Temperature noise analysis and sodium boiling detection in the fuel failure mockup

Conference · Thu Jan 01 04:00:00 EST 1976

OSTI ID:7343776

Sides, Jr, W H; Fry, D N; Leavell, W H; Mathis, M V; Saxe, R F

Sodium temperature noise was measured at the exit of simulated, fast-reactor fuel subassemblies in the Fuel Failure Mockup (FFM) to determine the feasibility of using temperature noise monitors to detect flow blockages in fast reactors. Also, acoustic noise was measured to determine whether sodium boiling in the FFM could be detected acoustically and whether noncondensable gas entrained in the sodium coolant would affect the sensitivity of the acoustic noise detection system. Information from these studies would be applied to the design of safety systems for operating liquid-metal fast breeder reactors (LMFBRs). It was determined that the statistical properties of temperature noise are dependent on the shape of temperature profiles across the subassemblies, and that a blockage upstream of a thermocouple that increases the gradient of the profile near the blockage will also increase the temperature noise at the thermocouple. Amplitude probability analysis of temperature noise shows a skewed amplitude density function about the mean temperature that varies with the location of the thermocouple with respect to the blockage location. It was concluded that sodium boiling in the FFM could be detected acoustically. However, entrained noncondensable gas in the sodium coolant at void fractions greater than 0.4 percent attenuated the acoustic signals sufficiently that boiling was not detected. At a void fraction of 0.1 percent, boiling was indicated only by the two acoustic detectors closest to the boiling site.

• Research Organization: Oak Ridge National Lab., Tenn. (USA); North Carolina State Univ., Raleigh (USA)
• DOE Contract Number: W-7405-ENG-26
• OSTI ID: 7343776
• Report Number(s): CONF-761001-18
• Country of Publication: United States
• Language: English

Related Subjects

21 SPECIFIC NUCLEAR REACTORS AND ASSOCIATED PLANTS
210500* -- Power Reactors
Breeding
ACCIDENTS
ACOUSTIC MONITORING
BOILING DETECTION
BREEDER REACTORS
EPITHERMAL REACTORS
FAST REACTORS
FBR TYPE REACTORS
FLOW BLOCKAGE
FUEL ASSEMBLIES
FUEL ELEMENT FAILURE
LIQUID METAL COOLED REACTORS
LMFBR TYPE REACTORS
MOCKUP
MONITORING
NOISE
REACTOR ACCIDENTS
REACTORS
SIMULATION
STRUCTURAL MODELS
TEMPERATURE NOISE
TEST FACILITIES