The decision on the pre-schedule closure of Chornobyl NPP was made by Ukraine after signing the Memorandum of Understanding between the Government of Ukraine and Governments of the G7 countries and the Commission of the European Community on December 25, 1995.
Basic information: Post-accident operation and shutdown
On November 29, 2000, the Cabinet of Ministers of Ukraine issued a Decree, which approved the “Comprehensive Program for Chornobyl NPP Decommissioning”. It was a state-level document that defined the content of the decommissioning of the ChNPP Power Units and the transformation of the Shelter Object into an environmentally safe system.
In 2009, the Law of Ukraine "On the National Program for Decommissioning of the Chornobyl NPP and Transformation of the Shelter Object into an Environmentally Safe System" was adopted. The Comprehensive Program 2000 lost its significance and was terminated.
The strategy of “deferred sequential dismantling” SAFSTOR (from SAFe STORage in English – safe storage, storage under surveillance) was selected for the ChNPP.
The SAFSTOR's strategy foresees that NPP with removed nuclear fuel is under control for a certain period, after which the work will be done to fulfil the conditions of the end state established for this site. During the period of such storage, the total level of radioactive contamination of the reactor will be reduced due to the natural decay of some radioactive substances, which will reduce the amount of radioactive materials, which are subject to removal during the final decommissioning stage.
In accordance with the National Program, decommissioning is carried out in 4 stages:
1. Shutdown (preparatory stage for decommissioning, lasted from 2000 till 2015). The stage during which nuclear fuel was removed and transported to the Spent Fuel Storage Facility designed for long-term storage.
2. Final shutdown and preservation of reactor installations (current stage, from 2015 approximately till 2028). The tasks of this stage are as follows:
• Bringing the ChNPP Units to the state that excludes the possibility of using them for power generation.
• Removal of ionizing radiation sources that are subject to control from Power Units.
• Preservation of reactors and the most radioactively contaminated equipment.
3. Safe enclosure of reactor installations for the period during which radioactive contamination should be naturally decreased to the acceptable level (roughly till 2045).
4. Dismantling of reactor installations. During this stage the equipment will be dismantled and the site will be cleaned to ensure maximum release from restrictions and regulatory control (approximately till 2065).
The “Brown spot” state is the final objective of ChNPP decommissioning.
"Brown spot" is a state which actually means cleaning the site and building structures to the level of contamination that corresponds to the contamination within the Exclusion Zone territory around the ChNPP.
Taking into account the particularities of the Chornobyl NPP location and prospects for creation of the Zone of Special Industrial Use within the Exclusion Zone, a concept for further development of the Chornobyl NPP will be developed, in which the end state of the site will be determined as "Industrially developed site". The development of the ChNPP site should not only reduce the burden on the state budget, associated with maintenance of the Exclusion Zone, elimination of consequences of the Chornobyl accident and decommissioning of the ChNPP, but also restore the abandoned land for economic activity and give impetus to economic development of the Polissia region.
For this purpose, it is necessary to efficiently use the following specific features of the Exclusion Zone and the ChNPP industrial site:
• Availability of developed production infrastructure: systems of communications, power supply, physical security, water supply, radiation monitoring, railroad and motor access ways.
• Isolation from centers of population.
• Availability of personnel competent in radioactive material management.
• Location within the Exclusion Zone, being the restricted inhabitation area.
We propose to focus on more active use of the above specific features and potentialities of the ChNPP industrial site and Exclusion Zone for the needs of the nuclear industry of Ukraine, with regard to NPP Units decommissioning and radioactive material management.