NATCHEZ — Passers-by who see a nuclear decontamination station at Natchez High School this weekend need not worry — it’s just a drill.

In fact, it’s not even a drill. It’s practice for a drill next year.

This week Natchez Fire Department and Adams County volunteer firefighters will take their annual refresher course for what to do if there is an incident at the Grand Gulf Nuclear Generating Station near Port Gibson.

Over the next few days, the Mississippi Emergency Management Agency will give firefighters classroom sessions to remind them of how to use equipment and to introduce them to any new equipment, NFD Training Officer Luis Videgaray said.

The refresher will culminate in a hands-on session Friday and Saturday at Natchez High School during which firefighters will practice decontamination processes for those who might have been tainted with nuclear material, Videgaray said.

Adams County is one of the host counties for evacuees if an incident occurs at Grand Gulf, County Emergency Management Director Robert Bradford said, and all of those who come in will have to go through a decontamination process.

“At the practice, you will receive them, place them in the staging area, evaluate if they are contaminated and separate them and decontaminate them,” Bradford said.

“If you are contaminated, you go through the steps of being washed with decontamination kits. The objective is to keep the contaminants in one area so you won’t spread them throughout the city.”

While this year’s exercise is just practice, next year will be considered a full drill, and will include response to a scenario in which a hostile person or entity has created a nuclear incident at the plant.

“We do this so we can continue to train and make it repetitious so we can stay on task,” Bradford said.

Grand Gulf Nuclear Station is the only nuclear power plant to produce electricity in Mississippi. It opened in 1985, and was upgraded  in 2012. It is the largest single-unit nuclear power plant in the U.S., and the fifth largest in the world.