To ensure the long-term supply and sustainability of uranium fuel, exploring alternative resources is essential, particularly considering that terrestrial reserves of uranium are limited (about 4.6 million tons). Since the amount of uranium dissolved in seawater is approximately 1000 times that of terrestrial reserves (i.e., about 4.5 billion tons), uranium extraction from seawater (UES) can be an alternative resource. However, the ultra-low concentration of uranium in seawater (about 3.3 ppb) poses a significant challenge in achieving economic feasibility for UES. This paper introduces case studies on the cost analysis of systems for recovering uranium from seawater, specifically focusing on braided fiber-based adsorbents developed by JAEA and ORNL. The cost analysis has been conducted based on using the deployment of these adsorbents on the bottom of the sea, which is a passive deployment method, thereby reducing the total costs of recovery. The analysis results can be used to identify R&D areas necessary for reducing cost components, making UES economically feasible.
Uranium extraction from seawater has been a topic of considerable interest over the past decades. However, Commercial facilities for uranium extraction from seawater have not yet been constructed due to its lack of economic feasibility. With the increasing demand for sustainable energy sources, there is a growing interest in eco-friendly uranium extraction methods. Despite this, the safeguards associated with these extraction techniques remain relatively under-researched, necessitating comprehensive studies that address both the economic feasibility and safeguards approach. The Korea Hydro & Nuclear Power Central Research Institute is poised to elucidate the economic value of uranium extraction from seawater and embark on research to extract Yellow Cake from seawater on a laboratory scale. Given these advancements, it becomes imperative to consider the approach to safeguards. In this study, a comprehensive review was conducted to understand the relevant regulations that encompass both international obligations in partnership with the IAEA and domestic guidelines, specifically the Nuclear Safety Act. Emphasis was placed on a detailed examination of the IAEA’s comprehensive safeguards agreement and its additional protocol, focusing on deriving the necessary regulatory timings, subjects, and methodologies for effective reporting and verification. We reviewed the safeguards guidelines and the IAEA policy to confirm the international non-proliferation obligations. The study also reviewed the impact of the State-Level Approach promoted by the IAEA and its implications on state-specific factors and evaluations of state technological advancement. Additionally, the regulatory aspects of extracted uranium as an internationally regulated material under the Nuclear Safety Act were critically assessed. In conclusion, this study explains the international and domestic regulatory considerations for uranium extraction from seawater. Ultimately, this study will provide valuable understanding for policymakers, researchers, and practitioners involved in uranium extraction from seawater. Additionally, we expect that this study will contribute to establishing the safeguards approach and regulatory framework for the commercialization of uranium extraction from seawater in the ROK.
Given the limited terrestrial reserves of uranium (about 4.6 million tons), exploring alternative resources is essential to ensure the long-term supply and sustainability of nuclear energy. Uranium extraction from seawater (UES) is a potential solution to this issue since the amount of uranium dissolved in seawater (about 4.5 billion tons) is approximately 1000 times that of terrestrial reserves. However, the ultra-low concentration of uranium in seawater (about 3.3 ppb) makes it a challenging task to make UES economically feasible. This paper provides an overview of the current status of UES technology, which has evolved over the past seven decades. Starting from inorganic adsorbents such as hydrous titanium oxide in the 1960s, amidoxime-based fibrous adsorbents gained the most attention until the early 2010s due to their ease of deployment in actual seawater conditions and high affinity for uranium. Nowadays, research on organic adsorbents with microstructures is prevailing due to their ability to easily control surface area and compositions. In addition, this study identifies the key issues that need to be addressed to make UES technology economically viable.
The ability to recover the nearly limitless supply of uranium contained within the world’s oceans would provide supply security to uranium based fuel cycles. Therefore, in addition to U.S. national laboratories conducting R&D on a system capable of harvesting seawater uranium, a number of collaborative university partners have developed alternative technologies to complement the national laboratory scheme. This works summarizes the systems analysis of such novel uranium recovery technologies along with their potential impacts on seawater uranium recovery. While implementation of some recent developments can reduce the cost of seawater uranium by up to 30%, other researchers have sought to address a weakness while maintaining cost competitiveness.
아미드옥심기와 복합재료 섬유흡착제를 제조하였고 해수로부터 우라늄이온의 분리 특성을 조사하였다. 흡착량은 흡착시간이 증가함에 따라 증가하였고 An:TEGMA:DVB의 몰비가 1:0.1:0.003인 수지가 pH 8 부근에서 최대 흡착능을 나타내었다. 또한 흡착량은 CFA에 첨가한 흡착제의 양이 증가함에 따라 증가하였으며 1시간 까지 선형적으로 증가하였고, 25˚C에서 최대흡착량을 나타내었다. 한편 Ca, Mg 이온은 흡-탈착 cycle이 반복될수록 증가하였으며 그양은 각각 0.3, 0.9mmole/g-Ads로 우라늄 이온의 그것보다 매우 낮았다. 흡착된 우라늄 이온의 탈착은 흡착제의 종류에 관계없이 약 30분 이내에 거의 100% 탈착되었다.
해수로 부터 우라늄 분리를 위한 아미드옥심형 섬유복합재료 흡착제를 제조하였고, IR, 팽윤도 실험, CHN 원소분석, SEM 및 흡착능 실험을 통하여 그 특성을 알아보았다. AN-TEGMA 및 AN-TEGMA-DVB 공중합체의 팽윤율과 수율은 가교제의 함량이 증가할 수록 감소하였으며, 수율은 AN-TEGMA 공중합체의 경우 85-92%였고 AN-TEGMA-DVB 공중합체는 82-88%였다. 다공도도가교체의 함량이 증가할 수록 감소하였으며 AN-TEGMA-DVB 공중합체가 AN-TEGMA 공중합체보다 작았다. 또한 전자현미경 관찰 결과 제조한 섬유 복합재료 흡착제의 표면에 흡착제가 고루 분포되어 있는 것을 확인하였고, 흡착제의 최적 첨가량은 40wt%이었다. 섬유복합재료 흡착제의 우라늄 흡착량은 pH 8 부근에서 최대 였으며, 해수의 pH가 8.3임을 감안할 때 해수 우라늄 분리에 적합한 소재 임을 알 수 있었다.