The electrical circuits controlling the reactor control rods are monitored, and an electrical failure in one or more circuits will result in a fast insertion or “scram” action. Should electrical power to the control rod drives fail completely, the hydraulic drives will be actuated. WASTE STORAGE AND HANDLING This system drains and collects, until safe for removal, all drainage from the reactor system that might be radioactive. Drainage may result from a leak, or be part of the normal drainage accumulation during initial fill and testing, normal startup, operation and shutdown, and decontamination. The drainage and storage system consists of two pumps, valves, piping, containment drain tank, and four waste storage tanks. The total capacity of the tanks is 1,350 cubic feet. This is approximately 80 percent more than the maximum operational leakage and drainage for a 100-day period. Provisions are made to take samples from any of the five tanks at any time. After sampling indicates sufficiently low level of activity, the fluid will be pumped to special dock facilities for transfer to inland waste disposal sites. No waste will be discharged at sea under present operating plans. A special 129-foot vessel, the NSV ATOMIC SERVANT, will service the Savannah’s reactor and handle the radioactive wastes. The majority of the potentially radioactive gases vent into a central manifold. Here they are monitored, diluted by fan-driven air and discharged up the radio mast after passing through a series of filters. During normal operation, the manifold is vented continuously. However, if the radiation monitor indicates activity levels too high for satisfactory dilution, the gases can be diverted into the containment shell. GAS FILTERED, MONITORED The region between the containment vessel and the secondary shielding is ventilated with a 4,000 cfm fan which discharges about half way up the radio mast. This gas is not expected to be radioactive but as an added precaution it is monitored to determine if radioactivity is present. All gases released through the radio mast are filtered to remove particulate matter. The containment shell air is purged with fresh air periodically at sea and prior to entry by the ship’s engineering crew. During normal operation the only radioactive gas in the shell is argon-41, at a concentration less than the maximum permissible level for continuous occupational exposure. The only potential sources of activity in the containment air above tolerance levels would be fission products and these are not present during normal operation. However, as previously described, prior to purging, air samples will be analyzed to ascertain the activity levels. HEALTH PHYSICS MONITORING SYSTEM