The specific objective of the project is to evaluate radionuclide contamination in the IFIN-HH VVR-S nuclear research reactor building by combining gamma spectroscopy for data acquisition and numerical modeling using the AMBER and RESRAD numeric coding platform.
The project will include 2 stages:
Stage 1: Characterization of the transport properties of the concrete of the reactor building including potential sorption properties and obtaining and characterization by gamma spectrometry of the concentration of radionuclides in different locations in depth in the concrete of the reactor building.
In order to perform the numerical calculations related to the transport of radionuclides in the concrete material of the reactor building, the physical and chemical data representing the transport properties of the concrete considered will be obtained. These properties include at least one porosity and the potential retention property of radionuclides.
Data collection will include sampling of contaminated concrete, as well as characterization of radionuclide concentration by gamma spectrometry. The radiological characterization carried out in 2006 showed that there was a high potential for contamination in room 30 (pump room) and room 31 (in the room below the reactor). As a result, these areas were classified as Class 1 areas. Since the VVR-S reactor was shut down in 1997, only radionuclides with a half-life of more than 1 year will make a significant contribution to the radionuclide inventory. These radionuclides can be classified into the following categories: (i) beta-gamma emitters; (ii) alpha emitters; (iii) difficult-to-detect. Most of the radioactive contaminants generated in the operation of the reactor are beta-gamma emitters. They can be easily detected by beta-gamma scanning and spectrometric gamma measurements.
Stage 2: Modeling the transport of radionuclides in the concrete of the reactor building using the AMBER and RESRAD platforms and validation of the collected data.
This step will include the numerical modeling of the radionuclide transport in the concrete of the reactor building using the experimental data obtained from laboratory measurements. Depending on the accuracy of the simulation, additional samples may need to be collected and the interaction between the model and the data collected will be performed. In the numerical modeling of interest are high are the flow and transport of contaminants in saturated and unsaturated areas.