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Blockages in LMFBR fuel assemblies: a review

Description: Experimental and analytical investigations performed in the United States, Germany, Great Britain, and Japan on the effects of partial flow blockages in liquid-metal fast breeder reactor fuel assemblies are reviewed and the results presented. Generalized models are developed from experimental data obtained for blockages of various sizes, shapes, and porosity, with and without pins, utilizing water and sodium as the coolant. Generally, the recirculating flow in the wake behind a blockage is a re… more
Date: January 1, 1977
Creator: Han, J. T. & Fontana, M. H.
Partner: UNT Libraries Government Documents Department
open access

Heat-transfer in a partially-blocked sodium-cooled rod bundle. [LMFBR]

Description: Heat transfer coefficients were experimentally determined for 31-rod sodium-cooled bundle with a 6-subchannel central blockage. The Nusselt number is presented as a function of the Peclet number for both the free flow region undisturbed by the blockage and the wake region immediately downstream of the blockage. Results are compared with the existing correlations for liquid metals. The heat transfer coefficient was generally higher in the unblocked free flow region than in the wake region. A lea… more
Date: January 1, 1979
Creator: Han, J.T.
Partner: UNT Libraries Government Documents Department
open access

Edge blockage in a 19-pin sodium-cooled bundle. [LMFBR]

Description: To assess the effect of partial flow blockages on the local temperature distributions in LMFBR fuel assemblies, several experiments have been carried out at the Thermal-Hydraulic Out-of-Reactor Safety (THORS) Facility at the Oak Ridge National Laboratory. Two kinds of flow blockages have been investigated: (1) six-channel internal blockage for which the blocked channels are not adjacent to the duct wall, and (2) 14-channel edge blockage for which some of the blocked channels are adjacent to the… more
Date: January 1, 1977
Creator: Han, J. T.; Gnadt, P. A.; Fontana, M. H. & Wantland, J. L.
Partner: UNT Libraries Government Documents Department
open access

Analysis of closed-pool boilup using the TRANSIT-HYDRO code. [LMFBR]

Description: The benign termination of the transition phase of a hypothetical LMFBR accident rests on the avoidance of highly energetic recriticalities prior to escape of bottled molten core materials from the active core region. In scenarios where molten fuel is trapped due to axial blockages, the maintenance of subcritical configurations until radial flow paths develop requires stable boil-up of the molten fuel/steel mixture. This paper describes the analysis of an experiment investigating the behavior of… more
Date: January 4, 1983
Creator: Graff, D.L.
Partner: UNT Libraries Government Documents Department
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FRAP-GCFR: a code for the transient analysis of gas-cooled fast reactors

Description: The fuel rod analysis computer program (FRAP-T) has been modified to analyze transient fuel rod behavior in the gas cooled fast reactor (GCFR). Major features modeled include the effects of helium coolant, ribbed cladding, pressure equalization system, and 316 stainless-steel material properties. The code capabilities include models of elastic-plastic-creep deformation behavior, two-dimensional heat conduction, rod ballooning, and transient axial gas flow. The models are particularly relevant t… more
Date: January 1, 1979
Creator: Peck, S O; Hagrman, D L & Bohn, M P
Partner: UNT Libraries Government Documents Department
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Nuclear fuel powder flow characterization

Description: Based upon the flow characteristics of nuclear powders, a mass flow hopper required for dependable gravity flow would have outlet diameters of at least 11 inches (28 cm). Vibration of the hopper as well as storage in the hopper result in larger outlet openings for mass flow hoppers.
Date: April 1, 1979
Creator: Densley, P. J. & Carson, J. W.
Partner: UNT Libraries Government Documents Department
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Thermohydraulic and thermal stress aspects of a porous blockage in an LMFBR fuel assembly

Description: The current safety scenarios of Liquid Metal Fast Breeder Reactors (LMFBR) under local fault propagation include the study of a hypothetical accident initiated by the formation of an external debris porous blockage in a fuel subassembly. In this preliminary experimental and analytical investigation, a non-heat-generating porous blockage was postulated to cover 18 flow channels of a 37 pin Fast Test Reactor (FTR) type fuel subassembly. The axial extent of the blockage is 50 mm. The blockage mate… more
Date: January 1, 1979
Creator: Kuzay, T. M.; Marr, W. W.; Helenberg, H. W.; Ariman, T.; Wilson, R. E. & Pedersen, D. R.
Partner: UNT Libraries Government Documents Department
open access

Sodium Loop Safety Facility experiment P4. [LMFBR]

Description: SLSF experiment P4 was designed to provide an upper-limit bound on the consequences of local faults. Three of the 37 full-length FTR-type fuel pins in the test subassembly were built with 10-cm-long, sealed fuel canisters as the center sections of the fuel regions. The fuel canisters ejected molten fuel into the bundle geometry, as planned. Each ejection was accompanied by an inlet flow deceleration and persisting flow reduction. There was no evidence of energetic fuel-coolant interactions or f… more
Date: January 1, 1982
Creator: Ragland, W. A.; Braid, T. H.; Thompson, D. H.; Wilson, R. E.; Baldwin, R. D.; Kraimer, M. R. et al.
Partner: UNT Libraries Government Documents Department
open access

Effect of power skew on the FTR TOP

Description: An enduring program of studies, both experimentally and analytically, on the unprotected Transient Overpower Hypothetical Core Disruptive Accident (TOP-HCDA) of the Liquid Metal Fast Breeder Reactor (LMFBR) has been in progress for a decade or so. The data available from the experiments and the computational methodology improvements have made the recent TOP safety assessments more realistic. The evidences from the in-pile tests in the TREAT facility, such as the axial location of fuel pins' fai… more
Date: March 1, 1978
Creator: Yung, S.C. & Wilburn, N.P.
Partner: UNT Libraries Government Documents Department
open access

Plugging of intersubassembly gaps by downward flowing molten steel. [LMFBR]

Description: In the assessment of the meltout phase of an LMFBR hypothetical core disruptive accident, a pathway for the escape of molten fuel from the disrupted core is provided by the narrow channels separating adjacent subassemblies. However, the removal of fuel through intersubassembly gaps might be impeded by steel blockage formation, if molten steel is postulated to enter the gap network ahead of disrupted fuel. Reported here are the results of an analysis of the conduction freezing controlled penetra… more
Date: January 1, 1984
Creator: Sienicki, J. J. & Spencer, B. W.
Partner: UNT Libraries Government Documents Department
open access

Thermal analysis of a six-channel heat-generating blockage in an LMFBR

Description: This paper presents a case study of the temperature fields within and around a six-channel blockage designed as a molten-fuel-release initiator in SLSF-P4, an in-reactor experiment (37-mixed-oxide pin bundle) planned for February, 1981, irradiation. To meet the experiment objectives, a minimum of ten grams of molten UO/sub 2/ must be ejected into the sodium stream from one, two, or three such blockages. The temperature fields of the electrodeposited-nickel blockage filled with a mixture of UO/s… more
Date: January 1, 1980
Creator: Warinner, D. K. & Chao, D. H. Y.
Partner: UNT Libraries Government Documents Department
open access

Review of recent ANL safety experiments in SLSF and TREAT. [LMFBR]

Description: Among the recent significant in-pile experiments conducted by ANL are Sodium Loop Safety Facility (SLSF) experiment P4 in the Engineering Test Facility (ETR) and TREAT experiments F3, F4, and J1. The P4 experiment, which had three heat-generating flow blockages each installed in six coolant channels in a 37-pin bundle of FTR (Fast Test Reactor)-type fuel elements, investigated the bounding consequences of severe local faults. The principal objectives were to eject molten fuel into the bundle ge… more
Date: January 1, 1982
Creator: Klickman, A. E.; Thompson, D. H.; Ragland, W. A.; Wright, A. E.; Palm, R. G. & Page, R. J.
Partner: UNT Libraries Government Documents Department
open access

Quasi-steady state boiling downstream of a central blockage in a 19-rod simulated LMFBR subassembly (FFM bundle 3B). [Fuel failure mockup]

Description: Results of sodium boiling tests in a centrally blocked 19-rod simulated LMFBR subassembly are discussed. The tests were part of the experimental series conducted with bundle 3B in the Fuel Failure Mockup (FFM) at ORNL.
Date: January 1, 1976
Creator: Hanus, N.; Fontana, M. H.; Gnadt, P. A.; MacPherson, R. E.; Smith, C. M. & Wantland, J. L.
Partner: UNT Libraries Government Documents Department
open access

CAMEL II 37-pin/7-pin intra-pin fuel injection test

Description: It is concluded that the 2-D effects of this test allowed the coolant to bypass the injected fuel, prohibiting any significant intermixing of the fuel and sodium to take place. This lack of intermixing resulted in a benign pressurization event and significantly reduced the fuel sweepout over previous CAMEL tests. The resulting fuel blockage is predicted to be in a coolable state when analyzed with PLUGCO, a numerical computer code for analysis of post-transient blockage coolability.
Date: January 1, 1984
Creator: Wilson, R. J.; Spencer, B. W.; Erickson, E. G.; Dewey, G. & Hodges, R.
Partner: UNT Libraries Government Documents Department
open access

In-core coolant velocity measurements in a pressurized water reactor using temperature-neutron noise cross correlation

Description: Noise signals from an in-core, movable, neutron flux-mapping detector and a core-exit thermocouple at the Sequoyah-1 plant were cross correlated in order to investigate the feasibility of inferring in-core coolant flow velocities. If feasible, this technique might provide a cost effective way to detect local in-core flow blockages or to verify fuel assembly thermal-hydraulic performance. Previous ex-core neutron detector/core-exit thermocouple cross correlations at Sequoyah-1, indicated that, w… more
Date: January 1, 1984
Creator: Sweeney, F. J.
Partner: UNT Libraries Government Documents Department
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LMFBR Safety and Sodium Boiling

Description: Within the U.S. Fast Breeder Reactor Safety R and D Work Breakdown Structure for Line of Assurance 2, Limit Core Damage, the influence of sodium boiling upon the progression and termination of accidents is being studied in loss of flow, transient overpower, loss of piping integrity, loss of shutdown heat removal system and local fault situations. The pertinent analytical and experimental results of this research to date are surveyed and compared with the requirements for demonstrating the effec… more
Date: January 1, 1978
Creator: Hinkle, W. D.; Tschamper, P. M.; Fontana, M. H.; Henry, R. E. & Padilla, A., Jr.
Partner: UNT Libraries Government Documents Department
open access

The relationship between void waves and flow regime transition

Description: The results of an extensive experimental and analytical study on the relationship between void waves and flow regime transition are presented, in particular, the bubbly/slug flow regime transition. It is shown that void wave instability signals a flow regime transition.
Date: December 31, 1992
Creator: Lahey, R. T. Jr.; Drew, D. A.; Kalkach-Navarro, S. & Park, J. W.
Partner: UNT Libraries Government Documents Department
open access

Leakage flow-induced vibration of an unconstricted tube-in-tube slip joint

Description: The conditions are given for which the more flexible of two cantilevered, telescoping tubes conveying fluid can be self-excited by flow leaking from an unconstricted slip joint. Also, a physical explanation of the excitation mechanism is discussed, and a design rule to avoid the mechanism is presented. In addition, the results for the unconstricted slip joint are shown to be similar to those for slip joints having annulus constrictions at very short engagement lengths.
Date: December 1, 1986
Creator: Mulcahy, T. M.
Partner: UNT Libraries Government Documents Department
open access

PIV velocity measurements in the wake of an obstruction simulating a Taylor bubble in a duct

Description: Mean velocity measurements in the wake of an obstruction simulating a Taylor bubble (or slug) have been obtained using Particle Image Velocimetry (PIV) in a duct. Two flow rates were established: one represented the flow behind a large gas slug rising in quiescent fluid and the other represented an idealized slug rising with a higher relative velocity, as typically found in higher void fraction churn-turbulent flow. The results indicate that, in a reference frame fixed to the slug, the flow aro… more
Date: June 1, 1997
Creator: Vassallo, P. & Kumar, R.
Partner: UNT Libraries Government Documents Department
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