The Chornobyl zone is an exclusion area severely contaminated in the Chornobyl accident. The legislative mode for this area is determined in accordance with Law of Ukraine No. 791а-12.
A series of radiation hazardous facilities are located on the territory of the Exclusion Zone:
Major facilities of Chornobyl industrial site:
- Chornobyl NPP units 1, 2 and 3;
- Shelter and New Safe Confinement (Arch);
- liquid radwaste treatment plant;
- industrial complex for solid radwaste management;
- wet spent fuel storage facility (ISF-1);
- dry spent fuel storage facility (ISF-2).
Major radwaste management facilities in the Exclusion Zone:
- Vektor site (Stages 1 and 2);
- radioactive waste disposal sites (Buriakivka, Pidlisnyi, ChNPP Stage III);
- radioactive waste interim confinement sites.
Facilities to be constructed:
- centralized spent fuel storage facility (centralized SFSF)
ChNPP industrial facilities
All four Chornobyl NPP units are in shutdown state: power unit 2 was shut down in 1986 due to the accident, power unit 2 in 1991, power unit 1 in 1996, and power unit 3 in 2000. Chornobyl NPP units 1, 2 and 3 are currently under decommissioning, and the Shelter is under transformation into an environmentally safe system.
Construction of the Shelter over destroyed power unit 4 ensured protection of the environment against release of radioactive substances and protection of the public and people, primarily those who worked at Chornobyl site, against ionizing radiation. The very short timeframes for Shelter construction at high levels of radiation, use of remote technologies, inadequate strength of the remaining structures at power unit 4, which became supports for the Shelter civil structures, and significant amounts of radioactive materials and fuel determined numerous risks that had to be minimized.
On 12 March 2001, the Interagency Governmental Commission for Comprehensive Solution of Chornobyl Problems accepted the Strategy for Shelter Transformation into an Environmentally Safe System to be implemented in three stages. Stage 1 is aimed at stabilization of Shelter civil structures. Stage 2 deals with construction of the New Safe Confinement. Stage 3 is Shelter transformation into an environmentally safe system.
The civil structures had been stabilized step-by-step from 1998 to 2008 and construction of the New Safe Confinement was started in April 2012. On 29 November 2016, the long-awaited sliding of the New Safe Confinement over the Shelter and Chornobyl NPP unit 4 destroyed in the accident was performed. The Confinement commissioning is planned for the end of November 2017. However, the work will not stop at that stage. The next and final step should be aimed at the development of infrastructure to dismantle unstable structures inside the Shelter and remove fuel-containing materials and radioactive waste for further management and disposal.
Large amounts of solid and liquid radioactive waste with different activity levels accumulated during Chornobyl NPP operation and mitigation of the accident consequences in 1986. The liquid radwaste treatment plant and the industrial complex for solid radwaste management were constructed and are currently under commissioning at the ChNPP site under international technical assistance projects. The implementation of these projects will allow processing and conditioning of the accumulated and generated radioactive waste.
Spent nuclear fuel is currently stored at ChNPP site in the wet spent fuel storage facility (ISF-1) commissioned in 1986. The ISF-1 lifetime expires at the end of 2025. Thus, the new dry spent fuel storage facility (ISF-2) is currently under construction for long-term storage of all spent fuel at ChNPP site. Nuclear fuel transport from ISF-1 to ISF-2 will start after ISF-2 commissioning, planned in the third quarter of 2018.
Facilities in the Exclusion Zone
The Vektor site is located on the territory of the Exclusion Zone.
The Vektor site includes a series of radioactive waste decontamination, transport, processing and disposal facilities. The Vektor construction was started in 1998 in two stages:
- Vektor Stage 1
- Vektor Stage 2
Vektor Stage 1 is intended for disposal of radioactive waste resulting from the Chornobyl accident. Stage 1 startup system includes a facility for radwaste disposal in reinforced concrete containers (SRW-1) and a module-type facility for disposal of radioactive waste in bulk (SRW-2).
Vektor Stage 2 envisages construction of the following:
- centralized near-surface disposal facilities for radwaste generated at operating Ukrainian NPPs and accumulated at the sites of the state specialized radwaste management enterprises of the Radon State Corporation;
- facilities for processing of Chornobyl-origin radioactive waste at Radon sites;
- long-term storage facilities for high-level long-lived radioactive waste;
- centralized long-term spent fuel storage facility.
The construction of the centralized long-term spent fuel storage facility and installation of its systems and equipment were completed in 2015 at the Vektor site.
Facilities for disposal and confinement of large amounts of accident-origin radioactive waste were constructed in the Exclusion Zone during emergency measures aimed at mitigation of the Chornobyl accident consequences in 1986-1987. These facilities include radioactive waste disposal sites called Buriakivka, Pidlisnyi and ChNPP Stage III and radwaste interim confinement sites.
Buriakivka has been in operation since 1987. This disposal site includes 30 near-surface radwaste disposal facilities (trenches). Since the beginning of operation, about 687,000 m³ of Chornobyl-origin radioactive waste has been placed at the Buriakivka site. Potential reconstruction of Buriakivka is currently under consideration as its design lifetime is going to expire.
Pidlisnyi and ChNPP Stage III were created during the first years of Chornobyl accident mitigation. These facilities contained the most hazardous high-level long-lived radioactive waste. The radioactive waste must be further retrieved from these facilities and redisposed in a geological repository.
Nine radioactive waste interim confinement sites are located in the Exclusion Zone: Stantsiya Yaniv, Naftobaza, Pischane Plato, Rudyi Lis, Stara Budbaza, Nova Budbaza, Prypyat’, Kopachi and Chystohalivka with a total area of about ten hectares. Trenches and storage piles with radioactive waste are located on these sites. The radioactive waste interim confinement sites are under continuous survey and the trenches and storage piles are maintained in a safe state.
Facilities to be constructed
The adoption of the Law of Ukraine “On Management of Spent Nuclear Fuel and Siting, Design and Construction of the Centralized Storage Facility for Spent Nuclear Fuel from Ukrainian Nuclear Power Plants with VVER Reactors” on 9 February 2012 legally approved the decision on construction of this facility on the territory of the Exclusion Zone.
On 12 October 2016, the SNRIU Board approved conclusions of the state nuclear and radiation safety review of the Preliminary Safety Analysis Report for the Centralized SFSF.
Active preparation for facility construction is currently underway. The centralized SFSF will be constructed to decrease energy dependence from the Russian Federation. It should be recalled that Ukraine spends annually about 150-200 million dollars for spent nuclear fuel transport for storage and reprocessing to the Russian Federation.