?
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
?
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.
171
Current Run
days
#50 of 95
Mid Quartile
?
Longest recorded period of continuous operation between outages.
742
Record Run
days
#7 of 95
Top Quartile
?
Breaker-to-Breaker runs — continuous operation exceeding the cycle-adjusted threshold (612 days for this 24-month cycle unit) with no trips to 0% power.
1
B2B Runs
#84 of 87
Bottom Quartile
?
Lifetime capacity factor: average power level across all recorded days (100% = always at full power). Ranked against all NRC-tracked units.
83.5%
Capacity Factor
#90 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.
10.15 TWh
Net Generation
EIA-923 · 12 mo to 2026-06
?
Community rating score (Bayesian-adjusted). Based on 55 votes. Ranked against all rated facilities.
44.2
Rating
55 votes
#85 of 97
Bottom Quartile
?
Total NRC-reported scram events (emergency reactor shutdowns). Ranked fleet-wide — fewer scrams = better rank.
29
Scrams
#94 of 94
Bottom Quartile
?
Years since commercial operation began. License remaining: 18.1 years.
41.2
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.OnlineReduced PowerCoastdownPower AscensionRefueling Outage
Estimated reactivity remaining in Grand Gulf 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 Mar 28, 2026
Grand Gulf 1 is 167 days into its current fuel cycle with an estimated 75.5% of its fuel left. Its typical cycle runs about 669 days.
Fresh — 100%
Refuel — 0%
75.5% remaining
Fresh fuel
Cycle progress
167 / 669 days
EFPD remaining
505 days
Effective burn
164 EFPD
Burn deficit
3.1 FPD
Grand Gulf 1 is early in its fuel cycle with 505 EFPD of reactivity remaining. Refuel is not expected for many months.
Historical Burn-Down (15 completed cycles)
Avg refuel point
20.2% remaining
Avg refuel (3yr)
2.8% remaining
Deepest burn
1.8% (2014-03 → 2016-02)
Most margin
37.2% (2016-03 → 2018-04)
Last 5 cycles at refuel
37%
2016-03
24%
2018-07
19%
2020-05
10%
2022-05
3%
2024-03
~21% coastdown (this unit)
Operational Excellence Score Subscribers
Grand Gulf 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)
100%
Current
86.5%
365-Day Avg
#80
of 94 plants
Min: 0%
Max: 100%
56 days <80%
Breaker-to-Breaker Runs 1 run
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.
Grand Gulf 1 has logged 1 breaker-to-breaker run, continuous stretches from one refueling to the next with no trip to zero power. Its longest ran 636 days, and its runs average 636 days.
636
Best Run (days)
RF17 (2010-05-25) → RF18 (2012-02-20)
636
Avg Run (days)
Scram History 29 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.
Grand Gulf 1 has recorded 29 reactor scrams, or emergency shutdowns, since 2011 (15 automatic, 14 manual). On average the unit was back to full power about 17.4 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.
Grand Gulf 1 has completed 16 scheduled refueling outages on record, averaging 45 days each. The most recent, in Feb 2026, ran 41 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 Grand Gulf 1 has run at an average of 86.5% 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, Grand Gulf 1 has spent 724 days in scheduled refueling outages and 528 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.
Grand Gulf 1 has operated for about 41.2 years and averaged a 83.5% lifetime capacity factor, generating roughly 268.7 TWh of electricity. Its longest unbroken run reached 742 days.
Lifecycle & Tenure
Operating Age: 41.2 Yrs
Build Time: 10.8 Yrs
Lic. Remaining: 18.1 Yrs
Production & Power
Lifetime CF: 83.5%
Efficiency: 31.8%
Generated: 268.7 TWh
Reliability & Outages
Record Run: 742 Days
Refuelings: 16
Avg Startup: 12.4 Days
NukeWorker Member Ratings 55 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
13 (23%)
Average
17 (30%)
Below Average
25 (45%)
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.
32.0083, -91.0492
Location & Contact
Physical address, phone number, and website for this facility. Use the directions link to get driving directions via Google Maps.
Phone:
(601) 437-2800
Website:
http://www.entergy-nuclear.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, MS
Unemployment Benefits MS
Maximum state unemployment insurance benefits for MS. Actual benefits depend on your earnings history and may be lower than the maximum. Data as of Jan 2026.
$235
Max Weekly
26
Max Weeks
$6,110
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.
![The entangled "spaghetti" mess of retrieval after a shattered blade](https://www.nukeworker.com/pictures/albums/userpics/10127/thumb_retrieval2.jpg "The entangled "spaghetti" mess of retrieval after a shattered blade
Keywords: Grand Gulf Nuclear Power Plant
3148 views")
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.
ETR
Entergy Corporation
NYSE
$105.33
▼ -0.40 (-0.38%)
Previous Close
105.73
Day's Range
104.87 – 107.39
52-Week Range
87.38 – 118.45
Volume
4,179,374
Delayed quote as of Sep 11, 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:
BWR
Containment:
BWR-MARK 3
NSS Supplier:
GE 6
Thermal Power:
4408 MWt
Net Capacity:
1401 MWe
Efficiency:
31.8%
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 #:
05000416
License #:
NPF-29
License Type:
OL-FP
Const. Permit:
1974-09-04
Operating Lic:
1984-11-01
Commercial Op:
1985-07-01
License Renewed:
2016-12-01
License Exp:
2044-11-01
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:
ESC
— East South Central
Balancing Authority:
MISO
— Midcontinent Independent System Operator (ISO/RTO)
Market Structure:
Regulated
— Rate-regulated utility (cost-of-service pricing)