M5.5 quake jolts wide area of northeastern Japan

Geez, once again kicking Okinawa out of Japan. Last night a magnitude 6.4 earthquake occurred off the northwest coast of Miyako Island

That area up there does not calm down, does it.

A land of earthquakes and aging NPPs doesn’t inspire confidence

kurisupisu

A land of earthquakes and aging NPPs doesn’t inspire confidence

None of the NPPs had problems with any earthquake. The problems at Fukushima were caused by the flooding, not by any ground movement.

The Fukushima NPP structures and reactor containment vessels and one emergency generator were badly damaged by the earthquake.

@wallace,

You've said this before, but I still haven't found any source that states the cause of the serious damage at the NPP was the earthquake and not the tsunami. Can you provide further info or a reliable source?

There were no indications that the main safety features of the plant were affected by the vibratory ground motions generated by the earthquake on 11 March 2011. This was due to the conservative approach to earthquake design and construction of nuclear power plants in Japan, resulting in a plant that was provided with sufficient safety margins. However, the original design considerations did not provide comparable safety margins for extreme external flooding events, such as tsunamis.

The national Diet later set up the legally-constituted Nuclear Accident Independent Investigation Commission (NAIIC, or National Diet Investigation Commission) of ten members which started its work in December 2011. One of the purposes of NAIIC was to provide suggestions including the “re-examination of an optimal administrative organization” for nuclear safety regulation based on its investigation of the accident. The NAIIC reported in July 2012, harshly criticizing the government, the plant operator and the country’s national culture. The commission’s report concluded that the accident was a “manmade disaster,” the result of “collusion between the government, the regulators and Tokyo Electric Power Co.” It said the “root causes were the organizational and regulatory systems that supported faulty rationales for decisions and actions.” The NAIIC criticized the regulator for insufficiently maintaining independence from the industry in developing and enforcing safety regulations, the government for inadequate emergency preparedness and management, and Tepco for its poor governance and lack of safety culture. The report called for fundamental changes across the industry, including the government and regulators, to increase openness, trustworthiness and focus on protecting public health and safety.

The NAIIC Chairman wrote: "What must be admitted – very painfully – is that this was a disaster 'Made in Japan.' Its fundamental causes are to be found in the ingrained conventions of Japanese culture: our reflexive obedience; our reluctance to question authority; our devotion to 'sticking with the programme'; our groupism; and our insularity.” The mindset of the government and industry led the country to avoid learning the lessons of the previous major nuclear accidents at Three Mile Island and Chernobyl. "The consequences of negligence at Fukushima stand out as catastrophic, but the mindset that supported it can be found across Japan. In recognizing that fact, each of us (every Japanese citizen) should reflect on our responsibility as individuals in a democratic society."

albaleoToday 03:11 pm JST

@wallace,

You've said this before, but I still haven't found any source that states the cause of the serious damage at the NPP was the earthquake and not the tsunami. Can you provide further info or a reliable source?

It was both and the tsunami caused the most serious damage.

But people post that the earthquake did no damage. Shortly after the earthquake and before the tsunami hit a radiation leak alarm went off. The force of the earthquake dislodged the No 2 reactor cap allowing radiation to leak and that is the position today. The internal radiation of the No 2 Reactor building is 10-15 SIEVERTS per hour.

The earthquake twisted the shaft of one of the emergency generators. It also caused cracks in the containment vessels. Several important buildings were damaged including the building which housed all the site documents and was later considered unsafe to enter. The radiation door to the safety control building was damaged and could not be shut.

The No 4 cooling pool was full of spent fuel, and the reactor was empty and came very close to collapsing. That would have been very serious.

There were three incoming power feeds needed to run the plant. One collapsed from the quake because they were installed on a dry river bed.

All this was published in the full reports by the different groups, which I read. IAEA, government, TEPCO, and some others by experts.

Sorry, but I can't be bothered to find those reports which I have already posted so many times.

The nuclear disaster was manmade and could have been avoided with more safety investment.

albaleo

If the Fukushima plant was hit by another powerful earthquake like on 3/11 it would be a very serious major disaster and that threat will remain until all the spent fuel is removed from the site and melted fuel retrieved some decades into the future. The time scale is a long one.

wallace

The Fukushima NPP structures and reactor containment vessels and one emergency generator were badly damaged by the earthquake.

Do you have a reference for that claim? I have not seen any reports like that. As far as I know, the generator failed because of the flooding, and not because of any ground movement. And all subsequent problems were caused by the failure of necessary cooling. Please show a source.

Thanks wallace,

There is a detailed account of the sequence of events at the link below (in Section 1.3). While various issues were caused by the earthquake, it seems that expected procedures were followed, one of which was starting the emergency power generators. I read it that it was the damage to those generators by the tsunami that caused the major problem.

https://www-pub.iaea.org/MTCD/Publications/PDF/AdditionalVolumes/P1710/Pub1710-TV1-Web.pdf

One emergency generator was damaged by the earthquake. There were photos on the net at one point of the damaged generator.

I was merely stating there was damage by the earthquake. Had there been no tsunami there probably would have been no meltdowns and explosions.

There was a problem with the No 2 reactor cap which was dislodged by the earthquake.

The earthquake knocked out the incoming power and the water supply needed to cool the reactors. There was no emergency water supply.

At the second plant Daini, the plant supervisor was quick to run out hose pipes for several km to get water to the reactors.

The nuclear disaster was the accumulation of many points including the lack of safety training for the operatives for more than 25 years. Lack of a safety manual. No one knew what to do in that critical moment.

The entire nuke village believed there could never be a nuclear disaster in Japan.

No abnormalities have been reported at the Onagawa nuclear plant, near Ishinomaki, the operator said.

How many earthquakes are NPPs meant to withstand and of what magnitude?

A new NPP and a sixty year plus plant would be different

Well, nobody can say until something breaks and that is what earthquakes do; they break things

kurisupisu

How many earthquakes are NPPs meant to withstand and of what magnitude?

A new NPP and a sixty year plus plant would be different

Exactly. Technology is changing. Gen III+ reactors do not need external power supply after shutdown, so a Fukushima style accident is impossible.