• 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.
Operational
Excellence Score
Oconee 2 ranks #24 of 94 active US units on NukeWorker's Operational Excellence Score over the 5-year window. Strongest area: Startup Duration (94th percentile). Weakest: Scrams (5-year) (30th percentile).
Per-dimension breakdown (7 metrics)
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.
Outage Duration Trend
Cycle Length History
Startup Duration Trend
Fuel Burn Down Cycle since Nov 26, 2025
Power History
| Type ⇅ | Actual Start ⇅ | Actual End ⇅ | Duration ⇅ | Days Online ⇅ | Scheduled | Delta |
|---|---|---|---|---|---|---|
|
Scheduled
|
2025-10-28 | 2025-11-25 | 29 | 707d | 2025-11-01 | -4d |
|
Scheduled
|
2023-10-28 | 2023-11-21 | 25 | 609d | 2023-10-28 | 0d |
|
Scram
# 55733
|
2022-02-05 | 2022-02-26 | 22 | 55d | - | - |
|
Scram
# 55638
|
2021-12-10 | 2021-12-12 | 3 | 3d | - | - |
|
Scheduled
|
2021-11-13 | 2021-12-07 | 25 | 703d | 2021-10-16 | +28d |
|
Scheduled
|
2019-11-09 | 2019-12-11 | 33 | 714d | 2019-10-28 | +12d |
|
Scheduled
|
2017-10-28 | 2017-11-25 | 29 | 717d | 2017-10-28 | 0d |
|
Scheduled
|
2015-10-17 | 2015-11-11 | 26 | 82d | 2015-10-17 | 0d |
|
Unscheduled
|
2015-07-27 | 2015-07-27 | 1 | 285d | - | - |
|
Unscheduled
|
2014-10-14 | 2014-10-15 | 2 | 314d | - | - |
|
Scheduled
|
2013-10-12 | 2013-12-04 | 54 | 695d | 2013-10-12 | 0d |
|
Scheduled
|
2011-10-22 | 2011-11-17 | 27 | 507d | 2011-10-22 | 0d |
|
Unscheduled
|
2010-05-31 | 2010-06-02 | 3 | 2d | - | - |
|
Scheduled
|
2010-04-25 | 2010-05-29 | 35 | 500d | 2010-04-24 | +1d |
|
Scheduled
|
2008-10-25 | 2008-12-11 | 48 | 207d | 2008-10-25 | 0d |
|
Unscheduled
|
2008-04-01 | 2008-04-01 | 1 | 307d | - | - |
|
Scheduled
|
2007-04-28 | 2007-05-30 | 33 | 70d | 2007-04-27 | +1d |
|
Unscheduled
|
2007-02-16 | 2007-02-17 | 2 | 305d | - | - |
|
Unscheduled
|
2006-04-13 | 2006-04-17 | 5 | 136d | - | - |
|
Scheduled
|
2005-10-22 | 2005-11-28 | 38 | 496d | 2005-10-21 | +1d |
|
Scheduled
SGR/Major
|
2004-03-20 | 2004-06-13 | 86 | 484d | 2004-03-19 | +1d |
|
Scheduled
|
2002-10-12 | 2002-11-22 | 42 | 501d | 2002-10-12 | 0d |
|
Scheduled
|
2001-04-26 | 2001-05-29 | 34 | 489d | 2001-04-26 | 0d |
|
Unscheduled
|
1999-12-24 | 1999-12-24 | 1 | 2d | - | - |
|
Unscheduled
|
1999-12-22 | 1999-12-22 | 1 | 7d | - | - |
|
Scheduled
|
1999-11-04 | 1999-12-15 | 42 | 135d | 1999-11-04 | 0d |
|
Unscheduled
|
1999-06-20 | 1999-06-22 | 3 | 110d | - | - |
|
Unscheduled
|
1999-03-01 | 1999-03-02 | 2 | 3d | - | - |
|
Unscheduled
|
1999-02-24 | 1999-02-26 | 3 | - | - | - |