HDR Grosswelzheim
Reactor Data
Reactor Units
Every power reactor at this site as listed in the IAEA Power Reactor Information System (PRIS): reactor type and model, net electrical capacity, grid connection and commercial operation dates, and current status.
1 unit: 1 decommissioning completed.
| Unit | Type | Model | Net MWe | Construction | Grid | Commercial Op | Shutdown | Status |
|---|---|---|---|---|---|---|---|---|
| HDR Grosswelzheim | BWR | Superheated steam reactor | 25 | 1965-01-01 | 1970-08-02 | 1971-07-20 | Decommissioning Completed |
Capacity, milestones and suppliers
| Unit | Design MWe | Gross MWe | Thermal MWt | First Criticality | Reactor Supplier | Turbine Supplier | Notes |
|---|---|---|---|---|---|---|---|
| HDR Grosswelzheim | 23 | 27 | 100 | 1969-10-14 | ALLGEMEINE ELEKTRICITAETS GESELLSCHAFT, KRAFTWERK UNION AG | ALSTOM | Decommissioning from 1983-02-16; Decommissioned 1998-05-14 |
Operator: HEISSDAMPFREAKTOR-BETRIEBSGESELLSCHAFT MBH.
Owner: HEISSDAMPFREAKTOR-BETRIEBSGESELLSCHAFT MBH.
Source: IAEA Power Reactor Information System (PRIS), as of 2026-10-19.
Working Here
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 the U.S. State Department foreign per diem tables for FY 2026.
$237
Lodging/Night
$140
M&IE/Day
$377
Total/Day
Germany: rate for locations the State Department does not list separately
U.S. Department of State foreign per diem, for U.S. government and contractor travel.
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.
50.0551, 8.98527
Location & Contact
Physical address, phone number, and website for this facility. Use the directions link to get driving directions via Google Maps.
Plant Facts
About This Site
Written by NukeWorker from public records: facts that do not change. Operator, status and capacity come from the live data elsewhere on this page. Sources: Wikipedia: Gro%C3%9Fwelzheim Nuclear Power Plant.
The HDR Großwelzheim reactor was a prototype nuclear power reactor at Großwelzheim, in the municipality of Karlstein am Main, Bavaria, Germany.
Read more
It was a boiling water reactor designed to produce superheated steam (the name HDR stands for Heißdampfreaktor), rated at about 25 MW gross. Construction began in 1965. The reactor was first connected to the grid on 2 August 1970, but defects in the fuel elements prevented full-power operation. It was permanently shut down on 20 July 1971. The reactor building was later used for reactor safety experiments, and dismantling was completed in 1998.