Breaker-to-Breaker Runs
9 runs
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Breaker-to-breaker runs measure continuous operation between refueling outages using a cycle-adjusted threshold (90% of cycle length minus RFO duration). An active streak means the unit has been running continuously since the last refueling with no trips to 0% power.
North Anna 1 has logged 9 breaker-to-breaker runs, continuous stretches from one refueling to the next with no trip to zero power. Its longest ran 530 days, and its runs average 504 days.
530
Best Run (days)
1R27 (2019-10-01) → 1R28 (2021-03-14)
★ Quadruple breaker-to-breaker
1R24 → 1R25 → 1R26 → 1R27 → 1R28
All Runs
| 2024-06-01 |
2025-09-07 |
463 days |
1R30 → 1R31 |
| 2019-10-01 |
2021-03-14 |
530 days |
1R27 → 1R28 |
| 2018-04-16 |
2019-09-08 |
510 days |
1R26 → 1R27 |
| 2016-10-16 |
2018-03-11 |
511 days |
1R25 → 1R26 |
| 2015-04-05 |
2016-09-11 |
525 days |
1R24 → 1R25 |
| 2012-05-01 |
2013-09-08 |
495 days |
1R22 → 1R23 |
| 2007-10-15 |
2009-03-08 |
510 days |
1R19 → 1R20 |
| 2001-10-10 |
2003-02-23 |
501 days |
1R15 → 1R16 |
| 2000-05-10 |
2001-09-09 |
487 days |
1R14 → 1R15 |
About This Site
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Written by NukeWorker from public records: facts that do not change. Operator, status and capacity come from the live data elsewhere on this page. Sources: Wikipedia: North Anna Nuclear Generating Station.
North Anna Nuclear Generating Station is in Louisa County, Virginia, near Mineral, on a 1,075-acre site. Lake Anna, an artificial lake on the North Anna River, supplies its cooling water.
Read more
Construction began on February 19, 1971. Both units are Westinghouse three-loop pressurized water reactors. Unit 1 connected to the grid on April 19, 1978, and Unit 2 on August 25, 1980. Two further units were planned: North Anna 4 was cancelled in November 1980 and North Anna 3 in November 1982. On August 23, 2011, a magnitude 5.8 earthquake centered near Mineral automatically shut down both reactors and caused a loss of offsite power. Both units were back at full power by December 20, 2011.
Facility Statistics
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Key performance and lifecycle metrics calculated from NRC operational data. Includes operating age, construction timeline, capacity factor, efficiency, generation totals, and reliability records.
North Anna 1 has operated for about 48.4 years and averaged a 91.2% lifetime capacity factor, generating roughly 208.2 TWh of electricity. Its longest unbroken run reached 533 days.
Lifecycle & Tenure
Operating Age: 48.4 Yrs
Build Time: 7.3 Yrs
Lic. Remaining: 31.4 Yrs
Production & Power
Lifetime CF: 91.2%
Efficiency: 32.2%
Generated: 208.2 TWh
Reliability & Outages
Record Run: 533 Days
Refuelings: 18
Avg Startup: 4.2 Days
Ownership & Construction
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The utility or company that owns and operates the facility, the architect-engineer responsible for plant design, and the primary construction contractor. Click names to view all facilities by that entity on the map.
Ownership, operation and management history
No change of owner, operator or management company on record. Our history starts in 1999.
D
Dominion Energy, Inc.
NYSE
$62.42
▼ -0.42 (-0.66%)
Previous Close
62.84
Day's Range
62.26 – 63.50
52-Week Range
55.85 – 72.99
Volume
3,206,980
Dominion Energy and NextEra Energy (NEE) announced a merger on 2026-05-18. It is still subject to regulatory and shareholder approval, so Dominion remains the owner of record here until the deal closes.
Operational Excellence Score Subscribers
North Anna 1 is rated 0 to 100 on how well it actually runs, scored against every other operating reactor in the US fleet from its own operating record. Subscribers see the score, the three sub-scores behind it, and each of the seven measured inputs.
- This unit's composite score and fleet rank
- Reliability, Efficiency and Discipline sub-scores
- All seven measured inputs, with fleet percentiles
- Rank against comparable units, not just the fleet
- Three-year, five-year and lifetime windows
- Five-year trend, and every other operating US reactor
Scram History
8 events since 2011
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Automatic and manual reactor scram (emergency shutdown) events reported to the NRC since 2011. Includes event dates, trip type, and average recovery time. Click the title to view the full fleet scram dashboard.
North Anna 1 has recorded 8 reactor scrams, or emergency shutdowns, since 2011 (6 automatic, 2 manual). On average the unit was back to full power about 10 days after each trip.
Recent Events
| 2025-10-21 |
Auto |
AUTOMATIC REACTOR TRIP The following information was provide... |
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| 2024-05-29 |
Auto |
AUTOMATIC REACTOR TRIP The following information was provide... |
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| 2022-04-14 |
Auto |
AUTOMATIC REACTOR TRIP DURING CONTROL ROD TESTING The follow... |
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| 2021-05-06 |
Manual |
EN Revision Imported Date: 6/4/2021 EN Revision Text: MANUAL... |
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| 2015-04-02 |
Manual |
MANUAL REACTOR TRIP DUE TO MAIN GENERATOR VOLTAGE REGULATOR ... |
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| 2015-02-26 |
Auto |
AUTOMATIC REACTOR TRIP DUE TO FEEDWATER REGULATING VALVE FAI... |
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| 2013-10-11 |
Auto |
AUTOMATIC TURBINE AND REACTOR TRIP DUE TO STATION SERVICE TR... |
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| 2011-08-23 |
Auto |
ALERT DECLARED DUE TO AN EARTHQUAKE IN THE AREA AND A LOSS O... |
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Technical Specs
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Reactor design specifications including type (PWR/BWR), containment design, nuclear steam supply system manufacturer, thermal and electrical power ratings, and current operational status.
Turbine Supplier:
WESTINGHOUSE ELECTRIC CORPORATION IAEA
Thermal Power:
2940 MWt
Net Capacity:
948 MWe
Gross Capacity:
990 MWe IAEA
Design Capacity:
907 MWe IAEA
Efficiency:
32.2%
Lifetime Output:
320.3 TWh through 2025 IAEA
Licensing
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NRC licensing history including docket number, license type and number, construction permit date, operating license issuance, commercial operation date, license renewal, and expiration date.
Docket #:
05000338
License #:
NPF-4
License Type:
OL-FP
Const. Permit:
1971-02-19
Construction Start:
1971-02-19 IAEA
Operating Lic:
1978-04-01
First Criticality:
1978-04-05 IAEA
Grid Connection:
1978-04-17 IAEA
Commercial Op:
1978-06-06
License Renewed:
2024-08-28
License Exp:
2058-04-01
Market & Region
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EIA market and grid-region classifications: NERC reliability region, U.S. Census region, balancing authority responsible for grid operations, and whether the unit operates as a rate-regulated utility or a competitive merchant generator. Hover any value for the full name.
NERC Region:
SERC
— SERC Reliability Corporation
Census Region:
SAT
— South Atlantic
Balancing Authority:
PJM
— PJM Interconnection (ISO/RTO)
Market Structure:
Regulated
— Rate-regulated utility (cost-of-service pricing)