Authors & Affiliations

Kinev E.A.1,2, Tsygvintsev V.A. 1
1 Institute of Nuclear Materials, Zarechny, Russia
2 National Research Nuclear University "MIFI", Moscow, Russia

Kinev E.A. – Leading Researcher, Cand. Sci. (Tech.), Institute of Nuclear Materials. Contacts: PO Box 29, Zarechny, Sverdlovsk region, Russia, 624250. Tel.: +7(34377)3-51-18; e-mail: This email address is being protected from spambots. You need JavaScript enabled to view it..
Tsygvintsev V.A. – Senior Researcher, Institute of Nuclear Materials.

Abstract

For decrease of fuel multiplier in electrical power cost and competitiveness with thermal nuclear reactors the essential increase of new generation fast reactors fuel burnup is required. The analysis of materials science investigations of structure, porosity, lattice parameter, pressure of gaseous fission products for uranium dioxide, mixed uranium-plutonium oxide and dense uranium pellet fuel after irradiation in fast neutron spectra have been made. The comparison between investigated characteristics for short-term (less than 1% FIMA) and maximum (~14% FIMA) burnup have been executed. It is shown that to exception undesirable thermomechanical interaction of dense fuel with the cladding at high burning out the increased technological porosity or central hole in fuel pellets may be demanded. The same type interaction of uranium dioxide fuel at 14% FIMA is essentially weakened under formation of highly-porous unstable periphery Rim-area and pellet creep. The internal pressure of gaseous fission products in fuel elements at working temperatures and maximum investigated burnup exceeds 6 MPa (circumferential stress of the cladding is nearby 55 MPa). It may require increase of free volume of fuel element compensation space which provides 16-20% FIMA burnup.

Keywords
uranium dioxide, uranium-plutonium oxide fuel, dense uranium fuel, porosity, crystal lattice parameter, gas release, mechanical interaction fuel-cover, circumferential stress of a cladding

Article Text (PDF, in Russian)

References

UDC 621.039.531

Problems of Atomic Science and Technology. Series: Nuclear and Reactor Constants", 2018, issue 3, 3:13