The Senate's anxiety over questions of integrity goes public today as its ethics committee opens two weeks of televised hearings on charges that Sen. Dave Durenberger (R-Minn.) may have engaged in financial wrongdoing that "brought discredit" on the Senate.

The trial-like hearings before the Senate Select Committee on Ethics are the first in nearly a decade in which a senator has been put in the public dock to defend himself against charges of violating the chamber's ethical standards and rules.

"These charges are serious; it will be a very serious proceeding," said committee Vice Chairman Warren B. Rudman (R-N.H.), who joined with the panel's chairman, Howell T. Heflin (D-Ala.), in outlining procedures for the hearings.

Not since Harrison A. Williams (D-N.J.) resigned in the midst of disciplinary hearings over his involvement in the Abscam scandal in 1981 have ethics charges against a senator been considered serious enough to merit public hearings by the ethics panel.

The Durenberger hearings, for which 200 possible witnesses have been contacted, may be just the beginning of an ordeal of self-scrutiny that will test the Senate's self-discipline. In addition to the allegations against Durenberger, the committee is weighing charges against six other senators, including five who are accused of improperly intervening on behalf of savings and loan executive Charles H. Keating Jr. Preliminary action is expected shortly in the case of the "Keating Five."

The committee also is considering charges that Sen. Alfonse M. D'Amato (R-N.Y.) improperly intervened with federal agencies to benefit relatives and political supporters.

These cases are coming to a head just as the Senate is starting to deal -- inconclusively so far -- with a heavy ethics-related agenda that includes overhaul of loophole-ridden campaign financing laws and a proposal to stop senators from collecting honoraria for speeches to special interest groups.

Campaign finance reform remains bogged down in a partisan dispute over Democratic-proposed spending limits. Meanwhile, the Senate, which last year refused to join the House in raising members' salaries while banning honoraria, is heading into an election-year fight over the issue.

The potential for abuse in the honoraria system figures prominently in the charges against Durenberger, a 55-year-old lawyer who has served in the Senate since 1978 and who was once regarded as one of the rising stars of the Republican Party in the squeaky-clean tradition of Minnesota politics.

In one set of charges, the committee has found "substantial credible evidence" to conclude that Durenberger evaded Senate honoraria limits by having his fees for speeches to outside groups sent to Piranha Press Inc., which in turn paid him $100,000 in stipends for helping sell books he had written for the publishing firm.

The committee also found that Durenberger may have improperly failed to report travel reimbursements for speeches promoting the books, converted a campaign contribution to personal use and accepted fees for promotional appearances in Senate rooms in violation of a prohibition on such commercial use of the space.

Another charge centers on questions of whether he violated conflict-of-interest rules in accepting about $5,000 worth of limousine service in connection with book promotion speeches in Boston while he was visiting a marriage counselor in that area.

The committee also said Durenberger may have abused his office and misused taxpayer funds in several ways in connection with seeking and receiving Senate reimbursement for rent at a Minneapolis condominium in which he held an interest. Specifically at issue is whether he submitted misleading vouchers, misrepresented ownership of the property, backdated a partnership agreement in order to justify earlier reimbursements and violated rules in his handling of a blind trust that included the condo.

Durenberger has acknowledged what he called "lapses in judgment" in dealing with his personal finances but said it was "never my intent to circumvent Senate rules for my own benefit" and contended that he "made every effort" to seek official advice before taking the actions in question.

While Senate rules allow a negotiated settlement of ethics charges, the committee and Durenberger were apparently so far apart in their positions that negotiations never got off the ground.

The hearings will begin with opening statements from committee members, committee counsel Robert S. Bennett and Durenberger. After both sides present their cases, the committee will recommend a finding and disciplinary action, if warranted. Options range from exoneration to expulsion, with an almost infinite variety of steps in between, including censure, condemnation and reprimand. In any case, the final verdict is expected to come from the Senate itself.