Comanche Peak 1 - Status & History

Comprehensive reactor performance metrics, cycle analysis, and historical outage data.
Data refreshed 13.3h ago Rx Status: Sep 10, 2026 at 5:21 AM (M-F)

Reactor Status Timeline

Online 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.
Oct2025NovDecJan2026FebMarAprMayJunJulAugSepOnline: Sep 10, 2025 to Sep 24, 2025Scram: Sep 25, 2025 to Sep 26, 2025Reduced Power: Sep 27, 2025Online: Sep 28, 2025 to Aug 22, 2026Reduced Power: Aug 23, 2026 to Aug 24, 2026Online: Aug 25, 2026 to Sep 10, 2026Scram (reactor trip): Sep 24, 2025Today
OnlineReduced PowerScramScram (reactor trip)
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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 (Started 2025-09-26). Clean run (no forced outages since last refueling).
349
Current Run
days ✔
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Longest recorded period of continuous operation between outages (2017-11-06 to 2019-04-22).
532
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.
8
B2B Runs
76% toward B2B (347/458d)
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Lifetime capacity factor: average power level across all recorded days (100% = always at full power).
92.7%
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.
20.02 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.
18
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.
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.
99.5%
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.
Time window — change how far back we look
5-yr trend: 2021: 71/100 (#20/93)2022: 56/100 (#39/92)2023: 47/100 (#50/92)2024: 53/100 (#39/92)2025: 50/100 (#46/92)2026: 50/100 (#41/93) Stable vs 2025
Compare Comanche Peak 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

Comanche Peak 1 has 37 outages plotted here, averaging 18 days each. The most recent, in Sep 2025, was a unplanned outage lasting 2 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, Comanche Peak 1 takes about 4 days to climb from first power back to full power. That average is drawn from 18 startups on record, and the most recent took 2 days.
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Estimated fuel remaining in the current cycle, expressed as a percentage of the unit's typical cycle. Starts at 100% when the unit returns to power post-refuel and drops as full-power-days are burned. Days at reduced power burn fuel proportionally — so a unit with significant downtime (high burn deficit) drops slower and ends up with MORE fuel left than its calendar position would suggest. Coastdown threshold around 15%. Toggle to overlay past cycles on a normalized "days into cycle" axis to see how aggressively this unit historically burns down before refuel.

Fuel Burn Down Cycle since May 15, 2025

7.5% remaining 3.8 FPD margin
Comanche Peak 1 has an estimated 7.5% of its fuel left. Across its last 17 cycles, it has refueled with an average of 2.4% remaining.
Avg refuel: 2.4% Avg refuel (3yr): 0.5% Deepest burn: 0.0% (2007-04 → 2008-09) Most margin: 10.7% (2002-11 → 2004-03)
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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, Comanche Peak 1 has run at about 92.7% of its rated capacity. Across the last 12 reported months it averaged 99.8%. 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 Comanche Peak 1, 37 in all since 1999. Of those, 18 were scheduled refueling outages and 19 were unplanned or forced. The typical outage lasted about 18 days. Where the Scheduled column shows (Model), the date is a NukeWorker projection because the utility had not published one.
Scram # 57950
2025-09-25 2025-09-26 2 134d - -
Scheduled 1RF24
2025-04-21 2025-05-14 24 340d 2025-04-17 +4d
Unscheduled
2024-05-11 2024-05-16 6 180d - -
Scheduled 1RF23
2023-10-16 2023-11-13 29 121d 2023-10-15 +1d
Scram # 56580
2023-06-17 2023-06-17 1 278d - -
Scram # 56091
2022-09-06 2022-09-12 7 115d - -
Scheduled 1RF22
2022-04-11 2022-05-14 34 519d 2022-04-20 -9d
Unscheduled Startup Hold
2020-11-07 2020-11-08 2 2d - -
Scheduled 1RF21
2020-10-11 2020-11-05 26 504d 2020-10-20 -9d
Scheduled 1RF20
2019-04-22 2019-05-26 35 532d 2019-04-21 +1d
Scheduled 1RF19
2017-10-09 2017-11-06 29 496d 2017-10-31 -22d
Scheduled 1RF18
2016-05-02 2016-05-31 30 523d 2016-05-02 0d
Scheduled 1RF17
2014-10-05 2014-11-26 53 258d 2014-10-04 +1d
Scram # 49743
2014-01-19 2014-01-20 2 176d - -
Unscheduled
2013-07-27 2013-07-27 1 97d - -
Scheduled 1RF16
2013-03-31 2013-04-21 22 140d 2013-03-30 +1d
Scram # 48475
2012-11-02 2012-11-11 10 378d - -
Scheduled 1RF15
2011-10-02 2011-10-21 20 76d 2011-10-01 +1d
Unscheduled
2011-07-12 2011-07-18 7 179d - -
Unscheduled
2011-01-14 2011-01-14 1 263d - -
Scheduled 1RF14
2010-04-04 2010-04-26 23 73d 2010-04-03 +1d
Unscheduled
2010-01-19 2010-01-21 3 9d - -
Unscheduled
2010-01-10 2010-01-10 1 451d - -
Scheduled 1RF13
2008-09-28 2008-10-16 19 238d 2008-09-27 +1d
Unscheduled
2008-02-02 2008-02-03 2 288d - -
Scheduled 1RF12
2007-02-25 2007-04-20 55 475d 2007-02-24 +1d
Scheduled 1RF11
2005-10-09 2005-11-07 30 524d 2005-10-08 +1d
Scheduled 1RF10
2004-03-28 2004-05-03 37 316d 2004-03-27 +1d
Unscheduled
2003-05-15 2003-05-17 3 59d - -
Unscheduled
2003-03-17 2003-03-17 1 94d - -
Unscheduled
2002-12-04 2002-12-13 10 8d - -
Unscheduled
2002-11-24 2002-11-26 3 7d - -
Unscheduled
2002-11-12 2002-11-17 6 2d - -
Scheduled 1RF9
2002-09-28 2002-11-10 44 396d 2002-09-28 0d
Unscheduled
2001-08-19 2001-08-28 10 119d - -
Scheduled 1RF8
2001-03-25 2001-04-22 29 513d 2001-03-25 0d
Scheduled 1RF7
1999-09-25 1999-10-29 35 - 1999-09-25 0d
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