Passiv Autocatalytic Recombiner - NIS-PAR

Optimum hydrogen control under all conditions

Passive Autocatalytic H2 Recombiners are an economical and effective solution to mitigate the effects of hydrogen release during postulated accidents in nuclear power plants. The NIS-PAR is also an efficient solution to deplete hydrogen in other facilities where hydrogen comes from from radiolysis or another source. As a result, explosions will be securely prevented.

The NIS-PAR works completely passive and is self-starting also at low temperatures and under wet conditions. The catalytic material palladium is applied on the spherical surface of pellets made from aluminum oxide with a diameter of about 4-6 mm. It is filled in cartridges made from slotted stainless steel sheets. Depending on the NIS-PAR type, different numbers of such cartridges are arranged vertically in a stainless steel housing. A hood protects against spray water, chimney elongations boost the depletion rate.

 

Global test programs

Up to now a large number of international test programs were conducted with the NIS-PAR module, which verify the development results:

  • NRC im Sandia National Laboratory /USA

  • Consolidated Edison im Wyle-Laboratory/USA

  • EPRI/EDF in der KALI-H2-Testeinrichtung der CEA in Cadarache/ Frankreich

  • EDF im IPSN in Cadarache/Frankreich

  • EG und NIS im Model Containment von Battelle-Frankfurt

  • Toshiba/Hitachi in Japan

  • OECD in der THAI-Versuchsanlage Frankfurt

Module variants

There are various NIS-PAR module options for the flexible adaption to the local needs and for the needed H2 depletion rates in the NPP. NIS delivers complete solutions from one hand:

  • Planning

  • Necessary model calculation

  • Assistance with approval procedures

  • Manufacturing and delivery

  • Assembly

  • Training of operating staff for conduction of periodic inspections

 

For periodic inspections we supply an easy to use test device for the cartridges filled with catalytic material. The cartridges can be easily removed from the housing through the inspection hatch.

References

In Germany NIS-PAR modules are utilised in:

  • NPP Gundremmingen
  • NPP Philippsburg
  • NPP Biblis

Worldwide, NIS-PAR modules are utilised in:

  • NPP PAKS, 4 units, Hungary
  • NPP Indian Point 2, US
  • NPP Surry I, US
  • NPPs Kashiwazaki-Kariwa, Onagawa, Higashidori, Shimane, Shika, Japan
  • NPP Krsko, Slovenia
  • NPP Vogtle, United States
  • NPPs Asco and Vandellos, Spain
  • NPP Temelin, Czech Republic
  • NPP Zaporizhia, Ukraine
  • Special NIS recombiners are also used in CASTOR® casks for wet storage of spent fuel elements.