For those that measure reference bank worth by dilution during physics testing, how do you determine when to stop the dilution?
The process for Beaver Valley is to start a dilution with ARO and the reference bank at near ARO. The dilution is compensated for by inserting the reference bank (measured with a reactimiter supplied by the vendor). The goal is terminate the dilution so that less than 75 pcm is left in the reference bank. Contingencies are built in if you "overshoot" to insert another bank then borate it back out. Contingencies are also built in if you come up short of 75 pcm to dilute the bank into less than 75 pcm. We have experienced both under and overshoots here which is fine and allowed by procedure, we are just looking to see if there is a more precise method.
Travis B. Link Beaver Valley Reactor Engineering P.O. Box 4 - Mail Drop A-BV-A Shippingport, PA 15077 (724) 682-4149 (Work) (412) 667-1487 (Cell) (412) 305-3041 (Pager) (724) 682-4250 (FAX) tlink@firstenergycorp.com