president Masataka Shimizu resigns after reporting the largest financial losses in the company's history. Sunday, 22 May TEPCO reports that reactor 3 leaked at least 250 tons of radioactive water into the Pacific Ocean over a period of 41 hours beginning on 10 May 2011. Tuesday, 24 May On the eve of the arrival in Tokyo of a delegation from the International Atomic Energy Agency, TEPCO admits that the cores of reactor 2 and reactor 3 also melted down in the days immediately following the earthquake in mid-March 2011. 16 hours after the earthquake and SCRAM, the fuel rods of reactor 1 had "mostly melted and fallen into a lump at the bottom of the pressure vessel – a state that TEPCO officials have described as a 'meltdown'". A TEPCO spokesman Yoshimi Hitosugi stated last night, "The situation inside two and three is almost the same." TEPCO further stated that the fuel in reactor three took about 60 hours to melt and that the reactor melted down 100 hours after the magnitude nine quake struck. Wednesday, 25 May TEPCO informs the Nuclear and Industrial Safety Agency and the government of Fukushima Prefecture of the results of soil tests for plutonium (, and ) carried out around the Fukushima Daiichi plant. While the levels were comparable to the fallout in Japan from atmospheric nuclear testing, TEPCO deemed that the plutonium had originated from the accidents. Saturday, 28 May TEPCO informs the Nuclear and Industrial Safety Agency and the government of Fukushima Prefecture of the results of soil tests for uranium (, and ) carried out around the Fukushima Daiichi plant. The uranium found was considered to be natural, as its isotope ratios were consistent with the natural abundance. At 21:14 a cooling pump at reactor five stops. At 08:12 the next day, work began on a spare pump, and cooling was restored at 12:49. The reactor temperature had risen to 92.2 °C. The cause of the outage is suspected to be motor failure. Sunday, 29 May It is reported that 22 out of 23 radiation monitoring systems around the Fukushima plants were disabled by the earthquake and tsunami. Some were directly damaged, but most were disabled due to communication and power lines being cut. Even monitors equipped with backup satellite links failed, probably due to antenna damage. In Miyagi prefecture, 4 out of 7 were disabled by the tsunami, with the