UV - Stopping a UV Reactor PDC panel (2).docx

STANDARD OPERATING PROCEDURES Date: 10/25/12 Approved: ______________________ (Tyson Neely, Operations Manager) cc: William Dunivin, Director of Water Production Subject: Stopping a UV Reactor-PDC Panel SOP Introduction: It is possible to work on an individual UV Train PDC panel for maintenance pur...

STANDARD OPERATING PROCEDURES Date: 10/25/12 Approved: ______________________ (Tyson Neely, Operations Manager) cc: William Dunivin, Director of Water Production Subject: Stopping a UV Reactor-PDC Panel SOP Introduction: It is possible to work on an individual UV Train PDC panel for maintenance purposes, while the remainder of the UV Train remains online. Due to the requirement that we operate each UV Train with a minimum of 5 reactors online, the following procedure may be used on only one reactor at a time on a given UV Train. Procedure: Inform the Control Room Operator that work will be conducted on the UV Train. The following steps will not be noticeable to the operators on the PCS unless they are looking at the specific “Train Graphic” page of the reactor being serviced. The “HOA” switches (actually “Remote” “Off” “Local”) on the 6 UV Train PDC panels can be switched from “Remote” to Local” from the control panel without disrupting the reactor operation. Complete the following steps to stop the reactor from the Control Panel. Switch all running reactors from “Remote” to “Local”. If only 5 reactors are running then put the standby reactor to “Local” and allow it to start up to get all six reactors to run. This step should keep each reactor running “On Line” with no reduction of the “Total Flow Capacity” value that is listed on the UV Overview graphic page on Delta V. This is what will prevent a plant shut down. Wait for a minimum of 6 to 7 minutes for the “Standby Reactor” to complete it’s warm up and enter the “On Line” mode. PCS Logic has a 5 minute delay for UV Reactor warm up, but a 6 to 7 minute wait time should be enough time to confirm that the newly started reactor will not fail due to some other problem. After the “Warm Up” phase, confirm with the Control Room Operator that the status of the UV Reactor indicates that it is “On Line” at the PCS panel switch. Once all the reactors are confirmed “On Line”, you may secure the reactor chosen for service by switching from “Local” to “Off” at the PDC Panel switch. Work can now be performed on the PDC panel only. At no time can work be performed on the actual UV reactor due to the interlock switch that is located on the end cap of each reactor. The switch remains active even when the PDC panel has been powered off, but the train remains on line. After completing the service work required on the PDC panel, the reactor may be restarted. Put the “HOA” switch to “Local” and warm up the unit as previously described above. When this process is completed, the Reactors can be switched back to the “Remote” mode. There should be no change in the reactors operating condition except for the following: If there were only 5 reactors on line at the start of the service work, then the first reactor that gets switched back to the “Remote” mode from “Local” will drop out to “Standby”. Each successive reactor changed from ‘Local” to “Remote” will then remain on line without any disruption in plant operations. Submitted by Nights 2 RS,9/4/12, Revised by JRS 10/25/12