• 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
Salem 2 ranks #45 of 94 active US units on NukeWorker's Operational Excellence Score over the 5-year window. Strongest area: Fuel Utilization (87th percentile). Weakest: Refuel Duration (16th 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
Power History
| Type ⇅ | Actual Start ⇅ | Actual End ⇅ | Duration ⇅ | Days Online ⇅ | Scheduled | Delta |
|---|---|---|---|---|---|---|
|
Scheduled
|
2026-04-05 | 2026-05-06 | 32 | 497d | 2026-04-04 | +1d |
|
Scheduled
|
2024-10-06 | 2024-11-24 | 50 | 528d | 2024-10-06 | 0d |
|
Unscheduled
Startup Hold
|
2023-04-26 | 2023-04-27 | 2 | 2d | - | - |
|
Scheduled
|
2023-04-01 | 2023-04-24 | 24 | 98d | 2023-04-09 | -8d |
|
Scram
# 56286
|
2022-12-24 | 2022-12-24 | 1 | 408d | - | - |
|
Scheduled
|
2021-10-02 | 2021-11-11 | 41 | 503d | 2021-10-02 | 0d |
|
Unscheduled
|
2020-05-15 | 2020-05-17 | 3 | 4d | - | - |
|
Scheduled
|
2020-04-11 | 2020-05-11 | 31 | 241d | 2020-04-03 | +8d |
|
Scram
# 54211
|
2019-08-12 | 2019-08-14 | 3 | 193d | - | - |
|
Scram
# 53852
|
2019-01-31 | 2019-01-31 | 1 | 80d | - | - |
|
Scheduled
|
2018-10-12 | 2018-11-12 | 32 | 26d | 2018-09-15 | +27d |
|
Scram
# 53606
|
2018-09-15 | 2018-09-16 | 2 | 130d | - | - |
|
Scram
# 53386
|
2018-05-07 | 2018-05-08 | 2 | 343d | - | - |
|
Scheduled
|
2017-04-15 | 2017-05-29 | 45 | 222d | 2017-04-13 | +2d |
|
Scram
# 52213
|
2016-09-01 | 2016-09-05 | 5 | 62d | - | - |
|
Scram
# 52048
|
2016-06-29 | 2016-07-01 | 3 | 134d | - | - |
|
Scram
# 51734
|
2016-02-15 | 2016-02-16 | 2 | 10d | - | - |
|
Scram
# 51708
|
2016-02-05 | 2016-02-05 | 1 | 70d | - | - |
|
Scheduled
|
2015-10-23 | 2015-11-27 | 36 | 76d | 2015-10-15 | +8d |
|
Scram
# 51290
|
2015-08-06 | 2015-08-08 | 3 | 389d | - | - |
|
Scheduled
SGR/Major
|
2014-04-13 | 2014-07-13 | 92 | 71d | 2014-04-14 | -1d |
|
Scram
# 49780
|
2014-02-01 | 2014-02-01 | 1 | 432d | - | - |
|
Scram
# 48534
|
2012-11-26 | 2012-11-26 | 1 | 9d | - | - |
|
Scheduled
|
2012-10-15 | 2012-11-17 | 34 | 202d | 2012-10-14 | +1d |
|
Scram
# 47766
|
2012-03-24 | 2012-03-27 | 4 | 250d | - | - |
|
Unscheduled
|
2011-07-15 | 2011-07-18 | 4 | 15d | - | - |
|
Scram
# 46992
|
2011-06-27 | 2011-06-30 | 4 | 51d | - | - |
|
Scheduled
|
2011-04-10 | 2011-05-07 | 28 | 174d | 2011-04-02 | +8d |
|
Unscheduled
|
2010-10-18 | 2010-10-18 | 1 | 269d | - | - |
|
Unscheduled
|
2010-01-22 | 2010-01-22 | 1 | 18d | - | - |
|
Unscheduled
|
2010-01-04 | 2010-01-04 | 1 | 55d | - | - |
|
Scheduled
|
2009-10-14 | 2009-11-10 | 28 | 517d | 2009-10-15 | -1d |
|
Unscheduled
|
2008-05-13 | 2008-05-15 | 3 | 7d | - | - |
|
Scheduled
|
2008-03-12 | 2008-05-06 | 56 | 287d | 2008-03-05 | +7d |
|
Unscheduled
|
2007-05-29 | 2007-05-30 | 2 | 3d | - | - |
|
Unscheduled
|
2007-05-24 | 2007-05-26 | 3 | 205d | - | - |
|
Scheduled
|
2006-10-11 | 2006-10-31 | 21 | 14d | 2006-10-10 | +1d |
|
Unscheduled
|
2006-09-27 | 2006-09-27 | 1 | 505d | - | - |
|
Scheduled
|
2005-04-06 | 2005-05-10 | 35 | 115d | 2005-04-05 | +1d |
|
Unscheduled
|
2004-12-04 | 2004-12-12 | 9 | 84d | - | - |
|
Unscheduled
|
2004-09-09 | 2004-09-11 | 3 | 51d | - | - |
|
Unscheduled
|
2004-07-14 | 2004-07-20 | 7 | 44d | - | - |
|
Unscheduled
|
2004-05-22 | 2004-05-31 | 10 | 179d | - | - |
|
Scheduled
|
2003-10-10 | 2003-11-25 | 47 | 15d | 2003-10-10 | 0d |
|
Unscheduled
|
2003-09-21 | 2003-09-25 | 5 | 174d | - | - |
|
Unscheduled
|
2003-03-30 | 2003-03-31 | 2 | 320d | - | - |
|
Scheduled
|
2002-04-05 | 2002-05-14 | 40 | 81d | 2002-04-05 | 0d |
|
Unscheduled
|
2002-01-12 | 2002-01-14 | 3 | 11d | - | - |
|
Unscheduled
|
2001-12-31 | 2002-01-01 | 2 | 412d | - | - |
|
Unscheduled
|
2000-11-14 | 2000-11-14 | 1 | 2d | - | - |
|
Scheduled
|
2000-10-06 | 2000-11-12 | 38 | 499d | 2000-10-06 | 0d |
|
Scheduled
|
1999-04-03 | 1999-05-26 | 54 | - | 1999-04-03 | 0d |