Chemistry and release of radioisotopes in LBE

In MYRRHA, LBE is used as both spallation target material and primary coolant. Because of the interactions with the proton beam and neutrons produced in the reactor core with the main constituents of the coolant Pb, and Bi, many radioactive elements are created. These include spallation products with masses close to that of the coolant atoms (such as Hg) and activation products of which Po is the most important. In addition, potentially volatile fission products such as I, Cs and Te may be released in the coolant after a breach in the fuel cladding. Reliable information on the release of these elements from the coolant is needed as input for safety calculations. To certain extent, the chemical properties of some elements like Hg and some fission products are known or can be estimated from existing data. Therefore, our work is focussed on cases where literature data are lacking.