ML20078N379

Proposed Tech Specs Re Oyster Creek Spent Fuel Pool Expansion

ML20078N379
Person / Time
Site:	Oyster Creek
Issue date:	02/08/1995
From:	GENERAL PUBLIC UTILITIES CORP.
To:
Shared Package
ML20078N367	List: ML20078N363 ML20078N379
References
NUDOCS 9502150299
Download: ML20078N379 (2)

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5.3 AUXILIARY EQUIPMENT 1 5.3.1 Fuel Storage l

A. The fuel storage facilities are designed and shall be maintained with a K-effective equivalent to less than or equal to 0.95 including all calculational uncertainties.

B. Loads greater than weight of one fuel assembly shall not be moved over stored irradiated fuel in the spent fuel storage facility.

C. The spent fuel shipping cask shall not be lifted more than six inches above the top plate of the cask drop protection system.

Vertical limit switches shall be operable to assure the six inch vertical limit is met when the cask is above the top plate of the cask drop protection system.

D. The temperature of the water in the spent fuel storage pocl, measured at or near the surface, shall not exceed 125 F.

E. The maximum amount of spent fuel assemblies stored in the spent fuel storage pool shall be 2645. I BASIS The specification of a K-effective less than or equal to 0.95 in fuel storage facilities assures an ample margin from criticality. This limit applies to unirradiated fuel in both the dry storage vault and the spent fuel racks as well as irradiated fuel in the spent fuel racks. Criticality analyses were performed on the poison racks to ensure that a K-effective of 0.95 would not be exceeded.

The analyses took credit for burnable poisons in the fuel and included manufacturing tolerances and uncertainties as described in Section 9.1 of the FSAR. Calculational uncertainties described in 5.3.1.A are explicitly defined in FSAR Section 9.1.2.3.9. Any fuel stored in the fuel storage facilities shall I be bounded by the analyses in these reference documents.

The effects of a dropped fuel bundle onto stored fuel in the spent fuel storage facility has been analyzed. This analysis shows that the fuel bundle drop would not cause doses resulting from ruptured fuel pins that exceed 10 CFR 100 limits (1,2,3) and that dropped waste cans will not damage the pool liner.

The elevation limitation of the spent fuel shipping cask to no more than 6 inches above the top plate of the cask drop protection system prevents loss of the pool integrity resulting from postulated drop accidents. An analysis of the effects of a 100-ton cask drop from 6 inches has been done (4) which showed that the pool structure is capable of sustaining the loads imposed during such a drop. Limit switches on the crane restrict the clevation of the cask to less than or equal to 6 inches when it is above the top plate.

0YSTER CREEK 5.3-1 Amendment No.: 22,76,77,121 9502150299 950208 PDR ADOCK 05000219 P PDR

1 Detailed. structural analysis of the spent fuel pool was performed using loads resulting from the dead weight of the structural elements, the building loads, i hydrostatic loads from the pool water, the weight of fuel and racks stored in the pool, seismic loads, loads due to thermal gradients in the pool floor and the walls, and dynamic load from the cask drop accident. Thermal gradients 1 l

result in two loading conditions; normal operating and the accident conditions l with the loss of spent fuel pool cooling. For the normal condition, the containment air temperature was assumed to vary between 65"F and 110"F while the pool water temperature varied between 85 F and 125'F. The most severe loading from the normal operating thermal gradient results with containment air temperatures at 65 F and the water temperature at 125"F. Air temperature measurements made during all phases of plant operation in the shutdown heat exchanger room, which is directly beneath part of the spent fuel pool floor slab, show that 65*F is the appropriate minimum air temperature. The spent fuel pool water temperature will alarm control room before the water temperature reaches 120 F.

Results of the structural analysis show that the pool structure is structurally adequate for the loadings associated with the normal operation and the condition resulting from the postulated cask drop accident (5) (6).

The floor framing was also found to be capable of withstanding the steady state thermal gradient conditions with the pool water temperature at 150*F without exceeding ACI Code requirements. The walls are also capable of operation at a steady state condition with the pool water temperature at 140 F (5).

Since the cooled 'uel pool water returns at the bottom of the pool and the heated water is removed from the surface, the average of the surface temperature and the fuel pool cooling return water is an appropriate estimate of the average bulk temperature; alternately the pool surface temperature could be conservatively used.

References

1. Amendment No. 78 to FDSAR (Section 7)

2. Supplement No. I to Amendment No. 78 to the FDSAR (Question 12)

3. Supplement No. I to Amendment 78 of the FDSAR (Question 40)

4. Supplement No. I to Amendment 68 of the FDSAR

5. Revision No. I to Addendum 2 to Supplement No. I to Amendment No.

78 of FDSAR (Questions 5 and 10)

6. FDSAR Amendment No. 79

7. Deleted l OYSTER CREEK 5.3-2 Amendment No. 121

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