ML17255A630

Proposed Tech Spec Changes Deleting Restriction on Movement of Spent Fuel Shipping Casks W/Auxiliary Bldg Crane

ML17255A630
Person / Time
Site:	Ginna
Issue date:	01/18/1984
From:	ROCHESTER GAS & ELECTRIC CORP.
To:
Shared Package
ML17255A628	List: ML17255A626 ML17255A629 ML17255A630
References
NUDOCS 8401250293
Download: ML17255A630 (6)

Text

Attachment A Make the following changes in the Technical Specification.

Remove Insert page 3.11-2 page 3.11-2 8401250293 840ii8 PDR *DOCK 05000244 P PDR

~ ~

e. Charcoal adsorbers shall be installed'n the ventilation system exhaust from the spent fuel storage pit area and shall be operable.

3.11.2 Radiation levels in the spent fuel storage area shall be monitored continuously.

t

3. 11.3 The trolley of the auxiliary building crane shall never be stationed or permitted to pass over storage racks containing spent fuel.

3.11.4 The spent fuel pool temperature shall be limited to 150'F.

Basis:

Charcoal adsorbers will reduce significantly the consequences of a refueling accident which considers the clad failure of a single irradiated fuel assembly. Therefore, charcoal adsorbers should be employed whenever irradiated fuel is being handled. This requires that the ventilation system should be operating and drawing air through the adsorbers.

The desired air flow path, when handling irradiated fuel, is from the outside of the building into the operating floor area, toward the spent fuel storage pit, into the area exhaust ducts, through the Amendment No. 21, P4, P5 3 ~ 11 2 Proposed

Appendix B In order to remove the restriction against the handling of a spent fuel shipping cask by the auxiliary building crane, the proposed modification would satisfy the requirements for defining the crane to be single failure proof in accordance with NUREG-0554.

According to NUREG-0612, being able to move a load in a single failure proof mode obviates the need to analyze the cask drop accident.

The 40 ton auxiliary building crane has been reanalyzed for a maximum critical load (MCL) of 30.5 tons characterized as a spent fuel*shipping cask with a redundant yoke.

In=brief, the required modification includes the following:

1. Replacement of the main hoist gear box.

2. Replacement of main hoist drum with a new drum with a 24" pitch diameter. This is to accommodate the larger rope diameter (3/4") and allow area on both ends of the drum for a disc brake system and an overspeed device.

3. Providing a main hoist reeving system with dual ropes and a 10:1 safety factor. This system includes new hoist rope, hook block, head block and equalizer bar.

4. The addition of a Youngstown type power limit switch to back up the existing gear type control limit switch.

This provides protection against two blocking for the main hoist.

5. Addition of an overspeed device to monitor drum speed.

6. The addition of circuitry to prevent bridge and trolley travel while the main hoist is operating. This is for hang-up protection.

7. The addition of structure under the drum to prevent from dropping if the drum shaft fails.

it

8. Providing a braking system applied directly to the drum with an overspeed switch...This prevents loss of load.

at the drum drive fails.

if the drum shaft or any part of the hoist

9. .Addition of overload sensing device to motor circuits to protect hoisting system from overload on load hangup.

10. Addition of a floating rail clamp on the bridge and trolley rails to hold them during a seismic occurrence.

ll. Install one leg a three phase limit switch that in the event of of the three phase power supply de-energizing the brake system will be engaged and all movement of the load and hoist system will stop.

Analysis has shown that the modified crane will be able to hold the MCI during normal operation and during the occurrence of a safe shutdown earthquake.

The following testing will be completed:

1. Material testing in accordance with section 2.4, NUREG-0554.

2. All weld joints whose failure could result in the drop of a critical load will be non destructively examined (Section 2.6).

3. A post-modification test program that meets the general requirements of Section 8 of NUREG-0554.

Since the auxiliary building crane will be single-failure proof, no single failure can result in a fuel cask drop. Therefore a fuel cask drop does not need to be analyzed.

While the proposed modification will satisfy the requirements of NUREG-0612 while moving loads in the single failure proof mode, it may not. be possible to move all loads at all times in this manner. RG6Z will continue to analyze loads that, cannot be moved in a single failure proof mode on a case by case basis to satisfy the requirement of NUREG-0612 by some combination of load drop analysis, load height restrictions and load path.

~ \

Attachment C In accordance with 10CFR 50.91 this change to the Technical Specifications has been evaluated against three criteria to determine if the operation of the facility in accordance with the proposed amendment would:

l. involve a significant increase in the probability or consequences of an accident previously 'evaluated; or

2. create the possibility of a new or different kind of accident from any accident previously evaluated; or

3. involve a significant reduction in a margin of safety.

As outlined below, Rochester Gas & Electric submits that the issues associated with this amendment request are outside the criteria of 10CFR 50.91, and therefore, a no significant hazards finding is warranted. il Attachment B discusses the modification to be made to the auxiliary building crane. The addition of these redundant safety features will prevent the loss of control of a load should the single failure of any crane component occur.

Therefore a no significant hazards finding is warranted for the following reasons:

The probability of a load drop is decreased.

2. The possibility of a different kind of accident is not created.

3. There is an increase in the margin of safety for the movement of any load equal to or less than the MCI .

l 0 0-7