?
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.
43
Excellence
#60 of 94 →
Mid Quartile
?
Days of continuous operation since the last outage ended. Clean run (no forced outages since last refueling).
175
Current Run
days ✔
?
Longest recorded period of continuous operation between outages (2007-10-24 to 2009-04-20).
544
Record Run
days
?
Breaker-to-Breaker runs — continuous operation exceeding the cycle-adjusted threshold (451 days for this 18-month cycle unit) with no trips to 0% power.
9
B2B Runs
?
Lifetime capacity factor: average power level across all recorded days (100% = always at full power).
90.7%
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.
6
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.
99.2%
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.
• 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
43/100
Mid Quartile · #60/94
5-year window
Beaver Valley 1 ranks #60 of 94 active US units on NukeWorker's Operational Excellence Score over the 5-year window. Strongest area: Fuel Utilization (80th percentile). Weakest: Refuel Duration (20th percentile).
Reliability
45
Capacity factor + Forced outages + B2B streaks
Efficiency
50
Fuel utilization + Refuel duration
Discipline
34
Startup duration + Scram count
Cohort Rankings
apples-to-apples comparison within each peer group
Reactor type:
#42 of 61
PWR
Containment:
#35 of 48
Dry Ambient (PWR)
Cycle length:
#35 of 54
18-month cycle
Fleet rank above (60 of 94) compares all active US units; cohort ranks compare only against units sharing this property.
Per-dimension breakdown (7 metrics)
Capacity Factor
53th
91.6% (higher better, Reliability)
Forced Outage Days/yr
55th
3.2d (lower better, Reliability)
B2B Avg Streak
27th
504d (higher better, Reliability)
Fuel Utilization
80th
98.7% (higher better, Efficiency)
Refuel Duration
20th
39d (lower better, Efficiency)
Startup Duration
39th
5.0d (lower better, Discipline)
Scrams (5-year)
30th
0.6/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:
Stable vs 2025
Compare Beaver Valley 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 Nov 21, 2025
66.2% remaining
173 / 508 days
1.0 FPD margin
Avg refuel: 2.3%
Avg refuel (3yr): 0.8%
Deepest burn: 0.0% (2003-04 → 2004-10)
Most margin: 11.5% (2004-11 → 2006-02)
?
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
|
2025-10-12 | 2025-11-20 | 40 | 509d | 2025-10-08 | +4d |
|
Scheduled
|
2024-04-13 | 2024-05-21 | 39 | 512d | 2024-04-13 | 0d |
|
Scheduled
|
2022-10-09 | 2022-11-18 | 41 | 101d | 2022-10-09 | 0d |
|
Unscheduled
|
2022-06-24 | 2022-06-30 | 7 | 3d | - | - |
|
Scram
# 55943
|
2022-06-16 | 2022-06-21 | 6 | 402d | - | - |
|
Scheduled
|
2021-04-11 | 2021-05-10 | 30 | 523d | 2021-04-04 | +7d |
|
Scheduled
|
2019-10-13 | 2019-11-05 | 24 | 522d | 2019-10-13 | 0d |
|
Scheduled
|
2018-04-15 | 2018-05-09 | 25 | 155d | 2018-04-14 | +1d |
|
Scram
# 53056
|
2017-11-08 | 2017-11-11 | 4 | 380d | - | - |
|
Unscheduled
Startup Hold
|
2016-10-23 | 2016-10-24 | 2 | 2d | - | - |
|
Scheduled
|
2016-09-24 | 2016-10-21 | 28 | 468d | 2016-09-30 | -6d |
|
Unscheduled
|
2015-06-13 | 2015-06-14 | 2 | 21d | - | - |
|
Scheduled
|
2015-04-25 | 2015-05-23 | 29 | 9d | 2015-04-06 | +19d |
|
Scram
# 50985
|
2015-04-16 | 2015-04-16 | 1 | 443d | - | - |
|
Scram
# 49697
|
2014-01-07 | 2014-01-28 | 22 | 60d | - | - |
|
Scram
# 49505
|
2013-11-06 | 2013-11-08 | 3 | 3d | - | - |
|
Scheduled
|
2013-09-30 | 2013-11-03 | 35 | 508d | 2013-09-30 | 0d |
|
Scheduled
|
2012-04-09 | 2012-05-10 | 32 | 360d | 2012-04-07 | +2d |
|
Unscheduled
|
2011-04-14 | 2011-04-15 | 2 | 162d | - | - |
|
Scheduled
|
2010-10-02 | 2010-11-03 | 33 | 499d | 2010-10-04 | -2d |
|
Scheduled
|
2009-04-20 | 2009-05-21 | 32 | 544d | 2009-04-20 | 0d |
|
Scheduled
|
2007-09-24 | 2007-10-24 | 31 | 380d | 2007-09-24 | 0d |
|
Unscheduled
|
2006-09-08 | 2006-09-09 | 2 | 10d | - | - |
|
Unscheduled
|
2006-08-26 | 2006-08-29 | 4 | 91d | - | - |
|
Unscheduled
|
2006-05-27 | 2006-05-27 | 1 | 38d | - | - |
|
Scheduled
SGR/Major
|
2006-02-13 | 2006-04-19 | 66 | 456d | 2006-02-12 | +1d |
|
Scheduled
|
2004-10-18 | 2004-11-14 | 28 | 339d | 2004-10-17 | +1d |
|
Unscheduled
|
2003-11-14 | 2003-11-14 | 1 | 199d | - | - |
|
Scheduled
|
2003-03-08 | 2003-04-29 | 53 | 10d | 2003-03-08 | 0d |
|
Unscheduled
|
2003-02-25 | 2003-02-26 | 2 | 95d | - | - |
|
Unscheduled
|
2002-11-12 | 2002-11-22 | 11 | 338d | - | - |
|
Unscheduled
|
2001-12-08 | 2001-12-09 | 2 | 29d | - | - |
|
Unscheduled
|
2001-11-07 | 2001-11-09 | 3 | 30d | - | - |
|
Scheduled
|
2001-09-01 | 2001-10-08 | 38 | 69d | 2001-09-01 | 0d |
|
Unscheduled
|
2001-06-23 | 2001-06-24 | 2 | 56d | - | - |
|
Unscheduled
|
2001-04-20 | 2001-04-28 | 9 | 288d | - | - |
|
Unscheduled
|
2000-07-06 | 2000-07-06 | 1 | 79d | - | - |
|
Unscheduled
|
2000-04-18 | 2000-04-18 | 1 | 11d | - | - |
|
Scheduled
|
2000-02-16 | 2000-04-07 | 52 | 159d | 2000-02-16 | 0d |
|
Unscheduled
|
1999-09-10 | 1999-09-10 | 1 | 2d | - | - |
|
Unscheduled
|
1999-09-07 | 1999-09-08 | 2 | 124d | - | - |
|
Unscheduled
|
1999-05-02 | 1999-05-06 | 5 | 2d | - | - |
|
Unscheduled
|
1999-04-13 | 1999-04-30 | 18 | 47d | - | - |
|
Unscheduled
|
1999-02-15 | 1999-02-25 | 11 | 21d | - | - |
|
Unscheduled
|
1999-01-24 | 1999-01-25 | 2 | - | - | - |
Page created in 0.088 seconds with 7 queries.