Abasic study of the structure of the core response in the basic planned SMRs

Book chapter, 2025

In this chapter, the dynamic properties of some planned small modular reactor (SMR) types are investigated with the analytical model, in a similar way as in the previous chapter. This is made in the same format: first the space and frequency dependence of the amplitude and the phase of the components of the Green's function matrix are calculated. Then the system response, i.e. the neutron noise induced by three different perturbations, is investigated, namely the noise induced by an absorber of variable strength, by a vibrating absorber, and by propagating perturbations. The possibilities of diagnostics, i.e. locating the position of the first two perturbations, and determining the transit time of the latter, are assessed. The following SMR types are considered: 1. A small 200 MWth core, which is constructed from shortened fuel elements of a typical pressurised water reactor (PWR) (AP1000); 2. An advanced LWR SMR 3. A fast spectrum molten salt reactor (MSFR) 4. A lead-cooled fast SMR (LFRSMR) 5. A fluoride salt-cooled high-temperature reactor (FHR)