owner. Publicly available reports on matters such as trans- portation and final disposal of spent nuclear fuel were also utilized in the assessment.
Legislation regulating the waste management and the quantity, type, and processing methods of the waste generated are described in more detail in Sections 3.11, 3.12, and 3.13.
7.11.2 Construction phase impacts
In the construction phase, management of conventional waste will be arranged in accordance with the environ- mental guidelines so that the impacts of the waste and its treatment on the environment are minimized. The primary objective is to reduce the amount of waste generated. The secondary option is to utilize waste in new applications and in the production of materials or energy. The last option is to appropriately dispose of the waste in a landfill site.
Waste management in the construction phase is based on efficient sorting of waste at the site of its generation as well as on uniform and efficient instruction of the various parties and companies operating at the site on appropri- ate waste management procedures. Waste generated during construction will be appropriately sorted and recycled or utilized in energy production as far as possible. The earth-moving, excavation, and dredging masses generated during the construction phase will be utilized, as far as pos- sible, in various on-site filling and leveling operations. The handling, storage, and transportation of hazardous waste will be arranged in accordance with the regulations.
The impacts of waste water generated at the construction site and its processing are discussed in Section 7.4.3.
No radioactive waste will be generated during the con- struction phase.
7.11.3 Operation phase impacts
7.11.3.1 Conventional waste
Conventional waste generated at the nuclear power plant will include iron and sheet metal scrap, wood, paper, and cardboard waste, as well as biowaste and energy waste. Most of the waste generated can be utilized through recycling or use in energy production. Sorted waste will be delivered for treatment, utilization, and final disposal in accordance with the requirements of waste legislation and environmental permit decisions.
Waste management at the plant will not cause any environmental impacts. The amount of waste generated will be kept as small as possible, and the waste to be uti- lized as large as possible. The fulfillment of the targets will be monitored by keeping records of the amounts of sorted waste fractions and utilization of the waste frac- tions. For example, paper and cardboard, metal, wood, biowaste, glass, and energy waste will be separated from municipal waste. Solid matter carried to the nuclear power plant along with the cooling water, such as algae, refuse, and fish, will be removed using screens and filters, dried, and baled. Then it will be delivered for processing according to its type.
7.11.3.1 Hazardous waste
Non-radioactive hazardous waste generated at the nuclear power plant will be processed in accordance with the requirements of waste legislation and environmental per- mit decisions in the same manner as at other industrial plants. Hazardous waste generated at the nuclear power plant will include batteries, fluorescent tubes, light bulbs, oil-contaminated filters, waste oil, solvent and chemical waste, and waste electric and electronic equipment.
Hazardous waste will be stored in appropriately labeled, covered, and water-tight vessels or containers. Differ- ent types of hazardous waste will be kept separate from one another. The release of hazardous waste into the soil, groundwater, or surface water and sewers will be prevented.
Hazardous waste will be delivered to a hazardous waste treatment plant, and the delivery will be recorded in the transfer document in which the required information on the waste fractions will be entered. The amount of hazard- ous waste generated will mainly depend on the extent of the outage operations. Hazardous waste will not cause any impacts on the environment due to its small quantity and the appropriate processing methods utilized.
7.11.3.3 Operating waste
During the operation of the nuclear power plant, operating waste will be generated in operations such as processing of radioactive liquids and gases and maintenance and repair work performed in controlled areas. Operating waste include protective clothing, insulation materials and cleaning mate- rials. Liquid operating waste includes radioactive concen- trates and masses generated as a result of the plant’s water treatment processes. Operating waste will be classified as low or intermediate level waste on the basis its radioactivity. Fur- thermore, legislation allows the separation of the fraction of very low level waste from other low level waste and the final disposal of this lowest level waste in a surface repository.
An estimate of the volumes of operating waste generated in the nuclear power plant is presented in Section 3.12 (Table 3-5). The estimated volume of solid waste generated over the entire operation phase of the plant (after treatment and pack- ing) is approximately 2,500 m3, while the estimated volume
of liquid waste is approximately 2,100 m3. An effort will be
made to minimize the generation of operating waste through careful planning and implementation of maintenance oper- ations, choosing the right work methods, efficient sorting of waste, and favoring re-usable tools as far as possible.
Operating waste will be collected and removed from the plant premises without delay. For storage or final disposal, waste will be packed in vessels (typically, 200-liter drums) which facilitate the transfer of the waste, prevent the dispersion of radioactive substances, and reduce the risk of fire. Low level waste packages can be handled without any radiation shield- ing. The handling and transportation of intermediate level waste require the use of radiation shielding, and the packages often function as technical release barriers in the final disposal.
A more detailed description of the treatment and man- agement of operating waste is presented in Section 3.12.
196 7 Assessment methods, the present state of the environment and the assessed environmental impacts
Adequate facilities will be built at the nuclear power plant for the treatment and storage of operating waste. The facilities will contain systems enabling the safe handling and transportation of waste and the monitoring of the quantities and types of radioactive substances. Prior to final disposal, packed waste will be stored under supervision in a storage building located immediately adjacent to the solid waste treatment facilities in the plant site. According to the plan, enough storage capacity for 10 years will be built for operating waste. The principle behind the final disposal of operating waste is to isolate the radioactive substances con- tained in the waste from the environment so that the safety of the environment is not endangered at any stage.
Two different techniques can be applied for the final dis- posal of operating waste; surface repository or underground repository. Presented below is an assessment of the environ- mental impacts of both alternatives. A more detailed descrip- tion of the repositories and operating waste treatment and management methods is presented in Section 3.12.
Underground repository
The underground repository for operating waste will be designed in accordance with the requirements of Govern- ment Decree (736/2008). The Decree states that the maximum limit of the annual dose to any individual of the population from the operation of the nuclear power plant as a whole, including the operation of the final disposal repository, at any given time is 0.1 mSv. The annual dose to any individual in the population from possible accidents caused by natural phenomena or human activity will remain below 5 mSv.
Furthermore, the repository will be designed so that the annual dose to any individual from accidents with expected frequencies of occurrence higher than once in a thousand years will remain below 1 mSv. The average annual radiation dose of Finnish people from background radiation is 3.7 mSv (STUK 2011c). The design objective set for any repos- itory constructed in bedrock will be that the annual radi- ation dose to individuals may only exceed 0.01 mSv in the case of a limited critical group, i.e. the plant’s workers.
The emissions of radioactive substances from the under- ground repository into the atmosphere will normally be insig- nificant. The impacts of accidents are described in Section 7.13.
The waste packages transported into the repository must be undamaged and in good condition, and there must not be any loose contamination on their surface. Thus, no radioactive substances will be released from the waste packages during the operation phase, and the water accumulating in the repos- itory cannot be contaminated by radioactive substances.
After the sealing of the repository, flows caused by tem- perature differences (convection) or the shifting of mole- cules from regions of higher concentration to regions of lower concentration (diffusion) will, over long periods, carry small quantities of radionuclides contained in the waste into the environment. Technical and natural release barriers will prevent and slow down the migration of radio- nuclides. The release barriers utilized in final disposal will be designed to effectively prevent the release of radioactive substances for at least hundreds of years in the case of short- lived waste or thousands of years in the case of long-lived
waste. After this time, the radioactivity inside the repository will have decreased to an insignificant level.
No factors unfavorable to long-term safety (Government Decree 736/2008) must be present at the final disposal repos- itory. Such factors include groundwater resources of local sig- nificance, the utilization or quality of which the construction of a final disposal facility for operating waste would endanger. There are no classified groundwater catchment areas within the area affected by the planned construction of a final disposal facility at the power plant site. The nearest classified ground- water catchment area is located some 10 kilometers from the future location of the power plant. The groundwater resources of the surrounding areas will not be contaminated with radio- active substances due to the final disposal of operating waste.
Surface repository
In the case that a repository located on or immediately below the ground surface is constructed at the power plant site, it will only be used for the final disposal of very low level waste in accordance with Section 22 Government Decree (736/2008). The total volume of waste disposed of in the surface repository will be kept at such a level that the activity of radioactive substances falls below the limit values set for large-scale final disposal in Section 5, subsection 1 of the Nuclear Energy Decree.
The radioactivity concentration of the very low level waste disposed of in this repository will be so low that the waste packages to be disposed of can be handled without implementing any special radiation protection arrangements.
As the total radioactivity of the waste to be disposed of will be low and the waste will be packed tightly and isolated from the environment by covering it with a compact sealing layer, no radioactivity will be released into the atmosphere or migrate into the soil. Technical and natural release barriers will also prevent and slow down the migration of radionu- clides. No waste containing radioactivity bound to readily volatile or dust-forming substances will be disposed of in the repository.
Emissions could only take place in the case of a fire, and even then, the impacts of radiation would remain insignificant due to the low activity level of the waste. The possibility of fires will be taken into account by ensuring the availability of firefighting equipment in the vicinity of the repository during deposit campaigns. The possibility of a fire will also be taken into account during the sorting and packing of waste.
The filling of the repository for very low level waste with water will not be possible because the repository will be located on the ground surface and because flooding will have been taken into account in its design. The base slab of the repository will isolate the waste from the soil, and any seepage water permeating the surface layers covering the repository will be collected and analyzed in order to deter- mine the concentrations of radioactive substances. If nec- essary, the seepage water can be cleaned in an appropriate manner at the power plant’s liquid waste treatment plant before it is released into the water system. This will guaran- tee that no significant quantities of radioactive substances are released from the repository.
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