Super Collider Egress Spacing and Life Safety

Abstract

For the 53-mile tunnel of the Superconducting Super Collider (SSC), egress points are planned at an unprecedented spacing of five miles. In studying egress spacing with regard to life safety, no codes were found dealing specifically with accelerator tunnels. “General” codes were found which specify egress spacing not greater than several hundred feet. However, these “general” codes are neither for occupancies like the SSC nor do they credit the many overlapping safety features found in SSC conceptual design. A search for standards in counterpart underground activities disclosed a safety code for non-coal mines which prescribes egress requirements that the SSC surpasses. Egress-related risks for SSC hazards were cataloged and found less profound than those for mining. Thus, the SSC egress-related injury rate should be less than that currently accepted in the mining industry. (The overall injury rate in mining is below the national average for industry at large.) As a further check, Fermi National Accelerator Laboratory was used as an extrapolation model for an egress-related injury rate study. Fermilab, with a statistically relevant database, has an injury rate below the national average. Of all accelerator tunnel injuries over its 18-year history, there were none for which probability of occurrence or severity of outcome would have been affected had egress spacing been either reduced from the present 800 ft. or increased by several miles. If the injury history experienced at Fermilab is acceptable, and if the extent to which the SSC surpasses non-coal mine requirements is satsfactory, there should be no reason to alter SSC egress spacing from the five-mile intervals now planned.