The US Nuclear Regulatory Commission has decided not to accept Korea Hydro & Nuclear Power’s application for certification of its APR-1400 reactor design, as it contains insufficient information in some areas.

The decision does not reflect any NRC technical conclusion regarding the Korean reactor design, which is currently under construction at Shin Kori 3&4 in Korea and Barakah 1&2 in the UAE.

"While most of the application’s sections and chapters have enough information for the NRC to review, there are important exceptions," said Scott Burnell NRC public affairs officer.

Letter highlights APR-1400 application deficiencies
Application ‘deficiencies’ exist in the areas of instrumentation and control, human factors engineering, probabilistic risk assessment, and in the environmental report, NRC noted in a 19 December letter to KHNP. These were communicated to KHNP during a public meeting on 11-12 December 2013, NRC said.

In particular, NRC noted that the application "did not provide sufficient information are the software common cause failures of non-safety related control systems" nor on the critical characteristics of the safety I&C system platform.

It also lacked enough detail for some specific technical issues, including reactor coolant pump design, potential corrosion of some internal reactor parts, radioactive waste management and radiation protection.

The NRC staff also noted that KHNP has not yet submitted technical reports in four areas, including fuel seismic response evaluation and spent fuel criticality analysis.

The path forward for APR-1400 design review
KHNP submitted the design certification application to NRC in September 2013, following over three years of pre-application discussions with the regulator.

The NRC review of the APR-1400 design will remain at the pre-application stage, and pre-application meetings and discussions will continue, if KHNP wishes. Once the deficiencies have been addressed, the application may be resubmitted to the regulator for licensing in the USA.

The formal review will wait until the NRC is satisfied the application has enough information for its staff to create a "reasonable, reliable schedule and milestones for the certification process," Burnell said.

Photo: Cutaway of the APR-1400 reactor design (Source: KEPCO)