Susquehanna 2 - Status & History

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

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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.
Oct2025NovDecJan2026FebMarAprMayJunJulAugSepOctOnline: Sep 18, 2025 to Oct 13, 2025Reduced Power: Oct 14, 2025 to Oct 25, 2025Online: Oct 26, 2025 to Oct 28, 2025Scram: Oct 29, 2025 to Oct 30, 2025Reduced Power: Oct 31, 2025 to Nov 3, 2025Online: Nov 4, 2025 to Nov 23, 2025Reduced Power: Nov 24, 2025Online: Nov 25, 2025 to Feb 13, 2026Reduced Power: Feb 14, 2026Online: Feb 15, 2026 to Jun 25, 2026Reduced Power: Jun 26, 2026Online: Jun 27, 2026 to Aug 7, 2026Reduced Power: Aug 8, 2026Online: Aug 9, 2026 to Sep 18, 2026Scram (reactor trip): Oct 28, 2025Today
OnlineReduced PowerScram⚡Scram (reactor trip)
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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
ranked of 93
Subscribers
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Days of continuous operation since the last outage ended. Clean run (no forced outages since last refueling).
323
Current Run
days ✔
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Longest recorded period of continuous operation between outages (2007-04-11 to 2009-04-07).
727
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.
4
B2B Runs
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Lifetime capacity factor: average power level across all recorded days (100% = always at full power).
89.5%
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.
19.54 TWh
Net Generation
EIA-923 · 12 mo to 2026-06 · plant total
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Total number of scheduled refueling outages detected in the historical data.
14
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.
7.3
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.
98.6%
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 measured 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
5-yr trend: 2021: 55/100 (#44/93)2022: 57/100 (#38/92)2023: 56/100 (#34/92)2024: 52/100 (#41/92)2025: 52/100 (#37/92)2026: 37/100 (#66/93) ↓ -14.5 pts vs 2025
Compare Susquehanna 2 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

Susquehanna 2 has 44 outages plotted here, averaging 18 days each. The most recent, in Oct 2025, was a unplanned outage lasting 2 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, Susquehanna 2 takes about 8 days to climb from first power back to full power. That average is drawn from 13 startups on record, and the most recent took 8 days.
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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 Jun 5, 2025

34.7% remaining 12.6 FPD margin
Susquehanna 2 has an estimated 34.7% of its fuel left. Across its last 13 cycles, it has refueled with an average of 6.4% remaining.
Avg refuel: 6.4% Avg refuel (3yr): 1.4% Deepest burn: 0.0% (2007-04 → 2009-04) Most margin: 18.0% (2011-07 → 2013-04)
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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, Susquehanna 2 has run at about 89.5% of its rated capacity. Across the last 12 reported months it averaged 98.1%. On the chart, flat stretches near the top are full-power running and drops to zero are outages.
This table logs every recorded outage for Susquehanna 2, 44 in all since 1999. Of those, 14 were scheduled refueling outages, 1 was planned maintenance and 29 were unplanned or forced. The typical outage lasted about 18 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
Scram # 58012
2025-10-29 2025-10-30 2 148d - -
Scheduled U2 22RIO
2025-03-24 2025-06-03 72 702d 2025-03-28 -4d
Scheduled U2 21RIO
2023-03-20 2023-04-22 34 63d 2023-03-20 0d
Unscheduled
2023-01-15 2023-01-16 2 105d - -
Unscheduled
2022-09-29 2022-10-02 4 350d - -
Scram # 55514
2021-10-12 2021-10-14 3 173d - -
Scheduled U2 20RIO
2021-03-22 2021-04-22 32 401d 2021-03-20 +2d
Scram # 54525
2020-02-14 2020-02-15 2 300d - -
Scheduled U2 19RIO
2019-03-23 2019-04-20 29 714d 2019-03-23 0d
Scheduled U2 18RIO
2017-03-04 2017-04-08 36 149d 2017-03-04 0d
Planned Mid-Cycle Planned
2016-10-02 2016-10-06 5 139d - -
Scram # 51925
2016-05-13 2016-05-16 4 356d - -
Scheduled # 50973 U2 17RIO
2015-04-11 2015-05-23 43 210d 2015-04-11 0d
Unscheduled
2014-09-06 2014-09-13 8 64d - -
Unscheduled
2014-06-26 2014-07-04 9 94d - -
Unscheduled
2014-03-21 2014-03-24 4 7d - -
Unscheduled
2014-03-02 2014-03-14 13 161d - -
Scram # 49342
2013-09-14 2013-09-22 9 109d - -
Scheduled U2 16RIO
2013-04-14 2013-05-28 45 109d 2013-04-15 -1d
Scram # 48607
2012-12-20 2012-12-26 7 2d - -
Scram # 48598
2012-12-16 2012-12-18 3 18d - -
Unscheduled
2012-11-28 2012-11-28 1 3d - -
Unscheduled
2012-11-21 2012-11-25 5 3d - -
Scram # 48496
2012-11-09 2012-11-18 10 149d - -
Unscheduled
2012-05-31 2012-06-13 14 284d - -
Scram # 47172
2011-08-20 2011-08-21 2 55d - -
Scheduled U2 15RIOSGR/Major
2011-04-05 2011-06-26 83 346d 2011-04-05 0d
Unscheduled
2010-04-24 2010-04-24 1 344d - -
Scheduled U2 14RIO
2009-04-07 2009-05-15 39 727d 2009-04-07 0d
Scheduled U2 13RIO
2007-03-04 2007-04-11 39 138d 2007-03-03 +1d
Unscheduled
2006-09-30 2006-10-17 18 149d - -
Unscheduled
2006-04-29 2006-05-04 6 323d - -
Unscheduled
2005-06-07 2005-06-10 4 39d - -
Unscheduled
2005-04-29 2005-04-29 1 17d - -
Unscheduled
2005-04-11 2005-04-12 2 20d - -
Scheduled U2 12RIO
2005-02-27 2005-03-22 24 680d 2005-02-26 +1d
Scheduled U2 11RIO
2003-03-08 2003-04-19 43 147d 2003-03-08 0d
Unscheduled
2002-10-01 2002-10-12 12 527d - -
Scheduled U2 10RIO
2001-03-10 2001-04-22 44 199d 2001-03-10 0d
Unscheduled
2000-08-18 2000-08-23 6 240d - -
Unscheduled
1999-12-18 1999-12-22 5 186d - -
Unscheduled
1999-06-09 1999-06-15 7 44d - -
Unscheduled
1999-04-26 1999-04-26 1 2d - -
Scheduled U2 9RIO
1999-03-13 1999-04-24 43 - 1999-03-13 0d
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