The external recirculation pumps and piping have been replaced by ten internal recirculation pumps mounted to the bottom head. These Reactor Internal Pumps (RIPs) are improved versions of those used in Europe for which there is over 1000 pump years of operating experience. The reliability and durability of these pumps has proven to be so good that only two will be removed for servicing during an outage. The RIP motors are continuously purged with clean water to keep crud from settlling into them from the vessel, so that radiation levels around the pums are vastly reduced.