Methods for calculating the conduction-controlled rewetting of a cladded rod

Abstract

A theory is presented for the conduction-controlled rewetting of a cladded water-reactor fuel rod. It is assumed that there is no heat loss from the dry part of the rod and that a constant heat transfer coefficient obtains over the wetted part. The analysis, which employs the Wiener-Hopf technique, yields an explicit expression for the logarithm of the sputtering temperature in the form of an integral, the integrand depending upon the speed of the quench front, the dimensions, and physical properties of the composite rod, the fuel-to-clad thermal resistance, and the magnitude of the heat transfer coefficient in the wetted zone. An alternative expression in terms of an infinite product, the terms of which are evaluated by locating the interlacing zeros of a pair of oscillatory functions, is also developed.