NB Power said the earliest work could begin is the second quarter of 2027. Read More NB Power —Mactaquac LifeAchievement Project"New Brunswickers expect us to make careful, informed decisions about major investments in our electricity system," said Lori Clark, president and CEO of NB Power. The rehabilitation is required, NB Power said, because of alkali-aggregate reaction, a slow chemical process between minerals found in some concrete aggregates that, in the presence of moisture, causes the concrete to expand over time. Without major rehabilitation, the utility says the generating station would likely not be able to operate by about 2030. NB Power plans to replace the first generating unit in 2028 and 2029, and proceed with the remaining units through 2036.