ISPS equipment

Project goal: 

Provision of reliable and safe operation of  power Units Nos.1, 2 of Novovoronezh NPP-2, which is achieved by protecting the power Unit from design-basis accidents, occurring in the result of seismic influences (earthquakes), by reactor plant transferring into safe state in order to prevent an accident at the early stage.

ISPS is a completed part of automated process control system (APCS) of power Units Nos.1, 2 of Novovoronezh NPP-2, and jointly with control and protection system (CPS) it performs generation of signals for automatic reactor shut-down at an earthquake which exceeds the level of design-basis value.

ISPS is designed for power Units Nos.1, 2 of Novovoronezh NPP-2 with four-loop reactor plant with water-water power reactor WWER-1200 (V392-M) of electric power equal to 1200 MW.

ISPS consists of two independent sets.

Composition of each set includes the following devices and units: 

  • Three channels for measurement of seismic influences, implemented on the base of three-component seismic sensors SD4;
  • Three commutation units (BKK) for multiplication and transfer of signals, coming from SD, to transport-technological equipment (TTE), to data display and logging hardware (DDLH) and equipment of TELEPERM XS (TXS);

ISPS provides the following:

  • measurement of seismic influences on reactor plant (RP);
  • generation of discrete signals of emergency protection (EP) at exceeding of assigned emergency level of seismic influence threshold;
  • generation of discrete signals for start of registration at exceeding of assigned preventive level of seismic influence;
  • generation of analogue signals on acceleration values by coordinates X, Y, Z, and general analogue signals corresponding to absolute value of seismic acceleration;
  • generation of discrete signals on failure of ISPS channels.

The range of analogue signals is (4-20) mA. The type of discrete signals: group of relay commutating contacts at current within the range up to 100 mA and supply voltage of 24 V.

Structural diagram of ISPS set:

 

Structural diagram of ISPS set

Each ISPS channel performs diagnostics of intrinsic technical means. At failure of channel (at malfunction), at disconnection of electric supply the signal, equivalent to emergency protection signal, is generated.