The previous post "Half Life Calculated" dated 23 Nov 2017 suggests that temperature effects radioactivity and is maximized at one specific temperature, \( T_{v\,p}\). This temperature, however is often low in the subzero Celsius region.
Temperature is believed, does not effect radioactivity.
Maybe we are looking in the wrong direction. Cold temperature increases radioactivity and a specific temperature \(T_{v\,p}\) maximizes it.