Leak tightness design basis for HTGR cavity liners

The leak tightness design basis for the HTGR cavity liners is presented. A discussion is included of applicable codes and regulations, material qualification requirements, fabrication and examination practices, and leak testing procedures. The operating state and environment of the liner are described, and mechanisms that could potentially cause leakage are evaluated. It is concluded that the high standards of the construction practices combined with a benign operating environment ensure that the liner will maintain leak tightness throughout its operating life.