Electric heater for nuclear fuel rod simulators

Patent · 01 January 1982

OSTI ID:864185

McCulloch, Reginald W ^[1]; Dial, Ralph E ^[2]

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1. Knoxville, TN
2. Concord, TN

The present invention is directed to an electric cartridge-type heater for use as a simulator for a nuclear fuel pin in reactor studies. The heater comprises an elongated cylindrical housing containing a longitudinally extending helically wound heating element with the heating element radially inwardly separated from the housing. Crushed cold-pressed preforms of boron nitride electrically insulate the heating element from the housing while providing good thermal conductivity. Crushed cold-pressed preforms of magnesia or a magnesia-15 percent boron nitride mixture are disposed in the cavity of the helical heating element. The coefficient of thermal expansion of the magnesia or the magnesia-boron nitride mixture is higher than that of the boron nitride disposed about the heating element for urging the boron nitride radially outwardly against the housing during elevated temperatures to assure adequate thermal contact between the housing and the boron nitride.

• Research Organization: Oak Ridge National Laboratory (ORNL), Oak Ridge, TN
• Assignee: United States of America as represented by United States (Washington, DC)
• Patent Number(s): US 4326122
• OSTI ID: 864185
• Country of Publication: United States
• Language: English

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/219/29/338/376/976/
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cold-pressed
comprises
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contact
containing
crushed
cylindrical
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directed
disposed
electric
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electrically insulate
element
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elongated
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fuel
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helical
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magnesia
magnesia-15
magnesia-boron
mixture
nitride
nuclear
nuclear fuel
outwardly
percent
percent boron
preforms
providing
radially
radially inward
radially inwardly
radially outward
radially outwardly
reactor
reactor studies
rod
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simulator
simulators
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temperatures
thermal
thermal conductivity
thermal contact
thermal expansion
type heat
urging
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