Fuel Researches In The HTTR Project Shohei UETA Nuclear

fuel researches in the httr project shohei ueta nuclear science and energy directorate nuclear applied heat technology division h

Fuel Researches in the HTTR project
Shohei UETA
Nuclear Science and Energy Directorate
Nuclear Applied Heat Technology Division
High Temperature Fuel & Material Group
Japan Atomic Energy Agency (JAEA)
4002 Oarai-machi, Higashiibaraki-gun, Ibaraki-ken, 311-1394, Japan
[email protected]
Abstract
For the establishment of the HTGR fuel technologies in Japan, the fuel
fabrication process with the mass production, the fuel performance
during the HTTR high temperature test operation with 850/950oC of
outlet coolant temperatures and the future plan for post-irradiation
examinations of the HTTR fuel are presented. R&D works for HTTR were
started from 1960’s. The first- and second-loading fuel has been
fabricated with low as-fabricated failure fraction. During the HTTR
normal operation, fractional release of fission gas 88Kr was lower
than 1×10-8 at full power and it was confirmed that high quality fuel
was successfully fabricated by mass-production. Post irradiation
examination(PIE)s of the first loading fuel will be carried out to
confirm fuel behavior under real-HTGR condition.
For upgrading technologies for the Very High Temperature gas-cooled
Reactor (VHTR) fuel, present status and future R&D plan for advanced
HTGR fuels are presented. As the JAEA’s activity, R&Ds for future HTGR
fuel include the following topics; burnup extension for SiC-coated
fuel particle and the development of ZrC-coated fuel particle as
advanced fuel. JAEA has experienced 2 irradiation tests to extend the
burnup with SiC coated fuel particles. Based on these experiences, the
new R&D programs with the new designed SiC-coated fuel particle are
being planned with irradiation tests / PIEs under the possible
international cooperation. And also, the model development is on going
with the benchmarking work in the framework of the IAEA CRP-6. Also,
R&D of ZrC-CFP to develop the advanced VHTR fuel is presented. The new
over-100g-scale coater by bromide process has been constructed at JAEA
Oarai. Coating tests with surrogate particles are being carried out
and the stoichiometric ZrC layer has been obtained. Irradiation test
with ZrC coated particle and fuel performance modeling will be carried
out under I-NERI between US and Japan.