This project is to assess and implement the installation of redundant oil pumps for the reactor feedwater pump turbines (RFPT). The RFPT main shaft driven oil pumps have been unreliable, with limited operating range, and have had a difficult and expensive repair and maintenance history. Due to the unreliable operation of the RFPT main shaft driven oil pumps, a single RFPT motor driven auxiliary oil pump must be continuously operated to maintain RFPT oil system pressure requirements. The recent failure of a single RFPT auxiliary oil pump resulted in the loss of over $100,000 in generating revenue (18 hours of reduced power). The recommendation to correct this problem involves two options. The first option would be to add one new motor driven pump with the current auxiliary pump. A second option would be to purchase two new motor driven pumps to replace the current configuration, as recommended by General Electric.

This project will be successful if a corrective action option is selected that will improve plant availability and plant capacity and will reduce maintenance requirements for the RFPTs.

II. EVALUATION

Schedule Index: 30 - The prevention of power reductions due to failures in the present RFPT system and lost generation time will increase the unit capacity (1.0 x 10). The plant will also be enhanced by the improved maintenance and lower repair costs for the proposed upgrade to the RFPT oil pumps (1.0 x 8). Nuclear safety is somewhat improved with a more reliable feedwater system which will reduce the potential for a loss of feedwater transient (0.2 x 32). The addition of the motor driven auxiliary oil pumps for the RFPTs could prevent previous unit power reductions associated with the present system thus increasing unit availability (0.5 x 12).

Economic Aspects: The economics of replacing a difficult and expensive to maintain RFPT main shaft driven oil system with a more reliable and easier to maintain system are positive. Besides the savings in maintenance, there is also a savings in generating capacity with increased reactor feedwater reliability. Just one failure of the RFPT auxiliary oil system cost 18 hours of reduced generating capacity or $100,000 of lost revenue. The cost of upgrading both units could be economically justified with the prevention of potential lost generating revenue over the balance of plant life. Long term maintenance costs would be reduced relative to the present RFPT oil system.

Related Standards: Replacing the RFPT oil pumps with a more reliable system would meet the Work Management Policy on material condition. This policy is met by maintaining and improving the reliability and productivity of the Brunswick Nuclear Plant with a more reliable reactor feedwater system.

Other Considerations: Because this project requires the reactor feedwater system to be inoperable for the replacement of the RFPT oil pumps the work would have to be performed during the B212R1 outage and B111R1 outage.

III. CONCLUSION

The project is scheduled to be performed in the B212R1 outage and in the B111R1 outage. This will allow adequate time for design and outage planning. The replacement of the RFPT shaft driven oil pumps with motor driven oil pumps would result in increased plant capacity, availability and reduce the maintenance cost of the reactor feedwater system. The added reliability of the reactor feedwater system will also enhance the safety of the Brunswick Nuclear Plant.