TEPCO is encountering delays in its efforts to pump out radioactive water flooding the basement of the unit 1, 2 and 3 turbine buildings, according to a report from Japanese news service NHK republished by the Japan Atomic Industry Forum (30 March).

TEPCO’s plan to pump the water into the turbine condenser hot well requires that water already inside the condenser to be pumped elsewhere, to suppression pool storage tanks. Pumping in the unit 1 basement to the 1600 ton capacity condenser began on 24 March at a rate of 6 m3/hr, and continues, TEPCO said. The 3000 ton capacity hot well of turbine condensers at unit 2 and 3 are full; unit 3 hot well pumping began on 28 March, and unit 2 hot well pumping began on 29 March.

The basements of the unit 2 and 3 turbine halls will also be emptied eventually. The presence of the water is preventing attempts to restore plant equipment, including emergency backup diesel generators.

TEPCO has also increased freshwater injection into the unit 1 reactor from 113 L/min to 141 L/min after its surface temperature increased from 213°C on 6am Monday 28 March to 329°C by 8pm. The reactor is designed to operate at temperatures up to 302°C under normal conditions. As a result, the reactor temperature decreased to 323°C by 6am Tuesday 29 March.

In other news, TEPCO began pumping freshwater into the unit 3 and unit 2 spent fuel pools on 29 March. Previously, a concrete pump had been pumping seawater into the unit 3 pool. At the unit 2 spent fuel pool, a temporary motor-driven pump briefly replaced a fire truck that had been pumping seawater. A malfunction in the pump forced TEPCO to resume pumping seawater with a fire truck.

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