After Chernobyl disaster a number of sites in the vicinity of ChNPP were contaminated. The radioactive waste from the Unit 4 as well as from the nearby territory was dug in a lot of trenches and piles designated as temporary facilities, later called dumps. Some of the dumps were unknown at the time of project initiation. However, the detailed information related to this dumps is essential for any safety, ecological and radiological analysis as well as for any further activity, like retrieval and processing of the waste.
Therefore, the Ministry for Chernobyl affairs started in 1993 a very detailed programme to characterize the dumps and estimate and investigate the radioactive inventory. After the first step of the investigation work, it has been recognised that classical methods, like drilling, taking samples and laboratory analysis, are not sufficiently effective for investigation of such a huge number of dumps.
Therefore, after successful preliminary tests, the Ground Penetrating Radar (GPR) was tested and proved to be an effective method for given purpose. GPR technology was expected to support the following:
- localize the radioactive waste dumps;
- characterize the content of the drums;
- define the depth of the underground water.
The TACIS project P 234, aimed at the facilitation of implementation of GPR technique at ChNPP; it a follow up of the previous TACIS project UR/029.
The overall objective of this project was to contribute to minimization of potential consequences of radioactive contamination in the vicinity of ChNPP, in particular, in improving the inventory of radioactive waste in dumps in the Chernobyl exclusion area.
The specific objective of the project was to make Ground Penetrating Radar (GPR) technique available to the organizations and experts in charge of investigation and clean up the territory and also to provide the experts with relevant training on GPR system to study the radioactive waste dumps. In addition to that, it was to be verified whether this system was applicable to the specific site conditions (soil, waste types, etc.)
Achievements (With reference to the TORs)
The project was implemented in four tasks:
- Equipment supply: A ground penetrating radar (GPR) of type SIR-2, two antennas (500 MHz and 300 MHz), software and other accessories, providing for a complete radar prospecting, were provided to the beneficiary.
- Practical and theoretical training for Ukrainian staff was offered through relevant training course. Besides basic training in operation of the GPR, also practical application in the field was provided.
- On the job training was arranged for selected staff to assure correct routine use of the GPR on the site in the Chernobyl exclusion zone, processing and correct interpretation of the data for the specific purpose of the radioactive material damps investigation.
- Co-ordination with the previous TACIS project UR/029 provided for logical continuation of the works and assured significant contribution to completion of the data base of radioactive waste in Chernobyl exclusion zone, established in the previous TACIS project.
In the testing trial of the system it was demonstrated that:
- The GPR can be used to detect with sufficient reliability geometric parameters of the dumps (up to depth 5-7 m), ground water level, metallic structures in the dumps (up to depth 5-7 m) and large reinforced concrete structures (up to depth 4-5 m);
- Identification of waste type – soil, wood, debris – in the dumps is difficult by the GPR (low reflection)
- GPR is not suitable for the inspection of sites, covered with clays and clays minerals.
(Quality of the results, Lesson learnt, Recommendations for follow-up)
The final report properly describes the process and achievements of the contractor, results of the project are sufficiently demonstrated. Results of the project are presented in clear and concise way and they are a good basis for implementation of GPR technique for required purpose in Chernobyl exclusion zone.
The project fully met the objectives stated in the TORs.
Further information on the project results could be sought from the Final report (available in JRC Petten archive) and from beneficiary organizations.
The Project Final report is available at the JRC-IE archive.