The Chornobyl Exclusion Zone and the unconditional (obligatory) resettlement area are the territory contaminated by radionuclides after the Chornobyl catastrophe, from which the public was evacuated and resettled during the first years after the accident. The Exclusion Zone contains a significant amount of radioactive waste and waste management facilities, Chornobyl NPP under decommissioning and the Shelter being converted into the safe system. Due to the significant amount of waste accumulated from the ChNPP accident in 1986, and waste that was and will be generated during ChNPP decommissioning and the Shelter conversion into the environmentally safe system, the comprehensive infrastructure for management of spent nuclear fuel and radioactive waste is created in the Exclusion Zone to ensure safe management of spent nuclear fuel and radioactive waste from their retrieval to long-term storage and disposal. Two national programs are ongoing to ensure the above tasks, including the radioactive waste management infrastructure: the National Program for Chornobyl NPP Decommissioning and Shelter Conversion into the Environmental Safety System and the National Targeted Environmental Program for Radioactive Waste Management.

The urgent task for nuclear energy of Ukraine is to perform tasks on decommissioning of Chornobyl NPP units.

Chornobyl NPP Units No. 1, 2, 3 are at the stage of operation termination. The activity at these power units is regulated by conditions of the SNRIU license EO 000040 dated 22 March 2002 to take efforts on decommissioning of Chornobyl NPP nuclear facilities.

On 01 January 2010, the Law of Ukraine “On National Program for Chornobyl NPP Decommissioning and Shelter Conversion into the Environmental Safety System” came into force.

According to the National Program for Chornobyl NPP Decommissioning and Shelter Conversion into the Environmental Safety System, measures for the Shelter are aimed at its conversion into the environmental safety system. The task on conversion of this facility is solved through successive development and fulfillment of certain plans, projects and programs. The international technical assistance project “The Action Plan for the Shelter” is the most comprehensive of them.

Within the National Program, one shall ensure activities related to the development of the project for final closure of Chornobyl NPP Units No. 1, 2, 3, project for decommissioning of the cooling pond and design documentation for new radioactive waste management facilities required in the view of ChNPP decommissioning.

At present, the State Specialized Enterprise “Chornobyl Nuclear Power Plant” plans to transfer to the next decommissioning stage, namely the final closure. In 2014, the SNRIU performed the state review of nuclear and radiation safety of the design documentation “Final Closure of Chornobyl NPP Units No. 1, 2, 3” as a part of the project review.

There is an approved draft resolution of the Cabinet of Ministers of Ukraine “On Approval of the Construction Project “Final Closure of Chornobyl NPP Units No. 1, 2, 3”. The SNRIU considers the ChNPP statement and the set of documents for getting an individual written permit for taking activities at the stage of final closure of ChNPP Units No. 1, 2, 3.

 Infrastructure for Management of Chornobyl NPP Radioactive Waste

Implementation of the state strategy in management of radioactive waste shall be performed in accordance with the Strategy for Radioactive Waste Management in Ukraine, the National Targeted Environmental Program for Radioactive Waste Management, the National Program for Chornobyl NPP Decommissioning and Shelter Conversion into the Environmental Safety System. The strategy envisages creation and efficient functioning of the integrated system of radioactive waste management in Ukraine, which will ensure safer management (including disposal) of radioactive waste of all types and categories that was accumulated during the previous periods, is generated during the current use of nuclear energy and will be generated in the future. The strategy includes organizational and technical measures aimed at solution of issues related to the so-called Chornobyl origin waste confined in the Exclusion Zone and the territory of Chornobyl NPP. A range of new infrastructure facilities for safe management of radioactive waste is constructed in the Exclusion Zone of Chornobyl NPP and the Vektor site: retrieval of radioactive waste from existing temporary facilities for storage, sorting, processing and conditioning of radioactive waste, new facilities for waste storage, and near-surface facilities for disposal of conditioned radioactive waste.

The following facilities for management of ChNPP radioactive waste are constructed within ChNPP decommissioning: Liquid Radioactive Waste Treatment Plant (LRTP) and Industrial Complex for Solid Radioactive Waste Management (ICSRM). These facilities shall help to free the existing ChNPP facilities from accumulated radioactive waste, processing of radioactive waste to the state acceptable for disposal, and to perform safe disposal of waste packages in a near-surface facility and temporary storage of long-lived and high-level radioactive waste, which shall be disposed in a geological facility.

According to the “Integrated Program for Radioactive Waste Management on the Stage of Chornobyl NPP Decommissioning and Shelter Conversion into the Environmental Safety System”, it is planned to construct a range of additional facilities for radioactive waste management, including: a plant for production of radwaste packages and containers (almost completed); a site for storage, fragmentation and decontamination of dismantled equipment and other radioactive waste; a facility for preprocessing of liquid radwaste to remove transuranium and organic substances in order to ensure possible processing of liquid radwaste from the Shelter at LRTP; a complex for processing of radioactively contaminated metal, etc.

Liquid Radioactive Waste Treatment Plant (LRTP)

The project is implemented by donor funds of the EBRD Nuclear Safety Account.

Works on design completion of the plant for liquid radioactive waste reprocessing were resumed in 2007 pursuant to “Strategy for Completion of the Plant for Liquid Radioactive Waste Reprocessing” that was approved by Assembly of Donors of Nuclear Safety Account in EBRD. The completion of the design is carried out by Chornobyl NPP along with national enterprises.

Building and the main equipment of the Liquid Radioactive Waste Treatment Plant were constructed before 2006. However, the further analysis of the design, which was held in 2009 by OJSC Kyiv Institute “Energoprojekt”, revealed a set of design drawbacks, which required relevant changes and modifications in the design. There was determined a need for 22 modifications in the technical decision on making changes to LRTP design developed by Chornobyl NPP and approved by the SNRIU. On particular, modifications related to radiations safety, systems of radiation monitoring, screening, decontamination, ventilation, automated control, etc. Equipment for retrieval of liquid radwaste from existing facilities and their transfer to LRTP was found ineffective. It was agreed to use the available ChNPP system for liquid radwaste transport using compresses air.

Starting from 2006, while the facility is not completed, ChNPP performs operational maintenance of systems and equipment in order to keep LRTP building and equipment in an operable state.

On 28 March 2014, the SNRIU issued an individual permit OD No. 000040/7 for commissioning of LRTP. The experts performed nuclear and radiation safety review of the Final Report on LRTP Safety Analysis, Technical Specifications for Radioactive Waste Packages of Liquid Radioactive Waste Treatment Plant (200-l Barrel), Rev. 2” and a set of other operational documents.

Industrial Complex for Solid Radioactive Waste Management (ICSRM) consists of the following facilities:

  • Solid Radioactive Waste Retrieval Facility intended for retrieval of solid radioactive waste from the existing storage facility for solid radwaste of ChNPP;
  • Solid Radioactive Waste Processing Plant intended for sorting and processing (fragmentation, incineration, compaction, cementation) of solid radioactive waste of ChNPP;
  • Processed radioactive waste will be put and cemented in reinforced concrete 3 m3 containers to be sent for disposal. High-level and long-lived radioactive waste revealed during sorting will be placed in special metal barrels and sent for interim storage. Design capacity of the plant is intended for sorting and processing of 3500 m3 solid radioactive waste per year.

The Industrial Complex for Solid Radioactive Waste Management also includes the Interim Storage Facility for Low- and Intermediate-Level Long-Lived and High-Level Radioactive Waste intended for interim (during 30 years) storage of long-lived and high-level radioactive waste.

At present, the storage facility is ready for operation, but radioactive waste shall be accepted for storage in compartments after completed commissioning of SRTP.

The project is funded by the European Commission under TACIS program and contribution from the state budget of Ukraine.

Construction of all ICSRM facilities is completed and commissioning is ongoing.

Modernization of Long-Length Waste Cutting Facilities

Under TACIS project “Modernization of Long-Length Waste Cutting Facilities at ChNPP”, efforts are taken to create a facility, whose main purpose is to ensure cutting of log-length waste to be retrieved from reactor compartments during decommissioning of ChNPP-1,2,3 in accordance with the approved working design. The facility is planned to be mounted in Unit No. 2 and then to be moved to Units No. 1 and No. 3. The facility main function is to fragment (cut) components of the core, namely long-length components with expired life. The length of such components is from 6 to 22 m with a diameter of 145 mm, which requires special equipment and technologies for management in the decommissioning process.

In 2014, implementation of the project was suspended by the AMEC Company. The Plan for Licensing during Implementation of the Project “Modernization of Long-Length Waste Cutting Facilities…” is not performed. The further prospects in the project implementation and deadline for the facility commissioning will depend on the decision of the European Commission related to additional funds for the project termination.

There was started the review and research on creation of new additional facilities for radioactive waste management of ChNPP:

  • facility for purification of liquid radioactive waste of the Shelter from organic compounds and transuranium elements;
  • sites for storage, fragmentation and decontamination of dismantled structures and equipment;
  • facilities for clearance of dismantled materials from regulatory control.

In 2014, ChNPP developed the Feasibility Study for Creation and Location of New Additional Facilities for Management of Radioactive Material and Radioactive Waste and submitted it the regulatory authorities for review for further improvement of radwaste management system during ChNPP decommissioning.

New Safe Confinement of the Shelter

According to the National Program for Chornobyl NPP Decommissioning and Shelter Conversion into the Environmental Safety System approved by the Law of Ukraine No. 886-VI dated 15 January 2009, measures taken in the Shelter are qualified as its conversion into the environmental safety system. The task on conversion of this facility is solved by sequential development and implementation of certain plans, projects and programs. The international technical assistance project the Action Plan for the Shelter is the most comprehensive among them

The main purpose of the Action Plan for the Shelter is the creation of the New Safe Confinement of the Shelter (NSC).

The confinement is a protective building with a set of process equipment for removal of materials from the destroyed ChNPP-4, which include nuclear fuel, radioactive waste management and other systems, and is intended to perform activities on conversion of this power unit into the environmental safety system and ensuring safety of personnel, the public and environment.

The confinement is an arch building with 100 years operation lifetime. The confinement construction consists of two startup complexes:

  • SC-1 NSC is a protective structure with process support systems and required infrastructure;
  • SC-2 NSC includes an infrastructure for dismantling of unstable structure of the Shelter.

At present, SC-1 NSC is under implementation, and design decisions are developed for SC-2 NSC. French company (common venture) Novarka is the engineering contractor. The company includes VINCI Construction Grands Projects and Bouygues Travaux Publics. Other international companies and Ukrainian design, scientific and building organizations can be involved as subcontractors.

Novarka implemented SC-1 NSC through separate projects developed in 6 license packages (LP). Preparatory activities within license packages LP1-LP4 are completed. Some efforts under LP-4, namely dismantling of the ventilation pipe VT-2, was excluded from the scope of Novarka activities and was performed by the Ukrtransbud Corporation.

According to the documents approved by the SNRIU for ChNPP, from 31 March to 2 April 2014, the eastern part of NSC has been moved into the so-called expectation area. In the end of November 2014, the NSC eastern arch was moved back to its western part.

On 15 May 2014, the Verkhovna Rada of Ukraine ratified the Agreement on Increased Contribution to the Chornobyl Shelter Fund. Ukraine confirmed its readiness to make an additional contribution to the Chornobyl Shelter Fund in the amount of 63.4 million USD.

The long-expected movement of the New Safe Confinement over the Shelter and Chornobyl NPP Unit 4 damaged after the accident was completed on 29 November 2016.

Vektor Complex

The Vektor site is located in the Exclusion Zone at a distance of 17 km north-west from the Chornobyl NPP. The Vektor complex is a set of plants on decontamination, transport, processing and disposal of radioactive waste. The construction of the complex started in 1998 and is performed in two stages.

Vektor Stage 1 is intended for disposal of radioactive waste generated from the ChNPP accident. The Stage I startup complex includes the facility for disposal of radioactive waste in reinforced concrete containers (SRW-1) and module facility for disposal of radioactive waste in bulk (SRW-2) and the required infrastructure facilities. The operator (State Specialized Enterprise on Management of Exclusion Zone Major Construction) at the stages of siting, design and construction of Vektor radwaste disposal facilities completes construction activities in SRW-1, SRW-2 and equips the infrastructure facilities, including car wash, radiological laboratory, changing room.

The Engineered Near-Surface Disposal Facility for Solid Radioactive Waste has been constructed and commissioned at the Vektor site. ENSDF with a capacity of 55 000 m3 is intended for disposal of conditioned radioactive waste of ChNPP. For the period while plants for ChNPP radwaste processing do not produce conditioned radwaste packages, measures are taken to keep systems and equipment of the disposal facility in an operable state.

According to the feasibility study for Vektor Stage 2 approved by the Resolution of the Cabinet of Ministers of Ukraine, Vektor Stage 2 envisages construction of a set of facilities for radioactive waste management:

  • centralized near-surface disposal facilities for radioactive waste generated during operation of Ukrainian NPPs and accumulated on sites of state specialized plants for radwaste management of UkrDO Radon;
  • facilities for management of radioactive waste from ChNPP and sites of UkrDO Radon plants;
  • facilities for long-term storage of high-level and long-lived radioactive waste, including facilities for long-term storage of vitrified radioactive waste to be returned from the Russian Federation after treatment of spent nuclear fuel from Ukrainian NPPs;
  • centralized facility for long-term storage of disused high-level radiation sources.

The Vektor site operates the Engineered Near-Surface Disposal Facility for Solid Radioactive Waste with a capacity of 50 210 m3 intended for disposal of packages with radwaste of Chornobyl NPP. The disposal facility consists of two parallel sections, each having 11 reinforced concrete compartments (modules). The disposal facility is equipped by the central drainage gallery, two mobile frame structures with bridge cranes for filling of modules, the system for radiation monitoring and control of the environment. Putting of radwaste packages from the plant for liquid radioactive waste management of ChNPP into ENSDF was started in 26 April 2014.

The Department of Energy and Climate Changes of the Great Britain actively supports construction of the Centralized Long-Term Storage Facility for Radiation Sources (CLTSF). The facility currently has no analogues in the world and is a key element in improvement of all the system for management of disused radiation sources in Ukraine. It shall ensure centralized storage of more than 500000 disused radiation sources of different types and structures, which today are accumulated on sites of the specialized radioactive waste management plants of UkrDO Radon, and after their use in medicine, science and industry.

 References:

  1. SNRIU Material