Work to replace the nuclear reactor head at FirstEnergy Corp.’s Davis-Besse powerplant could cost up to $405 million--and will reduce 2002 earnings by some $155 million--the Akron, Ohio-based utility said. The lengthening of downtime at Davis-Besse related to head replacement due to severe boric acid corrosion, now slated to end in early 2003, allows FirstEnergy to add some $27 million in maintenance projects formerly slated for future planned outages. “We have to check all other systems which may have been affected by the leak, and some we’ve determined can be replaced now,” says FirstEnergy spokesman Ralph DiNicola. Head replacement will cost between $55 million and $75 million, most of which will be capitalized. Substitute power for the loss of Davis-Besse’s 925-Mw capacity will cost between $110 million and $145 million. Operation and maintenance expenses now are pegged at between $115 million and $135 million in 2002, and $50 million in 2003, up from $50 million to $70 million.