Like most baseball fans last October, technicians at a plant handling the delicate business of reprocessing nuclear fuel at a U.S. government research center near here had World Series fever.

But their preoccupation with the televised action in the ninth inning of the final game occurred exactly at the same time as an accident that caused an unexpected chain reaction, the release of radioactive gas and an emergency evacuation when high radiation alarms rang while the game ended, 7-2.

Government investigators have said that if the men had been monitoring gauges instead of watching the Yankees beat the Dodgers, they could have noticed that the slow buildup of uranium in the system was becoming critical.

Plant officials confirmed this week rumors circulating in state offices in Boise that a shift supervisor smuggled a television set into the plant last Oct. 17. The plant is operated by the Allied Chemical Corp. for the U.S. Department of Energy.

The plant, at the Idaho National Engineering Laboratory 60 miles west of Idaho Falls, was reprocessing a 550-kilogram batch of uranium from spent fuel rods for use again in nuclear power plants.

There was no mention of the unauthorized TV set in a report on the accident released by Allied Chemical. The report blamed the incident on a defective valve, which leaked water into a radioactive solution of aluminum nitrates, causing the diluted solution to accumulate 60 times more dissolved uranium than normal.

The high concentration, the report said, led to a momentary chain reaction, which released a burst of radioactive krypton and xenon gas from the plant's venting stack. "No exposures of consequence" to humans occurred from this burst, according to the company.

The plant was closed for a month and 1,500 workers were laid off while the accident was investigated. The shift supervisor, whom company officials decline to name, was fired, and several employes were reassigned, said Francis Anderson, general manager of the Allied operation.

Anderson and several other officials confirmed that there was an unauthorized TV set in the plant, but said there had not been any attempt to "cover up" this fact. Anderson said, however, that he did not know about the TV set until after the investigation was completed.

He said that the valve began leaking water into the radioactive solution a month before the alarm bells rang. "Criticality would have occurred if the supervisor was or wasn't there," he said.

Other company officials insisted there was no connection between the employes' preoccupation with the televised game and the accident. But a government investigator said that if the men had been monitoring gauges they might have noticed the critical buildup of uranium in the solution.

The solution was housed in a 12-foot-tall, dumbellshaped processing column. At the moment the solution approached critical mass, an informant said, the supervisor and most of the technicians were watching the game in a lunchroom 60 feet from the operations area.

The plant's safety devices shut down the reaction in one second, said Steve Vorndran, a DOE employe assigned to monitor the plant for the federal government.

"The consequences were minimal - not because we were lucky, but because it's the way we designed the system," Vorndran said. "The plant was designed to endure those kind of accidents without effect."

But, Vondran said. "The plant was designed to endure those kind of accidents without effect."

But, Vondran said, had the supervisor or any of the plant's seven shift operators checked the monitoring devices - which is not a required task - they would have seen the slow buildup of radiation in the column. And if a recording chart had not run out of paper two weeks earlier, he added, they would have noted the "grossly" diluted strength of the solution.

"The fact that the TV was in there was certainly embarrassing to the company," said W. Lyle Slagle, chairman of the committee that wrote the report. "We took steps to ensure that it would not happen again. It was an indication of a bit of a lax attitude."

The report listed 11 deficiencies that may have contributed to the accident, noting "unprofessional" logbook entries (such as one that began "Dear Diary") that showed "contempt for the company," and a serious morale problem among workers.

Since the accident, Allied has extensively reviewed operating procedures. Allied's contract to operate the plant expires in October, and the firm has not sought to renew the contract.