The Department of Energy’s National Nuclear Security Administration will conduct low-altitude helicopter flights over Wellesley and the rest of the Boston Marathon route over the next few days to measure naturally occurring background radiation. This gives authorities a baseline to use in their security and emergency preparedness efforts.
You might get a glimpse of a twin-engine Bell 412 helicopter, which is operated by the Remote Sensing Laboratory Aerial Measuring System from Joint Base Andrews and is equipped with radiation sensing technology. It will fly during the day.
The administration has conducted such flights in support of the Boston Marathon since 2014.