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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.
35
Excellence
#72 of 94 ↓12
Bottom Quartile
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Days of continuous operation since the last outage ended. Clean run (no forced outages since last refueling).
--
Current Run
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Longest recorded period of continuous operation between outages (2021-03-07 to 2022-10-10).
582
Record Run
days
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Breaker-to-Breaker runs — continuous operation exceeding the cycle-adjusted threshold (620 days for this 24-month cycle 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).
90.8%
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.
9.3
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.
99.8%
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
35/100
Bottom Quartile · #72/94
5-year window
Hatch 2 ranks #72 of 94 active US units on NukeWorker's Operational Excellence Score over the 5-year window. Strongest area: Capacity Factor (59th percentile). Weakest: Startup Duration (10th percentile).
Reliability
49
Capacity factor + Forced outages + B2B streaks
Efficiency
35
Fuel utilization + Refuel duration
Discipline
20
Startup duration + Scram count
Cohort Rankings
apples-to-apples comparison within each peer group
Reactor type:
#21 of 31
BWR
Containment:
#14 of 19
Mark I (BWR)
Cycle length:
#30 of 40
24-month cycle
Fleet rank above (72 of 94) compares all active US units; cohort ranks compare only against units sharing this property.
Per-dimension breakdown (7 metrics)
Capacity Factor
59th
92.3% (higher better, Reliability)
Forced Outage Days/yr
39th
5.0d (lower better, Reliability)
Fuel Utilization
23th
96.5% (higher better, Efficiency)
Refuel Duration
47th
33d (lower better, Efficiency)
Startup Duration
10th
8.1d (lower better, Discipline)
Scrams (5-year)
30th
0.6/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:
↓ -5.4 pts vs 2025
Compare Hatch 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 Mar 17, 2025
42.0% remaining
422 / 690 days
21.6 FPD margin
Avg refuel: 7.7%
Avg refuel (3yr): 0.2%
Deepest burn: 0.2% (2023-02 → 2025-02)
Most margin: 32.2% (2001-10 → 2003-03)
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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 |
|---|---|---|---|---|---|---|
|
Unscheduled
|
2026-05-11 | In Outage | 3+ | 236d | - | - |
|
Scram
# 57928
|
2025-09-14 | 2025-09-17 | 4 | 167d | - | - |
|
Unscheduled
|
2025-03-27 | 2025-03-31 | 5 | 13d | - | - |
|
Scheduled
|
2025-02-09 | 2025-03-14 | 34 | 462d | 2025-01-27 | +13d |
|
Scram
# 56826
|
2023-11-02 | 2023-11-05 | 4 | 214d | - | - |
|
Scram
# 56446
|
2023-04-01 | 2023-04-02 | 2 | 34d | - | - |
|
Scheduled
|
2023-01-29 | 2023-02-26 | 29 | 107d | 2023-02-05 | -7d |
|
Unscheduled
|
2022-10-10 | 2022-10-14 | 5 | 582d | - | - |
|
Scheduled
|
2021-02-08 | 2021-03-07 | 28 | 292d | 2021-02-07 | +1d |
|
Unscheduled
|
2020-04-15 | 2020-04-22 | 8 | 199d | - | - |
|
Unscheduled
|
2019-09-25 | 2019-09-29 | 5 | 182d | - | - |
|
Scram
# 53953
|
2019-03-24 | 2019-03-27 | 4 | 5d | - | - |
|
Scheduled
|
2019-02-04 | 2019-03-19 | 44 | 254d | 2019-02-04 | 0d |
|
Unscheduled
|
2018-05-19 | 2018-05-26 | 8 | 448d | - | - |
|
Scheduled
|
2017-02-06 | 2017-02-25 | 20 | 258d | 2017-02-05 | +1d |
|
Unscheduled
|
2016-05-21 | 2016-05-24 | 4 | 434d | - | - |
|
Unscheduled
|
2015-03-12 | 2015-03-14 | 3 | 2d | - | - |
|
Scheduled
|
2015-02-09 | 2015-03-10 | 30 | 507d | 2015-02-08 | +1d |
|
Unscheduled
|
2013-09-16 | 2013-09-20 | 5 | 183d | - | - |
|
Scheduled
|
2013-02-12 | 2013-03-17 | 34 | 279d | 2013-02-04 | +8d |
|
Unscheduled
|
2012-05-05 | 2012-05-09 | 5 | 138d | - | - |
|
Unscheduled
|
2011-12-15 | 2011-12-19 | 5 | 48d | - | - |
|
Scram
# 47369
|
2011-10-22 | 2011-10-28 | 7 | 144d | - | - |
|
Unscheduled
|
2011-05-28 | 2011-05-31 | 4 | 22d | - | - |
|
Unscheduled
|
2011-05-05 | 2011-05-06 | 2 | 4d | - | - |
|
Scheduled
|
2011-03-29 | 2011-05-01 | 34 | 348d | 2011-03-28 | +1d |
|
Unscheduled
|
2010-04-05 | 2010-04-15 | 11 | 286d | - | - |
|
Unscheduled
|
2009-06-23 | 2009-06-23 | 1 | 2d | - | - |
|
Unscheduled
|
2009-06-21 | 2009-06-21 | 1 | 30d | - | - |
|
Scheduled
SGR/Major
|
2009-02-09 | 2009-05-22 | 103 | 277d | 2009-02-09 | 0d |
|
Unscheduled
|
2008-05-08 | 2008-05-08 | 1 | 2d | - | - |
|
Unscheduled
|
2008-05-04 | 2008-05-06 | 3 | 56d | - | - |
|
Unscheduled
|
2008-03-08 | 2008-03-09 | 2 | 213d | - | - |
|
Unscheduled
|
2007-08-08 | 2007-08-08 | 1 | 146d | - | - |
|
Scheduled
|
2007-02-06 | 2007-03-15 | 38 | 306d | 2007-02-05 | +1d |
|
Unscheduled
|
2006-04-05 | 2006-04-06 | 2 | 313d | - | - |
|
Unscheduled
|
2005-05-24 | 2005-05-27 | 4 | 73d | - | - |
|
Scheduled
|
2005-02-05 | 2005-03-12 | 36 | 126d | 2005-02-04 | +1d |
|
Unscheduled
|
2004-09-25 | 2004-10-02 | 8 | 546d | - | - |
|
Scheduled
|
2003-03-01 | 2003-03-29 | 29 | 417d | 2003-03-01 | 0d |
|
Unscheduled
|
2001-12-26 | 2002-01-08 | 14 | 60d | - | - |
|
Unscheduled
|
2001-10-27 | 2001-10-27 | 1 | 5d | - | - |
|
Scheduled
|
2001-09-15 | 2001-10-22 | 38 | 525d | 2001-09-15 | 0d |
|
Scheduled
|
2000-03-04 | 2000-04-08 | 36 | 249d | 2000-03-04 | 0d |
|
Unscheduled
|
1999-06-28 | 1999-06-29 | 2 | 5d | - | - |
|
Unscheduled
|
1999-06-16 | 1999-06-23 | 8 | 38d | - | - |
|
Unscheduled
|
1999-05-06 | 1999-05-09 | 4 | 94d | - | - |
|
Unscheduled
|
1999-01-29 | 1999-02-01 | 4 | - | - | - |
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