Pashenko found a spike of radon gas when he tested a PORTS sample over time. Buske reported that radium, not uranium, would be the source of radon of that quantity. Radium can be used as a powerful source of neutrons. Buske, an expert on nuclear weapons facilities and the politics surrounding the production of nuclear weapons, concluded that a probable explanation for radium in the sample is that the US is engaging in micronuclear neutron weapons research. If this is proven to be true, it would be a violation of the Nuclear Proliferation Treaty to which the U.S. is signatory.