#Fukushima Contaminated Water Treatment System: Hitachi's Desalination Unit Leak was from PVC Hose

Diposkan oleh Pengetahuan dan Pengalaman on Sunday, July 31, 2011

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):

東京電力は31日、福島第一原子力発電所の汚染水処理システムから、放射性物質を除去処理した後の塩水が、推定で約50リットル漏出したと発表した。

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.

 塩化ビニール製の配管の劣化が原因とみられ、未明の地震による影響は考えにくいという。

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.

 水漏れが起きたのは、処理後の水から塩分を取り除く「淡水化装置」から、副産物としてできる高濃度の塩水をタンクへ送る配管。同日午前10時50分ごろ作業員が発見し、30分後に装置を停止。配管を交換後、午後3時すぎに復旧した。原子炉への注水には支障はなかったという。

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.

 また午前8時13分ごろには、4号機の使用済み燃料一時貯蔵プールに水を送るホースから真水が霧状に漏れているのが見つかり、ホースを交換した。

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?