The history of the storage facility
The Maišiagala Radioactive Waste Storage Facility was constructed in Bartkuškis Forest in 1963. It is situated 9 km away from the town of Maišiagala and 40 km away from Vilnius.
The Maišiagala Storage Facility is a cast-in-situ vault of 200 m3 capacity constructed at a depth of 3 m. Radioactive waste used to be placed into it and then covered with liquid concrete. The concrete absorbs and contains radionuclides as well as prevents water from leaching them from the waste and transferring elsewhere. Storage facilities of this type were constructed at numerous sites of the former Soviet Union and Eastern Europe.
Radioactive wastes generated at industrial, medical and scientific research facilities were accumulated at the Maišiagala Storage Facility. They were brought there not only from Lithuania but also from the Kaliningrad and Grodno Regions.
Radioactive wastes were accumulated at the Maišiagala Storage Facility until 1989. Afterwards the decision was taken to close it as it did not meet modern environmental protection requirements. The wastes there were not sorted, i.e. long-lived and short-lived wastes used to be accumulated in the same place. In accordance with modern requirements wastes of each type must be disposed of separately, in special packages and in expressly constructed repositories. At the time of closure some 60 percent of the facility was filled, i.e. it contained approximately 120 m3 of radioactive waste. The remaining space was filled with sand, covered with concrete, bitumen, asphalt and a thick layer of soil.
Prior to 2002, scientists from the Institute of Physics supervised the Maišiagala Storage Facility. Since 2002, the Radioactive Waste Management Agency (RATA) has been taking care of the facility. RATA is responsible for the supervision and environmental monitoring of the facility. Environmental monitoring consists in systematic observation, assessment and forecasting of soil, water and vegetation. The monitoring is conducted with a view to ascertaining that radionuclides do not “flee” from the facility to the soil or ground water. It was discovered that negligible amounts of tritium, one of the least dangerous radioactive substances, did enter the water of the observation wells expressly drilled in the vicinity of the repository. However, the tritium levels were found to be relatively low and not to exceed permissible levels. The tritium had not reached even the nearest water bodies or the wells of local population. Nevertheless this was an indicator that protection barriers of the facility inherited from the Soviet times needed strengthening in order to prevent radioactive substances from escaping into the environment. Therefore in December of 2002, the European Commission allocated funds and approved the PHARE project Safety Assessment and Upgrading of Maišiagala Repository.
Support from the European Union and other countries
The main objective of the PHARE project Safety Assessment and Upgrading of Maišiagala Repository funded by the European Commission consisted in enhancing radiological safety of the facility. The project was completed in 2006. It consisted of three parts: 1) safety analysis of the facility’s current condition; 2) supply of environmental monitoring equipment; and 3) construction work.
In the course of safety analysis, environmental studies of the Maišiagala Storage Facility were conducted and their results assessed. The work was done by experts from THALES and ANDRA, the French companies that have considerable experience in radioactive waste management, jointly with specialists from the Lithuanian Energy Institute and the Institute of Physics. The data of previously conducted environmental observations was compared with the results of newly conducted studies. The conclusions of the safety assessment analysis were used for producing the design of the repository’s new protection barriers.
Different devices intended for monitoring the repository’s environment and ensuring physical protection were purchased in the course of implementation of the PHARE project. The radiation background, i.e. the radiation level around the facility, will be measured with the environmental monitoring devices. The devices intended for ensuring physical protection (video cameras, motion-sensitive cables) will make it possible to watch and survey the facility’s area and protect against the potential terrorist threat.
Installation of new protection barriers at the facility was the key stage of the project. Additional protection barriers, a system consisting of soil and two water-impervious membranes, were constructed above the vault of radioactive waste in accordance with the design produced by French specialists. The barriers will protect radioactive wastes in the repository from water, which is very important in preventing radioactive substances from entering the environment with water.
The entire area of the repository was surrounded with a special double fence, with motion-sensitive cables placed between the two rows of the fence. All these precautions ensure physical protection of the repository, i.e. they prevent the access of unauthorized persons to the radioactive waste.
The US Energy Department has significantly contributed to upgrading of physical protection at the Maišiagala Repository. In 2004, the Department helped develop and install the system of continuous surveillance at the repository. With the system in operation, the facility can be watched from RATA headquarters and from the Chief Police Commissariat of Vilnius City. Therefore if an incident occurs or there is a threat of danger, it is possible to act at once and take the necessary measures.
According to experts’ conclusions, the Maišiagala Storage Facility will pose no danger as long as it is adequately supervised, i.e. its environment is monitored and the territory is guarded.
Supervision and environmental monitoring of the repository
RATA in cooperation with French specialists developed the program of the repository’s environmental monitoring. The objective of the environmental monitoring consists in watching the changes in the condition of the radioactive waste repository in order to ascertain whether or not it meets the set requirements. Ten wells were drilled for monitoring the repository’s environment. Water samples are taken from the wells on a regular basis. In compliance with legal and standard documents of the Republic of Lithuania, RATA ensures that samples are taken from the repository’s environment on time, and that the samples are analyzed and results obtained are processed. Furthermore, RATA sees to it that reports on analyses are produced and circulated, and that the data of analyses is accumulated. Should any symptoms of contamination be observed, the necessary steps to eliminate it must be taken.
The reports on the results of the environmental monitoring are published on a quarterly basis on RATA website atwww.rata.lt.
RATA has been supervising the Maišiagala Storage Facility in accordance with the requirements of the license Conducting supervision of the closed Maišiagala Storage Facility of radioactive waste issued by the State Nuclear Power Safety Inspectorate (VATESI) on 26 May, 2006.
The future of the Maišiagala Storage Facility
The volume of the repository inherited from the past is relatively small, 120 m3. However, the radioactive wastes stored here are of different types, viz. short-lived very-low level, short-lived low- and intermediate-level, long-lived and very-high-level. For disposal wastes must be sorted, placed in special packages and disposed of separately, in repositories expressly constructed for each type of waste.
Specialists have concluded that the Maišiagala Storage Facility cannot be the site of the final disposal of this kind of waste. Therefore a decision should be taken in the future regarding when and to what site of final disposal the waste should be taken.