<P> High - level waste (HLW) is produced by nuclear reactors . The exact definition of HLW differs internationally . After a nuclear fuel rod serves one fuel cycle and is removed from the core, it is considered HLW . Fuel rods contain fission products and transuranic elements generated in the reactor core . Spent fuel is highly radioactive and often hot . HLW accounts for over 95 percent of the total radioactivity produced in the process of nuclear electricity generation . The amount of HLW worldwide is currently increasing by about 12,000 metric tons every year, which is the equivalent to about 100 double - decker buses or a two - story structure with a footprint the size of a basketball court . A 1000 - MW nuclear power plant produces about 27 tonnes of spent nuclear fuel (unreprocessed) every year . In 2010, there was very roughly estimated to be stored some 250,000 tons of nuclear HLW, that does not include amounts that have escaped into the environment from accidents or tests . Japan estimated to hold 17,000 tons of HLW in storage in 2015 . HLW have been shipped to other countries to be stored or reprocessed, and in some cases, shipped back as active fuel . </P> <P> The radioactive waste from spent fuel rods consist primarily of cesium - 137 and strontium - 90, but it may also include plutonium, which can be considered a transuranic waste . The half - lives of these radioactive elements can differ quite extremely . Some elements, such as cesium - 137 and strontium - 90 have half - lives of approximately 30 years . Meanwhile, plutonium has a half - life of that can stretch to as long as 24,000 years . </P> <P> The ongoing controversy over high - level radioactive waste disposal is a major constraint on the nuclear power's global expansion . Most scientists agree that the main proposed long - term solution is deep geological burial, either in a mine or a deep borehole . However, almost six decades after commercial nuclear energy began, no government has succeeded in opening such a repository for civilian high - level nuclear waste, although Finland is in the advanced stage of the construction of such facility, the Onkalo spent nuclear fuel repository . Reprocessing or recycling spent nuclear fuel options already available or under active development still generate waste and so are not a total solution, but can reduce the sheer quantity of waste, and there are many such active programs worldwide . Deep geological burial remains the only responsible way to deal with high - level nuclear waste . The Morris Operation is currently the only de facto high - level radioactive waste storage site in the United States . </P> <Table> <Tr> <Td> </Td> <Td> The examples and perspective in this article deal primarily with the United States and do not represent a worldwide view of the subject . You may improve this article, discuss the issue on the talk page, or create a new article, as appropriate . (November 2013) (Learn how and when to remove this template message) </Td> </Tr> </Table>

Which type of storage facility is assumed to be safe for long-term storage of nuclear waste products
find me the text answering this question