Replacement of the Reactor Cooling Pump Motor

In order to preserve the plant availability and reliability NEK has decided to buy a new RCP motor. On the basis of Investment Program and Technical Specification SP-S700A the replacement RCP motor has been ordered as fit, form and function replacement motor to existing KRK-125 motors including certain upgrades to like-for-like replacement.

The new RCP motor was manufactured by Westinghouse / Curtis-Wright EMD at EMD facility in Cheswick, PA, USA. The EMD shop order D039 was assigned to the job and will be used to uniquely identify the motor and trace its design, production and test records and documents to NEK. New D039 motor was connected mechanically, electrically and instrumentally to the plant like the existing one and replaced the KRK-125 motor (S/N 1S86P550) on RCPCPC01-MTR location in 2007 outage.


Detailed design modification package (DMP) for modification 576-RC-L addressed all aspects of the new D039 RCP motor interfaces and/or upgrades of existing interfaces required to properly control and/or supervise motor functions. The existing alarm and/or the trip set-points are not changed by modification. Additional instrumentation devices (oil level transmitters, bearing RTD’s and vibration sensors) were interfaced to the plant Process Information System. The new oil spill protection system has been installed which provides means to collect and store any oil spill from the motor.





Picture 1: The new RCP motor with Oil Spill Protection System


The implemented activities did not present any functional changes from the existing design of RC pump motor basic function which would have negative affect on the normal plant operating parameters nor the safeguards systems actuation or the accident mitigation capabilities of the plant. The same design and construction of the reactor coolant pump motor critical parts are utilized on D039 and 86P550 motors. The inertia of motor and pump rotating parts is equal in D039 motor as it was in the 86P550 motors and thus the coast down flow characteristics is not changed from those analyzed in SAR.








Picture 2: Handling the RCP motor

The plant reliability and availability is increased as in the case of an RCP motor failure the third (spare) motor is available on site. This also allows the refurbishment of the motor exempted from the service. In the same time the DMP 576-RC-L provided solutions for the third (spare) motor long term storage and maintenance activities in FHB 100.300 location.                                            

Project Manager: Božidar Linke, B.Sc.E.E.