Friday, March 16, 2012

Nuclear engineer Gundersen describes aftermath of Fukushima-Daiichi

Nuclear options

The Commons
Nuclear engineer Gundersen describes aftermath of Fukushima-Daiichi disaster
Olga Peters,The Commons, [Mar 14,2012]
BRATTLEBORO—Nuclear engineer and former industry senior vice president Arnie Gundersen said he used to think people needed nuclear power.
Only a few companies like Entergy we couldn’t trust, he said at a Vermont Yankee forum held Sunday to mark the one-year anniversary of the nuclear meltdown in Japan.
The nuclear disaster at the Fukushima Daiichi plant, however, pushed Gundersen from okay to no way.
“We are not smart enough to anticipate what Mother Nature can throw at us,” he said. “This is what pushed me over the line.”
The forum followed an “evacuation” march hosted by the Safe & Green Campaign, an anti-nuclear group. Approximately 250 activists walked from Entergy’s Vermont Yankee nuclear power plant in Vernon seven miles north to the River Garden downtown.
A recent federal court ruling by Judge J. Garvan Murtha stayed the nearly 40-year-old plant’s closure on March 21, when the plant’s state-issued Certificate of Public Good expires. The Nuclear Regulatory Commission (NRC) gave its preliminary approval to extending the plant’s federal operating license by 20 years on the day before the Fukushima disaster.
Before Gundersen spoke, a chorus led audience members in singing the Vermont state anthem, followed by a moment of silence to remember people affected by the earthquake and tsunami that struck Japan last year and caused considerable damage to the Fukushima Daiichi nuclear complex.
Like several of the Fukushima reactors, Vermont Yankee uses the same Mark 1 containment design created by General Electric in the late 1960s.
Gundersen said he hoped Sunday’s walk sent the message that VY should shut down.
“I think all Mark 1 reactors should be,” he said. “That’s not just the opinion of an activist.”

Blow over and splitting a country

Gundersen told the audience that as an expert assigned to Three Mile Island in Pennsylvania, he witnessed the federal government and the nuclear industry gloss over the nuclear-related injuries after a partial reactor meltdown in March 1979.
“I vowed to dedicate my life to seeing that type of cover-up not happen again,” he said.
According to Gundersen, governments and the industry have locked away much of the reliable information on nuclear accidents like the 1986 meltdown of a Soviet reactor in Chernobyl. For example, Russian scientists were jailed for five years after that catastrophe, he said.
Gundersen and his wife, Maggie, operate Fairewinds Associates, a paralegal services and expert witness firm that Maggie, a journalist, mediator, and paralegal, founded in 2003. The Gundersens also operate Fairewinds Energy Education Corp., a nonprofit aimed at educating the public about nuclear power and energy issues.
According to Arnie Gundersen, former Soviet president Mikhail Gorbachev credits the 1991 collapse of the Soviet Union not to perestroika, the restructuring of the Soviet political and economic systems, as commonly asserted, but to the Chernobyl disaster.
Japan’s recovery from Fukushima and the tsunami that precipitated the catastrophe is estimated to cost a half-trillion dollars, Gundersen said, or the equivalent of the amount the county saved in energy costs over the last 40 years from using nuclear power.
Nuclear power might serve as a reliable, low-carbon-emissions energy source, but when it fails, it can destroy a nation, said Gundersen.

Myths in the equations

The industry operates under a number of myths, said Gundersen. One such myth is that of a safe shutdown, he said.
While a shutdown ceases the nuclear chain reaction, the fuel continues producing about 5 percent of its original heat for another seven years, according to Gundersen. That 5 percent is the equivalent of about a quarter of a million horsepower.
The industry also assumes that water traps contain 99 percent of radioactivity from the core or spent fuel — unless, said Gundersen, the water happens to boil.
At Fukushima, the water boiled for five days, yet Japan still uses the 1-percent figure when analyzing the radioactivity of the crippled plant.
VY and Entergy operate under other myths when planning for evacuations, he said.
The company presumes a uniform evacuation zone, assuming that winds blow linearly, without considering landforms like mountains, he said. Such models also don’t consider how air moves in a river valley like the Connecticut River.

Fukushima and Chernobyl

Fukushima Daiichi’s release of nuclear contamination matched the amounts released by the 1986 Chernobyl disaster, said Gundersen. But at Chernobyl, the accident only exposed one reactor core.
Fukushima has four.
The Chernobyl plant had calmed in two weeks, while Fukushima has yet to calm. The plant has released about 10 times more radiation than Chernobyl’s, he said.
The releases from Fukushima include noble gases, which are fat-soluble and are absorbed through the lungs; radioactive iodine, which goes to the thyroid; cesium, a muscle seeker that can effect the heart muscles of children; and strontium 90, a radioactive isotope that is absorbed by the bones and can lead to leukemia.
People in Japan were exposed to a steady “rain” of this radiation for five days, said Gundersen.
Gundersen points to the Fukushima’s GE Mark 1 reactor design as the source of multiple physical flaws that perpetuated the March 2011 meltdown.
“[Fukushima] was an accident waiting to happen for 40 years,” said Gundersen.
The containment design was too small when the plant was constructed in the 1970s. After Three Mile Island, engineers added vents to Fukushima’s containment in case of a buildup of hydrogen gas.
Gundersen shook his head over the thought of installing vents in a structure designed for containment.
The vents lost power after the tsunami, requiring workers to open them manually by entering the highly radioactive containment area, said Gundersen. Workers had to turn the vent wheels an average of 300 turns to open the vents.
“How many more [plants] like this are out there?” he asked.
Additionally, Tokyo Electric Power Co. (TEPCO), the plant’s owner, knew for 20 years that the protective wall surrounding the plant was too low, Gundersen said.
The tsunami also knocked out the plant’s service water pumps, which pull ocean water into the plant to cool its core.
Even if the diesel generators had enough electricity to continue pumping inside the core, said Gundersen, the generators would have had no water to pump.
Another obstacle in responding to a nuclear meltdown is the creation of hydrogen.
According to Gundersen, without a cooling method, the nuclear fuel overheats. As the plant’s metal structure heats, it absorbs oxygen from the evaporating water, creating hydrogen. Pouring more water on the plant in an attempt to cool it inevitably increases hydrogen levels.
Luckily, he said, Fukushima only had seven years of spent nuclear fuel to manage during an accident.
Vermont Yankee stores spent fuel from more than 30 years of operation in its spent-fuel pool, suspended over the reactor. That material would be in the direct line of an explosion.

Lessons learned

Gundersen said he admires the workers at Fukushima who stayed at the damaged plant.
“They saved Japan and, likely, the world,” he said.
If the accident had happened on the weekend, then there would not have been enough of the plant’s crew to cope. Gundersen characterized using weekend “skeleton crews” at plants, VY included, as “crazy.”
It’s unlikely that a tsunami will surge up the Connecticut River and swamp Vermont Yankee, said Gundersen. “But we will get something [some day].”
Tsunami aside, Fukushima has cast a glaring light on the design inadequacies shared by VY, he said.
VY remains vulnerable to the loss of off-site power, as well as other issues, such as the Mark 1 reactor which stores spent fuel above the reactor, inadequate containment issues, and the vents in the containment structure.
The spent fuel at Fukushima stored outside the reactors in dry-cask storage would fare better than the fuel stored in the spent-fuel pool, said Gundersen. VY would do well to store more of its fuel in dry casks, but moving the fuel costs money, which eats into profits.
Gundersen said he hopes that we all learn from the Fukushima disaster, but that there is one bright spot — Japan now has the opportunity to shift from the old paradigm of nuclear power and become the first country that uses 21st-century technology and smart grids to move around its electricity.

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