Complex sentence: The reactors were built in a short time near the village of Seascale, Cumberland and were known as Windscale Pile 1 and Windscale Pile 2, housed in large concrete buildings a few hundred feet apart.
Split into simpler sentences: The reactors were built in a short time near the village of Seascale, Cumberland. They were known as Windscale Pile 1 and Pile 2, housed in large concrete buildings a few hundred feet apart.