JPDR
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 permanent shutdown.
| Unit | Type | Model | Net MWe | Construction | Grid | Commercial Op | Shutdown | Status |
|---|---|---|---|---|---|---|---|---|
| JPDR | BWR | BWR-1 | 12 | 1960-12-01 | 1963-10-26 | 1965-03-15 | 1976-03-18 | Permanent Shutdown |
Capacity, milestones and suppliers
| Unit | Design MWe | Gross MWe | Thermal MWt | First Criticality | Reactor Supplier | Turbine Supplier | Notes |
|---|---|---|---|---|---|---|---|
| JPDR | 10 | 13 | 90 | 1963-08-22 | GENERAL ELECTRIC CO. | GENERAL ELECTRIC CO. / TOSHIBA CORPORATION |
Lifetime performance, through 2025
| Unit | Electricity Supplied | Load Factor | Energy Availability | Operating Factor |
|---|---|---|---|---|
| JPDR | 0.0 TWh | 4.6% | 0.4% | 7.0% |
Operator: JAPAN ATOMIC ENERGY AGENCY
Owner: JAPAN ATOMIC ENERGY AGENCY
Source: IAEA Power Reactor Information System (PRIS), as of 2026-10-14.
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.
$208
Lodging/Night
$107
M&IE/Day
$315
Total/Day
Japan: 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.
Photos
Photos of this facility from the NukeWorker photo gallery. Click the header or any photo to browse the full album.
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.
36.4585, 140.606
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: WNA: Japan Power Demonstration Reactor (JPDR); JAEA: JPDR dismantling.
The Japan Power Demonstration Reactor (JPDR) was a small boiling water reactor of about 12 MW electrical output at Tokai, Ibaraki Prefecture, Japan, run as a research project of the Japan Atomic Energy Research Institute.
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It reached first criticality on 22 August 1963 and was connected to the grid on 26 October 1963, the date later commemorated in Japan as Atomic Energy Day. It entered commercial operation in March 1965 and was permanently shut down on 18 March 1976. It was then used as a demonstration project for reactor dismantling, which began in the early 1980s and was completed in March 1996 without accidents.