MANAGEMENT OF RADIOACTIVE WASTE CHERNOBYL

As a consequence of the accident at the 4th unit of ChNPP a large area in the vicinity of the ChNPP has been contaminated by radionuclides. There are three categories of contamination:

• Particles of irradiated fuel from the reactor core, diameter less than 1 mm, dispersed within a very short period during reactor explosion. They represent the main source (around 90%) of all radioactive contamination in the close vicinity of the 4th unit;
• Micro particles - aerosols (diameter less than 1 micrometer) released from the reactor;
• Contaminated carbon black and microparticles of irradiated fuel, both generated during the reactor graphite fire.

Extensive decontamination and site remediation works were performed in 1986-1987. The radioactive waste, collected during these activities, was placed in 600-800 collection points for temporary storage. Trenches, big diameter dumps as well as engineered facilities were used for placing of the contaminated material. Most of facilities were located close to the center of the 30 km exclusion zone. The radioactive waste stored in the above mentioned waste collection facilities are a very significant source of ground water contamination. In spite of that, verified information on the mass, activity, radionuclide composition, the potential impact to the public and the environment and many other parameters has not been available at sufficient detail even in 1994.

In the aim to contribute to the elimination of one of the most dangerous source of environmental contamination, the EC decided to initiate this project, covering an entire complex of activities, starting from an assessment and an evaluation of waste inventory in the storage dumps, through specification of the equipment for the retrieval and processing of the retrieved waste till the design of the waste storage and disposal facility.

The overall objective of this project was to contribute to the improvement of the management of the radioactive waste at the Chernobyl NPP.

The specific objective of this project was to prepare the on-site remediation activities for the waste dumps in the Chernobyl exclusion zone. The aim was to provide design tools and design documents needed by the Ukrainian authorities for the decision making and licensing process.

The project was implemented in three work packages:

• Assessment of the waste arising, inventory in dumps, present condition and degree of related radiation risk in the medium and long term;
• Definition of the specification for the equipment for treatment and conditioning of the retrieved radioactive waste;
• Design and specification of the engineered surface facilities for disposal of the short lived RAW and for an interim storage of long lived RAW.

In the first, most extensive package of works, the following principal activities were performed:

• Collection and analysis of available data on stored waste and storage facilities characteristics;
• Classification of the storage facilities according the amount of stored waste,the activity level, the risk of ground water contamination, etc.;
• Development of methods for waste dumps assessment;
• Creation of a database, related to this project;
• Assessment of the dose rates and a cost benefit analysis;
• Field activities – detailed examination of each known waste dumps and an inspection of the territory with potential dumped waste;
• Establishment the priorities.

Using the data collected and analysed in the first package, a suitable equipment was proposed for the retrieval and processing (treatment and conditioning) of the waste stored in the dumps. Waste sorting, compaction, incineration and cementation in concrete containers were the main methods considered for the implementation.

The third package was dedicated to the selection and justification of the disposal (long term storage) of the waste, retrieved from the dumps and processed at the facilities proposed in the package two. The site selection, the detailed evaluation of available options and facilities, the design of the surface disposal facility for short lived waste, the design of storage facility for long lived waste and the proposal of containers for disposal of the waste were the principal subjects covered in this package.
The implementation of this project represents a valuable contribution to the solution of one of the critical problems of a potential environmental contamination in the Chernobyl NPP area.

Comments

Quality of the results, Lesson learnt, Recommendations for follow-up

The summary report (available in Russian) describes properly and in sufficient details the results and the achievements of the contractor. The results of the project are sufficiently demonstrated in a narrative as well as a drawing and a table part of the final report.

Results of this project are presented in a clear and concise way and they represent a valuable basis for the radioactive dumps at the ChNPP remediation.

The project fully met the objectives stated in the relevant section of the ToR.

Further Information

Further information on the project results can be found in the Final (summary) report (available in JRC the Petten archive) and sought from the beneficiary organization.

The final report is available at the DG JRC-IE archive.