Dose rate assessment in complex geometries

Abstract

A code developed for calculating dose rate maps in scenarios with complex geometries and gamma radiation sources is presented in this work. It is based on the point kernel method. The code computes photon flux and dose rate in preselected positions due to volumetric radioactive sources in the presence of other nonemitting materials acting as shielding. Buildup factors are considered to account for radiation scattering effects, using the Geometric-Progression formula in the fitting function. The major advantage of this code is that there are no constraints for the generation of geometries. Any type and number of volumes can be loaded to generate the scenario by using standard three-dimensional computer-aided design tools. The geometry is imported as a DXF format file. In a second step, material and radiometric attributes are imported for each volume. Volumetric radioactive sources are represented by a set of single emitting point sources distributed within its geometry. The code output has been verified in three different ways: by comparing with results from other point-kernel packages, by comparing with estimates obtained with a Monte Carlo code, and by contrasting with direct experimental measurements. Results of these comparisons are presented and discussed. Finally, intrinsic limitations of the code are discussed.Index Terms-Dose rate calculation, point kernel, three-dimensional (3-D) modeling.

Virtual reality-based adaptive dose assessment method for arbitrary geometries in nuclear facility decommissioning

“…The third set of experiments was designed to illustrate the performance accuracy of VRBAM compared with VRBM and MCNP. Three basic scenarios were considered in the experiment, and they were: (A) no shielding, (B) shielding scenario, both of which were already used as benchmark scenarios in dose rate experiments in CIDEC (Vela et al 2006) and VRBM (Chao et al 2018), (C) surface-source scenario. The results from MCNP were generated by running the code for two hours and those from VRBAM and VRBM are averaged over 100 simulations.…”

“…It often uses Monte Carlo techniques to obtain parameters and select source points, and it treats radiation transport deterministically. These methods have been exploited by many researchers (Breismeister 2000, Vela et al 2006, Chao et al 2018.…”

“…The traditional solutions build the geometric space by combining geometry specification and manual modeling, so it is difficult and inefficient to describe complex geometries that apply in dynamic environments. In order to model complex geometries efficiently, Vela et al (2006) took advantage of the modeling capabilities of computer-aided design (CAD) tools to construct the geometry and represent the volumetric radiation source with regular grid points; the code CIDEC was developed based on the point kernel method to assess dose rates in complex geometries. It can only deal with volumetric sources, and the accuracy of the method is ensured up to the grid resolution.…”

A Variable Point Kernel Dosimetry Method for Virtual Reality Simulation Applications in Nuclear Safeguards and Security

“…This second test compares dose rate results for a specific setup already used as a benchmark case in previous Dose rate experiments published in this journal [13].…”

“…Alternatively, the deterministic PK methods can be used [11,12,13]. They are well known in the scientific community, and in particular in the nuclear physics field.…”