Disclosed embodiments include methods of assembling a vented nuclear fission fuel module. Given by way of non-limiting example and not of limitation, an illustrative method of assembling a vented nuclear fission fuel module includes receiving a nuclear fission fuel element capable of generating a gaseous fission product. A valve body is coupled to the nuclear fission fuel element, and the valve body defines a plenum therein for receiving the gaseous fission product. A valve is disposed in communication with the plenum for controllably venting the gaseous fission product from the plenum. A flexible diaphragm is coupled to the valve for moving the valve. A cap is mounted on the valve, and a manipulator extendable to the cap for manipulating the cap is received.