  The launch of the Hinode satellite has allowed unprecedented high resolution,
stable images of solar quiescent prominences to be taken over extended periods
of time.
  These new images led to the discovery of dark upflows that propagated from
the base of prominences developing highly turbulent profiles.
  As yet, how these flows are driven is not fully understood.
  To study the physics behind this phenomena we use 3-D magnetohydrodynamic
(MHD) simulations to investigate the nonlinear stability of the
Kippenhahn-Shl\"{u}ter prominence model to the magnetic Rayleigh-Taylor
instability.
  The model simulates the rise of a buoyant tube inside a quiescent prominence,
where the upper boundary between the tube and prominence model is perturbed to
excite the interchange of magnetic field lines.
  We found upflows of constant velocity (maximum found 6\,km\,s$^{-1}$) and a
maximum plume width $\approx 1500$\,km which propagate through a height of
approximately 6\,Mm in the no guide field case. The case with the strong guide
field (initially $B_y=2B_x$) results in a large plume that rises though the
prominence model at $\sim 5$\,km\,s$^{-1}$ with width $\sim 900$\,km (resulting
in width of 2400\,km when viewed along the axis of the prominence) reaching a
height of $\sim 3.1$\,Mm. In both cases nonlinear processes were important for
determining plume dynamics.
