By Elona Malterre
 The Fukushima nuclear accident in Japan is as bad as the world’s worst nuclear reactor disaster at Chernobyl that left an uninhabitable “dead zone,” says an energy expert with ENMAX Corporation.
 The world is not getting an accurate picture of how dire the situation is at the Fukushima Daiichi nuclear facility, said Terry Tyler, ENMAX’s executive vice-president, chief technology officer and chief information officer. He holds an MBA in Finance and Management, an undergraduate degree in nuclear engineering and he worked for several years as a nuclear engineer.
 The situation at the Fukushima facility is “very dire,” with evidence of ongoing fission – melting of highly radioactive fuel, Tyler said in a talk presented by the Institute for Sustainable Energy, Environment and Economy (ISEEE) at the University of Calgary.
 “Long-term  . . . it (the Fukushima accident) is, I think, as bad as Chernobyl,” he said.
 In the Chernobyl disaster, in what is now the Ukraine, a reactor exploded on April 26, 1986, spewing a cloud of radiation over much of the Northern Hemisphere. A zone of about 30 kilometres around the plant was declared uninhabitable.
 As at Chernobyl, the three damaged Fukushima Daiichi reactors will need to be permanently entombed in concrete, Tyler predicted, adding that there also will be a radioactive “dead zone” around the facility for hundreds of years.
 Prior to joining ENMAX, Tyler was co-owner and founder of the consulting company Energex, which was the program manger for the post-Three Mile Island Industry Degraded Core Rulemaking Program, for the U.S. Department of Energy and the U.S. Nuclear Regulatory Commission.
 Tyler argued that the 1979 nuclear reactor accident at Three Mile Island in Pennsylvania wasn’t as serious as what’s happening at Fukushima. That’s because the Three Mile Island plant, even though it had a partial core meltdown in one reactor unit, still had intact all its emergency systems and heat sink systems necessary to cool the reactor. At the Fukushima facility, these systems were destroyed.
 Japanese nuclear regulators said the severity rating for the Fukushima accident was raised from 5 to 7 – the highest on an international scale overseen by the International Atomic Energy Agency – due to new assessments of the overall radiation leaks from the Fukushima Daiichi facility.
 Other experts disagree with Tyler’s assessment that the Fukushima accident is as bad as the Chernobyl reactor explosion.
 “Although the Fukushima accident is now at the equal (severity rating) level as Chernobyl, we should not consider the two incidents as the same. . . . Fukushima is not a Chernobyl,” Hiroshi Horiike, a professor of nuclear engineering at Osaka University, said in an April 12 Associated Press story posted to the Energy Central Professional website (http://www.energycentral.com/).  
 According to the story, “Japanese officials said the leaks from the Fukushima plant so far amount to a tenth of the radiation emitted from Chernobyl, but about 10 times the amount needed to reach the level 7 (severity rating) threshold.”
 However, Japanese officials have also acknowledged that total emissions from Fukushima could eventually exceed Chernobyl’s, especially since restoring regular cooling systems to the crippled Fukushima reactors is expected to take months.
 On March 11, Japan was hit with a magnitude 9.0 earthquake that caused extensive damage along the country’s northeastern coast. The tsunami triggered by the earthquake inundated the coast with waves of up to more than 12 metres high.
 At the Fukushima nuclear facility, the tsunami overtopped the plant’s protective concrete seawall, knocking out reactor cooling systems and backup diesel-fueled power generators.
 Emergency power was crucial to keep cooling systems running for the reactors in the event of an emergency shut down. Loss of cooling led to a buildup of hydrogen gases inside the reactor buildings and explosions at three reactors, which released radioactive material into the atmosphere.
 Japanese officials have pointed out that unlike at Chernobyl, the Fukushima Daiichi facility has had no explosions of reactor cores, which are considered more serious than hydrogen explosions.
 But in an interview after his ISEEE talk, ENMAX’s Terry Tyler told EnviroLine that the situation at Fukushima is much worse than is being reported.
 He pointed to the April 12 Associated Press story, which describes a terabecquerel as a trillion terabecquerels – a measure of radiation emissions. According to the story, “The Chernobyl incident released 5.2 million terabecquerels of (radiation) into the air.”
 In comparison, Japanese officials said that the accident at the Fukushima facility has released just one-tenth of this radiation into the air, or the “equivalent of 500,000 terabecquerels of radiation from iodine-131.”
 Tyler said the comparison is flawed. “The problem with this comparison  . . . is they’re comparing all of the radiation released from Chernobyl into the air to only one radioactive isotope (iodine-131).”
 When a uranium atom is split in the fission process, “a whole spectrum of radioactive elements” is formed, including iodine-131, Tyler explained.
 “But you’ve (also) got strontiums and cesiums and nitrogens and oxygens and argons. And all of these radioactive elements are released the minute that this (fission) transpires. And for them to say that this is only ten per cent of what was released at Chernobyl is a total mistake.”
 In his ISEEE talk, Tyler noted that iodine-131 is only created during fission, and the radioactive isotope has an eight-day half-life.
 “If it’s got an eight-day half life, it’s been one month since the event, and I’m seeing iodine-131 levels today that are 10,000 times higher than they were a week ago, (which means) you’ve got to have a nuclear chain reaction taking place.” 
 Contrary to some news reports, the situation at the Fukushima Daiichi nuclear facility “isn’t under control,” Tyler added.
 The only rationale for officials describing the situation as “stable” is because they know that fission is still taking place, he said. This means at least one reactor unit’s melting core of fuel “is just sitting there, slowly eating its way into the ground.”
 One uranium pellet the size of the tip of a person’s pinky finger has the equivalent energy of 17,000 cubic feet of natural gas, 1,780 pounds of coal or 149 gallons of oil in British Thermal Units, he noted.
 At the Fukushima Daiichi reactors, these pellets are stacked inside   zirconiam tubes surrounded by water and contained in the reactor pressure vessel.
 The reactor core’s structural integrity “maintained all those pellets in a controllable chain reaction.” But with the explosions inside the reactor buildings and several major aftershocks following the main earthquake, “these pellets are now free to move anytime, they have no structure,” Tyler said.
 “That’s important because you get enough of these (pellets) in a lump, have a stray neutron come along, and you’ve got a prompt criticality event” (when ‘spent’ nuclear cores restart a nuclear reaction).
 “My supposition is we’re continuing to have fission . . . because all these pellets are now to free to move at random,” Tyler said. “All this stuff is just collapsing down inside the reactor pressure vessel itself. It can eventually eat through the bottom of the reactor pressure vessel.” According to a report by the Atomic Energy Society of Japan, nuclear fuel inside reactors No. 1 and No. 3 has partially melted and settled at the bottom of pressure vessels in the shape of grains.
 A large buildup of melted nuclear fuel could become a molten mass hot enough to damage the containers and eventually leak huge amounts of radioactive material, according to a story by the RT media outlet in Moscow (see http://rt.com/news/fukushima-tepco-compensation-mineral/print/).
 The risks of radiation leakage outside the Fukushima facility are also being downplayed, Tyler maintained.
 There is evidence that radioactive plutonium has leaked outside the plant, he said. “The bad part about plutonium is that it’s more toxic (than other radioactive elements). It can kill you from a toxicity perspective before you have any of the effects from radiation.” 
  The rate of decay of heat from the three damaged reactors is “a very critical thing to talk about,” Tyler said.
 The No. 1 reactor unit at the Fukushima Daiichi nuclear facility was producing about 450 megawatts of electricity and about 1,500 MW of thermal (heat) energy when it was shut down, Tyler said.
 The unit is “roughly 33 per cent efficient in converting energy into electricity at the back end,” he explained. Under normal operation, “the rest (of the energy) is vented as water vapor out the cooling towers.”
 But even three months after the reactor has been shut down, it will still be “generating eight megawatts of heat that has to be dealt with . . .”
 However, the Fukushima facility’s cooling water system ‘loops,’ which allow for coolant to be cooled using a unique ocean heat sink, were damaged. This caused what’s known as a “Loss of Heat Sink.” Even if power had been restored, there was no immediate way to repair the damaged water loops and thereby cool the reactors.
 Emergency workers have been using seawater to try to cool the reactors and possibly also their spent fuel pools. However, seawater is extremely corrosive and highly mineralized, which can speed up the rate at which undamaged fuel cladding is degraded.
 The situation for workers is “darned if you do, and darned if you don’t” in resorting to seawater as coolant, Tyler said.
 Emergency workers also started, on April 4, deliberately discharging low-level radioactive water from the facility into the ocean, to make room at the site to store water with much-higher radiation readings.
 Construction of a steel wall in the sea in front of reactor No. 2, to prevent further leakage of radioactive water into the ocean, is underway. The contaminated water is still penetrating the drainage system of the rector and is being collected into the tank of the condensing system.
 Asked if he thinks we’ve seen the worst of the disaster, Tyler replied that he didn’t think so because he believes nuclear fission is still ongoing inside at least one reactor.
 As with Chernobyl, “You’ll see a dead zone” around the Fukushima Daiichi facility, he said, adding he thinks the mandatory evacuation zone should be expanded to at least 50 kilometres from the current 30 km.
 Ultimately, he said, “we’re going to have to do what we did at Chernobyl. We’re going to have to erect some sort of (concrete) sarcophagus” atop the damaged reactors, to seal them.
 However, he added: “It’s going to take months to get in hundreds of thousands of tons of concrete. You’ve got to build a road infrastructure, rail infrastructure. That’s all demolished.” EnviroLine