State Specialized Enterprise " Chernobyl NPP" ensures maintenance in safe condition shutdown Units 1, 2, 3, "Shelter" object and facilities of Chernobyl NPP’s industrial site. Chernobyl NPP is located at Exclusion Zone territory with high levels of radioactive contamination. ChNPP structure includes three Units with RBMK – 1000 reactor installations with electric capacity 1000 MW each, "Shelter" object - engineering construction localizing destroyed as a result of beyond designed accident Unit 4, spent nuclear fuel storage, RAW storage, starting-up reserve heating plant, a cooling pond and other facilities and systems of an infrastructure.
Unit 1 was finally shut down on November 30, 1996.
The reactor facility is brought into “finally shut-down” state. On September 28, 2013, the activities on Unit 1 release from conditioned spent nuclear fuel were completed.
Unit 2 was shut down on October 11, 1991, due to the fire in the Turbine Hall.
The reactor facility is brought into “finally shut-down” state. On November 30, 2012, the activities on Unit 2 release from conditioned spent nuclear fuel were completed.
Unit 3 was shut down on December 15, 2000, according to the Decree of the Cabinet of Ministers of Ukraine “On pre-schedule shutdown of Unit 3 and final shutdown of Chernobyl NPP”.
The reactor facility is brought into “finally shut-down” state. In August 2010, the activities on Unit 3 release from conditioned spent nuclear fuel were completed. In December 2012, Unit 3 status was changed. It was recognized a facility relating to radioactive waste management by a decision agreed with the State Nuclear Regulatory Committee of Ukraine.
Shelter Object represents the set of the constructions formed from damaged constructions of Unit 4 and from constructed after the accident new constructions and systems serving for the monitoring and post accidental situation management. The "Shelter" object is determined as destroyed by beyond designed accident Unit 4 on which immediate measures on accident consequences elimination and on its condition monitoring assurance are executed by Decision of the State Regulatory Body. According to the document "Radiation Safety Norms of Ukraine (RSNU-97/D-2000) the "Shelter" object is classified as: "temporary surface storage (temporary storage) of unorganized RAW".
Fuel Containing Materials condition monitoring and radionuclides content in air, water and air stream (approximately 20000 samples per year), the monitoring of a building constructions condition, the radiation-technological monitoring are provided at the "Shelter" object. Data of information measuring system "Finish", FCM monitoring system "Signal" are used with the purpose of the "Shelter" Nuclear and Radiation Safety monitoring. Experimental system " Pilot " is in operation.
It is provided procedural maintenance of the Shelter object - dust suppression in destroyed reactor (12 times per year) and in Shelter’s premises, dust suppressive compositions application, decontamination of premises, equipment, surrounding territory, maintenance and repair of the equipment.
All current and transforming activity at the Shelter object is aimed on protection of the personnel, the population and an environment against influence of radioactive materials, presenting in the Shelter and on its industrial site.
The shutdown Chernobyl NPP remains to be a Nuclear Facility. In the view of Safety it continues to be in the same legal and procedural environment as an operational nuclear plants.
The principal goal of the State Specialized Enterprise “Chernobyl NPP” consists in Nuclear and Radiation Safety assurance during all stages of Units decommissioning and Shelter object transformation into ecologically safe system.
The decision on Power Units decommission and Chernobyl NPP final closure has been made before Units design resource exhausting, that has no analogues in domestic nuclear engineering practice. Normative base of Ukraine and branch standards in sphere of nuclear installations decommissioning require subsequent improvement and development with the purpose of more complete requirements regulation to NPPs life cycle stages and to kinds of activity, implementing by operating organization during these stages.
In connection with absence not only national but also world experience in liquidation of accidents consequences similar to the accident of 1986, Shelter object transformation into ecologically safe system is the most difficult task. Shelter object’s peculiarity is presence of Fuel Containing Materials, representing long-term hazard for the actual and future generations in its premises.
ChNPP decommissioning demands parallel performance of works on Units preparation for decommissioning and decommissioning. That includes construction of necessary facilities for Spent Fuel (SF) and RAW Management, new technologies and equipment application, Shelter object stabilization measures realization, necessary normative and technical, design and operational documentation development and so forth.
Administration of the enterprise has made a statement on a policy in the Safety and Quality field. It is noted in it, that top priority for all officials there is a Nuclear and Radiation Safety assurance during all kinds of activity performance. Chernobyl NPP assures, that nuclear materials, the equipment, technologies will be used exclusively in the peace purposes and with minimally allowable influence on an environment.
Safety on the Chernobyl NPP site is a high-priority. Notwithstanding the fact that the ChNPP Units are shutdown and do not generate power now, they still pose a nuclear and radiation hazard. With the objective to promote the already achieved level of safety at the Chernobyl NPP, the following set of activities to maintain safe condition of the power units is being performed:
- maintaining operating condition of safety-important and process control systems, testing the systems in accordance with the requirements stated in regulations and specifications;
- operation of systems and equipment in strict adherence to the requirements of technical specifications and manufacturer’s instructions;
- maintenance of the required temperature and humidity conditions in buildings and structures;
- maintenance and routine repairs of equipment as frequently as established by regulations and specifications;
- maintenance of the already created fire prevention conditions on the pant’s site;
- ensuring an appropriate sanitary and access control, including a system of barriers on the ways of - radionuclides’ possible carry-over beyond the SSE ChNPP and Exclusion Zone boundaries;
- ensuring radiation monitoring of the facilities and technology, including but not limited to:
- in-process radiation monitoring;
- radiation dosimetric monitoring;
- radiation monitoring of the protective barriers’ condition;
- control over non-proliferation of radioactive substances;
- radiation monitoring of the environment.
- strict adherence to the already established reference levels for a radiation well-being;
- continuous effort towards maintaining proficiency and qualification upgrades of the personnel.
Both the SSE ChNPP management and independent supervisory bodies strictly control fulfilment of safety assurance activities. Over the past few years, no accidents or emergencies, cases of an unauthorised elevated exposure to personnel and carry-over of radioactive substances beyond the design-basis boundaries were registered at the Chernobyl NPP site.