This article first appeared in Japanese on JBpress on May 31.

They should have evacuated a wider area--and sooner. But their priority was saving the reactors, not protecting residents, says Japanese nuclear industry insider Gen Matsuno, whose prescient nuclear disaster prevention book published four years before Fukushima was ignored.

As part of my journalistic research into the Fukushima accident I found myself on the island of Shikoku in the city of Matsuyama.

I had come across a book on how to prevent and prepare for nuclear power plant accidents. I had been scouring the literature on nuclear accidents after the March 2011 earthquake, and when I found and read this book I was so shocked I nearly fell out of my chair.

Why? Because the book specifically detailed how to prevent all damage from nuclear accidents, including radiation exposure to local residents in their aftermath.

If the damage could be foreseen to this extent, why weren't the local residents saved from radiation exposure? This question was imprinted in my mind.

Why did we end up in such a grave situation with several millions of residents exposed? Why weren't they evacuated? In my ongoing interviews on Fukushima I had sought but failed to find answers to these questions.

So I had been visiting the Fukushima prefectural government and local municipalities asking what evacuation plans were in place and what disaster planning exercises had been conducted. I've been reporting on my discoveries in a series of articles of which this is the latest.

But most of my big questions were answered clearly in this book. So I knew that the measures actually taken by government were somewhat primitive in that they couldn't even ward off things that had been foreseen.

Shortcomings in official disaster prevention systems

I was sure the book had been written after the March 2011 earthquake. But when I checked the publication data I was surprised to find that it wasn't. It was published in January 2007. In other words, the book's author had accurately predicted a Fukushima-type accident four years before it happened.

Who, then, is the author? Is he an anti-nuclear researcher from outside the 'nuclear village'? It turned out he isn't. He's a former engineer of Shikoku Electric Power Company, a regional utility that had been operating a nuclear power plant since 1978.

He worked at the utility, then its nuclear plant, and then the Japan Nuclear Energy Safety Organization (JNES), a government organization for ensuring nuclear energy safety. In other words he was an industry insider, part of the nuclear village.

And yet from his position within the establishment he had been pointing out the shortcomings of the disaster prevention frameworks for protecting residents from nuclear plant accidents.

He published and shared his expertise a full four years before Fukushima. What's more, it's not some esoteric tome aimed at experts. It's a 170-page book that costs around 25 US dollars. I bought it on Amazon.

If this much was understood, what exactly were the power industry and the nuclear village up to? Why didn't the government use this knowledge to prepare properly for nuclear accidents?

I really needed to speak to this man. Because of his position within the power industry he might refuse to talk to me, I thought. I called his mobile with some trepidation but when I got through he agreed immediately to an interview, and before I knew it I was on a plane to Matsuyama.

Designer and operator of nationwide nuclear disaster response systems

His name is Gen Matsuno and I met him in his home city of Matsuyama, famous for its hot springs and castle. He joined Shikoku Electric Power in 1967 straight after graduating from the University of Tokyo and worked there for his whole career until retiring in 2004.

We met at a local cafe where the soft-spoken and gentlemanly Matsuno explained what exactly he did. I was surprised to hear that he had been responsible for developing and operating Japan's nationwide response systems for nuclear accidents.

In his time as head of the Emergency Response Technical Development Group of JNES, Matsuno was tasked with reforming and putting into practical use emergency response support systems or ERSS. ERSS are important systems for sending data such as reactor pressure and temperature readings and radioactive material emission projections to offsite centers and related Tokyo departments when a nuclear accident occurs.

If the much talked-about SPEEDI system is the 'mouth' for reporting movements of the radioactive cloud, ERSS is the 'eyes and ears' for gathering information on the other side of the coin, the reactors themselves. Matsuno, naturally, is well versed in both ERSS and SPEEDI.

He has also served as a nuclear disaster prevention training lecturer. This training is also taken by specialist nuclear disaster prevention officials of the Ministry of Economy, Trade and Industry who monitor nuclear power plants' disaster prevention responses. In other words Matsuno's book is a kind of textbook and with the March 2011 earthquake the government failed the test.

What this means is that METI and the Nuclear and Industrial Safety Agency under it must continue to assimilate the knowledge left by Matsuno in his book.

Before we question why residents weren't evacuated we have to ask why SPEEDI data wasn't used for evacuating them. If SPEEDI's essential functions had been used, they would have been able to predict that the radioactive cloud had travelled northwest to Minami-Soma and Iitate and they could have warned and evacuated the areas' residents.

I broached each of the relevant questions with Matsuno. His answers were all clear and convincing, befitting of a true nuclear disaster prevention expert.

'Article 15 report' should have triggered immediate evacuation

Ugaya: "First, the government has been saying that they did not publish SPEEDI data because it was inaccurate due to damage to thermometers and pressure gauges from the high temperature and pressure of the reactors. But that just doesn't make sense: I can't believe that systems specifically designed for use in accidents were useless when one actually occurred."

Matsuno: "Frankly, if I had been there I would have projected the scale of the accident in five seconds, even without SPEEDI, and then issued an evacuation order. Because a station blackout is one of the severe accident scenarios in disaster prevention planning, they should have been prepared for one. They should have known that information flow ceases in a station blackout and been able to deal with that scenario."

At this point I was already stunned.

From my impressions right after the earthquake I had thought that how a nuclear accident would unfold could not be predicted.

Ugaya: "What do you mean?"

Matsuno: "Nuclear disasters can be predicted 100 times more accurately than typhoons or avalanches."

Ugaya: "At first nobody knew how much radioactive material had been released at Fukushima Daiichi, correct? And based on that they couldn't work out the appropriate evacuation radius, right?"

Matsuno: "That's not true. Even if they didn't know the precise amount a rough estimate would have been enough to work it out."

Saying that, Matsuno flicked through the pages of his own book and checked the figures for noble gases released in the Three Mile Island and Chernobyl accidents.

Matsuno: "The Three Mile Island accident was on the order of 5x10¹⁶ becquerels. The Chernobyl accident was on the order of 5x10¹⁸ becquerels. So they could have assumed that the Fukushima Daiichi accident was on the scale of 10¹⁷ becquerels.

"At Three Mile Island they evacuated a ten-kilometer radius. At Chernobyl it was thirty kilometers. Given that Fukushima Daiichi was between these two it should have been somewhere around 22 to 25 kilometers. The point is they should have got the residents out of there. I would have thought of it in five seconds. As soon as they confirmed a station blackout they should have assumed a containment vessel breach and evacuated residents in a 30-kilometer radius within 25 hours."

Ugaya: "At what point do they know it's a station blackout. How is this decided?"

Matsuno: "It's simple--the government knows it's a station blackout when the plant issues a nuclear emergency situation report to it in accordance with Article 15 of the Act on Special Measures concerning Nuclear Emergency Preparedness. For Fukushima Daiichi, this happened at 4:45 p.m. on March 11. At that point they should have assumed that the containment vessels could have failed and that radioactive materials could have leaked. That's when they should have started evacuating."

I was taken aback. Now that he mentioned it I remembered. Power companies are legally required to notify the government of major accidents requiring evacuation of local residents. Established standards are in place to ensure that they don't try to hush up an accident. If a power company has issued an 'Article 15 report' on station blackout and cooling system failure, it means that the containment vessel may have been breached, which means radioactive materials may have leaked.

An Article 15 report was issued only an hour and 59 minutes after the earthquake struck at 2.46 p.m. So from a disaster prevention perspective, the disputes about how long it took from station blackout until radioactive materials were released and whether or not there was a meltdown are irrelevant.

Once the Article 15 report was issued, the government should have started its nuclear disaster prevention response to protect residents from radiation exposure.