Nuclear regulators concluded Wednesday that Japan Nuclear Fuel Ltd. violated legally binding safety rules by failing to conduct necessary checks for over a decade at its uncompleted spent nuclear fuel reprocessing plant in the country’s northeast.

The failure of checks at an underground portion of the plant in the village of Rokkasho in Aomori Prefecture for about 14 years eventually resulted in about 800 liters of rainwater flowing into a building housing an emergency diesel generator in August this year. The generator is a crucial device in times of crisis such as the loss of external power.

Japan Nuclear Fuel President Kenji Kudo said at a Nuclear Regulation Authority’s meeting that he will prioritize inspections of all facilities at the plant and suspend its operations to seek a safety approval on the plant to put it on stream.

The utility plans to check its facilities and some 600,000 devices by the end of this year before requesting the authority to resume its safety assessment for the plant.

The body applied for a safety assessment of the plant in 2014 and aimed to complete it in the first half of fiscal 2018, but the goal is likely to be delayed due to the need for inspections.

The envisioned nuclear fuel reprocessing plant is a key component of the government’s nuclear fuel recycle policy, which aims to reprocess spent uranium and reuse extracted plutonium and uranium as reactor fuel.

But the Rokkasho plant has been inundated with problems, with its completion date postponed 23 times since 1997, its initial target. It also had to meet new, tougher safety standards made in the wake of the crisis at the Fukushima No. 1 nuclear power complex, triggered by the powerful March 2011 earthquake and tsunami that devastated parts of the Tohoku region.

The authority also said holes and cracks at exhaust pipes found at Japan Nuclear Fuel’s uranium enrichment plant in September also violated safety rules. The defects had been undetected due to a lack of inspections.

A utility compiles safety programs, which need to be assessed and approved by the authority.

If any grave flaws are found, the authority can issue an order to stop the operation of the plants or retract its approval to construct a nuclear plant.

Japan Nuclear Fuel “should have a substantial sense of crisis,” a member of the authority said. “We will take necessary measures if an improvement is not seen in ensuring the safety (in operating the plant).”