OPG, Aecon Sign C$3 Billion Contracts to Begin Pickering Nuclear Refurbishment

Ontario Power Generation has awarded contracts worth a combined C$3 billion to construction group Aecon for the first phase of the Pickering Nuclear Generating Station’s refurbishment, the companies said on September 21, 2026, as site work begins on a project intended to keep four reactors running for decades beyond their original design life. The awards mark the formal start of construction on a refurbishment OPG has previously priced at roughly C$26.8 billion across all four units.

Aecon’s 50/50 joint venture with AtkinsRéalis won a C$1.7 billion contract covering the Retube, Feeder and Boiler Replacement (RFBR) work on Unit 5 — the first of the four Pickering B units to be refurbished. The scope includes replacing the unit’s steam generators, fuel channels and feeder pipes, the components that most limit a CANDU reactor’s operating life. Separately, a consortium of Aecon and Siemens Energy secured a C$1.3 billion contract for Turbine Generator Replacement (TGR), covering 14 new steam turbine rotors and an overhaul of all four generators, including stator rewinds, plus new auxiliary systems. Aecon said its own share of the combined contracts, about C$1.75 billion, was added to its construction backlog in the third quarter of 2026.

One Unit First, Three More to Follow

The RFBR contract awarded now covers Unit 5 only. OPG and Aecon said similar retube and boiler-replacement work is anticipated for Units 6, 7 and 8 in subsequent phases, but those follow-on contracts are contingent on regulatory approval rather than already secured. Pickering B’s four units are being taken out of service by the end of September 2026 to allow refurbishment work to begin, and the reactor-level work itself still requires a construction authorization from the Canadian Nuclear Safety Commission, which OPG expects to receive in January 2027. Until then, site preparation, engineering and early infrastructure work can proceed, but the core retubing has not started.

Why Pickering Is Being Extended, Not Retired

Pickering, which began commercial operation in the 1970s, was for years slated for shutdown rather than refurbishment. OPG’s decision to instead rebuild four of its units reflects Ontario’s tightening electricity supply outlook, as the province’s grid operator has pointed to rising demand from electrification, data centers and industrial growth as reasons to keep existing baseload nuclear capacity in service rather than retire it on the original schedule. The refurbishment follows a similar model to OPG’s ongoing work at the Darlington station and Bruce Power’s multi-unit refurbishment program on Lake Huron, both part of a broader Ontario strategy to lean on nuclear power for the bulk of the province’s non-emitting electricity supply.

Scope Still to Come

Across all four Pickering B units, OPG’s refurbishment plan calls for replacing roughly 1,520 fuel channels and 48 boilers in total, along with construction of a new 1.5-kilometer deep-water cooling intake — figures that describe the full four-unit scope rather than the Unit 5 contracts announced this week. Neither OPG nor Aecon has yet disclosed contract values for the Unit 6, 7 and 8 RFBR work, which will depend on how the Unit 5 refurbishment performs on cost and schedule once it gets underway.

Sources

• Aecon Group Inc., press release via BNN Bloomberg, “Aecon teams awarded contracts with aggregate value of $3 billion for the Pickering Nuclear Generating Station Refurbishment”, September 21, 2026 — contract values, scope breakdown, JV/consortium structure
• World Nuclear News, “Contracts announced as Pickering refurb approaches”, September 2026 — unit sequencing, CNSC approval timeline
• ReNew Canada, “Pickering Refurbishment project underway with awarding of $3B in contracts” — total program cost context
• Ontario Construction News, “Pickering nuclear refurbishment moves into construction phase” — outage timing for Units 5-8

Illustrative image. Photo: Fischer.H, CC BY-SA 4.0, via Wikimedia Commons — source