XA9744505 IAEA-SM-346/24p

Economic Comparison of 'MOX fuel cycle' with ' fuel cycle'

Ki-Dong Song, Man-Ki Lee, Kee-Hwan Moon, and Seung-Su Kim Economic Analysis Department, Korea Atomic Research Institute, Taejon, Korea

This study compares the economics of 'MOX fuel cycle' (MFC) with 'Uranium fuel cycle' (UFC). Figure 1 shows the concept of MFC and UFC. As shown in Figure 1, MFC is linked with both 'Reactor-A' (RA) and 'Reactor-C (RC). MOX fuel loaded in RC is manufactured by mixture of extracted from the spent fuel of RA with . The RA and 'Reactor-B' (RB) consist of two independent UFC, assuming that RB uses the same fuel type as RA. It is also assumed that RB and RC are the same PWR types as well as their commercial operation start at the same date in order to compare two different fuel cycle cost more consistently. Finally, it is also assumed that amount of the loaded fuels for both RB and RC are to be identical.

hi Reactor-A S/F Fabricattion Disposal • Enrichment S/F Storage U3O8

• f •- • % • Conversion Reprocessing y Conversion Reprocessing r Waste T Disposal Kb MOX Enrichment U3O8 Fabrication i Depleted Fabrication Uranium r T ReactorsC Reactor-B t t y S/F Storage S/F Storage C ommercial Operation Da te of Reactor-B and Reactor—C T S/F Disposal S/F Disposal < Common Cycle Related MOX & U Fuel Cycle > < MOX Fuel Cycle > < U Fuel Cycle >

Figure 1 Concepts of MOX fuel cycle and U fuel cycle The component costs of front-end fuel cycle such as U3O8, conversion, enrichment, and fabrication are estimated on the basis of data from Korea Electric Power Corporation (KEPCO). In fact, KEPCO is owned by the government and this data is officially used in long-term electric system expansion planning in Korea. The back-end component costs except for disposal cost of spent fuel are based on OECD/NEA report [2]. The disposal cost is estimated as 542,000 Won/kgU (equivalents 700$/kgU) which is being actually accumulated every year by KEPCO. And it is also assumed that the disposal cost and storage cost of spent fuel of UFC and MFC have the same values. and lag times in Table-1 are accumulated figures when the timing of fuel loading of RA is assumed as the base date, that is, 'O(zero)'. Loss rates of conversion, fabrication, reprocessing, and MOX fuel fabrication are assumed to be 0.5%, 1.0%, 2.0%, and 1.0%, respectively. Discount rate is assumed to be 8.0%, which is used by KEPCO. All costs are expressed in constant dollars in the year of 1996. Table-2 shows the results of economic comparison of MFC with UFC. As shown in this table, levelized fuel cycle cost of MFC and UFC is 6.78 and 6.34 mills/kwh, respectively. Economic inferiority of MFC is mainly stemming from high reprocessing cost. Sensitivity analyses were carried out to see the effects of the change in some critical input parameters such as uranium price, reprocessing, and MOX fabrication costs on the levelized fuel cycle costs. According to the sensitivity analysis, if the uranium price rises over $335/kgU(=$129/lb U3O8), MFC is economically more competitive than UFC. On the other hand, if MOX fabrication costs and reprocessing costs each fall by 20%, the break-even point for both MFC and UFC occurs at the uranium price of $167.4/kgU(=$64.4/lb U3O8), while MFC is economically more competitive than UFC at the range of a higher uranium price than the above. Finally, if MOX fabrication costs and reprocessing costs fall by 33% each, MFC is economically more competitive than UFC.

84 Table-1 Major input data for economic comparison between MFC and UFC alternative Cost Data Lead & Lag Loss Rate Fuel cycle component Unit Cost Time (months) (%) U3O8 S/kgU 64.4 -24 Conversion ykgU 5.6 -18 0.5 Enrichment S/SWU 133 -12 Reactor-A Fabrication VkgU 297 -6 1.0 Spent fuel transport/interim storage $/kgHM 269 +60 Spent fuel disposal $/kgHM 700 +300 U3O8 $/kgU 64.4 +72 Conversion $/kgU 5.6 +78 0.5 Enrichment 133 +84 Reactor-B $/swu Fabrication $/kgU 297 +90 1.0 Spent fuel transport/interim storage $/kgHM 269 +156 Spent fuel disposal $/kgHM 700 +396 ^Reprocessing $/kgHM 843 +72 2.0 MOX fabrication S/kgHM 937 +90 1.0 Reactor-C Reprocessing waste disposal $/kgHM 700 +312 MOX Spent fuel transport/interim storage S/kgHM 269 +156 MOX spent fuel disposal S/kgHM 700 +396 O Burnup : 43,000 MWD/MTU 0 Enrichment : 3.7 % Technical Data o in core residence times •" 4yrs o Talis assay •' 0.225% o Discount rate = 8.0 %/yr o Exchange rate : 774.7 Won/$ General Data o Cost reference year = 1996. 1. 1 Notes 1) Base date of lead and lag time is the loading date on Reactor-A (not included in in-core residence times) 2) UFC = Reactor-A + Reactor-B, MFC = Reactor-A + Reactor-C

Table-2 Results of economic evaluation on UFC and MFC alternative Fuel cycle cost (mills/kWh) Fuel cycle component Uranium fuel cvcle MOX fuel cvcle U3O8-A 1.72 1.72 Conversion-A 0.14 0.14 Common cycle Enrichment-A Z52 2.52 Fabrication-A 0.97 0.97 Spent fuel storage-A 0.40 - Spent fuel disposal-A 0.22 - U3O8-B 0.11 - Conversion-B 0.01 - Uranium fuel cycle Enrichment-B 0.15 - Fabrication-B 0.06 - Spent fuel storaoe-B 0.02 - Spent fuel disposal-B 0.01 - Reprocessing-C - 1.16 Reprocessing waste disposal-C - 0.19 MOX fuel cycle MOX fabrication-C - 0.04 Spent fuel storage-C - 0.03 Spent fuel disposal-C - 0.01 Total fuel cycle cost 6.34 6.78 Relative cost index (%) 100 107 Notes) A, B and C mean independent PWR type Plant.

References [ 1 ] OECD/NEA, Plutonium Fuel An Assessment, 1989. [ 2 ] OECD/NEA, The Economics of the Cycle, 1993. [ 3 ] KEPCO, Economic Comparison by Each Power Supply Options, 1993. 7.

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