Regulatory Guide 1.51
| ML13350A361 | |
| Person / Time | |
|---|---|
| Issue date: | 05/31/1973 |
| From: | US Atomic Energy Commission (AEC) |
| To: | |
| References | |
| RG-1.051 | |
| Download: ML13350A361 (2) | |
4"'*1*.(L.4`U.S. ATOMIC ENERGY COMMISSIONR GULATORYDIRECTORATE OF REGULATORY STANDARDSMay 1973GUIDEINSEFREGULATORY GUIDE 1.51IVICE INSPECTION OF ASME CODE CLASS 2AND 3 NUCLEAR POW
A. INTRODUCTION
General Design Criteria 36. "Inspection ofEmergency Core Cooling System." 39. "Inspection ofContainment Heat Removal System." 42, "Inspection ofContainment Atmosphere Cleanup Systems," and 45."Inspection of Cooling Water System," of Appendix Ato 10 CFR Part 50. "Generzl Desian Criteria for NuclearPower Plants," require that the subject systems bedesigned to permit appropriate periodic inspection ofimportant component parts of the systems to assuresystem integrity and capability. Regulatory Guide 1.26(Safety Giuide 26). "Quality Group Classification andStandards," in conjunction with § 50.55a of 10 CFRPart 50 describes a quality classification system relatedto specified industry codes that may be used todetermine quality standards for water- andsteam-containing components important to the safety ofwater-cooled nuclear power plants. This guide describesacceptable methods of implementing the periodicinservice inspection requirements for American Societyof Mechanical Engineers (ASME) Code Class 2 and 3components. This guide applies to light-water-cooledreactors. The Advisory Committee on ReactorSafeguards has been consulted concerning this guide andhas concurred in the regulatory position.
B. DISCUSSION
The ASME Boiler and Pressure Vessel Code (ASMEB&PV Code),Section XI, "Rules for InserviceInspection of Nuclear Reactor Systems."' specifiesrequirements for ilservice inspection of Code Class 12'Copies may he obtained from American Society ofMechanical Enqincers. United Engineering Center, 345 Ea'st 47thStreet, New York, N.Y. 100 17.IC6mponents classified as AEC Quality Group A. B, and Cshould conform to the requirements of the ASSlI' Boiler andPressure Vessel Code for Class I. 2. and 3 components,resp ctively.TER PLANT COMPONENTScomponen ts. In the Winter 1972 Addenda to SectionXI,3 acceptable inservice inspection requirements arespecified for Code Class 22 components. Code Class 32components are not presently included in Section X1requirements, but they should also be part of thescheduled inservice inspection program. The inspectionrequirements need not be as extensive as those requiredfor Code Class 2 components but should, as a minimum.include visual inspection of Code Class 3 componentband their supports. For such inspections to be effective.they should be performed at periods when thecomponents are under pressure of sutficienti nagnitudeto properly represent the intended service condition.This may require that the inspections of Code Class 'components be scheduled to coincide with systemperformance tests, component functional tests, andsystem pressure tests in order to benefit from thepressure levels established for these tests. Section XIdefines an inspection interval for Code Class I and 2components as 10 years, and the inservice inspectionprogram for Code Class 3 components should be basedon the same time interval.Code Class 3 components required to functionduring normal reactor operation would generally heaccessible during reactor downtime, and they should beinspected at least once toward the end ot eachinspection interval. Components in systems or portiovriof systems which are not required to futiction duringreactor operation can be inspected independently ofreactor downtime.The visual inspection of Code Class 3 componentsshould be conducted for signs or evidence of leak.:'ccaused by structural distress or corrosion effects on the,components. In addition, supports and hangers liltpiping and Code Class 3 componenls over 4 inches illdianicter should be inspected for evidence of inadcqmtmsupport, unintended restrmint. or structur:al distress."ASME B&PV Code, Sectiotni Xl. Wintter 1972 Addtenda.USAEC REGULATORY GUIDES Copies of publiihed guide% may be obtained by es.luftl indicating the div~iun;desired to the US. Atomic Energy Cumr,$,s.on. Washtrinton. DZ.. 2CS4t.Regulatory Guides are issued /o describe and ,'r1te available lt. the public Attention: Director of negulatnry Stsnd3ordi. Coermtnts , I-itethods acceptbhle to the AEC Rl'gulatory stifl of imnplemrnting specific pants of imirovemlrts in htfe gklir Mi enc)ur'ed and should be %tnt to ite SetjPrithe Comminsion's tegulisions, to dielinete uStit by 9.- staff in of the U.S. Alomic Enetriv Cunmmostun. Vlh.hirigit.. D.C. 20U-45.e'llualtng specific problems or pOstulated at to provide gait'enco in Attention: Chief. Pubic Proceedings Sliit.applicants. Regulatory Guides ere not substitutes for 'eguitiuni And compliancewith them it not requirad. Methodt and differont frmt ihoos %st out in The guides are issued in the follosring ton brail drisic.ni:the guides wvill be acceputable if they provide a batis far tim finrdmtlt reQuitl-l tothe i muan tce ot continuance of a it of Icente by the Com m ,ssion. 2. R eIe ref end T itw* Re tcto t 7. T srini rtniin3. Fuels anor M4teiitis FaitIlt," .HeaslthPublihhed guiders will be revised periodicull,. at apOraOrtipr., to accomnodate 4. Environtat.rll am Sam)t', 9. Antitrust Revieweproetients and to reflect new infoorntatOn of experience. S. Materitls &nd Plant Protection 1
0. General
'I,The pressure developed in components during asystem performance lest, a component performance test,or a system pressure test should be representative ofconditions under which the systems should be leaktightduring operation. The lest pressure should be at least110 percent of the system design pressure. However. thepressure developed during the conduct of a periodicsystem performance test would be acceptable duringinspections conducted in periods between the pressuretests. Certain components. such as open storage tanksincluding piping to the first shutoff valve, cannot readilybe pressure tested. The hydrostatic pressure developedwith tanks filled to their design capacity would be anacceptable test pressure for such tanks and connectedpiping.
C. REGULATORY POSITION
I. Inservice inspection requirements for ASME CodeClass 22 components should comply with the ASMEB&PV Code. Section X1 and the Winter 1972 Addenda'for Class 2 components except that subparagraphISC-261(a) should be changed to read as follows:"Components in systems or portions of systemswhich recirculate reactor coolant during normalreactor operation, and are designed for pressure andtempcrature in excess of either 275 psig or 200°Fshall be examined in accordance with therequirements specified in Table ISC-261 ."2. Inspection programs for ASME Code Class 32components should be performed according to thefollowing schedules:a. All of the components should be pressureIttested and inspected at least once during each 10-yearinspection interval.b. In addition, all components should be inspectedduring periods of normal reactor operation or duringsystem performance testing at least once during everyone-third of each inspection interval.3. Inspection requirements for ASME Code Class 3components should include the following:a. System pressure tests should be performed tothe extent necessary to perform the componentexamination. Test pressure should be at least:(1) For closed systems, 110 percent of thedesign pressure.(2) For open storage tanks, the nominalhydrostatic pressure developed with the tanks filled todesign capacity.(3) Open-ended portions of systems may beexempted from pressure testing.b. Visual inspections for evidence of unanticipatedcomponent leakage, structural distress. or corrosion.c. Inspection of supports and hangers for pipingand components over 4 inches in diameter for evidenceof inadequate support, unintended restraint, orstrurtural distress.4. Records of the inserice inspection should beestablished and maintained for the life of the plant andshould include:a. Identification of systems componentsinspected;b. Date of inspection;c. Repair or replacement; andd. Signature of employee certifying dte inspectionwas made.1.5 1-2