Reactor Status Timeline
Forced Outage · Day 1 NRC data, Mon to Fri ? Actual daily reactor status from NRC reports (Mon to Fri) and the current state. What is coming -- the utility's published Scheduled outage and NukeWorker's model Projection -- is part of a subscription. Colored by status. How far ahead you can see depends on your plan.OnlineReduced PowerCoastdownPower AscensionRefueling OutageForced Outage
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Composite Operational Excellence Score (0-100) — average percentile rank across 7 dimensions in three sub-scores: Reliability (capacity factor, forced outage days, B2B avg streak), Efficiency (fuel utilization, refuel duration), and Discipline (startup duration, scram count). 5-year window. Higher = more operationally excellent. Click to see the full breakdown.
Excellence
ranked of 93
Subscribers
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Days of continuous operation since the last outage ended. Has forced outage(s) since last refueling.
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Current Run
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Longest recorded period of continuous operation between outages (2018-11-20 to 2020-07-22).
610
Record Run
days
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Breaker-to-Breaker runs — continuous operation exceeding the cycle-adjusted threshold set for this unit with no trips to 0% power.
0
B2B Runs
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Lifetime capacity factor: average power level across all recorded days (100% = always at full power).
63.3%
Capacity Factor
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Net electricity actually generated over the most recent 12 months reported by the U.S. EIA (Form EIA-923), summed across every unit at this plant. Authoritative actuals, not an estimate.
30.96 TWh
Net Generation
EIA-923 · 12 mo to 2026-06 · plant total
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Total number of scheduled refueling outages detected in the historical data.
10
Outages
since 1999
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Average time from first power generation (>0%) to sustained full power (≥95% for 2+ days) across the last 3 scheduled outages. Click to compare against the fleet on the Operator Efficiency Leaderboard.
15.3
Avg Startup
days (last 3)
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Average fuel utilization — percent of the designed fuel cycle that this unit consumes before refueling, derived from the historical burn-down trajectory. Higher = more efficient operator (refuels with less margin remaining; closer to coastdown). Computed as 100% minus the unit's average refuel-point fuel %, using the last 3 years where available, otherwise lifetime average. Click to compare against the fleet on the Operator Efficiency Leaderboard.
100.0%
Fuel Utilization
3yr avg
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NukeWorker's Operational Excellence Score is a composite 0–100 ranking of every active US nuclear unit across 7 measured performance metrics, grouped into three sub-scores:
• Reliability — capacity factor, forced outage days, B2B avg streak
• Efficiency — fuel utilization, refuel duration
• Discipline — startup duration, scram count
Each unit's metric is converted to a percentile across the active fleet. Sub-score = average of its components; composite = average of the three sub-scores. Use the time-window toggle below to switch between 3yr / 5yr / lifetime.
• Reliability — capacity factor, forced outage days, B2B avg streak
• Efficiency — fuel utilization, refuel duration
• Discipline — startup duration, scram count
Each unit's metric is converted to a percentile across the active fleet. Sub-score = average of its components; composite = average of the three sub-scores. Use the time-window toggle below to switch between 3yr / 5yr / lifetime.
Time window
— change how far back we look
5-yr trend:
Stable vs 2025
Compare Browns Ferry 1 head-to-head with up to 3 other units.
Compare now
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Duration of each outage in days, shown chronologically. Green bars are scheduled refueling outages, red bars are forced/unscheduled. The orange dashed line marks the average duration. Extended outages (>180 days) and D&D periods are excluded.
Outage Duration Trend
Browns Ferry 1 has 38 outages plotted here, averaging 12 days each. The most recent, in Sep 2026, was a scheduled refueling outage lasting 6 days.
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Time in days from first power generation (>0%) to sustained full power (≥95% for 2+ consecutive days) after each scheduled refueling outage. The dashed line marks the average. Includes startup testing holds and power dips.
Startup Duration Trend
After a refueling outage, Browns Ferry 1 takes about 5 days to climb from first power back to full power. That average is drawn from 9 startups on record, and the most recent took 5 days.
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Monthly capacity factor with outage events overlaid as red bands. Green bars show average power level per month. Toggle to Daily view for raw daily data.
Power History
Over its operating life, Browns Ferry 1 has run at about 63.3% of its rated capacity. Across the last 12 reported months it averaged 94.5%. On the chart, flat stretches near the top are full-power running and drops to zero are outages.
This table logs every recorded outage for Browns Ferry 1, 39 in all since 1999. Of those, 10 were scheduled refueling outages, 1 was planned maintenance and 28 were unplanned or forced. The typical outage lasted about 90 days. Where the Scheduled column shows (Model), the date is a NukeWorker projection because the utility had not published one.
| Type ⇅ | Actual Start ⇅ | Actual End ⇅ | Duration ⇅ | Days Online ⇅ | Scheduled | Delta |
|---|---|---|---|---|---|---|
|
Scheduled
U1R16
|
2026-09-12 | In Outage | 6+ | 142d | 2026-09-11 | +1d |
|
Unscheduled
|
2026-04-18 | 2026-04-23 | 6 | 258d | - | - |
|
Scram
# 57847
|
2025-08-02 | 2025-08-03 | 2 | 72d | - | - |
|
Unscheduled
|
2025-05-20 | 2025-05-22 | 3 | 235d | - | - |
|
Scheduled
U1R15
|
2024-08-31 | 2024-09-27 | 28 | 117d | 2024-08-30 | +1d |
|
Scram
# 57090
|
2024-04-25 | 2024-05-06 | 12 | 86d | - | - |
|
Unscheduled
|
2024-01-26 | 2024-01-30 | 5 | 249d | - | - |
|
Scram
# 56531
|
2023-05-20 | 2023-05-22 | 3 | 108d | - | - |
|
Unscheduled
|
2023-01-31 | 2023-02-01 | 2 | 97d | - | - |
|
Scheduled
U1R14
|
2022-10-01 | 2022-10-26 | 26 | 251d | 2022-10-01 | 0d |
|
Unscheduled
|
2022-01-15 | 2022-01-23 | 9 | 435d | - | - |
| 2020-11-06 | 2020-11-06 | 1 | 2d | - | - | |
|
Scheduled
U1R13
|
2020-10-03 | 2020-11-04 | 33 | 66d | 2020-10-03 | 0d |
|
Scram
# 54795
|
2020-07-22 | 2020-07-29 | 8 | 610d | - | - |
|
Scheduled
U1R12
|
2018-10-14 | 2018-11-20 | 38 | 207d | 2018-10-13 | +1d |
|
Scram
# 53269
|
2018-03-19 | 2018-03-21 | 3 | 501d | - | - |
|
Scheduled
U1R11
|
2016-10-01 | 2016-11-03 | 34 | 61d | 2016-10-01 | 0d |
|
Unscheduled
|
2016-07-27 | 2016-08-01 | 6 | 250d | - | - |
|
Unscheduled
|
2015-11-16 | 2015-11-20 | 5 | 199d | - | - |
| 2015-04-30 | 2015-05-01 | 2 | 183d | - | - | |
|
Scheduled
U1R10
|
2014-10-04 | 2014-10-29 | 26 | 35d | 2014-10-04 | 0d |
|
Scram
# 50404
|
2014-08-27 | 2014-08-30 | 4 | 518d | - | - |
|
Scram
# 48829
|
2013-03-20 | 2013-03-27 | 8 | 110d | - | - |
|
Scheduled
U1R9
|
2012-10-20 | 2012-11-30 | 42 | 312d | 2012-10-22 | -2d |
|
Unscheduled
|
2011-12-10 | 2011-12-13 | 4 | 205d | - | - |
|
Scram
# 46793
|
2011-04-28 | 2011-05-19 | 22 | 156d | - | - |
|
Scheduled
U1R8
|
2010-10-24 | 2010-11-23 | 31 | 590d | 2010-10-25 | -1d |
|
Unscheduled
|
2009-02-26 | 2009-03-13 | 16 | 2d | - | - |
|
Unscheduled
|
2009-02-19 | 2009-02-24 | 6 | 81d | - | - |
|
Scheduled
U1R7
|
2008-10-26 | 2008-11-30 | 36 | 74d | 2008-10-24 | +2d |
|
Unscheduled
|
2008-08-09 | 2008-08-13 | 5 | 271d | - | - |
|
Unscheduled
|
2007-11-04 | 2007-11-12 | 9 | 19d | - | - |
|
Unscheduled
|
2007-10-13 | 2007-10-16 | 4 | 40d | - | - |
|
Unscheduled
|
2007-09-03 | 2007-09-03 | 1 | 21d | - | - |
|
Unscheduled
|
2007-08-12 | 2007-08-13 | 2 | 47d | - | - |
|
Unscheduled
|
2007-06-24 | 2007-06-26 | 3 | 12d | - | - |
|
Unscheduled
|
2007-06-10 | 2007-06-12 | 3 | 15d | - | - |
|
Unscheduled
|
2007-05-24 | 2007-05-26 | 3 | 2d | - | - |
| 1999-01-01 | 2007-05-22 | 3064 | - | - | - |
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