Nuclear power small reactor systems

Nuclear power plant systems may be classified as "Frontline" and "Support. . iccurding to their. service in an accident. Frontline systems are the engineered safety systems that deal directly with an accident. Support systems support the frontline systems. Accident initiators are broadly grouped as loss of cooling accidents (LOCAs) or transients. In a LOCA, water cooling the reactor is lost by failure of the cooling envelope. These are typically classified as small-small (SSLOCA), smalt (SLOCA), medium (MLOCA) and large (LLOCA). 

Nuclear and magneto-hydrodynamic electric power generation systems have been produced on a scale which could lead to industrial production, but to-date technical problems, mainly connected with corrosion of the containing materials, has hampered full-scale development. In the case of nuclear power, the proposed fast reactor, which uses fast neutron fission in a small nuclear fuel element, by comparison with fuel rods in thermal neutron reactors, requires a more rapid heat removal than is possible by water cooling, and a liquid sodium-potassium alloy has been used in the development of a near-industrial generator. The fuel container is a vanadium sheath with a niobium outer cladding, since this has a low fast neutron capture cross-section and a low rate of corrosion by the liquid metal coolant. The liquid metal coolant is transported from the fuel to the turbine generating the electric power in stainless steel... 

Even if terrorists succeeded in detonating an explosive at a reactor site, the health consequences would be limited. The reactor accident at the Three Mile Island, Pennsylvania nuclear power plant caused a small release of radiation, insufficient to cause any radiation injuries. Bypassing several safety systems caused the Chernobyl reactor incident, involving two explosions, fires and reactor core meltdown. This accident caused the following early phase health effects (1) ... 

Some AGM participants pointed out that small reactor concepts which are currently developed are based on downsizing today s large reactor technology. They consider that die infrastructure necessary to support conventional nuclear power development is very expensive, and beyond the resources of most developing countries. A new innovative approach to system design is to be used to reduce the need for such an infrastructure. The efforts should be focused on the development of the reactor systems with joint consideration of the overall fuel cycle, waste issues proliferation, simplified operation, simplified and minimised system maintenance. Several organizations presented their preliminary studies on innovative small reactor concepts. 

Transportation and installation of barge- or ship-mounted small nuclear power systems is clearly feasible. Designs for barge-mounted conventional nuclear systems was near reality in the early 1970s, and even today, ship-mounted small reactor concepts are being proposed. 

In a nuclear power station, there are several ion-exchange systems for water clean-up. In a typical BWR there are purification circuits after the steam condenser, in a small stream from the reactor vessel and for the water in the fuel storage pool. In a pressurized water reactor (PWR), part of the coolant in the primary circuit is withdrawn, cooled, and pumped through an ion-exchange filter. As indicated by the word filter, these ion exchangers are also used to remove particles from the liquids. They often consist of mixed cation and anion exchangers that are very finely ground bead sizes of 400 mesh are common. 

As with all nuclear power systems, small reactors would have a substantial advantage relative to conventional power sources with respect to transportation and storage needs for fuel. 

There is an increasing interest among Member States in the potential for deployment of smaller nuclear power plant units as energy sources for power production, heat generation, co-generation of heat and electricity, desalination, etc., and the IAEA has made an updated survey of the design and development status of small and medium power reactors (SMR) systems. 

The objectives of this report are to provide a balanced review of the current discussion on SMR potential and common features to both high level decision makers and technical managers. The report presents a review of the economic market and financial aspects of such systems. It also provides highlights of the incentives for the developments, as well as the main objectives and requirements currently under discussion in many Member States that are interested in nuclear power based on the deployment of small and medium power reactors. 

The small power reactor plant ABV is designed as a unified steam supply system for autonomous nuclear power sources intended for electricity, steam and fresh water production in little-developed regions, as well as for heating mdustnal plants and settlements... 

As discussed in more detail in Section 6.5, a few OECD countries which do not as yet have nuclear power programmes have electrical systems which are too small, now and up to year 2000, to accommodate reactors of 700 MWe or... 

VI-2] MITENKOV, F.M., PANOV, YU.K., POLUNICHEV, V.I., BELIAEV, V.M., The KLT-40S reactor system for the floating unit of the thermal power plant. The Strategy of Nuclear Power Development in Russia and Countries of the Asian-Pacific Basin (Paper presented at the scientific and technical conf, Moscow, 1998). [VI-3] MITENKOV, F.M., POLUNICHEV, V.I., Small nuclear heat and power co-generation stations and water desalination complexes on the basis of marine reactor plants, Nuclear Engineering and Design, Vol.173, Nos. 1-3, pp. 183-191 (1997). 

XXII-2] SIENICKI, J.J., MOISSEYTSEV, A.V., SSTAR lead-cooled, small modular fast reactor for deployment at remote sites - system thermal hydraulic development, ICAPP 2005, Paper 5426 (Int. Conf on Advances in Nuclear Power Plants Seoul, May 15-19, 2005). 

The MARS nuclear power plant (NPP) is being developed as part of an innovative nuclear energy system considered by experts of the Russian Research Centre Kurchatov Institute for the future large-scale deployment of small reactors. The system includes the operating small nuclear power plants and the complete infrastructure chain supporting their deployment, operation, transportation, repair, maintenance, refuelling and decommissioning. 

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