Regulatory Guide 3.4

Nuclear Criticality Safety in Operations with Fissionable Materials at Fuels and Materials Facilities

ML12220A058
Person / Time
Issue date:	03/20/1986
From:	Minogue R B Office of Nuclear Regulatory Research
To:
References
CE 404-4 RG-3.004, Rev. 2
Download: ML12220A058 (5)

0wPM UNITED STATESNUCLEAR REGULATORY COMMISSION0 WASHINGTON, D.C. 20555March 20, 1986REGULATORY GUIDE DISTRIBUTION LIST (DIVISION 3)

SUBJECT: ISSUANCE OF REVISION 2 TO REGULATORY GUIDE 3.4 ANDWITHDRAWAL OF REGULATORY GUIDE 3.41With the issuance of Revision 2 to Regulatory Guide 3.4, "NuclearCriticality Safety in Operations with Fissionable Materials at Fuels andMaterials Facilities," the NRC staff is withdrawing Regulatory Guide 3.41,"Validation of Calculational Methods for Nuclear Criticality Safety."Revision 2 to Regulatory Guide 3.4 endorses ANSI/ANS-8.1-1983, "NuclearCriticality Safety in Operations with Fissionable Materials OutsideReactors," which is a consolidation of ANSI N16.1-1975/ANS-8.1 (endorsedby Revision 1 of Regulatory Guide 3.4) and ANSI N16.9-1975/ANS-8.11(endorsed by Regulatory Guide 3.41). Regulatory Guide 3.41 is thereforeobsolete. However, withdrawal of Regulatory Guide 3.41 is in no wayintended to alter any prior or existing licensing commitments based onits use.Regulatory guides may be withdrawn when they are superseded by theCommission's regulations, when equivalent recommendations have beenincorporated in applicable approved codes and standards, or when changesin methods and techniques or in the need for specific guidance have madethem obsolete.Robert B. Minogue, DirectorOffice of Nuclear Regulatory Research Revision 2 *March 1986U.S. NUCLEAR REGULATORY COMMISSIONREGULATORY GUIDEOFFICE OF NUCLEAR REGULATORY RESEARCHREGULATORY GUIDE 3A(Task CE 404-4)NUCLEAR CRITICALITY SAFETY IN OPERATIONS WITH FISSIONABLEMATERIALS AT FUELS AND MATERIALS FACILITIESA. INTRODUCTIONSection 70.22, "Contents of Applications," of 10 CFRPart 70, "Domestic Licensing of Special Nuclear Material,"requires that applications for a specific license to own,acquire, deliver, receive, possess, use, or initially transferspecial nuclear material contain proposed procedures toavoid accidental criticality. This guide describes proceduresacceptable to the NRC staff for preventing accidentalcriticality in operations with fissionable materials at fuelsand materials facilities (i.e., fuel cycle facilities otherthan nuclear reactors) and for validating calculationalmethods used in assessing nuclear criticality safety.Any information collection activities mentioned in thisregulatory guide are contained as requirements in 10 CFRPart 70, which provides the regulatory basis for this guide.The information collection requirements in 10 CFR Part 70have been cleared under OMB Clearance No. 3150-0009.B. DISCUSSIONANSI/ANS-8.1-1983, "Nuclear Criticality Safety inOperations with Fissionable Materials Outside Reactors,"**was prepared by Subcommittee 8, Fissionable MaterialsOutside Reactors, of the Standards Committee of theAmerican Nuclear Society as a consolidation of revisions toANSI N16.1-1975/ANS-8.1 and ANSI N16.9-1975/ANS-8.11.ANSI/ANS-8.1-1983 was approved by the AmericanNational Standards Committee N16, Nuclear CriticalitySafety,. in 1982 and by the American National StandardsInstitute (ANSI) on October 7, 1983.ANSI/ANS-8.1-1983 applies to handling, storing, proc-essing, and transporting fissionable material outside nuclear*Lines indicate substantive changes from Revision 1.**Copies may be obtained from the American Nuclear Society,555 North Kensington Avenue, La Grange Park, Illinois 60525.reactors. The standard presents generalized basic criteriaand specific limits (maximum subcritical) for some singleunits of simple shape containing 233U, 235U, 239pu,but not for multi-unit arrays. Further, the subcritical limitsspecified in the standard allow for uncertainties in thecalculations and experimental data used in their derivationbut not for contingencies such as double batching or failureof analytical techniques to yield accurate values.This standard also delineates requirements for estab-lishing the validity and area of applicability of a calcula-tional method used in assessing nuclear criticality safety.However, it is concerned only with validating calculationalmethods and does not address important related questionssuch as the margin of safety to be used with the method orthe qualifications of the personnel responsible for the datainput.This standard does not apply to the assembly of fission-able materials under controlled conditions, e.g., in criticalexperiments. Nor does the standard include the details ofadministrative controls, the design of processes or equip-ment, the description of instrumentation for processcontrol, or detailed criteria to be met in transportingmulti-unit arrays of fissionable materials.C. REGULATORY POSITIONThe nuclear criticality safety practices, the single-parameter limits for fissionable nuclides, and the guidancefor multiparameter control contained in ANSI/ANS-8.1-1983provide procedures acceptable to the NRC staff for pre-Iventing accidental conditions of criticality in handling,storing, processing, and transporting special nuclearmaterials at fuels and materials facilities. However, use ofANSI/ANS-8.1-1983 is not a substitute for detailed nuclearcriticality safety analyses for specific operations.The guidelines for validating calculational methods fornuclear criticality safety contained in ANSI/ANS-8.1-1983USNRC REGULATORY GUIDESRegulatory Guides are issued to describe and make available to thepublic methods acceptable to the NRC staff of implementingspecific parts of the Commission's regulations, to delineate tech-niques used by the staff in evaluating specific problems or postu-lated accidents, or to provide guidance to applicants. RegulatoryGuides are not substitutes for regulations, and compliance withthem is not required. Methods and solutions different from those setout In the guides will be acceptable if they provide a basis for thefindings requisite to the Issuance or continuance of a permit orlicense by the Commission.This guide was Issued after consideration of comments received fromthe public. Comments and suggestions for improvements in theseguides are encouraged at all times, and guides will be revised, asappropriate, to accommodate comments and to reflect new informa-tion or experience.Written comments may be submitted to the Rules and ProceduresBranch, DRR, ADM, U.S. Nuclear Regulatory Commission,Washington, DC 20555.The guides are Issued in the following ten broad divisions:1. Power Reactors 6. Products2. Research and Test Reactors 7. Transportation3. Fuels and Materials Facilities 8. Occupational Health4. Environmental and Siting 9. Antitrust and Financial Review5. Materials and Plant Protection 10. GeneralCopies of issued guides may be purchased from the GovernmentPrinting Office at the current GPO price. Information on currentGPO prices may be obtained by contacting the Superintendent ofDocuments, U.S. Government Printing Office, Post Office Box37082, Washington, DC 20013-7082, telephone (202)275-2060 or(202)275-2171.Issued guides may also be purchased from the National TechnicalInformation Service on a standing order basis. Details on thisservice may be obtained by writing NTIS, 5285 Port Royal Road,Springfield, VA 2216 provide a procedure acceptable to the NRC staff forestablishing the validity and area of applicability of cal-culational methods used in assessing nuclear criticalitysafety. However, it will not be sufficient merely to referto this guide in describing the validation of a method.The details of validation indicated in Section 4.3.6 ofthe standard should be provided to demonstrate theadequacy of the safety margins relative to the bias andcriticality parameters and to demonstrate that the cal-culations embrace the range of variables to which themethod will be applied.Section 7 of ANSI/ANS-8.1-1983 lists additional docu-ments referred to in the standard. Endorsement ofANSI/ANS-8.1-1983 by this regulatory guide does notconstitute an endorsement of these documents.D. IMPLEMENTATIONThe purpose of this section is to provide information toapplicants and licensees regarding the NRC staff's plans forusing this regulatory guide.The methods described in this guide were applied to anumber of specific cases during reviews and selected li-censing actions. These methods reflect the latest generalNRC approach to criticality safety in operations withfissionable materials at fuels and materials facilities. There-fore, except in those cases in which the applicant proposesan acceptable alternative method for complying withspecified portions of the Commission's regulations, themethods described in this guide will be used in the evaluationof submittals in connection with license applicationssubmitted under 10 CFR Part 70.3.4-2 VALUE/IMPACT STATEMENTThe NRC staff performed a value/impact assessment todetermine the proper procedural approach for updatingRevision 1 of Regulatory Guide 3.4, "Nuclear CriticalitySafety in Operations with Fissionable Materials OutsideReactors," issued in February 1978, which endorsedANSI N16.1-1975/ANS-8.1. The NRC staff has been in-volved in the development, review, and approval of a revisionto ANSI N16.1-1975/ANS-8.1 (designated ANSI/ANS-8.1-1983), which was approved by the AmericanNational Standards Institute on October 7, 1983. Theassessment resulted in a decision to develop a revision toRegulatory Guide 3.4 that would endorse, with possiblesupplemental provisions, ANSI/ ANS-8.1-1983. The resultsof this assessment were included in a proposed Revision 2to Regulatory Guide 3.4 that was issued for public commentin April 1985. No comments have been received from thepublic, and additional NRC staff review has shown that,except for minor clarifications, there was no need to changethe regulatory position of the proposed Revision 2 to Regu-latory Guide 3.4. Therefore, the value/impact statementpublished with the proposed revision is applicable. A copyof the draft regulatory guide and the associated value/impactstatement (identified by its task number, CE 404-4) isavailable for inspection or copying for a fee at the Com-mission's Public Document Room at 1717 H Street NW.,Washington, DC.3.4-3 UNITED STATESNUCLEAR REGULATORY COMMISSIONWASHINGTON, D.C. 20555OFFICIAL BUSINESSPENALTY FOR PRIVATE USE, $300FIRST CLASS MAILPOSTAGE fi FEES PAIDUSNRCPERMIT No. G-67UiSN RCjOHN RIDGEL32.'4 tNlLS27