The production of electricity at nuclear power plants is accompanied by the generation of radioactive waste with different activities and aggregate states in the main technological process and maintenance operations. Radwaste accumulation causes additional risks for the public and the environment and is one of the main negative factors in the public’s perception of nuclear power.
Processing of plant radwaste to obtain a product suitable for transport and long-term safe storage or disposal demonstrates the nuclear operator’s commitment to the fundamental safety principle of radwaste management without leaving undue burden on future generations and is a prerequisite for sustainable and safe development of nuclear energy in the country.
Uatom.org Editorial Board communicated with experts of the operating organization, regulatory body and public organizations to learn about the establishment history of the pilot radwaste processing plant (RWPP) at Rivne NPP, Energoatom’s future plans related to the management of radwaste accumulated at NPPs, as well as radiation and environmental safety issues related to this activity.
RWPP equipment testing (Photo: Rivne NPP Press Service)
RWPP AT RIVNE NPP SITE IS ENERGOATOM’S PILOT PROJECT
The Rivne NPP design envisaged a solid radwaste processing plant to reduce the volume of radwaste generated during plant operation. It was planned to construct and commission this plant together with RNPP Unit 4.
The construction of RNPP Unit 4 and the radwaste processing plant building was suspended because of the moratorium on the construction of new NPPs on the territory of Ukraine after the Chornobyl accident and was renewed only at the beginning of the new century.
RNPP Unit 4 was commissioned in 2004. The construction project for the RNPP radwaste processing plant was started in 2005 under the TACIS international technical assistance project with support of the European Commission (EC) due to the operator’s limited resources and the lack of manufacturers of radioactive waste processing plants in Ukraine.
RWPP building at RNPP site (Photo: Rivne NPP Press Service)
According to Volodymyr Horbunov, Head of Radwaste Management Sector in Radwaste Decontamination Department at Rivne NPP, the process equipment and radwaste processing operations were selected considering international experience and IAEA and EU recommendations. The process line of the RNPP radwaste processing plant includes seven facilities. Four facilities for retrieval (ONET, France), sorting and fragmentation of solid radwaste (Nukem, Germany), supercompaction (Nukem, Germany) and activity measurement (Envinet, Czech Republic) were supplied under TACIS project financed by EU. Three additional facilities for sorting (Envitek, Ukraine), oil cleaning (KTZ-ENERGOMASH, Ukraine) and metal decontamination (Spetsenergetikos Consortium, Lithuania-Ukraine) were constructed for Energoatom’s costs.
“The project for radioactive waste processing at RNPP site has passed all necessary reviews including those with involvement of international experts on safety assessment,” Volodymyr Horbunov noted. “Industrial operation of the plant facilities will decrease the volume of solid low-level radwaste by several times. This concerns radwaste being generated now during plant operation, radwaste that has already been accumulated and is placed in the storage facilities, and future radwaste streams to be generated in RNPP decommissioning”.
Sorting facility manipulators (Photo: Rivne NPP Press Service)
Owing to the implementation of innovative radwaste processing technologies, the radioactive waste management system at RNPP site will reach a new modern level complying with international standards and will contribute to NPP operational safety by reducing exposure risks to personnel and the environment. After reaching the design power, the plant will be capable of processing up to 4.5 m3 of radwaste per day.
After receiving the Certificate of the State Architectural and Construction Inspectorate of Ukraine, IU Series No. 163180820543, on compliance of the completed RWPP, Rivne NPP submitted an application and obtained a permit of the State Nuclear Regulatory Inspectorate of Ukraine for commissioning of the new infrastructure installation. The comprehensive program for testing of facilities and equipment including “hot tests” using real radioactive waste was implemented under this individual permit. A report based on the testing results was submitted to SNRIU.
In RWPP industrial operation, the processed products in the form of containers with specified characteristics will be accumulated in a specially equipped radioactive waste storage facility at RNPP. Solid radwaste packages will be further transported for storage or disposal to specially equipped storage facilities on the Vektor site in the exclusion zone.
Control of supercompaction facility (Photo: Rivne NPP Press Service)
According to Liudmyla Blyzniukova, Director of Energoatom’s Department for Radioactive Waste Management and Radiation Safety, the operator currently implements a systematic approach to solving radioactive waste management issues through:
– improving the management system and organizational structure for radwaste handling in the operating organization and its separated entities;
– implementing new radwaste management technologies;
– maintaining the radwaste accounting and control system;
– improving the radwaste processing and minimization system;
– scientific and technical support in radwaste management;
– funding the measures for the commissioning of radwaste processing plants.
The Energoatom policy in this area, according to the approved National Radwaste Management Strategy, is based on the construction of radwaste processing plants at each NPP that will allow waste to be treated for transfer into the state property for long-term storage and disposal, significant decrease of radwaste amounts at NPP sites, rational use of design-basis radwaste storage facilities, reduction of dose loads on personnel and safety culture improvement.
Trial operation of the radwaste processing plants constructed at Rivne and Zaporizhzhya NPPs with international technical assistance under the TACIS program was started in December 2017.
Considering that the radioactive waste processing plants include high-tech sophisticated equipment, the first stage of trial operation was performed with radiation-free materials such as dummy radioactive waste. After successful tests, the hot test stage is further conducted with real radwaste.
In 2019, the radwaste processing plants at ZNPP and RNPP in commercial operation will process both accumulated radwaste and radioactive waste generated in current NPP operation according to the design characteristics.
Trial operation of the radwaste processing plant at Khmelnitsky NPP site is planned for 2021. Tendering for supply of the main process equipment is underway.
Trial operation of the radwaste processing plant at South Ukraine NPP is planned for 2023. The design documentation is currently under revision to be in line with new regulations, financial indicators, etc. The equipment will be purchased and construction and installation activities will be started in full scope after the approval of the project.
The construction of KhNPP and SUNPP RWPPs is funded by Energoatom.
RWPP is an important component of the entire radwaste management cycle: from waste generation to waste disposal in compliance with current safety requirements and IAEA recommendations on radwaste management.
NUCLEAR REGULATOR’S VIEWPOINT
“NPP designs of the second generation did not envisage process radwaste processing plants, they included only storage facilities for waste accumulation and storage in bulk, without sorting according to physical and chemical characteristics”, Tetiana Kutuzova, Head of Emergency Preparedness and Radiation Protection Department of SNRIU Nuclear Installation Safety Directorate, noted. “The requirement for minimizing radwaste in places of its generation was included in the licensing of operating NPPs; thus, the operator ensures subsequent performance of this licensing condition”.
New NPP designs implemented in different countries include comprehensive lines for radwaste processing into the form suitable for final disposal with detailed characterization of radwaste packages.
Sufficient free capacities in design-basis radwaste storage facilities are among the conditions for the safe operation of nuclear power plants. The Energoatom plans for NPP long-term operation and requirements for NPP safety and safe radwaste management (together with the principle that undue burden of radioactive waste management should not be placed on future generations) became an incentive to construct radwaste processing plants at operating NPPs. Ideally, NPPs should process all radwaste accumulated at the sites before completion of the operational stage. Such examples are demonstrated at NPPs in Slovak and Czech Republic that operate similar types of VVER reactors, and for which the processing and disposal of accumulated radwaste were among the obligatory conditions to continue the operation of such units after the countries joined the EU.
Radioactive waste is processed at the sites of operating Ukrainian NPPs under the licenses for NPP operation. However, the introduction of technologies such as incineration, supercompaction, fragmentation and cementation of radioactive waste required special training of personnel to perform such production processes, the development of additional radiation monitoring systems at the facilities and their integration into the radiation monitoring systems at NPP site, and changes in the existing approaches to radioactive waste characterization, since not only activity is important for safety justification of the radioactive waste disposal system in transfer and transport, but also detailed radionuclide composition and physical characteristics of the mobilizing matrix for calculation of its confining properties.
For NPP personnel and management, the RWPP construction projects became an additional challenge, since they required additional resources and efforts to establish technological processes that were fundamentally different from the electricity production. Understanding the need for this work by RNPP and Energoatom top management became an additional driving force for achieving a practical result such as NPP operation and production of the first radioactive waste packages ready for transfer for disposal in 2018.
Before issuing a separate license for commissioning the new infrastructure installation RWPP, SNRIU conducted a comprehensive survey at RNPP in order to verify the operator’s capability to ensure safety of new technological processes. All testing programs and safety justification documents have passed regulatory review.
“We follow the RNPP success in this important activity for the safety of the public and the environment, and we want to operate the radioactive waste processing systems on a systematic basis in accordance with the design and established goals. For this purpose, Energoatom should ensure proper and sustainable funding of radwaste processing (not according to the “residual principle”), motivation of trained personnel, timely maintenance of equipment and, of course, safety of all production processes”, Tetiana Kutuzova commented.
Failure of the Centralized Radioactive Waste Management Enterprise of Radon Association to accept radwaste from NPPs to the Vektor site in the exclusion zone causes the risk that the processing products will be stored at NPP sites, although Energoatom completely fulfills its obligations related to payments to the State Radwaste Management Fund. The cooperation between the operators – radwaste producer and specialized enterprise that should accept waste into state ownership for disposal – should be strengthened on a systematic basis in order to avoid this risk. “The efficiency of using the costs of the State Radwaste Management Fund requires appropriate analysis and public control to ensure that the resources invested in the construction of these storage facilities really work for achieving the public safety objectives”, the expert believes.
According to Olha Liashchuk, a representative of the Public Ecological Organization “Rivne Ecoclub”, the construction of radioactive waste processing plants at NPP sites is only a temporary solution because the issue of long-term radioactive waste storage remains unsolved in Ukraine. “A positive result from the construction of this plant at RNPP is decrease in the amount of accumulated radioactive waste at the site. However, failure to solve the issue of long-term disposal of radioactive waste and systematic generation of new waste actually cause the risk of leaving undue burden on future Ukrainian generations”, the expert noted.
Serhii Denysenko, a representative of the All-Ukrainian Ecological Public Organization “MAMA-86” noted that radioactive waste processing was a very important part of the NPP production cycle. After all, waste becomes more compact and safe and prepared for long-term storage in protected storage facilities. At the same time, the risks of processing would hardly exceed the risks of storing unprocessed waste. That is, we are talking about specific decrease in burden on the environment and increase in radiation safety.
“Thus, radioactive waste reprocessing starts at Ukrainian nuclear power plants with a delay for several decades, at the end of the life cycle of operating NPPs, in 2018. Despite the delay, this is undoubtedly a positive factor, especially considering the co-financing and monitoring by relevant European structures. At the same time, the All-Ukrainian Ecological Public Organization “MAMA-86” continues defending the vision of future Ukrainian energy in other forms that are more safe than nuclear and thermal power”, Serhii Denysenko pointed out.
Uatom.org Editorial Board