Development of simulated-gas standards

Multigamma simulated-gas standards were developed for monitoring the surrounding air at nuclear power plants by several commercial firms and laboratories. The main advantages of our simulated-gas standard consist of the easy preparation, gravimetrically spiking the matrix with a standardised multigamma radioactive solution, and that it does not require to be tested against actual gas standards. Self-attenuation correction factors for low γ-ray energies were calculated. Original studies about the stability of the adherence of the dried radioactive residue to the matrix are presented and discussed.