The is located in the city of Tsuruga, Fukui Prefecture, Japan. It is operated by the Japan Atomic Power Company (JAPC). The total site area is with 94% of it being green area that the company is working to preserve.JAPC Official Document (Japanese). Report of Electric Generating Plant Environmental Activities for 2010 .Page 20. The Tsuruga site is a dual site with the decommissioned prototype Fugen Nuclear Power Plant.
Construction of two new nuclear reactors is currently planned. However, there have been several delays due to the need for seismic upgrades, even before the March 2011 earthquake. As of 2014, construction has not begun on the two new reactors, although a tunnel has been completed linking the tip of the peninsula with the existing Units 1 and 2 sites.Tsuruga Power Station Units 3 and 4 Construction Plan Tsuruga 1 seeks life extension
Nuclear reactors on site Unit Type Commission date Output Tsuruga – 1 (decommissioning) BWR 14 March 1970 357 MWe Tsuruga – 2 PWR 17 February 1987 1160 MWe Tsuruga – 3 (planned) APWR – 1538 MWe Tsuruga – 4 (planned) APWR – 1538 MWe
The Tsuruga 1 reactor is the oldest commercial reactor in Japan. It was shut down for a safety inspection on 26 January 2011.Kyodo News, "Oldest reactor hits 42", Japan Times, 15 March 2012, p. 2. In March 2015 JAPC announced that Tsuruga 1 would be decommissioned. In March 2015 the Nuclear Regulation Authority (NRA) accepted an expert report that concluded the plant is on an active fault, which put any restart of Tsuruga 2 in doubt.
Events In March 1981, drainage from unit 1 caused a release of radioactivity. The forty-day cover-up of a spill of 16 tons of radioactive primary cooling water was revealed only in April.Brittle Power , p. 148. On 2 May 2011, Kyodo officials announced higher levels of radioactivity in the cooling water, JAPC admitted technical problems and announced to check for radioactivity on a daily basis from now on, instead of checking only every week, what has been standard procedure up to now.tageszeitung "taz" Im Kühlwasser des AKW Tsuruga II sind erhöhte radioaktive Werte gemessen worden (higher radioactivity measured in cooling water at nuclear power plant Tsuruga II), Retrieved 2 May 2011
On 12 November 2011 at 7:45 PM local time a fire broke out in the No. 1 reactor. After a switch for a spare electrical device at the water processing facility was operated by a worker, the fire was ignited because a short circuit caused a series of hot sparks. After the fire was put out, no casualties were reported. JAPC said that there was no leakage of radiation, because the reactor was closed for inspection.NHK-world (13 December 2011)Fire under control at Tsuruga nuclear plant JAIF (13 December 2011)Earthquake report 289
Juridical actions of citizens against restarting the nuclear reactors On 8 November 2011 a group of 40 citizens of Otsu in Shiga prefecture started a lawsuit at the Otsu District Court against Japan Atomic Power Company. They asked for a provisional court order to delay the restart of the two reactors at the Tsuruga Nuclear Power Plant in the city of Tsuruga. The plaintiffs argued that the plant is unsafe being built on a fault, and a severe accident could occur during an earthquake endangering the health of all residents, also contaminating Lake Biwa. They also criticize the government's safety and technological standards and regulations.
Seismic research done in 2005, 2011 and 2012 On 5 March 2012, a group of seismic researchers revealed the possibility of a 7.4M (or even more potent) earthquake under the Tsuruga Nuclear Powerplant. Before this date, the Japanese governmental Earthquake Research Committee and Japan Atomic Power had calculated that the Urasoko fault under the plant, combined with other faults connected to it, was around 25 km long. and could cause a 7.2M quake and a 1.7 meter displacement. On top of this, the presence of the oceanic faults were not taken into account by NISA and JAP in the assessment of the safety of the Tsuruga nuclear power plant.
Analysis of sonic survey and other data provided by Japan Atomic Power analysed by a panel of experts of Nuclear and Industrial Safety Agency showed the presence of multiple faults existing within 2 to 3 km from the Urasoko fault. According to Yuichi Sugiyama, a member of this group of scientists, these faults were highly likely to be activated together, and this would extend the length of the Urasoko fault to 35 km.
Computer-simulations calculating the length of a fault based on its displacement, showed the Urasoko fault to be 39 km long, a result close to the length estimated by the sonic survey data, and the fault could cause some 5 meter displacement when activated together with other faults.
Sugiyama, the leader of this research group of the National Institute of Advanced Industrial Science and Technology, warned that – as other faults on the south side of the Urasoko fault could become activated together – "The worst-case scenario should be taken into consideration".
According to the experts, there were many other faults located under one reactor on the west side of the Urasoku fault that could also move simultaneously. If this would be confirmed, the location of the Tsuruga nuclear plant would be disqualified.The Mainichi Shimbun (5 March 2012)Fault under Tsuruga nuclear plant could trigger M7.4 quake: research
On 6 March 2012, NISA asked Japan Atomic Power Co. to reassess the worst-case scenario for earthquakes at the Tsuruga-nuclear power plant: what damage this could do to the buildings on the site, because the Urazoko fault, running around 250 meters from the reactor buildings, could have a serious impact on the earthquake resistance of the power plant. NISA was also planning to send similar instructions to two other nuclear power plant operators in the Fukui area: Kansai Electric Power Company, and Japan Atomic Energy Agency, because the Mihama Nuclear Power Plant and the Monju fast-breeder reactor could also be affected by a possible earthquake caused by the Urazoko fault.The Mainichi Shimbun (7 March 2012) Quake severity estimate for Tsuruga nuclear plant to be reassessed
A few weeks later, on 21 March 2012, was revealed that the results of sonic research done in 2005 were ignored by JAPCO and that this data was kept secret in 2008 from a NISA research team of experts.The Mainichi Shimbun (22 March 2012)Japan Atomic Power overlooks data on fault beneath plant for 7 yrs
After an on-site survey at four points of geological layers by a panel of geologists, on 24 April 2012, NISA did admit that the 35-km-long Urazoko fault that runs under the Tsuruga reactors could be active. The experts determined that an earthquake did happen there some 4,500 years ago and that the other fault (without a name) running right beneath reactor 2 could slip and cause critical damage to the reactor induced by an earthquake caused by the Urazoko fault. By definition, a fault is "active" when it is believed to have caused a quake about 120,000 to 130,000 years ago or later. Japan Atomic Power was requested to produce a detailed assessment of the two faults under the reactors.The Japan Times (26 April 2012)Tsuruga plant may sit atop active fault Reactors' fate in limbo after NISA reverses safety assessment
On 14 November 2012, the Nuclear Regulation Authority (NRA) of Japan decided to conduct a field-survey on the Tsuruga-site to check the faults under and around the plant. On 1 December, and of necessary, 2 December, the investigative team led by NRA Commissioner and seismologist Kunihiko Shimazaki and four other experts planned to examine the site to exclude that faults running directly underneath the two reactors might move in conjunction with the active Urazoko fault located only 250 meters from the buildings.The Mainichi Shimbun (14 November 2012) Nuclear regulators set 2nd field survey destination at Tsuruga plant
The result of these investigations was presented at a meeting of experts on 10 December 2012. The conclusion was that the "fault zone of crushed rock called D-1, located beneath the plant's No. 2 reactor, could move in conjunction with the Urazoko fault." Kunihiko Shimazaki, the NRA-commissioner at the head of the team, told at the meeting, "that what appeared to be an extended section of D-1 had moved as an active fault in the past, together with the movement of the Urazoko fault". Although some local residents were stunned by the NRA-led team's judgment, the mayor of Tsuruga, Mayor Kazuharu Kawase, said that the outcome was "very tough", but that additional investigations could possibly confirm the safety of the plants.The Mainich Shimbun (10 December 2012)Restart of Tsuruga plant appears difficult due to possible active fault
In a draft-report presented 28 January 2013, a panel of experts of the Japanese NRA again affirmed that the D-1 fault that runs under reactor No. 2 is likely to be geologically active, because it could move in conjunction with the active Urazoko-fault located only some 250 meters from both the No. 1 and No. 2 reactor buildings. Although other outside experts will be asked to check the report "to improve" the contents, Kunihiko Shimazaki, NRA-member and panel head said : "We're not expecting to spend much time, but I can't tell at this moment by when (the review will finish)."The Mainichi Shimbun (29 January 2013)Panel says fault under Tsuruga plant likely active: draft report
On 22 January 2013, officials of Japan Atomic Power Co. received a version of the draft assessment report on the geologic faults running under the reactor complex. This was just a week before the report was scheduled to be made public by an NRA-appointed panel. Although the leaked information was not secret, for it contained a summary of public discussions, the incident was rather an embarrassment for the NRA because it undermined its policy of transparency and neutrality. Japan Atomic Power Co. was eager to get the information, because it wanted to prepare its counter arguments in the discussions. Although no money was paid for it, Tetsuo Nayuki, the NRA-official involved, was fired, because he violated the strict NRA regulations that, to ensure transparency, forbid single NRA staff members to meet officials of nuclear power plant operators. On 1 February, Nayuki was transferred to his former post at the Ministry of Education, Culture, Sports, Science and Technology.The Mainichi Shimbun (2 February 2013) Nuclear regulator sacked for leaking information to nuclear operator