MICRODOSIMETRY STUDY OF RADIOBIOLOGICAL FACILITIES AT THE RSV-TAPIRO REACTOR

The standard irradiation facility of the RSV-Tapiro fast reactor at EN EA Casaccia consists of a vertical channel of 10 cm diameter through w hich biological samples can be shipped down near to the reactor core. A new irradiation facility was designed by extracting laterally the th ermal column to enable irradiation of larger matrices. Microdosimetric measurements were performed using a Rossi counter (d = 2 mum) to prov ide a quantitative assessment of radiation quality for both facilities . Their characteristics were compared in terms of distributions in lin eal energy, and the related averaged quantities, for the total radiati on and the neutron component. The lineal energy spectra were also comp uted using calculated neutron fluence spectra to compare the influence of different energy components, and extend the microdosimetric data t o simulated diameters of 1-0.3 mum to be discussed with regard to thei r relevance for the interpretation of biological results.