Exhibit 99.15

CONSENT OF ENGINEER

Ladies and Gentlemen:

The undersigned hereby consents to (1) the references to the undersigned’s name included or incorporated by reference in the Annual Report on Form 40-F of Denison Mines Corp. in connection with (a) the report entitled “Technical Report on the Hairhan Uranium Exploration Property in Mongolia” dated March 23, 2011 and (b) the report entitled the “Technical Report on a Mineral Resource Update for the Phoenix Uranium Deposits” dated December 31, 2012, and (2) all other references to the undersigned included or incorporated by reference in the Annual Report on Form 40-F of Denison Mines Corp.

Dated: March 19, 2014

/s/ William Roscoe

William Roscoe, Ph.D., P.Eng.

Roscoe Postle Associates Inc.