start was caused by the failure of the EDG air start system. Further investigation revealed that the utility did not exercise proper control of electrical distribution configuration to ensure the availability of the Station Auxiliary Transformer (SAT) while conducting test on the Unit Auxiliary Transformer (UAT). After restoring off-site power through the SAT, the operators eventually recovered shutdown cooling by restoring power to a residual heat removal pump. During the loss of shutdown cooling for 19 minutes, the reactor coolant maximum temperature in the hot leg increased from 37℃ to 58.3℃ (approximately 21.3℃ rise), and the spent fuel pool temperature slightly increased from 21℃ to 21.5℃. There was no adverse effect on the plant safety as a result of this event, no radiation exposure to the workers, and no release of radioactive materials to the environment. However, inconsistent with the requirements, the licensee did not report the SBO event to the regulatory body in a timely manner and did not declare the "alert" status of the event in accordance with the plant emergency plan. The licensee reported this event to the regulatory body about a month after the event had occurred. On 2 October 2012 at 8:10 a.m., Shin Kori-1 was shut down after a warning signal indicated a malfunction in the control rod system which triggered an investigation to verify the exact cause of the problem. In June 2013, Kori-2 was shutdown, and Kori-1 ordered to remain offline, until safety-related control cabling with forged safety certificates is replaced. Control cabling installed in the APR-1400s under construction failed flame and other tests, so need to be replaced delaying construction by up to a year. In October 2013, cable installed in Shin Kori-3 failed safety tests, including flame tests. Replacement with U.S. manufactured cable delayed the startup of the plant, which eventually entered commercial operation 3 years late. See also Nuclear power in South Korea List of nuclear reactors in South Korea References External links Kori plant overview Nuclear power stations in South Korea Nuclear power stations with reactors under construction 1978 establishments in South Korea Energy infrastructure completed in 1978