The two defendants charged with deliberately damaging fuel rods at the nuclear power plant here testified today they did so only after the plant management ignored their complaints about alleged safety and health hazards at the plant.

"There was never a day that went by that I didn't raise an objection to what I saw," said William E. Kuykendall who, along with James A. Merrill Jr., worked as a control room operator trainee at the plant owned and operated by Virginia Electric and Power Co.

"I was extremely frustrated and upset and it didn't seem I was getting anywhere," testified Merrill.

Neither defendant was allowed to discuss the specific hazards they claim to have seen at the plant because of a ruling earlier in the day by Circuit Court Judge Ligon L. Jones. He ruled the two men could only describe their "state of mind" last April 27 when they deliberately caused at least $810,000 worth of damage to 62 spare fuel rod assemblies at the plant.

Vepco has refused to comment on any charges by the defendants until the conclusion of the trial -- considered the nation's first involving deliberate destruction by employes at a nuclear plant. In a statement last summer, the company contended it had an open door policy of welcoming and investigating employee complaints.

Today's testimony was marked by constant and often acrimonious legal objections, as defense attorneys struggled to elicit as much evidence about conditions at the plant as possible and prosecutors opposed them.

The judge generally sided with the prosecutors, at one point even sustaining an objection before assistant prosecutor H. Woodrow Crook Jr. could make it.

At a later point, Crook charged that defense lawyer Richard Ben-Veniste's continued and prolonged objections to Crook's questions were an effort to feed Kuykendall the right answers -- a charge Ben-Veniste hotly denied. He accused Crook of constantly interrupting Kuykendall in mid-answer.

The judge also ruled out defense references to the Three Mile Island nuclear power plant accident and to the reasons why the two Surry reactors are presently shut down, and quashed an effort to show that Kuykendall had been exposed to excessive radiation during the four months he worked at the plant.

It was Kuykendall, 26, a graduate of the Navy's nuclear reactor training program and a onetime conscientious objector, who emerged today in two hours of testimony as the architect of last April's incident.

He told the jurors in a firm and forceful voice that he chose the spare fuel rods in the fuel building as a target because damaging them would not affect the safe operation of the plant or disrupt electrical service.

"Why 64 (fuel rod assemblies)? Why not one?" asked Crook on cross-examination. (Actually two of the 64 assemblies were not harmed.)

Kuykendall answered that damaging one would not have taken long enough to prove to the company how lax security at the building was.

"What I did took an hour and 20 minutes," said Kuykendall. A saboteur could easily have lifted and exposed to the atmosphere highly radioactive spent fuel rods located in the same building within 10 or 15 minutes and could have "killed everybody in the plant and in a large part of Virginia," he said.

Why didn't Kuykendall simply resign his job in protest, asked Crook.

"Because to have done so would have been a cop-out to everyone in this room," said Kuykendall. "If I had resigned my employment and something had happened at that plant I would have had to live with if for the rest of my life."

Five character witnesses described Kuykendall as a deeply religious man. It remains to be seen how much impact his Christian beliefs will have with the nine woman, three man jury, all residents of this rural county of 6,000 where church-going is an important part of life.

Merrill, 24, who spoke in a soft, hesitating manner, said he did not consider damaging the fuel rods until Kuykendall suggested it on the morning of April 27. He testified that he did not know that the caustic soda he and Kuykendall poured on the fuel would cause extensive damage.

The defense and prosecution will make their concluding statements tomorrow morning, after which the case will go to the jury.