Japan Nuclear Corrosion Spurs Inspections

TUESDAY, JANUARY 17, 2017


Inspections of pipes at nuclear sites in Japan have been conducted for decades without removing insulation, and now more thorough check-ups are reportedly revealing considerable corrosion.

The Japan Times reported Sunday (Jan. 15) that a thorough inspection of ventilation pipes at the currently idle Shimane 2 nuclear reactor revealed extensive corrosion and holes, including one that measured 30 centimeters by 100 centimeters, or about 3 square feet.

The revelation was reported by Chugoku Electric Company to Japan’s Nuclear Regulation Authority, the newspaper says, and it comes at a time when Japan is readying more reactors to be restarted after a mass shutdown five years ago. The recent inspection was reportedly the first time the insulation had been removed from the pipes since the reactor opened—in 1989.

Inspections Planned

Citing unnamed sources, the Times says the NRA plans thorough inspections of all of Japan’s 42 viable commercial reactors in light of the problems uncovered at the Shimane plant. The newspaper reports that NRA officials have said the corrosion may violate nuclear standards.

NRC officials at Fukushima
U.S. Nuclear Regulatory Commission, CC BY 2.0, via Wikimedia Commons

Japan shut down its commercial nuclear reactors after the tsunami-triggered nuclear disaster at the Fukushima Daiichi plant in 2011.

Shimane is located on the coast, leading to speculation that salty air may have played a role in pipeline corrosion.

Nuclear Restart

Japan shut down its commercial nuclear reactors after the tsunami-triggered nuclear disaster at the Fukushima Daiichi plant in 2011. In 2015, the country began to restart some of them; so far, the Sendai 1 and 2 reactors and Ikata 3 have returned to service. (Two reactors, Takahama 3 and 4, were returned to service, but then idled again due to lawsuits.)

According to the Times, two of the reactors that are currently in operation—Sendai 1 and Ikata 3—have not undergone thorough check-ups in which pipe insulation is removed since they returned to service.

Past Corrosion Problems

Corrosion has played a part in safety lapses at nuclear facilities in Japan before. At Fukushima, the same site where the 2011 tsunami led to meltdowns and radioactive releases, an incident took place in 1991 in which corrosion in pipes conveying seawater for cooling purposes led to a flood in the turbine building.

   

Tagged categories: Asia Pacific; Corrosion; Insulation; Nuclear Power Plants; Pipes; Quality Control; Salt exposure

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