Monday, 28 March
High levels of radiation from contaminated water hindered work on restoring the cooling pumps and other powered systems to reactors 1-4.[135]The Japanese Nuclear Safety Commission reported that it assumed melted fuel rods in Unit 2 released radioactive substances into cooling water which subsequently leaked out through an unknown route to the Unit 2 turbine building basement.[citation needed] In hopes of reducing the amount of water leaking, TEPCO reduced the amount of water pumped into Reactor 2 from 16 tons per hour to 7 tons per hour, despite the priority of cooling the reactor core. Confirming concerns, the temperature in the reactor raised by 20°C. Highly radioactive water was also found in three “trenches” (tunnels that house electrical wires from the turbines) which stretch toward, but do not connect to, the sea.[136] Water levels in trenches of Units 2 and 3 were 1m below the level at which they would overflow to the sea, while the Unit 1 trench was 10cm from overflowing. TEPCO reported they used sandbags and concrete to prevent an overflow at the opening of the tunnel.[137] TEPCO confirmed finding low levels of plutonium in five samples from 21 March and 22 March,[138] concluding that “two samples out of five may be the direct result of the recent incident.”[139]
Tuesday, 29 March
Radiation reaches the UK. Very low levels of radioactive iodine detected in Glasgow and Oxfordshire [140]