The Paks nuclear plant said that traces of radioactive gas had leaked into the atmosphere earlier this month but the incident, the most serious at the Hungarian plant to date, posed no environmental danger. The incident, originally classified level two on the International Atomic Energy Agency’s seven-step scale, was later raised to level three. This is the highest incident level, as events from four on the scale are considered accidents. Paks has four Soviet-type VVER-440 pressurised water reactors, the first of which became operational in 1982. Reactor II has not resumed operation yet. Every idle day means a revenue loss of 50 million forints ($223,000), the plant added. Reactor II started to leak traces of radioactive gas on April 10, during a cleaning of the fuel rods. Upon opening the reactor bloc last week, Paks raised the level of the incident to three but said the incident did not affect the installations or technological systems of reactor bloc II and emission levels remained within accepted levels. During the incident, 30 fuel rods in Reactor II were seriously damaged and had to be placed into a pool containing several hundred cubic metres of water for cooling. The four reactors of Paks with a capacity of 1,860 megawatts cover about 40 percent of Hungary’s annual power consumption.