Caldon LEFM ultrasonic MKIII nuclear flowmeter
Precision feedwater measurement for nuclear power plants
Applications
- Nuclear power plant feedwater systems
Benefits
Enables nuclear power plant operators to
- license for measurement uncertainty recapture (MUR) power uprate
- recover megawatts lost because of differential pressure meter fouling or drift
Features
- Mass flow accuracy to ±0.3% when paired with the available leading edge flowmeter (LEFM) electronics platforms at uprate flow conditions
- Rated to 500 degF [260 degC] and 2,500-psi [172-bar] gauge pressure
- Integral redundant resistance temperature detectors (RTDs) for meter body temperature
- Pressure sensing port and redundant Rosemount pressure transmitters immediately downstream of the measurement section for maximum accuracy in feedwater density calculation
- Forged from a solid block per ASTM A105, with a specified minimum chrome content to mitigate flow-accelerated corrosion (FAC)
- Ability to match any feedwater pipe sizing requirements
- Stamped ultrasonic testing (UT) measurement locations for preventive maintenance
- Welded lifting lugs
- Common manifolds for accessibility to the transducers and terminations for efficient installation and maintenance
- Transducers fully isolated from the pressure boundary and replaceable online at normal operating conditions
- Independent system testing and verification at a NIST*-traceable facility in plant-specific hydraulic piping model
* US National Institute of Standards and Technology
How it improves performance
The Caldon™ LEFM ultrasonic MKIII nuclear flowmeter is designed specifically for feedwater applications to enable nuclear power plants to license for a measurement uncertainty recapture (MUR) uprate of up to 1.7%.
The meter’s chordal transducer path configurations are based on the Gaussian integration technique, delivering optimal measurement performance. The standard configuration consists of an eight-path, dual-plane meter, enabling plants to unlock their full potential under the US Nuclear Regulatory Commission (NRC) Appendix K power uprate program. The perpendicular arrangement of the planes corrects for swirl and maintains accuracy through hydraulic profile changes, allowing installation in almost any feedwater piping configuration.
The third-generation design marked a transition from reliance on externally welded transducer housings. A forged and machined meter body with threaded housings provides improved tolerance control while additionally mitigating the potential of a weld failure at the wetted boundary. The change to internal housing manifolds results in less variability in path alignment, improving signal quality while reducing maintenance clearance requirements.
The update to the meter body design is accompanied by an upgrade to the transducers, which have been designed with a larger form factor. This allows use of a larger piezoelectric crystal and eliminates pushrods, resulting in higher coherent signal-to-noise (SNRc) ratios at lower gain values in addition to increased longevity.
