根据国际能源机构的数据，到2030年，全球能源消耗量可能会增加18％，到2050年将增加39％。这将增加对各种能源来源——包括核电以及铀——的需求。
根据国际能源机构的数据，到2030年，全球能源消耗量可能会增加18％，到2050年将增加39％。这将增加对各种能源来源——包括核电以及铀——的需求。
“随着新的动力堆投运，旧的动力堆退役，铀的适当供应和管理将成为未来几十年能源供应的关键因素。” 原子能机构铀资源专家Adrienne Hanly说。“铀基燃料有望成为低碳核电的基本可靠来源。我们如何利用这种燃料将在很大程度上取决于可持续资源管理的新技术和新战略的发展。”
即使根据原子能机构对核电未来的低增长情况预测，即核电份额将从目前占能源市场的11％下降到2050年的6％，核发电容量也将增加24％。在高增长情况下，核电将增长2.8倍，核能在全球能源市场的份额将在2050年 增加到13.7％。
随着新核电技术的成熟，在某些情况下需要更少的铀或使用当今的核废物作为燃料，核发电量的增加并不一定意味着对开采铀的需求呈比例增加，尽管这种需求预计会增加。
铀行业将如何满足这种需求增长？虽然按照目前采矿实践可获得的铀资源足以使用至少100年，但正在研究确定利用世界铀资源的不同方法。
其中一种方法是从海水中提取铀。海水含有超过40亿吨的溶解铀， 远远超过陆地采矿活动可合理保证的供应量。从海洋中提取铀也有望成为补充全球铀供应的一种环保和可持续 的方式。
从海水中提取可用量的铀在理论上比从矿石中提取更简单。在海水中发现的铀是由水和含有铀的岩石之间的稳定化学反应产生的。当铀从海水中提取出来时，相同数量的铀会从岩石中浸出进行补充。这项研究的成功意味着供应几乎是无限的。
正在开发的海水提铀方法是把偕胺肟注入聚乙烯（一种普通塑料）制成的纤维中。偕胺肟是一种吸附二氧化铀并将其与纤维结合的物质。每立方米海水约有3毫克铀，相当于每升一粒盐。纤维经过大约一个月的浸泡后，科学家们将它们取出并用收集铀的酸对其进行处理，以使纤维适合再利用。
虽然这种方法已经研究了几十 年，但鉴于铀的低价格和常规矿的大量供应，其商业化尚未证明具有经济性。在过去五年中，从海洋中提取铀的成本下降了四分之一，达到440美元/千克。但是，这种方法要在商业规模上使用，价格需要进一步下降。
尽管有至少足够100年用的铀资源，但目前正在进行研究，以确定开发地球铀资源的不同方法。（照片：Orano）
和可持续获取铀同样重要的是有效利用和管理铀。小型模块化反应堆由于能够为更广泛的用途和应用提供灵活的动力，因此全世界对使用小型模块化反应堆增加了兴趣。小型模块化反应堆的一个优点是，根据所使用的技术，相同的输出可能需要更少的铀。
小型模块化反应堆的大规模部署可能会显著改变市场的需求和可预测性。当今，铀行业迎合了大型反应堆的不断需求，而这些反应堆的供应需求与小型反应堆的供应需求不同。
Hanly说，除了探索获取更多铀的新技术之外，核能工业还必须审查资源管理方面的实践，以确保可持续性。近 年来，原子能机构一直与联合国欧洲经济委员会（欧洲经委会）合作处理资源 管理问题，包括社会经济可行性、技术可行性和对估计的信心。
行性和对估计的信心。 “必须把铀视为一种能够帮助实现联合国可持续发展目标和气候承诺的低碳燃料。”欧洲经委会经济事务官员Harikrishnan Tulsidas说。“新技术将在铀生产可持续发展方面发挥关键作用。”
本文刊登在2018年6月《通报》版《铀：从勘探到治理》。
One such method consists of extracting uranium from seawater, which contains more than four billion tonnes of dissolved uranium — far outweighing the volume of reasonably assured supply from mining activities on land. Extraction from the sea also promises to be an environmentally friendly and sustainable way to supplement the global uranium supply.
Extracting usable quantities of uranium from seawater is theoretically simpler than from ore. The uranium found in seawater is created by steady chemical reactions between the water and rocks that contain uranium. And when uranium is taken from the seawater, the same amount later leaches from the rocks to replace it. Success in this research would mean a virtually unlimited supply.
Methods under development for extracting uranium from seawater involve infusing fibres made of polyethylene, a common plastic, with amidoxime, a substance that attracts uranium dioxide and binds it to the fibre. There are approximately three milligrams of uranium per cubic metre of water, or about the equivalent of a grain of salt per litre. After about a month of soaking them, scientists can remove the fibres and treat them with an acid that collects the uranium and makes the fibres suitable
for reuse.
Although this method has been researched for decades, its commercialization has not yet proven to be economical given the low price of uranium and the abundance of supply from conventional mines. Over the past five years, the cost of uranium extraction from the sea dropped by a factor of four to US $440 per kilogramme. But the price needs to fall significantly further for this method to be usable on a commercial scale.
While there is enough uranium for at least 100 years, research is under way to identify different methods for tapping into the Earth’s uranium resources. (Photo: Orano)
Equally important as sustainable uranium acquisition is the efficient use and management of the uranium. Interest worldwide has increased in the use of small modular reactors (SMRs), thanks to their ability to generate flexible power for a wider range of uses and applications. One advantage of SMRs is that — depending on the technology used — less uranium could be required for the same output.
Large scale SMR deployment could significantly alter demand and the predictability of the market. Today, the industry caters to a constant demand from large reactors, whose supply needs are different from those of small reactors.
In addition to exploring new technologies for obtaining more uranium, the nuclear energy industry will have to examine practices in resource management to ensure sustainability, Hanly said. The IAEA has been working with the United Nations Economic Commission for Europe (UNECE) in recent years to address issues in resource management, including socioeconomic viability, technological feasibility and confidence in estimates.
“Uranium has to be seen as a low-carbon fuel that can help realize many of the United Nations Sustainable Development Goals and climate commitments,” said Harikrishnan Tulsidas, Economic Affairs Officer at UNECE. “New technologies will have a critical role to play in making uranium production sustainable.”