Tag Archives: IAEA

Sitting Still Nuclear Waste

Several options are available to immobilise waste resulting from nuclear fuel reprocessing. One of these is vitrification – a mature technology which has been used for high-level nuclear waste immobilization for over 50 years…Argentina is considering vitrification as a viable option for dealing with its high-level nuclear waste. The Argentine National Programme for Radioactive Waste Management aims to build capacities to implement vitrification processes for radioactive waste….
The vitrified radioactive waste is extremely durable, and ensures a high degree of environmental protection. Although the process of vitrification requires a high initial investment and then operational costs, waste vitrification has important advantages: it significantly reduces the volume of waste, and allows simple and cheap disposal possibilities. The overall cost of vitrified radioactive waste is usually lower than alternative options when transportation and disposal expenses are taken into account. For this reason, the process is very attractive for sates seeking effective and reliable immobilisation solutions for their radioactive waste stocks.

Excerpts from Taking a Closer Look at Vitrification: How the IAEA Helps Countries Utilise Advanced Immobilisation Technologies, IAEA Press Release, Mar. 24, 2017

Stolen Nuclear Material Iraq

industrial radioagraphy camera. image from GAO

Iraq is searching for “highly dangerous” radioactive material stolen in 2015, according to an environment ministry document and seven security, environmental and provincial officials who fear it could be used as a weapon if acquired by Islamic State.

The material, stored in a protective case the size of a laptop computer, went missing in November 2015 from a storage facility near the southern city of Basra belonging to U.S. oilfield services company Weatherford WFT.N, the document seen by Reuters showed and officials confirmed…

The material, which uses gamma rays to test flaws in materials used for oil and gas pipelines in a process called industrial gamma radiography, is owned by Istanbul-based SGS Turkey, according to the document and officials.  A U.S. official said separately that Iraq had reported a missing specialized camera containing highly radioactive Iridium-192 to the International Atomic Energy Agency (IAEA), the Vienna-based U.N. nuclear watchdog, in November 2015….The environment ministry document, dated Nov. 30 and addressed to the ministry’s Centre for Prevention of Radiation, describes “the theft of a highly dangerous radioactive source of Ir-192 with highly radioactive activity belonging to SGS from a depot belonging to Weatherford in the Rafidhia area of Basra province”…

A senior environment ministry official based in Basra, who declined to be named as he is not authorised to speak publicly, told Reuters the device contained up to 10 grams (0.35 ounces) of Ir-192 “capsules”, a radioactive isotope of iridium also used to treat cancer.

The material is classed as a Category 2 radioactive source by the IAEA, meaning that if not managed properly it could cause permanent injury to a person in close proximity to it for minutes or hours, and could be fatal to someone exposed for a period of hours to days….

Large quantities of Ir-192 have gone missing before in the United States, Britain and other countries, stoking fears among security officials that it could be used to make a dirty bomb…..“They could simply attach it to explosives to make a dirty bomb,” said the official, who works at the interior ministry…But the official said the initial inquiry suggested the perpetrators had specific knowledge of the material and the facility. “No broken locks, no smashed doors and no evidence of forced entry,” he said….

Besides the risk of a dirty bomb, the radioactive material could cause harm simply by being left exposed in a public place for several days, said David Albright, a physicist and president of the Washington-based Institute for Science and International Security…The senior environmental official said authorities were worried that whoever stole the material would mishandle it, leading to radioactive pollution of “catastrophic proportions”.

Excerpts from Exclusive: Radioactive material stolen in Iraq raises security fears, Reuters, Feb. 17, 2016

See also Nuclear Materials in Iraq and the 2014 Civil War

 

Nuclear Accidents of the Future: the preparations

anti-nuclear_protests_in_Tokyo

Three major atomic accidents [Three Mile Island US 1979, Chernobyl USSR 1986, Fukushima Japan 2011] in 35 years are forcing the world’s nuclear industry to stop imagining it can prevent more catastrophes and to focus instead on how to contain them.  As countries such as China and India embrace atomic power even after the Fukushima reactor meltdowns in 2011 caused mass evacuations because of radiation fallout, scientists warn the next nuclear accident is waiting to happen and could be in a country with little experience to deal with it.

“The cold truth is that, no matter what you do on the technological improvements side, accidents will occur — somewhere, someplace,” said Joonhong Ahn, a professor at the Department of Nuclear Engineering of University of California, Berkeley. The consequences of radiation release, contamination and evacuation of people is “clear and obvious,” Ahn said. That means governments and citizens should be prepared, not just nuclear utilities, he said.

While atomic power has fallen from favor in some western European countries since the Fukushima accident — Germany, for example, is shutting all of its nuclear plants — it’s gaining more traction in Asia as an alternative to coal. China has 28 reactors under construction, while Russia, India, and South Korea are building 21 more, according to the World Nuclear Association. Of the 176 reactors planned, 86 are in nations that had no nuclear plants 20 years ago, WNA data show…

The problem is that the causes of the three events followed no pattern, and the inability to immediately contain them escalated the episodes into global disasters with huge economic, environmental and political consequences. Even if no deaths have yet been officially linked to Fukushima radiation, for example, cleanup costs have soared to an estimated $196 billion and could take more than four decades to complete.

If nuclear is to remain a part of the world’s energy supply, the industry must come up with solutions to make sure contamination — and all other consequences — do not spread beyond station grounds, Gregory Jaczko, ex-chairman of the U.S. Nuclear Regulatory Commission, said in an interview in Tokyo….

Since the introduction of nuclear stations in the 1950s, the industry has focused safety efforts on design and planning. Research and innovation has looked at back-up systems, passive technology that would react even if no human operator did, and strengthened materials used in construction of atomic stations….

The official toll from the reactor explosion at Chernobyl was put at 31 deaths. Radiation clean-up work, however, involved about 600,000 people, while 200,000 locals had to be relocated.  The accident contaminated 150,000 kilometers of land and according to the last Soviet leader Mikhail Gorbachev it was a factor in bringing about the collapse of the Soviet Union in 1991.

In Japan, the meltdown of three Fukushima reactors helped unseat premier Naoto Kan and forced the evacuation of about 160,000 people, destroying local fishing, farming and tourism industries along the way. It also brought tens of thousands of anti-nuclear protesters out onto the streets in the country’s biggest demonstrations since the 1960s. Tokyo Electric Power Co., the plant operator and once the world’s biggest non-state power producer, would have been bankrupted by the Fukushima accident but for billions of dollars in government aid…

Building a plant that would contain an accident within the facility boils down to cold cash, he said.  The review calls for new reactor designs to make a major release of radioactive fallout outside the station site “practically impossible,” the IAEA said. The standard would be “crucial for public acceptance and for the sustainability of nuclear energy.” Specialists on the review met for the first time in March and no conclusions are yet available, IAEA spokesman Greg Webb said by e-mail.

The problem with an engineering solution, an ever better reactor design or grander safety systems, is that based on the premise that all technology is fallible those defense systems can also fail, Berkley’s Ahn said.  “This is an endless cycle,” Ahn said. “Whatever is your technology, however it is developed, we always have residual risk.”  When the next nuclear accident occurs the world needs to have better knowledge of how to limit the spread of radiation and do the clean-up, including removing radiation from the soil, water and having an efficient evacuation drill for the population in danger zones, Ahn said. We also need more understanding of the impact of low-dose radiation on organisms, he said.  “This is about recovery from an accident, not preventing an accident,” Ahn said. “It’s completely different. And I think this concept is very necessary for the future of nuclear utilization.”

Excerpts from Yuriy Humber, World Needs to Get Ready for the Next Nuclear Plant Accident, Bloomberg, Apr. 4, 2014

The Benefits of Being a Threshold Nuclear Power: Japan v. China

japan nucler fuel limited logo

China has urged Japan to return over 300 kilograms of weapons grade plutonium to the Unites States and to explain how it intends to resolve its surplus plutonium problem. At a regular press briefing in Beijing on 17 February 2014, and in response to a question on Japan’s plutonium stocks, a Foreign Ministry spokeswoman stated:

“China attaches great importance to nuclear proliferation risks and potential threats posed by nuclear materials to regional security. China has grave concerns over Japan’s possession of weapons-grade nuclear materials… Japan’s failure to hand back its stored weapons-grade nuclear materials to the relevant country has ignited concerns of the international community including China.”

As reported in January 2014, agreement has been reached between the United States and Japan for the return of plutonium used in the Fast Critical Assembly (FCA) in JAERI Tokai Research Establishment, Tokai-mura, Ibaraki Prefecture. The formal agreement is expected to be concluded at the Nuclear Security Summit in the Netherlands in March 2014. In its latest declaration to the International Atomic Energy Agency (IAEA) and in its 2012 plutonium management report Japan stated that the FCA facility has the total of 331 kg of plutonium, of which 293 kg is fissile plutonium. The largest share of this plutonium was supplied by the United Kingdom in addition to that supplied by the United States.

Commenting further, the Chinese Foreign Ministry declared:

“China believes that Japan, as a party to the Treaty on the Non-Proliferation of Nuclear Weapons, should strictly observe its international obligations of nuclear non-proliferation and nuclear security. The IAEA requires all parties to maintain a best possible balance of supply and demand of nuclear materials as contained in the Guidelines for the Management of Plutonium. Japan’s large stockpile of nuclear materials including weapons-grade materials on its territory is an issue concerning nuclear material security, proliferation risks and big supply-demand imbalance.”

In addition to the call for the return of the weapon’s grade plutonium, the Chinese statement also raises a question over Japanese fuel cycle policy and its inability to use its existing plutonium stocks. With all 48 nuclear power reactors shutdown there is currently no demand for its separated plutonium as mixed oxide (MOX) fuel. However, Japanese policy continues to plan the commercial operation of the Rokkasho-mura reprocessing plant as early as October 2014, following a safety assessment by the Nuclear Regulatory Authority (NRA). In its latest declaration to the IAEA, Japan’s Atomic Energy Commission reported that as of 31 December 2012, Japan held 44,241 kg of separated unirradiated plutonium, of which 9,295 kg was stored in Japan and 34,946 kg was stored abroad. Japan’s plutonium program, its challenges and alternatives was recently addressed at a Tokyo symposium and in detailed analysis by IPFM.

As yet, there has been no official response from the Japanese government to the Chinese Foreign Ministry statement, which has been extensively reported through Chinese media outlets

By Shaun Burnie with Mycle Schneider, China calls on Japan to return weapons grade plutonium to the United States, International Panel on Fissile Materials, Feb 18, 2014

Trapping the Dirty Bomb: 2013 state-of-the-art

Passport NetS2 SmartShield.  Image from Passport Systems Inc.

Nuclear and radiological materials slipped out of regulatory control 2,331 times between 1995 and the start of this year, according to the Incident and Trafficking Database compiled by the International Atomic Energy Agency (IAEA). The materials are widely used in industry, agriculture and medicine. They are kept in many poorly guarded X-ray and cancer-treatment clinics. Such places are often not overseen with terrorism in mind. They have even been bought by crooks as front operations, says Rajiv Nayan, of India’s Institute for Defence Studies and Analyses. Raids on abandoned uranium mines in the Democratic Republic of Congo are more frequent, according to that country’s General Atomic-Energy Commission. The problem is most acute in the former Soviet Union: in Ukraine alone, roughly 2,500 organisations use radiological materials.

In Georgia a counter-trafficking unit set up by the interior ministry seven years ago has arrested two or three teams smuggling radiological material every year save 2009. The lure of profits is so strong that some ex-cons get back into the business, says Archil Pavlenishvili, leader of the unit. Interpol has said such trafficking is growing: an acute “real threat to global security”.  It all sounds scary enough. But the reality has been less so. Moreover, by many accounts the most plausible dangers appear to be declining.

For a start, an “overwhelming” number of buyers turn out to be undercover cops, says Mark Hibbs of the Carnegie Endowment for International Peace, a think-tank. A sizeable network of informers helps Georgia’s interior ministry to keep a close eye on the four or five cells in the country currently trying to obtain or sell radiological material, says Mr Pavlenishvili. ..Beyond this, intelligence agencies are hunting down traffickers with help from special “link analysis” computer programs. Also known as “network analysis” software, this crunches data from numerous sources to identify people whose travel, purchases, web searches, communications, schooling and so forth may spell trouble—perhaps an employee in radiation therapy who begins frequenting an inconveniently located bar whose owner receives phone calls from a drug-runner with growing operations.

Half a dozen Western governments “pay huge amounts of attention” to this, says an executive at a developer of the software. At least one spy agency in America, Australia, Britain, Canada, New Zealand, and an unnamed European country pays more than $1m a month to use it. The counter-trafficking units in both Georgia and Romania note that link-analysis software made by i2, owned by the giant IBM computer company, has helped to nab traffickers. Atsuko Nishigaki, the unit’s boss, says Japan’s economy ministry employs ten analysts to use a competitor’s software to identify traffickers in nuclear or radiological material.

America’s National Nuclear Security Administration has sponsored the installation of radiation-detection kit at ports in 23 countries and counting. The Megaports Initiative, as it is called, aims to have half of the world’s maritime container cargo routinely scanned by 2015. Networked systems are also being developed with detectors small enough to be worn on a police officer’s belt. The idea is to relay data on potentially dangerous radiation through a mobile-phone network to a central computer. Knowing each device’s location and the strength of the radiation it detects, the computer can “triangulate” the source’s approximate location.

Difficult problems remain. False alarms triggered by anything from a pallet of cat litter to radiation-therapy patients and nuclear-power-plant shipments have slowed research and development on one such network at the Lawrence Livermore National Laboratory in California, says Simon Labov, a co-ordinator there. Even so, the lab’s work continues to be financed by America’s defence, energy and homeland-security departments. In October 2013 the latter’s Domestic Nuclear Detection Office asked for proposals for a similar system, dubbed Human Portable Tripwire. Other outfits that have developed technology for such schemes include Smiths Detection in Britain and, in America, Berkeley Nucleonics, General Electric, GENTAG, Passport Systems and Purdue University.

The sheer danger of making a dirty bomb is a factor too. Without the right equipment and expertise, the really nasty stuff can kill the maker of a bomb before it is ready—part of the reason, perhaps, that no spectacular dirty-bomb attack has yet been launched. F

Dirty Bombs: Glowing in the dark, Economist, Dec. 14, 2013, at 67

Nuclear Renaissance on Track Despite Fukushima

According to a 2012 OECD/NEA and IAEA report: Although the Fukushima Daiichi nuclear accident has affected nuclear power projects and policies in some countries, nuclear power remains a key part of the global energy mix. Several governments have plans for new nuclear power plant construction, with the strongest expansion expected in China, India, the Republic of Korea and the Russian Federation. The speed and magnitude of growth in generating capacity elsewhere is still to be determined.

By the year 2035, according to the joint NEA-IAEA Secretariat, world nuclear electricity generating capacity is projected to grow from 375 GWe net (at the end of 2010) to between 540 GWe net in the low demand case and 746 GWe net in the high demand case, increases of 44% and 99% respectively. Accordingly, world annual reactor-related uranium requirements are projected to rise from 63 875 tonnes of uranium metal (tU) at the end of 2010 to between 98 000 tU and 136 000 tU by 2035. The currently defined uranium resource base is more than adequate to meet high-case requirements through 2035 and well into the foreseeable future.

Although ample resources are available, meeting projected demand will require timely investments in uranium production facilities. This is because of the long lead times (typically in the order of ten years or more in most producing countries) required to develop production facilities that can turn resources into refined uranium ready for nuclear fuel production.

With uranium production ready to expand to new countries, efforts are being made to develop transparent and well-regulated operations similar to those used elsewhere to minimise potential environmental and local health impacts….

Excerpt, Uranium 2011: Resources, Production and Demand A Joint Report by the OECD Nuclear Energy Agency and the International Atomic Energy Agency, OECD, 2012

Iran’s Nuclear Program, is a breakthrough possible?

The head of a U.N. nuclear team traveling to Iran on Saturday (Jan 28, 2012) urged the country to work with his mission on probing Tehran’s alleged attempts to develop an atomic arms program, adding such cooperation is long overdue.The unusually blunt comments by International Atomic Energy Deputy Director General Herman Nackaerts reflected the importance the IAEA is attaching to the chief focus of the trip — ending more than three years of Iranian refusal to answer questions about such suspicions.

Diplomats said Iran had accepted the inclusion of two senior weapons experts — Jacques Baute of France and Neville Whiting of South Africa — with relatively little fuss. That suggests the Islamic Republic may be prepared to address some issues related to the allegations.  Also on the team is Rafael Grossi, IAEA chief Yukiya Amano’s right-hand man.  Any progress would be significant…Iran says it is enriching only to generate energy. But it has also started producing uranium at a higher level than its main stockpile — a move that would jump-start the creation of highly enriched, weapons-grade uranium, should it chose to go that route. And it is moving its higher-enriched operation into an underground bunker that it says is safe from attack.

Excerpt, UN nuclear team hopes for progess on probing alleged Iranian arms program, Associated Press, January 28, 2012

Iranian Nuclear Program: turning the screws on

The U.N. atomic agency plans to reveal intelligence next week suggesting Iran made computer models of a nuclear warhead and other previously undisclosed details on alleged secret work by Tehran on nuclear arms, diplomats told The Associated Press.  Other new confidential information the International Atomic Energy Agency plans to share with its 35 board members will include satellite imagery of what the IAEA believes is a large steel container used for nuclear arms-related high explosives tests, the diplomats said.

The agency has previously listed activities it says indicate possible secret nuclear weapons work by Iran, which has been under IAEA perusal for nearly a decade over suspicions that it might be interested in develop such arms.  But the newest compilation of suspected weapons-related work is significant in substance and scope. The diplomats say they will reveal suspicions that have not been previously made public and greatly expand on alleged weapons-related experiments that have been published in previous reports on Iran’s nuclear activities.  It also comes as the drumbeat of reports about possible military action against Iran’s nuclear facilities intensifies.

Israeli President Shimon Peres said Friday that international community is closer to pursuing a military solution to the standoff over Iran’s nuclear program than a diplomatic one. The comments, from a known dove, assumed added significance because they followed unsubstantiated reports that Prime Minister Benjamin Netanyahu was seeking his government’s support for a strike against Tehran.  British media have separately cited unnamed British officials as saying London was prepared to offer military support to any U.S. strike on Iran’s nuclear facilities.  In Vienna, the diplomats — from IAEA member nations — asked for anonymity because their information was privileged. One of th said the material drawn up by IAEA chief Yukiya Amano will be in an annex running around 12 pages and attached to the latest of a regular series of agency reports on Iran’s nuclear enrichment program and other activities that could be used to arm nuclear missiles.  Previously undisclosed information contained in the annex, said the diplomats, will include:

— Intelligence from unnamed member states that a bus-sized steel container, located at the Iranian military base of Parchin is likely being used for nuclear-related high explosives testing of the kind needed to release an atomic blast. The agency has satellite imagery of the container.

— Expanded evidence that Iranian engineers worked on computer models of nuclear payloads for missiles.

Significantly, said the diplomats, these alleged experiments took place after 2003 — the year that Iran was believed to have stopped secret work on nuclear weapons, according to a 2007 U.S. intelligence assessment. But diplomats have told the AP that Tehran continued arms-related experiments in a less concentrated way after that date, a view reflected by recent IAEA reports that have detailed suspicions that such work may be continuing up to the present.

The annex will also say that more than 10 nations have supplied intelligence suggesting Iran is secretly developing components of a nuclear arms program — among them an implosion-type warhead that it wants to mount on a ballistic missile.

It says that two foreign “sources” — apparently countries or nongovernment groups within countries — have helped Iran develop a weapons design, without naming them. And it details how Iran bought “dual use” — peaceful or military — nuclear technology from the black market network of renegade Pakistani scientist A. Q. Khan, as well as alleged preparations for a nuclear weapons test.

The upcoming report is meant to ratchet up pressure on the Islamic republic to stop four years of stonewalling of IAEA experts seeking to follow up intelligence of such secret weapons-related experiments.  Iran denies such activities, asserting that they are based on intelligence fabricated by Washington. It also denies that its uanium enrichment program — under U.N. Security Council sanctions because it could manufacture fissile warhead material — is meant for anything else but making nuclear fuel.

In his previous report in September, Amano said he was “increasingly concerned” about a stream of intelligence suggesting that Iran continues to work secretly on developing a nuclear payload for a missile and other components of a nuclear weapons program.  He said “many member states” are providing evidence for that assessment, describing the information the agency is receiving as credible, “extensive and comprehensive.”  That report warned of the “possible existence in Iran of past or current undisclosed nuclear related activities” linked to weapons work. In particular, said the report, the agency continues to receive new information about “activities related to the development of a nuclear payload for a missile.”  Acquired from “many” member states, the information possessed by the IAEA is “extensive and comprehensive … (and) broadly consistent and credible,” said the report.

U.N. has new Iranian nuke arms claims, Associated Press, Nov. 4, 2011

See also the Security of Nuclear Materials

Iran’s Nuclear Program: the sequel

The U.N. nuclear agency said Friday [Sept. 2, 2011] it is “increasingly concerned” about a stream of intelligence suggesting that Iran continues to work secretly on developing a nuclear payload for a missile and other components of a nuclear weapons program.  In its report, the International Atomic Energy Agency said “many member states” are providing evidence for that assessment, describing the information it is receiving as credible, “extensive and comprehensive.”…The phrase “increasingly concerned” has not appeared in previous reports discussing Iran’s alleged nuclear weapons work and reflects the frustration felt by IAEA chief Yukiya Amano over the lack of progress in his investigations.

Other findings include:

— Confirmation of reports by diplomats to the AP that Iran has started setting up uranium enriching centrifuges at Fordow, a fortified facility dug into a mountain near the holy city of Qom. Iran intends to use Fordow to triple its 20-percent enrichment of uranium — a concern because that level is easier to turn into weapons grade uranium quickly than its main stockpile of low enriched uranium at 3.5 percent.

— Further accumulation of both low-enriched and higher enriched or 20 percent uranium. The report said Iran had now accumulated more than four tons of low enriched uranium and over 70 kilograms — more than 150 pounds — of higher enriched material. Those two stockpiles give it enough enriched uranium to make up to six nuclear warheads, should it choose to do so.

The report praised Iran for its decision earlier this month to allow IAEA Deputy Director General Herman Nackaerts to tour a facility where it is developing more efficient centrifuges, saying Iran “provided extensive information” on its development of such machines.

It, however was generally critical of Iran’s record of secrecy and lack of cooperation, noting that without increased openness on the part of the Islamic Republic the IAEA is unable to “conclude that all nuclear material in Iran is in peaceful activities.”

Excerpts, UN nuke agency ‘increasingly concerned’ about Iran, says evidence credible of nuke arms work, Associated Press, Sept. 2, 2011

IAEA Report

ISIS Report

When Sanctions Start

Iran and the IAEA

Unable to Control its Virtual Borders

Iran and the IAEA: hackers, spies and worms

The following is reported by the Associated Press

The U.N. nuclear agency is investigating reports from its experts that their cellphones and laptops may have been hacked into by Iranian officials looking for confidential information while the equipment was left unattended during inspection tours in the Islamic Republic, diplomats have told The Associated Press.  One of the diplomats said the International Atomic Energy Agency is examining “a range of events, ranging from those where it is certain something has happened to suppositions,” all in the first quarter of this year. He said the Vienna-based nuclear watchdog agency was alerted by inspectors reporting “unusual events,” suggesting that outsiders had tampered with their electronic equipment.  Two other diplomats in senior positions confirmed the essence of the report but said they had no further information… An agency official, who also spoke on condition that he not be identified, said strict security measures included inspectors’ placing their cellphones into seamless paper envelopes, then sealing these and writing across the seal and the envelope to spot any unauthorized opening while they were away.  He said inspectors are not allowed to take their cellphones with them while touring Iran’s uranium enrichment facilities and other venues. Laptops, he said, are either locked in bags or sealed the same way as cellphones when they are left temporarily unattended by inspectors. The computers also are sometimes left unattended in hotel rooms at the end of a work day, he said.  But the diplomat who spoke at greatest length about the reported breach said the Iranians had found ways to overcome the security measures.

Iran has been under IAEA inspections for nearly a decade after revelations that it was running a secret uranium enrichment program and has been hit with four rounds of U.N. Security Council sanctions over its refusal to halt the activity…

Olli Heinonen, who stepped down last year as the IAEA’s deputy director general in charge of investigating Iran’s nuclear program, said information on the laptops is encrypted — and therefore difficult to decipher. Anybody gaining access to information on cellphones would find little sensitive material, he said.  Heinonen speculated that any attempt to access such equipment might have been meant to plant spyware designed to infect the IAEA computer network once the cellphones or laptops are connected and siphon off information.  “It’s possible if there is tampering that something is planted in the computer and when you work with sensitive data it transmits it or it contaminates other computers with sensitive information — like Stuxnet,” he said.

IAEA officials attribute a temporary breakdown of Iran’s enrichment program late last year to the Stuxnet computer worm, and Tehran has acknowledged that Stuxnet affected a limited number of centrifuges — a key component in uranium enrichment — at its main uranium enrichment facility in the central city of Natanz. Tehran blames the United States and Israel for creating and planting the malware.

Excerpts from George Jahn, AP Exclusive: Diplomats: IAEA fears Iran hackers, Associated Press, May 19, 2011