ydinjäämistöä

ydinjäämistöä, meaning "nuclear waste" in Finnish, refers to spent nuclear fuel and other radioactive waste materials generated from nuclear power plants and other nuclear facilities. This waste is highly radioactive and remains so for thousands of years, requiring careful management and long-term storage to prevent harm to human health and the environment.

The process of generating ydinjäämistöä begins with the use of nuclear fuel, typically uranium, in nuclear reactors. After a period of operation, the fuel becomes spent and is removed from the reactor. This spent fuel is initially stored in cooling pools at the power plant to allow short-lived isotopes to decay and reduce heat generation.

Following the cooling period, spent fuel can be reprocessed to recover usable materials or be directly disposed of as high-level waste. Reprocessing can separate plutonium and uranium, which can be reused as fuel, but it also creates other radioactive waste streams. Direct disposal involves placing the spent fuel in secure repositories.

Low-level and intermediate-level radioactive waste also contribute to ydinjäämistöä. These materials, such as contaminated tools, clothing, and equipment, are less radioactive than spent fuel but still require specialized handling and disposal. Their management typically involves containment and storage in designated facilities.

Finland has been actively developing solutions for ydinjäämistöä. The country is constructing an underground final repository called Onkalo, designed to permanently store spent nuclear fuel deep within Finnish bedrock. This approach aims to isolate the waste from the biosphere for the extremely long periods necessary for its radioactivity to diminish to safe levels. The safe management of ydinjäämistöä is a significant challenge, involving complex technical, environmental, and societal considerations.