How lasers could help provide fuel for nuclear reactors
How lasers could help provide fuel for nuclear reactors
激光技术如何助力核反应堆燃料供应
EXECUTIVE SUMMARY Outside the small town of Paducah, Kentucky, a wealth of uranium is locked away in thousands of storage cylinders filled with waste material from a now-closed nuclear enrichment facility. Lasers could help get it out. A company called Global Laser Enrichment (GLE) is looking to reprocess this old material with a new technology called laser enrichment. It could be more efficient than conventional enrichment methods, allowing the company to refresh the material and produce feedstock at the same concentration as a natural mined source. And in the future, the company claims, laser enrichment could be used to make material for nuclear fuel, including the kind used in advanced reactors.
执行摘要 在肯塔基州帕迪尤卡市郊外，大量的铀被封存在数千个储存罐中，这些罐子里装满了来自一家现已关闭的核浓缩设施的废料。激光技术或许能将这些铀提取出来。一家名为“全球激光浓缩”（Global Laser Enrichment，简称 GLE）的公司正计划利用一种名为“激光浓缩”的新技术对这些旧材料进行再处理。该技术可能比传统的浓缩方法更高效，使公司能够对材料进行提纯，并生产出与天然开采矿石浓度相当的原料。该公司声称，未来激光浓缩技术还可用于制造核燃料，包括用于先进反应堆的燃料。
Nuclear power provides about 9% of global electricity today, and that fraction could tick up as major world powers like the US and China look to build new reactors, including some based on next-generation technology. New, cheaper methods to obtain fuel could help ensure that those nuclear projects stay on track.
目前，核能约占全球电力的 9%。随着美国和中国等主要大国寻求建造包括基于下一代技术在内的新型反应堆，这一比例可能会上升。获取燃料的更廉价新方法将有助于确保这些核项目顺利推进。
Naturally occurring uranium is largely made up of uranium-238 (over 99%) and uranium-235 (about 0.7%). Uranium-235 is the fissile type, meaning that, when hit with slow low-energy neutrons, it can sustain a chain reaction that generates electricity. So reactors generally use material with a higher concentration of U-235 than what’s pulled from the ground. Today’s conventional reactors usually use low-enriched uranium, typically is about 5% U-235, though some advanced reactor designs will use fuel that’s up to 20% U-235.
天然铀主要由铀-238（超过 99%）和铀-235（约 0.7%）组成。铀-235 是可裂变同位素，这意味着当它受到缓慢的低能中子撞击时，可以维持产生电力的链式反应。因此，反应堆通常使用 U-235 浓度高于天然矿石的材料。当今的常规反应堆通常使用低浓缩铀，其 U-235 浓度约为 5%，尽管一些先进的反应堆设计会使用浓度高达 20% 的 U-235 燃料。
Today, centrifuges are the dominant tech used to enrich uranium. The equipment essentially takes uranium-containing material and spins it around incredibly quickly, so the heavier material (which contains U-238) spins out to the edge, while the lighter material (which has U-235) stays closer to the center. (If you’ve ever swung a mustard bottle to get the last of it out, you’ve used the same basic idea behind a centrifuge.) Then the material that has a higher concentration of U-235 can go on to be made into nuclear fuel.
目前，离心机是用于铀浓缩的主流技术。该设备本质上是将含铀材料高速旋转，使较重的材料（含有 U-238）甩向边缘，而较轻的材料（含有 U-235）则留在靠近中心的位置。（如果你曾经为了挤出最后一点芥末而甩动瓶子，你就已经用到了离心机的基本原理。）随后，U-235 浓度较高的材料便可被加工成核燃料。
Laser enrichment, on the other hand, takes advantage of the fact that all molecules vibrate and rotate at an atomic scale in ways that depend on their specific material. Even different uranium isotopes have distinct fingerprints. Lasers are so precise they can target one particular material (like molecules that contain U-235, for example). If you shine a laser at a mixture, you can selectively excite just the material you’re targeting, giving it a bit more energy. This changes the way it behaves, which can make it easier to separate out the material you want using chemical or physical methods.
另一方面，激光浓缩利用了所有分子在原子尺度上根据其特定材料进行振动和旋转的特性。即使是不同的铀同位素也有独特的“指纹”。激光非常精确，可以瞄准特定的材料（例如含有 U-235 的分子）。如果你用激光照射混合物，你可以选择性地激发目标材料，使其获得更多能量。这会改变其行为方式，从而更容易通过化学或物理方法分离出所需的材料。
A wide range of separation approaches have been developed in research and industry. Some aim to electrically charge U-235 atoms, allowing them to be moved with electrostatic or magnetic fields. Others change how the material reacts chemically. The details of GLE’s specific technology are classified, and company officials declined to share how the process works.
研究界和工业界已经开发出多种分离方法。有些旨在使 U-235 原子带电，从而利用静电场或磁场对其进行移动。另一些则改变材料的化学反应方式。GLE 具体技术的细节属于机密，公司官员拒绝透露其工作原理。
There’s been interest in using lasers for uranium enrichment for decades, says Charles Forsberg, a principal research scientist in nuclear science and engineering at MIT. However, in their early days lasers tended to be high-maintenance, unstable and difficult to operate. They’ve improved dramatically, making laser enrichment a more attractive prospect than it was during the early research.
麻省理工学院核科学与工程系首席研究科学家查尔斯·福斯伯格（Charles Forsberg）表示，几十年来，人们一直对利用激光进行铀浓缩很感兴趣。然而，在早期，激光设备往往维护成本高、不稳定且难以操作。如今，激光技术已得到显著改进，使得激光浓缩比早期研究阶段更具吸引力。
Even more than technological improvements, a recent geopolitical shift could boost new enrichment technology. Russia has the largest uranium enrichment ecosystem in the world, and the country has historically dominated the market. “Nobody in the West was going to build a new enrichment plant while the Russians flooded the world with enriched uranium,” says Forsberg. Since the start of the Ukraine war, however, countries including the US and UK have taken steps to limit or ban imports of Russian uranium. That’s opened the door for companies to set up new enrichment operations, including some that use new technologies, Forsberg says.
除了技术进步之外，近期的地缘政治转变也可能推动新的浓缩技术。俄罗斯拥有世界上最大的铀浓缩生态系统，历史上一直主导着该市场。福斯伯格说：“当俄罗斯向全球大量供应浓缩铀时，西方国家没人会去建造新的浓缩工厂。”然而，自乌克兰战争爆发以来，包括美国和英国在内的国家已采取措施限制或禁止进口俄罗斯铀。福斯伯格认为，这为企业建立新的浓缩业务打开了大门，其中一些企业正在采用新技术。
Demand for fuel is increasing as countries look beyond Russia for uranium supply. “The gap is just becoming bigger and bigger, and this technology is right in the middle,” says Christo Liebenberg, president of LIS Technologies, one of the companies aiming to build laser enrichment capacity in the US. LIS Technologies was founded in 2023, and the company recently purchased a 200-acre site in Oak Ridge, Tennessee. It’s currently in the pre-application process with the US Nuclear Regulatory Commission for its facility. The company plans to take in natural-grade uranium and make a product that’s roughly 5% U-235, though it hopes to eventually make more concentrated material that can be used as fuel for next-generation reactors.
随着各国寻求俄罗斯以外的铀供应，对燃料的需求正在增加。LIS Technologies 公司总裁克里斯托·利本伯格（Christo Liebenberg）表示：“供需缺口正变得越来越大，而这项技术正处于核心位置。”该公司旨在在美国建立激光浓缩能力。LIS Technologies 成立于 2023 年，最近在田纳西州橡树岭购买了一块 200 英亩的场地。目前，该公司正处于向美国核管理委员会提交设施预申请的过程中。该公司计划接收天然级铀，并生产出 U-235 浓度约为 5% 的产品，同时也希望最终能制造出更高浓度的材料，用作下一代反应堆的燃料。
GLE is taking a different approach: Rather than using its technology to enrich freshly mined material to the 5% concentration that can be used in fuels, it’s hoping to start by rehabilitating old waste. The company has a contract with the US Department of Energy to reprocess waste material at the enrichment site in Paducah. The facility could enrich up to 200,000 metric tons of material that contains small amounts of uranium leftover from an older enrichment process. GLE is taking the material that’s at least 0.25% U-235 and enriching it to about 0.7%. That material can then be further processed and slotted into the uranium supply chain in place of freshly mined material. “It’s kind of like a large aboveground uranium mine for us,” says Nima Ashkeboussi, vice president of government relations and communications at GLE.
GLE 则采取了不同的策略：它没有利用其技术将新开采的矿石浓缩至燃料所需的 5% 浓度，而是希望从修复旧废料入手。该公司与美国能源部签订了合同，对帕迪尤卡浓缩点的废料进行再处理。该设施可处理多达 20 万吨含有少量旧浓缩工艺残留铀的材料。GLE 将 U-235 含量至少为 0.25% 的材料浓缩至约 0.7%。这些材料随后可进行进一步加工，并替代新开采的矿石进入铀供应链。GLE 政府关系与传播副总裁尼玛·阿什克布西（Nima Ashkeboussi）表示：“这对我们来说就像是一个大型的地面铀矿。”
While each one of its units is more complex and expensive than a centrifuge, far fewer are needed to do the same work. A similar centrifugation plant would have many thousands of centrifuges working together, but a full-scale plant using GLE’s laser enrichment process would have fewer than a thousand of its units, says Stephen Long, the company’s CEO.
虽然其每个单元都比离心机更复杂、更昂贵，但完成同样的工作所需的数量要少得多。该公司首席执行官斯蒂芬·朗（Stephen Long）表示，类似的离心工厂需要数千台离心机协同工作，而使用 GLE 激光浓缩工艺的全规模工厂仅需不到一千个单元。