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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.
50
Excellence
#47 of 94 →
Mid Quartile
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Days of continuous operation since the last outage ended. Clean run (no forced outages since last refueling).
30
Current Run
days ✔
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Longest recorded period of continuous operation between outages (2000-03-23 to 2002-03-02).
709
Record Run
days
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Breaker-to-Breaker runs — continuous operation exceeding the cycle-adjusted threshold (606 days for this 24-month cycle unit) with no trips to 0% power.
1
B2B Runs
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Lifetime capacity factor: average power level across all recorded days (100% = always at full power).
90.3%
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.
9
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.
98.3%
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.
• 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
50/100
Mid Quartile · #47/94
5-year window
Brunswick 1 ranks #47 of 94 active US units on NukeWorker's Operational Excellence Score over the 5-year window. Strongest area: B2B Avg Streak (94th percentile). Weakest: Startup Duration (13th percentile).
Reliability
58
Capacity factor + Forced outages + B2B streaks
Efficiency
51
Fuel utilization + Refuel duration
Discipline
42
Startup duration + Scram count
Cohort Rankings
apples-to-apples comparison within each peer group
Reactor type:
#15 of 31
BWR
Containment:
#10 of 19
Mark I (BWR)
Cycle length:
#21 of 40
24-month cycle
Fleet rank above (47 of 94) compares all active US units; cohort ranks compare only against units sharing this property.
Per-dimension breakdown (7 metrics)
Capacity Factor
27th
88.3% (higher better, Reliability)
Forced Outage Days/yr
52th
3.4d (lower better, Reliability)
B2B Avg Streak
94th
708d (higher better, Reliability)
Fuel Utilization
38th
97.5% (higher better, Efficiency)
Refuel Duration
63th
29d (lower better, Efficiency)
Startup Duration
13th
7.7d (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 Brunswick 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
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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 Apr 17, 2026
96.5% remaining
26 / 707 days
1.2 FPD margin
Avg refuel: 6.6%
Avg refuel (3yr): 1.7%
Deepest burn: 1.2% (2000-03 → 2002-03)
Most margin: 10.5% (2012-05 → 2014-03)
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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
| Type ⇅ | Actual Start ⇅ | Actual End ⇅ | Duration ⇅ | Days Online ⇅ | Scheduled | Delta |
|---|---|---|---|---|---|---|
|
Scheduled
|
2026-02-26 | 2026-04-14 | 48 | 486d | 2026-02-28 | -2d |
|
Unscheduled
|
2024-10-27 | 2024-10-28 | 2 | 2d | - | - |
|
Unscheduled
|
2024-10-17 | 2024-10-25 | 9 | 219d | - | - |
|
Scheduled
|
2024-02-12 | 2024-03-12 | 30 | 296d | 2024-03-01 | -18d |
|
Scram
# 56478
|
2023-04-20 | 2023-04-22 | 3 | 383d | - | - |
|
Scheduled
|
2022-03-05 | 2022-04-02 | 29 | 297d | 2022-03-05 | 0d |
|
Unscheduled
|
2021-05-02 | 2021-05-12 | 11 | 255d | - | - |
|
Scram
# 54812
|
2020-08-04 | 2020-08-20 | 17 | 44d | - | - |
|
Unscheduled
|
2020-06-13 | 2020-06-21 | 9 | 78d | - | - |
|
Unscheduled
Startup Hold
|
2020-03-25 | 2020-03-27 | 3 | 2d | - | - |
|
Scheduled
|
2020-02-29 | 2020-03-23 | 24 | 174d | 2020-02-29 | 0d |
|
Unscheduled
|
2019-09-06 | 2019-09-08 | 3 | 133d | - | - |
|
Scram
# 54016
|
2019-04-22 | 2019-04-26 | 5 | 12d | - | - |
|
Scram
# 53961
|
2019-03-29 | 2019-04-10 | 13 | 189d | - | - |
|
Unscheduled
|
2018-09-14 | 2018-09-21 | 8 | 158d | - | - |
|
Scram
# 53319
|
2018-04-08 | 2018-04-09 | 2 | 5d | - | - |
|
Scheduled
|
2018-03-03 | 2018-04-03 | 32 | 309d | 2018-03-03 | 0d |
|
Unscheduled
|
2017-04-26 | 2017-04-28 | 3 | 399d | - | - |
|
Scheduled
|
2016-02-27 | 2016-03-23 | 26 | 14d | 2016-02-27 | 0d |
|
Scram
# 51715
|
2016-02-08 | 2016-02-13 | 6 | 90d | - | - |
|
Unscheduled
|
2015-11-08 | 2015-11-10 | 3 | 578d | - | - |
|
Scheduled
|
2014-03-01 | 2014-04-09 | 40 | 277d | 2014-03-01 | 0d |
|
Unscheduled
|
2013-05-18 | 2013-05-28 | 11 | 234d | - | - |
|
Unscheduled
|
2012-09-17 | 2012-09-26 | 10 | 141d | - | - |
|
Scheduled
SGR/Major
|
2012-02-24 | 2012-04-29 | 66 | 283d | 2012-03-03 | -8d |
|
Unscheduled
|
2011-05-14 | 2011-05-17 | 4 | 372d | - | - |
|
Unscheduled
|
2010-05-06 | 2010-05-07 | 2 | 12d | - | - |
|
Scheduled
|
2010-02-27 | 2010-04-24 | 57 | 150d | 2010-02-27 | 0d |
|
Unscheduled
|
2009-09-21 | 2009-09-30 | 10 | 297d | - | - |
|
Unscheduled
|
2008-11-27 | 2008-11-28 | 2 | 3d | - | - |
|
Unscheduled
|
2008-11-20 | 2008-11-24 | 5 | 207d | - | - |
|
Scheduled
|
2008-03-15 | 2008-04-27 | 44 | 177d | 2008-03-15 | 0d |
|
Unscheduled
|
2007-09-08 | 2007-09-20 | 13 | 156d | - | - |
|
Unscheduled
|
2007-04-02 | 2007-04-05 | 4 | 223d | - | - |
|
Unscheduled
|
2006-08-11 | 2006-08-22 | 12 | 127d | - | - |
|
Scheduled
|
2006-03-04 | 2006-04-06 | 34 | 206d | 2006-03-03 | +1d |
|
Unscheduled
|
2005-08-07 | 2005-08-10 | 4 | 19d | - | - |
|
Unscheduled
|
2005-07-14 | 2005-07-19 | 6 | 82d | - | - |
|
Unscheduled
|
2005-04-16 | 2005-04-23 | 8 | 242d | - | - |
|
Unscheduled
|
2004-08-15 | 2004-08-17 | 3 | 137d | - | - |
|
Scheduled
|
2004-02-28 | 2004-03-31 | 33 | 241d | 2004-02-27 | +1d |
|
Unscheduled
|
2003-07-01 | 2003-07-02 | 2 | 169d | - | - |
|
Unscheduled
|
2003-01-13 | 2003-01-13 | 1 | 107d | - | - |
|
Unscheduled
|
2002-09-22 | 2002-09-28 | 7 | 178d | - | - |
|
Scheduled
|
2002-03-02 | 2002-03-28 | 27 | 709d | 2002-03-02 | 0d |
|
Scheduled
|
2000-02-26 | 2000-03-23 | 27 | 112d | 2000-02-26 | 0d |
|
Unscheduled
|
1999-11-06 | 1999-11-06 | 1 | 48d | - | - |
|
Unscheduled
|
1999-09-16 | 1999-09-19 | 4 | 15d | - | - |
|
Unscheduled
|
1999-08-30 | 1999-09-01 | 3 | 218d | - | - |
|
Unscheduled
|
1999-01-24 | 1999-01-24 | 1 | - | - | - |
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