Overview
The CALDON LEFM 2010RCT Reactor Coolant Average Temperature Meter is a highly reliable system that requires little maintenance and provides preventative diagnostic indicators. The system has continuous online testing that verifies operation within the specified accuracy envelope. Any detected error will generate a message on the display of the electronic unit, as well as indication via the analog and serial outputs.
Our CALDON LEFM 2010RCT Reactor Coolant Average Temperature Meter provides accurate measurement of reactor coolant system (RCS) bulk average temperatures. Two fixtures with transducers (six for the hot leg and four for the cold leg) are mounted externally to the existing piping. This eliminates any need for troublesome RTD bypass loops or alteration of existing piping and save the expensive analyses required for changes in plant design. The fixtures precisely locate the transducers on the hot and cold leg pipe surfaces to form acoustic paths. Acoustic paths are sent back and forth between transducer pairs. These transit times are used with the pipe dimensions and the acoustic properties of water to calculate the fluid bulk average temperature.
The system provides a much more accurate and reliable measurement of the bulk average temperature than can be obtained from a single-point RTD. Temperature stratification in hot legs has caused biases up to ±3° F (±1.66° C) in conventional RTD measurement, and increased uncertainty in the differential between the hot and cold leg temperatures. The higher accuracy of the CALDON LEFM 2010RCT Reactor Coolant Average Temperature Meter reduces the RCS differential temperature uncertainty to ±1° F (±0.55° C). Elimination of the RTD biases provide more margin between the calculated RCS flow and minimum flows required by the technical specification.
The CALDON LEFM 2010RCT Reactor Coolant Average Temperature Meter system consists of two electronic units, two fixtures, 10 transducers, and 10 transducer cables per loop (one hot leg and one cold leg). The electronics units have panels that display the loop temperatures and system status. Analog (4 to 20 mA) and serial (RS232) outputs are provided for data acquisition and interface to plant equipment. Optional configurations are available for hot or cold leg only measurements.
Specifications
Standard Features
- Onsite installation of fixtures and transducers
- System commissioning
- Collection of baseline design data
- Customer training
- Field testing
- Uncertainty analysis in accordance with ASME PTC 19.1
- External fixtures for hot and cold leg measurement
- Calculates fluid bulk temperature more accurately than single point RTD
- Reduces RCS ΔT uncertainty, which provides more margin between calculated RCS flow and minimum flow required by specification
