Winston Churchill publicly committed the UK to building a hydrogen bomb, and gave the scientists a tight schedule in which to do so. This was then hastened after the US and USSR began working on a test ban and possible disarmament agreements which would begin to take effect in 1958. To meet this deadline there was no chance of building a new reactor to produce the required tritium, so the Windscale Pile 1 fuel loads were modified by adding enriched uranium and lithium-magnesium, the latter of which would produce tritium during neutron bombardment. All of these materials were highly flammable, and a number of the Windscale staff raised the issue of the inherent dangers of the new fuel loads. These concerns were brushed aside.