The invention relates to a nuclear plant in which the power of a nuclear reactor is controlled via demand of a connected electric grid. A naturally circulating nuclear reactor coolant loop is linked to a water/steam loop by means of a steam generator. The water/steam loop consists of an electric power generating unit and a water recirculating and steam control system. The generator is coupled to an external power grid. As power requirements of the grid change, a controller linked to the generator and a three way valve divides steam flow between the expansion turbine and a feedwater heater to boost or retard the power output. Altering the steam flow changes the pressure and temperature in the water/steam system and thus the coolant flow rate. The change in coolant flow allows the reactor core to regulate its reactivity to reach a state of equilibrium to the demand for electric power.

The invention relates to a racking device for storing and/or transporting nuclear fuel assemblies, including first stages (Ei1, Ei+1) for neutron absorption and thermal conductivity, as well as second stages (E2i) for mechanical strength arranged so as to alternate with the first stages, each first stage (Ei1, Ei+1) including first and second assemblies having interlacing notches (6a, 6b) made of aluminium alloy including boron, and each second stage (Ei) comprising first and second structures (7a, 7b) stacked in the stacking direction (8) and each made of one or more materials which are free of neutron-absorbing elements, the structures (7a, 7b) being free of notches on the opposite edges thereof in the stacking direction (8).

Provided is a small nuclear power generator which restores steam to water by applying pressure to the inside of a condenser using a pressurizer disposed over the condenser without condensing steam using cooling water. The small nuclear power generator includes: a nuclear reactor generating high-temperature heat by nuclear fission of a nuclear fuel; a steam generator converting internal water into steam by the high-temperature heat generated in the nuclear reactor; a turbine/generator including a steam turbine rotated by steam generated in the steam generator and a generator connected to an axis of the steam turbine and together rotating to produce electricity; and a condenser restoring steam to water by applying pressure to steam discharged after rotating the steam turbine using two or more pressurizers, again supplying the water into the steam generator, and formed of a titanium (Ti) or an alloy thereof.

Provided is a small nuclear power generator which restores steam to water by applying pressure to the inside of a condenser using a pressurizer disposed over the condenser without condensing steam using cooling water. The small nuclear power generator includes: a nuclear reactor generating high-temperature heat by nuclear fission of a nuclear fuel; a steam generator converting internal water into steam by the high-temperature heat generated in the nuclear reactor; a turbine/generator including a steam turbine rotated by steam generated in the steam generator and a generator connected to an axis of the steam turbine and together rotating to produce electricity; and a condenser restoring steam to water by applying pressure to steam discharged after rotating the steam turbine using two or more pressurizers, again supplying the water into the steam generator, and formed of a titanium (Ti) or an alloy thereof.