Why did the pressure go up in that particular set of towers (most upstream of the 4 sets)? Because a valve was closed shut downstream. TEPCO hinted it may have been a human error, that a worker closed that downstream valve by mistake.
The total amount of water leaked was more than 6,000 liters [or 6 tonnes].
TEPCO will replace the ruptured "rupture disk" as well as the same disks for the other three sets of towers, and hopes to start the full run by midnight on June 17.
I was told by a former TEPCO nuclear plant engineer that something else is likely involved when the company wants to blame workers for a malfunction or an accident. We'll see if that's the case here.
The contaminated water situation must be getting really bad for TEPCO to hurry on with the full run that will process the highly contaminated water heavily mixed with seawater.
On the side note, Yomiuri Shinbun reports that the CEO of Areva, Anne Lauvergeon, will not be reappointed at the end of June, in the decision made by the office of the President of France, despite the urging by the company's executive board. Areva is 90% owned by the French government, and the CEO is rumored to have had disagreements with President Nicolas Sarkozy. The new CEO is going to be Luc Oursel, current COO of the company in charge of international marketing and projects. Oursel's name was missing in the letter by the company's executive board urging the reappointment of Anne Lauvergeon, as Reuters reports.