Press Releases 2013

At around 2:27 PM on April 5, an alarm indicating a power board failure related to power supply went off and Unit 3 spent fuel pool alternative cooling system was confirmed to be suspended. As a result of investigating the condition of the alternative cooling system at the site, no abnormality such as leakage was found.

The cause of the incident is assumed to be a ground fault which may have occurred during the implementation of countermeasure against small animals (installation of entry prevention net) on the power board of concern. The incident will be investigated in details.

Since no problem was found as a result of insulation resistance test performed on the power supply facilities affected by the incident from 3:50 PM to 4:00 PM, the cooling system was restarted at 5:20 PM.

No problem has been found with the system operation after restart.

*The water temperature of Unit 3 spent fuel pool as of 2:00 PM today (April 5) was 15.1℃ and the amount of time to reach the maximum allowed limit stipulated by the technical specification (65℃) is estimated to be approx. 2 weeks.