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Assessing braze quality in the actively cooled Tore Supra phase III outboard pump limiter

Conference ·
OSTI ID:196988
; ;  [1]
  1. Sandia National Lab., Albuquerque, NM (United States); and others

This paper discusses the assessment of quality of brazing of pyrolytic graphite (PG) armor brazed to copper tubes in Tore Supra`s Phase III Outboard Pump Limiter (OPL). The limiter head is a bank of 14 water-cooled copper tubes with several hundred brazed PG tiles. Braze quality was first assessed through pre-service qualification testing of individual copper/tiles assemblies. The quality of brazes was evaluated using (non-destructive) transient heating ({open_quotes}hot water{close_quotes}) tests performed in the high temperature, high pressure flow loop at Sandia`s Plasma Materials Test Facility. The surface temperatures of tiles were monitored with an infra-red (IR) camera as water at 120{degrees}C water at about 2.07 MPa (300 psi) passed through a tube assembly initially at 30{degrees}C. For tiles with braze voids or cracks, the surface temperatures lagged behind those of adjacent well bonded tiles. Temperature lags were correlated with flaw sizes observed during repairs using a detailed 2-D heat transfer analyses. {open_quotes}Bad{close_quotes} tiles, i.e., temperature lags of 10-20{degrees}C depending upon tile`s size, were easy to detect and, when removed, revealed braze voids of roughly 50% of the joint area. 11 of the 14 tubes were rebrazed after bad tiles were detected and removed. Three tubes were re-brazed twice.

Research Organization:
Sandia National Laboratory
DOE Contract Number:
AC04-94AL85000
OSTI ID:
196988
Report Number(s):
CONF-940664--
Country of Publication:
United States
Language:
English