Our reactors need an overhaul

Authorities discovered that a malfunction in the backup diesel-powered generator was the key reason behind the 12-minute blackout at the country’s oldest nuclear reactor last month. The Nuclear Safety and Security Commission probing the case said that the diesel generator did not work properly due to a malfunctioning pressure valve. The Gori-1 reactor in Busan was active for nine days without any support from the power generator. It could have triggered a major disruption and possibly a meltdown if the other backup electricity system did not supply power.

The Gori-1 unit has two diesel generators. One is turned off during maintenance checks. The other one, which was the cause of the recent accident, tested normal during a check-up on Feb. 16-23 even though it malfunctioned on Feb. 9. It is hard to believe that a generator that stopped earlier last month worked normally during a check-up weeks later and then broke down again several weeks later. We can only suspect attempts from the operator and supervisors to cover up their mistakes and negligence.

Korea Hydro & Nuclear Power, which operates the country’s nuclear reactors, extended the life span of the oldest power grid for another decade by replacing most of its outdated parts in 2007. But it kept the 34-year-old diesel generators, saying they still worked fine. Placing cost over safety concerns may have led to the problem in the backup power system. The state agency assured that it has multiple backup generators that can be switched to manual operation to brush aside concerns for any Fukushima-like disasters. But the emergency backup systems were of no use during the power failure at the Busan facility.

The authorities have faulty logic in arguing against public complaint and suspicion over safety in commercial nuclear facilities. Nuclear power reactors have been considered among the country’s top security facilities and sealed off to public scrutiny. But recent accidents underscore slack maintenance, loose oversight in examinations and bureaucratic corruption in reactor operation. Even the workers at the Gori reactor raised concerns over the outdated facilities. The public can no longer trust authorities’ assurances of nuclear safety.

We need to thoroughly examine our reactor facilities. The insiders cannot be entirely trusted. Neutral, outside experts must be employed to check backup generators at 42 power grids across the nation. Law enforcement agencies should also join a government-led investigation. If there are any problems, they must be rooted out immediately.