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Title: BONUS ZERO POWER CRITICAL EXPERIMENTS AND APPLICATION TO THE REACTOR DESIGN. Terminal Report

Abstract

An extensive program of full-scale critical experiments was conducted to investigate the physics characteristics of nuclear mockups of the BONUS reactor. The nuclear mockups studied were a cold-clean mockup and a simulated hotoperating mockup. The cold-clean BONUS mockup was precise except for the substitution of aluminum for Zircaloy-2, a 65/8-inch deficiency in core height in the mockup, and some differences in fuel enrichments. The hot-operating BONUS reactor was simulated by positioning aluminum rods and sheets within the active core regions so as to duplicate the reduced water density in the actual BONUS reactor; the uniform water-density reduction due to temperature and the axially nonuniform reduction due to steam formation in the boiler were simulated. The shims consisted of part-length poison elements placed in the central water holes of some of the boiler fuel boxes (each box contained a 6 x 6 square array of fuel rods with the four central rods missing to form the water hole), and strip-type shims positioned in the water gap between the boiler and the superheater regions. As a result of the cold-clean critical experiments, data were obtained on critical control-rod configurations and reactivity worths, shutdown margins. uniform temperature coefficients and superheater flooding coefficients; themore » worths of the poison shims and of the enriched fuel in a centrally-located boiler fuel box were also determined. For the simulated hot-operating condition, data were obtained on critical control rod configurations and reactivity worths, and superheater flooding coefficients; in addition, numerous experiments were conducted to map the spatial power distributions corresponding to the various controlrod configurations of interest. The effects of modifications in the shim loading were investigated for both the cold-clean and the simulated hot-operating mockups. Experimental measurements were made on a variety of arrays of boiler fuel boxes; the measurements consisted of determinations of criticality in terms of partial water height and rod-bank position, and the change in reactivity with partial water height. In some of the experiments, boron-polyethylene shims were inserted in the central water hole of each boiler fuel box of a given array to obtain a systematic study of their effect on criticality. Because of the basic differences existing between the BONUS hot-simulated critical assembly and the actual BONUS reactor design, the experimental data are not in every case directly applicable to the BONUS reactor design. In order to permit reliable extrapolation of these data to the BONUS reactor design, an analytical procedure was developed for calculating the important features of the spatial power distributions in the simulated hot-operating critical reactor; for these calculations the control-rod configurations were limited to patterns which preserve symmetry of the power distribution in any octant of the core in any horizontal plane through the reactor. The analytical procedure was checked by a comparison of the calculated data with the experimental data obtained on the hotsimulated mockup. The agreement between calculated and experimental results is good, permitting application of the derived calculational methods to the actual BONUS reactor design. (auth)« less

Publication Date:
Research Org.:
General Nuclear Engineering Corp., Dunedin, Fla.
OSTI Identifier:
4828649
Report Number(s):
GNEC-198
NSA Number:
NSA-16-024981
DOE Contract Number:  
AT(40-1)-2674
Resource Type:
Technical Report
Resource Relation:
Other Information: Orig. Receipt Date: 31-DEC-62
Country of Publication:
United States
Language:
English
Subject:
REACTOR TECHNOLOGY; ALUMINUM; ANALOG SYSTEMS; BOILING; BONUS; CONFIGURATION; CONTROL ELEMENTS; CRITICAL ASSEMBLIES; CRITICALITY; DENSITY; DISTRIBUTION; ENRICHMENT; EQUATIONS; ERRORS; FLUID FLOW; MEASURED VALUES; MOCKUP; NEUTRON FLUX; PLANNING; POWER; POWER PLANTS; REACTIVITY; REACTOR CORE; REACTORS; SUPERHEATING; TEMPERATURE; VARIATIONS; WATER COOLANT; WATER MODERATOR; ZIRCALOY; ZONES

Citation Formats

. BONUS ZERO POWER CRITICAL EXPERIMENTS AND APPLICATION TO THE REACTOR DESIGN. Terminal Report. United States: N. p., 1962. Web.
. BONUS ZERO POWER CRITICAL EXPERIMENTS AND APPLICATION TO THE REACTOR DESIGN. Terminal Report. United States.
. Sat . "BONUS ZERO POWER CRITICAL EXPERIMENTS AND APPLICATION TO THE REACTOR DESIGN. Terminal Report". United States.
@article{osti_4828649,
title = {BONUS ZERO POWER CRITICAL EXPERIMENTS AND APPLICATION TO THE REACTOR DESIGN. Terminal Report},
author = {},
abstractNote = {An extensive program of full-scale critical experiments was conducted to investigate the physics characteristics of nuclear mockups of the BONUS reactor. The nuclear mockups studied were a cold-clean mockup and a simulated hotoperating mockup. The cold-clean BONUS mockup was precise except for the substitution of aluminum for Zircaloy-2, a 65/8-inch deficiency in core height in the mockup, and some differences in fuel enrichments. The hot-operating BONUS reactor was simulated by positioning aluminum rods and sheets within the active core regions so as to duplicate the reduced water density in the actual BONUS reactor; the uniform water-density reduction due to temperature and the axially nonuniform reduction due to steam formation in the boiler were simulated. The shims consisted of part-length poison elements placed in the central water holes of some of the boiler fuel boxes (each box contained a 6 x 6 square array of fuel rods with the four central rods missing to form the water hole), and strip-type shims positioned in the water gap between the boiler and the superheater regions. As a result of the cold-clean critical experiments, data were obtained on critical control-rod configurations and reactivity worths, shutdown margins. uniform temperature coefficients and superheater flooding coefficients; the worths of the poison shims and of the enriched fuel in a centrally-located boiler fuel box were also determined. For the simulated hot-operating condition, data were obtained on critical control rod configurations and reactivity worths, and superheater flooding coefficients; in addition, numerous experiments were conducted to map the spatial power distributions corresponding to the various controlrod configurations of interest. The effects of modifications in the shim loading were investigated for both the cold-clean and the simulated hot-operating mockups. Experimental measurements were made on a variety of arrays of boiler fuel boxes; the measurements consisted of determinations of criticality in terms of partial water height and rod-bank position, and the change in reactivity with partial water height. In some of the experiments, boron-polyethylene shims were inserted in the central water hole of each boiler fuel box of a given array to obtain a systematic study of their effect on criticality. Because of the basic differences existing between the BONUS hot-simulated critical assembly and the actual BONUS reactor design, the experimental data are not in every case directly applicable to the BONUS reactor design. In order to permit reliable extrapolation of these data to the BONUS reactor design, an analytical procedure was developed for calculating the important features of the spatial power distributions in the simulated hot-operating critical reactor; for these calculations the control-rod configurations were limited to patterns which preserve symmetry of the power distribution in any octant of the core in any horizontal plane through the reactor. The analytical procedure was checked by a comparison of the calculated data with the experimental data obtained on the hotsimulated mockup. The agreement between calculated and experimental results is good, permitting application of the derived calculational methods to the actual BONUS reactor design. (auth)},
doi = {},
url = {https://www.osti.gov/biblio/4828649}, journal = {},
number = ,
volume = ,
place = {United States},
year = {1962},
month = {2}
}

Technical Report:
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