Minor actinide transmutation in the lead-cooled fast reactor

The minor actinides are introduced to a lead-cooled fast reactor (LFR) core in three different approaches to study minor actinide (MA) transmutation characteristics. Power peaking factor calculation results indicate that loading appropriate amount of minor actinide to LFR core does not disturb the neutron flux distribution or power density distribution in LFR core remarkably. This is an advantage of transmutation minor actinides in LFR compared to the minor actinide transmutation characteristics in the PWR reactor. After MA loading to LFR, k(eff) curves deviate from k(eff) curves without minor actinides loading obviously; there is no distinct difference between Ice curves of three minor actinide loading approaches. The LFR core loaded with minor actinides can prolong the fuel cycle to some extent. This is because the created new fissile Pu-238, Am-242. Am-244, Cm-243 and Cm-245 can compensate the reactivity loss due to the consumption of nuclear fuel and sustain the criticality of LFR core. After minor actinide 550-day-exposure in LFR, the concentration of Np-237, Am-241 and Am-243 decreases, while the concentration of (CM)-C-244 and Cm-245 increases. This is because the (241)am and Am-243 capture neutrons and generate Cm-244 and Cm-245. The lead-cooled fast reactor with the thermal power of 750 MW and loading 1 wt % MA nuclides can consume the annual minor actinide yields from about 1.5 typical PWRs. The fraction of plutonium isotopes from LFR reactor spent fuel after MA transmutation is about 85%, the rest being made up of other transuranic isotopes. Plutonium isotopes are important nuclear fuel. Most importantly Pu-238 is a very powerful alpha particle emitter; this makes Pu-238 an ideal material for fabricating radioisotope batteries. In general, transmutation of minor actinides in lead-cooled fast reactors can achieve the goals of elimination of MA nuclide long term radioactive hazards and creation of important Pu-238 material. Therefore, it is feasible to transmute the MA nuclide in lead-cooled fast reactors.