Swiss Review 6/2019

Swiss Review / November 2019 / No.6 18 Economy THEODORA PETER At exactly 12.30 p.m. on 20 December, some 20 kilometres west of Berne, the on-duty technicians in the control roomof theMühleberg nuclear power plant will press two buttons. Control rods will be in- serted into the reactor and the nuclear chain reaction stopped. After 47 years in operation, Mühleberg – the second oldest of Switzerland’s four nuclear power stations – will then be off the grid for good. This will not yet allay the risk of a nuclear accident, but within three days of the switch-off the temperature and pressure inside the reactor will have dropped to such an extent as to preclude an explo- sion. Nevertheless, a devastatingmeltdownwill theoretically still be possible. Independently operated, earthquake-proof cooling systems are designed to prevent this from occurring. The 15-year process of decommissioning will begin on 6 January 2020. First, the highly radioactive fuel elements will be moved from the reactor to the adjacent storage pool, where theywill stay for a few years to cool down before being transported bit by bit to the interim storage facility for radioactive waste in Würenlingen (canton of Aar- gau). This will be done by 2024. However, Mühleberg will not be com- pletely free of radiation until 2031. Before then the parts of the plant with a low level of radioactivity will also have to be removed in addi- tion to building debris. The decommissioning should then be fully completed by 2034. Whether this piece of the land by the River Aare is returned to green meadow remains to be seen. Low electricity prices make nuclear energy uneconomical It was for economic reasons that the Bernese energy group BKW de- cided in autumn 2013 to shut down the Mühleberg nuclear power plant. Low prices on the electricity market and the high cost of nec- essary upgrades meant that continuing with the plant simply made no sense. Building a new reactor was no longer an option either, with the Federal Council having introduced amoratoriumon newnuclear plants and approved the transition towards renewable energy follow- ing the 2011 Fukushima reactor disaster. News that nuclear power would be phased out came as a shock for the 300 or so workers at Mühleberg. Yet most of these staff remained on board and are now giving the last rites to a technology that they used to regard as having a future. BKW is entering uncharted territory in this, the first-ever decom- missioning of a Swiss power reactor. By moving quickly to acquire a number of German companies specialised in nuclear technology and radiation protection, it has equipped itself with the necessary exper- Decommissioning Mühleberg At the end of 2019, Mühleberg will become the first-ever Swiss nuclear power plant to be switched off permanently. The pioneering work of decommissioning the plant will take around 15 years. The question remains of where the high-level radioactive waste can be securely stored for tens of thousands of years. High-level radioactive-waste containers at the Würenlingen interim storage facility – with survey meters in the foreground. Photo: Keystone tise. The group hopes to gain valuable experience from dismantling Mühleberg, because the decommissioning of nuclear power plants could well gain traction abroad. Germany intends to phase out nu- clear power completely by 2022, while plant closures are also on the agenda in other European countries. Waste remains hazardous for hundreds of thousands of years It will cost 927 million francs for BKW to decommission Mühleberg. Added to this is over 1.4 billion francs for the interim and subsequent final storage of radioactive waste. However, it will be decades before an appropriate deep repository is built. Until then, high-level waste from all Swiss nuclear power plants will be stored at the Würenlin- gen interimstorage facility in steel containersweighing up to 140met- ric tons. Each of these vessels will contain almost 20 metric tons of highly radioactivematerial that will remain hazardous for hundreds of thousands of years unless new ways are found to significantly re- duce the radioactive decay time. For almost half a century, the National Cooperative for the Dis- posal of Radioactive Waste (Nagra) has been looking for a suitable site to build a final repository deep below ground. According to the Nuclear Energy Act, disposal in deep geological repositories is the only way to protect humans and the environment from radioactive contamination in the long term. Three potential locations are cur- rently in the running: Jura Ost in Bözberg in the canton of Aargau, Nördlich Lägern in the cantons of Aarau and Zurich, and Zürich Nor-