The National Labor Relations Board has impounded ballots from an election at Duquesne University to decide whether adjuncts there can form a union. The ballots will be sealed until the NLRB rules on an appeal by the university. Duquesne, a Roman Catholic university, previously agreed to the election, but then decided to challenge it on the grounds that its religious affiliation exempts it from an union election. The Pittsburgh office of the NLRB denied that motion to withdraw from the election but the university appealed the decision to the national office. The election ballots were to be counted Tuesday, after a mail-in election.