Document kD2DeR1n06oJw15M8X2pgpNKE

PI WTU & EC/HCL PROCEDURE FOR CELL LIQUOR AMD WASTE CAUSTIC HEADER CHANGES NORMAL OPERATIONS: Normally both the waste caustic and main cell liquor headers will be in service. Cell liquor is supplied to TE-2, VC-2, and VDCM. Waste caustic is supplied to CPC, BAT, the Incinerators and Waste Tech. If waste caustic strength goes too low or their ability to supply the needed flow rate fails, then it will be necessary to switch all of Plant B to cell liquor. The WTU Lead Operator will contact the EC/HCL Lead Operator to request that the cell liquor valve east of the EC Cooling Tower be opened. WTU will also be responsible for notifying Plant A Caustic that we are switching to cell liquor. The EC/HCL operators should not operate the valve if it is tagged out. WTU or Plant A Caustic personnel are responsible for tintagging this valve. See details below. The EC/HCL operator is not expected to ''check out the line" in this instance. There will be pressure on both sides of the valve when they are asked to open it. When waste caustic resumes normal operations, they will notify WTU. WTU will then ask EC/HCL to close the cell liquor valve. MAINTENANCE: If maintenance is required on the main cell liquor header, Plant A Caustic personnel will be responsible for tagging and clearing. One valve they will tag closed will be the valve at the EC Cooling Tower. If maintenance is required on the header to WTU, then WTU personnel will be responsible for clearing and tagging. Once again the valve at the EC Cooling Tower will be tagged closed. EC/HCL's participation in these maintenance activities will b minimal. However, they may be directed by WTU or Shift supervision to pull a tag on the valve at the cooling tower or to open the valve. SL 010714