A Python code for computation of absorber rods worth using inverse kinetics

Absorber rods' (ARs) ability to alter the multiplication factor (i.e. reactivity worth) needs to be estimated for operation of the reactor within stipulated limits. In PFBR, this will be done using 'Power-oscillation method'. In this method, reactor power is oscillated between a band of two values with the movement of ARs and reactivity change due to the movement is calculated using the variation of power as a function of time and the reactor kinetics parameters. A code is developed in python programming language to compute the reactivity worth of ARs for a given step using inverse-kinetics equations. Adding the differential reactivity worth of all the steps, integral worth of the rod is also calculated. Due to the presence of noise in power signal, reactivity so obtained has fluctuations, which are smoothened out using moving average technique. Further, fluctuations during a step are averaged to arrive at a single reactivity value for a given step of raising or lowering the AR. The estimated reactivity values from the program are verified against the standard and established codes; and the deviations are found to be within acceptable limit. (author)