goingcritical:rancho-secoUnited States · Power reactor
Rancho Seco-1
Status: Shut down reached first criticality September 16, 1974 Reactor status full glossary → Announced Publicly announced — a site and design are proposed, but construction has not begun. Site preparation Early site and civil works are under way; the first safety-related ("nuclear") concrete has not yet been poured. Under construction Formal construction has begun, marked by the first nuclear concrete. Fuel loaded Nuclear fuel has been loaded into the core. The reactor is fuelled but has not yet gone critical. Critical Has reached first criticality — a self-sustaining chain reaction, usually at low power — but is not yet connected to the grid. Grid connected Synchronised to the electrical grid and exporting power for the first time, but still in commissioning and power-ascension testing — not yet in commercial service. In commercial operation — the operator has formally declared the unit in regular commercial service. Shut down Permanently shut down and no longer generating; may be defuelled, undergoing decommissioning, or preserved in place. Canceled Abandoned before completion.
Site: Herald, California
Closed in 1989 after a public ballot referendum — the first US reactor shut down by voter initiative
Details
| Design | Babcock & Wilcox PWR |
| Electrical output | 873 MWe |
Milestone history
- Announced —
- Construction start April 1, 1969
- Fuel load —
- First criticality September 16, 1974
- Grid connection October 13, 1974
- Commercial operation April 17, 1975