Dresden 2 - Status & History

Comprehensive reactor performance metrics, cycle analysis, and historical outage data.

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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
#16 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).
178
Current Run
days ✔
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Longest recorded period of continuous operation between outages (2023-11-15 to 2025-10-27).
712
Record Run
days
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Breaker-to-Breaker runs — continuous operation exceeding the cycle-adjusted threshold (629 days for this 24-month cycle unit) with no trips to 0% power.
3
B2B Runs
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Lifetime capacity factor: average power level across all recorded days (100% = always at full power).
92.9%
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.
3.3
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.
99.0%
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 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.
Time window — change how far back we look
NukeWorker's
Operational
Excellence Score
72/100
Top Quartile · #16/94
5-year window

Dresden 2 ranks #16 of 94 active US units on NukeWorker's Operational Excellence Score over the 5-year window. Strongest area: Capacity Factor (93th percentile). Weakest: Startup Duration (37th percentile).

Reliability
84
Capacity factor + Forced outages + B2B streaks
Efficiency
78
Fuel utilization + Refuel duration
Discipline
53
Startup duration + Scram count
Cohort Rankings apples-to-apples comparison within each peer group
Reactor type: #8 of 31 BWR
Containment: #4 of 19 Mark I (BWR)
Cycle length: #11 of 40 24-month cycle
Fleet rank above (16 of 94) compares all active US units; cohort ranks compare only against units sharing this property.
Per-dimension breakdown (7 metrics)
Capacity Factor 93th
95.8% (higher better, Reliability)
Forced Outage Days/yr 72th
2.0d (lower better, Reliability)
B2B Avg Streak 87th
702d (higher better, Reliability)
Fuel Utilization 70th
98.4% (higher better, Efficiency)
Refuel Duration 85th
21d (lower better, Efficiency)
Startup Duration 37th
5.1d (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: 2021: 79/100 (#11/93)2022: 73/100 (#17/92)2023: 71/100 (#17/92)2024: 81/100 (#12/93)2025: 78/100 (#12/94)2026: 79/100 (#11/94) Stable vs 2025
Compare Dresden 2 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 19, 2025

75.5% remaining 175 / 708 days 1.3 FPD margin
Avg refuel: 4.2% Avg refuel (3yr): 1.0% Deepest burn: 0.0% (2011-11 → 2013-11) Most margin: 16.5% (2003-11 → 2005-10)
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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

Scheduled
2025-10-27 2025-11-17 22 712d 2025-10-27 0d
Scheduled
2023-10-30 2023-11-15 17 186d 2023-10-30 0d
Unscheduled
2023-04-26 2023-04-27 2 287d - -
Scram # 55988
2022-07-13 2022-07-13 1 234d - -
Scheduled
2021-11-08 2021-11-21 14 176d 2021-11-01 +7d
Unscheduled
2021-05-12 2021-05-16 5 495d - -
Unscheduled
2019-12-28 2020-01-03 7 44d - -
Scheduled
2019-10-28 2019-11-14 18 170d 2019-10-30 -2d
Scram # 54054
2019-05-10 2019-05-11 2 540d - -
Scheduled
2017-10-30 2017-11-16 18 711d 2017-10-30 0d
Scheduled
2015-11-02 2015-11-19 18 264d 2015-11-02 0d
Scram # 50792
2015-02-07 2015-02-11 5 23d - -
Scram # 50733
2015-01-14 2015-01-15 2 255d - -
Scram # 50085
2014-05-04 2014-05-04 1 9d - -
Scram # 50030
2014-04-13 2014-04-25 13 136d - -
Scheduled
2013-11-11 2013-11-28 18 433d 2013-11-11 0d
Unscheduled
2012-08-31 2012-09-04 5 296d - -
Scheduled
2011-10-17 2011-11-09 24 685d 2011-10-17 0d
Scheduled
2009-11-02 2009-12-01 30 399d 2009-11-02 0d
Unscheduled
2008-09-25 2008-09-29 5 312d - -
Scheduled
2007-10-29 2007-11-18 21 175d 2007-10-27 +2d
Unscheduled
2007-05-05 2007-05-07 3 161d - -
Unscheduled
2006-11-17 2006-11-25 9 135d - -
Unscheduled
2006-07-04 2006-07-05 2 227d - -
Scheduled
2005-10-31 2005-11-19 20 48d 2005-10-30 +1d
Unscheduled
2005-08-31 2005-09-13 14 157d - -
Unscheduled
2005-03-25 2005-03-27 3 104d - -
Unscheduled
2004-11-03 2004-12-11 39 41d - -
Unscheduled
2004-09-19 2004-09-23 5 31d - -
Unscheduled
2004-08-15 2004-08-19 5 98d - -
Unscheduled
2004-04-29 2004-05-09 11 2d - -
Unscheduled
2004-04-25 2004-04-27 3 135d - -
Unscheduled
2003-12-12 2003-12-12 1 33d - -
Scheduled
2003-10-15 2003-11-09 26 14d 2003-10-15 0d
Unscheduled
2003-10-01 2003-10-01 1 692d - -
Scheduled
2001-10-21 2001-11-08 19 43d 2001-10-21 0d
Unscheduled
2001-09-02 2001-09-08 7 149d - -
Unscheduled
2001-04-04 2001-04-06 3 124d - -
Unscheduled
2000-12-01 2000-12-01 1 402d - -
Scheduled
1999-10-02 1999-10-26 25 - 1999-10-02 0d
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