As its third essence claim, the Union challenges as inconsistent with the Handbook the Arbitrator’s failure to reject awards nomination forms received after the deadline in the Handbook. Union’s Exceptions at 14. Based on his interpretation of the relevant Handbook language, which he found ambiguous, and the facts and circumstances of the case, the Arbitrator found that the Union had failed to demonstrate that the nominators -- and not the receiving officials -- were responsible for the untimely nominations. Award at 15. He also found that the Union had failed to demonstrate that any employee had received an unfair advantage because the nominations forms may have been received a day or two late, or that any employee was responsible for the lapse. Id. Based on those findings, he found no violation of the timeliness requirements of the Handbook. Id. The Union has provided no basis for finding that the Arbitrator’s interpretation is irrational, unfounded, implausible, or in manifest disregard of the Handbook. Accordingly, we deny the Union’s third essence exception.