Analysis of power transients observed in spert i reactors, Part 1 - transients in aluminium plate-type reactors initiated at ambient temperature

Abstract

An investigation of SPERT I reactor reactivity feedback mechanisms has been made using the modular code AUS. Feedback terms so obtained have been used in the transient analysis code ZAPP to calculate transient behaviour for step and ramp reactivity additions. A simple model of coolant boiling has been used to analyse transients for which cladding temperatures exceed the saturation temperature of water. The generally good agreement obtained with experimental data supports the case that core only temperature coefficients are much larger than those obtained by heating core and reflector.