Vanadium detectors offer accuracy and long life

摘要

Rhodium-based detectors have commonly been used in PWRs for in-core neutron flux measurement. In contrast, Canadian Candu reactors have used vanadium-based detectors for over 15, years. Vanadium offers a low depletion rate - about twenty times less than rhodium - and relatively simple cross-section characteristics. What is more, vanadium-based detectors can be more mechanically robust than rhodium detectors. But because vanadium has a longer half-life than rhodium, developers had to consider whether vanadium-based detectors would take longer to respond to a changing power distribution. Westinghouse considered these aspects in developing the Parssel in-core instrument assembly, which is designed to replace the rhodium-based assemblies used in all ABB-CE and B&WPWR designs.