SPARTA: A flux adjustment methodology to interpret complex experiments

Abstract

To accurately determine reactivity from a detector count rate, correcting spatial effects is of prime importance. Simulation methodologies are often used for spatial correction, but they may introduce an additional source of uncertainty if the results of the experiment are also used as the input data for the simulation. This work presents a flux adjustment methodology that can infer experimental reactivity and correct spatial effects without the need for a simulation. It can process the detector signal(s) from a complex experiment, such as a heat balance measurement in the Transient Reactor Test Facility (TREAT) in which control rods are continuously adjusted to maintain a constant power. The methodology presented in this work successfully computed the reactivity and the local spatial variation of the flux from a generated signal. It also proved to be robust against noise and errors on kinetic parameters and provided a credible interpretation of a heat balance experiment in TREAT. An efficient flux adjustment method for complex experiments enables better experiment interpretation that is less reliant on nuclear data evaluations.