Assessment of the Impact of Organic Matter Discharge from a Nuclear Power Plant with a Recirculating Cooling Water System

Abstract

Nuclear power plants (NPPs) use large amounts of water for cooling, recirculating cooling water systems (RCWS) take water and discharge it to the environment, concentrate natural constituents and introduce chemicals used to maintain the chemistry of the NPP. Changes in organic matter (OM) content can be caused by natural processes as well as human activities. Natural OM content shows seasonal patterns, high OM loads can lead to microbial blooms which further affect water quality. The subject of the research is OM discharges with return water from RCWS NPPs. The research was carried out using the example of the RCWS Rivne NPP and the water of the Styr River, from which the Rivne NPP uses water. The purpose of the research is to study OM discharges, and to conduct an environmental assessment of the impact on the surface water of the Styr River on the water discharges of the Rivne NPP. The relevance of the research lies in the assessment of the nonradiative environmental impact of the NPP, with the establishment of a correlation between the OM content and the technological modes of operation of the Rivne NPP. The novelty of the research is the multicomponent evaluation of the OM content by various indicators of TOC, COD and BOD5 control and determination of the dynamics of their changes with the establishment of variability factors. The practical value of the study lies in the possibility of applying the methods to other power plants using RCWS.

A numerical study of the surface water using levels of the organic pollution indexes: comparative characteristics and educational opportunities

“…Moreover, the different interpretations of the OPI levels obtained by the different methods of this study include the interpretation of results from 'none' for (3, 4) to 'pure' for (1,2). Students can acquire a systematic approach to the environmental assessment of pollution and avoid ambiguity in the interpretation of results 17 . Since environmental safety is based on the concept of environmental risk, which is an assessment of environmental hazards, the strategy for ensuring environmental safety should also include the prevention of environmental risks 18 .…”

Behaviour of dissolved inorganic salts in the cooling water of a nuclear power plant open recirculation system and formation of water discharge

“…Heat removal from ORS requires the evaporation of make-up water, and the concentration of DIS in the cooling water increases over time [11], which is defined as the cycle of concentration (COC) [12]. According to [13,14], evaporation processes in ORS occur more intensively with increasing temperature, and the relative value of W (1.2) is almost constant for the designed type of cooling tower. With an increase in BD and MU consumption, a greater water exchange is achieved for ORS (1.1) and (1.2), resulting in a decrease in the COC [15].…”