Neste Corp. will undertake a major turnaround beginning in August at its 10-million tonne/year (tpy) refinery in the Kilpilahti industrial area of Porvoo, Finland, about 20 miles east of Helsinki.

Budgeted at an overall investment of more than €400-million ($457 million) and scheduled to run through October, the 9-week turnaround will involve a full shutdown of the refinery to execute works that include routine maintenance, unspecified asset improvement initiatives, and statutory inspections aimed at ensuring the Porvoo site’s ongoing safety, availability, and competitiveness, the operator said on June 30.

Alongside Neste’s own workforce of about 1,000 employees, the maintenance event will also involve about 6,500 additional specialized experts from more than 100 different contractor companies—80% of which are Finnish—from Germany, Poland, Spain, Sweden, the Netherlands, and the UK, according to Jim Holmbäck, Neste’s director of turnarounds.

To ensure security of supply, Neste confirmed it will produce and store enough products ahead of taking the refinery offline for the planned maintenance event to ensure uninterrupted customer deliveries during the shutdown period.

The Kilpilahti port and the Porvoo distribution terminal will operate normally throughout the turnaround, the company said.

Further details regarding the major routine maintenance event—which occurs every 2.5-3 years—have yet to be revealed.