Measurement of Light-Water Reactor Coolant Channel Reduction Arising from Cladding Deformation During a Loss-of-Coolant Accident

The Zircaloy-clad fuel rods of a light-water reactor will deform by swelling during the thermal transient associated with a loss-of-coolant accident (LOCA). This swelling may cause coolant channel blockage of such magnitude that emergency cooling may be impaired. To investigate the effect of tube swelling on coolant flow area, a series of multirod transient burst tests have been conducted under various conditions of internal pressure and heating rates. Results to date have shown a wide range of coolant channel blockage for internal pressures up to 400 psig.