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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.
61
Excellence
#32 of 94 ↑12
Mid Quartile
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Days of continuous operation since the last outage ended. Clean run (no forced outages since last refueling).
349
Current Run
days ✔
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Longest recorded period of continuous operation between outages (2017-11-11 to 2019-04-13).
518
Record Run
days
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Breaker-to-Breaker runs — continuous operation exceeding the cycle-adjusted threshold (444 days for this 18-month cycle unit) with no trips to 0% power.
4
B2B Runs
77% toward B2B (341/444d)
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Lifetime capacity factor: average power level across all recorded days (100% = always at full power).
88.7%
Capacity Factor
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Total number of scheduled refueling outages detected in the historical data.
18
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.
2.3
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.
100.0%
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.
• 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
61/100
Mid Quartile · #32/94
5-year window
Salem 1 ranks #32 of 94 active US units on NukeWorker's Operational Excellence Score over the 5-year window. Strongest area: Scrams (5-year) (90th percentile). Weakest: Refuel Duration (20th percentile).
Reliability
60
Capacity factor + Forced outages + B2B streaks
Efficiency
48
Fuel utilization + Refuel duration
Discipline
75
Startup duration + Scram count
Cohort Rankings
apples-to-apples comparison within each peer group
Reactor type:
#20 of 61
PWR
Containment:
#17 of 48
Dry Ambient (PWR)
Cycle length:
#15 of 54
18-month cycle
Fleet rank above (32 of 94) compares all active US units; cohort ranks compare only against units sharing this property.
Per-dimension breakdown (7 metrics)
Capacity Factor
72th
93.7% (higher better, Reliability)
Forced Outage Days/yr
87th
1.0d (lower better, Reliability)
B2B Avg Streak
22th
502d (higher better, Reliability)
Fuel Utilization
75th
98.6% (higher better, Efficiency)
Refuel Duration
20th
39d (lower better, Efficiency)
Startup Duration
60th
4.0d (lower better, Discipline)
Scrams (5-year)
90th
0.0/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:
↑ +6.0 pts vs 2025
Compare Salem 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 May 31, 2025
31.5% remaining
347 / 506 days
0.5 FPD margin
Avg refuel: 4.3%
Avg refuel (3yr): 0.0%
Deepest burn: 0.0% (2007-04 → 2008-10)
Most margin: 15.4% (2016-07 → 2017-10)
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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
| Type ⇅ | Actual Start ⇅ | Actual End ⇅ | Duration ⇅ | Days Online ⇅ | Scheduled | Delta |
|---|---|---|---|---|---|---|
|
Scheduled
|
2025-04-13 | 2025-05-30 | 48 | 85d | 2025-04-02 | +11d |
|
Unscheduled
|
2025-01-17 | 2025-01-18 | 2 | 433d | - | - |
|
Scheduled
|
2023-10-08 | 2023-11-11 | 35 | 508d | 2023-10-07 | +1d |
|
Scheduled
|
2022-04-09 | 2022-05-18 | 40 | 478d | 2022-04-09 | 0d |
|
Unscheduled
|
2020-12-16 | 2020-12-17 | 2 | 3d | - | - |
|
Scheduled
|
2020-10-03 | 2020-12-13 | 72 | 192d | 2020-10-20 | -17d |
|
Unscheduled
|
2020-02-26 | 2020-03-25 | 29 | 253d | - | - |
|
Scheduled
|
2019-04-13 | 2019-06-18 | 67 | 518d | 2019-04-16 | -3d |
|
Scheduled
|
2017-10-13 | 2017-11-11 | 30 | 225d | 2017-10-13 | 0d |
|
Unscheduled
|
2017-03-01 | 2017-03-02 | 2 | 215d | - | - |
|
Scheduled
SGR/Major
|
2016-04-15 | 2016-07-29 | 106 | 391d | 2016-04-14 | +1d |
|
Unscheduled
|
2015-03-16 | 2015-03-21 | 6 | 115d | - | - |
|
Scheduled
|
2014-10-20 | 2014-11-21 | 33 | 163d | 2014-10-19 | +1d |
|
Scram
# 50092
|
2014-05-08 | 2014-05-10 | 3 | 21d | - | - |
|
Scram
# 50032
|
2014-04-14 | 2014-04-17 | 4 | 5d | - | - |
|
Scram
# 50012
|
2014-04-09 | 2014-04-09 | 1 | 228d | - | - |
|
Unscheduled
|
2013-08-23 | 2013-08-24 | 2 | 93d | - | - |
|
Scheduled
|
2013-04-15 | 2013-05-22 | 38 | 165d | 2013-04-14 | +1d |
|
Scram
# 48457
|
2012-10-30 | 2012-11-01 | 3 | 177d | - | - |
|
Scram
# 47874
|
2012-05-01 | 2012-05-06 | 6 | 165d | - | - |
|
Scheduled
|
2011-10-24 | 2011-11-18 | 26 | 185d | 2011-10-22 | +2d |
|
Scram
# 46774
|
2011-04-22 | 2011-04-22 | 1 | 188d | - | - |
|
Unscheduled
|
2010-10-16 | 2010-10-16 | 1 | 85d | - | - |
|
Unscheduled
|
2010-07-08 | 2010-07-23 | 16 | 72d | - | - |
|
Scheduled
|
2010-04-04 | 2010-04-27 | 24 | 508d | 2010-04-07 | -3d |
|
Scheduled
|
2008-10-15 | 2008-11-12 | 29 | 288d | 2008-10-15 | 0d |
|
Unscheduled
|
2007-12-29 | 2008-01-01 | 4 | 241d | - | - |
|
Unscheduled
|
2007-05-01 | 2007-05-02 | 2 | 6d | - | - |
|
Unscheduled
Startup Hold
|
2007-04-25 | 2007-04-25 | 1 | 8d | - | - |
|
Scheduled
|
2007-03-28 | 2007-04-17 | 21 | 384d | 2007-03-27 | +1d |
|
Unscheduled
|
2006-03-09 | 2006-03-09 | 1 | 125d | - | - |
|
Scheduled
|
2005-10-12 | 2005-11-04 | 24 | 174d | 2005-10-11 | +1d |
|
Unscheduled
|
2005-04-20 | 2005-04-21 | 2 | 125d | - | - |
|
Unscheduled
|
2004-12-04 | 2004-12-16 | 13 | 68d | - | - |
|
Unscheduled
|
2004-09-25 | 2004-09-27 | 3 | 114d | - | - |
|
Unscheduled
|
2004-06-03 | 2004-06-03 | 1 | 5d | - | - |
|
Scheduled
|
2004-03-31 | 2004-05-29 | 60 | 165d | 2004-03-30 | +1d |
|
Unscheduled
|
2003-10-16 | 2003-10-18 | 3 | 21d | - | - |
|
Unscheduled
|
2003-09-20 | 2003-09-25 | 6 | 50d | - | - |
|
Unscheduled
|
2003-07-30 | 2003-08-01 | 3 | 266d | - | - |
|
Scheduled
|
2002-10-11 | 2002-11-06 | 27 | 213d | 2002-10-11 | 0d |
|
Unscheduled
|
2002-03-06 | 2002-03-12 | 7 | 142d | - | - |
|
Unscheduled
|
2001-09-25 | 2001-10-15 | 21 | 124d | - | - |
|
Unscheduled
|
2001-05-23 | 2001-05-24 | 2 | 6d | - | - |
|
Scheduled
|
2001-04-06 | 2001-05-17 | 42 | 118d | 2001-04-06 | 0d |
|
Unscheduled
|
2000-12-09 | 2000-12-09 | 1 | 120d | - | - |
|
Unscheduled
|
2000-08-10 | 2000-08-11 | 2 | 117d | - | - |
|
Unscheduled
|
2000-04-13 | 2000-04-15 | 3 | 91d | - | - |
|
Unscheduled
|
2000-01-07 | 2000-01-13 | 7 | 74d | - | - |
|
Scheduled
|
1999-09-18 | 1999-10-25 | 38 | 118d | 1999-09-18 | 0d |
|
Unscheduled
|
1999-05-21 | 1999-05-23 | 3 | 79d | - | - |
|
Unscheduled
|
1999-02-28 | 1999-03-03 | 4 | - | - | - |
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