ML20030B097
| ML20030B097 | |
| Person / Time | |
|---|---|
| Issue date: | 07/31/1981 |
| From: | NRC OFFICE OF NUCLEAR REGULATORY RESEARCH (RES) |
| To: | |
| References | |
| TASK-FP-026-5, TASK-FP-26-5, TASK-OS REGGD-03.047, REGGD-3.047, NUDOCS 8108050432 | |
| Download: ML20030B097 (3) | |
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U.S. NUCLEAR REGULATOldt CEMMISSION July 1981 A
W,;s REGULATORY GUI
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L fl REGULATORY GUIDE 3.47 U h[U L,lI L J y
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NUCLEAR CRITICALITY CONTROi. AND SAFETY OF HOMOGENitQ Sv.s.togcl3[h PLUTONIUM-URANIUM FUEL MIXTURES OUTSIDE REACTOR \\
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moderation, and tabulated subcritical c- % r yoj%h A. INTRODUCTION for plutonium in homogeneous mixtures of p d
Section 7a22, " Contents of applications," of 10CFR natural uranium of unlimited mass. Caution in the use of Part 70, " Domestic Licensing of Special Nuclear Material,"
the suberitical limits in the standard is advised in establish-requires that applications for a specific license to own, ing process specifications since the suberiticallimits do not acquire, deliver, receive, possess, use, or transfer special contain margins for contingencies such as double batching nuclear material contain, among other things, proposed or inaccuracy of analytical techniques. The limits of the procedures to avoid accidentalconditiensof criticality.This standard are not applicable to heterogeneous systems. Also, regulatory guide provides guidance for complying with this the standard does not include the details of administrative portion of the Commission's regulations by describing controls, the design of processes or equipment, the descrip-procedures acceptable to the NRC staff for the prevention tion of instrumentation for process control, or detailed of criticality accidents in operations involving homogeneous criteria to be met in transporting fissionable materials.
plutonium-uranium fuel mixtures outside reactors.
B. DISCUSSION C. REGULATORY POSITION ANSI /ANS 8.12-1978, " Nuclear Criticality Control and The maximum subcritical limits for operations involving Safety of Ilomogeneous Plutonium-Uranium Fuel Mixtures homogeneous mixtures of plutonium and uranium outside Outside Reactors,"3 was prepared by Subcommittee 8, Fission-reactors contained in ANSI /ANS 8.12-1978 are acceptable able Materials Outside Reactors,of the Standards Committee to the NRC staff when allconditions of ANSI /ANS 8.12-1978 of the American Nuclear Society. ANSI /ANS 8.121978 was are satisfied.
approved by the American 14ational Standards Committee l
N16, Nuclear Criticality Safety, in 1977 and subsequently l
by the American National Standards Institute (ANSI) on Section 6 of ANSI /ANS 8.12-1978 lists additional docu-l July 17,1978.
ments referred to in the standard. The specific applicability l
or acceptability of two of these listed documents has been l
ANSI /ANS 8.12-1978 providesguidance for the prevention addressed in the latest version of the regulatory guides of criticality accidents in operations with homogeneous identified below:
plutonium-uranium fuel mixtures outside reactors. The standard applies to operations involving homogeneous plutonium-uranium fuel mixtures containing no more than Standard' Regulatory Guide 30 wt 'T, plutonium combined with uranium containing no more than 0.71 wt-7o U-235.The standard presents tabulated subcritical limits and graphs for uniform aqueous mixtures ANSI N16.1-1975 3.4 - Nuclear Criticality Safety in of the oxides of plutonium and natural uranium, tabulated Operations with Fissionable i
subcritical mass limits for single units of homogeneously Materials Outside Reactors mixed oxides of plutonium and natural uranium at low l
ANSI N16.9-1975 3.41 - Validation of Calculational I
Methods for NuclearCriti-Copies may be sbtained from the American Nuclear Society, 555 North Kensington Avenue, LaGrange Park, Illinois 60525.
cality Safety i
E H
Q O Q USNRC REGULATORY GUIDES Comments should be sent to the Secretary of the Commission, tN U.S. Nuclear Regulatory Commission, Washin,) ton, D.C. 205 5 5, Q
Regulatory Guides are issued to describe and make available to the Attention: Docketing and Service Branch, w
pu blic met h ods acceptable to the NRC staf f of implementing g
sgaecific parts of the Commission's regulations, to delineate tech-The guides are issued in the following ten broad divisions:
niques used by the staff in evaluating specific problems or postu-lit ed accidents, or to provide guidance to applicants. Regulatory
- 1. Power Reactors
- 6. Products pd Guedes are not substitutes for regulations, and compliance with
- 2. Research and Test Reactors
- 7. Transportation gQ the - 15 not required. Methods and solutions dif ferent from those set
- 3. Fuels and Materials Facilities
- 8. Occupational Health ggg out in the guides will De acceptable if they provide a basis for the
- 4. Environmental and Siting
- 9. Antstrust and Financial Review 00 findings requisite to tne issuance or continuance of a permit or
- s. Materials and Plant Protection 10. General license by the Commission.
MD Cop J5 of hsued guides may be purchased at the current Government 00 @ Tnis guide was issued af ter consideration of comments received from m 'Q tne public. comments and sugaestions for improvements in these Printing Of fice price. A subscription service for future guides in spe-Cific divisions is ava*lable through the Government Printing Of fice.
OE. guides are encouraged at all t.mes, and guides will be revised, as information on the subscription service and current GPO prices may gg a poropriate, to accommodate comments and to reflect new informa-be obtained by writing the U.S. Nuclear Regulatory Commission, un r merience.
wasningt n, n 20sss, Attenuon PuWcauons Sales Managen CD O O
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D. IMPLEMENTATION approach to criticality safety in operations involving homogeneous plutonium-uranium fuel mixtures outside
. The purpose of this section is to provide information to.
reactors. Therefore, except in those cases in which the applicants regarding the NRC staff's pl.ns for using this applicant proposes an acceptable alternative method for regulatory guide, complying with specified portions of the Commission's regulations, the method described herein will be used after I
The methods described in this guide were applied in a the issuance of this guide in the evaluation of submittals number of specific cases during reviews and selected licens,
i; ing actions. These methods reflect the latest general NRC ~
for license applications submitted pursuant to 10 CFR Part 70.
r.
VALUE/ IMPACT STATEMENT I,
The NRC staff performed a value/ impact assessment to tures Outside Reactors." The results of this assessment determine the proper procedural approach for providing were included in a draft regulatory guide on this subject guidance on the prevention of criticality accidents in opera-that was issued for public comment in December 1980. A tions involving homogeneous plutonium-uranium fuel copy of this draft guide and the associated value/ impact mixtures outside reactors. This assessment resulted in a statement (identified by its task number, FP 026-5) is decision to develop a regulatory guide that would eadorse available for inspection and copying for a fee at the Com-ANSI /ANS 8.12-1978, " Nuclear Criticality Control and mission's Public Document Room at 1717 11 Street NW.,
Safety of Ilomogeneous Plutonium-Uranium Fuel Mix.
Washington, D.C.
- U s. GovERNME NT PRINTING OFFICE: 1981-341J421186 l
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- m UNITED STATES NUCLEAR REGULATOQV COMMISSION W ASHIN GTON, D. C. 20555
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