| 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.
