McGuire 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.
71
Excellence
#17 of 94 →
Top Quartile
?
Days of continuous operation since the last outage ended. Clean run (no forced outages since last refueling).
132
Current Run
days ✔
?
Longest recorded period of continuous operation between outages (2020-10-20 to 2022-04-02).
529
Record Run
days
?
Breaker-to-Breaker runs — continuous operation exceeding the cycle-adjusted threshold (455 days for this 18-month cycle unit) with no trips to 0% power.
7
B2B Runs
?
Lifetime capacity factor: average power level across all recorded days (100% = always at full power).
91.8%
Capacity Factor
?
Total number of scheduled refueling outages detected in the historical data.
18
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.
2.3
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.
99.5%
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
71/100
Top Quartile · #17/94
5-year window

McGuire 1 ranks #17 of 94 active US units on NukeWorker's Operational Excellence Score over the 5-year window. Strongest area: Fuel Utilization (96th percentile). Weakest: Refuel Duration (29th percentile).

Reliability
69
Capacity factor + Forced outages + B2B streaks
Efficiency
63
Fuel utilization + Refuel duration
Discipline
82
Startup duration + Scram count
Cohort Rankings apples-to-apples comparison within each peer group
Reactor type: #9 of 61 PWR
Containment: #2 of 10 Ice Condenser
Cycle length: #6 of 54 18-month cycle
Fleet rank above (17 of 94) compares all active US units; cohort ranks compare only against units sharing this property.
Per-dimension breakdown (7 metrics)
Capacity Factor 82th
94.6% (higher better, Reliability)
Forced Outage Days/yr 83th
1.4d (lower better, Reliability)
B2B Avg Streak 43th
511d (higher better, Reliability)
Fuel Utilization 96th
99.2% (higher better, Efficiency)
Refuel Duration 29th
36d (lower better, Efficiency)
Startup Duration 94th
2.9d (lower better, Discipline)
Scrams (5-year) 70th
0.2/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: 63/100 (#29/93)2022: 55/100 (#40/92)2023: 55/100 (#38/92)2024: 60/100 (#25/93)2025: 55/100 (#31/94)2026: 56/100 (#32/94) Stable vs 2025
Compare McGuire 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 Apr 21, 2025

27.9% remaining 387 / 524 days 9.2 FPD margin
Avg refuel: 4.4% Avg refuel (3yr): 0.5% Deepest burn: 0.0% (2020-10 → 2022-04) Most margin: 10.0% (2007-05 → 2008-09)
?
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
Scram # 58101
2025-12-30 2026-01-02 4 254d - -
Scheduled
2025-04-02 2025-04-20 19 526d 2025-03-29 +4d
Scheduled
2023-09-16 2023-10-24 39 496d 2023-09-16 0d
Scheduled
2022-04-02 2022-05-08 37 529d 2022-03-26 +7d
Scheduled
2020-09-19 2020-10-20 32 504d 2020-09-26 -7d
Scram # 54047
2019-05-04 2019-05-04 1 18d - -
Scheduled
2019-03-23 2019-04-16 25 399d 2019-03-23 0d
Scram # 53217
2018-02-17 2018-02-17 1 124d - -
Scheduled
2017-09-23 2017-10-16 24 525d 2017-09-23 0d
Scheduled
2016-03-19 2016-04-16 29 400d 2016-03-19 0d
Unscheduled
2015-02-07 2015-02-13 7 85d - -
Scheduled
2014-09-13 2014-11-14 63 302d 2014-09-13 0d
Scram # 49538
2013-11-15 2013-11-15 1 207d - -
Scheduled
2013-03-17 2013-04-22 37 22d 2013-03-16 +1d
Scram # 48775
2013-02-22 2013-02-23 2 497d - -
Scheduled
2011-09-18 2011-10-14 27 237d 2011-09-17 +1d
Scram # 46559
2011-01-21 2011-01-24 4 221d - -
Unscheduled
2010-06-13 2010-06-14 2 57d - -
Scheduled
2010-03-14 2010-04-17 35 487d 2010-03-13 +1d
Scheduled
2008-09-21 2008-11-12 53 84d 2008-09-20 +1d
Unscheduled
2008-06-27 2008-06-29 3 397d - -
Scheduled SGR/Major
2007-03-11 2007-05-27 78 448d 2007-03-10 +1d
Unscheduled
2005-12-17 2005-12-18 2 60d - -
Scheduled
2005-09-18 2005-10-18 31 312d 2005-09-17 +1d
Unscheduled
2004-10-19 2004-11-10 23 191d - -
Scheduled
2004-03-07 2004-04-11 36 515d 2004-03-06 +1d
Scheduled
2002-09-14 2002-10-09 26 192d 2002-09-14 0d
Unscheduled
2002-03-05 2002-03-06 2 323d - -
Scheduled
2001-03-10 2001-04-16 38 41d 2001-03-10 0d
Unscheduled
2001-01-24 2001-01-28 5 242d - -
Unscheduled
2000-05-26 2000-05-27 2 204d - -
Scheduled
1999-09-18 1999-11-04 48 - 1999-09-18 0d
Page created in 0.100 seconds with 7 queries.