Lynchburg, VA--The original concept for the light-water-reactor nuclear-fuel cycle included reprocessing-a procedure never instituted in the United States. Therefore nuclear power plants were not designed to accommodate life-of-plant spent-fuel storage. Until the DOE begins to take delivery of spent fuel at some time in the next century, utilities must find their own solutions to the storage problem.
Conventional storage systems handle the rods in batches and experience problems filling all the spaces in a container. They also do not recover easily from such problems as a broken rod. One method relies upon consolidation, where workers remove fuel rods from the structure and pack them in a tight array. The remaining non-fuel-bearing structure is cut into small pieces to reduce its volume.
The Fuel Master packing system from B & W Fuel Co. deals with one rod at a time. With the storage canister placed between two spent-fuel assemblies, the computerized system alternately transfers rods from each. Two sliding plates with scalloped edges position the rods as they enter the storage canister. Eight sets of sliding plates control the full length of the rods and help to straighten bowed rods.
Fuel design and site services engineer Jeff Attix and his team developed the sliding plates. The first approach was to start with a solid row of rods. In this arrangement, it was not possible to position each rod. "By rotating the pattern 90 degrees, we start with a spaced row," says Attix. "Now, the slotted plates guide each rod into place while holding the previous row in position."
Gravity advances the plate assembly because of its angled mounting. A pneumatic cylinder retracts one of the plates for insertion of the next row.
Additional details...Contact Jeff Attix, B&W Fuel Co., Box 10935, Lynchburg, VA 24506, (804) 832-2738.