But contrary to other commodity markets, in the case of a disturbance in supplies, nuclear reactors operate without refuelling for 12 to 18 months (thus securing months of electricity supply before halting), and if delivery of fresh fuel is delayed, a reactor can still be operated for two to six months beyond its scheduled shut down, at gradually lower power, whereas strategic oil stocks correspond in most EU countries to 90 days’ forward requirements. Thus shortages due to geopolitical or economic factors are far less harmful in the nuclear fuel market rather than in other commodity markets. In 2008, the EU-27’s gross inland consumption consisted of 36.4% of oil, 25.1% of natural gas, 13% of nuclear energy and 12% of coal, for the most-used energy sources.