sentences:  Outlet temperature ranges between , which allows these reactors to generate hydrogen as a byproduct efficiently, thus supplying inexpensive and non-polluting fuel for fuel cell powered vehicles.HTR-10 is a pebble-bed reactor HTGR utilizing spherical fuel elements with ceramic coated fuel particles.The reactor core has a diameter of 1.8 m, a mean height of 1.97 m and the volume of 5.0 m³, and is surrounded by graphite reflectors.