Safety Guidelines for Accelerator Installa Tions

The most difficult safety task is to identify a potential hazard or admit that it exists. Corollaries to existence are the magnitude of the potential accidents, and the probability of their occurrence. Once the hazards are identified there appears to be no shortage of guidelines and rules. But collecting rules is not the total answer to safety either. There must be a reasonable correspondence between the rules and the practice while the hazard exists. AEC safety guidelines for high-energy accelerator facilities are reviewed, and a bibliography of applicable codes is given in the Appendix. Several current safety problems are discussed. Liquid hydrogen distance tables seem to be fixed now. The forced ventilation of buildings containing liquid hydrogen has not afforded any protection against the two major fires resulting from large hydrogen spills. The possibility of spark-induced explosions in hydrogen purifiers or liquefiers is calculated to be very high and emphasizes the need for a low-temperature helium-gas purge.