PRELIMINARY HAZARDS SUMMARY REPORT FOR THE VALLECITOS SUPERHEAT REACTOR

Technical Report · Wed Feb 01 04:00:00 EST 1961

OSTI ID:4072150

Murray, J L

BS>The Vallecitos Superheat Reactor (VSR) is a light-watermoderated, thermal-spectrum reactor, cooled by a combination of moderator boiling and forced convection cooling with saturated steam. The reactor core consists of 32 fuel hurdles containing 5300 lb of UO/sub 2/ enriched in U/sub 235/ to 3.6%. The fuel elements are arranged in individual process tubes that direct the cooling steam flow and separate the steam from the water moderator. The reactor vessel is designed for 1250 psig and operates at 960 to 1000 psig. With the reactor operating at 12.5 Mw(t), the maximum fuel cladding temperature is 1250 deg F and the cooling steam is superheated to an average temperature of about 810 deg F at 905 psig. Nu clear operation of the reactor is controlled by 12 control rods, actuated by drives mounted on the bottom of the reactor vessel. The water moderator recirculates inside the reactor vessel and through the core region by natural convection. Inherent safety features of the reactor include the negative core reactivity effects upon heating the UO/sub 2/ fuel (Doppler effect), upon increasing the temperature or void content of the moderator in the operating condition, and upon unflooding the fuel process tubes in the hot condition. Snfety features designed into the reactor and plant systems include a system of sensors and devices to detect petentially unsafe operating conditions and to initiate automatically the appropriate countermeasures, a set of fast and reliable control rods for scramming the reactor if a potentially unsafe condition occurs, a manually-actuated liquid neutron poison system, and an emergency cooling system to provide continued steam flow through the reactor core in the event the reactor becomes isolated from either its normal source of steam supply or discharge. The release of radioactivity to unrestricted areas is maintained within permissible limits by monitoring the radioactivity of wastes and controlling their release. The reactor and many of its auxiliaries are housed within a high-integrity essentially leak-tight containment vessel. (auth)

• Research Organization: General Electric Co. Atomic Power Equipment Dept., San Jose, Calif.
• NSA Number: NSA-15-012557
• OSTI ID: 4072150
• Report Number(s): GEAP-3643
• Country of Publication: Country unknown/Code not available
• Language: English

Related Subjects

CONTROL
CONTROL ELEMENTS
COOLING
GAS FLOW
LEAKS
MAINTENANCE
MONITORING
NEUTRONS
POISONING
RADIOACTIVITY
REACTOR TECHNOLOGY
REACTORS
RODS
SAFETY
SERVOMECHANISMS
SHUTDOWN
SUPERHEATING
TRANSPORT
URANIUM
VESSELS
WASTE DISPOSAL
WATER MODERATOR