Fuel inspection systems

摘要

Damaged fuel rods can leak fission products, worsening the working conditions of containment, and potentially requiring longer outages for cleanup. Varied initiatives in the US and elsewhere have involved utilities, fuel suppliers and others to improve fuel reliability. Utilities can deploy many different combinations of equipment to monitor fuel in situ during planned outages. Fuel sipping systems analyse samples offgas or combinations of water and offgas for the fission products that might indicate a leak. The traditional method involves a vacuum sipping canister installed in guide tube storage cells or in customized support stands. Once a fuel assembly is placed in the canister, a pump creates a vacuum, sucking up fission gases from leaking fuel rods, which then reach detectors. AREVA's system uses two canisters with a cycle time of 10 minutes per canister, or up to eight fuel assemblies per hour. Control consoles can be set up as far as 75 feet from in-pool components. GE-Hitachi also offers a vacuum canister sipping system. Advance Instruments of Taiwan supplies a poolside vacuum sipping system liquid controller and process vacuum sipping controller for use with PWR and BWR fuels. Both can be used with GE equipment, and offer immediate graphic display of measurement results.