Significant Incidents at Nuclear Power Plants and Nuclear Fuel Facilities in 2002
| Date | Operator/ Owner | Facility Name | Type | Short Description of Events |
| Jan. 30 | KEPCO | Takahama 4 | PWR | Damage to steam generator tube found during periodic inspection. |
| Mar. 4 | TEPCO | Kashiwazaki-Kariwa 1 | BWR | Reactor manually shut down due to coolant leak found caused by crack in shaft seal ring of recirculation pump motor |
| Mar. 7 | Tohoku-EPCO | Onagawa 2 | BWR | Coolant leak detected at condenser coolant flux measurement pipe during periodic inspection; 8cm crack found in welds of two measurement pipes. |
| Mar. 31 | JAPCO | Tokai II | BWR | Reactor automatically shut down due to transmission line stoppage caused by lightning; one of 185 control rods failed to insert into reactor core. |
| Apr. 2 | Hokuriku-EPCO | Shika 1 | BWR | Reactor manually shut down due to recirculation pump shaft oscillation during test operation. |
| Apr. 3 | JAPCO | Tokai II | BWR | Reactor manually shut down due to feedwater stopped during test operation; one control rod failed to insert into reactor core. |
| Apr. 18 | Shikoku-EPCO | Ikata 1 | PWR | Primary coolant pump shut down due to reactor containment sump water level increased alarm followed primary coolant pump shaft oscillation increased alarm during periodic inspection. |
| Apr. 21 | JNC | Fugen | ATR | Reactor manually shut down due to level of noble gasses storage equipment monitoring system and level of off-gasses chimney monitoring system during test operation; leak found at two special fuel assemblies. |
| Apr. 26 | TEPCO | Kashiwazaki-Kariwa 7 | BWR | Radioactive leak found at two fuel assemblies during periodic inspection. |
| May 5 | TEPCO | Kashiwazaki-Kariwa 3 | BWR | Reactor power manually reduced due to condenser vacuum rate lowered caused by turbine control equipment failed. |
| May 14 | TEPCO | Kashiwazaki-Kariwa 7 | BWR | Cracks found at reactor internal recirculation pump propeller during periodic inspection. |
| May 25 | Chubu-EPCO | Hamaoka 2 | BWR | Reactor manually shut down due to water leak from residual heat removal system low pressure injection pipe isolation valve drain piping weld during reactor start-up operation. |
| May 31 | Shikoku-EPCO | Ikata 3 | PWR | Leak found at heat exchange tube of feedwater heater during periodic inspection. |
| Jun. 4 | JNC | Tokai site | PFFF | Workers exposed to plutonium during glove exchange operation of glove box at plutonium fuel processing facility. |
| Jun. 20 | Tohoku-EPCO | Onagawa 2 | BWR | Reactor manually shut down due to increased water leak from recirculation pump mechanical seal. |
| Jun. 20 | Shikoku-EPCO | Ikata 2 | PWR | Containment vessel off-gasses monitoring system stopped due to filtration system being stuck. |
| Aug. 22 | TEPCO | Fukushima I-3 | BWR | Cracks found at control rod drive pressurized water system piping around contaiment vessel penetration area. |
| Aug. 23 | TEPCO | Kashiwazaki-Kariwa 3 | BWR | Cracks found at welds of core shroud on (made of SUS316L) lower region during periodic inspection; 360 degree crack found at outside surface of H6a position, and at inside surface of H7a position each. |
| Sep. 2 | TEPCO | Fukushima II-2 | BWR | Reactor manually shut down due to level of off-gasses radiation monitoring system increased. |
| Sep. 13 | JNFL | Rokkasho Repro. | Repro. | Mistake found at connection of piping in ventilation system. |
| Sep. 19 | Chubu-EPCO | Hamaoka 4 | BWR | Cracks found at welds of core shroud (made of SUS316L) lower region during periodic inspection; 360 degree crack found at outside surface of H6a position, and at inside surface of H7a position each. |
| Sep. 20 | Tohoku-EPCO | Onagawa 1 | BWR | Cracks found at welds of primary loop recirculation system piping(made of SUS316L) during periodic inspection. |
| Sep. 20 | Chubu-EPCO | Hamaoka 1/3 | BWR | Incident not available until Sep. 20, 2003; cracks found at welds of primary loop recirculation system piping (made of SUS316L) during former periodic inspection at Unit 1 and at Unit 3. |
| Sep. 20 | TEPCO | Kashiwazaki-Kariwa 1 | BWR | Cracks found at welds of primary loop recirculation system piping (made of SUS316L) during inspection outage. |
| Sep. 23 | Tohoku-EPCO | Onagawa 1 | BWR | Cracks found at welds of core shroud (made of SUS304L) middle and lower region during periodic inspection; cracks found at outside surface of H2 position and at outside surface of H6a position. |
| Sep. 30 | Hokkaido-EPCO | Tomari 1/2 | PWR | Significant wastage found at maintenance boiler tubes. |
| Sep. 30 | Tohoku-EPCO | Onagawa 1 | BWR | Wastage found at residual heat removal system welds during periodic inspection. |
| Oct. 3 | TEPCO | Fukushima II-2 | BWR | Cracks found at welds of core shroud (made of SUS316L) middle region during planned inspection; cracks found at inside surface of H3 position and at inside and outside surface of H4 position. |
| Oct. 5 | TEPCO | Kashiwazaki-Kariwa 1 | BWR | Cracks found at welds of core shroud (made of SUS316L) middle region during periodic inspection; cracks found at inside and outside surface of H3 position and at inside surface of H4 position. |
| Oct. 11 | TEPCO | Fukushima I-4 | BWR | Cracks found at control rod drive pressurized water system piping around contaiment vessel penetration area. |
| Oct. 13 | TEPCO | Fukushima I-4 | BWR | Cracks found at welds of core shroud (made of SUS316L) middle region during inspection outage; cracks found at inside surface of H4 position. |
| Oct. 21 | Tohoku-EPCO | Onagawa 1 | BWR | Cracks found at core spray nozzles during periodic inspection. |
| Oct. 23 | TEPCO | Fukushima II-3 | BWR | Cracks found at welds of core shroud (made of SUS316L) middle region during inspection outage; cracks found at inside surface of H3 position and at inside surface of H4 position. |
| Oct. 23 | JAPCO | Tokai II | BWR | recirculation flux control valve component lapsed and missed. |
| Oct. 24 | JNFL | Rokkasho Repro. | Repro. | Leaks and cracks found at spent fuel storage pool welds. |
| Oct. 30 | Chubu-EPCO | Hamaoka 4 | BWR | Cracks found at welds of primary loop recirculation system piping (made of SUS316L) during periodic inspection. |
| Oct. 31 | TEPCO | Fukushima II-4 | BWR | Cracks found at welds of core shroud (made of SUS316L) middle region during inspection outage; cracks found at inside surface of H3 position and at inside and outside surface of H4 position. |
| Nov. 15 | KEPCO | Mihama 1 | PWR | Reactor manually shut down due to primary coolant valve leak rate increased; cracks found at sea water drain pipes. |
| Nov. 25 | JNFL | Rokkasho Uranium Enrichment Plant | Enrich. | Homogenizing operation automatically stopped due to anti-overheat interlock system triggered by uranium hexafluoride cylinder temparature increased at RE-1 line homogeneous vessel. |
| Nov. 26 | TEPCO | Fukushima II-4 | BWR | Cracks found at welds of primary loop recirculation system piping (made of SUS316L) during inspection outage. |
| Dec. 3 | TEPCO | Kashiwazaki-Kariwa 2 | BWR | Cracks found at welds of primary loop recirculation system piping (made of SUS316L) during inspection outage. |
| Dec. 5 | TEPCO | Kashiwazaki-Kariwa 2 | BWR | Cracks found at welds of core shroud (made of SUS316L) top, middle and lower region during planned outage; cracks found at outside surface of H1 position and 360 degree crack found at outside surface of H6a position and at inside surface of H7a position. |
| Dec. 12 | JAPCO | Turuga 2 | PWR | Rector manually shut down due to fire at turbine building; pipe insulation substace fired. |
| Dec. 14 | Tohoku-EPCO | Onagawa 1 | BWR | Leak found at insturmentaion nozzle during periodic inspection. |
| Dec. 18 | TEPCO | Fukushima II-3 | BWR | Cracks found at welds of primary loop recirculation system piping (made of SUS316L) during inspection outage. |
| Dec. 26 | TEPCO | Fukushima II-2 | BWR | Cracks found at welds of primary loop recirculation system piping (made of SUS316L) during inspection outage. |
TEPCO: Tokyo Electric Power Co.
JNC: Japan Nuclear Cycle Developent Institute
KEPCO: Kansai Electric Power Co.
Tohoku-EPCO: Tohoku Electric Power Co.
JAPCO: Japan Atomic Power Co.
Hokuriku-EPCO: Hokuriku Electric Power Co.
JNFL: Japan Nuclear Fuel Limited
Shikoku-EPCO: Shikoku Electric Power Co.
Chubu-EPCO: Chubu Electric Power Co.
Hokkaido-EPCO: Hokkaido Electric Power Co.
ATR: Advanced Thermal Reactor
BWR: Boiling Water Reactor
PWR: Pressurized Water Reactor
PFFF: Plutonium Fuel Fabrication Facility
Repro.: Spent Fuel Reprocessing Plant
Enrich.: Uranium Enrichment Plant
