Routine mapping of the reactor core has confirmed that all 193 nuclear fuel assemblies at unit 1 of Exelon’s Braidwood Nuclear Generating Station are correctly aligned.

The core mapping was completed in 53 minutes during a recent refueling outage at the plant. It was carried out using Newton Labs’ NM200E tool, which consists of a radiation-resistant camera head and a control console running software developed by Newton.

"The software enables the precise and consistent global mapping of fuel assembly S-hole positions, including any degree of misalignment or nozzle rotation. This is in contrast to the less accurate nozzle gap measurements by video micrometer," Newton Labs said.

It added that the NM200E tool has been adopted by Exelon as their ‘primary method’ for determining nozzle position in pressurized water reactors,

Over the last three years, the same Exelon and Newton outage team has deployed the NM200E system during three previous outages at the Braidwood plant and twice at the Byron Nuclear Generating Station. The system is also shared by Three Mile Island.

The systems’ camera heads, manufactured by Newton Labs in 2010, have each been deployed multiple times in high radiation environments and have not required adjustment or refurbishment.