The above photos illustrate the use of heating elements placed in concrete at the time the concrete is poured. These devices are thermostatically controlled to operate without manual intervention. The main sidewalk leading out the north door of the control room and the entire exterior walkway that will surround the enclosure should have these built in. Not only do they allow for unobstructed walkways but also require no hand-shoveling of snow. Due to the arched nature of the main enclosure, snow will tend to fall down and to the sides of the main arch. Having heated concrete below those areas will greatly reduce the buildup of snow and/or ice.     The hardware on the left is 36" wide and used for sidwalks. The hardware on the right is used to heat steps, which may be incorporated into the enclosure's design.