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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Bill Rodgers said...

The NY Times article also lists Mr. Lochbaum as a former official at the NRC. I looked at his public resume both on the UCS site and another seperate resume he submitted for a workshop in California as well as testimony he provided a subcomittee on global warming

None of those 3 publicaly available documents state he worked at the NRC. His work experience appears to be more a contract engineer doing outage type of jobs since he has a laundry list of plants on his resume until he started at the UCS.

Just wondering if you knew? If Mr. Lochbaum did not work at the NRC or if his work was not as an "official" then this is another factual error on the part of the NYT reporter. In this case the error would then make it appear Mr. Lochbaum has more gravitas then he should.

Thanks and good article pointing out the usual fear mongering on the part of the UCS that adds nothing to the real discussion.

Al S. said...

The security consultant Ralph Langner has written several posts on the Stuxnet worm. He states that the Stuxnet worm was also tageted at Bushehr, and could destroy the steam turbines there.
This would not be likely to damage the reactor, but would make it useless for electricity production for some time.

Anonymous said...

There is another more sinister interpretation of startup problems. I think I read somewhere that the difference between high weapons quality plutonium and low weapons quality was the time spent in the reactor. Could it be that a rod used for an month could be diverted for weapons grade plutonium extraction but a rod left for a year would not be as attractive for extraction? It that is the case I would run the reactor for a month and have a problem.

Sanatanan said...

Pardon me for a minor nitpick -- I think you may have meant "burnable poison" rather than "moderate neutrons" in the context of use of Gadolinium. More apologies, if I happen to be wrong.

It occurs to me that the fuel rods may have had to be removed from the reactor in order to search, reach and remove any loose parts that may have been left inadvertently at the bottom of the core in spite of all the care usually taken during fuel loading. Is there a system incorporated in the VVER design that monitors for loose parts in the core, which may then have triggered the warning?

Lorne Marr said...

Bushehr was originally scheduled to come on stream in July 1999 but the start-up has been delayed repeatedly by construction and supply glitches. Now, more than 12 years later, Iran is having problems with it again. How is it going to handle more serious problems once they get the plant going? The probability of an accident is just too high and the world has a reason to be worried.

Anonymous said...

To Bill Rogers. Lochbaum did indeed work briefly at the NRC's Chattanooga offices and recently returned to UCS.

Anonymous said...

Mr. Lochbaum was never an NRC "official." As stated above, he was hired as an instructor for about a year at the NRC's technical training center in Chatanooga, far removed from any type of decision making capacity one would assume woukd be attendant to being an agency official. Of course, now everytime he is quoted by the media, he has somehow become an "official."

Bill Rodgers said...

I appreciate the correction on Mr. Lochbaum's work history.

However as one individual responded, an instructor is in no way a decision making position within the NRC. Additionally, many engineers in the nuclear industry could post similar resumes as Mr. Lochbaum's with the exception being the path his career took leading him to work for UCS. Therefore the NYT article should issue a correction on Mr. Lochbaum's resume and job functions to ensure a proper weight is given to his comments by the average reader.

As I posted on a seperate forum, the Iranian issue is very sensitive issue. Publicly indicating Mr. Lochbaum as an "official" within the NRC could lead the average reader to come to a conclusion the NRC may be weighing in the Iranian reactor issues when no such thing has happened nor ever will. It has become very common in the politics of D.C. to use former or retired officials to speak in an unofficial capacity but with insider information provided to them.

Considering its prominent placement in the print edition on page A4, the article should be 100% accurate and should not have included what were basically throw-away comments from known anti-nuclear parties. What value did Mr. Lochbaum's comments add to the article? None that I see other then to ensure UCS once again received free PR.


I've exposed some glaring technical gaffes on Mr. Lochbaum's part at:

It seems the need to keep writing alarmist boilerplate has made him sloppy.