In Situ Study Of The Ar-41 Plume Released From The Ignalina Npp

The Ar-41 gamma ray radiation was registered using the in situ method in the vicinity of the Ignalina nuclear power plant (NPP). The sum of gamma rays, that are reaching the HPGe detector, situated along the wind direction, from a number of plume segments and which are registered in the energy range of about 1.29 MeV, is calculated. An independent technological regime of the operating reactor method of the determination of the Ar-41 emission rate from NPP stack is introduced.