SPNDS (Self Powered Neutron Detectors)

Self-Powered Neutron Detectors have been used effectively as in-core flux monitors for over twenty-five years in nuclear power reactors worldwide. The typical SPND is a coaxial cable consisting of an inner electrode (the emitter), surrounded by insulation, and an outer electrode (the collector).


Various types of SPND emitters are used in power reactor application

  1. Inconel 600
  2. Rhodium (Rh103
  3. Vanadium (V51)
  4. Platinum (Pt195)
  5. Cadmium (Cd)

General Characteristics

  • Need no power supply
  • Simple and robust structure
  • Relatively small mechanical size desired for in-core installation
  • Good stability under temperature & pressure conditions.