Shutdown of acid drains 10/9-10/10

Dick Crane rcrane at stanford.edu
Thu Oct 5 15:18:02 PDT 2006


Labmembers and CISX labs users:

The acid waste neutralizer system which services both CIS (including the 
SNF fab) and CISX buildings will be shutdown from 0600 on Monday, 
October 9 until 1000 (exact turn-on time to be announced) on Tuesday, 
October 10, for an emergency repair. This action will affect all lab 
sinks, wet benches and fume hoods. The system has developed a leak in 
one of its mixing tanks which will be repaired, tested and then 
certified prior to returning to service.

Please do not use any acid waste drain lab sinks or wet benches after 
0600 on Monday. Please do not resume operation until "system is up" 
notices have been posted. Since the exhaust fume scrubbers operate using 
recycled neutralizer waste water, our fume scrubbers will be down during 
this repair. Exhaust air flow will be normal, but the fume loading needs 
to be minimized. Please cover any and all chemicals in fume hoods to 
reduce evaporation. Hot pots should be drained prior to 0600 on Monday.

SNF fab: All wet benches and SRDs will be down during the repair. This 
will effectively shut down diffusion, wet etch, some of thin film and 
some of the litho areas. What will be up and available includes litho 
coat and develop tracks, exposure, ebeam, thin film dep tools (for 
wafers not requiring a wet clean prior to loading), analytical tools, 
and dry etch tools.

The details: The acid waste neutralizer system servicing CIS and CISX 
buildings was built in 1983 and consists of two, 1,000 gallon mixing 
tanks and a 500 gallon final sampling tank and lift tank. Tanks are 
continuously checked for leaks via a floor level moisture detector. The 
tanks are visually inspected weekly and checked annually. The center 
tank has developed a seepage which needs to be repaired with a 
fiberglass build-up. After repairs have cured, the tanks will be 
hydrostatically tested and the  certified by a PE from a tank inspection 
firm.

Thanks for your cooperation and sorry for the inconvenience,

Dick




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