Separative work units

Abstract: This paper evaluates possible scenarios for Pakistan's uranium enrichment and plutonium production programs since the late 1970s by using Pakistan's supply of natural uranium as a constraint. Since international sanctions have prevented Pakistan from importing uranium for decades, it has had to rely on domestic uranium production—currently estimated as approximately 40 tons a year. The paper divides the development of Pakistan's uranium enrichment and plutonium production programs into three broad periods: from the beginning in the late 1970s until the 1998 nuclear tests; from 1999 to the present; and from the present to 2020; and considers how Pakistan could allocate its domestic uranium between its uranium enrichment and plutonium production programs for each period. This assessment is completed for enrichment capacities ranging from 15,000 to 75,000 separative work units (SWU) and takes into account the construction of the second and third plutonium production reactors at Khushab. The study finds that ...

Abstract: New public information allows a fresh estimate of China's current and under-construction uranium enrichment capacity. This paper uses open source information and commercial satellite imagery to identify and offer estimates of the capacity of China's 10 operating enrichment facilities, located at 4 sites, using centrifuge technology most likely based on adapting Russian technology. The total currently operating civilian centrifuge enrichment capacity is estimated to be about 4.5 million separative work units/year (SWU/year), with additional capacity estimated to be about 2 million SWU/year under construction. Also China could have an enrichment capacity of around 0.6 million SWU/year for non-weapon military uses (i.e., naval fuel) or dual use. These estimates are much larger than previous public estimates of China's total enrichment capacity. Further expansion of enrichment capacity may be likely since China will require about 9 million SWU/year by 2020 to meet the enriched uranium fuel needs for its plann...

Abstract: Most nuclear power plants run for electricity, generation worldwide need enriched uranium as a fuel. This makes the reliable long-term supply of uranium separative work services indispensable for the operators of such reactors. The enrichment step at the front end of the nuclear fuel cycle gives rise to roughly one third of the total cost. These indications underline the great importance of uranium enrichment for the worldwide generation of electricity in nuclear power plants. Enriched uranium is produced from natural uranium by raising the concentration by weight of the lighter isotope (from 0.771 wt.% in natural uranium up to 5.0 wt.% in enriched uranium to be used in civilian nuclear power plants) by partial separation of the U-235 isotope from the U-238 isotope. This isotope separation (or enrichment in the U-235 isotope) is carried out in separation plants. As a rule, the natural uranium to be enriched is supplied by the customer; consequently, enrichment is a service. It is measured in separative work units (SWU).

Abstract: International organizations regularly produce global energy demand scenarios. To account for the increasing population and GDP trends, as well as to encompass evolving energy uses while satisfying constraints on greenhouse gas emissions, long-term installed nuclear power capacity scenarios tend to be more ambitious, even after the Fukushima accident. Thus, the amounts of uranium or plutonium needed to deploy such capacities could be limiting factors. This study first considers light-water reactors (LWR, GEN III) using enriched uranium, like most of the current reactor technologies. It then examines the contribution of future fast reactors (FR, GEN IV) operating with an initial fissile load and then using depleted uranium and recycling their own plutonium. However, as plutonium is only available in limited quantity since it is only produced in nuclear reactors, the possibility of starting up these Generation IV reactors with a fissile load of enriched uranium is also explored. In one of our previous studies, the uranium consumption of a third-generation reactor like an EPR™ was compared with that of a fast reactor started up with enriched uranium (U5-FR). For a reactor lifespan of 60 years, the U5-FR consumes three times less uranium than the EPR and represents a 60% reduction in terms of separative work units (SWU), though its requirements are concentrated over the first few years of operation. The purpose of this study is to investigate the relevance of U5-FRs in a nuclear fleet deployment configuration. Considering several power demand scenarios and assuming different finite quantities of available natural uranium, this paper examines what types of reactors must be deployed to meet the demand. The deployment of light-water reactors only is not sustainable in the long run. Generation IV reactors are therefore essential. Yet when started up with plutonium, the number of reactors that can be deployed is also limited. In a fleet deployment configuration, U5-FRs appear to provide the best solution for using uranium, even if the economic impact of this consumption during the first years of operation is significant.