HEAT TRANSFER AND STABILITY STUDIES IN BOILING WATER REACTORS. Quarterly Progress Report No. 6, April 1, 1962-July 1, 1962

Technical Report · Sun Jul 01 04:00:00 EDT 1962

OSTI ID:4764429

Changes made in the boiling loop are reported. A subcooler circuit was connected to the downcomer providing a control on the inlet temperature to the riser. This circuit was especially designed for a low pressure drop. The subcooler power can be adjusted by controlling the water flow through four spirals installed in the circuit. Fine control is obtained by a preheater. This preheater gave some difficulties caused by a change in isolation resistance between the heating wire and the sheath of the heating coil About 250 kw can be dissipated in the subcooler under conditions of natural circulation, giving a subcooling temperature of about 30 deg C at the inlet of the riser. A closer control of the secondary cooling water to the condenser, a remote level gage and a fast power control were installed. The void fraction method using scintillation counters was developed further. Some experiments were carried out regarding cooling, influence of magnetic fields and collimation on count rate. The stabilization of the amplification by the photomultiplier worked satisfactorily. New insulated thermocouples were installed for differential temperature measurements. It appeared, that the calibration is dependent on the value of The insulation resistance. A burn-out detector operating on a signal from a Wyheatstone bridge was developed and installed. The study of boiling noise and development of theoretical models was continued. Information is also given regarding the burn-out and instability experiments carried out on a seven cluster heating element. During the burn-out detector development it was shown that the form of the hot patch has a large influence on the burnout flux. A sharp hot patch has a significantly lower burnout flux than a shaped one for the same operating conditions. In some experiments the out-of-balance signal from the burn-out detector was recorded on a Visicorder. Periodic oscillations were observed on the trace at about the natural hydraulic frequency. These oscillations were tentatively identified with hydraulic instability. (auth)

• Research Organization: Eindhoven, Netherlands. Technische Hogeschool
• NSA Number: NSA-17-011980
• OSTI ID: 4764429
• Report Number(s): EURAEC-414
• Country of Publication: United States
• Language: English

Related Subjects

AMPLIFIERS
BACKGROUND
BOILING
BRIDGE CIRCUITS
BUBBLES
BURNOUT
CALIBRATION
CIRCUITS
CONDENSERS
CONFIGURATION
CONTROL
CONVECTION
COOLANT LOOPS
COOLING
DENSITY
DETECTION
DIELECTRICS
EFFICIENCY
ELECTRIC CONDUCTIVITY
ELECTRICITY
ELECTRONIC EQUIPMENT
EQUATIONS
FAILURES
FLUID FLOW
FUEL ELEMENTS
GAGES
HEAT EXCHANGERS
HEAT TRANSFER
HEATING
HIGH TEMPERATURE
HOT SPOT
HYDRAULICS
IN PILE LOOPS
INSTRUMENTS
IRRADIATION
LIQUID FLOW
LOSSES
LOW TEMPERATURE
MAGNETIC FIELDS
MATERIALS TESTING
MEASURED VALUES
MOCKUP
MONITORING
NEUTRON FLUX
OSCILLOGRAPHS
PHOTOMULTIPLIERS
PLANNING
POWER
POWER PLANTS
PRESSURE
QUANTITA
REACTOR TECHNOLOGY