Using On-line Monitoring of Fission Products Data to Manage Reactor Operations with In-Core Failed Fuel Element(s)

Abstract

Increases in iodine activity in the Primary Heat Transport System (PHTS) coolant as a result of fuel sheath failures can threaten Unit operation if the iodine coolant activity limit in the Primary Heat Transport System (PHTS) is approached. However, shutting down the reactor increases significantly the difficulty associated with localizing failed fuel bundles. Additionally, such an action poses significant economic implication. As a result, it is important to develop methodologies that can be used to proactively manage coolant iodine concentration under different operating conditions (including startup after an outage with suspected failed fuel in the Unit) while localization efforts continues.