985 |
| From: | Advisory Committee on Reactor Safeguards |
| To: | Advisory Committee on Reactor Safeguards |
| References | |
| ACRS-2293, NUDOCS 8505230638 | |
| Download: ML20127N892 (11) | |
Text
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DATE ISSUED: 3/15/85 3\\M\\tB PROPOSED MEETING MINUTES FOR THE MARCH 15, 1985 COMBINED ATWS AND ELECTRICAL SYSTEMS SUBCO MITTEES The ACRS Subcomittee on ATWS and Electrical Systems met on March 15, 1985 at 1717 H Street, N.W., Washington, DC. The purpose of the meeting was to:
(1) discuss the NRC Staff and Licensee activities associated with implementation of the ATWS Rule, and (2) discuss the status of NRC actions on the topic of scram breaker reliability. The meeting was for the gathering of information and no specific ACRS actions were planned.
It was initially intended that the representatives of the four vendors' Owners Groups on ATWS would brief the Subcomittee on the Owners Group proposals as to how to best implement the requirements of the ATWS Rule and their actions on the development of reliability assurance programs.
The Owners Groups declined to do this at this Subcommittee meeting. The Subcomittees heard presentations from NRC-RES, NRC-NRR, NRC-IE, and BNL. The meeting began at 8:30 a.m. and adjourned at 5:00 p.m. and was held in open session. The principle attendees were:
W. Kerr Subcomittee Chairman D. Ward ACRS Member J. Ebersole ACRS Member C. Wylie ACRS Member W. Lipinski ACRS Consulcant J. Lee ACRS Consultant P. Davis ACRS Consultant P. Boehnert ACRS Staff R. Savio ACRS Staff M. El-Zeftawy ACRS Staff DEJIC:;rt.'D ORICITAL 850 PDR 38 850315 2293 Cortified By
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ATWS/ Electrical Systems Min. March 15, 1985 l
NRC
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BNL D. Pyatt D. Diamond S. Golberg W. Sheer J. Calvoe G. VanTuyle W. Hodges J. T. Beard N. Vellalva E. Rossi R. Wright HIGHLIGHTS 1.
The final ATWS Rule was published in the Federal Register on June 26, 1984. Owners Groups for all four vendors are currently working with the Licensees to dev.elop procedures and hardware for implementing the rule requirements and reliabiltiy assurance -
programs. A Generic Letter giving guidance for the QA requirements is to be published in the very near future.
(A copy of a draft of this Generic Letter is included as Attachment A.) The following requirements are contained in the ATWS Rule.
(a) All PWRs will be required to have diverse automatic AFW initiation and turbine trip, with CE and B&W plants being required to have diverse scram systems.
(b) All BWR will be required to have ARI systems, increased SLCS flow (nominal 86 gpm), and automatic recirculation pump trips, with new BWRs being required to have automatic SCLS initiation.
The development of reliability assurance programs for reactor protection system equipment is recommended but is not a legal requirement of the rule. The NRC Staff's intent is to have
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ATWS/ Electrical Systems Min. March 15, 1985 j
complete implementation of the rule in about 2 years.
It, however,
.is not certain that this can be accomplished.
2.
It was noted that Westinghouse plants are not required to have diverse scram systems and that the basis is the Westinghouse plants' capability to migitate an ATWS (i.e., more relief valve capacity than other PWRs). The NRC Staff's recommendation to the Commission was to require diverse scram systems for Westinghouse reactors. The Conmission has, however, decided not to impose this requirement. There was some discussion on this point.
It was noted that the NRC's Salem Generic Issues Task Force strongly recommended the use of a diverse scram system on Westinghouse plants. The arguments for diversity are the possibility for the existence of undiscovered common mode failure paths, uncertainty as to the ability of the reactor to mitigate an ATWS, and the need for emphasis on ATWS prevention. There has in addition been some discussion on the possibility for undetected failure in the scram accuation circuitry.
(SeeItem5). Westinghouse representatives stated that Westinghouse was considering making additional changes to the scram systems which would improved system reliability but did not identify what these changes would be.
-3.
NRC is developing QA guidance for the "non-safety-related" ATWS equipment. A proposed Generic Letter was issued for comment in the Federal Register on November 6, 1984 and is now in the final stages of preparation. A copy of the most current draft is included as Attachment A.
The stated objective was that prudent management control be maintained over the design, manufacture, and maintenance of this equipment but that " safety-related" QA requiremer,ts for an independent audit system and record keeping be eased. This was intended to assure, with high reliabilty, that the product specifications would be met and at the same time to reduce the l
difficulties of implementating the current " safety-related QA J
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,4 March 15, 1985-ATWS/ Electrical Systems Min. '
requirements. The pr6 posed Generic Letter was discussed to some extent. The wording used in the Generic Letter does not lead easily to specific requirements.
It was likely that this will have to be devloped further when specific plans for the QA implementa-tion are submitted by the Licensees.
4.
Analysis was performed by BNL under contract to the NRC to assess i
the adequacy of BWR Emergency Procedure Guidelines (EPGs).
Operator action is required to successfully mitigate an ATWS and the EPGs is highly dependent on operator action. The BNL analysis indicates that this action may be difficult to perform. Control of reactor pressure vessel water may be difficult because of level t
oscillations and time delays between flow adjustment and level
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reading indications.
(This time delay may be on the order of 30 to I
60 seconds.) SRV openings would also perturb water level'. The use of depressurization for power control is possible and may be necessary but would need to be carefully controlled. The need for operator training and simulator experience was emphasized.
5.
The recent (January 1985) reactor protection system malfunctions at f
- Sequoyah Unit 2 were discussed.
In this incident a maintenance error resulted in the failure of a solid state component in the undervoltage trip circuit. The equipment was supplied by Westinghouse and all plants with this system can have similiar j
failures. Other failures of this type have been discovered in Westinghouse plants during scram system tests. A schematic of this scram systen is shown in Figure I.
Westinghouse is currently considering scram system modifications which are intended to improve the scram function reliability.
It is not clear at this point as to what changes will be made.
i 6.
The NRC Staff is continuing their post-Salem actions on improving l
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.c ATWS/ Electrical Systems Min. March 15, 1986 the reliability of the scram breaker function. Automatic shunt tripshavebeencombined(wherenotalreadyused)andundervoltage trips cnd breaker replacement interval testing is being carried out.
Improved preoperational inspection and maintenance is also being carried out. The NRC Staff stated that they have not reviewed foreign experience to determine if there are any lessons to be learned.
It does not appear that there are any plans to do this.
NOTE:
Additional meeting details can be obtained from a transcript of this meeting available in the NRC Public Document Room, 1717 H Street, N.W., Washington, D.C, or can be purchased from ACE-Federal Reporters, 444 North Capitol Street, Washington, D.C. 20001,(202)347-3700.
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SUBJEC.T:
QUALITY ASSURANCE GUIDANCE FOR AWS EQUIPMENT THAT IS NOT SAFETY-RELATED On June 1, 1984, the Commission approved publication of a final rule, 10 CFR
- ~ TATWS)gegarding the reduction of risk from anticipated transients without scram
__.. 50.62, events for light-water cooled nuclear power plants (49 FR 26036).
At
- the same time, the Commission directed the staff to complete and issue in the form of a generic letter explicit quality assurance (QA) guidance for non-safety-related equipment encompassed by the.ATWS rule.
Section 50.62(d) of the AWS rule requires that each licensee develoji and submit (to the Director of the Office of Nuclear Reactor Regulation) a proposed schedule for meeting the requirements of the rule within 180 days after issuance of the QA guidance.
The NRC staff issued a proposed generic letter in the Federal Register (49 FR 44337) on November 6, 1984.
The staff has considered the comments from 22 interested parties that were received by December 31, 1984 and has revised the proposed generic letter.
To develop QA guidance for non-safety-related ATWS equipment, the NRC staff both surveyed quality practices applied to non-safety-related equipment at some operating nuclear power plants and reviewed the comments from utilities, industry organizations, and other concerned parties. As a result, the staff continues to view the observed industry practices as acceptable for non-safety-i related ATWS equipment.
The practices that were observed during the plant visits or were described by utilities in their comments generally consisted of the application of quality controls comparable to selected portions of their Appendix B program.
- However, utility procedures and practices did not specifically reference such controls as Appendix B requirements.
l The QA controls in Appendix B to 10 CFR 50 describe one form of a comprehensive management control system for a complex task.
While Appendix B describes only one such system, licensees and applicants have expressed a desire to minimize proliferation of different kinds of management control systems for their plants.
The NRC staff concurs with this desire not to establish new and separate management control systems for non-safety-related ATWS equipment.
Accordingly, Appendix B is viewed as a useful reference in which to frame the staff's guidance for non-safety-related ATWS equipment.
However, this does not mean that the Appendix B QA program, including the adopted regulatory guides and the industry standards, or an' equivalent to such a program is' required to meet the intent of this generic letter.
Further, the use of Appendix B as a reference does not indicate that the guidance in this letter imposes any Appendix B requirements on non-safety-related ATWS equipment, and, therefore, NRC would not judge compliance with this generic letter by using Appendix B or its associated regulatory guides.
Instead, NRC's inspections will focus.on the implementation and effectiveness of the quality controls whose attributes are described in this letter.
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The' enclosure to this letter provides the explicit QA guidance required by 10 CFR 50.62.
The lesser safety significance of the equipment encompassed by 10 CFR 50.62,~as compared to safety-related equipment, necessarily results in less
.. _._. stringent QA guidance. We have incorporated this lesser degree of stringency
.Ep elimin~ating requirements for involvement of parties outside the normal-line organization and requirements for a formalized program and detailed f recordkeeping for all quality practices.
IssuanceofthisQAguidanceshallbeconsid5tedtl1ereferenced'ateinitiating the schedule in 10 CFR 50.62(d).
No response to this letter is required.
Information collection requirements under the ATWS rule were approved by the Office of Management and Budget under clearance number 3150-0011, which expires April 30, 1985 (49 FR 26036, p. 26044).
Comments on burden and duplication may be directed to the Office of Managment and Budget, Reports Management, Room 3208, New Executive Office Building, Washington, DC 20503.
Sincerely, Hugh L. Thompson, Jr., Directo Division of Licensing Office of Nuclear Reactor Regulation
Enclosure:
QA Guidance 9
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l-ENCLOSURE l
l QA GUIDANCE FOR NON-SAFETY-RELATED ATWS EQUIPMENT I
L 10 CFR 50 APPENDIX B l
' REQUIREMENT GUIDANCE I.
ORGANIZATION The normal line organization is expected to
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verify compliance with this guidance.
A separate organization is not required.
If desired, the existing Appendix B QA organization may be involved but this is not required.
- T T i.
il PROGRAM It is expected that the existing body of l
plant procedures or practices will describe l
the quality controls applied to the subject i
equipment. A new or separate QA program is not required.
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III.
DESIGN CONTROL Measures 1 are to be established to ensure design specifications are included or correctly translated into design documents 2/
and to ensure that all design control activities are consistent with the require-ments of 10 CFR 50.59.
Normal supervisory review of the designer's work is an adequate control measure.
IV.
PROCUREMENT DOCUMENT Measures are to be established to ensure CONTROL system specifications and quality require-ments,whereapplicabigareincludedin procurement documents.
1# Except for design control measures, where the utility ~it responsible for ensuring that design control measures are applied at contractor or subcon-tractor organizations, the term " measures" applies only to activities within the licensee's or applicant's organization.
However, the design control measures to be applied at contractor or subcontractor organizations need be no more stringent than those required of the utility.
E xcept for the recordkeeping requirements of 10 CFR 50.59 and requirement E
XVII of this guidance document, any records that are generated as a result of implementing these QA controls are not required to be maintained.
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V.
INSTRUCTIONS, Measures are to be established which ensure ]
PROCEDURES,'AND that quality controls will be applied to d
DRAWINGS activities that affect quality.
These e
- measures may include such things as written instructions, plant procedures, cautionary x.=
notes'on drawings and special instructions on work orders.
Any methodology which i
s provides the appropriate degree of guidance I
i to utility personnel performing quality-l
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related activities will satisfy this
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Maintenance on the equipment
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vendor information.
Any departure from such vendorguidanceshallbpbasedonanadequate i
t engineering rationale.
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VI.
DOCUMENT CONTROL Measures are to be established to. control
,theissuanceofanpchangestodocuments iaffecting quality VII.
CONTROL OF PURCHASED Measures are to be established to ensure ITEMS'AND SERVICES procurementdocuments.grmtoappropriate that all purchases con Such measures may include the performance of receipt inspections by stores or warehouse personnel or plant engineering personnel.
VIII.
IDENTIFICATION AND Measures are to be established, where neces-CONTROL OF PURCHASED sary, to identify and control purchased ITEMS items.
Examples of circumstances requiring such control include the storage of environmentally sensitive equipment or material and the storage of equipment or i
material that has a limited shelf-life.
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.IX.
CONTROL OF SPECIAL Measures are to be established to control PROCESSES special processes, including welding, heat treating, and non-destructive testing.
ApplicableJcodes, standards, specifications, criteria, and other special requirements may serve as the basis of these controls.
1!i M ee footnote'2, page 1.
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10 CFR 50 APPENDIX B GUIDANCE REQUIREMENT X.
INSPECTION Measures are to be established to inspect activities affecting quality.
Inspections are to be accomplished in order to verify thattheseactivitiesareincongraance with the available documentatiom, or, if no documentation is available, to verify that
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these activities are being satisfactorily accomplished.
In general, the line organi-zation is responsible for determining the inspection requirements and for ensuring that sufficient inspections are performed.
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Inspections need not be performed by l
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personnel who are independent of the line organization.
Inspections shall be i
performed by knowledgeable personnel.
l XI.
TESTING Measures are to be established to test, as appropriate, non-safety-related ATWS equipment prior to installation and operation and periodically.
Results of the
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tests should be evaluated to ensure that l
the test requirements have been satisfied.
L XII.
CONTROL OF MEASURING Measures are to be established to control, AND TEST EQUIPMENT calibrate, and adjust measuring and test equipment at specific intervals.
XIII.
HANDLING, STORAGE, AND Measures are to be established to control SHIPPING handling, storage, shipping, cleaning, and preservation of purchases in accordance with utility practices and manufacturer's recommendations.
XIV.
INSPECTION, TEST, AND Measures are to be established to indicate OPERATING STATUS status of inspection, test, and operability l'
of installed non-safety-related ATWS equipment.
XV.
NONCONFORMANCES Measures are to be established to identify nonconformances.
E ee footnote 2, page 1.
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