D0 Detector Assemble Hall Platform Oxygen Deficiency Hazard Analysis
Liquid cryogens, released and warming to atmosphere conditions, expand to, on average, seven hundred times their liquid volume, and displace vital atmospheric oxygen. An oxygen deficiency hazard analysis assesses the increased risk to personnel in areas containing cryogenic systems. The D0 detector platform area ODH analysis has been approached four different ways using established methods. In each case, the analysis shows the platform area to be ODH class 0 as equipped (with ventilation fans) and requiring no special safety provisions. System designers have provided for a reduced oxygen level detection and warning system as well as emergency procedures to address fault conditions. The Oxygen Deficiency Hazard of any particular area is defined by these parameters: the nature of the accidental supply of inert gas (probability of occurrence and quantity then released), the area's volume, the area's ventilation rate, and to a small degree the elevation of the area. Once this information is assembled, the ODH classification can be determined through standardized calculations. The platform area under the D0 detector contains much of the cryogenic and gas system piping necessary for the D0 experiment. Prior to moving the detector into the Collision Hall, the liquid argon calorimeters are cooled down and operated in the Assembly Hall. The first phase of this operation involved the cooldown of the Central Calorimeter, which was done in February 1991. This engineering note assesses the increased risk to personnel in the platform level to a reduced oxygen atmosphere during the cool down and subsequent operation of the calorimeters in the Assembly Hall. In addition, it outlines the steps taken to warn personnel of an emergency and to direct the subsequent evacuation. This note analyses only the Assembly Hall area. A similar engineering note, EN-332, covers the analysis of the Collision Hall area.
- Research Organization:
- Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States)
- Sponsoring Organization:
- USDOE Office of Science (SC)
- DOE Contract Number:
- AC02-07CH11359
- OSTI ID:
- 1031837
- Report Number(s):
- FERMILAB-D0-EN-258; TRN: US201201%%1026
- Country of Publication:
- United States
- Language:
- English
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