Serious blunder

State utility should reflect on mishap, redouble safety steps

The abrupt abnormal heat output at the Hanbit 1 reactor last month was found to be due to human error, as initially thought. The state-run Korea Hydro & Nuclear Power (KHNP) changed the method of measuring control rods' capability for the first time in 14 years, and committed mistakes in calculating the reactor's heat output, the Nuclear Safety and Security Commission said Monday.

Worse yet, the KHNP employee who was in control of the rod had not been educated about the new method, the commission said in an interim report. We wonder whether the state utility run by taxpayer money has any excuses for such a sloppy operation.

At 3 a.m. on May 10, KHNP conducted a diagnostic test on the effectiveness of control rods at the Hanbit 1 reactor, whose heat output suddenly surged to 18 percent, far exceeding the upper limit of 5 percent set by the state utility. Instead of shutting down the reactor immediately, however, the nuclear power operator took this step half a day later, the regulatory body said. It would have been dangerous if the heat output had continued rising, even if the reactor fell short of exploding, according to experts.

In its initial investigation last month, the nuclear safety commission said a person without a proper license manipulated the control rods. The regulator said that a careful examination of the reactor and its fuel did not find any damage; but that comes as little comfort given the power generator's blunders in its operation.

The starting point of a nuclear power plant's safety awareness is trust. The incident at the Hanbit 1 reactor in Yeonggwang, some 300 kilometers southwest of Seoul, has shattered the public's confidence in the nation's nuclear power plants. Nuclear plants are an efficient source of energy if managed safely. Otherwise, however, few things could be more dangerous.

It was problematic enough that untrained or unqualified personnel were allowed to do jobs related directly to safety. Even more unforgivable was KHNP failed to stick to the basic manual after the safety accident occurred. The state utility should use the mishap as an occasion to make extraordinary efforts to rebuild public trust in the safety of nuclear power.