ML20206H618

Proposed Rev 2 to Reg Guide 3.1, Use of Borosilicate-Glass Raschig Rings as Neutron Absorber in Solutions of Fissile Matl

ML20206H618
Person / Time
Issue date:	03/31/1987
From:	NRC OFFICE OF NUCLEAR REGULATORY RESEARCH (RES)
To:
Shared Package
ML20206H621	List: ML20206H618 ML20206H652
References
TASK-CE-602-4, TASK-RE REGGD-03.001, REGGD-3.001, NUDOCS 8704150401
Download: ML20206H618 (3)

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[ S U.S. NUCLEAR REGULATORY C0>9tISSION March 1987 3 j OFFICE OF NUCLEAR REGULATORY RESEARCH Division 3 t

) ' ..... *#c ORAFT REGULATORY GUIDE AND VALUE/ IMPACT STATEMENT Task CE 602-4

Contact:

K. G. Steyer (301)443-7739 PROPOSED REVISION 2 TO REGULATORY GUIDE 3.1 USE OF BOR0 SILICATE-GLASS RASCHIG RINGS AS A NEUTRON ABSORBER IN SOLUTIONS OF FISSILE MATERIAL A. INTRODUCTION Section 70.22, " Contents of Applications," of 10 CFR Part 70, " Domestic Licensing of Special Nuclear Material," requires that applications for a specific license to own, acquire, deliver, receive, possess, use, or transfer special nuclear material contain proposed procedures to avoid accidental con-ditions of criticality. Procedures for this purpose include incorporating neutron-absorbing material such as boron in process equipment. This regulatory guide provides guidance for complying with this portion of the Commission's regulations by describing procedures acceptable to the NRC staff for the pre-vention of criticality accidents by use of borosilicate glass raschig rings as a neutron absorber in solutions of fissile material.

Any information collection activities mentioned in this draft regulatory guide are contained as requirements in 10 CFR Part 70, which provides the regulatory basis for this guide. The information collection requirements in 10 CFR Part 70 have been cleared under OMB Clearance No. 3150-0009.

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-Q B. DISCUSSION n a.

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S ANSI /ANS-8.5-1986, "Use of Borosilicate-Glass Raschig Rings as a Neutron "j Absorber in Solutions of Fissile Material,"1 is a revision of ANSI /ANS-8.5-1979 itom Otu nz-

-02 0 Copies may be obtained from the American Nuclear Society, 555 North Kensington

$2 Avenue, La Grange Park, Illinois 60525.

f% Q n (D o.O This regulatory guide and the associated value/ impact statement are being issued in draft form to involve the public in the early stages of the development of a regulatory position in this area. They have not received complete staff review and do not represent an official NRC staff position.

Public comments are being solicited on both drafts, the guide (including any implementation schedule) and the value/ impact statement. Comments on the value/ impact statement should be accompanied by supporting data. Written comments may be sub-mitted to the Rules and Procedures Branch, ORR, ADM, U.S. Nuclear Regulatory Commission, Washington, DC 20555. Comments may also be delivered to Room 4000. Maryland National SaniL Building. 7735 Old Georgetown Road, Bethesda, Maryland from 8:15 a.m. to 4:00 p.m. Copies of comments received may be examined at the NRC PubllC Document Room,1717 H 5treet NW. ,

washington, DC. Comments will be most helpful if received by June 5,1987.

Requests for single copies of draft guides (which may be reproduced) or for placement on an automatic distribution list for single copies of future draft guides in specific divisions should be made in writing to the U.S. Nuclear Regulatory Commission, Washington DC 20555. Attention: Director, Division of Technical Information and Document Control.

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and was prepared by Subcommittee 8, Fissionable Materials Outside Reactors, of the Standards Committee of the American Nuclear Society. ANSI /ANS-8.5-1986 was approved by the American National Standards Committee N16, Nuclear Criticality Safety, in 1985 and by the American National Standards Institute (ANSI) on January 3,1986.

ANSI /ANS-8.5-1986 provides guidance on the use of borosilicate glass j raschig rings as a neutron absorber in solutions of fissile material. The standard applies to the use of borosilicate glass raschig rings for primary and for secondary criticality control in solutions containing 23sU, 239pu, and 233U.

The chemical and physical environment, properties of the rings and packed vessels, maintenance inspection procedures, and criticality operating limits are specified in the standard.

t Maximum permissible concentrations of homogeneous solutions of plutonium or of uranium in vessels of unlimited size packed with borosilicate glass raschig rings are specified in the standard. The concentration of these solu-tions is expressed as the mass of plutonium or of uranium per unit volume. The density of hydrogen in any solution cannot be less than 75 g/ liter nor greater than 115 g/ liter. Limitations on the relative abundance of the various iso-topes of plutonium are imposed in the specifications applicable to plutonium solutions.* The concentrations specified for uranium enriched in 23sU apply regardless of the 23su enrichment content but with a limitation on the 233U content. For solutions of uranium containing up to 5.0 wt-% 23su and up to 0.01 wt-% 233U (see Table 1 on page 8 of the standard), the maximum permissible solution concentration is unrestricted. The concentrations specified for solutions of 2330 also apply to mixtures of 233U and other uranium isotopes.

C. REGULATORY POSITION The guidance containea in ANSI /ANS-8.5-1986 for the use of borosilicate-glass raschig rings as a neutron absorber in solutions of fissile material provides a procedure generally acceptable to the NRC staff for the prevention of accidental conditions of criticality.

• Note that in Table 1 (3, 4) on page 8 of the standard, 241Pu > 241Pu should read 240Pu > 241Pu.

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