The HTTR plant is
composed of a reactor building, a spent fuel storage
building, a machinery building and so on. The reactor
building is 48m by 50m with two floors above ground and
Major components such as the reactor pressure vessel
(RPV), primary cooling system components etc. are all inside
the containment vessel. The construction of the reactor
building began in March 1991 and all major components were
installed by March 1996.
The block type fuel, instead of the pebble-bed, is adopted
in the HTTR considering the advantages of fuel zoning,
control of coolant flow rate in each column, easy insertion
of control rods (CRs), irradiation flexibility in the core.
Core components and reactor internals were installed in the
RPV from May to August 1995.