(The Center Square) – Kennewick’s 81,000-square-foot convention center is set to more than double in size over the next two years despite voters already rejecting two tax proposals to pay for the project. The decision to proceed with the massive expansion came last week as the city council approved an $8 million internal loan to the Kennewick Public Facilities District, which manages the Three Rivers Convention Center. The funding will allow the PFD to determine the project’s maximum cost and perform any early site preparation as developers prepare to break ground in December. The expansion in…