Three Mile Island: federal help for cleanup?

Today, 21/2 years after the historic accident at the Three Mile Island (TMI) nuclear power plant, its owner-operators believe they may finally be seeing the first glimmer of light at the end of the tunnel.

This guarded optimism is rooted in the growing acceptance on the part of the federal government, local officials, and the nuclear industry of the fact that the $1.03 billion costs of cleaning up the stricken reactor must be shared. This consensus has been forged largely by the efforts of Pennsylvania Gov. Richard Thornburgh. He has been pushing a plan that would divide equally between national and local sources the costs of the unprecedented cleanup.

Earlier this week, Energy Secretary James Edwards told two congressional committees the administration would urge Congress to appropriate $123 million for TMI-related activities, a pronouncement Governor Thornburgh saluted as ''a giant step forward.'' This compares favorably with the $37 million for TMI now appropriated but not approved by Congress. But it is $67 million short of the 25 percent share that the governor would like the federal government to assume.

The management at General Public Utilities (GPU), owners of TMI, said in a statement Oct. 20 it was ''highly encouraged'' by the reports. But the utility remains cautious, in part because of uncertainty over what portion of the money would cover actual cleanup and what would go for related federal research activities, such as analysis of the damaged core.

In a letter to Governor Thornburgh, presidential adviser Edwin S. Meese III also promised significant federal financial support but clearly rejected any ''open-ended'' commitment on the part of the administration.

GPU's insurance only covers $300 million of the $1 billion estimated for the cleanup, leaving $700 million which must come from other sources. Over the last three years the utility has used up all but $80 million of its insurance money. To clean up the reactor in another six years would take about $136million per year. Because of its dire financial straits, GPU has had to cut its cleanup activities down to a $50 million annual level.

At the reactor itself, the highly radioactive krypton gases released into the reactor building have been vented into the air slowly with no apparent adverse effects. And 500,000 gallons of mildly contaminated water have been cleaned and are stored in tanks on site.

Another 100,000 of the 800,000 gallons of more highly contaminated cooling water in the reactor building have been cleaned and stored. To complete the cleanup, the remainder of the cooling water remains to be purified, the reactor building cleaned and scrubbed to remove radioactive residue, and the damaged core gingerly removed.