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[en] If fewer forced outages are a sign of improved safety, nuclear power plants have become safer and more productive. There has been a significant improvement in nuclear power plant performance, due largely to a decline in the forced outage rate and a dramatic drop in the average number of forced outages per fuel cycle. If fewer forced outages are a sign of improved safety, nuclear power plants have become safer and more productive over time. To encourage further increases in performance, regulatory incentive schemes should reward reactor operators for improved reliability and safety, as well as for improved performance
[en] This paper discusses the economic assumptions in the U.S. National Academy of Sciences' report, Management and Disposition of Excess Weapons Plutonium: Reactor-Related Options (1995). It reviews the Net Present Value approach for discounting and comparing the costs and benefits of reactor-related options. It argues that because risks associated with the returns to plutonium management are unlikely to be constant over time, it is preferable to use a real risk-free rate to discount cash flows and explicitly describe the probability distributions for costs and benefits, allowing decision makers to determine the risk premium of each option. As a baseline for comparison, it assumes that one economic benefit of changing the current plutonium management system is a reduction in on-going Surveillance and Maintenance (S and M) costs. This reduction in the present value of S and M costs can be compared with the discounted costs of each option. These costs include direct construction costs, indirect costs, operating costs minus revenues, and decontamination and decommissioning expenses. The paper also discusses how to conduct an uncertainty analysis. It finishes by summarizing conclusions and recommendations and discusses how these recommendations might apply to the evaluation of Russian plutonium management options. (author)
[en] This paper presents finite element data for 92 reinforced butt-welded branch outlet piping junctions designed according to the ASME B31.3 process piping code, for the purpose of investigating their effectiveness in the light of data for un-reinforced fabricated tee junctions. The data suggest that the reinforcement provided under the ASME B31.3 design is effective for the internal pressure load case and all external bending moment loads with the exception of branch out-of-plane bending for thin-walled assemblies
[en] The determination of plantar stresses using computational footwear models which include temperature effects are crucial to predict foam performance in service and to aid material development and product design. Finite Element Method (FEM) provides an efficient computational framework to investigate the foot-footwear interaction. The aim of this research is to use FEM to investigate the effect of varying footwear temperature on plantar stresses. The results obtained will provide data which can be used to help optimise shoe design in terms of minimising damaging stresses in the foot particularly for individuals with diabetes who are susceptible to lower extremity complications. The FE simulation results showed significant reductions in foot stresses with the modifications from FE model (1) without footwear to model (2) with midsole only and to model (3) with midsole and insole. In summary, insole and midsole layers made from various foam materials aim to reduce the Ground Reaction Forces (GRF's) and foot stresses considerably and temperature variation can affect their cushioning and consequently the shock attenuation properties. The loss of footwear cushioning effect can have important clinical implications for those individuals with a history of lower limb overuse injuries or diabetes.
[en] This paper describes a micro-economic, cost-engineering model of a centralized (Generic Interim Storage Facility - GISF) facility to monitor LWR irradiated fuel with particular attention to scale economies (e.g., to compare the likely costs at a power plant site or at regional, national and international facilities). This paper is based on the cost estimates of the Private Fuel Services Facility (PFSF) on the Skull Valley Band of Goshute Indians' Reservation in Utah, licensed by the US NRC in 2006 to centralize storage of 40.000 metric tons of heavy metal (MTHM) for 20 to 40 years. Assuming movement of the 40.000 MTHM every 40 years to a new facility, the levelized costs are 144 dollars/kg without high security and physical protection, and 208 dollars/kg with high security through 2111 (assuming disposal within a century), or about 0.50 dollars/MWh to 0.75 dollars/MWh depending on the burnup and thermal efficiency of the nuclear power plant. This cost estimate is generalized to explore scale economies for facilities with and without high security and physical protection. There are declining levelized costs with increasing size to 120.000 MTHM without high security, and to 500.000 MTHM with high security, i.e., the higher the level of security, the stronger the economies of scale. (author)
[en] State public utility commissions in the United States have implemented incentive regulations to promote the operating efficiency of nuclear power plants. This paper surveys these incentive programs, focusing on the performance-based pricing approach. Our findings suggest that the performance-based price should be set between the electric utility's avoided cost and the marginal cost of generating electricity at the nuclear power plant. 18 refs., 1 fig., 1 tab
[en] This paper proposes criteria for determining ''intermediate sustainability'' over a 500-year horizon. We apply these criteria to Light Water Reactor (LWR) technology and the LWR industry. We conclude that LWR technology does not violate intermediate sustainability criteria for (1) environmental externalities, (2) worker and public health and safety, or (3) accidental radioactive release. However, it does not meet criteria to (1) efficiently use depleted uranium and (2) avoid uranium enrichment technologies that can lead to nuclear weapons proliferation. Finally, current and future global demand for LWR technology might be below the minimum needed to sustain the current global LWR industry. (author)
[en] This paper discusses the calculation of the levelized unit costs for non-electricity products and jointly produced outputs, such as electricity with fresh water, hydrogen, heat, or actinide destruction services. Where nuclear energy systems produce multiple products, each of which is sold in a fully functioning market (as is usually the case for electricity), market prices can be used to determine whether total costs are less than total revenues, i.e., whether a joint-product nuclear energy system is competitive. Problems in allocating fixed costs (for example, the cost of the reactor) arise when at least one of the joint products is sold under contract, for example, where heat or water are sold to a municipal utility for local distribution. In these cases, the price, based on cost, of the product is negotiated. How should this cost be determined?
[en] This paper describes some of the results of a Nuclear Energy Agency (of the Organisation for Economic Cooperation and Development) report to be published in 2015: Costs of Decommissioning Nuclear Power Plants. Because of the confidential nature of the data obtained by questionnaires from representatives of NEA member countries, this paper discusses the translation of publicly available decommissioning costs and estimates with an emphasis on completed decommissioning costs in the U.S. for Haddam Neck, Maine Yankee, Trojan, and Rancho Seco. This translation is from the codes of accounts used by TLG Services into the IAEA/EC/NEA International Structure for Decommissioning Costing, ISDC (2012). We show how to dis-aggregate the TLG Work Breakdown Structure, WBS, into Level 3 ISDC codes and re-aggregate to categories that allow cross-country comparisons. We find that while the cost of decontaminating and dismantling a nuclear power unit has changed little over time, uncertainties remain in estimating waste disposal costs, on-site spent fuel storage, and site release criteria. The approximate total decommissioning cost including dismantling, waste management and project management, appears to be 500 millions dollar per nuclear power unit