Regulatory Guide 1.13

Spent Fuel Storage Facility Design Basis

ML13350A371
Person / Time
Issue date:	12/31/1975
From:	NRC/OSD
To:
References
RG-1.013, Rev. 1
Download: ML13350A371 (3)

U.S. NUCLEAR REGULATORY COMMISSION Revision 1 December 1975 REGULATORY GUIDE

OFFICE OF STANDARDS DEVELOPMENT

REGULATORY GUIDE 1.13 SPENT FUEL STORAGE FACILITY DESIGN BASIS

A. INTRODUCTION

1. Loss of Water from Storage Pool

• 1.

General Design LrtIerilon oi, rue, atoragt andi Unless protective measures are taken, loss of water Handling Criteria for Nuclear Power Plants," of Appen- from a fuel storage pool could cause ove~htating of the dix A, "General Dsign Critria for Nuclear Power spent luel and resultant damage to ftef-cladding integ- Plants," to 10 CFR .....

...Part

. ..50," "Licensing

.. . o

f. Production

.. rity i and could l resultl in release ee of rapoacti

v. piaterials

.,*'c to to and Utilzation Facilities," requires that fuel storage and the environment, Natural events as

.a q or handling systemls be designed to .assure . .. adequate... ..safety m~~hgh winds, coue "uia s.....

coul damamge th&:itlotlL,*'citihr aamage ue or arcyo under norm al and .postulated . .. ... accident .conditions.

.. It also

.. by bytthe the generation . ._c-rt&igihnilS or highl g nera ion.ofo rrd*)jes. directly or winds requires that these systems be designed with appropriate cause ,,,d,-,,, ,,, to fasn hiuldwinso th, containment, confinement, and filtering systems and be could also c.uns he fa` ,eto. withsta..n tofall noct designed to prevent significant recduction in the L.oolant polcesiwith c f-caloJfwithsta t occur- inventory of the storage facility . . ... under accident , condi- . wen ulo u~cwz¢

w......ithu.tC9 Oceras. of.w.tertig tgrty tions. This guide describes a method acceptable to the wud "he.. c cn.

NRC staff for implementing this criterion.

DISCUSSIONW Drftiling" olheavy w.* ro y loads, such as a 100-ton fuel cask, cl,*

B. DISCUSSION

o w probability, cannot be ruled out in plant

." t ents where such loads are positioned or moved It is important that futel handling and storage faciltfe* i It di to: lin-r over the fuel pool. Possible solutions to this be designed to"potential problem include (1) preventing, preferably by I a. Prevent lotdesign rather than interlocks, heavy loads from being a. P t lo lifted over the pool; (2) using a highly reliable handling would uncover fuel. sys:em designed to prevent dropping of heavy loads as a result of any single failure; or (3) designing the pool to b. Protect the fuel from mechanical damage. withstand dropping of the load without significant S. .... leakage from the pool area in which fuel is stored.

c. Provide the capa y .limiting the potential offsite exposures in the ificant release of radioactivity fro . Even if the measures described above to prevent loss of leak-tight integrity are followed, small leaks may still If spe el rage cilities are not located within occur as a result of structural failure or other unfcresetn the priý a, ontainment or provided with events. For example, equipment failures in systems adequate ective features, radioactive materials could connected to the pool could result in loss of water from be released the environs as a result of either loss of the pool if such loss is not prevented by design. A

water from the storage pool or mechanical damage to permanent fuel-pool-coolant makeup system with a fuel within the pool. moderate capability, and with suitable redundancy or

'*Lines indicate substantive changes from previous issue. backup, could prevent the fuel from being uncovered if I I I

USNRC REGULATORY GUIDES Comments should be sent to the Secretary of the Commission, U.S. Nuclear Regulatory Commission, Washington. D.C. 205. Attentionm Doclsting and Regutlatory Guides are issued to describ. and make Available to the Public Service Section.

malthods accopthble to the NRC %talf of implementing specific pensl OL the Commntision s regulations, to delineate techniques used by the stall in Ovltu The guides ate issued in the following ton broad divisions eting speciitc problems or postulated accidents, or to provide guidance to appli.

cnlto. Regulatory Guides ate not substitute* for regulations. and compliance 1 Power Reactors 6 Product*

,

with them is not required Methods and solutions different from those set out in 2. Research and Test Reactors 7. Transportation the guides will be acceptable it they provide a basie for the findings requisite to J. Fuels end Materials Fi-cilities 8, Occupational Health thdisluAnCe or continuance of a permit or license by the Commistion 4. Eneronmental and Siting 9 Antitrust Review S Materials and Plant Protection to General Demrents and suggestions fo, inmprovements ,n these guides are encouraged t alt times, and guides will be tevised. as AppOoprrate. to accommodate corn Copies of published guides may be obtained by wrraten request indicating the emals and to retlect new inoormation or emper.ence H*owever. cOmments on divisions desitrd to the U S Nuclear Regulatory Commission. Washington. D C.

this guide, of received within about two months Alter ilt issuance. will be par, titcilarly usetul in evaluating the need lot .n early revisiont 2M,. Attention Oirector. Oltice of Staedards Development

such leaks should occur. Early detection of pool leakage suitably controlled during refueling operations. The and fuel damage could be provided by pool-water-level design of the ventilation and filtration system should be monitors and radiation monitors designed to alarm both based on the assumption that the cladding of all of the locally and in a continuously manned location. Timely fuel rods in one fuel bundle might be breached. The 01 operation of building filtration systems can be assured inventory of radioactive materials available for leakage by actuating these systems by a signal from local from the building should be based on the assumptions radiation monitors. given in Regulatory Guide 1.25, "Assumptions Used for Evaluating the Potential Radiological Consequences of a

2. Mechanical Damage to Fuel Fuel Handling Accident in the Fuel Handling and Storage Facility for Boiling and Pressurized Water The release of radioactive material from fuel may Reactors" (Safety Guide 25).

occur during the refueling process, and at other times, as 5. The spent fuel storage facility should have at least a result of fuel-cladding failures or mechanical damage one of the following provisions with respect to the caused by the dropping of fuel elements or the dropping handling of heavy loads, including the refueling cask:

of objects onto fuel elements.

a. Cranes capable of carrying heavy loads should Missiles generated by high winds can also be a be prevented, preferably by design rather than by potential cause of mechanical damage to fuel. Designing interlocks, from moving into the vicinity of the pool; or the fuel storage facility to prevent such missiles from contacting the fuel would eliminate this concern. b. Cranes should be designed to provide sirgle-.

failure-proof handling of heavy loads, so that a single A relatively small amount of mechanical damage to failure will not result in loss of capability of the the fuel might cause significant offiite doses if no dose crane-handling system to perform its safety function; or- reduction features are provided. Use of a controlled leakage building surrounding the fNel storage pool, with c. The fuel pool should be designed to withstand, associated capability to limit releases of radioactive without leakage that could uncover the fuel, the impact material resulting from a refueling accident, appears of the heaviest load to be carried by the crane from the feasible and would do much to eliminate this concern. maximum height to which it can be lifted. If this approach is used, design provisions should be made to

C. REGULATORY POSITION

prevent the crane, when carrying heavy loads, from moving in the vicinity of stored fuel.

I. The spent fuel storage facility (including its structures and equipment except as noted in paragraph 6 6. Drains, permanently connected mechanical or below) should be designed to Category I seismic require- hydraulic systems, and other features that by malopera- ments. tion or failure, could cause loss of coolant that woula uncover fuel should not be installed or included in the

2. The facility should be designed (a) to keep tor- design. Systems for maintaining water quality and nadic winds and missiles generated by these winds from quantity should be designed so that any maloperation or causing significant loss of watertight integrity of the fuel failure of such systems (including failures resulting from storage pool and (b) to keep missiles generated by the Safe Shutdown Earthquake) will not cause fuel to bej I tornadic winds from contacting fuel within the pool.. uncovered. These systems need not otherwise meet Category I seismic requirements.

3. Interlocks should be provided to prevent cranes from passing over stored fuel (or near stored fuel in a 7. Reliable and frequently tested monitoring equip- manner such that if a crane failed, the load could tip ment should be provided to alarm both locally and in a over on stored fuel) when fuel handling is not in continuously manned- location if the water level in the progress. During fuel handling operations, the interlocks fuel storage pool falls below a predetermined level or if may be bypassed and administrative control used to high local-radiation levels are experienced. The high- prevent the crane from carrying loads that are not radiation-level instrumenttation should also actuate the necessary for fuel handling over the stored fuel or other filtration system.

prohibited areas. The facility should be designed to minimize the need for bypassing such interlocks. 8. A seismic Category I makeup system should be provided to add coolant to the poo

l. Appropriate

4. A controlled leakage building should enclose the redundancy or a backup system for filling the pool from fuel pool. The building should be equipped with an a reliable source, such as a lake, river, or onsite seismic appropriate ventilation and filtration system to limit the Category I water-storage facility, should be provided. If potential release of radioactive iodine and other radio- a backup system is used, it need not be a permanently active materials. The building need not be designed to inst.lled system. The capacity of the makeup systems withstand extremely high winds, but leakage should be should be such that water can be supplied at a ratel

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determined by consideration of the leakage rate that

D. IMPLEMENTATION

would be expected as the result of damage to the fuel storage pool from the dropping of loads, from earth- Any of the alternatives in Regulatory Position C.5 of quakes, or from missiles originating in high winds.* Revision I may be applied at the option of applicants for construction perinits and operating licenses for all

• The staff is considering the development of additional guidance plants, regardless of the date of application.

concerning protection against missiles that might be generated by plant failures such as turbine failures. For the present, the protection of the fuel pool against such missiles will be evaluated on a case-by-case basis.

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