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Pickering nuclear power plant A4

Retired Canada
Gross capacity
542MW

Pickering nuclear power plant A4 is a pressurised heavy water reactor unit at Pickering nuclear power plant in Canada rated at 542 MW gross. It is retired. Commercial operation began 17 Jun 1973.

Corrected against a later source

Permanently shut down on 31 December 2024, after the GNPT record was last researched in May 2024.

status: operating → retired · IAEA Power Reactor Information System, reactor record PICKERING-4 · verified 2026-09-06

Permanently shut down on 31 December 2024, after the GNPT record was last researched in May 2024.

permanent_shutdown: not set → 2024-12-31 · IAEA Power Reactor Information System, reactor record PICKERING-4 · verified 2026-09-06

Permanently shut down on 31 December 2024, after the GNPT record was last researched in May 2024.

retirement_year: not set → 2024 · IAEA Power Reactor Information System, reactor record PICKERING-4 · verified 2026-09-06

Specification
Reactor type Pressurised heavy water reactor (PHWR)
ModelCANDU 500A
Size classLarge
CoolantHeavy water
ModeratorHeavy water
Gross capacity542MW
Net capacity (reference)515MW
Net capacity (design)508MW
Thermal output1,744MWt
Typical enrichmentNatural uranium, 0.71% U-235
Ownership & location
SitePickering nuclear power plant
UnitA4
CountryCanada
OwnerOntario Power Generation Inc100%
OperatorOntario Power Generation
Coordinates 43.8107, -79.0689
Fuel chain for this unit
Fuel form
Natural uranium dioxide bundles
Enrichment
Natural uranium, 0.71% U-235 no enrichment required
Who makes this assembly
Upstream

This unit runs on natural uranium, so its fuel chain has no enrichment step at all: mine → mill → conversion → fabrication. That is the shortest fuel chain of any commercial reactor type, and it makes the operator independent of the four organisations that control enrichment worldwide.

Conversion
CamecoCNNCConverDynOranoRosatom
Fabricator capability is recorded against reactor type and model line, not against named units — utilities do not publish fuel contracts. See the fuel chain.

Timeline

  1. 1 May 1968Construction start
  2. 16 May 1973First criticality
  3. 21 May 1973Grid connection
  4. 17 Jun 1973Commercial operation
  5. 31 Dec 2024Permanent shutdown

Other units at Pickering nuclear power plant

UnitStatusGross MW
Pickering nuclear power plant A1 Retired 542
Pickering nuclear power plant A2 Retired 542
Pickering nuclear power plant A3 Retired 542
Pickering nuclear power plant B5 Operating 540
Pickering nuclear power plant B6 Operating 540
Pickering nuclear power plant B7 Operating 540
Pickering nuclear power plant B8 Operating 540

Other CANDU 500A units

4 units worldwide share this model designation.

UnitCountryStatusGross MW
Pickering nuclear power plant A1 Canada Retired 542
Pickering nuclear power plant A2 Canada Retired 542
Pickering nuclear power plant A3 Canada Retired 542

Sources