Inside Report (6)

The AFL-CIO flexes its muscle over National Labor Relations Board (NRLB) appointments.

The AFL-CIO won its fight against confirmation of John R. Van de Water as chairman of the NLRB. Now it will urge the Senate to reject assistant secretary of labor Donald Dotson, named by President Reagan as member and chairman of the NLRB, which is charged with protecting workers and employers from unfair labor practices.

Mr. Van de Water will leave office Dec. 16 after being rejected by the Senate because of his management background.

Mr. Dotson is opposed by the AFL-CIO for basically the same reason; the federation says that as a former management attorney, he ''lacks the neutrality expected of an NLRB member and, especially, the board chairman.