Arkansas Nuclear 1

Online · 100% power

Entergy·Russellville, AR·PWR·833 MWe

Data refreshed 5.4h ago Rx Status: Oct 14, 2026 at 5:20 AM (M-F)

Outage History Daily Power Log Get alerts

Reactor Status Timeline

Online NRC data, Mon to Fri ? Actual daily reactor status from NRC reports (Mon to Fri) and the current state. What is coming -- the utility's published Scheduled outage and NukeWorker's model Projection -- is part of a subscription. Colored by status. How far ahead you can see depends on your plan.
Nov2025DecJan2026FebMarAprMayJunJulAugSepOctRefueling Outage: Oct 14, 2025 to Nov 13, 2025Power Ascension: Nov 14, 2025 to Nov 17, 2025Online: Nov 18, 2025 to Oct 14, 2026Today
OnlinePower AscensionRefueling Outage
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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.
   
Excellence
Rank locked · 93 units
Subscribers
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Days of continuous operation since the last outage ended (Started 2025-11-13). Clean run (no forced outages since last refueling).
335
Current Run
days ✔
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Longest recorded period of continuous operation between outages (2010-04-26 to 2011-10-17).
539
Record Run
days
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Breaker-to-Breaker runs — continuous operation exceeding the cycle-adjusted threshold set for this unit with no trips to 0% power.
6
B2B Runs
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Lifetime capacity factor: average power level across all recorded days (100% = always at full power).
88.5%
Capacity Factor
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Net electricity actually generated over the most recent 12 months reported by the U.S. EIA (Form EIA-923), summed across every unit at this plant. Authoritative actuals, not an estimate.
14.08 TWh
Net Generation
EIA-923 · 12 mo to 2026-07 · plant total
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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.
16.3
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.
96.8%
Fuel Utilization
3yr avg

Reactor Status

Current Reactor Status Oct 14, 2026

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Current power output from NRC daily reactor status reports, updated Monday through Friday, except federal holidays. The gauge shows power level as a percentage of rated capacity. The sparkline shows the last 14 days of power history. Click to view the full unit dashboard.
Arkansas Nuclear 1 is Online at 100% of rated power as of Oct 14, 2026. Over the last 14 reported days it has run between 100% and 100% power.
Arkansas Nuclear 1 is Online Get alerts
100
PERCENT
0 100 200 300 400 500 600 700 800 833 RATED CAPACITY (833 MWe) 833 MWe
Current:
833 MWe
Powering 666,400 homes
Rated Capacity:
833 MWe
666,400 homes
14-Day Power History
Oct 1 Oct 14

Capacity Factor (365-Day)

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100%
Current
90.9%
365-Day Avg
#33
of 94 plants
Min: 0% Max: 100% 34 days <80%

Outage Days by Year

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Total days spent in outage each year, split by scheduled refueling (blue) and forced/unplanned (red). Lower totals indicate better reliability and outage execution. Hover for details.
Across its recorded history, Arkansas Nuclear 1 has spent 799 days in scheduled refueling outages and 194 days in forced or unplanned outages. Taller bars mark the years with the most downtime.
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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

Arkansas Nuclear 1 has 47 outages plotted here, averaging 21 days each. The most recent, in Oct 2025, was a scheduled refueling outage lasting 34 days.
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Scheduled refueling outage durations over time. Green bars are at or below this unit's average, amber up to 30% above it, red beyond that. The dashed line is the average. Shorter outages mean better execution.

Refueling Duration Trend

Arkansas Nuclear 1 has completed 18 scheduled refueling outages on record, averaging 44 days each. The most recent, in Oct 2025, ran 34 days.
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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

After a refueling outage, Arkansas Nuclear 1 takes about 3 days to climb from first power back to full power. That average is drawn from 18 startups on record, and the most recent took 4 days.
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Daily reactor power over the 120 days before each scheduled refueling outage, one line per refueling, lined up on the day the outage began. A coastdown is the slow decline as the fuel runs out near the end of a cycle. The highlighted line is the most recent refueling and fainter lines are older. Counts and medians cover coastdowns of a week or longer. A shutdown straight from full power, with no decline ahead of it, is what a forced outage looks like.

Coastdown Before Refueling

8 of 18 refuelings 22 days median 76% power at shutdown 1.0% per day
Arkansas Nuclear 1 coasted down for a week or longer before 8 of its 18 refuelings on record. Those coastdowns ran a median of 22 days and ended near 76% power. The most recent refueling, in Oct 2025, followed a 24-day coastdown from 97% to 70%.
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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 Nov 14, 2025

34.6% remaining 1.3 FPD margin
Arkansas Nuclear 1 has an estimated 34.6% of its fuel left. Across its last 17 cycles, it has refueled with an average of 4.0% remaining.
Avg refuel: 4.0% Avg refuel (3yr): 3.2% Deepest burn: 0.0% (2001-04 → 2002-10) Most margin: 14.3% (2016-12 → 2018-03)
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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

Over its operating life, Arkansas Nuclear 1 has run at about 88.5% of its rated capacity. Across the last 12 reported months it averaged 95.8%. On the chart, green stretches near the top are full-power running, amber marks reduced power (50 to 89%), and red drops toward zero are outages.
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Estimated reactivity remaining in Arkansas Nuclear 1's current fuel cycle, shown as a stylized fuel rod that drains as the cycle progresses. The cycle starts when the unit returns to power after its most recent refueling outage, and the gauge represents the fraction of that cycle's typical effective full-power days (EFPD) still available. Days at less than 100% power burn fuel proportionally — so a unit with significant downtime (high burn deficit) drains slower and ends with MORE reactivity left, giving operators margin to coast down (extend the cycle by reducing power) instead of refueling on the calendar. The dashed red line near the bottom marks the rough industry coastdown threshold (~15% remaining). Cycle target is the unit's median recent cycle length. Source: NRC daily reactor status reports cross-referenced against scheduled refuel outage history.

Fuel Burn Down Cycle since Nov 14, 2025

Arkansas Nuclear 1 is 333 days into its current fuel cycle with an estimated 34.6% of its fuel left. Its typical cycle runs about 507 days.
Fresh — 100%
25% 50% 75% COASTDOWN ~1% DAY 0 DAY 507
Refuel — 0%
34.6% remaining
Mid-cycle
Cycle progress
333 / 507 days
EFPD remaining
175 days
Effective burn
332 EFPD
Burn deficit
1.3 FPD
Arkansas Nuclear 1 is mid-cycle with healthy reactivity. Operators have flexibility to defer or advance the next refuel as needed.

Outage History & Daily Power Log

This table logs every recorded outage for Arkansas Nuclear 1, 47 in all since 1999. Of those, 18 were scheduled refueling outages and 29 were unplanned or forced. The typical outage lasted about 21 days. Where the Scheduled column shows (Model), the date is a NukeWorker projection because the utility had not published one.
Type ⇅ Actual Start ⇅ Actual End ⇅ Duration ⇅ Days Online ⇅ Scheduled Delta
Scheduled 1R32
2025-10-11 2025-11-13 34 13d 2025-10-08 +3d
Scram # 57949 Auto
2025-09-25 2025-09-28 4 290d - -
Unscheduled
2024-12-05 2024-12-09 5 200d - -
Scheduled 1R31
2024-04-27 2024-05-19 23 144d 2024-04-26 +1d
Unscheduled
2023-12-04 2023-12-05 2 291d - -
Scram # 56351 Auto
2023-02-15 2023-02-16 2 48d - -
Unscheduled
2022-11-25 2022-12-29 35 2d - -
Scheduled 1R30
2022-10-08 2022-11-23 47 311d 2022-10-08 0d
Scram # 55614 Auto
2021-11-30 2021-12-01 2 206d - -
Scheduled 1R29
2021-04-10 2021-05-08 29 24d 2021-04-10 0d
Scram # 55138 Manual
2021-03-15 2021-03-17 3 483d - -
Scheduled 1R28
2019-10-06 2019-11-18 44 289d 2019-09-16 +20d
Scram # 53793 Auto
2018-12-19 2018-12-21 3 176d - -
Unscheduled
2018-06-23 2018-06-26 4 5d - -
Scram # 53459 Manual
2018-06-17 2018-06-18 2 2d - -
Unscheduled
2018-06-13 2018-06-15 3 24d - -
Scram # 53404 Auto
2018-05-17 2018-05-20 4 2d - -
Scheduled 1R27
2018-03-24 2018-05-15 53 311d 2018-03-24 0d
Scram # 52710 Manual
2017-04-27 2017-05-17 21 136d - -
Scheduled 1R26SGR/Major
2016-09-24 2016-12-12 80 282d 2016-09-18 +6d
Scram # 51607 Manual
2015-12-16 2015-12-17 2 290d - -
Scheduled 1R25
2015-01-26 2015-03-01 35 528d 2015-01-25 +1d
Unscheduled
2013-08-15 2013-08-16 2 10d - -
Scheduled 1R24SGR/Major
2013-03-25 2013-08-05 134 491d 2013-03-24 +1d
Scheduled 1R23
2011-10-17 2011-11-20 35 539d 2011-10-16 +1d
Unscheduled
2010-04-19 2010-04-26 8 2d - -
Scheduled 1R22
2010-03-22 2010-04-17 27 406d 2010-04-20 -29d
Unscheduled
2009-02-08 2009-02-09 2 2d - -
Unscheduled
2009-02-06 2009-02-06 1 45d - -
Unscheduled
2008-12-21 2008-12-23 3 10d - -
Scheduled 1R21
2008-10-27 2008-12-11 46 533d 2008-10-26 +1d
Scheduled 1R20
2007-04-23 2007-05-13 21 480d 2007-04-22 +1d
Unscheduled
2005-12-27 2005-12-29 3 6d - -
Scheduled 1R19SGR/Major
2005-10-05 2005-12-21 78 473d 2005-10-04 +1d
Unscheduled
2004-06-12 2004-06-19 8 31d - -
Scheduled 1R18
2004-04-21 2004-05-12 22 133d 2004-04-20 +1d
Unscheduled
2003-11-16 2003-12-10 25 78d - -
Unscheduled
2003-08-30 2003-08-30 1 291d - -
Scheduled 1R17
2002-10-05 2002-11-12 39 437d 2002-10-05 0d
Unscheduled
2001-07-25 2001-07-25 1 108d - -
Scheduled 1R16
2001-03-17 2001-04-08 23 70d 2001-03-17 0d
Unscheduled
2001-01-06 2001-01-06 1 298d - -
Unscheduled
2000-03-14 2000-03-14 1 2d - -
Unscheduled
2000-02-05 2000-03-12 37 25d - -
Unscheduled
2000-01-08 2000-01-11 4 91d - -
Scheduled 1R15
1999-09-11 1999-10-09 29 249d 1999-09-11 0d
Unscheduled
1999-01-01 1999-01-05 5 - - -
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