[4] Tests to determine building damage by nuclear blasts have left remains at the site that are of historical interest.
A carbonate aquifer makes Area 5 not well suited to underground testing, so there were fewer detonations carried out.
[5] The Nonproliferation Test and Evaluation Complex (NPTEC), formerly called the Hazardous Material (HAZMAT) Spill Center, is located on Frenchman Flat in Area 5, a natural geological basin.
It provides a secure test-bed, calibrated release systems, weather data, ground truth instrumentation, and logistics in field verification and validation of technology.
Hazardous residues from these tests continue to provide a realistic environment for safety training, radiological monitoring, sampling instruction and first-responder drills.