Status of Rod Consolidation

Several rod consolidation systems have been demonstrated in the United States with simulated boiling water reactor (BWR) and pressurized water reactor (PWR) fuel. The first U.S. consolidation of irradiated fuel was successfully demonstrated with four PWR fuel assemblies at the Oconee Nuclear Station in October-November 1982 (1-3) and with one PWR fuel assembly at Maine Yankee in August 1983(4). Maine Yankee has received approval from the U.S. Nuclear Regulatory Commission (NRC) to consolidate up to 20 fuel assemblies(5). There are two other upcoming rod consolidation demonstrations with irradiated fuel(6). Twelve spent BWR fuel assemblies are to be involved in a demonstration at the Brown Ferry Nuclear Power Plant (equipment was delivered to the site in June 1983) under an interagency agreement between the U.S. Department of Energy (DOE) and the Tennessee Valley Authority (TVA). Five to 10 spent PWR fuel assemblies are currently scheduled to be consolidated in 1985 as part of a comprehensive program by Northeast Utilities Service Co. (NUSCO) with support from the Electric Power Research Institute (EPRI) and Baltimore Gas &Electric Co. The objective of the NUSCO program is to develop benchmarked analytical methods and related data on consolidated fuel characteristics to support licensing of the storage of consolidated fuel in a nuclear spent fuel pool and to demonstrate fuel consolidation with production-scale equipment and processes. Consolidated spent fuel will also be involved in the Virginia Electric and Power Company (VEPCO)/DOE-sponsored dry storage demonstration (6 ,7) at the Idaho National Engineering Laboratory (INEL), Idaho Falls, Idaho.

There has been no experience with extended wet or dry storage of consolidated fuel rods; however, problems are not expected (8). One canister loaded with consolidated fuel rods (2:1 consolidation ratio) has been in wet storage at the Oconee Nuclear Station since the fall of 1982. It could serve as a lead test canister for future licensing activities. Acceptable dry storage conditions for consolidated fuel have yet to be defined(9).