Nuclear Risk Watch · Facility Report
Onagawa Nuclear Power Plant
Japan · Tohoku Electric Power · nuclear power plant · operational · 2,174 MW installed
38.401, 141.500 · generated 2026-11-12 20:24:24 UTC
Current external hazard exposure
LOW · 6.9/100
Earthquake 38 km from Onagawa Nuclear Power Plant, 4 d ago (severity 10%, distance factor 0.78, recency 0.40) plus 7 other active hazards → exposure LOW (6.9/100).
Baseline: this exposure is at or above 73% of the 382 observations recorded for this facility since 2026-08-14 · highest recorded 13.0/100.
Facility impact: no operational effect has been confirmed in the public sources reviewed.Exposure measures external hazard conditions near the site; it is not an assessment of plant engineering safety.
Nearby active hazards (in range)
| Type | Source | When (UTC) | Distance |
|---|---|---|---|
| EARTHQUAKE M4.5 | USGS | 2026-11-08 20:16 | 38 km |
| EARTHQUAKE M4.6 | USGS | 2026-11-09 05:01 | 212 km |
| EARTHQUAKE M4.9 | USGS | 2026-11-10 05:20 | 230 km |
| EARTHQUAKE M4.7 | USGS | 2026-11-08 09:23 | 239 km |
| EARTHQUAKE M5.7 | USGS | 2026-11-09 04:52 | 241 km |
| EARTHQUAKE M5.5 | USGS | 2026-11-07 11:07 | 246 km |
| EARTHQUAKE M4.6 | USGS | 2026-11-11 03:56 | 258 km |
| EARTHQUAKE M4.8 | USGS | 2026-11-12 04:07 | 283 km |
Recent exposure history
- 2026-11-12 19:04 · LOW 6.9
- 2026-11-12 16:03 · LOW 7.6
- 2026-11-12 14:03 · LOW 7.8
- 2026-11-12 11:03 · LOW 8.0
- 2026-11-12 09:04 · LOW 8.2
- 2026-11-12 07:03 · LOW 8.3
- 2026-11-12 05:02 · LOW 8.5
- 2026-11-12 02:02 · LOW 8.0
How this score is calculated
External hazard exposure (0–100) combines four factors: hazard type, severity, proximity to the site and recency — higher when a serious hazard is close and recent. It does not incorporate facility vulnerability or consequence. Full methodology.
LOW 0–20MODERATE 20–40ELEVATED 40–60HIGH 60–80SEVERE 80–100