Business · Energy & Commodities · 1 hr ago
Darlington reactor project faces delay and cost overrun
Ontario Power Generation says the first reactor at Darlington will be delayed and cost more than planned.
The project is in Clarington, Ontario, beside the existing Darlington nuclear station, and includes plans for four small modular reactors.
The first unit is no longer expected to meet its October 2030 in-service target and will exceed its previously estimated cost of $7.7 billion; the size of the overrun has not been disclosed.
The full project budget is $20.9 billion, and construction began in late April with work on the reactor building and supporting infrastructure now under way.
The project is the first small modular reactor to begin construction in a G7 country, making its progress significant for other countries planning similar reactors.
OPG says it is assessing the schedule and costs and working on ways to limit the impact.
The assessment is expected to be completed by mid-2027, when OPG expects to provide a cost and schedule outlook.
Ontario Power Generation says the first reactor at the Darlington New Nuclear Project is no longer expected to meet its October 2030 in-service forecast.
The utility also says the first unit will exceed its previously disclosed estimated cost of $7.7-billion.
OPG is conducting a comprehensive assessment of the project’s schedule and costs, expected to be completed by mid-2027.
The project plans four small modular reactors beside the existing Darlington Nuclear Generating Station in Clarington, Ontario.
OPG cited ongoing engineering work and identified risks to the first unit’s schedule and budget; its reactor-design partner also pointed to other factors, including inflation and geopolitical risks.
- Who
- Ontario Power Generation (OPG), which is building the project with partners including GE Vernova Hitachi Nuclear Energy.
- What
- The first reactor is delayed against its October 2030 in-service forecast and will exceed its previously disclosed estimated cost.
- When
- OPG reported the update on Tuesday, November 10, 2026. Its assessment is expected to be completed by mid-2027.
- Where
- The Darlington Nuclear Generating Station site in Clarington, Ontario.
- Why
- OPG cited ongoing engineering work and risks to the unit’s schedule and budget. Its reactor-design partner also cited interconnected construction and procurement factors, inflation and geopolitical risks.
Ontario Power Generation
GE Vernova Hitachi Nuclear Energy
Aspect
Ontario Power Generation
OPG reported that the cost overruns reflected the partner’s ongoing engineering work.
GE Vernova Hitachi Nuclear Energy
GE Vernova Hitachi said there were multiple interconnected contributions, including factors outside its control.
Aspect
Ontario Power Generation
OPG said it had identified risks affecting Unit 1’s schedule and budget and was assessing their impacts.
GE Vernova Hitachi Nuclear Energy
GE Vernova Hitachi pointed to engineering, procurement and construction, as well as evolving market conditions, inflation and geopolitical risks.
Ontario supported the selection of the BWRX-300 for the Darlington project.
The project was expanded to four units.
Ontario authorized construction.
Construction of the first BWRX-300 officially began with installation of the reactor building foundation.
OPG reported that the first unit was no longer expected to meet its October 2030 in-service forecast and would exceed its previously disclosed estimated cost.
OPG expects to complete its assessment of the project’s schedule and costs.
- Project budget
- $20.9-billion
- First unit’s previous estimated cost
- $7.7-billion
- Planned reactors
- Four BWRX-300 small modular reactors
- Capacity per reactor
- 300 megawatts
- Project location
- Clarington, Ontario
- Assessment expected
- Mid-2027
What people are saying
We have identified risks that will impact Unit 1’s schedule and budget
there are multiple interconnected contributions across engineering, procurement and construction, as well as evolving market conditions, including inflation and geopolitical risks.