May 7, 1983

The rate of unemployment in April, remainedat the March level of 10.1 percent of the labor force, but the nation's employment situation ''improved considerably,'' the Labor Department said today. Dr. Janet L. Norwood, Commissioner of Labor Statistics, said the data showed there had been considerable improvement in the labor market. ''Employment rose, particularly in the hard-hit manufacturing industries,'' she told the Joint Economic Committee of Congress. ''Equally important, the average number of hours worked last month expanded sharply and the amount of overtime increased.''

The operator of the Salem nuclear power plant in southern New Jersey was fined $850,000 by the Nuclear Regulatory Commission today for violations of Federal nuclear safety regulations. It was the largest fine ever imposed on a nuclear plant operator for safety deficiencies. The Public Service Electric and Gas Company, the operator of Salem, has 30 days to pay the fine, appeal it or seek a reduction. A spokesman for the utility, Bryan Smith, said officials wanted to take ''some time'' before deciding what to do.

The Israeli Cabinet voted today to accept in principle a draft agreement with Lebanon on border security and mutual relations. The accord is intended as a basis for the withdrawal of Israeli forces from Lebanon, provided the Palestine Liberation Organization and the Syrian Army also leave. Security in Southern Lebanon The agreement would provide for intimate involvement by Israel in security operations in southern Lebanon. But without a Syrian and P.L.O. pullout, the Lebanese-Israeli accord will probably not go into effect.

County officials in the area around the Indian Point reactors said yesterday that they did not plan to take any additional steps in response to the threat made by the Nuclear Regulatory Commission to shut the nuclear plants. State and Federal officials said, however, that they planned to meet in Albany next week to discuss how they could avert a shutdown. The N.R.C. threatened Thursday to close the two plants on June 9 if progress was not made in resolving ''significant deficiencies'' in emergency evacuation plans for Westchester and Rockland Counties. The leaders of the two counties said yesterday that they had been working for months to correct these defects. They said they hoped to have solutions in hand by the end of the year, but not by the commission's deadline.

The Interior Ministry said today that examination by state archivists and tests by police laboratories had determined that volumes purporting to be Hitler's secret diaries were forgeries. After initially resisting the weight of the official findings, Henri Nannen, the publisher of Stern, which had started to serialize the diaries, tonight also pronounced them a forgery and promised to expose their authors. In a television interview in his Hamburg office, he said: ''We are going to uncover the full story of this forgery and lay it before our readers. We have reason to be ashamed before our readers.''