It is essential to understand how crud build-up leads to elevated cladding temperatures and abnormal cladding corrosion for Boiling Water Reactor (BWR) fuel. With a heated rod test loop configuration, the influence of water chemistry on crud build-up and cladding corrosion behavior can be assessed.
A new test loop named the Westinghouse Annular Thermal Crud Hydraulic (WATCH) Loop, has been designed to grow simulated BWR crud under normal BWR operating conditions. WATCH simulates the bottom meter of a BWR core in terms of temperature, flow, steam quality and heat flux. Test results from this loop can be used to benchmark risk assessment tools, which in turn are used to make predictions and minimize or avoid BWR fuel rod failures, consistent with guidelines from the Institute of Nuclear Power Operations (INPO) and the Electric Power Research Institute (EPRI).
In this paper, the Westinghouse Annular Thermal Crud Hydraulic (WATCH) Loop design and development are introduced. The results of a commissioning test and a run producing zinc-rich deposits are also presented.