?
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.
31
Excellence
#80 of 93
Bottom Quartile
?
Current reactor power level from the most recent NRC daily report.
100%
Power
ONLINE
?
Days of continuous operation since the last outage ended. Ranked against all operating units.
280
Current Run
days
#42 of 95
Mid Quartile
?
Longest recorded period of continuous operation between outages.
528
Record Run
days
#87 of 95
Bottom Quartile
?
Breaker-to-Breaker runs — continuous operation exceeding the cycle-adjusted threshold (443 days for this 18-month cycle unit) with no trips to 0% power.
5
B2B Runs
#39 of 87
Mid Quartile
?
Lifetime capacity factor: average power level across all recorded days (100% = always at full power). Ranked against all NRC-tracked units.
85.8%
Capacity Factor
#85 of 95
Bottom Quartile
?
Net electricity actually generated over the most recent 12 months reported by the U.S. Energy Information Administration (Form EIA-923). These are authoritative actuals, not an estimate.
9.86 TWh
Net Generation
EIA-923 · 12 mo to 2026-06
?
Community rating score (Bayesian-adjusted). Based on 33 votes. Ranked against all rated facilities.
66.8
Rating
33 votes
#5 of 97
Top Quartile
?
Total NRC-reported scram events (emergency reactor shutdowns). Ranked fleet-wide — fewer scrams = better rank.
9
Scrams
#68 of 94
Mid Quartile
?
Years since commercial operation began. License remaining: 18.1 years.
41.7
Operating Age
years
18.1 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.OnlinePower AscensionForced Outage
Estimated reactivity remaining in Callaway'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 Jul 8, 2025
Callaway is 423 days into its current fuel cycle with an estimated 17.2% of its fuel left. Its typical cycle runs about 487 days.
Fresh — 100%
Refuel — 0%
17.2% remaining
Approaching refuel
Cycle progress
423 / 487 days
EFPD remaining
84 days
Effective burn
403 EFPD
Burn deficit
19.7 FPD
Callaway is approaching refuel. Coastdown decisions are being weighed; the next outage is likely within months.
This unit has accumulated 19.7 FPD of unburned fuel from cycle downtime — that's free margin to extend the cycle if operators want.
This unit has accumulated 19.7 FPD of unburned fuel from cycle downtime — that's free margin to extend the cycle if operators want.
Historical Burn-Down (17 completed cycles)
Avg refuel point
4.7% remaining
Avg refuel (3yr)
0.0% remaining
Deepest burn
0.0% (1999-11 → 2001-04)
Most margin
51.4% (2020-12 → 2022-04)
Last 5 cycles at refuel
5%
2017-12
0%
2019-05
51%
2020-12
3%
2022-05
0%
2023-11
~2% coastdown (this unit)
Composite Operational Excellence Score for Callaway — average percentile rank across 7 publicly observable metrics in three sub-scores: Reliability (capacity factor, forced outage days, B2B avg streak), Efficiency (fuel utilization, refuel duration), and Discipline (startup duration, scram count). Toggle the time window (3yr / 5yr / Lifetime) to see how this unit's standing shifts. Each dimension percentile-ranked across the active US fleet. Sub-score = average of components. Composite = average of the three sub-scores.
NukeWorker's Operational Excellence Score 5-yr composite · ranks 80 of 93 →
NukeWorker scores Callaway's operational excellence at 31 out of 100 over the past five years, ranking it 80 of 93 reactors in the active US fleet. The score blends reliability, efficiency, and operating discipline drawn from public performance data.
Time window
5-yr trend:
Stable vs 2025
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Capacity Factor (365-Day)
100%
Current
94.7%
365-Day Avg
#32
of 94 plants
Min: 0%
Max: 100%
21 days <80%
Breaker-to-Breaker Runs 5 runs
Breaker-to-breaker runs measure continuous operation between refueling outages using a cycle-adjusted threshold (90% of cycle length minus RFO duration). An active streak means the unit has been running continuously since the last refueling with no trips to 0% power.
Callaway has logged 5 breaker-to-breaker runs, continuous stretches from one refueling to the next with no trip to zero power. Its longest ran 521 days, and its runs average 499 days.
521
Best Run (days)
RF15 (2007-05-09) → RF16 (2008-10-11)
499
Avg Run (days)
★ Double breaker-to-breaker
RF17 → RF18 → RF19
All Runs
| 2017-12-18 | 2019-04-01 | 469 days | RF22 → RF23 |
| 2016-05-10 | 2017-10-07 | 515 days | RF21 → RF22 |
| 2011-11-25 | 2013-04-09 | 501 days | RF18 → RF19 |
| 2010-06-12 | 2011-10-16 | 491 days | RF17 → RF18 |
| 2007-05-09 | 2008-10-11 | 521 days | RF15 → RF16 |
Scram History 9 events since 2011
Automatic and manual reactor scram (emergency shutdown) events reported to the NRC since 2011. Includes event dates, trip type, and average recovery time. Click the title to view the full fleet scram dashboard.
Callaway has recorded 9 reactor scrams, or emergency shutdowns, since 2011 (9 automatic, 0 manual). On average the unit was back to full power about 8.1 days after each trip.
Outage Duration Trend
?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.
Callaway has completed 18 scheduled refueling outages on record, averaging 51 days each. The most recent, in Mar 2025, ran 99 days.
Power History (12-Month)
?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 Callaway has run at an average of 94.7% 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
?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, Callaway has spent 919 days in scheduled refueling outages and 173 days in forced or unplanned outages. Taller bars mark the years with the most downtime.
Facility Statistics
Key performance and lifecycle metrics calculated from NRC operational data. Includes operating age, construction timeline, capacity factor, efficiency, generation totals, and reliability records.
Callaway has operated for about 41.7 years and averaged a 85.8% lifetime capacity factor, generating roughly 253.1 TWh of electricity. Its longest unbroken run reached 528 days.
Lifecycle & Tenure
Operating Age: 41.7 Yrs
Build Time: 8.7 Yrs
Lic. Remaining: 18.1 Yrs
Production & Power
Lifetime CF: 85.8%
Efficiency: 33.4%
Generated: 253.1 TWh
Reliability & Outages
Record Run: 528 Days
Refuelings: 18
Avg Startup: 4.3 Days
NukeWorker Member Ratings 33 votes
Community ratings from NukeWorker members. Vote to share your experience working at this facility. Score uses a Bayesian average that accounts for vote count — facilities with few votes are pulled toward the fleet average, so rankings reflect confidence, not just raw percentages.
Above Average
23 (69%)
Average
8 (24%)
Below Average
2 (6%)
Facility Map
Interactive satellite map showing the facility's geographic location. Marker color indicates current status: green for online, red for offline, orange for reduced power. Click the header to open in Google Maps satellite view.
38.7594, -91.7855
Location & Contact
Physical address, phone number, and website for this facility. Use the directions link to get driving directions via Google Maps.
Phone:
(573) 676-8000
Website:
http://www.ameren.com/
Per Diem Rates FY 2026
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, MO
Unemployment Benefits MO
Maximum state unemployment insurance benefits for MO. Actual benefits depend on your earnings history and may be lower than the maximum. Data as of Jan 2026.
$320
Max Weekly
20
Max Weeks
$6,400
Max Total
7-day waiting period before benefits begin
Photos
Photos of this facility from the NukeWorker photo gallery. Click the header or any photo to browse the full album.
Ownership & Construction
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.
AEE
Ameren Corporation
NYSE
$106.47
▲ +0.06 (+0.06%)
Previous Close
106.41
Day's Range
106.12 – 106.97
52-Week Range
96.57 – 118.32
Volume
1,623,544
Delayed quote as of Sep 4, 2026 4:00 PM ET.
Source: Yahoo Finance.
Full quote on Yahoo Finance
Technical Specs
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:
PWR
Containment:
PWR-DRYAMB
NSS Supplier:
WEST 4LP
Thermal Power:
3565 MWt
Net Capacity:
1190 MWe
Efficiency:
33.4%
Status:
Operating
Licensing
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 #:
05000483
License #:
NPF-30
License Type:
OL-FP
Const. Permit:
1976-04-16
Operating Lic:
1984-10-18
Commercial Op:
1984-12-19
License Renewed:
2015-03-06
License Exp:
2044-10-18
Market & Region
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:
SERC
— SERC Reliability Corporation
Census Region:
WNC
— West North Central
Balancing Authority:
MISO
— Midcontinent Independent System Operator (ISO/RTO)
Market Structure:
Regulated
— Rate-regulated utility (cost-of-service pricing)