LaSalle 1 - Status & History

Comprehensive reactor performance metrics, cycle analysis, and historical outage data.

Plant Info Outage History Daily Power Log
?
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.
72
Excellence
#15 of 94 ↑3
Top Quartile
?
Days of continuous operation since the last outage ended. Clean run (no forced outages since last refueling).
76
Current Run
days ✔
?
Longest recorded period of continuous operation between outages (2004-02-11 to 2006-02-20).
740
Record Run
days
?
Breaker-to-Breaker runs — continuous operation exceeding the cycle-adjusted threshold (632 days for this 24-month cycle unit) with no trips to 0% power.
4
B2B Runs
?
Lifetime capacity factor: average power level across all recorded days (100% = always at full power).
94.1%
Capacity Factor
?
Total number of scheduled refueling outages detected in the historical data.
13
Outages
since 1999
?
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.
3
Avg Startup
days (last 3)
?
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.
97.2%
Fuel Utilization
3yr avg
?
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.
Time window — change how far back we look
NukeWorker's
Operational
Excellence Score
72/100
Top Quartile · #15/94
5-year window

LaSalle 1 ranks #15 of 94 active US units on NukeWorker's Operational Excellence Score over the 5-year window. Strongest area: B2B Avg Streak (99th percentile). Weakest: Fuel Utilization (46th percentile).

Reliability
82
Capacity factor + Forced outages + B2B streaks
Efficiency
70
Fuel utilization + Refuel duration
Discipline
63
Startup duration + Scram count
Cohort Rankings apples-to-apples comparison within each peer group
Reactor type: #7 of 31 BWR
Containment: #4 of 8 Mark II (BWR)
Cycle length: #10 of 40 24-month cycle
Fleet rank above (15 of 94) compares all active US units; cohort ranks compare only against units sharing this property.
Per-dimension breakdown (7 metrics)
Capacity Factor 70th
93.4% (higher better, Reliability)
Forced Outage Days/yr 78th
1.6d (lower better, Reliability)
B2B Avg Streak 99th
714d (higher better, Reliability)
Fuel Utilization 46th
97.9% (higher better, Efficiency)
Refuel Duration 93th
18d (lower better, Efficiency)
Startup Duration 78th
3.4d (lower better, Discipline)
Scrams (5-year) 48th
0.4/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: 2021: 70/100 (#22/93)2022: 88/100 (#4/92)2023: 89/100 (#4/92)2024: 93/100 (#2/93)2025: 72/100 (#20/94)2026: 75/100 (#17/94) ↑ +2.4 pts vs 2025
Compare LaSalle 1 head-to-head with up to 3 other units. Compare now
?
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

?
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

?
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

?
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 Feb 28, 2026

89.7% remaining 74 / 702 days 1.3 FPD margin
Avg refuel: 2.0% Avg refuel (3yr): 2.8% Deepest burn: 0.0% (2004-02 → 2006-02) Most margin: 5.1% (2006-03 → 2008-02)
?
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
2026-02-09 2026-02-27 19 40d 2026-02-09 0d
Scram # 58100
2025-12-29 2025-12-31 3 55d - -
Unscheduled
2025-11-03 2025-11-04 2 605d - -
Scheduled
2024-02-19 2024-03-08 19 704d 2024-02-19 0d
Scheduled
2022-02-21 2022-03-17 25 725d 2022-02-21 0d
Scheduled
2020-02-10 2020-02-27 18 43d 2020-02-10 0d
Unscheduled
2019-12-27 2019-12-29 3 643d - -
Unscheduled
2018-03-23 2018-03-24 2 10d - -
Scheduled
2018-02-19 2018-03-13 23 238d 2018-02-19 0d
Unscheduled
2017-06-24 2017-06-26 3 125d - -
Scram # 52564
2017-02-18 2017-02-19 2 3d - -
Scram # 52564
2017-02-14 2017-02-15 2 330d - -
Unscheduled
2016-03-20 2016-03-21 2 5d - -
Unscheduled Startup Hold
2016-03-12 2016-03-15 4 4d - -
Scheduled
2016-02-15 2016-03-08 23 484d 2016-02-15 0d
Unscheduled
2014-10-12 2014-10-19 8 227d - -
Scheduled
2014-02-10 2014-02-27 18 287d 2014-02-10 0d
Scram # 48939
2013-04-18 2013-04-29 12 408d - -
Scram # 48939
2013-04-18 2013-04-29 12 11d - -
Scheduled
2012-02-13 2012-03-06 23 367d 2012-02-13 0d
Scram # 46582
2011-02-02 2011-02-11 10 333d - -
Scheduled
2010-02-08 2010-03-06 27 202d 2010-02-08 0d
Unscheduled
2009-07-19 2009-07-21 3 57d - -
Unscheduled
2009-05-22 2009-05-23 2 233d - -
Unscheduled
2008-09-30 2008-10-01 2 216d - -
Scheduled
2008-02-04 2008-02-27 24 689d 2008-02-04 0d
Scheduled
2006-02-20 2006-03-17 26 740d 2006-02-20 0d
Scheduled
2004-01-13 2004-02-11 30 46d 2004-01-13 0d
Unscheduled
2003-11-27 2003-11-28 2 551d - -
Unscheduled
2002-05-18 2002-05-25 8 104d - -
Scheduled
2002-01-11 2002-02-03 24 343d 2002-01-11 0d
Unscheduled
2001-02-01 2001-02-02 2 439d - -
Unscheduled
1999-10-23 1999-11-20 29 49d - -
Unscheduled
1999-09-03 1999-09-04 2 - - -
Page created in 0.097 seconds with 7 queries.