ISSN:
1662-0356
Source:
Scientific.Net: Materials Science & Technology / Trans Tech Publications Archiv 1984-2008
Topics:
Natural Sciences in General
,
Technology
Notes:
The toxicity of the UO2 spent fuel is dominated by plutonium and minor actinides (MA): Np, Am and Cm, afterdecay of the short live fission products. Zirconia ceramics containing Pu and MA in the form of an Inert Matrix Fuel (IMF)could be used to burn these actinides in Light Water Reactors. Optimisation of the fuel designs dictated by properties such asthermal, mechanical, chemical and physical must be performed with attention for their behaviour under irradiation. Zirconiamust be stabilised by yttria to form a solid solution such as AnzYyPuxZr1-yO2-y where minor actinide oxides are also soluble.Burnable poison may be added if necessary such as Gd, Ho, Er, Eu or Np, Am them-self. These cubic solid solutions arestable under heavy ion irradiation. The retention of fission products in zirconia, under similar thermodynamic conditions, is apriori stronger, compared to UO2, the lattice parameter being larger for UO2 than for (Y,Zr)O2-x. (Er,Y,Pu,Zr)O2-x in which Pucontains 5% Am was successfully irradiated in the Proteus reactor at PSI, in the HFR facility, Petten as well as in the HaldenReactor. These irradiations make the Swiss scientists confident to irradiate such IMF in a commercial reactor that wouldallow later a commercial deployment of such a fuel for Pu and MA utilisation in a last cycle. The fuel forms namely pellet ofsolid solution, cercer or cermet fuel are discussed considering the once through strategy. For this strategy, low solubility ofthe inert matrix is required for geological disposal. As spent fuels these IMF’s are demanding materials from the solubilitypoint of view, this parameter was studied in detail for a range of solutions corresponding to groundwater under near fieldconditions. Under these conditions the IMF solubility is 106 times smaller than glass, which makes the zirconia material veryattractive for deep geological disposal. The desired objective would be to use IMF to produce energy in reactors, opting foran economical and ecological solution
Type of Medium:
Electronic Resource
URL:
http://www.tib-hannover.de/fulltexts/2011/0528/01/42/transtech_doi~10.4028%252Fwww.scientific.net%252FAST.45.1907.pdf
Permalink