At the heart of the nuclear reactors’ shutdown and subsequent electricity shortage was a quality inspection company that neglected its role for the sake of its own interests.

Earlier in the week, the prosecution summoned the head of Saehan TEP for allegedly forging the quality certificate papers on substandard signal cables used in the recently suspended nuclear reactors.

A senior employee of JS Cable, too, was questioned on charges of supplying faulty parts and exerting pressure on Saehan TEP to certify them.

The recurrent incidents and irregularities detected over the past several years in the nuclear power sector are largely attributable to the monopolistic business structure and the symbiotic collusion among the related enterprises, critics say.

Since Saehan TEP signed a 300 million won ($269,000) contract with JS Cable years ago, the small company had effectively become heavily dependent on the cable supplier, finding it difficult to refuse its demands for favors.

Also, it turned out during the investigation that the company’s vice president is a former technology director of KEPCO Engineering & Construction, the organization in charge of approving the submitted quality certificates.

This relationship raised the suspicions that Saehan TEP, in turn, lobbied the state-run company to turn a blind eye to the faulty certificates.

Ironically enough, the firm earned an award from the former Ministry of Education, Science and Technology last year for outstanding performance.

While authorities are stepping up their probe into the triangular ties between JS Cable, Saehan TEP and KEPCO E&C, concerns are rising that this could be just the tip of the iceberg.

Woojin, another nuclear reactor component supplier, said on Tuesday that it would file a suit against Saehan TEP for fabricating cable quality certificates for years.

This raised the possibility that the ongoing construction of the Shin-Kori 3 Reactor, too, may be suspended or delayed as a considerable number of corresponding cables were supplied there.

To add to that, Rep. Woo Yoon-keun of the main opposition Democratic Party claimed on Wednesday that some 14 domestic and overseas nuclear reactors have been affiliated with Saehan TEP since 2010.

By Bae Hyun-jung (tellme@heraldcorp.com)