FFTF Fuel-Handling System

This appendix provides a brief description of the Fast Flux Test Facility (FFTF) fuel handling system and its operation as described by Cabell (1980) and in the Fast Flux Test Facility System Design Description (FFTF, 1983). The description is limited to those system features that are potentially relevant to the refueling of a liquid-salt very high-temperature reactor (LS-VHTR). Because the FFTF was designed as a reactor to test fuel, it has additional capabilities and equipment compared with a sodium-cooled fast reactor designed only to produce electricity. 

The fuel-handling system designs for the EBR-II, FFTF, and CRBRP reflected the requirements imposed by the individual facility missions and reactor system designs. The EBR-II was intended as a developmental prototype for a breeder reactor power station. The FFTF was designed as an irradiation test facility for fuels and materials and the CRBRP was to be a medium-sized demonstration commercial breeder reactor power station. 

The reactor refueling system handles three types of core assemblies 12-ft assemblies, such as driver fuel 40-ft assemblies, such as fuels open test assemblies, which are loaded into the reactor full-length but are cut into two sections before removal and 40-ft assemblies, such as materials open-test assemblies, which are loaded into and removed from the reactor as full-length sections. The typical sequence for driver fuel-handling operation is summarized in Sect. A.2.1, and a brief description of contamination control and inventory control practices is provided in Sect. A.2.2. The FFTF refueling systems are more complex than those of a power reactor because the FFTF is a fuel testing machine that must handle many special test fuel assemblies, many of which require special handling. 

Reactor refueling systems. A series of systems associated with the reactor and reactor vessel are required for refueling. Outside the reactor vessel these include three fuel transfer ports, eight test position spool pieces, two floor valve ad ters and the test transfer port, and the reactor containment building cranes. Inside the reactor vessel are three in-vessel handling machines (IVHMs) and three invessel storage modules. Three IVHMs are required because of the mission of the FFTF that requires closed test loops in the reactor core which interfere with direct access to die entire core with one machine. 

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