DAB, South Side, ODH Analysis

Abstract

This report covers the ODH concerns of the south side of the D0 Assembly Building. from the bottom (el. 700-feet) to the top (774-feet 6-inches). volume by volume. Each volume is covered in its own section. with each section broken down into three parts. The first is a description of the volume. including its function. dimensions. and all relative ODH concerns; cryogenic piping and ventilation. Second. the actual ODH analysis of the volume is shown. Third. the provisions for the ODH condition of the volume are detailed. including securing the area and the posting of signs. The liquid argon dewar room is at an elevation of 701-feet 6-inch (38-feet underground), with the dewar surrounded by 7700 cubic feet of air. The area is accessible only through a single door. which has a small window and a lock (lock out only). There is small metal scaffolding in front of the dewar to facilitate maintenance and U-tube pulling and installation. The room is directly on top of the Pipe Chase Well and the Cryo Sump, and the bottom of the Stairway is just outside the door. The dewar is designed to be completely operated by remote computer control and the area will be unmanned during normal operation. Room occupancy will occur only during dewar or central control junction box maintenance, or U-tube changes. The dewar has these additions to it: 20 valves, 10 bayonet connections (or 5 U-tubes), 8 bolted flanges, 100 pipe sections (approx.). 100 brazed joints and welds (approx.). and 10 pipe elbows. In addition, 3 of the U-tubes will be changed twice a year on average.