31. The plant was closed in February 2002 for routine maintenance when inspectors found corrosion on the reactor vessel . 32. The reactor vessel is a steel cylinder with a diameter and height of, and a wall thickness of. 33. The blocks are stacked inside the reactor vessel into a cylindrical core with a diameter and height of. 34. However, the reactor vessel weighs 300 tons with the coolant inside, and that can pose some transportation difficulties. 35. But he was trapped in the reactor vessel compartment by a buildup in air pressure that jammed the hatches. 36. Greenpeace claims there are cracks in the reactor vessel larger than the safety limit, but offers no documentary evidence. 37. Almost certainly the hydrogen was formed inside the reactor vessel with the hydrogen subsequently vented into the containment building. 38. The core barrel and the reactor vessel wall form a cylindrical shell that is referred to as the downcomer. 39. The plant underwent refurbishment in 2006 by having its reactor vessel head, low pressure turbines and main transformer replaced. 40. After heating up in the core, pumps force the liquid fuel through heat exchangers positioned inside the reactor vessel .
