WICHITA, Kan. (AP) — A new report estimates that the Wolf Creek nuclear power plant could cost as much $1 billion to shut down when it reaches the end of its useful life about 30 years from now.

The Wichita Eagle reports that the cost is recalculated every three years. That allows the Kansas Corporation Commission to ensure enough money is collected from customers to fund a trust to pay for the future expense.

The report offers two options. Dismantling the plant as soon as it’s shut down would cost around $765 million in current-value dollars, although the cost could grow if spent nuclear fuel disposal issues aren’t resolved. Mothballing the plant near Burlington for several decades before beginning to tear it down would be safer but cost more than $1 billion.