British Energy – Heysham II | Alfa Laval

Reliability at the core

Heysham II is a nuclear power station owned and operated by British Energy, and located just outside the port of Heysham. The plant’s two advanced gas-cooled reactors (AGRs) provide steam to two 660 MW steam turbines.

DATE 2022-05-12

Heysham II is a nuclear power station owned and operated by British Energy, and located just outside the port of Heysham. The plant’s two advanced gascooled reactors (AGRs) provide steam to two 660 MW steam turbines.

Prior to privatization, British Energy was part of the Central Electricity Generating Board (CEGB), an organization with a worldwide reputation for excellence. The power station provides electricity to the highvoltage electricity transmission network for distribution throughout the UK.

Heysham PowerPlant ALF filters inside 640x438.jpg

A new stable sea filter alternative

After many years of power generation, the conventional screening and filtering systems installed during the construction phase of Heysham II needed replacing due to their deteriorating performance. To improve reliability and availability, British Energy sought alternative solutions to the seawater filtration system used in the reactor cooling process.

The original seawater filters at Heysham II were susceptible to clogging, and the service life of the original plant was coming to an end. Recognizing the need for increased availability and reliability, as well as reduced maintenance, the station staff investigated replacing the conventional basket filters with alternative filter types.

Following thorough investigation into the filters available, British Energy purchased Alfa Laval Filters (ALF) for installation during the plant outages of 2001 and 2002.

Basically, we had experienced a lot of problems with the original strainers. So when we looked at replacements, we were mainly interested in reliability. We were looking for very tight delivery times and these were actually specified in the contract. Alfa Laval reacted to the urgency of the situation and came up with the goods when we needed them.” - Mike Craddock of British Energy

The Heysham plant’s seawater filtration system uses water from Morecambe Bay. However, the bay is relatively shallow and sandy, which means the filtration system has to remove sand as well as marine life and shell debris.

Alfa Laval Filters (ALF) are located in the reactor containment building, mounted horizontally in the seawater piping system, after the coarse drum screen and ahead of the cooling water pumps. The filters effectively remove particulate down to 1.5 mm in size.

Reliable efficiency improvements

The Alfa Laval Filters (ALF) have improved both reliability and efficiency. The automatic flushing, based on a timer and pressure differential, ensures the filters are kept free of debris.

There is little doubt that we have seen a great improvement in efficiency since installing the Alfa Laval seawater filters. - Mike Craddock of British Energy
Alf Complete filter

About ALF filter

The Alfa Laval Filter is a pressure filter with an automatic flushing arrangement. ALF filters can be installed in almost any position, horizontally or vertically thanks to the flexible nozzle orientation and because the automatic regeneration process is run by the inlet pressure. The filter is divided into two sections by the flow diverter valve, the inlet section, and the outlet section. A flushing valve for discharging the debris is located at the end of the outlet section.

 ALF filter

Equipment supplied

4 x ALF40-R – May 2001
4 x ALF40-R – April 2002


  • Pressure Vessel Code BS5500
  • Body: carbon steel (rubber lined)
  • Filter basket: AISI316
  • Filter mesh:  1.5 mm (0.06 inch) -  2.33 mm (0.092 inch)
  • Seawater flow: 1260 m3/hr/filter (5,548 GPM)
  • Design pressure: 10 barg
  • Design temperature: 65°C / 149°F
  • Horizontal mounting
  • Pneumatic control


Increased production

Efficiency improvements with Alfa Laval seawater filters.