ULSAN ― About 5,500 employees working in the Kori Nuclear Power Complex, stretching along the southern coastline in Ulsan and Busan, experienced a historic moment in their careers at 5 p.m. on Jan. 11 when the Shin-Kori reactor 2 was resumed following a seven-month hiatus.

“Now that Shin-Kori reactor 2 has restarted, I feel like I have finally come out of a long tunnel,” said Woo Jung-bon, head of the Kori Nuclear Power Complex, run by Korea Hydro & Nuclear Power, in a celebratory event.

KHNP is the nation’s sole nuclear power plant operator.

Over the past seven months, technicians at the Kori complex have worked to replace faulty parts and improve overall plant safety.

With the relaunch this month of the Shin-Kori reactor 2, the government’s nuclear operating body hopes to ease concerns over a possible wintertime power shortage.

Two other reactors ― Shin-Kori reactor 1 and Shin-Wolseong reactor 1 ― were also put back on track on Jan. 7.

The three reactors with 1,000-megawatt capacity each had been shut down last May after they were found to be using substandard control cables with fabricated quality certificates.

The discovery led the way for uncovering further deep-seated malpractices throughout the industry, including collusion between parts suppliers and KHNP. Various corruption scandals poured out at once, dealing a hard blow to the nuclear power industry.

The situation raised public fears about the safety of nuclear power, the biggest energy source in Korea, and triggered a shift in the nation’s nuclear power policy.

“KHNP will seek to be reborn as an organization with safety as the highest consideration in every aspect of its businesses to regain public trust in the organization and in nuclear power plants,’’ Cho Seok, CEO of KNHP, said in an event announcing the reactor’s resumption.

“For this, I will seek a field-driven management from this year, regularly visiting one of the 23 reactors nationwide and take the role of a troubleshooter on-site,” he said.

Before the nuclear power scandal, growth and export of made-in-Korea nuclear power technology were key topics in the industry.

Cho, a former vice energy minister, has also pushed an organizational reform drive internally since his appointment last September by bringing in talents from outside in an effort to break “pure-bloodism” in the firm, a root cause of serial scandals involving KHNP and its nuclear power plants.

“The company will make all-out efforts to mark 2014 as its first corruption-free year,’’ KHNP head said.

The shift in the nuclear power plant industry also has an impact on the Shin-Kori reactors 3 and 4, under construction in the same complex.

“We are considering plant safety and communication with neighbors above all to complete the projects as planned in 2015 and 2016, respectively,’’ Cho said.

The two advanced reactors, each boasting a 1,400-megawatt capacity, are the same model that Korea agreed to export to the United Arab Emirates in 2009.

By Seo Jee-yeon (jyseo@heraldcorp.com)