Letter: an acceptable level for decommissioning By Vermont Yankee Posted February 23, 2018 In VY News 2018-02-232018-03-09http://vydecommissioning.com/wp-content/uploads/2019/01/northstar_logo.pngVY Decommissioninghttp://vydecommissioning.com/wp-content/uploads/2019/01/northstar_logo.png200px200px 0 0 Shaffer: 15 millirem is both an acceptable and conservative radiation level to prescribe for a greenfield project.