Gen. Edward Rowny (USA, ret.) chief US nuclear arms negotiator, said Wednesday preliminary problems have been cleared away and there is now a 50-50 chance a nuclear arms reduction agreement can be reached with the Soviet Union in 1983.
General Rowny added, however, that the US is dealing with a more sophisticated Soviet government and a new Soviet leader who knows how to ''twist words.'' Interviewed on NBC's ''Today,'' the general said, ''We have been making more rapid progress than we did in SALT, I would say, in the last six months. It took us about two years in SALT.'' Rowny is regarded as a hard-liner in negotiations with the Soviets.