Many of the Meggitt systems that have been delivered were to replace existing systems. A good indication of how Meggitt systems perform relative to systems supplied by others may be derived from those customers in particular. A question was posed to one such user as follows:
“How do operating costs compare before and after installation of the Meggitt system?”
“I looked at the maintenance costs for the new analyzer verses the old analyzer. I can safely say that we spent about $200,000 less this past year on the analyzers than we did in 1999, the year for which I tracked all of the maintenance costs. Arguably, 1999 might be a worst case scenario but the other years weren’t much better!”
A second example was from a BWR plant concerning a dual gas (hydrogen and oxygen off-gas monitoring system. The communication was an email that was sent to other members of a BWR User’s group and concerned the system's performance during the first year.
“I think that the currently installed monitors at (Plant Name omitted) are by far superior to any other hydrogen or oxygen cell any of the off gas system engineers have reported on. I am not biased on this issue. I have cut my corrective work orders down on the analyzers to just 2 per year for minor analyzer issues. ------ I used to get several Condition Reports per month and several Apparent Cause Evaluations per year on the old analyzers. I have not gotten one report over the past 16 months! ---- Our IM department is extremely satisfied with the current Meggitt Safety System Analyzers.”
A utility supplied the automatic calibration results accumulated on one of their CAMS Divisions during 24 months of operation, Figure 1. The parameter was the “As Left” Slope. This data was used to determine the equivalent drift of each analyzer during the 24 month period. The equivalent uncertainty @ 4% Concentration was ±0.12% Hydrogen and ±0.16% Oxygen.
Long Term Hydrogen Sensor Performance
The first 16 containment atmosphere monitoring system hydrogen sensors were supplied for INSITU installations (Sensors installed in containment). The sensors operated continuously for a minimum of 8 years with some sensors in service as long as 10 years prior to scheduled replacement.