Competitiveness of Small-Medium, New Generation Reactors: A Comparative Study on Capital and O&M Costs

Abstract

Smaller size reactors are going to be an important component of the worldwide nuclear renaissance. An inappropriate application of the economy of scale would label the small-medium size reactors as not economically competitive with larger plants because of capital costs ($/kWe) and O&M costs ($/kWh) that would appear to be significantly higher. However, the economy of scale applies only if the considered designs are similar, which is not the case here, since the small size allows original design solutions not accessible to large size reactors. In the paper the historical trend of capital costs vs. plant size is estimated from literature, and a reference exponent factor for the economy of scale for the light water reactor is derived. Then the paper identifies and briefly discusses the various factors which, beside size, contribute in differentiating the capital cost of smaller reactors with respect to large reactors. In this reference frame the evaluation for of the following factors is provided: · design characteristics · modular build · multiple units · accelerated learning in construction · operation, and shorter construction time. The IRIS reactor is used as the example of small modular reactor (SMR), but the analysis and conclusions are applicable to the whole spectrum of small nuclear plants. The results show that when all these factors are accounted for in a set of realistic and comparable configurations, and with the same power installed in the site, the capital costs of small and large plants installations are practically equivalent. Considering the O&M cost the paper shows how the plant size is not the only and fundamental cost driver. In fact there is a range of other factors (e.g. location, regulatory issues, capacity factor, plant obsolescence and number of reactors on a site) able to influence the annual O&M cost for a specific plant. The paper provides a preliminary evaluation of these factors by historical analysis of reactors built in the United States, concluding, also in this case, that when all the factors are considered the difference between the average cost ($/KWh) of Large Size vs. SMR is about 20% less than would be expected.

Small modular reactor: First-of-a-Kind (FOAK) and Nth-of-a-Kind (NOAK) Economic Analysis

“…The average share of debt for large reactor projects is 65%. This value for SMRs is approximately 50% (Carelli 2008;INL 2012). The maximum share of debt for large reactors and SMRs are approximately 93% and 69% respectively (Carelli 2008).…”

“…This value for SMRs is approximately 50% (Carelli 2008;INL 2012). The maximum share of debt for large reactors and SMRs are approximately 93% and 69% respectively (Carelli 2008). In this economic model, the cases are performed at the average SMR debt share.…”

Impact of the External Factors in the Nuclear Field: A Comparison Between Small Medium Reactors vs. Large Reactors

“…Obviously if "economies of scale" is the unique driver for the cost estimation SMR are not competitive respect to LR. However many recent references [6][7][8] point out as this is true as long as the comparison considers the specific cost [$/kWe] of 1 LR respect 1 SMR. On the other hand, when the comparison is carried out considering the same power installed in the site (1340 MWe equivalent to 1 LR or 4 SMR) the result changes.…”

Appraisal of small modular nuclear reactors with ‘real options’ valuation

“…Carelli et al (2007Carelli et al ( , 2010 analyse specific factors, such as grid characteristics, construction time, financial exposition, modularisation and learning, which distinguish SMRs from LRs in the evaluation of capital cost. Once these factors are considered, the capital cost is comparable between the two technologies (Boarin et al, 2012;Carelli et al, 2008). Locatelli and Mancini (2011b) discuss the effects of 'non-financial parameters', such as electric grid vulnerability, public acceptance, risk associated with the project and others, on the evaluation of the best reactor size for an investment in the nuclear sector.…”

“…Several papers have discussed the competiveness of SMRs against large reactors (LRs) and how SMRs might balance the 'diseconomy of scale' with the 'economy of multiples' (Boarin et al, 2012Carelli et al, 2008;Locatelli and Mancini, 2012a;. Carelli et al (2007Carelli et al ( , 2010 analyse specific factors, such as grid characteristics, construction time, financial exposition, modularisation and learning, which distinguish SMRs from LRs in the evaluation of capital cost.…”