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Title: Double-clad nuclear fuel safety rod

Abstract

A device for shutting down a nuclear reactor during an undercooling or overpower event, whether or not the reactor's scram system operates properly. This is accomplished by double-clad fuel safety rods positioned at various locations throughout the reactor core, wherein melting of a secondary internal cladding of the rod allows the fuel column therein to shift from the reactor core to place the reactor in a subcritical condition.

Inventors:
 [1];  [2];  [3]
  1. (Los Altos, CA)
  2. (Cupertino, CA)
  3. (San Jose, CA)
Publication Date:
Research Org.:
GENERAL ELECTRIC CO
OSTI Identifier:
865156
Patent Number(s):
US 4470947
Assignee:
United States of America as represented by United States (Washington, DC) OSTI
DOE Contract Number:
AT03-76SF71031
Resource Type:
Patent
Country of Publication:
United States
Language:
English
Subject:
double-clad; nuclear; fuel; safety; rod; device; shutting; reactor; undercooling; overpower; event; scram; operates; properly; accomplished; rods; positioned; various; locations; throughout; core; melting; secondary; internal; cladding; allows; column; therein; shift; subcritical; condition; safety rod; nuclear fuel; nuclear reactor; reactor core; various locations; fuel safety; clad fuel; clad nuclear; /376/976/

Citation Formats

McCarthy, William H., Atcheson, Donald B., and Vaidyanathan, Swaminathan. Double-clad nuclear fuel safety rod. United States: N. p., 1984. Web.
McCarthy, William H., Atcheson, Donald B., & Vaidyanathan, Swaminathan. Double-clad nuclear fuel safety rod. United States.
McCarthy, William H., Atcheson, Donald B., and Vaidyanathan, Swaminathan. Sun . "Double-clad nuclear fuel safety rod". United States. doi:. https://www.osti.gov/servlets/purl/865156.
@article{osti_865156,
title = {Double-clad nuclear fuel safety rod},
author = {McCarthy, William H. and Atcheson, Donald B. and Vaidyanathan, Swaminathan},
abstractNote = {A device for shutting down a nuclear reactor during an undercooling or overpower event, whether or not the reactor's scram system operates properly. This is accomplished by double-clad fuel safety rods positioned at various locations throughout the reactor core, wherein melting of a secondary internal cladding of the rod allows the fuel column therein to shift from the reactor core to place the reactor in a subcritical condition.},
doi = {},
journal = {},
number = ,
volume = ,
place = {United States},
year = {Sun Jan 01 00:00:00 EST 1984},
month = {Sun Jan 01 00:00:00 EST 1984}
}

Patent:

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  • A device for shutting down a nuclear reactor during an undercooling or overpower event, whether or not the reactor's scram system operates properly. This is accomplished by double-clad fuel safety rods positioned at various locations throughout the reactor core, wherein melting of a secondary internal cladding of the rod allows the fuel column therein to shift from the reactor core to place the reactor in a subcritical condition.
  • A device for shutting down a nuclear reactor during an undercooling or overpower event, whether or not the reactor's scram system operates properly. This is accomplished by double-clad fuel safety rods positioned at various locations throughout the reactor core, wherein melting of a secondary internal cladding of the rod allows the fuel column therein to shift from the reactor core to place the reactor in a subcritical condition.
  • This patent describes a nuclear fuel rod comprising a metallic tubular cladding containing nuclear fuel pellets, the pellets containing enriched uranium-235. The improvement described here comprises: ceramic wafers, each wafter comprising a sintered mixture of gadolinium oxide and uranium dioxide, the uranium oxide having no more uranium-235 than is present in natural uranium dioxide. Each of the wafers is axially disposed between a major portion of adjacent the nuclear fuel pellets, whereby the wafers freeze out volatile fission products produced by the nuclear fuel and prevent interaction of the fission products with the metallic tubing cladding.
  • A method is disclosed for testing the clad integrity of a nuclear fuel rod, comprising the first step of fabricating a sealed fuel rod with a wad of electrically conducting material mounted therein. The material is of a type that undergoes a permanent change in electrical conductivity when exposed to water. The next step is to establish an eddy current signal characteristic of the moisture-free rod. The rod is then loaded into the core as part of a fuel assembly. After the producing power, the assembly is removed for inspection, and an eddy current signal is again obtained from themore » rod. The eddy current signals are compared to determine whether inleakage of moisture has oxidized or otherwise altered the conductivity of the wad enough to significantly change the characteristic signal.« less
  • A method of joining fuel rod end caps and cladding tubes by resistance pressure welding within a welding chamber is described. A welding device is brought into engagement with an end portion of a rigidly mounted cladding tube. An opening chuck as well as a divided welding electrode, both of which are mounted at one side of the welding chamber, are shifted along a predetermined length of the cladding tube end portion. The chuck and the divided welding electrode are brought into contact with the cladding tube end portion. Another welding electrode carrying an end cap is thrust into themore » welding chamber from the other side thereof so that the end cap is fed to the open end of the cladding tube end portion. The welding chamber is sealed by sealing members sealingly engaging the cladding tube end portion and the other welding electrode and then the interior of the welding chamber is evacuated and filled with protective gas. The end cap is pressed onto the open end of the cladding tube end portion. A welding current is passed through the welding electrodes so as to weld the end cap to the end of the cladding tube end portion.« less