Toshiba Corp. revealed a remotely operated system to remove debris and fuel from the spent fuel pool at Fukushima Daiichi nuclear Unit 3 in Japan.
The Fuel Removal System (FRS) will be installed at the Fukushima site starting now. Testing and training had been performed up to last December, and fuel removal is expected to begin in fiscal year 2017.
During the 2011 accident, a hydrogen explosion inside Unit 3 destroyed the upper part of the reactor building and littered the operation floor and spent fuel pool with debris. The debris and all of the fuel must be removed in order to return the unit to stable condition.
The FRS developed by Toshiba is designed to remove the debris, and to place fuels in a transfer vessel (TV) that can be securely sealed. Once that is completed, the FRS will lift the TV to an above-ground floor of the reactor building for transportation to a temporary storage site.
The FRS consists of a fuel handling machine for removing the debris and fuel, and cranes for bringing in the TVs, closing their lids and hoisting them up to ground-level floor. The fuel handling machine is equipped with two manipulators capable of cutting and grabbing debris and a mast and fuel grapple tool for taking out fuel.
The manipulator tips, auxiliary hoists and fuel grapple tool attached to mast can be replaced with an appropriate cutting or gripping jig via remote control, depending on the state of the debris in the pool. The cranes section consists of the main hoist with the TV lifting rig – which transfers fuel to the TVs – and an auxiliary hoist for removing and securing the TV primary lid.
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