The maps below were developed subsequent to a Cape Downwinders meeting with the Massachusetts Department of Public Health on September 12, 2014.The maps describe the monitoring capabilities of the current (2014) airborne radiological monitoring system at and around Pilgrim Nuclear Power Station. In addition, meteorological monitoring is provided by a centrally located meteorological tower.
The monitoring stations marked as green triangles only monitor radiation (gamma). The blue and yellow triangles identify the locations of remote off site stations that monitor (gamma) radiation as well as wind speed and direction. The area to the Cape Cod Bay side of the plant has no monitoring stations, so any radiation that drifts or is blown in that direction goes without notice or measurement by any of the monitors.
MDPH map with overlay of detection vectors
Albeit a crude first analysis, transferring the boundaries of the blind spot to a larger map and projecting those lines to Cape Cod reveals that a portion of the Cape, from Brewster & Chatham out to P-Town, lie in the arc of the blind spot. Obviously a more complete monitoring system would come in handy for Cape Codders during an emergency. Not to mention the benefit of having 360 degrees of documented coverage around the the plant on a 24/7 basis, as is the standard operating procedure in the landward directions.
Over the years any radiation releases that have occurred during periods when the wind direction has been towards the arc of the blind spot, the same direction as the prevailing winds, have gone unnoticed Similarly, an emergency radiation release that drifts or gets blown in the blind spot direction will not be monitored.
Expanded map with overlay of detection vectors