Nuclear plants capabilities

High availability and reliability— Availability is defined as the percentage of time that a system is capable of producing electricity. Availability of 95-99% is typical for modern geothermal plants compared to maximum 80-85% for coal and nuclear plants. ... 

Application of liquid metals to nuclear plants requires extremely high standards. Equipment must be dependable, maintenance-free, and capable of operation at elevated temperatures. Purity of the coolant must be maintained at high levels piping systems and their components must be almost perfectly sealed. Special equipment was developed to move, measure, and maintain the liquid metals used in this service. In general, this equipment must be completely sealed and incapable of contaminating the fluid it handles. 

The KLT-40C NSSS created with reliance upon the proven technology of nuclear propulsion plants of icebreak type, involving also utilization of idiip-building technologies, is a reliable and safe plant capable of minimizing environmental impacts compared to altemafive fos -fired power plants. NPP with such NSSS can be situated in close vicinity of settlements. 

This report will concentrate on ASME XI procedures as these have been most widely applied in the RPIS inspections. Since the introduction of the ASME XI code for nuclear plant in 1970 there has been a series of revisions which have considerably changed the inspection requirements. In theory the code in application at the time of construction is the code which applies throughout the life of the vessel, but in fact in our experience the owners of nuclear plants often update their inspection requirements beyond those originally required. As an inspecting organisation it is therefore important to improve ones capabilities to meet existing contracts and to anticipate new work. This is done by improvement made within RPIS and by association with the RNL NDT Development Groups. 

From a very fundamental point of view, a coolant must be capable of removing the heat from a reactor with a reasonable expenditure of pumping power. The heat removal rate per unit frontal area of coolant is simply the product of the coolant density, velocity, specific heat, and the temperature rise across the core, i.e., pvCp AT. Typical values of these parameters for water, helium, and sodium coolants are illustrated in Table 11. The coolant-gas velocities are generally consistent with a pumping power of 5 to 10% of the electrical output of the nuclear plant. 

Heat sink could be defined as the complex of sources of service water necessary to operate, shutdown and cool-down a nuclear plant safely. The issue is to deal widi the reliability of the sources themselves such as rivers, lakes, ponds and the reliability of systems and components intended to transfer heat ifom safety related systems to the cold sources. The ultimate heat sink must be shown to be capable of dissipating the heat following normal or abnormal situations, under unfavorable meteorological conditions, for periods long enough to guarantee the safety of the plant. 

A complete safety analysis of the MARS nuclear plant has been performed to verify the capability of the plant to guarantee fulfilment of safety objectives and to confront any accidental condition with a frequency of occurrence higher than 1 x 10 year [IV-3],... 

Commercial factors can have a considerable impact on the actual costs of nuclear power stations. Also, as the proportion of electricity generated by nuclear plants becomes more significant, it is Important that these plants are technically capable of operating to suit network requirements. The paper describes the particular features of the SGHWR which make it an attractive system for commercial use. The SGHWR can also be built to operate with natural uranium oxide fuel. The differences between the two versions of the system are briefly outlined. 

Russia continues to operate both the RBMK and VVER type reactors within its borders, and several former members of the Soviet Union also operate these reactor types. Of the over 25 GigaWatts of nuclear power plant capability in Russia in 2015, nearly 50 % was still the RBMK design. The remaining production capacity is dominated by the VVER style. 

There are significant differences between commercial light water nuclear plants and the SRS reactor facilities that will result in substantially less harsh post-accident environments in the SRS facilities. However, the basic concept that equipment must be capable of performing, safety functions under the environmental conditions in which it is relied upon to function remains valid and applicable to the restart of the K-Reactor facility. 

Hafnium neutron absorption capabilities have caused its alloys to be proposed as separator sheets to allow closer spacing of spent nuclear fuel rods in interim holding ponds. Hafnium is the preferred material of constmction for certain critical mass situations in spent fuel reprocessing plants where hafnium s excellent corrosion resistance to nitric acid is also important. 

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