{"id":"1984868c-32cd-4a72-b4e0-0db6b5c4b4bd","slug":"tepco-fukushima-daiichi-nuclear-disaster-2011","kind":"other","headline":"Fukushima Daiichi nuclear disaster: three reactor meltdowns trigger 40-year robotic decommissioning program","summary":"On March 11, 2011, a magnitude 9.0 earthquake and 15-meter tsunami struck the Fukushima Daiichi Nuclear Power Station, destroying diesel generators that powered coolant pumps. Three reactors suffered full meltdowns and hydrogen explosions, releasing radioactive contamination. Three TEPCO employees were killed by the tsunami. The disaster initiated a decades-long decommissioning program relying on robotic systems for fuel debris retrieval, radiation surveying, and site inspection.","occurredAt":"2011-03-11T14:46:00.000Z","reviewStatus":"unreviewed","modelId":null,"deploymentId":null,"companyId":"1a18c6df-ef58-4a1d-9ae0-11fbc237fc68","dataCenterId":null,"aliases":[],"collisionRisk":"none","reviewNote":null,"severity":"catastrophic","rootCauseCategory":"other","rootCauseDetail":"Magnitude 9.0 earthquake and 15-meter tsunami disabled emergency diesel generators, causing total loss of cooling at Units 1-3.","affectedUnitsCount":null,"affectedUnitsBasis":null,"remediationStatus":"in_progress","regulatoryAction":"other","regulatoryBody":"NRA (Japan Nuclear Regulation Authority)","propertyDamageEstimateUsd":null,"damageEstimateBasis":null,"bodilyInjurySeverity":null,"fatalityCount":null,"lossCostClass":null,"sourceQualityTier":null,"oshaRecordable":null,"oshaCaseNumber":null,"rootCauseDisclosed":null,"publicDisclosureDate":null,"insuranceClaimPublic":null,"formFactor":null,"latitude":null,"longitude":null,"autonomyClass":null,"legalOutcomeClass":"unknown","createdAt":"2026-08-31T15:06:22.485Z","updatedAt":"2026-08-31T15:06:22.485Z","model":null,"deployment":null,"company":{"id":"1a18c6df-ef58-4a1d-9ae0-11fbc237fc68","name":"TEPCO","slug":"tepco","description":"Tokyo Electric Power Company Holdings (TEPCO) is Japan's largest electric utility and the operator of the Fukushima Daiichi Nuclear Power Station, where it pioneers robotic decommissioning using remotely operated and [Spot](/models/boston-dynamics-spot) quadruped robots from [Boston Dynamics](/companies/boston-dynamics). Since the 2011 disaster, TEPCO has deployed over 16 types of robots for fuel debris retrieval, radiation surveying, and facility inspection — including the Telesco telescopic device that extracted the first sample of melted fuel in 2024. Its subsidiary TEPCO Power Grid became the first Japanese power company to introduce an arm-equipped quadruped robot for underground substation inspections in 2025.","status":"private","founded":1951,"hq":"Tokyo, Japan","hqLat":35.6768601,"hqLng":139.7638947,"hqGeocodedAt":"2026-08-23T21:09:15.750Z","hqAddress":null,"hqPrecision":null,"website":"https://www.tepco.co.jp/en/","fundingTotal":null,"type":"hardware","roles":[],"reviewStatus":"reviewed","heatIndex":52,"lifecycleState":"active","supersededByCompanyId":null,"sources":[{"url":"https://www.tepco.co.jp","title":"TEPCO — Tokyo Electric Power","sourceName":"TEPCO (official)"},{"url":"https://asia.nikkei.com/business/energy/japan-s-tepco-to-counter-capacity-squatters-in-ai-data-center-boom","title":"Japan's TEPCO to counter 'capacity squatters' in AI data center boom","sourceName":"Nikkei Asia","publishedAt":"2026-10-03"}],"keyFacts":[{"label":"Headquarters","value":"Tokyo, Japan"},{"label":"Status","value":"private"},{"label":"Type","value":"hardware"},{"label":"Rules vs AI DC 'capacity squatting' / reserved unused power (reported, Oct 2026)","value":"Reported ([reported](https://asia.nikkei.com/business/energy/japan-s-tepco-to-counter-capacity-squatters-in-ai-data-center-boom)): Nikkei Asia (Oct 3 2026) says Tokyo Electric Power Co. Holdings is among Japanese utilities tightening electricity rules for data centers to counter \"capacity squatting\" (reserving power capacity that ends up underutilized). Theme: AI DC projects reserving grid capacity without immediate use. Cap: Nikkei Asia reporting; not a TEPCO English press release fetched this pass."}],"aliases":[],"collisionRisk":"low","reviewNote":null,"atsProvider":null,"atsSlug":null,"factoryLocations":null,"manufacturingCapacity":null,"orgType":null,"burnSignal":null,"litigationEvents":null,"insurancePostureDisclosed":null,"unitEconomicsDisclosed":null,"tickerSymbol":"9501.T","stockExchange":"Tokyo Stock Exchange","secCik":null,"revenueUsd":null,"revenueBasis":null,"revenueAsOf":null,"employeeCount":null,"employeeCountBasis":null,"employeeCountAsOf":null,"marketCapUsd":null,"marketCapAsOf":null,"marketCapSource":null,"createdAt":"2026-08-09T05:08:50.338Z","updatedAt":"2026-10-03T15:58:48.339Z"},"derived":{"status":"active"},"sources":[{"id":"f1e493f7-49ff-4aa8-8b2d-ef726b48fc01","incidentId":"1984868c-32cd-4a72-b4e0-0db6b5c4b4bd","url":"https://world-nuclear.org/information-library/safety-and-security/safety-of-plants/fukushima-daiichi-accident","label":"World Nuclear Association","publishedAt":"2024-01-01T00:00:00.000Z","notes":null,"title":null,"sourceName":"World Nuclear Association","mediaType":"article","videoId":null,"channel":null,"durationSec":null,"timestampSec":null,"createdAt":"2026-08-31T15:06:22.485Z","updatedAt":"2026-08-31T15:06:22.485Z"},{"id":"fcf9fa6b-a3ba-4a40-bded-ace212b0951b","incidentId":"1984868c-32cd-4a72-b4e0-0db6b5c4b4bd","url":"https://en.wikipedia.org/wiki/Fukushima_nuclear_accident","label":"Wikipedia","publishedAt":"2024-01-01T00:00:00.000Z","notes":null,"title":null,"sourceName":"Wikipedia","mediaType":"article","videoId":null,"channel":null,"durationSec":null,"timestampSec":null,"createdAt":"2026-08-31T15:06:22.485Z","updatedAt":"2026-08-31T15:06:22.485Z"},{"id":"79624876-c74d-40ab-bfab-bf4800478a57","incidentId":"1984868c-32cd-4a72-b4e0-0db6b5c4b4bd","url":"https://www.iaea.org/topics/response/fukushima-daiichi-nuclear-accident","label":"IAEA","publishedAt":"2024-01-01T00:00:00.000Z","notes":null,"title":null,"sourceName":"IAEA","mediaType":"article","videoId":null,"channel":null,"durationSec":null,"timestampSec":null,"createdAt":"2026-08-31T15:06:22.485Z","updatedAt":"2026-08-31T15:06:22.485Z"}],"responses":[],"statusEvents":[],"jsonLd":{"@context":"https://schema.org","@type":"NewsArticle","@id":"https://registry.deploy.report/incidents/tepco-fukushima-daiichi-nuclear-disaster-2011","url":"https://registry.deploy.report/incidents/tepco-fukushima-daiichi-nuclear-disaster-2011","headline":"Fukushima Daiichi nuclear disaster: three reactor meltdowns trigger 40-year robotic decommissioning program","description":"On March 11, 2011, a magnitude 9.0 earthquake and 15-meter tsunami struck the Fukushima Daiichi Nuclear Power Station, destroying diesel generators that powered coolant pumps. Three reactors suffered full meltdowns and hydrogen explosions, releasing radioactive contamination. Three TEPCO employees were killed by the tsunami. The disaster initiated a decades-long decommissioning program relying on robotic systems for fuel debris retrieval, radiation surveying, and site inspection.","identifier":"1984868c-32cd-4a72-b4e0-0db6b5c4b4bd","datePublished":"2011-03-11T14:46:00.000Z","articleSection":"other","publisher":{"@id":"https://deploy.report/#organization"},"author":{"@id":"https://deploy.report/#organization"}},"framework_metadata":{"framework_schema_version":"0.1.0","verification_status":"unreviewed","maturity_stage":null,"lifecycle_state":null,"architectural_position":{"cohort":null,"sub_cohorts":[]},"within_cohort_verified_vs_claimed_pair":null,"cap_flags":[],"verification_depth":{"sources_count":3,"primary_source_types":["knowledge-base"]}}}