"Z" facility dielectric oil clean-up

In August of 1998, the Z facility leaked approximately 150 gallons of deionized water into the dielectric oil of its energy storage section (ESS). After processing the oil to remove existing particulate and free water, the dielectric breakdown strength increased from the mid 20 kV range to values in excess of 40 kV. 40 kV is above historical operating levels of about 35 kV. This, however, was not enough to allow 90 kV charging of the Marx generators in the ESS. Further analysis of the oil showed dissolved water at a saturated level (70-80 ppm) and some residual particulate contamination smaller than 3 microns. The dissolved water and particulate combination was preventing the 90 kV charging of the Marx Generators in the ESS. After consulting with the oil industry, it was determined that nitrogen sparging could be used to remove the dissolved water. Further particulate filtering was also conducted. After approximately 20 hours of sparging, the water content in the ESS was reduced to 42 ppm which enabled Marx charging to 90 kV.