Illinois Attorney General Lisa Madigan announced Wednesday that the Will County Circuit Court has approved the preliminary injunction. Among the court orders is that Exelon implement more effective programs for detecting leaks.
The plant has leaked tainted water dating back to 1996, but Exelon says the tritium levels don't pose a health threat.
The U.S. Environmental Protection Agency says exposure to tritium can increase the risk of developing cancer.
Madigan says the injunction offers an initial blueprint for addressing the contamination, but she says other legal action against the company will continue.