Protesters plan to hang a banner at a nuclear weapons production site in Oak Ridge early Friday afternoon that will declare the weapons illegal under a United Nations treaty.

The banner, which will say “Nuclear Weapons Are Illegal,” will be hung on a fence across from the main entrance to the Y-12 National Security Complex on Scarboro Road. The banner will be hung after parts of the international agreement—the Treaty on the Prohibition of Nuclear Weapons—are read, organizers said.

Protesters said they also plan to hang a poster of the text of the treaty and 122 yellow “X”s on the fence, one for every nation that voted in favor of the treaty at the United Nations.

“January 22, 2021, will be a historic day for nuclear weapons,” according to a press release from Oak Ridge Environmental Peace Alliance, which has organized weekly and annual events opposing nuclear weapons for many years. “On that day, at midnight, the Treaty on the Prohibition of Nuclear Weapons enters into force, establishing in international law a categorical ban on nuclear weapons, seventy-five years after their development and first use.”