Wednesday, August 7, 2013

#Fukushima I Nuke Plant: ALPS Multi-Nuclide Absorption Vessel Itself Had Rust and Corrosion


TEPCO kindly updated us with the bad weld and rust on the batch processing tanks in ALPS multi-nuclide removal system (see my posts from June this year here, here, here and here) on August 7, 2013. But I thought the title of the page was funny (emphasis is by me):

「多核種除去設備バッチ処理タンクからの漏えいを踏まえたB系統の停止計画と追加調査結果

"Plan to halt Line B because of the leak from the batch processing tanks in Multi-Nuclide Removal System and the result of additional investigation"


Additional investigation?

It turns out that this additional investigation has found corrosion and rust in one of the multi-nuclide absorption tower vessels. The absorption material inside the vessel was due for exchange, so TEPCO decided to take a look inside the vessel. This is what they found:

From TEPCO's Photos and Videos Library 8/7/2013:

Flange of the inspection hole:


Rust around the weld, inside the vessel:


These were not supposed to happen.

From PDF document, page 2 (English labels are by me):


Here's the system diagram of ALPS. There are three lines, A, B and C.


In my June 20, 2013 post, I wondered:

how about the same tanks in other two lines? What about other tanks and vessels that are all welded?


The tanks and towers for ALPS were made by Toshiba (most likely Toshiba's subcontractor), and the weld was inspected by Toshiba before they were deployed at Fukushima I Nuclear Power Plant, according to independent journalist Ryuichi Kino when I asked him back in June when the batch processing tanks were found with bad weld and leak.

What has happened to the technological and manufacturing might of Japan? (Or was it a myth after all?)

4 comments:

Anonymous said...

They probably just do the same thing as everyone else: high-quality exports, garbage-quality local. Makes them look good to the rest of the world. Perfectly in line with how superficial humans are while they rot from the inside out.

Hikarius said...

Maybe the focus is shifted to the construction of aircraft carrier and the military buildup.

netudiant said...

Seems a clear case of design failure.
The stainless steel that the system is built of will corrode when in contact with warm salt water, especially if it is a little acidic.
The solution to this well known limitation is to line the steel with a protective layer of material such as polyethylene. Why this was not done initially is not clear, but it is now getting retrofitted. That will probably require the structure to be disassembled, so there will be a delay in the return to service of the ALPS.

Anonymous said...

No engineering or quality control.Just like the replacement parts for the California nuclear plant which is now permanently shutdown...for failure of things like 'welds..' and quality. Its too bad for the company who is trying to take and run with profits..the devices failed at both locations in a year or so. Wonder what happened to the 10 year or 20 year life expected for the metal. Kind of like the new life expectancy for Fukushima victims..month or year..not YEARS. Be ashamed if your name or company or country was part of this mess with ALPS or nuclear fabrication.

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