As more details leak out about the stricken Fukushima Daiichi nuclear power plant, it’s become clear that something else is leaking—radioactive water from the cores of three damaged reactors.
Leaks have been a persistent problem at the plant since it was struck by an earthquake and tsunami on 11 March. Three reactors operating at the time of the quake went into meltdown after the tsunami wiped out emergency generators designed to circulate water through the cores. TEPCO recently admitted that all three units probably suffered complete meltdowns before workers could flood them with seawater.
Since then, reactor operators have kept water flowing to the cores and several fuel storage pools above the reactors. That same water appears to be flowing out into the basements of buildings and eventually the Pacific Ocean, where environmentalists and scientists have raised concerns about possible contamination.
The Tokyo Electric Power Company (TEPCO), which runs the plant, hoped to rectify the problem by pumping water into storage tanks until it can be reprocessed, but today Reuters reports that the storage tanks appear to be leaking.
And that’s just the start of the bad news because the reactors themselves appear to be leaking as well. TEPCO initially hoped that the leaks were largely coming from pipes that could be repaired, but they now concede that both the reactors’ pressure vessels and primary containment vessels, which are designed to contain an accident, are probably leaking water.
The leaks will probably force TEPCO to abandon its plans to set up a recirculation system that can cool the reactor cores. That’s a serious blow to efforts to bring the reactors to a safe temperature within months. Recirculation is far more efficient (and less radioactive) than simply dumping water into the cores. A new plan posted on 17 May seems to indicate that TEPCO will instead try to recirculate water from the basements of the damaged buildings into he reactor cores. It would be better than nothing, but a far cry from a closed loop efficiently cooling the reactors.
Meanwhile, new questions are being raised about the early hours following the accident. Logs seem to indicate chaos inside the control room, and indecision from company managers who were perhaps worried about the financial loss they would face if the reactors were ruined with seawater. A story in The Daily Yomiuri implicates prime minister Naoto Kan in the delays as well.
TEPCO has also released a preliminary report on the tsunami, which has previously unseen pictures of the damage (p. 15) and some pretty chilling snapshots of conditions in the plant before power was restored (p.71). Think gasmasks and flashlights.
Given all these problems it may be no surprise that some scientists are simply floating the idea of turning Fukushima into a nuclear graveyard. It would be a simple solution, but given the plant’s location on the coast, storing the waste there for millenia may be unrealistic.
For full coverage of the Fukushima disaster, go to Nature’s news special.
For a selection of our coverage in Japanese, see Nature Asia Pacific.