new corrosion resistant metals which could sustain prolonged periods of intense radiation, thick shielding to protect personnel from radiation, and new components which would operate safely and reliably.

These problems were even more difficult for submarine application since the reactor and its associated steam plant had to fit within the confines of the comparatively small hull, and be able to withstand extreme battle shock incident to the operation of combatant ships. The propulsion plant had to be operated and maintained at sea by