Nuclear feedwater

Your path to an efficient power uprate


The CALDON LEFM CheckPlus™ ultrasonic feedwater flow measurement system will reduce feedwater flow uncertainty to less than 0.3% of the true flow rate, compared to a typical industry allowance of 2% uncertainty for existing feedwater measurement devices.

That’s a 6.5x increase in accuracy, opening the door to produce more power, making it safer than before and reducing the possibility of being fined for an over-power event.

With an over 20-year track record of reliability and success, this measurement system typically pays for itself in less than 18 months.

If every US plant were to increase output by the 1.7% that the CALDON LEFM CheckPlus™ system enables, it would equate to two new 850MW power plants.

  • Approved for a 1.7% power uprate by the US NRC and other international regulators.
  • Enables increased revenue with minimal equipment modifications.
  • Reaches ROI in just 18 months.
  • More accurate measurement of feedwater flow which improves plant safety and eliminates overpower events.
  • Online monitoring of the flow profile improves traceability back to the meter calibration.
  • Real-time, online verification for improved reliability.
  • A unique 8-path concept makes the flow measurement insensitive by hydraulic changes in-situ.
  • Capable of assisting root cause analysis and meeting PTC-6 standard.

Understanding the MUR concept


Power Uprate gives your plant the ability to generate additional capacity and improve economic performance. MUR (Measurement of Uncertainty Recapture) – pioneered by CALDON for over 25 years – is one of the most efficient ways to achieve this goal.


The CALDON LEFM CheckPlus™ ultrasonic flow meter accurately measures feedwater flow within 0.3% – against a typical inaccuracy of 2% – which provides for a more accurate determination of core thermal power.

Increasing your licensed power level by decreasing power uncertainty

MUR credentials

The first CALDON LEFM (Leading Edge Flow Measurement) specifically for Power Uprate in nuclear power plants was launched in 1997, and in the 24 years since has built a phenomenal list of credentials with benefits across the industry. This technology enables nuclear power plant owners to provide reliable, verifiable information to regulators, as well as increasing revenue, efficiency and safety.

  • 74 Number of approved MUR amendments to licenses by US, Spain, and Taiwan.
  • 1,106 Total increase in MWt/MWe due to MUR.
  • 800+ Cumulative years of operation in nuclear feedwater.

The complete solution for existing plants

CALDON LEFM CheckPlus system is approved by the US NRC and other international regulators as the basis for a proven, verifiable measurement system for MUR uprates.

With our experienced support, the CALDON LEFM CheckPlus system can be installed within an outage, during standard maintenance or refueling, which means there is little or no interruption to your service.

Omni Surveillance for Lift is part of our growing portfolio of surveillance applications and will be continuously updated with new Sensia surveillance applications and deeper analytics, to ensure it continues to meet your needs.

The complete solution for new plants

In new plants, the CALDON LEFM CheckPlus flow measurement system can completely replace existing technologies and deliver not just OPEX savings, but reduced CAPEX and provide a much faster ROI.

Firstly, we can optimize the piping to the system so that only a limited set of hydraulic testing is needed, which means you can eliminate the need for special piping layouts and valves typically required for other flow meter technologies from your construction costs.

Secondly, CALDON LEFM CheckPlus system meets the mass flow measurement requirements of ASME Performance Test Code 6 (PTC-6) without modifications. This CAPEX benefits then extends into further OPEX saving by enabling continuous monitoring of the power conversion system for the life of your plant.

Maximize accuracy

The CALDON LEFM CheckPlus feedwater flow measurement system uses proven ultrasonic transit-time technology for the highest accuracy measurements, regardless of upstream hydraulic conditions and other parameters that could impact performance.

Verifiable performance

Our continuous self-checking circuitry ensures that you are able to verify performance online, either at the meter through an intuitive touchscreen display or remotely on the plant’s process computer. The system will notify you of its overall health and online performance with both real-time data and historical trending. The LEFM CheckPlus system also provides predictive indicators of the system’s health which allows for maintenance to be performed when most convenient for plant operations. The self-verification means you can be confident of avoiding over-power events and fines.

System verification before and during use

Your installation will be independently tested and verified at Alden Laboratories using plant specific. hydraulic piping models. Once installed, our software offers continuous online diagnostics.

High-quality engineering

Our flowmeters are a fully welded design, with sixteen integrated transducer housings that allows for online transducer maintenance that does not break the pressure boundary

Sensia support

Sensia is the unification of sensing, intelligence and action, bringing together the best of the best: the pioneering process automation, real-time control and IoT technologies of Rockwell Automation, combined with the unmatched measurement and instrumentation, software and analytics capabilities of Schlumberger.

We use our cumulative operating experience to provide comprehensive and valuable support, including:

  • Maintenance and Monitoring program with monthly evaluations and LEFM reports
  • Support for your licensing applications and regulatory information and approvals
  • Start-up commissioning and testing
  • Ongoing field support with local agents

For more information please contact us

Your details
Areas of interest (tick all that apply)
Please indicate your region
Enter security code:
 Security code