On July 29, PBS’s NOVA aired the documentary “Nuclear Meltdown Disaster”, concerning the Fukushima accident of mid-March, 2011. Early on, the narrator asked, “What will it take to save the country (Japan) from radiation?” The narration said that while the accident itself was bad, it could have been much, much worse – so bad, in fact, that the Tokyo metropolis would have had to be evacuated.
What could be worse than three meltdowns and three hydrogen explosions releasing enough radioactive material to force evacuations for more than 75,000 people? The answer came in the first spot with former Japanese Prime Minister Naoto Kan. Kan said that during the first days of the crisis he had been told that if the worst possible scenario developed, he would have to consider evacuation of Japan’s capital city. The thought of such a monumental evacuation became Kan’s nightmare.
The documentary neglected to explain the reason behind Kan’s fear. On March 12th, the day of the first hydrogen explosion at F. Daiichi, Kan and his cronies concocted an utterly fantastic scenario. In a Japan Times interview posted on 8/31/13, Kan said, “Fukushima had six reactors at the No. 1 site, and four at the second [Daini] site. It [both sites] had 11 pools for storing used nuclear fuel. If all those had become uncontrollable, then there could have been many times more nuclear fallout than from Chernobyl. Radiation would have fallen over a very large area, including Tokyo — possibly requiring the evacuation of 50 million people. That would have dealt a massive blow to the country.”
The NOVA video literally bent over backwards to make it seem that Kan’s nightmare was justified. Unfortunately, it was not.
Of the six units at Fukushima Daiichi, only three were operating at the time of the earthquake. The first shaking by the massive temblor caused automatic “trips” with all three units, sending the control rods into the cores, stopping the chain-reaction. In nuclear jargon, there were three immediate SCRAMs. Although the quake caused the northern half of Honshu to experience an electrical black out within minutes, all emergency systems and power supplies kicked in, placing all three units at F. Daiichi in a safe condition.
The other three units were already shut down. Unit #4 was in the middle of a refueling outage, and there was no fuel in the reactor. Units five and six were near the end of extended refueling and maintenance periods, and their cores had been recently reloaded. When the subsequent tsunami caused the full station blackout for units #1 through #4, one of the emergency diesels for units 5 & 6 survived, powering their emergency systems. Thus, F. Daiichi units 4, 5, and 6 were in no danger of meltdowns.
Ten kilometers to the south, the four units at Fukushima Daini were at full power when the quake hit, and all four instantly SCRAMed. The quake’s blackout caused all emergency systems and power supplies to kick in, and all four reactors were in a safe condition. After the tsunami hit, there happened to be barely enough power coming into the F. Daini to keep a full station blackout from happening through a 500kv connection. While F. Daiichi had a very limited supply of fresh water to cool the three overheated cores, F. Daini had a fresh water stream nearby that kept them from running out. For these and other reasons, F. Daini was in no immediate danger of any meltdowns.
So, where did Kan get the idea that it was possible for all ten Fukushima units to become “uncontrollable”? He said he could not trust the information he was getting from Tepco and the government’s nuclear watchdog NISA. Further, he believed that Tepco was planning on abandoning F. Daiichi and just let the accident run its course…all by itself. Moreover, he believed that the abandonment would eventually result in all six spent fuel pools drying out, causing cataclysmic fires that would spew many times more radioactive material in the air than had come out of Chernobyl. The hypothetical toxic cloud would spread and soon engulf F. Daini, forcing its complete abandonment. Eventually, the radioactivity would engulf the Tokai station 150km to the south of F. Daiichi, forcing its abandonment. Without operator control, all five units at F. Daini and Tokai would melt down and their fuel pools would inevitably burst into flames, greatly exacerbating what was coming from already-evacuated F. Daiichi. The combined radioactive releases would descend on the Tokyo megalopolis and force Kan to have every man, woman, and child evacuated.
Kan’s nightmare would make a great apocalyptic science fiction movie, but nothing of th sort was even remotely possible.
Kan’s nightmare was based on…well…no-one’s sure where he and his underlings came up with the notion. Kan admitted it was a hunch on his part. The Times report said, “…a hunch [Kan] says was given scientific backing on March 25 when Japan Atomic Energy Commission chairman Shunsuke Kondo presented him with a similar scenario.” Kan said his hunch “informed” him that he should invade Tepco’s Tokyo headquarters on March 15th in response to reports the company intended to pull all their staff out of the Fukushima facility.
However, Tepco never considered abandonment of F. Daiichi. The post-accident record compiled by the government’s in-depth accident investigation (NAIIC) showed that Tepco never had any idea of the sort! After the unit #4 hydrogen explosion at daybreak on March 15th, F. Daiichi plant Manager Masao Yoshida realized that the situation with the four damaged units had peaked. The worst that could happen, had already happened. Low pressure fire pumps were injecting water into the damaged reactors. A kilometer-long cable was being planned to connect station with a functional transmission line inland. Until that connection was made, there was no reason to keep the majority of workers at the station. They sorely needed rest and recovery time after five days of frantic activity. Plus, any radiation exposure over the next few days would be unwarranted since most of the on-site staff literally had nothing to do. Yoshida told Tepco in Tokyo they he wanted to have them go to low-radiation exposure locations. A total of seventy qualified operators would remain in control of all six units. Unfortunately, the retreat of the majority of the staff was called an evacuation by Tepco and understood as abandonment by one of Kan’s officers.
Cabinet Secretary Yukio Edano told Kan of F. Daiichi’s alleged abandonment, and said it would initiate a “demonic chain reaction” of plant meltdowns that could result in the evacuation of Tokyo, 250 kilometers to the south. He explained, “We would lose Fukushima Daini, then we would lose Tokai. If that happened, it was only logical to conclude that we would also lose Tokyo itself.” Edano told the NAIIC that he got his information from a Tepco official in Tokyo. If he did, he misunderstood what he had heard. As a result, Kan stormed into the Tepco offices later that day and ordered them to not do something they did not plan on doing. Kan’s fear of F. Daiichi being evacuated, causing a domino-like sequence of abandonments at F. Daini and Tokai, was entirely unfounded.
But, what about the spent fuel pools and the possibility of them bursting into flames? 10,000 spent fuel bundles were stored in relatively unprotected pools near the damaged reactors. On March 15th, Japan’s Self Defense Force helicopters tried to drop large volumes of water into the pools. It was essentially a failure because the released waters quickly spread into ineffective sprays as they fell. However, the pilots reported that none of the pools were boiling and there were no uncovered fuel bundles.
This ought to been the point at which the soothing words of relief “Tokyo is saved” should have been in the narration…but it wasn’t. The documentary continued the gripping scenario of a Tokyo evacuation possibility using some questionable reporting.
On March 16th an irresponsible report came out of the American Nuclear Regulatory Commission saying the exposed pools were boiling and one actually had spent fuel bundles partially uncovered. It seems they didn’t believe the SDF helicopter pilots. It was not until March 17th, and the influx of water from mobile high-pressure concrete pumper trucks began, that the documentary sounded the “all clear”. The documentary purports that then, and only then, was the possibility of spent fuel fires eliminated. Tokyo was saved! The fatal flaw is that there is absolutely no way that dried-out spent fuel bundles could heat up enough to burst into flames.
The fictional notion of spent fuel fires was first postulated in WASH-1400, published by the NRC in 1975. Within its voluminous pages we find risk estimates caused by the hypothetical over-filling of SPFs with used fuel bundles, the pool being somehow drained, the stored fuel bundles dried out for a period of many days, resulting in the dried fuel bursting into flames that spawn a toxic cloud of massive proportions. But, there was no realistic explanation in WASH-1400 as to how temperatures in a dried-out pool would get high enough for the spent fuel inside to burn. It was assumed the decay heat from the stored bundles could cause the support grid for the bundles to fail, causing the fuel bundles to fall into a pile, and get hot enough to burn deep within the disarray, spread to the whole mass, and release huge volumes of contained fission products into the atmosphere.
It is critical to note that WASH-1400 was categorized as “obsolete” and replaced with NUREG-1150 in 1991. The NRC literally realized it was wrong. Since WASH-1400 was created with government funds it could not be expunged from the system. It technically remains on the books and its erroneous contents are often used to support many frightening reports conjured up by professional antinuclear pundits, although it is no longer worth the paper it was printed on.
In theory, Zircalloy tubes might ignite if they reach 900o Celsius. However, this theory has been tested by expert researchers. A chunk of the metal was heated up to 1,200o C, and it did not burst into flames. With this in mind, how hot could a large number of spent fuel bundles get if they are all dried out and were allowed to heat up for an extended period of time? A few hundred degrees C, in isolated locations, at most. What is never taken into account by believers in the SFP fire scenario is that natural convection of the heat to the surrounding atmosphere would be so great that reaching the theoretical ignition point of 900oC, even in the most severely compacted locations, is virtually impossible!
At this point, we might ask where Kan’s “hunch” concerning SFP fires came from? We find a possible answer in his Japan Times interview. After graduating from college in 1970, Kan cut his political eye teeth as a social activist. In 1980, he was elected to Japan’s lower house in the Diet (congress), which is equivalent to the US House of Representatives. He was, at the time, a member of Japan’s Socialist Democratic Party which staunchly refrained from support of Japan’s nuclear energy program. He remained in the SDP until 1996, when he and Prime Minister Hatoyama, also of the SDP, both left the party and created the Democratic Party of Japan. Kan told the Times, “When I first stood for election I was quite critical of nuclear power.” In other words, he was an anti-nuke when first elected, and was a member of the tacitly antinuclear SDP for more than 15 years. It is not unlikely that he became familiar with many antinuclear dogma’s during that period of his life, one of which was (and still is) a belief that an SFP fire is a real, nigh-apocalyptic possibility. To the contrary, it is a decades-old fiction perpetrated by steadfast antinuclear organizations.
Yes…Tokyo was saved, but not from a toxic cloud of radioactive material. It was saved from the specter of a chaotic, life-threatening, completely unnecessary evacuation. Records show that dozens of people died in the frenzied evacuation of 75,000 Fukushima residents in 2011. How many needless deaths would there have been if Tokyo’s multi-millions had been told by their government to flee?
NOVA’s documentary seems to be little more than a determined attempt to vindicate Naoto Kan’s paranoiac, antinuclear Fukushima nightmare. The documentary’s “Tokyo-at-risk” scenario is based on vacuous premises; Tokyo was never in danger of a toxic radioactive cloud, and SFP fires are nothing more than a false, antiquated assumption.
1. Naoto Kan Speaks Out; Japan Times, August 31, 2013. http://www.tepco.co.jp/en/press/corp-com/release/2015/1256987_6844.html
2. Japan Considered Evacuating Tokyo in Nuclear Crisis; NY Times Asia-Pacific; February 27, 2012. http://www.nytimes.com/2012/02/28/world/asia/japan-considered-tokyo-evacuation-during-the-nuclear-crisis-report-says.html?_r=1