#Contaminated Water System: Leak Was from the Same Joint

It turns out the July 12 leak in AREVA's coagulation/coprecipitation unit was from the same location where the July 10 leak had happened.

If you recall, the July 10 leak was from the cracked PVC coupler that connected the PVC hose and a small metal tube welded to the bigger metal pipe. TEPCO replaced the PVC coupler with a metal coupler.

Well, that metal coupler, made of cast iron, was corroded away by ferric sulfates in the chemical fed through the hose in less than 2 days, and started to leak again. So, the July 12 version of the leak fix was to replace this corroded cast iron coupler with the stainless steel one and hope for the best.

TEPCO's Matsumoto said in the press conference on July 12 that they didn't think the cast iron coupler would corrode because it had metal plating. About 10 liters of the contaminated water and the chemical had leaked before the system was stopped.

Here's before and after photos from TEPCO on July 12:

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