Probably the same ubiquitous orange PVC hose at Fukushima I Nuclear Power Plant. The PVC hose is used to transport highly-concentrated saltwater from the desalination unit to the temporary storage tank, and the leak is considered to be due to the deterioration of the hose, after 1 month of use.
From Yomiuri Shinbun (7/31/2011):
TEPCO announced on July 31 that about 50 liters of saltwater leaked from the contaminated water treatment system. Radioactive materials had already been removed from the water.
According to TEPCO, the leak was probably due to the deterioration of the PVC hose used, and not the earthquake that hit the area in early morning.
The leak was found at the hose that transports the highly-concentrated saltwater from the desalination unit to the storage tank. A worker found the leak at 10:50AM on July 31, and stopped the unit 30 minutes later. The PVC hose was exchanged, and the unit was back online at 3PM. The company said there was no interruption to water injection in the reactors.
Also, at 8:13AM, [a worker found] the hose that sends water to the Spent Fuel Pool of Reactor 4 was leaking, spraying water in fine mist. The hose was replaced.
These hoses are probably Kanaflex, which the manufacturer rushes to make and deliver to TEPCO as fast as possible.
So how salty is this water coming out of the desalination unit by Hitachi that made the hose deteriorate badly in slightly over a month?
From TEPCO's information on July 15, before the desalination (by reverse osmosis) the chlorine concentration is 8,000 ppm. After the desalination, this number drops to 19 ppm.
So, the saltwater that goes through the PVC pipe has 7,981 ppm chlorine.
Another one to file under the "things don't add up" category. Initially, TEPCO had blamed just about every leak to the sloppy job by the workers. Now the company hints at the poor quality of the PVC hose. Is it really the case, or is there still some information to be forthcoming later?