The Kashiwazaki-Kariwa Plant

John Morrissey
February 23, 2015

Submitted as coursework for PH241, Stanford University, Winter 2015


Fig. 1: Coastal view of the KK plant. (Source: Wikimedia Commons)

The Kashiwazaki-Kariwa Power Plant (KK power plant) is located on the shores of the sea of Japan, in the Niigata prefecture as shown in Fig. 1. The plant is the largest nuclear power plant in the world and with seven reactors its total output is 8212 MW. [1] However since its construction in mid 1980, there have been several incidents that have caused the plant to be temporarily out of commission. In fact the power plant is still not running today. [2]

Natural Disasters

So what events led to these incapacitations? The main answer is natural disasters. The plant was built extremely close to a large and active fault line, which has caused the plant unending troubles in the forms of earthquakes and tsunami's. The devastating proximity of this fault line can be seen in Fig. 2, which shows the seismic center of the 2007 Chuetsu offshore earthquake, the first of these unpredictable disasters, and its distance to the KK plant.

This earthquake measured a 6.6 on the seismic scale, and its epicenter was a mere kilometers from the plant itself. [3] Although the damage to the reactors themselves was not extensive, this occurrence prompted a deeper look into the safety measures in place at the plant - an insight that cost the plants owners, TEPCO, almost two years of business. Furthermore, following on the heels of a smaller quake in 2004, this disaster led to the belief that the plant could have been closer to the fault line than anticipated.

Fig. 2: Known fault lines and position of the Chuetsu Earthquake epicenter relative to KK plant. (Source: Wikimedia Commons)

The 2011 earthquake and tsunami that destroyed much of east and Southeast Asia, confirmed this worry. Although this earthquake was not fatal in its destruction of the plant, it was arguably the worst atomic crisis since Chernobyl and has caused all units to be shut down and undergo safety improvements. The restarting of the plant is projected to be in late 2015.

Problems and the Path to Recovery

Obviously, the KK plant runs on many dangerous and radioactive materials and thus when these sizable tremors occur, problems arrive. Radioactive and spent materials leaked into the sea of Japan and hundreds of drums containing unsafe substances, were tipped over by the vibrations too - these materials included radioactive water, Co-60, Iodine, Cr-51. [4] Fortunately neither of these occurrences caused fatalities due to nuclear waste, but the risk is there. It has taken TEPCO and the employees of the KK plant years, but through detailed research on how common and sizable tsunamis and earthquakes are in the area as well as substantial renovations, for health and safety, the plant seems almost ready to come back into action, more stable and safe than ever, it will be a relief for TEPCO and Japan to have the world largest power plant back running.


Although the KK plant seems to be particularly disadvantaged with its location being so close to a fault line, the length and number of times that it has been shut down demonstrate the fragility of nuclear power plants. Furthermore, although the nuclear waste emitted at the KK plant was of a negligible amount, the reaction to its spillage was proportional to how harmful this waste could be. The potentially traumatic outcomes of an accident at such a plant, become even more possible and less foreseeable when for-profit companies begin to falsify their data - a scandal that caused the KK plant to be shut down in 2002. [5] These plants are undeniably important sources of energy for the future, however the fragility of their nature combined with their terrifying potential mean that they must be monitored and regulated extremely closely, much more than they currently are or have been in the past.

© John Morrissey. The author grants permission to copy, distribute and display this work in unaltered form, with attribution to the author, for noncommercial purposes only. All other rights, including commercial rights, are reserved to the author.


[1] J. Kernaghan and R. Kassawara, "EPRI Independent Peer Review of the TEPCO Seismic Walkdown and Evaluation of the Kashiwazaki-Kariaw Nuclear Power Plants", Electric Power Research Institute, January 2008.

[2] K. Hamada, Restart of Japan's Largest Nuclear Plant Still in Doubt, Reuters, 6 Jan 15.

[3] H. Miyake et al. "Source Fault of the 2007 Chuetsu-oki, Japan, Earthquake," B. Seismol. Soc. Am. 100, 384 (2010).

[4] A. Makoto et al., "Concerns of Disaster Medical Assistance Team (DMAT) Members About Troubles at the Nuclear Power Plant: Experience From The Nigata Chuetsu-Oki Earthquake, 16 July 2007, in Japan," Health Phys. 98, 804 (2010).

[5] Q. Wang, X. Chen, X. Yi-chong, "Accident like the Fukushima Unlikely in a Country with Effective Nuclear Regulation: Literature Review and Proposed Guidelines, Renew. Sustain. Energy Rev. 17, 126 (2013).