Further considerations for the setting up of a low background whole-body counter for internal dosimetry at Waste Isolation Pilot Plant (WIPP) Carlsbad, NM, USA: transmitted photon component

Abstract

One of the further considerations in the present work, while setting up a low background whole-body counter (WBC) underground at the Waste Isolation Pilot Plant (WIPP) is to reduce the background in the energy region of interest <100 keV. The goal of the present work is to determine the adequacy of a chamber located underground at WIPP of dimensions 1.83 m × 1.22 m at the base, 1.83 m high, with 15 cm thick pre-world-war II steel shielding. The objective of the present work is to estimate the transmitted photon flux into this chamber for setting up the low background WBC. The transmitted photon flux is simulated with the GEANT code for an incident photon flux consisting only of 1461 keV photons. The results are discussed with respect to a detector of choice for detecting <50 mBq emitting photons in the energy region <100 keV.