Table 6.11 presents the data on operation and maintenance (O&M) and fuel costs for some of the SMRs addressed in this report. For comparison, included are similar data for the representative large reactors from reference [6.1].

The O&M and fuel costs are directly available only for a few SMRs, while for the majority of SMRs only the LUEC and the overnight cost were available. Where possible, we inferred the data for O&M and fuel costs using the formula (6.1) and neglecting the decommissioning costs, for a limited number of PWR- and HTGR-type SMRs. This estimate cannot give the breakdown between O&M and fuel costs.

The data presented in Table 6.11 leads to the following observations:

• There is a considerable spread of data on O&M and fuel costs even for NPPs with large reactors presented in reference [6.1]. The corresponding sums of O&M and fuel costs vary from 16.9 to 25.8 USD/MWh.

• The sums of O&M and fuel costs for SMRs vary between 7.1 and 36.2 USD/MWh. Both of the values exceeding 30 USD/MWh belong to SMRs with a long refuelling interval:

— 36.2 USD/MWh belongs to the IRIS version with a 96-month refuelling interval; and

— 33.5 USD/MWh belongs to the ABV with a 144-month refuelling interval (see Table 4.1 in Section 4.2.1).

• In both cases the increase is probably linked with a less effective fuel utilisation associated with the long refuelling intervals. For SMRs with conventional refuelling intervals, the sums of O&M and fuel costs are between 7.1 and 26.7 USD/MWh, being basically within the range for the considered NPPs with large reactors.

• The example of VBER-300 indicates that the sum of O&M and fuel costs for a barge — mounted reactor is ~50 % higher compared to the land-based one. As already mentioned, this could be explained by a larger volume of the O&M essentially required for the barge. In particular, the barge is assumed to be towed to the factory each ~12 years to undergo factory repair and maintenance.

The designers of advanced SMRs often indicate that O&M costs could be lower than those of large reactors owing to a stronger reliance of SMRs on inherent and passive safety features and to the resulting decrease in the number and complexity of safety systems [6.2, 6.8].

Regarding the fuel costs, SMRs generally offer lower degree of fuel utilisation compared to the state-of-the art large reactors, mainly because of the poor neutron economy due to small reactor core [6.2, 6.8]. Lower degrees of fuel utilisation result in higher fuel costs[53], which is most sharply manifested for SMRs with long refuelling interval, e. g., the ABV or the IRIS with a long refuelling interval (see Table 6.11).