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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.
72
Excellence
#13 of 94 →
Top Quartile
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Days of continuous operation since the last outage ended. Clean run (no forced outages since last refueling).
31
Current Run
days ✔
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Longest recorded period of continuous operation between outages (2010-11-25 to 2012-11-12).
718
Record Run
days
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Breaker-to-Breaker runs — continuous operation exceeding the cycle-adjusted threshold (632 days for this 24-month cycle unit) with no trips to 0% power.
2
B2B Runs
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Lifetime capacity factor: average power level across all recorded days (100% = always at full power).
93.4%
Capacity Factor
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Total number of scheduled refueling outages detected in the historical data.
14
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.
94.7%
Fuel Utilization
lifetime avg
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NukeWorker's Operational Excellence Score is a composite 0–100 ranking of every active US nuclear unit across 7 publicly observable 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
NukeWorker's
Operational
Excellence Score
Operational
Excellence Score
72/100
Top Quartile · #13/94
5-year window
Dresden 3 ranks #13 of 94 active US units on NukeWorker's Operational Excellence Score over the 5-year window. Strongest area: B2B Avg Streak (100th percentile). Weakest: Forced Outage Days/yr (25th percentile).
Reliability
70
Capacity factor + Forced outages + B2B streaks
Efficiency
65
Fuel utilization + Refuel duration
Discipline
81
Startup duration + Scram count
Cohort Rankings
apples-to-apples comparison within each peer group
Reactor type:
#6 of 31
BWR
Containment:
#3 of 19
Mark I (BWR)
Cycle length:
#9 of 40
24-month cycle
Fleet rank above (13 of 94) compares all active US units; cohort ranks compare only against units sharing this property.
Per-dimension breakdown (7 metrics)
Capacity Factor
86th
94.9% (higher better, Reliability)
Forced Outage Days/yr
25th
7.0d (lower better, Reliability)
B2B Avg Streak
100th
715d (higher better, Reliability)
Fuel Utilization
36th
97.4% (higher better, Efficiency)
Refuel Duration
93th
18d (lower better, Efficiency)
Startup Duration
92th
3.0d (lower better, Discipline)
Scrams (5-year)
70th
0.2/yr (lower better, Discipline)
Each dimension's percentile is computed across the active US fleet (94 units with sufficient history). Sub-score = average of its component percentiles. Composite = average of the three sub-scores. 5-year window. View full leaderboard →
Methodology
NukeWorker's Operational Excellence Score is a composite ranking that combines 7 publicly observable performance metrics into a single 0-100 number per US nuclear unit.
How it's computed: Each unit's raw value is converted to a percentile (0-100) within the 94 active US units that have at least 2 completed refueling cycles. The 7 percentiles are averaged into 3 sub-scores (Reliability, Efficiency, Discipline), and those are averaged into the final composite.
Active window — 5-year:
- Reliability — Capacity factor (5yr), forced outage days/yr (5yr), B2B avg streak (lifetime)
- Efficiency — in-cycle fuel utilization (3yr), median refuel duration (5yr)
- Discipline — robust mean startup duration, scrams/yr (5yr, annualised)
Cohort rankings: alongside the fleet rank, each unit gets ranked within its reactor type (PWR/BWR), containment design (Ice Condenser, Mark I, etc.), and cycle length (12/18/24-month). Useful for apples-to-apples comparisons.
What's excluded: subjective community ratings, confidential INPO ratings, financial metrics. We only use publicly available NRC + cycle data.
Why three windows? 5yr (default) is the industry standard. 3yr captures recent operational changes and post-pandemic recovery. Lifetime gives newer units a fair comparison and reveals long-term consistency.
Edge cases: units with fewer than 2 cycles (e.g., Vogtle 4) show "Provisional". Decommissioned units excluded.
Refresh cadence: recomputed daily. Each window cached separately.
A data-derived proxy for operational performance; not affiliated with INPO. INPO ratings are confidential and qualitative — ours is public and quantitative.
5-yr trend:
Stable vs 2025
Compare Dresden 3 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
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Days between consecutive scheduled refueling outage starts, showing operating cycle regularity. The purple dashed line marks the average cycle length. Most U.S. reactors operate on 18-month (547 day) or 24-month (730 day) cycles.
Cycle Length History
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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
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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 Nov 16, 2024
25.9% remaining
543 / 711 days
16.1 FPD margin
Avg refuel: 5.3%
Deepest burn: 0.8% (2010-11 → 2012-11)
Most margin: 23.9% (1999-02 → 2000-09)
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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
| Type ⇅ | Actual Start ⇅ | Actual End ⇅ | Duration ⇅ | Days Online ⇅ | Scheduled | Delta |
|---|---|---|---|---|---|---|
|
Unscheduled
|
2026-04-08 | 2026-04-13 | 6 | 212d | - | - |
|
Unscheduled
|
2025-09-04 | 2025-09-08 | 5 | 293d | - | - |
|
Scheduled
|
2024-10-28 | 2024-11-15 | 19 | 62d | 2024-10-28 | 0d |
|
Unscheduled
|
2024-08-24 | 2024-08-27 | 4 | 489d | - | - |
|
Unscheduled
|
2023-04-22 | 2023-04-23 | 2 | 156d | - | - |
|
Scheduled
|
2022-10-31 | 2022-11-17 | 18 | 202d | 2022-10-31 | 0d |
|
Unscheduled
|
2022-04-11 | 2022-04-12 | 2 | 163d | - | - |
|
Scram
# 55527
|
2021-10-17 | 2021-10-30 | 14 | 345d | - | - |
|
Scheduled
|
2020-10-26 | 2020-11-06 | 12 | 72d | 2020-10-26 | 0d |
|
Unscheduled
|
2020-08-12 | 2020-08-15 | 4 | 639d | - | - |
|
Scheduled
|
2018-10-30 | 2018-11-12 | 14 | 713d | 2018-10-29 | +1d |
|
Scheduled
|
2016-11-01 | 2016-11-16 | 16 | 331d | 2016-10-31 | +1d |
|
Unscheduled
|
2015-11-30 | 2015-12-06 | 7 | 377d | - | - |
|
Scheduled
|
2014-11-03 | 2014-11-18 | 16 | 375d | 2014-11-03 | 0d |
|
Unscheduled
|
2013-10-20 | 2013-10-24 | 5 | 321d | - | - |
|
Scheduled
|
2012-11-12 | 2012-12-03 | 22 | 718d | 2012-11-12 | 0d |
|
Scheduled
|
2010-11-01 | 2010-11-25 | 25 | 19d | 2010-11-01 | 0d |
|
Unscheduled
|
2010-10-12 | 2010-10-13 | 2 | 371d | - | - |
|
Unscheduled
|
2009-10-04 | 2009-10-06 | 3 | 162d | - | - |
|
Unscheduled
|
2009-04-25 | 2009-04-25 | 1 | 157d | - | - |
|
Scheduled
|
2008-11-03 | 2008-11-19 | 17 | 291d | 2008-11-03 | 0d |
|
Unscheduled
|
2008-01-10 | 2008-01-17 | 8 | 117d | - | - |
|
Unscheduled
|
2007-09-15 | 2007-09-15 | 1 | 297d | - | - |
|
Scheduled
|
2006-11-04 | 2006-11-22 | 19 | 346d | 2006-11-03 | +1d |
|
Unscheduled
|
2005-11-06 | 2005-11-23 | 18 | 191d | - | - |
|
Unscheduled
|
2005-04-27 | 2005-04-29 | 3 | 143d | - | - |
|
Scheduled
|
2004-10-27 | 2004-12-05 | 40 | 171d | 2004-10-26 | +1d |
|
Unscheduled
|
2004-05-06 | 2004-05-09 | 4 | 95d | - | - |
|
Unscheduled
|
2004-01-31 | 2004-02-01 | 2 | 7d | - | - |
|
Unscheduled
|
2004-01-24 | 2004-01-24 | 1 | 35d | - | - |
|
Unscheduled
|
2003-12-06 | 2003-12-20 | 15 | 172d | - | - |
|
Unscheduled
|
2003-06-12 | 2003-06-17 | 6 | 183d | - | - |
|
Unscheduled
|
2002-12-08 | 2002-12-11 | 4 | 44d | - | - |
|
Scheduled
|
2002-10-09 | 2002-10-25 | 17 | 77d | 2002-10-09 | 0d |
|
Unscheduled
|
2002-07-22 | 2002-07-24 | 3 | 121d | - | - |
|
Unscheduled
|
2002-03-16 | 2002-03-23 | 8 | 88d | - | - |
|
Unscheduled
|
2001-12-11 | 2001-12-18 | 8 | 8d | - | - |
|
Unscheduled
|
2001-12-02 | 2001-12-03 | 2 | 149d | - | - |
|
Unscheduled
|
2001-07-06 | 2001-07-06 | 1 | 3d | - | - |
|
Unscheduled
|
2001-07-02 | 2001-07-03 | 2 | 64d | - | - |
|
Unscheduled
|
2001-04-28 | 2001-04-29 | 2 | 208d | - | - |
|
Scheduled
|
2000-09-16 | 2000-10-02 | 17 | 134d | 2000-09-16 | 0d |
|
Unscheduled
|
2000-05-04 | 2000-05-05 | 2 | 144d | - | - |
|
Unscheduled
|
1999-12-11 | 1999-12-12 | 2 | 263d | - | - |
|
Unscheduled
|
1999-03-22 | 1999-03-23 | 2 | 26d | - | - |
|
Scheduled
|
1999-01-30 | 1999-02-24 | 26 | - | 1999-01-30 | 0d |
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