Aging of thermocouples by nuclear radiation

Technical Report · Fri Feb 28 04:00:00 EDT 1975

DOI:https://doi.org/10.2172/4947903· OSTI ID:4947903

Lucot, M.

The behavior of more than 300 stainless steel sheathed, magnesia insulated, Chromel/Alumel thermocouples irradiated in the French OSIRIS reactor for periods of 500 to 5000 hrs is reported. Failure rate statistics and causes are given. Attempts to restore failed junctions in situ by capacitor discharge were 50% successful. In-pile experiments were conducted on thermocouple errors using a Colibri type irradiation apparatus: a gamma-heated thimble in which the temperature can be controlled from 200 to 800 deg C by varying a helium-nitrogen gas mixture, and by additional electrical heating. Using this apparatus, the effect of parasitic currents and reduced electrical resistance of insulation in isolated thermocouples was studied.

• Research Organization: French Atomic Energy Commission (CEA), Gif-sur-Yvette (France). Saclay Nuclear Research Center
• Sponsoring Organization: Sponsor not identified
• NSA Number: NSA-31-011427
• OSTI ID: 4947903
• Report Number(s): ORNL-tr--2854; DPE/SPE--69-253
• Country of Publication: France
• Language: English

Related Subjects

ALUMEL
CALIBRATION
CHROMEL
ELECTRICAL INSULATION
ERRORS
FAILURES
MAGNESIUM OXIDES
N46300* --Instrumentation--Radiation Effects on Instrument Components
Instruments
or Electronic Systems
N79400 -- Reactors--Reactor Control Systems
N79400 --Reactors--Reactor Control Systems
NEUTRONS
OSIRIS REACTOR
PHYSICAL RADIATION EFFECTS
THERMOCOUPLES
TRANSMUTATION