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A Better Nuclear Power Plant?

Evening Edition

Above: Nuclear power is a hot topic these days, following the explosions at Fukushima, Japan last year, and problems at San Onofre that have shut down the plant. KPBS reporter Alison St John visited General Atomics on Sorrento Mesa, where researchers are looking for better ways to generate nuclear power. (Video by Katie Euphrat)

The San Onofre nuclear power station, located 50 miles north of San Diego was built in the 1980s, based on technology developed in the ‘60s. Its license runs out in 2022 and the operator, Southern California Edison, has not yet said if it will apply for an extension. Problems with the plant's new steam generators threaten to cost the company, and the ratepayer, dearly.

Aired 5/21/12 on KPBS News.

Nuclear power is a hot topic these days, following the explosions at Fukushima, Japan last year, and problems at San Onofre that have shut down the plant. General Atomics in Sorrento Mesa is looking for better ways to generate nuclear power.

At the sprawling General Atomics campus near Torrey Pines, Senior Vice President Dr John Parmentola said there are better ways to harness nuclear power.

“Several years ago,“ he said, “we set out to take a fresh look at nuclear, and asked ourselves, 'could we design a reactor that would be more economic?'”

John Parmentola, General Atomics
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Above: John Parmentola, General Atomics

Parmentola said the company is working on a new paradigm that would drive down the cost of nuclear power by 30 percent, and solve some of the safety issues that plague nuclear power today.

One of those safety issues is the amount of spent nuclear fuel stored on site. There are spent fuel rods stored in cooling pools at San Onofre, which are transferred to dry casks for long-term storage.

“The startling thing,” Parmentola said, “is the amount of energy that still exists in the waste at nuclear reactor sites around the country, as well as waste in the states of Kentucky and Ohio left over from enrichment. If you add up all that stuff, it’s 40 times the oil reserves of Saudi Arabia. It’s equivalent to 9 trillion barrels of oil in energy. It begs the question: ‘Can’t you do something with it ?’“

Many people have looked at this question. General Atomic’s answer is EM2. It’s a compact module containing a reactor that would run on spent fuel.

The lab where EM2 is being developed is in a low, unassuming building. Inside, there are furnaces and cylinders, computer screens, wires and more wires.

Christian Deck is part of the team working on the project. He’s developing a new kind of material to insulate the fuel rods. He proudly shows us the furnace where the ceramic composite is formed.

Christian Deck, researcher, General Atomics May 2012
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Above: Christian Deck, researcher, General Atomics May 2012

The ceramic “cladding,” or insulation, is particularly important, he explained, because this reactor is not refueled every 18 months like in current nuclear power plants. The fuel would stay in the reactor, burning, for 30 years.

“We need this material to safely contain the fuel throughout the entire life of the reactor,” Deck said, “under normal and under potential accident conditions.”

Parmentola believes this new insulation could have prevented the hydrogen explosion that happened at Fukushima when the fuel rods were exposed.

After several cycles of burning the nuclear fuel, Parmentola said the EM2 reactor could ultimately leave very little waste.

“The radioactivity of spent fuel can last hundreds of thousand of years,” he said. “The waste I’m talking about will last hundreds of years.”

One of the major objections to reactors that burn spent nuclear fuel has been the risk of proliferation. Parmentola said EM2 would generate material that could not be easily used by terrorists.

“These neutron absorbing products have no proliferation use whatsoever,“ he said. “Nobody would want to use them to make a bomb - you can’t make a bomb out of them.”

The EM2 modules -- including a reactor, a gas turbine and a heat removal unit -- are small. You would need about five of them to generate the same amount of energy produced by San Onofre. They are designed to fit on the bed of a flatbed truck to be shipped to wherever they are needed and buried underground.

Senior scientist, Robert Schleicher is the co-inventor of EM2. He admitted it could cost billions of dollars to build a prototype before bringing this new kind of nuclear fission reactor to the commercial market.

“EM2 is a very new idea,” he said, “and to take it from an idea to an actual working plant takes several thousand man years of work. This may take 20 years from where we are now to have an actually working plant.”

Murray Jennex, a systems engineer who used to work at San Onofre, took a look at General Atomic’s plans for EM2. Jennex is a believer in nuclear power, though after Fukushima he regularly took a Geiger counter to the beach in his home in Oceanside to check radiation levels.

Murray Jennex, former employee at San Onofre, currently SDSU associate professor,  specializing in knowledge management, system analysis and design.
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Above: Murray Jennex, former employee at San Onofre, currently SDSU associate professor, specializing in knowledge management, system analysis and design.

“I didn’t find anything,” he said.

Jennex thinks the idea of putting used fuel in this new type of reactor is a good one.

“If it works, it will be an excellent way of helping us solve some of the spent fuel problems,” he said.

But he’s not convinced the new design is as safe as General Atomics claims.

“This reactor is still subject to meltdowns,” he said.

Plus he is worried about the digital controls General Atomics proposes to use on the new design.

“We haven’t used digital because we have had trouble proving that they won’t fail,” Jennex said.

Digital controls are also vulnerable to cyber attack, he added.

“Anything that solves an old risk with new technology is introducing inherently new risks that we haven’t really thought through yet,” he concluded.

When dealing with nuclear power, Jennex said the technology must be tried and true. The problems with the newly designed steam generators at San Onofre are proving that point.

The challenge for General Atomics is to keep generating enough money to build prototypes to prove that EM2 technology is tried and true, cost-effective and safe. That will be billions of dollars.

Video by Katie Euphrat

Comments

Avatar image for user 'WhatTheFlux'

WhatTheFlux | May 21, 2012 at 8:02 a.m. ― 1 year, 10 months ago

Nuclear power isn’t the problem.

The problem is with the reactors the world has been using to make it. If the reactors at Fukushima had been Liquid Fluoride Thorium Reactors (LFTRs) they wouldn’t have a mess on their hands.

Liquid-fuel reactor technology was developed at Oak Ridge National Labs in the 1960s. Although the test reactor worked flawlessly for over 20,000 hours, the project was shelved, a victim of political shenanigans during the Nixon Administration.

A LFTR is a completely different kind of reactor, as different as an electric motor from a gasoline engine. It can’t melt down, and it automatically adjusts its heat generation to meet changing workload demands. It requires no active cooling system and can be installed anywhere on earth, even an underground vault. A tsunami or a tornado would roll right over it, like a truck over a manhole cover.

LFTRs use liquid fuel ⎯- nuclear material dissolved in molten fluoride salt. Solid-fuel reactors are atomic pressure cookers, with the constant danger of high-pressure ruptures, meltdowns, and the forceful ejection of radioactive material into the environment. LFTRs don’t use any water or steam, and they always operate at ambient pressure.

If disaster strikes and a LFTR springs a leak, the spill cools to an inert lump of rock, chemically locking all the nuclear material inside. The fuel can all be recovered and used again. The spill would be measured in square meters, not square kilometers.

LFTRs can deliver 750ºC heat for industrial processes, or spin a high-temperature gas turbine to generate power. They run on Thorium, a mildly radioactive material more common than tin and found all over the world. America has already mined enough Thorium to power the entire country for 400 years. It’s found by the ton in the tailings of our abandoned Rare Earth Element mines.

LFTRs are highly resistant to proliferation. Thorium is bred into 233Uranium inside the reactor, but only enough is made to keep the LFTR running, so no stockpiling occurs. While 233U is an excellent fuel, its harsh radiation makes it nearly impossible to steal, and extremely difficult to use in a weapon.

Liquid fuel can be continuously cleaned of the contaminants that spoil solid fuel. This unique feature enables LFTRs to consume their fuel so thoroughly that they can even use the spent fuel from other reactors, cleaning up our legacy of nuclear waste while producing a minuscule amount of waste themselves.

A 1-gigawatt LFTR, big enough to power a city of one million, will run on one ton of Thorium per year, or about 2 teaspoons per hour. The LFTR’s yearly long-term waste will be the size of a basketball. Compared to the long-term waste of a solid-fuel reactor, a LFTR’s waste would be substantially harmless in just 300 years. Not 300 centuries -- 300 years.

Google: LFTR, liquid fluoride thorium reactor, MSR, molten salt reactor, Thorium energy

See the Wired.Com article “Uranium Is So Last Century"

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Avatar image for user 'yotsubishi'

yotsubishi | May 24, 2012 at 8:38 a.m. ― 1 year, 10 months ago

The EM2 is just another re-incarnation of the helium-cooled fast neutron spectrum reactor. While this type of reactor has some attractive characteristics, safety is not one of them. The reactor must operate with very high power density with very little material that can absorb heat during an accident. As a result, the reactor has the meltdown characteristics of a birthday candle on the surface of the sun, and represents a substantially less safe alternative to modern commercial reactors that use water cooling. Every major nuclear country has rejected this type of reactor concept, in part because of its relatively poor safety characteristics.

Until recently, General Atomics was the industry champion of the world's safest reactor concept, a modular, helium-cooled thermal neutron spectrum reactor, sometimes referred to as a Modular Helium Reactor (MHR). In contrast to the EM2, this reactor concept has a large quantity of material in the core that absorbs heat and prevents the reactor fuel from reaching meltdown temperatures, even if all of the coolant is permanently lost. Unfortunately, the senior management at General Atomics abandoned the MHR in favor of EM2, and has stuck with this strategy even in the aftermath of the Fukushima accident.

Japan has the high temperature engineering test reactor (HTTR), which is an operational, engineering-scale prototype of the MHR. It has been used to demonstrate the intrinsic safety characteristics of the MHR.
Perhaps the events in Japan can lay the foundation for developing, demonstrating, and commercializing a next generation of nuclear power with intrinsic safety. International collaboration among the U.S., Japan, and other nations on the MHR would provide a relatively quick path for achieving this goal. More information on the HTTR is available at:

http://www.jaea.go.jp/04/o-arai/nhc/index.html

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