The owners of the shutdown Three Mile Island nuclear power plant said today that if they are not granted at least a $33 million rate increase, they face bankruptcy.

"We need a tourniquet, and we need a transfusion," James B. Liberman, general counsel of General Public Utilities Corp., told the Pennsylvania Public Utilities Commission. "If this commission does not want to see this company in bankruptcy, it will permit the costs of the accident to be shared by investors and customer alike," he said.

Liberman said that unless the PUC grants Metropolitan Edison Co., the operator of Three Mile Island and one of three GPU subsidiaries, at least a $33 million rate increase, Met Ed would be unable to borrow the money it needs to pay for the accident.

Met Ed earlier had won a $49.2 million rate increase as a result of bringing Three Mile Island Unit 2 (TMI 2) on line, generating electricity. A PUC staff report had recommended that hearings be reopened on that rate increase, since TMI 2 will not be generating any electricity for "the forseeable future."

The company's plea today was to get at least $33 million of that $49.2 million increase despite that fact. The rate increase originally was set to go into effect March 29, the day after the accident, but the date is delayed pending the rehearing. In addition to the rate increase, the company is automatically passing along to comsumers the price of buying replacement electricity.

"We have very limited resources to meet our obligations," Liberman said. "If we can't borrow, we'd obviously have to go into bankruptcy and if we don't get rate relief the banks will not come forward with new funds. If this commission does nothing, I don't know if we could borrow a single dime tomorrow.'

Facing three state utility commissioners and a hearing room overflowing with people, Liberman insisted that Med Ed must borrow $28 million in April, $20 million in May and $19 million in June if it is to buy replacement electricity, meet its payroll and pay what he said are the straggering costs of the Three Mile Island accident. He set the recovery costs for the accident alone before any cleanup can be attempted at $8 million in April, $12 million in May and ar least $5 million in June.

"Since the accident, we've had more than 2,000 people come to Three Mile Island who need meals, housing and salaries," Liberman said. "This is a cash budget that is not being shared. Med Ed is picking up the bill."

The way Liberman put it to the PUC, the electric company is willing to forgo $16 million of the $49.2 million it won six days before the accident shut down TMI 2. But he insisted that Met Ed be granted the rest because utility could not tolerate the costs of the accident by itself.

"Investors simply cannot bear the whole burden of such an enormous event," Liberman said. "We need some revenue coming in to persuade the banks that they should continue to loan money to this corporation."

Liberman said that if Med Ed is granted the $33 million it asks, then the bank will lend it money "up to our legal limit." Liberman said Met Ed has borrowed $30 million on a legal limit he said could not exceed $97 million before this September.

Arguing that the entire rate case hearing should be reopened, PUC staff sttorney Joseph J. Malatesta Jr. said that any question of a rate increase should be suspended while the PUC hears how long Three Mile Island will stay shut down and how much the accident will cost.

Also speaking against Met Ed's request, state Consumer Advocate Mark P. Widoff accaused Liberman of attempting to get the PUC to bail Met Ed out of the difficulties in which the accident put it.

Before the three-hour hearing in the state capital, the Nuclear Regulatory Commission's Harold C. Denton bid farewell to Three Mile Island and the township of Middletown, wherwe it's located, after a 19-day stay supervising the hundreds of enginers and technicians who came from all over the country to deal with the accident.

"It's hard for me to realized I've been here 19 days," Denton said."I've consider my task here completed."

Before leaving, Denton said the radioactive iodine releases plaguing the recovery operation since last Saturday had been stopped. He said Met Ed technicians replaced iodinee filters in an auxiliary building had removed 20 contaminated filters before replacing any with fresh filters..

"I had assumed conventional practice was to take one filter out and replace it with a new one," Denton said. "The company thought they could do the job faster by taking all the filters out at once. We have now replaced all 20 filters and the iodine releases are down to negligible levels." CAPTION: Picture, The stricken Three Mile Island nuclear generating facility near Harrisburg. AP