Regulatory Guide 3.1

Use of Borosilicate-Glass Raschig Rings as a Neutron Absorber in Solutions of Fissile Material

ML12220A057
Person / Time
Issue date:	09/30/1987
From:	Office of Nuclear Regulatory Research
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References
CE 602-4 RG-3.001, Rev. 2
Download: ML12220A057 (4)

Revision 2 U.S. NUCLEAR REGULATORY COMMISSION September 1987 REGULATORY GUIDE

OFFICE OF NUCLEAR REGULATORY RESEARCH

REGULATORY GUIDE 3.1 (Task CE 602-4)

USE OF BOROSILICATE-GLASS RASCHIG RINGS AS A NEUTRON

ABSORBER IN SOLUTIONS OF FISSILE MATERIAL

A. INTRODUCTION

ANSI/ANS-8.5-1986 provides guidance on the use of borosilicate-glass raschig rings as a neutron absorber in Section 70.22, "Contents of Applications," of 10 CFR solutions of fissile material. The standard applies to the Part 70, "Domestic Licensing of Special Nuclear Material," use of borosilicate-glass raschig rings for primary and for requires that applications for a specific license to own, secondary

2 39 criticality control in solutions containing 2 3 5 U,

acquire, deliver, receive, possess, use, or transfer special Pu, and 2 3 3 U. The chemical and physical environment, nuclear material contain proposed procedures to avoid properties of the rings and packed vessels, maintenance accidental conditions of criticality. Procedures for this inspection procedures, and criticality operating limits are purpose include incorporating neutron-absorbing material specified in the standard.

such as boron in process equipment. This regulatory guide provides guidance for complying with this portion of the Maximum permissible concentrations of homogeneous Commission's regulations by describing procedures accept- solutions of plutonium or of uranium in vessels of unlimited able to the NRC staff for the prevention of criticality size packed with borosilicate-glass raschig rings are specified accidents by use of borosilicate-glass raschig rings as a in the standard. The concentration of these solutions is neutron absorber in solutions of fissile material. expressed as the mass of plutonium or of uranium per unit volume. The density of hydrogen in any solution Any information collection activities mentioned in this cannot be less than 75 g/liter nor greater than 115 g/liter.

regulatory guide are contained as requirements in 10 CFR Limitations on the relative abundance of the various Part 70, which provides the regulatory basis for this guide. isotopes of plutonium are imposed in the specifications The information collection requirements in 10 CFR Part 70 applicable to plutonium solutions.. The concentrations have been cleared under OMB Clearance No. 3150-0009. specified for uranium enriched in 2 3 sU apply regardless of the 2 3 5 U enrichment content but with a limitation on the

233

B. DISCUSSION

U content. For solutions of uranium containing up to

5.0 wt-% 2 35 U and up to 0.01 wt-% 2 3 3 U (see Table 12 on ANSI/ANS-8.5-1986, "Use of Borosilicate-Glass Raschig page 8 of the standard), the maximum permissible solution Rings as a Neutron Absorber in Solutions of Fissile Mate- concentration is unrestricted. The concentrations specified rial,"' is a revision of ANSI/ANS-8.5-1979 and was pre- for solutions of 2 3 3 U also apply to mixtures of 2 3 3 U and pared by Subcommittee 8, Fissionable Materials Outside other uranium isotopes.

Reactors, of the Standards Committee of the American Nuclear Society. ANSI/ANS-8.5-1986 was approved by the

C. REGULATORY POSITION

American National Standards Committee N16, Nuclear Criticality Safety, in 1985 and by the American National The guidance contained in ANSI/ANS-8.5-1986 for Standards Institute (ANSI) on January 3, 1986. the use of borosilicate-glass raschig rings as a neutron absorber in solutions of fissile material provides a procedure

1Copies may be obtained from the American Nuclear Society, on page 8 of the standard, 41Pu >

2 4 12Pu Note in TblePu thatread should 1 >(3 1 4) PU.

u4

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Regulatory Guides are Issued to describe and make available to the public methods acceptable to the NRC staff of Implementing 1. Power Reactors 6. Products specific parts of the Commission's regulations, to delineate tech- 2. Research and Test Reactors 7. Transportation niques used by the staff In evaluating specific problems or postu- 3. Fuels and Materials Facilities 8. Occupational Health lated accidents or to provide guidance to applicants. Regulatory 4. Environmental and Siting 9. Antitrust and Financial Review Guides are not substitutes for regulations, and compliance with 5. Materials and Plant Protection 10. General them Is not required. Methods and solutions different from those set out In the guides will be acceptable If they provide a basis for the findings requisite to the Issuance or continuance of a permit or Copies of Issued guides may be purchased from the Government license by the Commission. - Printing Office at the current GPO price. Information on current GPO prices may be obtained by contacting the Superintendent of This guide was Issued after consideration of comments received from Documents, U.S. Government Printing Office, Post Office Box the public. Comments and suggestions for Improvements In these 37082, Washington, DC 20013-7082, telephone (202)275-2060 or guides are encouraged at all times, and guides will be revised, as (202)275-2171.

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Issued guides may also be purchased from the National Technical Written comments may be submitted to the Rules and Procedures Information Service on a standing order basis. Details on this Branch, DRR ADM, U.S. Nuclear Regulatory Commission, service may be obtained by writing NTIS, 5285 Rort Royal Road, Washington, D6 20555. Springfield, VA 22161.

generally acceptable to the NRC staff for the prevention of The methods described in this guide were applied in a accidental conditions of criticality. number of specific cases during reviews and selected licensing actions. These methods reflect the latest general Section 8.0 of ANSI/ANS-8.5-1986 lists additional docu- NRC approach to criticality safety in operations involving ments referred to in the standard. The specific applicability use of borosilicate-glass raschig rings as a neutron absorber or acceptability of these listed documents will be covered in solutions of fissile material. Therefore, except in those separately in other regulatory guides, where appropriate. cases in which the applicant proposes an acceptable alter- native method for complying with specified portions of

D. IMPLEMENTATION

the Commission's regulations, the methods described in The purpose of this section is to provide information to this guide will be used in the evaluation of submittals in applicants regarding the NRC staff's plan for using this connection with license applications submitted Uinder regulatory guide. 10 CFR Part 70.

3.1-2

VALUE/IMPACT STATEMENT

A draft value/impact statement was published with the guide has not been prepared. A copy of the draft oposed Revision 2 to Regulatory Guide 3.1 (Task CE value/impact statement is available for inspection and

602-4) when the draft guide was published for public copying for a fee at the Commission's Public Document comment in March 1987. No changes were necessary, Room at 1717 H Street NW., Washington, DC, under so a separate value/impact statement for the final Task CE 602-4.

,.S. G.P.O. 1987-181-682:60212

3.1-3

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