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Conference Article: Behaviour of HTGR coated fuel particles at high-temperature tests

Chernikov, A.S.; Lyutikov, R.A.; Kurbakov, S.D.; Repnikov, V.M.; Khromonozhkin, V.V.; Soloviyov, G.I

Abstract

At the temperature range 1200-2600 *C prereactor tests of TRISO fuel particles on the base of UO2, UCxOy and U02+2Al2O3,.SiO2 kernels, and also fuel particle models with ZrC kernels were performed. Isothermal annealings carried out at temperatures of 1400-2600 C, thermogradient ones – at 1200-2200 C (A T = 200-1200 C/cm). It is shown that at heating to 2200 *C integrity of fuel particles is limited by different thermal expansion of PyC and SiC coatings, and also by thermal dissociation of Sic. At higher temperatures the failure is caused by development of high pressures within weakened fuel particles. It is found that uranium migration from alloyed fuel (UCxOy, U02+2A12O03.Si02) in the process of annealing is higher than that from UO2.

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key words: aluminium oxides; annealing; coated fuel particles; fuel element failure; fuel integrity; htgr type reactors; materials testing; performance testing; reactor safety; risk assessment; silicon oxides; temperature range 1000-4000 k; thermal expansion; thermal testing; uranium carbonates; uranium dioxide; validation
Reference:
Technical committee meeting on gas-cooled reactor technology safety and siting Dimitrovgrad (Russian Federation) 21-23 Jun 1989
International Atomic Energy Agency, Vienna (Austria)
IAEA-TC--389.26, pp:562-594