At Wolf Creek we are the same way. We provide guidance for withdrawing control rods and do a 1/M plot, but for Shutdown Banks, the operators pull them a bank at a time watching the NI's to make sure there are no large changes in source counts. We verify Boron Concentration prior to pulling any rods, but do NOT provide specific guidance for pulling the Shutdown Banks. Normally, the Shutdown Banks are pulled well in advance of pulling the Control Banks in preparation for a startup. We still dilute to criticality following a refuel shutdown.
-----Original Message----- From: pwrrm-bounces@retaqs.com [mailto:pwrrm-bounces@retaqs.com]On Behalf Of BRYSON, DAMON V Sent: Thursday, June 08, 2006 9:59 AM To: pwrrm@keffective.com Subject: [Pwrrm] Shutdown bank withdrawal guidance question
Benchmarking question:
At VC Summer we have detailed procedure guidance for the operators on how to withdraw control rods during the approach to criticality. However, we do not have any procedure guidance on how to withdraw shutdown bank control rods. Some of our operators withdraw the shutdown banks continuously while watching other indications. Some of them stop every 25 steps to look at other indications, and then continue on. Others stop every 25 steps and ask for supervisor concurrence before continuing.
What kind of guidance do your plants have on withdrawing shutdown banks? You can email me at the address below, and I will compile all the responses and share them with the entire group. Thanks in advance for your help.
Damon Bryson
(803) 345-4814
dbryson@scana.com