The source-multiplication method for absolute reactivity determination

Abstract

A new method for reactivity determination is presented. This method involves two measurements of the reactor response to a neutron source: (a) when subcritical, the source—multiplication, M, is measured and (b) when critical, the linear power rise, R, is measured. The reactivity is then determined from the relation $\text{p/β=}\text{R}\text{M}\text{1}\text{(β/α}\text{+}\text{∑}\text{i}\text{(βdβ)}\text{γ}{}_{\mathrm{i}}$, or from a good approximation to it $\text{ϱ}\text{β}\text{≈}\text{T}{}_{\mathrm{d}}\text{[R/M]}$. This method is compared with the asymptotic—period method; expected accuracy is discussed, and possible measurement procedures are described. The feasibility of combining both methods for the determination of $\text{β}$Λ is discussed.