HTMR-25 General Design Features
The HTMR-25 is a high temperature helium cooled pebble bed modular generation IV reactor specifically designed to meet the needs of small Islands/remote-regions not served by large electricity-grids.
The technology of the HTMR-25 is based and down sized from the HTMR100. Ideally suited to match the Siemens Indonesia´s SST-140 steam turbine system developed in Indonesia (as pictured on the right-hand side), HTMR-25 can produce 7-9 MWe electricity, 20-28 MWth high quality process-heat/steam for industrial applications, or can be operated in various electricity/heat cogeneration options. It is modular in design and can be transported to any inland location due to small size and limited tritium production and release. It has good load bearing characteristics and is ideally suited as a remote standalone power plant.
The HTMR-25 exhibits the following intrinsic safety characteristics:
• A Once-Through-Then-Out (OTTO) fuel cycle which achieves high burn-up rates fully utilizing fissile material;
• Inherently safe due to huge negative reactivity feedback that naturally eliminate the diverse shutdown requirements that are normally required for water-cooled reactors;
• Use of fully ceramic fuel elements, which cannot melt, even in extreme accidents which may result in the total loss of active core cooling;
• Use of helium as coolant, which is both chemically and radiologically inert and does not influence the neutron balance. It allows for very high coolant temperatures during normal operation;
• Use of fully ceramic (graphite) core internal structures, which enables operation at high temperatures;
• A reactor core with a low power density, providing a thermally robust design with a high heat capacity renders the reactor thermally stable during all operational and control procedures;
• The reactor core can tolerate a loss of forced cooling event. Passive decay heat removal is possible and fuel temperatures stay below admissible values. Therefore, the fission products remain inside the fuel particles even in extreme;
• The reactor can use different fuel compositions including uranium and thorium;
• The reactor will produce less hazardous nuclear waste, which benefits waste management problems.