A nuclear power station in Washington, USA, recently purchased a portable hydrogen analyser from H2scan for the detection of hydrogen during a cask storage welding process. The analyser is able to provide immediate indication of any hydrogen leak and as such represents a vital component of the plant’s safety strategy.
The analyser, a HY-ALERTA™ 500 is highly sensitive to hydrogen and provides an almost instantaneous warning of any hydrogen leak with a unique visual LED array on the sensor probe. Readings are taken every 10 minutes for the duration of the lid to shell welding process, which typically takes 14 hours.
As a result of a recent procedural change, nuclear facilities are required to purge with an inert gas during welding operations and argon is used during the cask welding process. Importantly, the HY-ALERTA™ 500 is unaffected by argon; it does not require oxygen to operate and is able to function correctly in a wide variety of environmental conditions.
With two sensing elements on the same semiconductor die, the HY-ALERTA™ 500 can detect hydrogen leaks as low as 15 ppm and will not saturate or be destroyed when detecting high concentrations of hydrogen up to 100%. The solid-state sensor does not incorporate any consumables or moving parts and provides a 10 year expected lifespan.
Explaining the advantages of being able to monitor for hydrogen without oxygen, the power station supervisor of reactor maintenance, said "H2scan’s HY-ALERTA™ 500 was very reliable, easy to use, and improved our cask welding process. Without this instrument it would not be possible to detect a hydrogen build up during the cask welding process. A flash or burn-through is not only dangerous; it would cause a stoppage of the entire facility.
"Implementing H2scan’s analyser allowed operators to closely monitor the hydrogen concentration in real-time and halt the welding process if hydrogen was present."