Sen. David F. Durenberger (R-Minn.), chairman of the Select Committee on Intelligence, yesterday criticized the Central Intelligence Agency and its director, William J. Casey, for lacking a "sense of direction" and particularly for failure to understand the Soviet Union.

Durenberger said his committee will consider recommending legislation that would substantially downgrade the CIA director's role and make the president's national security affairs adviser responsible for evaluating intelligence in the policy-making process.

His criticisms notwithstanding, Durenberger also defended Casey as a "professional" and "a darn good guy in that job" who deserved to continue as director.

Durenberger said, however, that a vote today in his Republican-dominated committee over whether to recommend Casey's dismissal in the wake of the CIA's handling of the Soviet defector Vitaly Yurchenko would be 8 to 7 in support of the director, a vote reflecting party lines.

Yurchenko defected to the West in August, but three months later apparently changed his mind and publicly denounced the CIA as kidnapers and torturers before returning to Moscow last week.

Durenberger's comments during a luncheon with reporters indicated that the Yurchenko affair has brought to a head serious differences between Congress and the CIA over the performance of both bodies in a series of recent disclosures of classified information.

He also acknowledged that his own attempt to redefine his committee's oversight role to encourage the public release of more information had created "an uncomfortable feeling" in Congress and "other places" about the wisdom of "that kind of course of action."

Durenberger centered his criticisms of the CIA's leadership on what he called its failure to provide overall guidelines to employes in gathering and analyzing information, particularly data regarding the Soviet Union.

"They aren't getting any sense of direction. They aren't being told what it is in the long run we need [to know] about the Soviet Union," he said.

Durenberger said he was not faulting the quality of CIA personnel or the agency's resources. Rather, he lambasted "a process that doesn't let them look five years down the road" or allow the agency to consider in their longer-range evaluations such brewing crises as the Philippines, the rise of Shiite Moslem fundamentalism in the Middle East or what he called "the energy factor."

He faulted the absence of any "sense of a national intelligence strategy," a problem he said his committee was hoping to remedy by providing additional CIA funds beginning this fiscal year.

Durenberger said another problem facing the intelligence community is a redefinition of the respective roles of the CIA and the National Security Council.

The Senate intelligence committee probably will recommend before the end of 1986 that the president's national security affairs adviser "ought to be really the person who is responsible for the linkage between intelligence and policy," while the CIA director is restricted to "professional intelligence work." Casey, who was Reagan's campaign director in 1980, has been a close adviser to the president.

The senator also disclosed that he is drafting a letter to Casey in the wake of Yurchenko asking for information on how the defection was handled, what the CIA and others have learned from the affair and who in the agency is accountable.

Durenberger said that 50 percent of past Soviet defectors had returned home as Yurchenko did in a "relatively short period of time." The senator said it was important for the CIA and the Congress to understand the phenomenon if the United States hoped to encourage other Soviets to defect.

The senator also defended Congress against administration charges that it had been responsible for various "leaks" about Yurchenko's defection. He said the administration had been guilty of "selective leaking" during the three months Yurchenko was in U.S. custody.