  Liquid Argon Time Projection Chambers are planned to comprise a central role
in the future of the U.S. High Energy Physics neutrino program. In particular,
this detector technology will form the basis for the 40 kton Deep Underground
Neutrino Experiment (DUNE). In this paper we take as a starting point the dual
phase far detector design proposed by the DUNE experiment and ask what changes
are necessary to allow one of the four 10 kt modules to be sensitive to heavy
Weakly Interacting Massive Particle (WIMP) dark matter. We show that with
control over backgrounds and the use of low radioactivity argon, which may be
commercially available on that timescale, along with a significant increase in
light detection, one DUNE-like module gives a competitive WIMP detection
sensitivity, particularly above a dark matter mass of 100 GeV.
