#Fukushima I Nuke Plant: Pipe Shavings Causing the Decrease in Water Flow, TEPCO Thinks

Incurious TEPCO's conclusion for now is that the white pieces floating in the buffer tank and caught by the strainer are the shavings of plastic pipes and they are the cause of the decreased water flow into the reactors.

From Yomiuri Shinbun (9/6/2012):

福島第一の注水量低下、配管の削りかすが原因か

Decrease in the amount of water injected [into the reactor] caused by shavings from the pipes?

福島第一原子力発電所１～３号機の原子炉を冷やす注水量が必要量を下回った問題で、東京電力は６日、ポリエチレン製配管の削りかすが弁や配管などに詰まった可能性が高いと発表した。

TEPCO announced on September 6 that it was likely that the shavings from the polyethylene pipes were clogging up the valves and pipes and causing the amounts of water injected into the reactors at Fukushima I Nuclear Power Plant to fall below the necessary amounts for cooling.

　東電はこれまで、鉄さびが配管につまった可能性を示唆していたが、注水量の低下は、処理した汚染水を冷却用タンクに移す全長２・７キロ・メートルの配管を８月３０日にポリ塩化ビニール製からポリエチレン製（直径１５センチ・メートル）に切り替えた後に起こったことを重視。削りかすは配管の切断作業などで出たとみられる。タンク内や、冷却装置のフィルター部分からは、削りかすとみられる白い物質が見つかっている。

TEPCO had hinted at the possibility of metal rust clogging the pipes. However, the company thought it important that the problem started to happen after August 30, when the 2.7-kilometer pipes that transport the treated water to the cooling tanks were switched from polyvinyl chloride pipes [probably Kanaflex] to polyethylene pipes (15 centimeter in diameter). The shavings are considered to have been generated when the pipes were being cut. White substances that looks like the shavings have been found inside the [buffer] tank and on the filter of the cooling equipment.

If it is true, I don't know what to say, other than that TEPCO is fast running out of money and quality subcontractors. This is decidedly not the "nuclear plant" spec.

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