Even as political tensions between China and Taiwan have mounted this year, the two have been secretly negotiating a surprising multibillion dollar deal in which more than 200,000 drums of radioactive waste from Taiwan’s nuclear power plants would be disposed of in mainland China in return for money and aid to the mainland’s nuclear power industry. Talks have been suspended in recent weeks, but officials of the Taiwan Power Co. hope they can resume this spring. Such a deal would represent a major reversal in Taiwan’s official policy of restraining commercial ties with the mainland, but Taiwan seems to be getting desperate to find storage for low-level waste that is piling up at its three nuclear plants. Last year, local protests erupted when the Taiwanese government indicated that it was considering building an undersea storage site near an outlying island group.