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 2026-09-12 06:10:18 UTC
Current external hazard exposure
LOW · 0.7/100
Earthquake 288 km from Onagawa Nuclear Power Plant, 5 d ago (severity 18%, distance factor 0.15, recency 0.28) → exposure LOW (0.7/100).
Baseline: this exposure is at or above 1% of the 634 observations recorded for this facility since 2026-06-14 · highest recorded 23.5/100.
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 M4.9 | USGS | 2026-09-06 05:15 | 288 km |
Recent exposure history
- 2026-09-11 17:01 · LOW 0.7
- 2026-09-11 04:01 · LOW 0.8
- 2026-09-10 06:01 · LOW 1.0
- 2026-09-09 11:05 · LOW 1.2
- 2026-09-08 20:01 · LOW 1.4
- 2026-09-08 13:01 · LOW 1.5
- 2026-09-08 01:01 · LOW 1.7
- 2026-09-07 13:01 · LOW 1.9
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