Title :
Brazing refractory metals used in high-temperature nuclear instrumentation
Author :
Palmer, A.J. ; Woolstenhulme, C.J.
Author_Institution :
Idaho Nat. Lab., Idaho Falls, ID, USA
Abstract :
As part of the U. S. Department of Energy (DOE)-sponsored Next Generation Nuclear Project (NGNP) currently ongoing at Idaho National Laboratory (INL), the irradiation performance of candidate high-temperature gas reactor fuels and materials is being evaluated at INL´s Advanced Test Reactor (ATR). The design of the first Advanced Gas Reactor (AGR-1) TRISO fuel experiment, currently being irradiated in the ATR, required development of special techniques for brazing niobium and molybdenum. Brazing is one technique used to join refractory metals to each other and to stainless steel alloys. Although brazing processes are well established, it is difficult to braze niobium, molybdenum, and most other refractory metals because they quickly develop adherent oxides when exposed to room-temperature air. Specialized techniques and methods were developed by INL to overcome these obstacles. This paper describes the techniques developed for removing these oxides, as well as the ASME Section IX-qualified braze procedures that were developed as part of the AGR-1 project. All brazes were made using an induction coil with an inert or reducing atmosphere at low pressure. Other parameters, such as filler metals, fluxes used, and general setup procedures, are also discussed.
Keywords :
brazing; fission reactor materials; fission research reactors; molybdenum; niobium; nuclear instrumentation; refractories; stainless steel; AGR-1 TRISO fuel experiment; ASME Section IX-qualified braze procedure; Advanced Gas Reactor; Advanced Test Reactor; Idaho National Laboratory; Next Generation Nuclear Project; US Department of Energy; filler metals; fission reactor design; fission reactor materials; high-temperature gas reactor fuels; high-temperature nuclear instrumentation; molybdenum; niobium; refractory metal brazing; stainless steel alloys; Coils; Fuels; Inductors; Instruments; Iron alloys; Laboratories; Materials testing; Niobium; Reactor instrumentation; Steel; high-temperature irradiation; induction brazing; refractory metal brazing; stainless steel alloys;
Conference_Titel :
Advancements in Nuclear Instrumentation Measurement Methods and their Applications (ANIMMA), 2009 First International Conference on
Conference_Location :
Marseille
Print_ISBN :
978-1-4244-5207-1
Electronic_ISBN :
978-1-4244-5208-8
DOI :
10.1109/ANIMMA.2009.5503815