# US nuclear electricity, units and capacity

Dataset page: https://meplar.com/datasets/us-nuclear-electricity/

Snapshot: 14 October 2026. 50 US states and Washington, DC; chart 1990–2025; full annual series 1957–2025.

Full data CSV: https://meplar.com/downloads/us-nuclear-electricity/v1/us_nuclear_annual_1957_2025.csv
Chart/summary CSV: https://meplar.com/downloads/us-nuclear-electricity/v1/chart_data.csv
Desktop chart: https://meplar.com/downloads/us-nuclear-electricity/v1/chart.png
Mobile chart: https://meplar.com/downloads/us-nuclear-electricity/v1/chart_mobile.png
Complete package: https://meplar.com/downloads/us-nuclear-electricity/v1/us-nuclear-electricity.zip

## Package layout and reproduction

Extract the ZIP and enter meplar_energy/. This complete shared pipeline includes both nuclear/ and co2/ with their frozen raw inputs, full CSVs and reviewed chart variants. Both folders are necessary because build.py rebuilds both topics. With the versions in requirements.txt, run `python build.py`, then `python mobile.py`. No network is needed; do not run fetch_sources.py for this fixed snapshot. Rendering can depend on library/font versions; use supplied chart hashes to identify the reviewed originals.

## Source data and reuse

EIA numerical data are in the US public domain. Retain acknowledgement of EIA and the September 2026 Monthly Energy Review. EIA logos and protected third-party media are not included. Original Meplar charts and code are separate works; no new license for them is asserted here.

## Original source and method notes

## Source and permission
U.S. Energy Information Administration, Monthly Energy Review, September 2026, Table 8.1. Retrieved 2026-10-14 UTC.
- Data: https://www.eia.gov/totalenergy/data/browser/csv.php?tbl=T08.01
- Definitions/release: https://www.eia.gov/totalenergy/data/monthly/pdf/sec8.pdf
- Redistribution: https://www.eia.gov/about/copyrights_reuse.php
EIA expressly permits distribution of its public-domain data with acknowledgement. Includes numerical data and an original visualization, not EIA logos or third-party media.

## Files and cleaning
raw/eia_t08_01.csv is the exact downloaded table. us_nuclear_annual_1957_2025.csv retains all 69 annual rows, identified by YYYYMM ending in 13. Monthly rows are not summed. Nonnumeric unavailable values become empty cells; no interpolation or outlier deletion.
chart_data.csv selects every year 1990–2025 (36 rows). 1990 is objectively the highest year-end operable-unit count in the entire 1957–2025 series (112). Full history is provided to inspect this selection. 2025 is the last complete year; partial 2026 is excluded.

## Dictionary
- year: calendar year.
- operable_units_year_end: NUOUPUS, units licensed/equivalently permitted at year-end; includes some long shutdowns, not just units generating all year.
- net_summer_capacity_gw_year_end: NUGBPUS, million kW = GW, year-end net summer capability, not annual average.
- net_generation_twh: NUETPUS, million kWh / 1,000 = TWh, calendar-year net output.
- capacity_factor_pct_eia: NUCASUS, percent as published. Not charted; methodology changes in 2008 require care in subsequent analysis.
- nuclear_share_pct: NUETSUS, percent of electricity net generation, as published.
- *_index_1990_100: value / 1990 value × 100. Dimensionless indices share one axis, no dual axis.
Geography: 50 U.S. states and District of Columbia.

## Claims
1990: 576.862 TWh, 99.624 GW, 112 units.
2025: 784.781 TWh, 96.880 GW, 94 units.
Generation change = (784.781 / 576.862 − 1) × 100 = +36.0431091%.
Capacity change = (96.880 / 99.624 − 1) × 100 = −2.7543564%.
Count change = (94 / 112 − 1) × 100 = −16.0714286%.
Chart describes changes, not causation. Count is not generating capability. Index axis spans 60–150 with labelled baseline 100; it is a line plot, not a truncated bar. EIA can revise figures.

## Reproduce
From parent package directory run python build.py using requirements.txt. Archived inputs reproduce this snapshot without fetching updated data. PNG 2800 × 2000, SVG included. SHA256SUMS.txt in this download and the ZIP inventories the packaged files.