United States Nuclear Regulatory Commission - Protecting People and the Environment

Control of Heavy Loads Near Spent Fuel (Generic Letter 78-16)


GL78016 

                               UNITED STATES 
                       NUCLEAR REGULATORY COMMISSION 
                          WASHINGTON, D.C. 20555 
                                     
                               May 16, 1978 

Licensees for all Plants in the Systematic 
  Evaluation Program 

In January, 1978, the NRC published NUREG-0410 entitled "NRC Program for the
Resolution of Generic Issues Related to Nuclear Power Plants."  As part of 
this program, the Task Action Plan for Category A Technical Activity No. 
A-36, "Control of Heavy Loads Near Spent Fuel", was approved. 

As you are aware, overhead handling systems are used to lift heavy objects 
in the vicinity of spent-fuel in both PWRs and BWRs. If a heavy object, 
e.g., a spent fuel shipping cask or a shielding block, were to fall or tip 
onto spent fuel in the storage pool or the reactor core during refueling and
damage the fuel, there could be a release of radioactivity to the 
environment and a potential for radiation over-exposures to inplant 
personnel. If the dropped object is large, and the damaged fuel contained a 
large amount of undecayed fission products, radiation releases to the 
environment could exceed 10 CFR Part 100 guidelines. These concerns are 
currently considered in licensing reviews. We believe there is a need to 
systematically review NRC requirements, facility designs and technical 
specifications regarding the movement of heavy loads, to assess safety 
margins and to improve those margins where warranted. 

The staff efforts currently underway commenced with a detailed evaluation of 
current NRC requirements and licensee procedures for the movement of heavy 
loads near spent fuel. Based on the results of that evaluation assessments 
will be performed of the probabilities and consequences of heavy loads 
damaging spent fuel. A determination will then be made of the need for 
revising the Standard Review Plan, the Standard Format and Content of Safety
Analysis Reports for Nuclear Power Plants and the Standard Technical 
Specifications. 

All licensees except those in the Systematic Evaluation Program are being 
requested to provide information regarding the movement of heavy loads near 
spent fuel at their facilities.  A copy of the information request in 
enclosed for your use.  You need not submit this information for your 
facility at the present, however, it will be required and reviewed during 
the SEP program for your plant. This request had been reviewed by the 
General Accounting Office and approved under Clearance No. B-180225 (R0522). 
This clearance expires February 28, 1981. 
.

                                  - 2 -                       May 16, 1978 

In the interim, while these efforts are ongoing, you should review your 
current procedures for the movement of heavy loads over spent fuel to assure
that the potential for a handling accident which could result in damage for 
spent fuel is kept at a minimum. 

                                        Sincerely, 

                                        Victor Stello, Jr., Director 
                                        Division of Operating Reactors 
                                        Office of Nuclear Reactor Regulation

Enclosure:
Information Request 
.

                                                           Approved by GAO 
                                                           B-180225 (R0522) 
                                                           Expires 2-28-81 
                                 Enclosure 

                           INFORMATION REQUESTED 

1.   Provide a diagram which illustrates the physical relation between the 
     reactor core, the fuel transfer canal, the spent fuel storage pool and 
     the set down, receiving or storage areas for any heavy loads moved on 
     the refueling floor. 

2.   Provide a list of all objects that are required to be moved over the 
     reactor core (during refueling), or the spent fuel storage pool. For 
     each object listed, provide its approximate weight and size, a diagram 
     of the movement path utilized (including carrying height) and the 
     frequency of movement. 

3.   What are the dimensions and weights of the spent fuel casks that are or
     will be used at your facility? 

4.   Identify any heavy load or cask drop analyses performed to date for 
     your facility.  Provide a copy of all such analyses not previously 
     submitted to the NRC staff. 

5.   Identify any heavy loads that are carried over equipment required for 
     the safe shutdown of a plant that is operating at the time the load is 
     moved. Identify what equipment could be affected in the event of a 
     heavy load handling accident (piping, cabling, pumps, etc.) and discuss 
     the feasibility of such an accident affecting this equipment. Describe 
     the basis for your conclusions. 
     
6.   If heavy load are required to be carried over the spent fuel storage 
     pool or fuel transfer canal at your facility, discuss the feasibility 
     of a handling accident which could result in water leakage severe 
     enough to uncover the spent fuel. Describe the basis for your 
     conclusions. 

7.   Describe any design features of your facility which affect the 
     potential for a heavy load handling accident involving spent fuel, 
     e.g., utilization of a single failure-proof crane. 
     
8.   Provide copies of all procedures currently in effect at your facility 
     for the movement of heavy loads over the reactor core during refueling,
     the spent fuel storage pool, or equipment required for the safe 
     shut-down of a plant that is operating at the time the move occurs. 

9.   Discuss the degree to which your facility complies with the eight (8) 
     regulatory positions delineated in Regulatory Guide 1.13 (Revision 1, 
     December, 1975) regarding Spent Fuel Storage Facility Design Basis. 
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