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Title: GAS-COOLED REACTOR PROJECT QUARTERLY PROGRESS REPORT FOR PERIOD ENDING SEPTEMBER 30, 1960

Abstract

6 D E H & d methods of control-rod programing for operation of the Experimental Gas Cooled Reactor (EGCR) were evaluated. The three methods were (1) uniform bank operation of all rods, (2) partial or full insertion of a few selected control rods, and (3) full insertion of selected control rods snd uniform bank operation of the remaining rods. Calculations were made of the amount of heat that will be deposited in the EGCR control rods. The cases considered conformed with the method of control-rod programing suggested above. Calculations were also made of the gamma -ray heat deposition to be expected in the EGCR moderator and other core components. These data provide information needed for deter mining the over-all core cooling requirements. The hotchannel factors were determined for the EGCR core both for normal operation and for a channel with an additional 10% heat input. Criteria for the failure of EGCR fuel elements based on excessive temperatures and/or excessive fission-gas release were established. The maximum allowable temperature has been set at 1800 ha ,n)Cu/sup 67 F. Design data based on results of irradiation experiments on UO/ sub 2/ were applied to EGCR operating conditions, and the UO/sub 2/ temperatures andmore » the fission-gas pressure buildup were computed. A calculation of the pressure drop across the six fuel assemblies in the highest power channel gave a maximum value of 9.44 psi. The design of the EGCR control rods was modified to overcome difficulties encountered in attaching the central wire rope to the inside of the rod. The thermal characteristics of the modified rod were calculated in order to determine the effects on cooling requirements. Calculations were also made for determining the effect of the reactor radial-flux gradient on the circumferential variation in rod-cladding temperature and any subsequent rod bowing. Experimental data were obtained for a stress analysis of the EGCR pressure vessel. The channel entrance for the apparatus used in the study of the thermal characteristics of the EGCR fuel cluster was modified in an effort to correct for a flow maldistribution observed in earlier experiments. Circumferential temperature profiles were obtained for all seven tubes at 11 axial positions with the altered inlet configuration; the average Reynolds modulus was 50,500 and the surface heat flux was maintained at 6500 Btu/hr- ft/ sup 2./ An evaluation was completed of preliminary mass-removal measurements obtained in the study of the role of relative cluster orientation on the heat- transfer distribution in an EGCR fuel cluster. Mapping of the isothermal velocity field in the EGCR cluster was concentrated on the effect of relative cluster orientation on the velocities 0.05 in. from the rod surface at four axial levels. The measurements were restricted to a 120 ha ,n)Cu/sup 67 sector of the channel, embracing four rods. Materials Development: Work was continued in the development of a process for recovery of UC/sub 2/ by the nitrate-recycle process. Specimen pellets of UO/sub 2/ of two different grain sizes have been fabricated for use in prototype irradiation experiments. Thin plates of UC/sub 2/ and ThC/ sub 2/ were prepared for fission-gas-release experiments. The release-rate parameter for the release of Xe/sup 133/ was determined for additional grades of UO/sub 2/, including a specimen of fused oxide. Processes are being developed for the preparation of fueled graphite bodies. Graphite fueled with UC by an admixture method and fabricated into cylindrical shapes showed laminations and surface bumps due to partial oxidation of the UC during firing. The rate constants for the reaction of -60 +80-mesh UO/sub 2/ with graphite at reduced pressures were determined to be 0.18 at 1275 ha ,n)Cu/sup 67 C and 0.44 at l375 ha ,n)Cu/sup 67 C. Results indicated that the reaction rate is sensitive to particle size below about 1325 ha ,n)Cu/sup 67 C and relatively insensitive above this temperature. The elastic moduli of AGOT graphite were determined by the sonic method. On a specimen from a block prepared with needle coke, the Young's« less

Publication Date:
Research Org.:
Oak Ridge National Lab., Tenn.
OSTI Identifier:
4109928
Report Number(s):
ORNL-3015
NSA Number:
NSA-15-003778
DOE Contract Number:  
W-7405-ENG-26
Resource Type:
Technical Report
Resource Relation:
Other Information: Orig. Receipt Date: 31-DEC-61
Country of Publication:
United States
Language:
English
Subject:
GENERAL AND MISCELLANEOUS; BERYLLIUM OXIDES; CARBON DIOXIDE; CARBON MONOXIDE; CHEMICAL REACTIONS; CONFIGURATION; CONTROL ELEMENTS; CONTROL SYSTEMS; COOLANT LOOPS; COOLING; CRITICAL ASSEMBLIES; DEFORMATION; DENSITY; DISTRIBUTION; EGCR; ENERGY; EXPANSION; FABRICATION; FAILURES; FISSION PRODUCTS; FLUID FLOW; FORGING; FUEL CANS; FUEL ELEMENTS; FUSED SALT FUEL; GAMMA RADIATION; GAS COOLANT; GASES; GRAIN SIZE; GRAPHITE; HEAT TRANSFER; HEATING; HELIUM; HIGH TEMPERATURE; HOT WORKING; HYDROGEN; IMPURITIES; IN PILE LOOPS; JOINTS; LABORATORY EQUIPMENT; LEAKS; LEAVES; MATERIALS TESTING; MEASURED VALUES; MECHANICAL STRUCTURES; METHANE; MODERATORS; MOLYBDENUM; NEUTRON FLUX; NUMERICA

Citation Formats

. GAS-COOLED REACTOR PROJECT QUARTERLY PROGRESS REPORT FOR PERIOD ENDING SEPTEMBER 30, 1960. United States: N. p., 1960. Web. doi:10.2172/4109928.
. GAS-COOLED REACTOR PROJECT QUARTERLY PROGRESS REPORT FOR PERIOD ENDING SEPTEMBER 30, 1960. United States. https://doi.org/10.2172/4109928
. 1960. "GAS-COOLED REACTOR PROJECT QUARTERLY PROGRESS REPORT FOR PERIOD ENDING SEPTEMBER 30, 1960". United States. https://doi.org/10.2172/4109928. https://www.osti.gov/servlets/purl/4109928.
@article{osti_4109928,
title = {GAS-COOLED REACTOR PROJECT QUARTERLY PROGRESS REPORT FOR PERIOD ENDING SEPTEMBER 30, 1960},
author = {},
abstractNote = {6 D E H & d methods of control-rod programing for operation of the Experimental Gas Cooled Reactor (EGCR) were evaluated. The three methods were (1) uniform bank operation of all rods, (2) partial or full insertion of a few selected control rods, and (3) full insertion of selected control rods snd uniform bank operation of the remaining rods. Calculations were made of the amount of heat that will be deposited in the EGCR control rods. The cases considered conformed with the method of control-rod programing suggested above. Calculations were also made of the gamma -ray heat deposition to be expected in the EGCR moderator and other core components. These data provide information needed for deter mining the over-all core cooling requirements. The hotchannel factors were determined for the EGCR core both for normal operation and for a channel with an additional 10% heat input. Criteria for the failure of EGCR fuel elements based on excessive temperatures and/or excessive fission-gas release were established. The maximum allowable temperature has been set at 1800 ha ,n)Cu/sup 67 F. Design data based on results of irradiation experiments on UO/ sub 2/ were applied to EGCR operating conditions, and the UO/sub 2/ temperatures and the fission-gas pressure buildup were computed. A calculation of the pressure drop across the six fuel assemblies in the highest power channel gave a maximum value of 9.44 psi. The design of the EGCR control rods was modified to overcome difficulties encountered in attaching the central wire rope to the inside of the rod. The thermal characteristics of the modified rod were calculated in order to determine the effects on cooling requirements. Calculations were also made for determining the effect of the reactor radial-flux gradient on the circumferential variation in rod-cladding temperature and any subsequent rod bowing. Experimental data were obtained for a stress analysis of the EGCR pressure vessel. The channel entrance for the apparatus used in the study of the thermal characteristics of the EGCR fuel cluster was modified in an effort to correct for a flow maldistribution observed in earlier experiments. Circumferential temperature profiles were obtained for all seven tubes at 11 axial positions with the altered inlet configuration; the average Reynolds modulus was 50,500 and the surface heat flux was maintained at 6500 Btu/hr- ft/ sup 2./ An evaluation was completed of preliminary mass-removal measurements obtained in the study of the role of relative cluster orientation on the heat- transfer distribution in an EGCR fuel cluster. Mapping of the isothermal velocity field in the EGCR cluster was concentrated on the effect of relative cluster orientation on the velocities 0.05 in. from the rod surface at four axial levels. The measurements were restricted to a 120 ha ,n)Cu/sup 67 sector of the channel, embracing four rods. Materials Development: Work was continued in the development of a process for recovery of UC/sub 2/ by the nitrate-recycle process. Specimen pellets of UO/sub 2/ of two different grain sizes have been fabricated for use in prototype irradiation experiments. Thin plates of UC/sub 2/ and ThC/ sub 2/ were prepared for fission-gas-release experiments. The release-rate parameter for the release of Xe/sup 133/ was determined for additional grades of UO/sub 2/, including a specimen of fused oxide. Processes are being developed for the preparation of fueled graphite bodies. Graphite fueled with UC by an admixture method and fabricated into cylindrical shapes showed laminations and surface bumps due to partial oxidation of the UC during firing. The rate constants for the reaction of -60 +80-mesh UO/sub 2/ with graphite at reduced pressures were determined to be 0.18 at 1275 ha ,n)Cu/sup 67 C and 0.44 at l375 ha ,n)Cu/sup 67 C. Results indicated that the reaction rate is sensitive to particle size below about 1325 ha ,n)Cu/sup 67 C and relatively insensitive above this temperature. The elastic moduli of AGOT graphite were determined by the sonic method. On a specimen from a block prepared with needle coke, the Young's},
doi = {10.2172/4109928},
url = {https://www.osti.gov/biblio/4109928}, journal = {},
number = ,
volume = ,
place = {United States},
year = {1960},
month = {11}
}