ML013120051
| ML013120051 | |
| Person / Time | |
|---|---|
| Issue date: | 12/31/2001 |
| From: | Office of Nuclear Regulatory Research |
| To: | |
| Norris W | |
| References | |
| DG-1089 | |
| Download: ML013120051 (16) | |
Text
This regulatory guide is being issued in draft form to involve the public in the early stages of the development of a regulatory position in this area. It hasnot received complete staff review or approval and does not represent an official NRC staff position.Public comments are being solicited on this draft guide (including any implementation schedule) and its associated regulatory analysis or value/impactstatement. Comments should be accompanied by appropriate supporting data. Written comments may be submitted to the Rules and DirectivesBranch, Office of Administration, U.S. Nuclear Regulatory Commission, Washington, DC 20555-0001. Comments may be submitted electronically ordownloaded through the NRC's interactive web site at <WWW.NRC.GOV> through Rulemaking. Copies of comments received may be examined at theNRC Public Document Room, 11555 Rockville Pike, Rockville, MD. Comments will be most helpful if received by March 25, 2002.Requests for single copies of draft or active regulatory guides (which may be reproduced) or for placement on an automatic distribution list forsingle copies of future draft guides in specific divisions should be made to the U.S. Nuclear Regulatory Commission, Washington, DC 20555,Attention: Distribution Services Section, or by fax to (301)415-2289; or by email to DISTRIBUTION@NRC.GOV. Electronic copies of this draftguide are available through NRC's interactive web site (see above), on the NRC's web site <WWW.NRC.GOV> in the Reference Library underRegulatory Guides, and in NRC's Electronic Reading Room at the same web site, under Accession Number ML013120051.
U.S. NUCLEAR REGULATORY COMMISSIONDecember 2001 OFFICE OF NUCLEAR REGULATORY RESEARCHDivision 1 DRAFT REGULATORY GUIDEContact: W.E. Norris (301)415-6796DRAFT REGULATORY GUIDE DG-1089OPERATION AND MAINTENANCE CODE CASE ACCEPTABILITY,ASME OM CODEA. INTRODUCTIONGeneral Design Criterion (GDC) 1, "Quality Standards and Records," of Appendix A,"General Design Criteria for Nuclear Power Plants," to 10 CFR Part 50, "Domestic Licensing of Production and Utilization Facilities," requires, in part, that structures, systems, and components important to safety be designed, fabricated, erected, and tested to quality standards commensurate with the importance of the safety functions to be performed. Where generally recognized codes and standards are used, Criterion 1 requires that they be identified and evaluated to determine their applicability, adequacy, and sufficiency and be supplemented or modified as necessary to ensure a quality product in keeping with the required safety function.Provisions of the American Society of Mechanical Engineers (ASME) Boiler and PressureVessel (BPV) Code have been used since 1971 as one part of the framework to establish the necessary design, fabrication, construction, testing, and performance requirements for structures, systems, and components important to safety. ASME standards committees develop, among other things, improved methods for the construction, inservice inspection (ISI),
and inservice testing (IST) of ASME Class 1, 2, 3, MC (metal containment) and CC (concrete 1 Copies may be obtained from the American Society of Mechanical Engineers, Three Park Avenue, NewYork, NY 10016-5990. Phone (212)591-8500; fax (212)591-8501.
2containment) nuclear power plant components. A broad spectrum of stakeholdersparticipates in the ASME process, which helps to ensure that the various interests are considered.The NRC has committed through its Strategic Plan to use consensus standards toincrease public involvement in the NRC's regulatory development process, consistent with the provisions of Public Law 104-113, the National Technology and Transfer Act of 1995, and Office of Management and Budget (OMB) Circular A-119, "Federal Participation in the Development and Use of Voluntary Consensus Standards and Conformity Assessment."
To further the NRC's commitment in the Strategic Plan and because ASME Code provisions have played a significant role in the regulatory process, the NRC proposes to endorse for the first time ASME Operation and Maintenance (OM) Code Cases.In 1990, the ASME published the initial edition of the OM Code, which providesrules for IST of pumps and valves. The OM Code was developed and is maintained by the ASME Committee on Operation and Maintenance of Nuclear Power Plants (ASME OM Committee). The OM Code was developed in response to the ASME Board on Nuclear Codes and Standards directive that transferred responsibility for development and maintenance of rules for the IST of pumps and valves from the ASME Section XI Subcommittee on Nuclear Inservice Inspection to the ASME OM Committee. The ASME intended the OM Code to replace Section XI rules for IST of pumps and valves, and the Section XI rules for IST of pumps and valves that had been incorporated by reference into NRC regulations have been deleted from Section XI. The NRC endorsed the OM Code for the first time in an amendment to 10 CFR 50.55a published on September 22, 1999 (64 FR 51370).In 10 CFR 50.55a, "Codes and Standards," paragraph (f), "Inservice TestingRequirements," requires, in part, that Class 1, 2, and 3 components and their supports meet the requirements of the "Code for Operation and Maintenance of Nuclear Power Plants,"1 of the ASME OM Code or equivalent quality standards. The ASME publishes anew edition of the OM Code every three years, and new addendum every year. The latest editions and addenda of the OM Code that have been approved for use by the NRC are referenced in 10 CFR 50.55a(b). The ASME also publishes OM Code Cases yearly.
Code Cases provide alternatives developed and approved by ASME or explain the intent of existing Code requirements. This regulatory guide identifies the Code Cases that have been determined by the NRC to be acceptable alternatives to applicable parts of the OM Code. In the past, the acceptability of Code Cases related to Section XI rules for IST of pumps and valves were addressed in Regulatory Guide 1.147, "Inservice Inspection Code Case Acceptability, ASME Section XI, Division 1." With the endorsement of the OM Code, the NRC determined that a new guide for endorsement of Code Cases related to the OM Code should be developed. These Code Cases may be used by licensees, without request to the NRC, provided they are used with any identified limitations or modifications. OM Code Cases not yet endorsed by the NRC may be implemented through 10 CFR 50.55a(a)(3), which permits the use of alternatives to the Code requirements referenced in 10 CFR 50.55a provided the proposed alternatives result in an acceptable level of quality and safety and provided their use is authorized by the Director of the Office of Nuclear Reactor Regulation.
3The use of Code Cases contained in this guide is voluntary. The ASME Code isincorporated by reference into 10 CFR 50.55a. Code Cases approved by the NRC provide an acceptable voluntary alternative to the mandatory ASME Code provisions.
Thus, generic approval of a Code Case through this guide of an alternative to compliance with these provisions must be accomplished through an amendment to 10 CFR 50.55a.
The NRC plans to publish for public comment an amendment to 10 CFR 50.55a that would incorporate this guide by reference. The proposed amendment to 10 CFR 50.55a will state the requirements governing the use of Code Cases. Because of the continuing change in the status of Code Cases, periodic updates to 10 CFR 50.55a and this guide are planned to accommodate new Code Cases and any revisions of existing Code Cases.Regulatory guides are issued to describe to the public methods acceptable to theNRC staff for implementing specific parts of the NRC's regulations, to explain techniques used by the staff in evaluating specific problems or postulated accidents, and to provide guidance to applicants. Regulatory guides are not substitutes for regulations, and compliance with regulatory guides is not required. Regulatory guides are issued in draft form for public comment to involve the public in developing the regulatory positions. Draft regulatory guides have not received complete staff review; they therefore do not represent official NRC staff positions. This regulatory guide does not contain a new or amended information collectionrequirement subject to the Paperwork Reduction Act of 1995 (44 U.S.C. 3501 et seq.).
Existing requirements were approved by the Office of Management and Budget, and the approval number is 3150-0011. If a means used to impose an information collection does not display a currently valid OMB control number, the NRC may not conduct or sponsor, and a person is not required to respond to, the information collection.B. DISCUSSIONThe NRC is proposing to publish a regulatory guide that contains the OM CodeCases that are acceptable to the NRC for implementation in the IST of light-water-cooled nuclear power plants. The NRC staff reviewed Code Cases OMN-1 through OMN-13 for inclusion in this guide. Appendix A lists the OM Code edition or addenda for each Code Case, with the date of approval by the ASME Board on Nuclear Codes and Standards.
Appendix B is a numerical listing of the OM Code Cases. In the Regulatory Position, Table 1, "Acceptable OM Code Cases," lists the Code Cases that are acceptable to the NRC for implementation in the IST of light-water cooled nuclear power plants. Table 2, "Conditionally Acceptable OM Code Cases," lists the Code Cases that are acceptable provided they are used with the identified limitations or modifications, i.e., the Code Case is generally acceptable but the NRC has determined that the alternative requirements must be supplemented in order to provide an acceptable level of quality and safety. Code Cases that the NRC has determined to be unacceptable will be listed in a new regulatory guide, which is being developed as DG-1112, "ASME Code Cases Not Approved for Use."Code Cases provide alternatives that were developed and approved by ASME toexisting Code requirements. The NRC plans to incorporate by reference the Code Cases listed as approved in Tables 1 and 2 of this guide into 10 CFR 50.55a. The Code Cases may be used voluntarily by licensees as an alternative to compliance with ASME Code provisions that have been incorporated by reference into 10 CFR 50.55a.
4The proposed amendment to 10 CFR 50.55a being developed would require thatwhen a licensee initially implements a Code Case, the most recent version of that Code Case as listed in Tables 1 and 2 be implemented. If a Code Case is implemented by a licensee and a later version of the Code Case is incorporated by reference into 10 CFR 50.55a and listed in Tables 1 and 2 during the licensee's present 120-month IST program interval, that licensee could use either the later version or the previous version (unless a specific limitation or condition is placed on the use of that Code Case, in which case the modification or limitation applies). Licensees who choose to continue use of the Code Case during the subsequent 120-month IST program interval will be required to implement the latest version incorporated by reference into 10 CFR 50.55a and listed in Tables 1 and 2.Code Cases may be annulled because experience has shown that an examinationor testing method is inadequate or the application for which it was specifically developed no longer exists. If a Code Case is incorporated by reference into 10 CFR 50.55a and later annulled by the ASME, the NRC will amend 10 CFR 50.55a and this guide to remove the approval of the annulled Code Case. Licensees should not begin to implement annulled Code Cases in advance of such rulemaking. After a Code Case is annulled and 10 CFR 50.55a and this guide are amended, licensees may not implement that Code Case for the first time. However, a licensee who implemented the Code Case prior to annulment may continue to use that Code Case through the end of the present 120-month IST program interval unless 10 CFR 50.55a specifically prohibits further use of the annulled Code Case. An annulled Code Case cannot be used in the subsequent 120-month IST program interval unless implemented as an approved alternative under 10 CFR 50.55a(a)(3).With regard to the use of any Code Case, it is the responsibility of the user to makecertain that no regulatory requirements are violated and that there are no conflicts with other limitations resulting from Code Case usage.C. REGULATORY POSITION1. ACCEPTABLE CODE CASESThe Code Cases listed in the table below are acceptable to the NRC for applicationin licensee's OM IST programs. Note: the ASME issues OM Code Cases once each year when a new edition or addenda of the OM Code is published. To assist users of the OM Code, Column 3 of Table 1 lists the edition or addenda to which each Code Case was attached (E is for edition; A is for addenda), and whether the Code Case is new or reaffirmed.TABLE 1 - ACCEPTABLE OM CODE CASES 5CODE CASENUMBERTABLE 1, ACCEPTABLE OM CODE CASESEDITION/
ADDENDAOMN-2, Rev. 0Thermal Relief Valve Code CaseNew 1998EOMN-5, Rev. 0Testing of Liquid Service Relief Valves Without InsulationNew 1999AOMN-6, Rev. 0Alternative Rules for Digital InstrumentsNew 1999AOMN-7, Rev. 0Alternative Requirements for Pump TestingNew 2000AOMN-8, Rev. 0Alternative Rules for Preservice and Inservice Testing ofPower-Operated Valves That Are Used for System Control and Have a Safety Function per OM-10New 2000AOMN-13, Rev. 0Requirements for Extending Snubber Inservice VisualExamination Interval at LWR Power PlantsNew 2000A2. CONDITIONALLY ACCEPTABLE CODE CASESThe Code Cases listed in Table 2 are acceptable to the NRC for application inlicensee's OM IST programs within the limitations imposed by the NRC. Unless otherwise stated, limitations imposed by the NRC are in addition to the conditions specified in the Code Case. Note that the ASME issues OM Code Cases once each year when a new edition or addenda of the OM Code is published. To assist users of the OM Code, Column 3 of Table 2 lists the edition or addenda to which each Code Case was attached (E is for edition; A is for addenda), and whether the Code Case is new or reaffirmed.TABLE 2, CONDITIONALLY ACCEPTABLE OM CODE CASESCODE CASENUMBERTABLE 2, CONDITIONALLY ACCEPTABLE OM CODE CASESEDITION/ADDEND ACONDITIONOMN-1, Rev.
0Alternative Rules for Preservice and Inservice Testing of CertainMotor-Operated Valve Assemblies in Light-Water Reactor Power Plants Reaffirme d 1999ALicensees may use Code Case OMN-1, "Alternative Rules forPreservice and Inservice Testing of Certain Electric Motor-Operated Valve Assemblies in Light-Water Reactor Power Plants," Revision 0, in lieu of the provisions for stroke-time testing in Subsection ISTC of the 1995 Edition up to and including the 2000 Addenda of the ASME OM Code when applied in conjunction with the provisions for leakage rate CODE CASENUMBERTABLE 2, CONDITIONALLY ACCEPTABLE OM CODE CASESEDITION/ADDEND ACONDITION 6OMN-1, Rev.
0 (Continued)Alternative Rules for Preservice and Inservice Testing of CertainMotor-Operated Valve Assemblies in Light-Water Reactor Power PlantsReaffirme d 1999Atesting in, as applicable, ISTC 4.3 (1995 Edition with the 1996and 1997 Addenda) and ISTC-3600 (1998 Edition with the 1999 and 2000 Addenda). In addition, licensees who continue to implement Section XI of the ASME BPV Code as their Code of Record may use OMN-1 in lieu of the provisions for stroke-time testing specified in Paragraph 4.2.1 of ASME/ANSI OM Part 10 as required by 10 CFR 50.55a(b)(2)(vii) subject to the conditions in this regulatory guide. Licensees who choose to apply OMN-1 must apply all its provisions.(1) The adequacy of the diagnostic test interval for eachmotor-operated valve (MOV) must be evaluated and adjusted as necessary, but not later than 5 years or three refueling outages (whichever is longer) from initial implementation of OMN-1.(2) When extending exercise test intervals for high risk MOVsbeyond a quarterly frequency, licensees must ensure that the potential increase in Core Damage Frequency (CDF) and risk associated with the extension is small and consistent with the intent of the Commission's Safety Goal Policy Statement. (3) When applying risk insights as part of the implementationof OMN-1, licensees must categorize MOVs according to their safety significance using the methodology described in Code Case OMN-3, "Requirements for Safety Significance Categorization of Components Using Risk Insights for Inservice Testing of LWR Power Plants," with the conditions discussed in this regulatory guide or use other MOV risk-ranking methodologies accepted by the NRC on a plant-specific or industry-wide basis with the conditions in the applicable safety evaluations.NOTE: As indicated at 64 FR 51370-51386, licensees arecautioned that, when implementing OMN-1, the benefits of performing a particular test should be balanced against the potential adverse effects placed on the valves or systems caused by this testing.OMN-3, Rev.
0Requirements for Safety Significance Categorization of ComponentsUsing Risk Insights for Inservice Testing of LWR Power Plants New 1998E CODE CASENUMBERTABLE 2, CONDITIONALLY ACCEPTABLE OM CODE CASESEDITION/ADDEND ACONDITION 2 The Code Case methodology for risk ranking uses two categories of safety significance. The NRC staffhas determined that this is acceptable for ranking MOVs, air-operated valves (AOVs), and check valves. However, the NRC staff has accepted other methodologies for risk ranking MOVs, with certain conditions and limitations, that use three categories of safety signficance.
7The following modifications apply when implementing CodeCase OMN-3 of the OM Code, 1995 Edition with the 1996
Addenda:(1) In addition to those components identified in the ASME ISTProgram Plan, implementation of Section 1, "Applicability," of the Code Case must include within the scope of a licensee's risk-informed IST program non-ASME Code components categorized 2 as high safety significant components (HSSCs)that might not currently be included in the IST Program Plan.(2) The decision criteria discussed in Section 4.4.1, "DecisionCriteria," of the Code Case for evaluating the acceptability of aggregate risk effects (i.e., for Core Damage Frequency [CDF]
and Large Early Release Frequency [LERF]) must be consistent with the guidance provided in Regulatory Guide 1.174, "An Approach for Using Probabilistic Risk Assessment in Risk-Informed Decisions on Plant-Specific Changes to the Licensing Basis."(3) Section 4.4.4, "Defense in Depth," and Section 4.4.5,"Safety Margins," of the Code Case must be consistent with the guidance contained in Sections 2.2.1, "Defense-in-Depth Evaluation," and 2.2.2, "Safety Margin Evaluation," of Regulatory Guide 1.175, "An Approach for Plant-Specific, Risk-Informed Decisionmaking: Inservice Testing."
CODE CASENUMBERTABLE 2, CONDITIONALLY ACCEPTABLE OM CODE CASESEDITION/ADDEND ACONDITION 8OMN-3, Rev.
0 (Cont'd)Requirements for Safety Significance Categorization of ComponentsUsing Risk Insights for Inservice Testing of LWR Power Plants New 1998E(4) Implementation of Sections 4.5, "Inservice TestingProgram," and 4.6, "Performance Monitoring," of the Code Case must be consistent with the guidance pertaining to inservice testing of pumps and valves provided in Section 3.2, "Program Implementation," and Section 3.3, "Performance Monitoring," of Regulatory Guide 1.175. Testing and performance monitoring of individual components must be performed as specified in the risk-informed components Code Cases (e.g., OMN-1, OMN-4, OMN-7, and OMN-12, as modified by the conditions discussed in this regulatory guide).
[Note: Conditions are consistent with established regulatory position.]OMN-4, Rev.
0Requirements for Risk Insights for Inservice Testing of CheckValves at LWR Power Plants New 1999AThe following modifications apply when implementing AppendixII, "Check Valve Condition Monitoring Program," of the OM Code, 1995 Edition with the 1996 Addenda:(1) Valve opening and closing functions must be demonstratedwhen flow testing or examination methods (nonintrusive, or disassembly and inspection) are used.(2) The initial interval for tests and associated examinationsmay not exceed two fuel cycles or 3 years, whichever is longer; any extension of this interval may not exceed one fuel cycle per extension with the maximum interval not to exceed 10 years. Trending and evaluation of existing data must be used to reduce or extend the time interval between tests.(3) If the Appendix II condition monitoring program isdiscontinued, the requirements of ISTC 4.5.1, "Exercising Test Frequency," through ISTC 4.5.4, "Valve Obturator Movement,"
must be implemented. [Note: Conditions are contained in 10 CFR 50.55a.]
CODE CASENUMBERTABLE 2, CONDITIONALLY ACCEPTABLE OM CODE CASESEDITION/ADDEND ACONDITION 9OMN-9, Rev.
0Use of a Pump Curve for Testing New 2000ALicensees may use Code Case OMN-9, Rev. 0, in lieu of theprovisions of ISTB 4.3, 4.4, 4.5, 5.2, and 6.1 of the OM Code, 1990 Edition up to and including the 1992 Addenda provided that:(1) When a reference curve may have been affected by repair,replacement, or routine servicing of a pump, a new reference curve must be determined, or an existing reference curve must be reconfirmed, in accordance with Section 3 of this Code
Case.(2) If it is necessary or desirable, for some reason other thanthat stated in Section 4 of this Code Case, to establish an additional reference curve or set of curves, these new curves must be determined in accordance with Section 3.OMN-11,Rev. 0Motor Operated Valve Risk-Based Inspection Code Case New 2001EWhere a licensee is implementing Code Case OMN-1 as ajustified alternative to the requirements for stroke-time testing of motor-operated valves (MOVs) in Subsection ISTC of the ASME OM Code, the licensee may apply risk insights to its MOV program as indicated in Paragraph 3.7, "Risk Based Criteria for MOV Testing," of OMN-1 and as supplemented by Code Case OMN-11 with the following conditions:(1) In addition to the Inservice Testing provisions ofParagraph 3 of OMN-11, MOVs within the scope of OMN-1 that are categorized as Low Safety Significant Components (LSSCs) must satisfy the other provisions of OMN-1, including determination of proper MOV test intervals as specified in Paragraph 6 of OMN-1.(2) Paragraph 3.1 of OMN-11 must be interpreted as allowingthe provisions of Paragraphs 3.5(a) and (d) of OMN-1 related to similarity and test sample, respectively, to be relaxed for the grouping of LSSC MOVs. The provisions of Paragraphs 3.5(b),
(c), and (e) of OMN-1, related to evaluation of test results for MOVs in the group, sequential testing of a representative MOV, and analysis of test results per Paragraph 6 of OMN-1 for each MOV in the group, respectively, continue to be applicable to all MOVs within the scope of OMN-1.OMN-11,Rev 0Motor Operated Valve Risk-Based Inspection Code Case New 2000E CODE CASENUMBERTABLE 2, CONDITIONALLY ACCEPTABLE OM CODE CASESEDITION/ADDEND ACONDITION 10(3) When extending exercise test intervals for high risk MOVsbeyond a quarterly frequency, the licensee must ensure that the potential increase in CDF and risk associated with the extension is small and consistent with the intent of the Commission's Safety Goal Policy Statement.[Note 1: conditions consistent with established regulatoryposition.] [Note 2: condition regarding allowable methodologies for MOV risk ranking specified for the use of OMN-1 also applies to OMN-11.]OMN-12,Rev. 0Alternative Requirements for Inservice Testing Using Risk Insightsfor Pneumatically- and Hydraulically-Operated Valve Assemblies in Light-Water Reactor Power Plants, OM Code 1998, Subsection ISTC New 2001E(1) Paragraph 4200, "Inservice Test Requirements," ofOMN-12 specifies inservice test requirements for pneumatically and hydraulically operated valve assemblies categorized as high safety significant within the scope of the Code Case. The inservice testing program must include a mix of static and dynamic valve assembly performance testing. The mix of valve assembly performance testing may be altered when justified by an engineering evaluation of test data.(2) Paragraph 4223 of OMN-12 specifies the periodic testrequirements for pneumatically and hydraulically operated valve assemblies categorized as high safety significant within the scope of the code case. The adequacy of the diagnostic test interval for each high safety significant valve assembly must be evaluated and adjusted as necessary, but not later than 5 years or three refueling outages (whichever is longer) from initial implementation of OMN-12.
CODE CASENUMBERTABLE 2, CONDITIONALLY ACCEPTABLE OM CODE CASESEDITION/ADDEND ACONDITION 11OMN-12,Rev. 0 (cont'd)Alternative Requirements for Inservice Testing Using Risk Insightsfor Pneumatically- and Hydraulically-Operated Valve Assemblies in Light-Water Reactor Power Plants, OM Code 1998, Subsection ISTC New 2001E(3) Paragraph 4230, "Periodic Valve Assembly Exercising," ofOMN-12 specifies periodic exercising for pneumatically and hydraulically operated valve assemblies categorized as high safety significant within the scope of the code case.
Consistent with the requirement in OMN-3 to evaluate the aggregate change in risk associated with changes in test strategies, when extending exercise test intervals for high safety significant valve assemblies beyond a quarterly frequency, the potential increase in Core Damage Frequency (CDF) and risk associated with the extension must be evaluated and determined to be small and consistent with the intent of the Commission's Safety Goal Policy Statement.(4) Paragraph 4410, "Acceptance Criteria," of OMN-12specifies that acceptance criteria must be established for the analysis of test data for pneumatically and hydraulically operated valve assemblies categorized as high safety significant within the scope of the code case. When establishing these acceptance criteria, the potential degradation rate and available capability margin for each valve assembly must be evaluated and determined to provide assurance that the valve assemblies are capable of performing their design-basis functions until the next scheduled test.(5) Paragraph 5000, "Low Safety Significant ValveAssemblies," of OMN-12 specifies that the purpose of its provisions is to provide a high degree of confidence that pneumatically and hydraulically operated valve assemblies categorized as low safety significant within the scope of the code case will perform their intended safety function if called upon. Low safety significant valve assemblies must be determined to be capable of performing their intended design-basis safety functions until the next scheduled test. The test and evaluation methods may be less rigorous than those applied to high safety significant valve assemblies.
CODE CASENUMBERTABLE 2, CONDITIONALLY ACCEPTABLE OM CODE CASESEDITION/ADDEND ACONDITION 12OMN-12,Rev. 0 (cont'd)Alternative Requirements for Inservice Testing Using Risk Insightsfor Pneumatically- and Hydraulically-Operated Valve Assemblies in Light-Water Reactor Power Plants, OM Code 1998, Subsection ISTC New 2001E(6) Paragraph 5100, "Set Points and/or Critical Parameters," ofOMN-12 specifies requirements and guidance for establishing set points and critical parameters of pneumatically and hydraulically operated valve assemblies categorized as low safety significant within the scope of the code case. Setpoints for these valve assemblies must be based on direct dynamic test information, a test-based methodology, or grouping with dynamically tested valves, and documented according to Paragraph 5140. The setpoint justification methods may be less rigorous than provided for high risk significant valve
assemblies.(7) Paragraph 5400, "Evaluations," of OMN-12 specifiesevaluations to be performed of pneumatically and hydraulically operated valve assemblies categorized as low safety significant within the scope of the code case. Initial and periodic diagnostic testing must be performed to establish and verify the setpoints of these valve assemblies to ensure that they are capable of performing their design-basis safety functions. Methods for testing and establishing test frequencies may be less rigorous than applied to high risk significant valve assemblies.(8) Paragraph 5600, "Corrective Action," of OMN-12 specifiesthat corrective action must be initiated if the parameters monitored and evaluated for pneumatically and hydraulically operated valve assemblies categorized as low safety significant within the scope of the code case do not meet the established criteria. Further, if the valve assembly does not satisfy its acceptance criteria, the operability of the valve assembly must be evaluated.[Note 1: Conditions are consistent with established regulatoryposition.] [Note: Licensees are cautioned that, when implementing OMN-12, the benefits of performing a particular test should be balanced against the potential adverse effects placed on the valves or systems caused by this testing.]
13Appendix AOperation and Maintenance Code Cases Publication InformationCODE CASENUMBEREDITION/ADDENDADATEOMN-11999 AddendaJuly 1, 1999OMN-21998 EditionJuly 1, 1998 OMN-31998 EditionJuly 1, 1998 OMN-41999 AddendaJuly 1, 1999 OMN-51999 AddendaJuly 1, 1999 OMN-61999 AddendaJuly 1, 1999 OMN-72000 AddendaJuly 1, 2000 OMN-82000 AddendaJuly 1, 2000 OMN-92000 AddendaJuly 1, 2000 OMN-102000 AddendaJuly 1, 2000 OMN-112001 EditionJuly 1, 2001 OMN-122001 EditionJuly 1, 2001 OMN-132001 EditionJuly 1, 2001 1 Code Case is unacceptable for use; See Draft Regulatory Guide DG-1112.
14Appendix BNumerical Listing of Operation and Maintenance Code CasesOMN-1OMN-2 OMN-3 OMN-4 OMN-5 OMN-6 OMN-7 OMN-8 OMN-9 OMN-10 1OMN-11 OMN-12 OMN-13 15DRAFT IMPACT STATEMENTA draft impact statement has been prepared for the publication for publiccomment for proposed revisions to Regulatory Guides 1.84, "Design and Fabrication Code Case Acceptability, ASME Section III" (DG-1090), and 1.147, "Inservice Inspection Code Case Acceptability, ASME Section XI, Division 1," and one proposed regulatory guide. The proposed Revision 32 of Regulatory Guide 1.84 will combine Regulatory Guides 1.84 and 1.85. The new proposed guide is DG-1089, "Operation and Maintenance Code Case Acceptability, ASME OM Code."ASME Code Cases provide alternatives to existing requirements contained in theASME BPV and OM Codes, which have already been incorporated by reference into 10 CFR 50.55a. Hence, the inservice examinations and inservice testing provisions incorporated into 10 CFR 50.55a are currently being performed by licensees. Use of these alternatives, therefore, does not result in associated installation or continuing costs. In addition, since many Code Cases provide more efficient and effective examinations and tests or were developed for the purpose of reducing occupational exposure, the implementation of Code Cases reduces the burden on industry.A copy of the Draft Impact Statement is available for inspection or copying for afee in the NRC's Public Document Room at 11555 Rockville Pike, Rockville, MD. The PDR's mailing address is USNRC PDR, Washington, DC 20555; telephone (301)415-4737 or 1-(800)397-4209; fax (301)415-3548; e-mail <PDR@NRC.GOV> . The DraftImpact Statement is also available through the NRC's Electronic Reading Room under accession number ML012690636.