Regulatory Guide 8.12
| ML12220A072 | |
| Person / Time | |
|---|---|
| Issue date: | 10/31/1988 |
| Revision: | 0 |
| From: | Office of Nuclear Regulatory Research |
| To: | |
| References | |
| CE 801-5 RG-8.012, Rev. 2 | |
| Download: ML12220A072 (3) | |
Revision 2PI, REG, o U.S. NUCLEAR REGULATORY COMMISSION October 1988REGULATORY GUIDE'**e OFFICE OF NUCLEAR REGULATORY RESEARCH /7 I ! AREGULATORY GUIDE 8.12(Task CE 801-5)CRITICALITY ACCIDENT ALARM SYSTEMSA. INTRODUCTIONSection 70.24, "Criticality Accident Requirements," of10 CFR Part 70, "Domestic Licensing of Special NuclearMaterial," requires licensees who are authorized to possessspecial nuclear material in excess of certain amounts tomaintain a criticality accident alarm system. This guidedescribes a system acceptable to the NRC staff for meetingthe Commission's requirements for a criticality accidentalarm system.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. DISCUSSIONSection 70.24 requires, in part, a monitoring systemcapable of detecting a criticality that produces an absorbeddose in soft tissue of 20 rads of combined neutron andgamma radiation at an unshielded distance of 2 meters fromthe reacting material within 1 minute. Criticality accidentalarm systems are also discussed in American NationalStandard ANSI/ANS-8.3-1986, "Criticality Accident AlarmSystem,"1 which has the same detection criterion.C. REGULATORY POSITIONThe guidance on criticality accident alarm systemscontained in ANSI/ANS-8.3-1986, "Criticality AccidentlCopies may be obtained from the American Nuclear Soci-ety, 555 North Kensington Avenue, La Grange Park, Illinois 60525.Alarm System," is generally acceptable tosubject to the following limitations:1. Section 70.24 of 10 CFR Part 70 requires alarmcoverage "in each area in which such licensed specialnuclear material is handled, used, or stored ... ," whereasparagraph 4.2.1 of the standard states that the need forcriticality alarms must be evaluated for such areas. If suchan evaluation does not determine that a potential forcriticality exists, as for example where the quantities orform of special nuclear material make criticality practicallyimpossible or where geometric spacing is used to precludecriticality, such as in some storage spaces for unirradiatednuclear power plant fuel, it is appropriate to request anexemption from § 70.24.2. Paragraph 70.24(a)(1) of 10 CFR Part 70 requiresthat each area be covered by two detectors, whereas para-graph 4.5.1 of the standard permits coverage by a reliablesingle detector.D. IMPLEMENTATIONThe purpose of this section is to provide information toapplicants regarding the NRC staff's plans for using thisregulatory guide.Except in those cases in which an applicant proposes anacceptable alternative method for complying with § 70.24of 10 CFR Part 70, the method described in this guide willbe used in the evaluation of designs of criticality accidentalarm systems.USNRC REGULATORY GUIDES The guides are issued in the following ten broad divisions:Regulatory Guides are Issued to describe and make available to thepublic methods acceptable to the NRC staff of Implementing 1. Power Reactors 6. Productsspecific parts of the Commission's regulations, to delineate tech- 2. Research and Test Reactors 7. Transportationnlques used by the staff in evaluating specific problems or postu- 3. Fuels and Materials Facilities 8. Occupational Healthlated accidents or to provide guidance to applicants. Regulatory 4. Environmental and Siting 9. Antitrust and Financial ReviewGuides are not substitutes for regulations, and compliance with 5. Materials and Plant Protection 10. Generalthem 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 or Copies of issued guides may be purchased from the Governmentlicense by the Commission. Printing Office at the current GPO price. Information on currentGPO prices may be obtained by contacting the Superintendent ofThis guide was issued after consideration of comments received from Documents, U.S. Government Printing Office. Post Office Boxthe public. Comments and suggestions for improvements In these 37082, Washington, DC 20013-7082, telephone (202)275-2060 orguides are encouraged at all times, and guides will be revised, as (202)275-2171.appropriate, to accommodate comments and to reflect new informa-tion or experience.Issued guides may also be purchased from the National TechnicalWritten comments may be submitted to the Rules and Procedures Information Service on a standing order basis. Details on thisBranch, DRR, ADM, U.S. Nuclear Regulatory Commission, service may be obtained by writing NTIS, 5285 Port Royal Road,Washington, DC 20555. Springfield, VA 2216 VALUE/IMPACT STATEMENTA draft value/impact statement was published with the proposed Revision 2 to Regulatory Guide 8.12(Task CE 801-5) when the draft guide was published for public comment in May 1988. No changeswere necessary, so a separate value/impact statement for the final guide has not been prepared. A copyof the draft value/impact statement is available for inspection and copying for a fee at the Commission'sPublic Document Room at 2120 L Street NW., Washington, DC, under Task ('CF 801-5.8.12-2 UNITED STATESNUCLEAR REGULATORY COMMISSIONWASHINGTON. D.C. 20555OFFICIAL BUSINESSPENALTY FOR PRIVATE USE, $300FIRST CLASS MAILPOSTAGE b FEES PAIDUSNRCPERMIT No. G-67