Regulatory Guide 3.49

(Task FP-0806-6), Design of Independent Spent Fuel Storage Installation (Water Basin Type)

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Issue date:	12/31/1981
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U.S. NUCLEAR REGULATORY COMMISSION December 1981

)REGULATORY GUIDE

"OFFICEOF NUCLEAR REGULATORY RESEARCH

REGULATORY GUIDE 3.49 (Task FP 806-6)

DESIGN OF AN INDEPENDENT SPENT FUEL STORAGE INSTALLATION

(WATER-BASIN TYPE)

A. INTRODUCTION

2. Section 7 of ANSI/ANS 57.7-1981 lists the codes and standards that are referenced in this standard. Endorsement Subpart F, "General Design Criteria," of 10 CFR Part 72, of ANSI/ANS 57.7-1981 by this regulatory guide does not

"Licensing Requirements for the Storage of Spent Fuel in constitute an endorsement of the referenced codes and an Independent Spent Fuel Storage Installation," presents standards.

the general design criteria that are applicable to an inde pendent spent fuel storage installation (ISFSI). This regu 3. ANSI/ANS 57.7-1981 includes a number of appendices.

latory guide provides guidance acceptable to the NRC staff Endorsement of this standard by this regulatory guide does for use in the design of an ISFSI of the water-basin type not constitute an endorsement of these appendices.

that will comply with these general design criteria.

4. The design should conform to all "shall" statements

B. DISCUSSION

of the standard, not only to those shown in "boxes."

Group 57.7 of Subcommittee ANS-55 (Fuel and Waste 5. Section 1.3(d) states that the normal water level of the Management) of the American Nuclear Society has developed storage pool can be at or near final design grade level. This a standard, ANSI/ANS 57.7-1981, "Design Criteria for an is acceptable, however, the water level for in-storage radia Independent Spent Fuel Storage Installation (Water-Pool tion shielding should be at or below grade. This means that Type)." 1 It was approved for publication by the American the normal water level of the storage pool may exceed the National Standards Institute on February 19, 1981. The water level of the radiation shielding.

standard defines the design criteria for a water-basin-type independent spent fuel storage installation. 6. In Section 2.1.4.1, the statement that".., the designer may exclude such events as criticality, total loss of pool

C. REGULATORY POSITION

water, and dropped cask as Design Event IV possible events" is misleading. If these events are not considered, the ANSI/ANS 57.7-1981 is acceptable to the NRC staff for justification for not considering them should be presented use in the design of an ISFSI that uses water pools as the in the design documentation, such as the Safety Analysis mode of storage subject to the following' Report

1. ANSI/ANS 57.7-1981 makes reference for design input 7. Section 5.3 uses the term "forced cooling." The NRC

of siting parameters to a companion standard, ANSI/ANS 2.19 staff interprets this term to mean circulation of the pool water through heat exchangers, not controlled flow through

1981, "Guidelines for Establishing Site-Related Parameters individual storage rack channels. The term implies that the for Site Selection and Design of an Independent Spent Fuel storage pool water will be circulated through a heat exchange Storage Installation (Water-Pool Type),"' which has not device to provide continuous cooling. Experience indicates been endorsed by the NRC. Until ANSI/ANS 2.19-1981 is endorsed by the NRC, the users of ANSI/ANS 57.7-1981 that continuous forced cooling may not be necessary.

should seek guidance from the NRC staff on siting param

8. In addition to meeting the requirements of Sections 5.3 eters that are used as design input.

and 6.3.2.7, provisions should be made for the use of

1 portable cleanup devices for areas within the storage pool in Copies may be obtained from the American Nuclear Society,

555 North Kensington Avenue, La Grange Park, Illinois 60525. which contaminated particulate material could be deposited.

USNRC REGULATORY GUIDES Comments should be sent to the Secretary of the Commission, U.S. Nuclear Regulatory Commission, Washington, D.C. 20555, Attention: Docketing and Service Branch.

Regulatory Guides are issued to describe and make available to the public methods acceptable to the NRC staff of implementing The guides are issued in the following ten broad divisions:

specific parts of the Commission's regulations, to delineate tech niques used by the staff in evaluating specific problems or postu 1. Power Reactors 6. Products lated accidents, or to provide guidance to applicants. Regulatory 2. Research and Test Reactors 7. Transportation Guides are no substitutes for regulations, and compliance with

8. Occupational Health

3. Fuels and Materials Facilities them is not required. Methods and solutions different from those set 9. Antitrust and Financial Review guides will be acceptable if they provide a basis for the 4. Environmental and Siting out in the 1

0. General

. findings requisite to the issuance or continuance of a permit or 5. Materials and Plant Protection license by the Commission.

Copies of issued guides may be purchased at the current Government This guide was issued after consideration of comments received from Printing Office price. A subscription service for future guides in spe cific divisions is available through the Government Printing Office.

the public. Comments and suggestions for improvements in these guides are encouraged at all times, and guides will be revised, as Information on the subscription service and current GPO prices may be obtained by writing the U.S. Nuclear Regulatory Commission, appropriate, to accommodate comments and to reflect new informa Washington, D.C. 20555, Attention: Publications Sales Manager.

tion or experience.

These areas may include the pool corners or other areas should be used: ". . . with commercial and Federal Govern where flow is reduced. Over long periods of time, these ment codes and standards."

areas could become contamination sources that could increase the water radioactivity when disturbed. 16. In Section 6.11.2, the term "industrial sabotage"

should be interpreted to mean "radiological sabotage."

9. Section 5.9.3 requires that the process system, effluent, and area radiation levels be monitored for direct 17. In Section 6.11.3.1, the equipment used to handle radiation and gaseous and airborne particulate activity for casks containing spent fuel and spent fuel assemblies should Design Events I and II. Such monitoring should also be be considered vital equipment. Spent fuel in pools whose done for Design Event III, which is defined as an event that configuration is susceptible to successful sabotage should can reasonably be expected to occur once during the also be considered vital and should be protected as vital lifetime of the installation. This type of event could cause equipment in accordance with the provisions of 10 CFR

significant increases in direct radiation or airborne particulate Part 73.50.

activity that must be immediately detected and monitored throughout the course of the event. 18. Section 6.11.3.2 requires that gates normally used for admittance of vehicles to the protected area be provided

10. If supply air for the unit subsystem is drawn from the with a remote control capability. The NRC does not require main building ventilation subsystem as permitted by but only recommends this capability for vehicle gates.

paragraph 6.6.2.2.3, methods to prevent the backflow of Also in this section, the term "remote control capability"

potential contamination (e.g., dampers or high-efficiency should be interpreted to mean "remote locking/unlocking particulate air filtration) from the unit subsystem to the capability" or "remote opening/closing capability."

main building subsystem during partial loss-of-power occurrences or other abnormal conditions should be provided. 19. The central alarm station required by paragraph 6.11.3.4 should be "hardened" as described in NUREG/CR-0543,

11. In addition to meeting the requirements of Section "Central Alarm Station and Secondary Alarm Station

2

6.6.4.2, the design should use containerized or modulized Planning Document."

filters wherever possible. The use of this type of filter reduces individual exposure to radiation during maintenance 20. In addition to the references to Title 10, "Energy,"

operations. in Section 7, the applicant should refer to 10 CFR Part 72,

"Licensing Requirements for the Storage of Spent Fuel in

12. In addition to meeting the requirements of Sec an Independent Spent Fuel Storage Installation."

tion 6.7.2, the design should include provisions for an equipment decontamination area and a personnel decon

D. IMPLEMENTATION

tamination area. Both areas will be needed to support operations and help minimize radiation exposures of The purpose of this section is to provide information to personnel. applicants and licensees regarding the NRC staff's plan for using this regulatory guide.

13. In addition to the instrumentation required by paragraph 6.9.2.3.5, instrumentation should be provided to Except in those cases in which the applicant or licensee detect and annunciate high airborne radioactivity levels. proposes an acceptable alternative method for complying This requirement should be met by the installation of with specified portions of the Commission's regulations, the continuous air monitors in those areas of potentially high staff will use the methods or practices described herein in airborne radioactivity. the evaluation of the design of a water-basin-type indepen dent spent fuel storage installation after January 1982.

14. In addition to the requirements of Section 6.11, the physical security system should include alarm systems 2 or other means to detect intrusions. NUREG/CR-0543 is available for inspection or copying for a fee at the U.S. NRC Public Document Room, 1717 H Streetl NW.,

Washington, D.C. Copies may be purchased through the NRC/GPO,

15. In the first sentence of Section 6.11.1.1, instead of Sales Program, U.S. Nuclear Regulatory Commission, Washington,

".... D.C. 20555, or from the National Technical Information Service, with commercial codes and standards," the following Springfield, VA 22161.

3.49-2

VALUE/IMPACT STATEMENT

1. ACTION

2. TECHNICAL APPROACH

1.1 Description The document endorses the February 1981 version of ANSI/ANS 57.7-1981, which presents the design criteria Group 57.7 of Subcommittee ANS-55 (Fuel and Waste for an ISFSI.

Management) of the American Nuclear Society has developed a standard, ANSI/ANS 57.7-1981, "Design Criteria for an Independent Spent Fuel Storage Installation (Water-Pool

3. PROCEDURAL APPROACH

Type)."

Procedurally, the choices for making this information

1.2 Need for Action available are through the following publications:

The construction and operation of a water-basin-type "* Regulation independent spent fuel storage installation (ISFSI) are "* NUREG-series report being considered by various organizations within the nuclear "* Branch position paper industry. A need for guidance concerning the design of these "° Regulatory guide facilities has been identified. Standard ANSI/ANS 57.7-1981 provides design criteria for an ISFSI of the water-basin type. As the matter is not a requirement or the only way of A document that addresses the acceptability of ANSI/ANS meeting a requirement, it is not an appropriate subject for

57.7-1981 to the NRC staff is desirable at this time. rulemaking action. As regulatory positions are stated, it would be inappropriate to publish this material as a NUREG

1.3 Value/Impact of Action series report. This material could be published as a branch position paper, but it was considered more appropriate to

1.3.1 NRC use the more formal procedural approach represented by a regulatory guide.

Guidance is needed by the NRC staff to evaluate the design of pool-type ISFSIs. The document provides excep tions and supplements to ANSI/ANS57.7-1981 that 4. STATUTORY CONSIDERATIONS

provide this guidance.

4.1 NRC Authority

1.3.2 Other Government Agencies Section 72.15, "Contents of Application; Technical The guidance may be applicable to TVA. Information," of 10 CFR Part 72 requires that applications to store spent fuel in an ISFSI contain a Safety Analysis

1.3.3 Industry Report. The Safety Analysis Report contains information concerning the design of the ISFSI. The guide addresses the The guidance may be applicable to industry during the NRC views on the standard.

design of new facilities. The document also provides the NRC exceptions to the ANSI standard.

4.2 Need for NEPA Assessment

1.3.4 Workers The guide is not a major action, and hence does not The principle as applied to maintaining occupational require an environmental impact statement.

exposure to radiation as low as reasonably achievable is addressed.

5. RELATIONSHIP TO OTHER EXISTING OR PRO

1.3.5 Public POSED REGULATIONS OR POLICIES

The protection of the health and safety of the public None.

and the environment is addressed in the document.

1.4 Decision on the Action 6. SUMMARY AND CONCLUSIONS

The document follows established NRC practice of A regulatory guide endorsing ANSI/ANS 57.7-1981 should endorsing national standards. be published.

3.49-3

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