Regulatory Guide 5.1
| ML12191A014 | |
| Person / Time | |
|---|---|
| Issue date: | 12/31/1972 |
| From: | Office of Nuclear Regulatory Research |
| To: | |
| References | |
| RG-5.001 | |
| Download: ML12191A014 (4) | |
12/20/72U.S. ATOMIC ENERGY COMMISSIONREGULATORYDIRECTORATE OF REGULATORY STANDARDSGUIDEREGULATORY GUIDE 5.1SERIAL NUMBERING OF FUEL ASSEMBLIES FOR LIGHT-WATER-COOLEDNUCLEAR POWER REACTORS
A. INTRODUCTION
Part 70 of the Atomic Energy Commission'sregulations requires that certain licensees establish andmaintain written material control and accountingprocedures which are sufficient to enable the licensee toaccount for the special nuclear material (SNM) in hispossession. In the case of SNM contained in fuelassemblies, a system of control based on unique itemidentification of each fuel assembly is desirable toachieve an acceptable level of accountability control.This guide describes an acceptable numbering methodfor item identification of fuel assemblies forlight-water-cooled nuclear power reactors.
B. DISCUSSION
Power reactor fuel is relatively inaccessible while ata reactor facility. The SNM itself is securely containedwithin the fuel cladding. Accurate quantitativemeasurements of the SNM content of the fuel assembliesare exceedingly difficult, and as yet not feasible exceptthrough use of techniques requiring disassembly intoindividual fuel rods. The SNM content of a fuel assemblyis currently obtained by determining the SNM content ineach discrete item (element or rod), and then verifyingthe presence of such items. The principal diversionthreat for SNM at the reactor consists of theft ofidentifiable items. Accordingly, the AEC's materialprotection inspection practices for SNM contained incompleted fuel assemblies on inventory at light-waterreactor facilities are based on assuring that allindividually identifiable fuel pieces received at thefacility are still on hand or have been shipped to otherlicensed facilities.A substantial level of assurance can be providedwithin this context if each fuel assembly is uniquelyidentified by a number inscribed in its structure. Theunique numbering also offers an advantage at the time ofreprocessing in that fuel assemblies can be readilyidentified according to origin and irradiation history,thus avoiding confusion in formation of dissolverbatches.The Fuel Assembly Identification Working Group ofSubcommittee ANS-13, Fuel Assembly Criteria, hasdeveloped a standard (ANS 13.8) for fuel assemblyidentification. This standard was approved by theAmerican National Standards Institute as N18.3-1972!on May 10, 1972.Some fabricators purposely manufacture fuelassemblies that can be dismantled without anymetal-cutting operation. This design feature allowsrelatively easy substitution of fuel rods, but complicatesthe verification of discrete power reactor fuel items.
C. REGULATORY POSITION
1. The provisions contained in ANSI N18.3-1972,"Fuel Assembly Identification," are generally acceptableand provide an adequate numbering basis foridentification of individual fuel assemblies from the timeof final fuel rod consolidation at the fabricator's facilityuntil the assembly is dissolved as an entity.2. In the special case of fuel assemblies from which afuel rod or other SNM-containing component may beremoved without the need of a metal-cutting operation,further identification and accounting measures inaddition to those required in ANSI N18.3-1972 may benecessary. This determination will be made on anindividual case basis.'Copies may be obtained from the American NationalStandards Institute, Inc., 1430 Broadway, New York. New York10018.USAEC REGULATORY GUIDES Copies of published guides may be obtained by request indicating the divisionsdesired to the US. Atomic Energy Commission, Washington, D.C. 20545,Regulatory Guides are issued to describe and make available to the public Attention: Director of Regulatory Standards. Comments and suggestions formethods acceptable to the AEC Regulatory staff of Implementing specific parts of improvements In these guides are encouraged and should be sent to the Secretarythe Commission's regulations, to delineate techniques used by the staff in of the Commission, U.S. Atomic Energy Commission, Washington, D.C. 20545.evaluating specific problems or postulated accidents, or to provide guidance to Attention: Chief, Public Proceedings Staff.applicants. Regulatory Guides are not substitutes for regulations and compliancewith them Is not required. Methods and solutions different from those set out in The guides ere issued in the following ten broad divisions:the guides will be acceptable if they provide a basil for the findings requisite tothe Issuance or continuance of a permit or license by the Commission. 1. Power Reactors 8. Products2. Reaeerch end Test Reactors 7. Transportation3. Fuels and Materials Facilities 8. Occupational HealthPublished guides will be revised periodically, as appr.,rwate, to accommodate 4. Environmental and Siting 9. Antitrust Reviewcomments and to reflect new information or experience. 5. Materials and Plant Protection 1
0. General