Saturday, February 26, 2011

Iran unloads fuel from Bushehr reactor

New York Times cites alarmist statements from U.S. nonproliferation experts

Fuel unloading at BushehrUpdated: Monday February 28, 2011

The New York Times reports that Iran's commercial Bushehr nuclear reactor is having problems with start-up. According to the newspaper, Iran told the IAEA last week it is planning to unload the fuel from the reactor core.

"Iran told atomic inspectors this week that it had run into a serious problem at a newly completed nuclear reactor that was supposed to start feeding electricity into the national grid this month, raising questions about whether the trouble was sabotage, a startup problem, or possibly the beginning of the project’s end."

This isn't the first time the reactor has had delays associated with fuel loading. Last August it was delayed by a leak in a cooling system associated with the central reactor. At least, that's what Iranian news sources said at the time. They later also blamed the Stuxnet computer worm, which is less likely as a reason for the delay.

The fact that the fuel is being removed from the reactor now could be an indication of a serious problem with the core or the cooling systems. It could also be a problem with the fuel itself.

In any case, with the fuel out of the reactor, the probability of an accident is vastly reduced since a critical chain reactor with the U-235 fissile material is no longer possible. This assumes the fuel is stored correctly once it is out of the reactor.

Was it Stuxnet?

There has been a lot of speculation that the Stuxnet computer worm might have infected the control system of the reactor. This doesn't make much sense given what we now know about it.

cybersecurityThe computer code in the Stuxnet work appears to have another purpose altogether, and that is to disable the centrifuges in Iran's uranium enrichment plants. The worm attacks the programmable logic controllers (PLC) of the centrifuges forcing them to spin at irregular speeds and subsequently to failure.

It is less likely that the Stuxnet worm is affecting the Bushehr reactor because it targets a specific PLC. Only if any of the targeted PLCs are used on devices in the reactor, such as cooling pumps or components related to control rod drive mechanisms, then there could be a problem based on the Stuxnet worm.

What is the Bushehr reactor?

The Bushehr reactor is a Russian-built VVER light water design (image) with 163 fuel assemblies of low enriched uranium. Iran began building the Bushehr reactor in 1975. It was one of two planned units. Work on both units ground to a halt during the 1979 revolution.

Russia picked up the pieces of one of the reactors 16 years later. Progress has been delayed repeatedly by disputes between Iran's mercurial and fragmented government and Russia's industrial export engine that runs on hard currency. At one point work stopped when Iran made a progress payment in euros and the Russians demanded dollars.

The VVER reactor is a conventional light water design widely used in Russia and eastern Europe. The Energy Information Administration at the U.S. Department of Energy notes that the Russian Federation continues to build VVER units.

VVER fuel assemblyAccording to TVEL, the Russian nuclear fuel manufacturer, a VVER-1000 requires 163 fuel assemblies in a hexagon shape with 306 fuel rods in each assembly. Uranium is enriched to 4.8 percent U-235. (photo right)

Fuel rods for VVER reactors have zirconium-alloy claddings that are filled with fuel pellets of uranium dioxide. Some fuel rods, six-to-nine per assembly, are filled with pellets containing gadolinium oxide. Each fuel assembly has 435 kg (935 lbs) of uranium. The VVER reactor is a PWR with an outlet temperature of 320 degrees C.

Chernobyl type accident not possible

The VVER reactor is not the same design at the one that was destroyed at Chernobyl. The Russians have a huge image problem from the Soviet-era disaster at Chernobyl 4, an RBMK water cooled graphite moderated reactor. The Russians are not building any more RBMKs thought several remain in service. (Photo tour of Smolensk RBMKs)

The new VVER units conform to international standards and have developed an export market. The new VVER design has an estimated operational life of at least 30 years. Russia is building four in India with plans for 18 and recently inked a deal to build two for Vietnam.

cuckoo clockThis is why alarmist statements by two people who should know better are out of place in the newspaper's report. Their comments are not credible and suggest the warning of a cuckoo clock rather than one that should be taken seriously by the West.

"David Albright, president of the Institute for Science and International Security, a private group in Washington that tracks nuclear proliferation, said of the problem behind the Bushehr upset.

“It raises questions of whether Iran can operate a modern nuclear reactor safely,” he added. “The stakes are very high. You can have a Chernobyl-style accident with this kind of reactor, and there’s lots of questions about that possibility in the region.”

Here’s the problem with this statement . . .

You cannot have a "Chernobyl type" accident with the Bushehr reactor because it is not a graphite core design. Further, if the fuel is safely removed from the core, then there can't be a runaway chain reaction resulting in a melt down from heat.

Mixing Maples and Oranges

The New York Times goes further in its hunt for alarmist statements. It cites the remarkable David Lochbaum from the anti-nuclear group Union of Concerned Scientists (UCS). Like a cuckcoo clock, he frequently sounds off about safety issues often blowing them out of proportion relative to the risk. (See Idaho Samizdat “Crying wolf at the UCS, August 28, 2010.)

Insofar as his statement to the New York Times is concerned, he makes a sweeping prognostication, but is it supported by the facts?

“It could be simple and embarrassing all the way to ‘game over,’ ” said David A. Lochbaum, a nuclear engineer at the Union of Concerned Scientists

To make his point he cites the troubled Maple Reactors in Canada which bear little resemblance to the Russian VVER. The two AECL units were R&D projects designed to replace the aging isotope production reactor at Chalk River, Ontario. The project to build the replacements was ended in May 2008 by the government following a string of technical failures and significant cost overruns.

While it may be that Iran is a county that can’t properly manage a commercial nuclear reactor, citing the failed Maple reactor project isn’t a useful way to make that point.

OK, so what's wrong with Iran's reactor?

People in the nuclear industry with knowledge of the Bushehr reactor have suggested there are several reasons why the fuel was pulled from the core.

  • Dirt in the fuel assemblies. It is a desert environment. Poor HVAC filters in the plant or exposure to dust and dirt during shipment could account for it. Construction debris might still be at the bottom of the reactor core.
  • Problems with the cooling system especially the primary loop. Bushehr is a PWR design which means heat transfer to the steam turbines takes place with a secondary loop outside the reactor. The Russians built the reactor, but the steam system and turbines came from Siemens. The Stuxnet virus attacks Siemens programmable logic controllers (PLCs).
  • Problems with control rod drive mechanisms. The control rods moderate (control) the fission process in the reactor. If they also rely on Siemens PLCs, then they are vulnerable to disruptions of the distributed control system.
  • Irregularities in reactor performance once a chain reaction was achieved after fuel load.
Update 28 Feb 2011: Reuters reports a broken pump in the emergency cooling system is the reason Iran is removing the fuel from the Bushehr reactor.

"Mark Hibbs, a senior associate in the Nuclear Policy Program of the Carnegie Endowment for International Peace, said that if it was a broken pump that was the problem, small bits of metal in the cooling water could damage the fuel rods.

"If that happens, radioactive gases can escape from the fuel and into the coolant," Hibbs said. "There has to be a cause analysis there to find out why the equipment failed."

Iran’s nuclear weapons program

The Bushehr reactor isn’t the problem with Iran, a fact that even U.S. Secretary of State Hillary Clinton notes in her speeches. The reason is the Russians are supplying conventional nuclear fuel and will take back the spent fuel.

The plutonium in the spent fuel is an unlikely proliferation risk as Iran has no fuel reprocessing facilities. Further, reactor grade plutonium is only about 50% Pu-239. The cost and complexity of the technologies required to purify reactor grade to weapons grade makes it impractical for use in nuclear weapons.

The problem is that Iran is developing two capabilities. The first is to be able to make highly enriched uranium at at least 85% U235 to be able to construct a uranium based nuclear weapon, and second to mount it on a medium range missile, one able to hit a target 1,200 miles away.

So far Iran has only enriched uranium to just under 20%, which is the threshold for HEU. This is a political signal that it plans to go beyond that boundary as part of an effort to gain political influence in the Middle East.

Iran’s claims that it is enriching uranium to that level is nonsense because it rejects offers for reliable fuel services for its medical isotope reactor. If Iran givens up its inventory of enriched uranium, it no longer has the bogey man of potentially building nuclear weapons with which to threaten its neighbors.

So far Iran has steadfastly maintained a course aimed at building nuclear weapons. It has stiff-armed the IAEA efforts to inspect its facilities. Taken together with its wacko political leadership, it makes Iran a major headache for the U.N. Security Council.

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Thursday, February 24, 2011

Can NNSA deliver on mixed oxide fuel?

Three utilities are interested, but production may fall short of demand

A very big "if" in the equation to measure the potential success of NNSA's MOX $4.6 billion MOX fuel plant being built in South Carolina is whether the fuel can be delivered to customers when they need it.

The "when" is the schedule of reactor fuel outages for each customer. These schedules line up with the regularity, and inflexibility, of planets in their annual orbits around the sun. Once they pass a certain point in time, that's it. Reactor outages have the finality of empty seats in commercial airplanes after they take off. The air carrier cannot fill them once the jet is in the air.

Utilities interest v. potential supply

Duke Energy, the Tennessee Valley Authority (TVA), and Energy Northwest are evaluating the pros-and-cons of using MOX at three separate nuclear power stations.

FCW_logo_smallIn my coverage this week in Fuel Cycle Week (V10;N413 2/24/11), I report that two of the three commercial nuclear utilities considering the use of MOX in their reactors tell FCW the issue of reliable fuel services is one of the most important items that must be addressed in any fuel supply contract with Shaw-Areva MOX Services.

However, inconsistencies abound about how important this issue really is to the utilities involved and who has the responsibility for pulling all the pieces together.

Even more interesting is that if all seven reactors that are potential users of MOX fuel place orders for it, NNSA may not have enough capacity to produce the required combination of PWR and BWR fuel assemblies.

Who will be accountable for reliable fuel services may turn out to be as important an issue for MOX fuel as the capability to use it in the first place.

Read the full story exclusively at the Fuel Cycle Week blog online now.

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Tuesday, February 22, 2011

Spain scraps phase out of nuclear energy

Government renews three of eight reactors for another ten years

power linesA long-standing Spanish government policy of phasing out the nation's 7.5 GWe of nuclear powered electricity (18% of total electricity) is being reversed both in the form of new policy and in renewal of the operating licenses for three of the nation's eight nuclear reactors.

Spain's Congress last week ratified new legislation that means the reactors can operate for longer than 40 years.

The moves are a complete turnaround from a prior government policy of phasing out the nation's nuclear plants. Most public opinion about nuclear energy is negative and neither political party has supported reactor life extension until now.

Spain's electric grid is almost completely isolated from the rest of Europe which makes energy security a leading factor in the government's decision to keep the reactors running past the artificial 40-year deadline. The financial collapse of its solar energy subsidy program may also have played a role in the change of heart.

Read the full story at CoolHandNuke, a nuclear energy jobs portal and a whole lot more.


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Sunday, February 20, 2011

Spent nuclear fuel is actually full of energy

Former NRC official says the time has come revive long-dormant reprocessing program

NRC INTERVIEWFailure to pursue a program for recycling spent nuclear fuel has put the U.S. far behind other countries. It represents a missed opportunity to enhance the nation's energy security and influence other countries.

These themes are the heart of a talk by Dale Klein, Ph.D., (left) the former chairman of the Nuclear Regulatory Commission (NRC) given Sunday, Feb 20 at a session of the AAAS annual meeting being held in Washington, DC.

Dale Klein, who is now Associate Vice Chancellor for Research at the University of Texas System, said largely unfounded concerns and "long-held myths" about the reprocessing of spent fuel have prevented the U.S. from tapping into an extremely valuable resource.

Spent nuclear fuel, which includes some plutonium, often is inaccurately referred to as waste, Klein said.

"It is not waste," he said. "The waste is in our failure to tap into this valuable and abundant domestic source of clean energy in a systematic way. That's something we can ill-afford to do."

Energy density matters

DensityComparisonCompared to other fuels used in the production of electricity, the energy density of uranium is remarkable,

Klein said, noting that 95 percent of the energy value in a bundle of spent nuclear fuel rods remains available to be re-used.

"The once-through nuclear fuel cycle, which is our practice in the U.S., is an enormous waste of potential energy," he said.

Critics cite the potential for nuclear weapons proliferation as the biggest reason to oppose recycling. But such concerns are largely unfounded, Klein said.

"While it is true that the plutonium in recycled nuclear fuel is fissionable, no country in the world has ever made a nuclear weapon out of low-grade plutonium from recycled high burn-up nuclear fuel," he said. "It just doesn't work for a strategic or a tactical nuclear weapon."

U.S. is on the sidelines

While the U.S. has sat on the sidelines, other countries, including France, Japan, the United Kingdom, Russia, India, and China have dedicated significant resources toward their reprocessing programs, Klein added.

"U.S. leadership in this area has been lost, and the underlying technological capability and intellectual capital needed to compete internationally have diminished to near irrelevance."

Reprocessing not only recovers significant energy value from spent fuel, it substantially reduces the volume and radiotoxicity of high-level nuclear waste.

Spent fuel is safely stored in dry casks

Today, U.S. utilities operating nuclear power plants continue to store spent nuclear fuel rods on site in pools of water, before eventually moving them to dry cask storage. And while there is some debate over whether the casks should be located in one central storage site, the practice is widely accepted as safe and secure.

"That's another myth – that we don't know how to safely store nuclear spent fuel," Klein said.

Public-private partnership need for reprocessing

partnersEstablishing a program to recycle nuclear fuel will require a public-private partnership that operates outside normal Congressional appropriations and has a mandate to manage the fuel over a period of decades, he asserted.

The government's Blue Ribbon Commission, chartered by the Department of Energy, is charged with making recommendations for the safe, long-term management of spent fuel. The 15-member commission is to issue a draft report this summer, with a final report to be completed in January 2012.

"At a time when we are seeking ways to limit carbon emissions from the generation of electricity, the recycling of spent nuclear fuel would appear to be a particularly good fit."

The full text of Klein’s talk is available from AAAS as part of the conference proceedings.

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