DEVELOPMENT OF THE SRE THIMBLE-TYPE CONTROL RODS, MARK I AND II

Technical Report · Thu Oct 15 04:00:00 EDT 1959

OSTI ID:4233136

Miller, A E

Two thimble control rods were developed for the Sodium Reactor Experiment. In the Mark I design, all components, except the easily-removed drive motor assembly, are located below the reactor shield. The Mark I is presently limited by life expectancy to the slow and infrequent motion required of a shim rod. The Mark II, designed with the traversing mechanism located above the shield, is used for the fast and frequent regulating motion. All components of the control rods are protected from the sodium coolant by 23-ft-long stainless- steel "thimbles" that extend from the reactor loading face downward through the active corp. The nuclear poison elements of the control rods, formed by a series of short, hollow boron-nickel cylinders stacked on stainless-steel pull tubes, are moved vertically in a helium atmosphere by a recirculating ball-screw and nut. The clearance between the poison cylinders and the thimble wall, which permits adequate cooling of the cylinders, was determined from heat transfer experiments. Development and tests of the control rod components provided design information. Operation and life tests of prototype control rods were performed to establish their reliability under reactor temperature conditions. (auth)

• Research Organization: Atomics International Div., North American Aviation, Inc., Canoga Park, Calif.
• DOE Contract Number: AT(11-1)-GEN-8
• NSA Number: NSA-14-002204
• OSTI ID: 4233136
• Report Number(s): NAA-SR-2011
• Country of Publication: United States
• Language: English

Related Subjects

BORON
CONTROL ELEMENTS
CORROSION PROTECTION
CYLINDERS
HEAT TRANSFER
HELIUM
LIQUID METAL COOLANT
NICKEL
PLANNING
POWER PLANTS
REACTOR TECHNOLOGY
SODIUM
STAINLESS STEELS
TEMPERATURE
TESTING
TUBES