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Title: LOFT reactor vessel head instrument penetration, flange thermal analysis

Abstract

A redesign of the LOFT instrument penetration necessitated a reanalysis of the thermal conditions existing in the nozzle and flange during a Loss of Coolant Experiment (LOCE). The maximum temperature gradient existing in the instrument flange will be used to determine the thermal stresses and maximum number of allowable cycles for the instrument flange. Based upon the specification and thermal conditions predicted by RELAP4/MOD5, the maximum temperature gradient through the flange will not exceed 216/sup 0/F. The thermal conditions predicted by RELAP4/MOD2 for the nozzle head penetration assembly were less severe than those used in the original thermal-stress analysis, so only the flange was analyzed here. If the thermal stresses are marginal with the 216/sup 0/F ..delta..T, a more detailed analysis should be done as the heat slab model used in RELAP is only one dimensional. Conservative hand calculations were performed for a heatup rate of 100/sup 0/F per hour and it was determined that the worst temperature gradient through the flange will be less than 81/sup 0/F.

Authors:
Publication Date:
Research Org.:
Idaho National Engineering Lab., Idaho Falls (USA)
OSTI Identifier:
6703251
Report Number(s):
LTR-1119-37; RE-A-78-028
TRN: 78-016168
DOE Contract Number:  
EY-76-C-07-1570
Resource Type:
Technical Report
Resource Relation:
Other Information: Portions of document are illegible
Country of Publication:
United States
Language:
English
Subject:
21 SPECIFIC NUCLEAR REACTORS AND ASSOCIATED PLANTS; LOFT REACTOR; PRESSURE VESSELS; NOZZLES; REACTOR INSTRUMENTATION; TEMPERATURE GRADIENTS; THERMAL STRESSES; CONTAINERS; PWR TYPE REACTORS; REACTORS; RESEARCH AND TEST REACTORS; STRESSES; TANK TYPE REACTORS; TEST REACTORS; WATER COOLED REACTORS; WATER MODERATED REACTORS; 220600* - Nuclear Reactor Technology- Research, Test & Experimental Reactors

Citation Formats

Howell, S. K.. LOFT reactor vessel head instrument penetration, flange thermal analysis. United States: N. p., 1978. Web. doi:10.2172/6703251.
Howell, S. K.. LOFT reactor vessel head instrument penetration, flange thermal analysis. United States. https://doi.org/10.2172/6703251
Howell, S. K.. Fri . "LOFT reactor vessel head instrument penetration, flange thermal analysis". United States. https://doi.org/10.2172/6703251. https://www.osti.gov/servlets/purl/6703251.
@article{osti_6703251,
title = {LOFT reactor vessel head instrument penetration, flange thermal analysis},
author = {Howell, S. K.},
abstractNote = {A redesign of the LOFT instrument penetration necessitated a reanalysis of the thermal conditions existing in the nozzle and flange during a Loss of Coolant Experiment (LOCE). The maximum temperature gradient existing in the instrument flange will be used to determine the thermal stresses and maximum number of allowable cycles for the instrument flange. Based upon the specification and thermal conditions predicted by RELAP4/MOD5, the maximum temperature gradient through the flange will not exceed 216/sup 0/F. The thermal conditions predicted by RELAP4/MOD2 for the nozzle head penetration assembly were less severe than those used in the original thermal-stress analysis, so only the flange was analyzed here. If the thermal stresses are marginal with the 216/sup 0/F ..delta..T, a more detailed analysis should be done as the heat slab model used in RELAP is only one dimensional. Conservative hand calculations were performed for a heatup rate of 100/sup 0/F per hour and it was determined that the worst temperature gradient through the flange will be less than 81/sup 0/F.},
doi = {10.2172/6703251},
url = {https://www.osti.gov/biblio/6703251}, journal = {},
number = ,
volume = ,
place = {United States},
year = {1978},
month = {5}
}