Vermont Yankee completes refueling

Entergy Vermont Yankee announced Friday that it had completed refueling of the nuclear power plant in Vernon. During the refueling the plant does not produce electricity. The refueling and maintenance outage began April 28. Vermont Yankee reports the plant is now in a state called demobilization, in which scaffolding and other equipment related to the completed work is being removed. Vermont Yankee states that much of the work has involved upgrades to improve the plant’s long-term reliability, such as the replacement of a reactor feed pump motor, sleeving the plant’s condenser tubes, and completing the third (and final) phase of the cooling tower upgrades, including the safety-related section of the west tower.
The refueling of the reactor involved the changeout of 116 spent fuel assemblies for new assemblies and the rearranging of the remaining 252 assemblies in the reactor core. The total number of specialized outage workers needed to refuel the plant was 668 as of last week, down from a high of more than 800.
The testing and inspection of major plant components so far this outage has included the reactor internals, the main steam isolation valves and various heat exchangers. Engineers are analyzing the data gathered on the condition of the reactor internals including the reactor vessel and the steam dryer. Of the eight main steam isolation valves leak-rate tested, two were found to need work on their seating surfaces to bring them into very precise specifications.
One of the major jobs this outage was the scheduled cleaning of the plant's torus that contains a back-up supply of cooling water at the base of the reactor building. That work is done approximately every six years and involves very specialized divers with submersible vacuuming equipment.
The final stage of the outage will be switching and valving of plant systems from their maintenance mode to their normal operations mode and final tests in preparation for start up.
Vermont Yankee also stated that work on the soil remediation from the tritium leak continued through the outage and is on schedule to be completed in the coming weeks.
Source: Entergy Vermont Yankee. 5.14.2010