Provided is a control rod motion monitoring method and a control rod motion monitoring system, in which a control rod insertion in an entire core is monitored at all time during operation of a reactor and, when an abnormality occurs, a signal is issued to a countermeasure device that automatically starts operation and an alarm is issued to prompt operation of an operator. An LPRM detector in an LPRM assembly of the entire core is divided into four channels for each height; indicated values are averaged at all time; the average indicated value is compared with a set point; and a signal is issued to a countermeasure device when an abnormality occurs.

A nuclear power system includes a reactor vessel that includes a reactor core mounted therein. The reactor core includes nuclear fuel assemblies configured to generate a nuclear fission reaction. The reaction vessel does not include any control rod assemblies therein. The nuclear power system further includes a riser positioned above the reactor core, a primary coolant flow path, a primary coolant that circulates through the primary coolant flow path to receive heat from the nuclear fission reaction and release the received heat to generate electric power in a power generation, and a control system communicably coupled to the power generation system and configured to control a power output of the nuclear fission reaction independent of any control rod assemblies.

A rod position indication system is disclosed. The rod position indication system includes first coils and second coils disposed around a drive rod travel housing in an alternating arrangement, a first data encoder unit connected to each of the first coils and configured to generate a first reference signal, a second data encoder unit connected to the each of the second coils and configured to generate a second reference signal, and a processing circuit in signal communication with the first and second data encoder units. The processing circuit is configured to generate a logic comparison of the first and second reference signals, generate a logic signal based on first position data and second position data, and perform a logic operation on the logic signal and a result of the logic comparison.

A rod position indication system is disclosed. The rod position indication system includes first coils and second coils disposed around a drive rod travel housing in an alternating arrangement, a first data encoder unit connected to each of the first coils and configured to generate a first reference signal, a second data encoder unit connected to the each of the second coils and configured to generate a second reference signal, and a processing circuit in signal communication with the first and second data encoder units. The processing circuit is configured to generate a logic comparison of the first and second reference signals, generate a logic signal based on first position data and second position data, and perform a logic operation on the logic signal and a result of the logic comparison.

A nuclear power reactor may include a plurality of power modules, each including a nuclear fuel and a power conversion system configured to convert heat generated from the nuclear fuel to electricity, where the nuclear fuel of the plurality of power modules collectively forms a reactor core. The nuclear power reactor may also include a sleeve being disposed between the plurality of power modules, where the sleeve has a first end and a second end opposite to the first end. The nuclear power reactor may further include a reactivity booster having a neutron source and a reactivity quencher having a neutron absorber. The reactivity booster may be movable between a first location adjacent the first end of the sleeve and a second location adjacent the reactor core, and the reactivity quencher may be movable between a third location adjacent the second end and the second location adjacent the reactor core.

A nuclear power reactor may include a plurality of power modules, each including a nuclear fuel and a power conversion system configured to convert heat generated from the nuclear fuel to electricity, where the nuclear fuel of the plurality of power modules collectively forms a reactor core. The nuclear power reactor may also include a sleeve being disposed between the plurality of power modules, where the sleeve has a first end and a second end opposite to the first end. The nuclear power reactor may further include a reactivity booster having a neutron source and a reactivity quencher having a neutron absorber. The reactivity booster may be movable between a first location adjacent the first end of the sleeve and a second location adjacent the reactor core, and the reactivity quencher may be movable between a third location adjacent the second end and the second location adjacent the reactor core.

Various example embodiments are directed towards an improved control drum, as well as systems, apparatuses, and/or methods for operating a nuclear reactor with a plurality of improved control drums. The control drum includes an outer shell, an inner shell, a plurality of tubes, the plurality of tubes including at least one neutron absorbing tube and at least one neutron scattering tube, and at least one baffle plate arranged between the outer shell and the inner shell, the at least one baffle plate including a plurality of perforations, and at least one perforation of the plurality of perforations configured to support a tube of the plurality of tubes.

Various example embodiments are directed towards an improved control drum, as well as systems, apparatuses, and/or methods for operating a nuclear reactor with a plurality of improved control drums. The control drum includes an outer shell, an inner shell, a plurality of tubes, the plurality of tubes including at least one neutron absorbing tube and at least one neutron scattering tube, and at least one baffle plate arranged between the outer shell and the inner shell, the at least one baffle plate including a plurality of perforations, and at least one perforation of the plurality of perforations configured to support a tube of the plurality of tubes.

A method regulates operating parameters comprising at least the mean temperature of the core (T.sub.m), and the axial power (AO) imbalance.The method includes development of a vector (Us) of control values of the nuclear reactor by a supervisor (31) implementing a predictive control algorithm; development of a vector (u.sub.K) of corrective values of the nuclear reactor controls by a regulator (33) implementing a sequenced gain control algorithm; development of a vector (U) of corrected values of the commands of the nuclear reactor, by using the vector (U.sub.S) of the values of the commands produced by the supervisor (31) and the vector (U.sub.K) of the corrective values of the commands produced by the regulator (33); and regulation of the operating parameters of the nuclear reactor, by controlling actuators using the vector (U) of the corrected values of the controls.

A nuclear power system includes a reactor vessel that includes a reactor core that includes nuclear fuel assemblies configured to generate a nuclear fission reaction. A representative nuclear power system further includes a riser positioned above the reactor core and a primary coolant flow path that extends from a bottom portion of the reactor vessel, through the reactor core, and through an annulus between the riser and the reactor vessel. A primary coolant circulates through the primary coolant flow path to receive heat from the nuclear fission reaction and release the heat to a power generation system configured to generate electric power. The nuclear power system further includes a control rod assembly system positioned in the reactor vessel and configured to position control rods in only two discrete positions.