With fuel leaks, STP typically first sees an increase in Xe-133. Later, sometimes not until there is a power reduction or trip, we see a definite increase in RCS iodine. We usually don't see cesium in the RCS except following a reactor trip with a leaker; and sometimes we've had trips or large downpowers with leakers and still not seen cesium. I believe we have always seen cesium following the final shutdown and cooldown when there was a leaker in the core.
Duane Gore STP
-----Original Message----- From: respvr-bounces@retaqs.com [mailto:respvr-bounces@retaqs.com] On Behalf Of ALDAY, CLINT L Sent: Monday, February 06, 2006 8:19 PM To: 'RE Supervisors' Subject: [Respvr] Iodine/Cesium Mismatch Question
Has anyone seen an increase in RCS iodine activity in the RCS without a concurrent cesium indication? Xe-133/135 also increased. This occurred at steady state, full power conditions - no opportunity for washout from an existing failed rod. We are puzzled by the lack of cesium as all our models indicate that it should be present when the iodine increase occurred.
Clint Alday Reactor Engineering Waterford 3 calday@entergy.com _______________________________________________ Respvr mailing list Respvr@retaqs.com http://www.keffective.com/mailman/listinfo/respvr