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Cost methodology and drivers employed in the cost equations for single cost items_
| EEDB Account No. | Account descriptions | Cost item category | Cost estimation methodology | Drivers |
|---|---|---|---|---|
| 212 | Reactor containment building | HH | − Scaling factor | − Concrete volume |
| − Analytic estimate | − Structural steel weight | |||
| − Factorial estimate | − Excavation volume | |||
| − NPP electrical output | ||||
| 213 | Turbine room and heater bay | HH | − Scaling factor | − Concrete volume |
| − Analytic estimate | − Structural steel weight | |||
| − Factorial estimate | − Excavation volume | |||
| − NPP electrical output | ||||
| 218 | Other structures | HH | − Scaling factor | − NPP electrical output |
| − Configuration of NPP buildings | ||||
| 222 | Main heat transfer transport system | HH | − Factorial estimate | − Tube and collectors weight |
| − Analytic estimate | − Pipe flow rate | |||
| − Steam generators shape | ||||
| − Circulation system of primary reactor coolant | ||||
| 223 | Safeguards system | HH | − Expert judgement | − Passive safety system configuration and components |
| − Factorial estimate | ||||
| 226 | Other reactor plant equipment | HH | − Scaling factor | − NPP electrical output |
| 233 | Condensing systems | HH | − Scaling factor | − Reactor thermal output |
| − Condensing system characteristics | ||||
| 235 | Other turbine plant equipment | HH | − Factorial estimate | − Turbine generator cost |
| 245 | Electric structure and wiring | HH | − Scaling factor | − NPP electrical output |
| − Safety system configuration | ||||
| 252 | Air water and steam service systems | HH | − Scaling factor | − NPP electrical output |
| − Configuration of NPP buildings | ||||
| 211 | Yard work | HL | − Analytic estimate | − NPP footprint |
| 221 | Reactor equipment | HL | − Factorial estimate | − Reactor weight |
| − Analytic estimate | − Reactor pressure vessel diameter size | |||
| − Integration of the nozzle in the forged part | ||||
| − Number of control rods | ||||
| 227 | Reactor instrumentation and control | HL | − Expert judgement | − Passive safety system configuration and components |
| − Factorial estimate | ||||
| 231 | Turbine generator | HL | − Scaling factor | − NPP electrical output |
| − Turbine equipment characteristics | ||||
| 234 | Feedwater heating system | HL | − Scaling factor | − Reactor thermal output |
| − Feedwater heating system characteristics | ||||
| 262 | Mechanical equipment | HL | − Scaling factor | − Reactor thermal output |
| − Condensing system characteristics | ||||
| 224 | Radwaste processing | LH | − Scaling factor | − NPP electrical output |
| 246 | Power and control wiring | LH | − Scaling factor | − NPP electrical output |
| 214 | Security building | LL | − Scaling factor | − NPP electrical output |
| 215 | Primary auxiliary building and tunnels | LL | − Scaling factor | − Concrete volume |
| − Analytic estimate | − Structural steel weight | |||
| − Factorial estimate | − Excavation volume | |||
| − NPP electrical output | ||||
| 216 | Waste processing building | LL | − Scaling factor | − Concrete volume |
| − Analytic estimate | − Structural steel weight | |||
| − Factorial estimate | − Excavation volume | |||
| − NPP electrical output | ||||
| 217 | Fuel storage building | LL | − Scaling factor | − Concrete volume |
| − Analytic estimate | − Structural steel weight | |||
| − Factorial estimate | − Excavation volume | |||
| − NPP electrical output | ||||
| 225 | Fuel handling and storage | LL | − Scaling factor | − NPP electrical output |
| 228 | Reactor plant miscellaneous items | LL | − Scaling factor | − NPP electrical output |
| 236 | Instrumentation and control | LL | − Scaling factor | − NPP electrical output |
| 237 | Turbine plant miscellaneous items | LL | − Scaling factor | − NPP electrical output |
| 241 | Switchgear | LL | − Scaling factor | − NPP electrical output |
| 242 | Station service equipment | LL | − Scaling factor | − Electrical system class |
| − NPP electrical output | ||||
| − Electrical system class | ||||
| − Safety system configuration | ||||
| 243 | Switchboard | LL | − Scaling factor | − NPP electrical output |
| − Electrical system class | ||||
| 244 | Protective equipment | LL | − Scaling factor | − NPP electrical output |
| 251 | Transportation and lifting equipment | LL | − Scaling factor | − NPP electrical output |
| 253 | Communications equipment | LL | − Scaling factor | − NPP electrical output |
| 254 | Furnishings and fixture | LL | − Scaling factor | − NPP electrical output |
| 255 | Wastewater treatment equipment | LL | − Scaling factor | − NPP electrical output |
| 261 | Structures | LL | − Scaling factor | − NPP electrical output |
Cost items included in each class_
| EEDB Account No. | Account descriptions | Class 1 – main cost items | Class 2 – critical cost items | Cost item category |
|---|---|---|---|---|
| 212 | Reactor containment building | A | A | HH |
| 226 | Other reactor plant equipment | A | A | HH |
| 245 | Electric structure and wiring | A | A | HH |
| 218 | Other structures | A | A | HH |
| 252 | Air water and steam service systems | A | A | HH |
| 235 | Other turbine plant equipment | A | A | HH |
| 213 | Turbine room and heater bay | A | A | HH |
| 223 | Safeguards system | A | A | HH |
| 222 | Main heat transfer transport system | A | A | HH |
| 233 | Condensing systems | A | A | HH |
| 234 | Feedwater heating system | A | B | HL |
| 211 | Yard work | A | B | HL |
| 262 | Mechanical equipment | A | B | HL |
| 231 | Turbine generator | A | B | HL |
| 227 | Reactor instrumentation and control | A | C | HL |
| 221 | Reactor equipment | A | C | HL |
| 246 | Power and control wiring | B | A | LH |
| 224 | Radwaste processing | B | A | LH |
| 215 | Primary auxiliary building and tunnels | B | B | LL |
| 216 | Waste processing building | B | B | LL |
| 217 | Fuel storage building | B | C | LL |
| 228 | Reactor plant miscellaneous items | C | C | LL |
| 237 | Turbine plant miscellaneous items | C | C | LL |
| 261 | Structures | C | C | LL |
| 236 | Instrumentation and control | C | C | LL |
| 225 | Fuel handling and storage | B | C | LL |
| 253 | Communications equipment | C | C | LL |
| 244 | Protective equipment | C | C | LL |
| 214 | Security building | C | C | LL |
| 251 | Transportation and lifting equipment | C | C | LL |
| 255 | Wastewater treatment equipment | C | C | LL |
| 254 | Furnishings and fixture | C | C | LL |
| 242 | Station service equipment | B | C | LL |
| 243 | Switchboard | C | C | LL |
| 241 | Switchgear | B | C | LL |
SMRs cost factors, components and value/impact identification_
| Factors | Components | Impact and value |
|---|---|---|
| Economy of scale (*) | Structures, components, labour | Baseline cost |
| Economy of replication; learning (*) | Site labour, site material, learning rates | Future cost |
| Modularisation (*) | Factory building cost, efficiency of work moved outside, efficiency in the serial fabrication of components. | Baseline cost, project duration |
| Plant design (*) | Plant simplification rate (progressive construction/operation of multiple modules); active and passive safety; multiple units at single site. | Baseline cost |
| Project management related risks | Overnight cost; construction methods; regulatory risks; labour hours; integration risks; offsite work. | Time and budget overrun |
Indirect cost modelling assumptions_
| Base scaling relation | Base scaling value (%) | Escalation relation | |
|---|---|---|---|
| Site labour cost | PWR12 BE indirect site labor cost | 36 | |
| PWR12 BE direct site labor cost | |||
| Site material cost | PWR12 BE indirect site material cost | 79 | New plant average # workers |
| PWR12 BE direct site material cost | PWR12 BE average # workers | ||
| Factory equipment cost | PWR12 BE indirect factory cost | 132 | New plant construction time |
| PWR12 BE direct site labor cost | PWR12 BE construction time |
Overview of the number of cost items estimated for each accuracy class_
| Accuracy class | Direct cost IRIS NOAK(%) | Weight over total direct cost (%) | Number of 3rd level COA voices per category | Percentage of 3rd level COA voices per category (%) | Number of cost item estimated per category (# of computation) | Percentage of cost item estimated per category (%) |
|---|---|---|---|---|---|---|
| 3 (-20%; +30%) | 43.71 | 44 | 10 | 29 | 24 | 14.46 |
| 3/4 (-25%; +40%) | 10.90 | 11 | 1 | 3 | 19 | 11.45 |
| 4 (-30%; +50%) | 12.98 | 13 | 6 | 17 | 42 | 25.30 |
| 5 (-50%; +100%) | 32.41 | 32 | 18 | 51 | 81 | 48.80 |
| Total | 100.00 | 35 | 166 |
OCC and capital cost SMRs and PWR12 (2019 and 2023 EUR)_
| OCC | Capital cost | |||||||
|---|---|---|---|---|---|---|---|---|
| IRIS single | IRIS twin | NuScale | PWR12 | IRIS single | IRIS twin | NuScale | ||
| 2019 | NOAK (%) | 87 | 75 | 85 | 81 | 114 | 101 | 116 |
| FOAK (%) | 132 | 112 | 136 | 140 | 228 | 199 | 247 | |
| 2023 | NOAK (%) | 108 | 94 | 105 | 100 | 142 | 126 | 144 |
| FOAK (%) | 163 | 138 | 167 | 174 | 281 | 245 | 304 | |
Benchmarking comparison of IRIS NOAK (2 × 335 MWe) with the two AP1000s (2 × 1078 MWe)_
| AP1000 (2 × 1078 MWe) | PWR12-BE (1144 MWe) | IRIS single conf. (2 × 335 MWe) | IRIS twin conf. (2 × 335 MWe) | |
|---|---|---|---|---|
| Civil/structural/architectural component (%) | 24 | 22 | 17 | 16 |
| Mechanical component (%) | 65 | 69 | 69 | 73 |
| Electrical component (%) | 11 | 9 | 13 | 11 |
| Direct cost (%) | 100 | 100 | 100 | 100 |
| OCC/kWe (US$-2023) | 3.600 | 4.084 (ref. case) | 4.391 | 3.824 |
Benchmarking comparison of NuScale NOAK (12 × 77 MWe) with the 12-unit SMR-based NPP_
| Costs include contingency | SMR (12 × 50 MWe) | PWR12-BE (1,144 MWe) | NuScale (12 × 77 MWe) |
|---|---|---|---|
| Civil/structural/architectural subtotal (%) | 25 | 22 | 14 |
| Mechanical subtotal (%) | 64 | 69 | 74 |
| Electrical subtotal (%) | 11 | 9 | 12 |
| Direct costs (%) | 100 | 100 | 100 |
Comparison between recent NuScale estimates and our results_
| Source | Specific Cost (US$/kWe) | Cost type | Units | NPP power (MWe) | Construction experience | Reactor | Year | Normalised cost (US$2023 – 924 MWe) |
|---|---|---|---|---|---|---|---|---|
| Stewart and Shirvan (2022) | 3,856 | OCC | 12 | 684 | 10th OAK | NuScale iPWR | 2018 | 4,239 |
| Stewart and Shirvan (2022) | 6,554 | OCC | 12 | 684 | FOAK | NuScale iPWR | 2018 | 7,206 |
| US Department of Energy (2018) | 8,936 | OCC | 6 | 480 | - | Generic | 2023 | 6,877 |
| NuScale and the Utah Associated Municipal Power Systems | 20,139 | Capital Cost | 6 | 462 | FOAK | NuScale iPWR | 2022 | 16,178 |
| This work | - | OCC | 12 | 924 | NOAK | NuScale | 2023 | 4,304 |
| This work | - | Capital Cost | 12 | 924 | NOAK | NuScale | 2023 | 5,872 |
| This work | - | OCC | 12 | 924 | FOAK | NuScale | 2023 | 6,81 |
| This work | - | Capital Cost | 12 | 924 | FOAK | NuScale | 2023 | 12,397 |
Average estimation accuracy value per category_
| Cost item cost over total direct cost | High | HL | HH |
| Low | LL | LH | |
| Low | High | ||
| Cost item variation weight over total direct cost variation | |||
Adjusting factors employed in the cost analysis_
| EEDB Account No. | Account descriptions | Max cost adjusting factors | |
|---|---|---|---|
| Site labour | Equipment and site material | ||
| 21 | Structures and improvements subtotal | 1.68 | 1.30 |
| 22 | Reactor plant equipment | 2.16 | 1.04 |
| 23 | Turbine plant equipment | 1.82 | 1.05 |
| 24 | Electric plant equipment | 1.93 | 1.12 |
| 25 | Miscellaneous plant equipment | 1.94 | 1.11 |
| 26 | Main condenser heat rejection system | 1.41 | 1.04 |
Adapted from Carelli et al_ (2010)_ SMR ad hoc and common factors influencing their economics_
| SMR ad hoc (specific) factors | Common factors |
|---|---|
| • Design-related characteristics | • Size |
| • Compactness | • Modularisation |
| • Cogeneration | • Factory fabrication |
| • Match of supply to demand | • Multiple units at a single site |
| • Reduction in planning margin | • Learning |
| • Grid stability | • Construction time |
| • Economy of replication | • Required front end investment |
| • Bulk ordering | • Progressive construction/operation of multiple modules |
| • Serial fabrication of components |
Summary of the interviewed organisations, their main business areas and the professional roles of participants involved in the data collection phase_
| Type of organisation | Main business area | Interviewee roles | Number of participants |
|---|---|---|---|
| Large energy engineering firm | Design and manufacturing of turbines, heat exchangers and steam generators | Head of Cost Engineering; Senior Process Engineer; Procurement Specialist | 6 |
| Medium-sized mechanical manufacturer | Pressure vessels, reactor containment components, modular assembly | Technical Director; Manufacturing Supervisor; Quality Assurance Manager | 7 |
| Construction and civil infrastructure contractor | Nuclear civil works, modular foundations, site integration | Project Manager; Site Cost Controller; Construction Engineer | 5 |