伊朗’s Fuel Fabrication: Step closer to energy independence or a bomb?

By Ivanka Barzashka and Ivan Oelrich

昨天，在伊朗的国家核技术日，艾哈迈迪尼贾德总统宣布了该国的最新核进展，这似乎已成为国家骄傲和国际的重要来源 冤仇。4月9日是伊朗声称在2006年丰富其第一批铀的日子。昨天，艾哈迈迪尼贾德（Ahmadinejadmore accurate” type of centrifuge at the Fuel Enrichment Plant (FEP) at Natanz.

燃料制造设施，这是front-end fuel cycle是制造核反应堆燃料的地方。对于浅水反应堆（LWR），例如灌木丛中的铀，铀被开采，变成黄色的蛋糕并转化为铀六氟化铀（UF6），使用中心体放射线富集，并转换为氧化物氧化物弹丸，使其变成铀颗粒。杆，进入反应堆芯。对于加压的重水反应堆（PHWR），例如Arak中的一个，铀不需要富集，因此黄色的蛋糕直接转化为氧化铀颗粒。

Fuel fabrication is not nearly the technical challenge of building and operating a cascade of centrifuges, but it is not trivial either. No one wants a multi-billion dollar reactor contaminated because a fuel element has failed, so quality control is vital. Fuel rods must not rupture or corrode while in the reactor, which requires careful control of the purity of materials and integrity of seals.

伊朗has claimed that its uranium enrichment program is meant for energy production and is wholly peaceful, while much of the rest of the world has worried that the centrifuges in Natanz are really intended to produce highly enriched uranium (HEU) for a nuclear weapon. The Iranians claim that they need to enrich their own uranium because, based on past experience, they cannot depend on foreign suppliers. The argument of energy independence rang hollow because Iran did not have a fuel fabrication facility. This meant that their indigenously enriched uranium would still have to be exported for fabrication into fuel elements and re-imported, leaving them still vulnerable to foreign pressure. If they now have an operational fabrication facility, they will complete the front-end nuclear fuel production, making their energy independence arguments for enrichment more plausible, or at least less implausible.

虽然，并非有消息说，FMP的建设始于2004年，该公司正在运作（这是在2009年2月的IAEA报告中宣布的），但燃料制造设施本身的出现很重要。只有三个国家，其中十分之一拥有核电站的国家，拥有核燃料循环的所有要素：从铀矿到反应堆燃料生产。碰巧的是，这三个国家还拥有核武器。当伊朗的核反应堆运行时，伊朗将独立控制核的所有要素燃油周期，，，，thereby advancing their claim for energy independence.

But Iran has not closed the front-end fuel cycle yet. The FMP was originally planned to produce nuclear fuel for the heavy water reactor in Arak, which is still under construction, not for the soon to be in operation light water reactor in Bushehr. Yet yesterday, an伊朗ian news sourcereported that, “Iran has completely gained access to management of nuclear fuel production which makes the country self-sufficient in production of nuclear fuel for heavyandlight water reactors.” [emphasis added] Inanother article，，，，IRNA even mentions the capacity: “FMP is to produce 10 tons of natural fuel each year used for 40 megawatts heavy-water reactors in Arak and 30 tons of five percent enriched uranium for light water reactors.”

According to theFebruary IAEA report，，，，after an inspection at FMP, the IAEA inspectors concluded that “the process line for the production of重水反应堆燃料的天然铀颗粒已经完成并生产了燃油棒。” [强调]。由于国际原子能机构和伊朗之前都没有提到FMP的LWR燃料产生能力，因此我们对植物实际上可以做什么持怀疑态度。我们怀疑以夸大其核能力而闻名的伊朗更有可能意味着工厂可以potentially生产LWR的燃料。

Light water reactor (LWR) fuel is not the same as heavy water reactor (HWR) fuel. The uranium oxide fuel pellets are similar, except the LWR fuel is made from expensive, hard-to-get enriched uranium and the HWR fuel is made from cheap natural uranium. In both cases, the pellets are stacked and covered with clad zircalloy (zirconium, coated with iron and other trace elements). However, the geometry and construction of the fuel element assemblies is very different (personal communication from Ehud Greenspan, a nuclear engineering professor at UC Berkley). A HWR has much simpler fuel assemblies than those of a LWR. The PWR rods have a larger diameter, are shorter, and have a thinner coating of metal. [pp 241-291]由于它们的尺寸，LWR燃料棒必须自由站立并具有更大的功率密度。LWR燃料的产生还需要更加关注临界危险。pp 33-39] All bundles in a HWR are identical, they do not have different uranium concentration like those in the LWR, which can range anywhere from 3 to 5 percent LEU and are arranged in special patterns optimize the neutron flux throughout the core.

简而言之，LWR和PHWR的燃料制造原理和技术都很接近，但是燃油棒设计却大不相同。因此，如果伊朗有技术的能力，他们很可能两者都做。但是，这可以在同一设施中发生吗？

印度是唯一在同一地点为其LWR（BWR）反应堆及其PHWR生产核燃料的国家 -Nuclear Fuel Complex在海得拉巴。印度进口其丰富的铀。尽管两种燃料类型的锆生产植物都是相同的，但是在两个单独的设施中，原材料（在一种情况下，在一种情况下，在一种天然铀和另一个富集的铀中）转化为UO2颗粒。燃料棒还在该建筑群中的两个不同位置组装：陶瓷燃料制造厂和富集的铀燃料厂。

此外,俄罗斯轻水反应堆Bushehr, whose construction was completed this year and will soon be in operation, uses Russian-made fuel rods. Iran and Russia have signed a long-term agreement for fuel supply and it is unlikely that Iran would risk damaging the VVER-426 reactor with domestically manufactured fuel rods, especially when it does not have the design plans, which Russia is not going to offer up. So, Iranian theoretical LWR fuel manufacturing capacity will at best have to wait for the construction of another nuclear reactor, at least ten years from now.

According to the Nuclear Energy Agency, if a county wants to be independent from foreign nuclear fuel vendors in a fairly short time, a heavy water reactor is the way to go. It is cheap and simple: uranium does not have to be enriched, natural uranium is easily converted to uranium oxide, the design is simple and the fuel rods are all the same. It requires only a small factory and has lower labor costs. In addition, a PWR can be designed to have a continuous fueling system so it does not have to be shut down to be refueled. Countries with moderate technological capabilities like South Korea, Argentina, and Romania have national heavy water fuel fabrication facilities. So, it is understandable why Iran would think this approach is attractive.

然而，伊朗动机仍然没有明确的削减。

一方面，燃料制造设施的就职典礼是个好消息。这意味着伊朗确实正在尝试生产反应堆燃料，这为他们的丰富主张带来了合法性。此外，如果查看了燃油周期的单独部分，则燃料制造厂本身没有双重用途。普林斯顿的斯科特·肯普（Scott Kemp）不久前提到，如果伊朗将其UF6转换为UO2，这将成为保障。如果伊朗开始使用LWR的燃料制造工艺，将大部分的Leu转变为Natanz添加到氧化铀中，并将其锁定在锆球管中，这将大大减少将LEU批量回收到炸弹级铀铀的可能性。

但是，如果FMP在Arak中为重水反应堆生产核燃料，这是个坏消息。重水反应堆可能对核电计划感兴趣，因为它们不需要富集的铀。例如，加拿大仅操作重水反应堆（称为坎杜) domestically and has sold these commercially. But heavy water reactors are also ideally suited for producing plutonium that can be used in a nuclear weapon. Once again, Iranian moves can be interpreted as moving toward energy independence or toward a nuclear weapons capability, or both.

这篇文章最后更新于2009年9月30日due to a factual error in the number of countries possessing all the components of the fuel cycle. Only the US, Russia and China currently have all the elements – France shut down its last uranium mine in 2001 and India has only a test enrichment plant and actually imports its enriched uranium.