The work presented deals with tokamak plasma turbulence in the case wherefluxes are fixed and profiles are allowed to fluctuate. These systemsare intermittent. In particular, radially propagating fronts areusually observed over a broad range of time and spatial scales. Theexistence of these fronts provides one possible way to understand thefast transport events sometimes observed in tokamaks. It is also shownthat the confinement scaling law can still be of the gyro-Bohm type inspite of these large scale transport events. Some departure from thegyro-Bohm prediction is observed at low flux, i.e. when the gradientsare close to the instability threshold. Finally, it is found that thediffusivity is not the same for a turbulence calculated at fixed fluxas for a turbulence calculated at fixed temperature gradient, with thesame time averaged profile.