Pressure transmitters aid nuclear safety

An ABB Automation Tech (Instrumentation + Automation) product story

Edited by the Engineeringtalk editorial team May 20, 2005

British Energy is using ABB programmable pressure transmitters for a safety-related application at its Torness nuclear power station.

British Energy has opted to use ABB programmable pressure transmitters for a safety-related application at its Torness nuclear power station.

The ABB 268 series transmitters had to meet strict internal assessment criteria to qualify for use on the power station's fuelling machine, in a SIL1 (safety integrity level 1) application.

Torness is an advanced gas-cooled reactor (AGR) power station.

The transmitters are part of a system to monitor and control the pressure of carbon dioxide coolant in the fuelling machine, which moves nuclear fuel around the reactor and central block facilities.

If the pressure of the CO2 is too low, it affects the coolant's ability to transport heat away from the fuel.

If the pressure is too high the CO2 will be too warm to provide effective cooling.

British Energy previously relied on pressure switches to play this vital role, but the switches struggled to deal with the large differential pressures involved.

They were often required to operate at atmospheric pressure on one side and 40bar(g) on the other, requiring them to be frequently recalibrated.

With a nominal operating pressure of up to 400bar and a differential pressure measuring range of 0.5mbar to 100bar, the 268 transmitter is ideal for this type of high-end process automation application.

British Energy has not experienced any of the calibration and maintenance problems associated with the old switches since the ABB transmitters were installed earlier this year.

All programmable instrumentation for use in safety-related applications in British Energy power stations must pass the company's programmable electronic system (PES) assessment, which checks that the instruments can provide the required safety integrity level.

Although British Energy's installation is a SIL1 application, ABB's 268 series transmitters have been specified because of their ability to provide the level of integrity required.

British Energy has recently completed a general assessment that should make it possible to use the ABB 268 pressure transmitters in most SIL1 applications, subject to a supplementary, application-specific assessment in each case.

As well as meeting British Energy's criteria, the ABB transmitters are designed to comply with the latest international safety standards.

Although the safety integrity levels set out in IEC61508 measure the safety function of overall systems, rather than particular instruments, the safety pressure transmitter 268 is designed to meet typical requirements for use in hazardous applications that call for SIL2 and SIL3 integrity.

The 268 pressure transmitter is part of ABB's 2600T pressure transmitter series, which offers one of the most complete ranges of pressure measurement equipment currently available.

A vast selection of options, including basic model types, materials, working pressure, fill fluids, remote seal options and communications standards, enables the 2600T series to offer a host of customisable pressure transmitter solutions for a host of applications.