In 1940 the common was adopted by the army for a new airbase called RAF Portreath. The airbase was put to a variety of uses during the second world war, which included being an RAF Fighter Command Station and a stopover for aircraft flying into Europe from the USA.
After the war, in 1950, a top secret plant was established on one of the former airfields in order to experiment with the large-scale production of chemical weapons. The site was chosen because, unlike other existing chemical development sites, Nancekuke was deemed far enough away from large centres of population to present a relatively low risk of contamination. It was also hoped that any gas leak would disperse out to sea! Fifteen tons of the nerve agent known as Sarin was produced at Nancekuke between 1953 and 1956, after which the plant ceased to operate, although large quantities of Sarin were stored there for many years to test its shelf life.
The plant closed down in 1976 and the buildings and equipment were docontaminated and buried in five dumps on the site, which included old mine shafts and quarries. The site was handed back to the RAF who continue to run it as a remote radar head known as RRH Portreath. After thirty years, when information about the activites at Nancekuke became public, there was controversy and unease among the local population about just how safe the plant and its disposal methods had actually been. In 2000 a local MP expressed concern about the potential effect of the buried chemicals on the natural environment and on the water supply and brought to public attention the testimonies of former workers, many of whom had died or reported bronchial and respiratory problems. An investigation by the Environment Agency was ordered and a remediation project launched in 2001.