LaSalle 1 — Nuclear Reactor Data & Live Status

Live reactor status, daily power data, outage history & performance charts, scram history, capacity factor & statistics, community ratings, technical specifications, NRC licensing data, photos, nearby jobs, satellite map, contact information, and per diem rates for LaSalle 1.

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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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Current reactor power level from the most recent NRC daily report.
100%
Power
ONLINE
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Days of continuous operation since the last outage ended. Ranked against all operating units.
102
Current Run
days
#81 of 95
Bottom Quartile
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Longest recorded period of continuous operation between outages.
740
Record Run
days
#9 of 95
Top Quartile
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Breaker-to-Breaker runs — continuous operation exceeding the cycle-adjusted threshold (628 days for this 24-month cycle unit) with no trips to 0% power.
4
B2B Runs
#55 of 87
Mid Quartile
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Lifetime capacity factor: average power level across all recorded days (100% = always at full power). Ranked against all NRC-tracked units.
94.1%
Capacity Factor
#9 of 95
Top Quartile
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Net electricity actually generated over the most recent 12 months reported by the U.S. Energy Information Administration (Form EIA-923), summed across every unit at this plant. These are authoritative actuals, not an estimate.
18.49 TWh
Net Generation
EIA-923 · 12 mo to 2026-06 · plant total
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Community rating score (Bayesian-adjusted). Based on 33 votes. Ranked against all rated facilities.
43
Rating
33 votes
#87 of 97
Bottom Quartile
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Total NRC-reported scram events (emergency reactor shutdowns). Ranked fleet-wide — fewer scrams = better rank.
6
Scrams
#32 of 94
Mid Quartile
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Years since commercial operation began. License remaining: 15.6 years.
42.7
Operating Age
years
15.6 yrs remaining

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.
Oct2025NovDecJan2026FebMarAprMayJunJulAugSepOnline: Sep 9, 2025 to Oct 18, 2025Reduced Power: Oct 19, 2025Online: Oct 20, 2025 to Nov 2, 2025Scram: Nov 3, 2025 to Nov 4, 2025Reduced Power: Nov 5, 2025 to Nov 6, 2025Online: Nov 7, 2025 to Dec 3, 2025Reduced Power: Dec 4, 2025 to Dec 5, 2025Online: Dec 6, 2025 to Dec 25, 2025Coastdown: Dec 26, 2025 to Dec 28, 2025Scram: Dec 29, 2025 to Dec 31, 2025Coastdown: Jan 1, 2026Power Ascension: Jan 2, 2026 to Jan 8, 2026Coastdown: Jan 9, 2026Power Ascension: Jan 10, 2026 to Jan 11, 2026Coastdown: Jan 12, 2026 to Jan 15, 2026Power Ascension: Jan 16, 2026Coastdown: Jan 17, 2026 to Jan 19, 2026Power Ascension: Jan 20, 2026 to Jan 21, 2026Coastdown: Jan 22, 2026 to Feb 8, 2026Refueling Outage (L1R21): Feb 9, 2026 to Feb 27, 2026L1R21Power Ascension: Feb 28, 2026 to Mar 1, 2026Online: Mar 2, 2026 to Mar 13, 2026Reduced Power: Mar 14, 2026 to Mar 16, 2026Online: Mar 17, 2026 to May 2, 2026Reduced Power: May 3, 2026Online: May 4, 2026 to May 25, 2026Reduced Power: May 26, 2026Forced Outage: May 27, 2026 to May 30, 2026Reduced Power: May 31, 2026Online: Jun 1, 2026Power Ascension: Jun 2, 2026Online: Jun 3, 2026 to Sep 9, 2026Scram (reactor trip): Nov 2, 2025Scram (reactor trip): Dec 28, 2025Today
OnlineReduced PowerCoastdownPower AscensionRefueling OutageForced OutageScramScram (reactor trip)
Full history & analysis →

Operational Excellence Score Subscribers

LaSalle 1 is rated 0 to 100 on how well it actually runs, scored against every other operating reactor in the US fleet from its own operating record. Subscribers see the score, the three sub-scores behind it, and each of the seven measured inputs.

  • This unit's composite score and fleet rank
  • Reliability, Efficiency and Discipline sub-scores
  • All seven measured inputs, with fleet percentiles
  • Rank against comparable units, not just the fleet
  • Three-year, five-year and lifetime windows
  • Five-year trend, and every other operating US reactor

Included with every outage subscription and with NukeWorker Gold membership. Trading the outage rather than working it? The same record, cut by power market, is on NukeGryd.

Capacity Factor (365-Day)

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100%
Current
89%
365-Day Avg
#89
of 94 plants
Min: 0% Max: 100% 40 days <80%

Outage Duration Trend

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Scheduled refueling outage durations over time. Green bars are below average, yellow near average, red above. Dashed line shows the plant's historical average. Shorter outages mean better execution.
LaSalle 1 has completed 13 scheduled refueling outages on record, averaging 23 days each. The most recent, in Feb 2026, ran 19 days.

Power History (12-Month)

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Daily power output as a percentage of rated capacity over the past 365 days. Green segments indicate full power (90%+), yellow shows reduced output, and red indicates significant power reductions or shutdowns.
Over the past 12 months LaSalle 1 has run at an average of 89% of rated power. On the chart, green stretches are full-power running and dips toward zero mark reduced output or outages.

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, LaSalle 1 has spent 299 days in scheduled refueling outages and 107 days in forced or unplanned outages. Taller bars mark the years with the most downtime.

Facility Statistics

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Key performance and lifecycle metrics calculated from NRC operational data. Includes operating age, construction timeline, capacity factor, efficiency, generation totals, and reliability records.
LaSalle 1 has operated for about 42.7 years and averaged a 94.1% lifetime capacity factor, generating roughly 258.9 TWh of electricity. Its longest unbroken run reached 740 days.
Lifecycle & Tenure
Operating Age: 42.7 Yrs
Build Time: 10.3 Yrs
Lic. Remaining: 15.6 Yrs
Production & Power
Lifetime CF: 94.1%
Efficiency: 31.9%
Generated: 258.9 TWh
Reliability & Outages
Record Run: 740 Days
Refuelings: 13
Avg Startup: 4.1 Days

Location & Contact

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Physical address, phone number, and website for this facility. Use the directions link to get driving directions via Google Maps.
Address:
2601 North 21st Road
Marseilles, IL 61341, USA
Get Directions
Phone: (815) 357-6761

Per Diem Rates FY 2026

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Per diem covers lodging and meals & incidental expenses (M&IE) for government and contractor travel near this facility. Rates are from GSA for FY 2026.
$110
Lodging/Night
$68
M&IE/Day
$178
Total/Day
Standard Rate, IL

Unemployment Benefits IL

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Maximum state unemployment insurance benefits for IL. Actual benefits depend on your earnings history and may be lower than the maximum. Data as of Jan 2026.
$859
Max Weekly
26
Max Weeks
$22,334
Max Total
7-day waiting period before benefits begin

Ownership & Construction

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The utility or company that owns and operates the facility, the architect-engineer responsible for plant design, and the primary construction contractor. Click names to view all facilities by that entity on the map.
Owner/Operator: Constellation Energy
Architect Engineer: S&L
Constructor: CWE
CEG Constellation Energy Corporation NasdaqGS
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Previous Close 299.05
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Volume 538,597
Delayed quote as of Sep 9, 2026 11:35 AM ET. Source: Yahoo Finance. Full quote on Yahoo Finance

Technical Specs

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Reactor design specifications including type (PWR/BWR), containment design, nuclear steam supply system manufacturer, thermal and electrical power ratings, and current operational status.
Reactor Type: BWR
Containment: BWR-MARK 2
NSS Supplier: GE 5
Thermal Power: 3546 MWt
Net Capacity: 1131 MWe
Efficiency: 31.9%
Status: Operating

Licensing

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NRC licensing history including docket number, license type and number, construction permit date, operating license issuance, commercial operation date, license renewal, and expiration date.
Docket #: 05000373
License #: NPF-11
License Type: OL-FP
Const. Permit: 1973-09-10
Operating Lic: 1982-04-17
Commercial Op: 1984-01-01
License Renewed: 2016-10-19
License Exp: 2042-04-17

Market & Region

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EIA market and grid-region classifications: NERC reliability region, U.S. Census region, balancing authority responsible for grid operations, and whether the unit operates as a rate-regulated utility or a competitive merchant generator. Hover any value for the full name.
NERC Region: RFC — Reliability First Corporation
Census Region: ENC — East North Central
Balancing Authority: PJM — PJM Interconnection (ISO/RTO)
Market Structure: Merchant — Competitive generator selling into wholesale markets