Core Surveillance of Boiling-Water Reactors

Methods suitable for a calculational procedure which determines the three-dimensional power distribution in boilingwater reactors on the basis of in-core detector readings are described. A two-dimensional equation based on diffusion theory is set up, and a method for incorporating detector readings in the solution of this equation is presented.

A three-dimensional calculational method based on nodal theory is developed. Calculations are carried out using this method, and the results are compared with a three-dimensional nodal theory calculation. Finally, parameters affecting the detector readings are examined.