核反应堆研究Nuclear Research Reactors.pptVIP

Nuclear Research Reactors Seminar on Nuclear Science and Technology for Diplomats P. Adelfang(+), N. Ramamoorthy(*) (+)Division of Nuclear Fuel Cycle and Waste Technology (NEFW) Dept. of Nuclear Energy (NE) (*)Division of Physical and Chemical Sciences (NAPC) Dept. of Nuclear Sciences and Applications (NA) IAEA, Vienna, February 6-8, 2007 Nuclear Research Reactors (RR) Outline of Presentation Introduction to RR principles, components RR types and features RR utilization: Techniques and Applications RR issues needs: perceptions and concerns Agency assistance on RRs Some Stories of Success Nuclear Fission, Chain Reaction and Nuclear Reactor Neutron interaction with atoms of heavy nuclei such as uranium-235 leads to a ‘split’ with release of energy 235U + n ? [236U] ? AX + BY + 2 to 3 n + Energy Nuclear Fission Reaction – fissile element + thermal neutron Neutrons released further interact with fissile element ? to chain (fission) reaction with energy release Self sustained controlled chain reaction would lead to a steady state operation ? Device ? Nuclear Reactor Fission: The Chain Reaction Fission: The Chain Reaction Fission: The Chain Reaction Fission: The Chain Reaction Nuclear Research Reactors – Typical Features Typical power levels 30kW to 10MW Intense source of neutrons. Typical steady-state neutron flux: 1011 to 1014 neutrons/cm2.s Vertical and horizontal channels to avail neutrons Various coolants / moderators light water, heavy water, organic liquids Various types of fuel plates, rods, tubes, liquid in homogeneous RR metallic, hydrides, silicides Natural and forced circulation cooling Research Reactors: Some Typical Characteristics Small volume cores 90% have power level less than 10 MW(t) Generally higher enrichment fuel than in power reactors (though some RRs use natural uranium fuel) Natural and forced cooling May have pulsing capability Research Reactor (RR) Types Miniature neutron source reactor (MNSR) of 30kW(t) to about 100MW(