Provided are a radiation measurement device and method that allow stable radiation measurement as compared with the prior art. The radiation measurement device includes a radiation detection unit 1 having a scintillator, an optical transmission member 21 for transmitting an optical signal generated in the radiation detection unit, and a signal processing unit 3 for calculating a radiation dose from the optical signal transmitted. The signal processing unit includes a compensation unit 7 for obtaining an optical transmission loss amount from a change in wavelength spectrum in the optical signal caused by radiation acting on the optical transmission member and performs compensation-control on the optical transmission loss amount, and outputs a compensated signal.

A method for measuring drop time of a control rod cluster integrated with a rod position measurement device is provided, wherein the method is used to measure the drop time of each control rod cluster, and includes: Si, monitoring a voltage Ua of coils in Group A to capture a rod cluster drop signal; S2, searching a point (tmax, Vmax) with a maximum drop speed or with a local maximum drop speed; S3, retroactively calculating, from tmax, an end of a time period T4 when the control rod cluster starts to drop; S4, retroactively searching, from a minimum value point of a drop reference signal DROPref, a start of the time period T4 when the drop reference signal DROPref drops from a maximum value to 33% thereof; and S5, determining, from tmax forward, a time point t6 when a drop speed of the control rod cluster is lower than 0.

A method for measuring drop time of a control rod cluster integrated with a rod position measurement device is provided, wherein the method is used to measure the drop time of each control rod cluster, and includes: Si, monitoring a voltage Ua of coils in Group A to capture a rod cluster drop signal; S2, searching a point (tmax, Vmax) with a maximum drop speed or with a local maximum drop speed; S3, retroactively calculating, from tmax, an end of a time period T4 when the control rod cluster starts to drop; S4, retroactively searching, from a minimum value point of a drop reference signal DROPref, a start of the time period T4 when the drop reference signal DROPref drops from a maximum value to 33% thereof; and S5, determining, from tmax forward, a time point t6 when a drop speed of the control rod cluster is lower than 0.

A control rod position indication system is for a nuclear reactor with a reactor core and at least one control rod which is movable along a linear path of movement for controlling reactivity of the core. The system includes a permanent magnet mounted on the control rod or a corresponding drive rod, and a number of reed switches arranged around the path of movement in order to be switched by a magnetic field generated by the permanent magnet when passing by. The permanent magnet has a north-south axis whose orientation is constant during movement, and the respective reed switch has a number of reed contacts which are aligned along a longitudinal axis. The longitudinal axis of at least one reed switch is inclined relative to the north-south axis of the permanent magnet, and the angle of inclination has an absolute value within a range from 15 to 65 degrees.

A control rod position indication system is for a nuclear reactor with a reactor core and at least one control rod which is movable along a linear path of movement for controlling reactivity of the core. The system includes a permanent magnet mounted on the control rod or a corresponding drive rod, and a number of reed switches arranged around the path of movement in order to be switched by a magnetic field generated by the permanent magnet when passing by. The permanent magnet has a north-south axis whose orientation is constant during movement, and the respective reed switch has a number of reed contacts which are aligned along a longitudinal axis. The longitudinal axis of at least one reed switch is inclined relative to the north-south axis of the permanent magnet, and the angle of inclination has an absolute value within a range from 15 to 65 degrees.

Non-intrusive error detection techniques for control and shutdown rod position in nuclear reactors, including methods of monitoring digital rod position indication (DRPI) signals of a DRPI system of a nuclear power plant. The methods include acquiring digital rod position signals at a point between a DRPI display cabinet and a DRPI data cabinet of the DRPI system, and processing the digital rod position signals to identify variations in a signal level and a signal timing of the digital rod position signals to determine rod position errors of the DRPI system.

Non-intrusive error detection techniques for control and shutdown rod position in nuclear reactors, including methods of monitoring digital rod position indication (DRPI) signals of a DRPI system of a nuclear power plant. The methods include acquiring digital rod position signals at a point between a DRPI display cabinet and a DRPI data cabinet of the DRPI system, and processing the digital rod position signals to identify variations in a signal level and a signal timing of the digital rod position signals to determine rod position errors of the DRPI system.

A magnetostrictive wire control rod position indicator for determining a real-time position of a control rod using a mutual interference effect between a magnetic field formed by supplying a pulse current to a magnetostrictive wire provided inside a protecting tube and a magnetic field formed by a permanent magnet of a drive shaft includes magnet members installed at an upper limit position and a lower limit position of the magnetostrictive wire control rod position indicator to cause magnetic field interference with the permanent magnet of the drive shaft.

A magnetostrictive wire control rod position indicator for determining a real-time position of a control rod using a mutual interference effect between a magnetic field formed by supplying a pulse current to a magnetostrictive wire provided inside a protecting tube and a magnetic field formed by a permanent magnet of a drive shaft includes magnet members installed at an upper limit position and a lower limit position of the magnetostrictive wire control rod position indicator to cause magnetic field interference with the permanent magnet of the drive shaft.

A rod position indication system includes a drive rod operably coupled to a control rod that is configured to be both withdrawn from and inserted into a reactor core. A number of sensing devices are arranged along a path of the drive rod, and an end of the drive rod passes by or through one or more of the sensing devices in response to movement of the control rod relative to the reactor core. The sensing devices are arranged into a plurality of groups, and each group includes two or more of the sensing devices electrically coupled together. The rod position indication system further includes a control rod monitoring device electrically coupled to each group of sensing devices by a routing wire.