A more thorough inspection yesterday of the second, smaller acid-created cavity on top of the reactor vessel head at the Davis-Besse nuclear plant initially shows less corrosion than expected, a FirstEnergy spokesman said.

Workers yesterday machined out a tight-fitting control rod nozzle next to the small cavity to get a better look at the damage apparently created by a boric acid leak. The 150-ton carbon steel vessel head is a vital safety component that covers the radioactive fuel core.

``It looks to be about what they thought it was earlier,'' plant spokesman Richard Wilkins said. ``If anything, it's actually smaller than we thought it was. They'll be taking a closer look at it over the next few days.''

The nozzles allow special rods to be inserted into the reactor chamber to control the fission process. A large, 6-inch-deep cavity was found next to one of the reactor head's 69 nozzles in early March after the plant was shut down in mid-February for refueling and a safety inspection.

Boric acid, part of the reactor coolant, apparently leaked through hairline fractures in what is called nozzle No. 3 and ate entirely through the vessel head's carbon steel exterior. A thin layer of stainless steel lining kept the acid from creating a bad ``loss of coolant'' accident inside the plant in Oak Harbor, about 25 miles east of Toledo.

The second, much smaller cavity was subsequently found at adjacent nozzle No. 2.

Wilkins said nozzle No. 2 probably will be capped off and the control rod device for that specific nozzle moved to a backup nozzle at another location on the reactor vessel head.

The Nuclear Regulatory Commission will hold a public meeting tomorrow at Oak Harbor High School to announce findings by its team of inspectors. The meeting starts at 9 a.m. The school is at 11661 W. State Route 163.

The NRC will hold another meeting April 10 at its Rockville, Md., headquarters, where FirstEnergy will present plans to repair the acid-created damage. The NRC can reject any repair plans and force FirstEnergy to replace the damaged vessel head, a process that could keep the plant closed for two years or longer. FirstEnergy has said it expects repairs will cost between $5 million and $10 million and keep the plant closed through at least the end of June.

Nozzle cracking became an industrywide issue after cracks were found in nozzles at other power plants. But Davis-Besse is the first nuclear plant found with cavities that apparently are related to the nozzle cracking issue.

The NRC subsequently ordered the 68 other similar nuclear power plants in the country to ensure that they don't have the same kind of damage. Those reports were due at the NRC yesterday. An NRC spokesman said a final tally on the reports won't be available for a couple of days.