Installation of an Emergency Stop Panel

A NIST-owned liquid nitrogen (LN2) 3,000-gallon bulk tank services the NIST Biorepository and Cryogenic Reference Material Production Facility at the Hollings Marine Laboratory in Charleston, SC. The bulk tank was installed ~1999-2000 during the construction of the Hollings Marine Laboratory. At that time, a control system was not available at the tank that would assist in monitoring automated cryogenic systems that uses inert gas, such as nitrogen, to assure an oxygen deficient atmosphere would not occur. The bulk tank is set up as a low-pressure tank that provides LN2 to all LN2 vapor-phase freezers of the NIST Biorepository and backup systems to the -80 °C upright freezers. Additional equipment of the Cryogenic Reference Material Production facility also uses LN2 from this bulk tank for the production of frozen standard reference materials (SRMs) and control materials (CMs). Each LN2 vapor-phase freezer has a relief valve on it and in the event of a blockage or excessive pressure, several relief valves may vent nearly simultaneously, causing a “whiteout” condition in a matter of seconds. Visibility can drop to near zero and oxygen levels in the area may become less than that necessary to sustain life. This type of emergency situation can occur if the bulk tank is accidentally over-pressurized during an LN2 bulk tank fill. Currently there are no measures in place to immediately isolate the bulk tank from the pipe system to avoid creating an oxygen deficient atmosphere inside the laboratory which could lead to a life-safety event. Therefore, the bulk tank must be installed with such a system to ensure the cryogenic system is operating safely before, during, and after an LN2 service fill. It is imperative that the installation of the E-Stop and O2 Monitor System be completed in a timely manner to ensure the safety of staff working in the laboratory space but also to avoid any delay of delivery of LN2 to the freezers and equipment in the NIST Biorepository and Cryogenic Reference Material Production Facility. In order to install the Estop and O2 Monitoring system, a section of the MVE vacuum-jacketed piping must be removed and replaced at the point nearest the LN2 bulk tank. And in order to do this the LN2 bulk tank must be completely emptied of LN2 product. Once the work is completed, the tank must be refilled with liquid nitrogen. A full function test and associated documentation will be required to ensure the new E-Stop, oxygen monitor and new piping section is properly operating.

Division 02 -	Existing Conditions, Subsurface Investigation.
Division 03 -	Concrete, Concrete Reinforcing, Cast-in-Place Concrete.
Division 05 -	Metals, Structural Metal Framing, Metal Decking.
Division 23 -	Heating, Ventilating, and Air Conditioning (HVAC), Facility Fuel Piping, Facility Fuel-Storage Tanks.
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