Radiological Surveillance Systems


Omniflex wins NDA Award for Innovation.... Read the press release....

Omniflex has over 20 years experience in the design and supply of radiological surveillance and protection systems across Nuclear sites and PET (Positron Emission Tomography) Hospitals and Facilities.
Read more about our history....

Nuclear Reactor
  • Building and Site-wide Surveillance, protection and evacuation systems
  • Nulcear Site Perimeter Monitoring providing essential warnings to emergency teams
  • Interface to any radiation monitor and SCADA/DCS for maximum flexibility
  • PET (Positron Emission Tomography) Facilities Monitoring to increase personnel safety and meet environmental emissions legislation
  • IEC61508 SIL2 Radiation Door Warning Signs to increase Personnel Safety
  • industry Standard IEC61508 Emphasis assessed alarm monitoring systems.

Nuclear Radiological Surveillance

Omniflex is the market leader in providing radiological surveillance and protection systems across many of the UK's Nuclear sites.

Omniflex systems interface to all makes and types of radiation monitors, enabling site personal to monitor the entire facility on an integrated SCADA/DCS system.

Omniflex also provides independent IEC61508 Alarm Annunciator systems which have been assessed and approved through the EMPHASIS program.

Read more on RSS...

Nuclear Perimeter Monitoring

Nuclear Site Perimeter Monitoring Systems, are also known as EPGMS (Emergency Plume Gamma Monitoring Systems).

The primary function of the EPGMS is to provide essential information to the emergency team on site to assist in the assessment of the local population's radiation dose following an accidental release of radioactivity from the site.

These systems interface with meteorological systems to monitor wind speed, direction and humidity.

Read more on EPGMS...

Interface to any Monitor

Omniflex have developed interfaces to most 3rd party manufacturer's radiation monitors. This provides customers with the choice and flexibility of monitors they choose to use across the site and allows them all to be monitored on the same system.

This can extend the life span and functionality of obsolete and legacy monitors as these can also be included in the new monitoring system.

With the flexible networking capability and interfacing to all types of SCADA/DCS systems, our customers have total flexibility and control of the type of monitoring system they choose.

PET Facilities Monitoring

Omniflex's Radiological Monitoring and Protection Systems have been used extensively throughout the UK in PET Facilities. These systems provide radiation monitoring and protection across their isotope production (Cyclotron and Hot Cells) and patient monitoring / care areas throughout the facilities.

Omniflex has formed associations with key strategic industry partners to be able to provide fully networked systems with bespoke control options to meet regulatory standards and operate safely.

Monitoring includes survey monitors, installed neutron and gamma dose rate, positron sensitive detectors and gaseous/particulate for stack/duct or room air monitoring, cyclotron and hot cell door interlocking etc.

Download PET Brochure

SIL2 Door Warning Signs

Door warning signs and slave alarm units designed to meet IEC61508 SIL2 offer a visual & audible warning to safeguard against personnel inadvertently entering plant areas where hazardous or dangerous conditions are present.

Safety and EMPHASIS

The hardwired alarm annunciator is an important tool in today's environment to achieve safety objectives.

Omniflex hardwired Alarm Annunciators have been independently assessed by the following companies and establishments:

  • EMPHASIS as adopted by the Nuclear Industry Smart Instruments working group (NISIWG)
  • Evaluation International
  • TUV

Read the EMPHASIS Case Study

To find out more about our radiological s solutions: Download White Paper


Over the last 20 years Omniflex has designed and delivered hundreds of products and systems to the Nuclear Industry specialising in Alarm Annunciators, Alarm/Event Management systems, Multiplexers, and Radiological Surveillance and Protections Systems.

As part of the original British Nuclear Fuels Limited's ILW design standards, Omniflex was chosen to supply both radiological surveillance and real time alarm/event management systems. A number of interface modules and proven protocols have been specifically developed for the well proven Maxiflex I/O and Teleterm M2 systems to provide interfaces to any of the existing or future ranges of Harwell, Berthold, and Lab Impex Alpha, Beta and Gamma radiation monitors.


The original ILW design also included the supply of independent real time alarm management systems based upon the Maxilarm and Omni 4000 products.

Both these products are designed to provide real-time alarm/event monitoring, where the time stamping of the alarm is done at the front end I/O to a resolution of down to sub 1 millisecond.

Built upon the success of the work already carried out within the Nuclear Industry, Omniflex technology was chosen to implement radiological surveillance systems, critical monitoring systems and control and logging systems to PET (Positron Emission tomography) Centres across a number of hospitals, universities and Isotope manufactures within the UK.

What is an RSS System?

There are normally four elements in an RSS systems: the operator interface, the surveillance system, the building evacuation system and the hardwired alarm system.

Omniflex Engineers have vast experience in the design and configuration of various operator interfaces which include Omniflex's Omni 4000 PC based Alarm Package and various SCADA systems using most of the world's leading brands of SCADA software (such as InTouch, Factory Talk, iFix, Adroit and Panorama).

OPC Servers and other open industry standard interfaces are available for integrating the Maxiflex system to a wide range of third party Supervisory Systems. SCADA solutions are designed to provide a complete building or site-wide overview of every monitor. This enables an operator to keep an overview of the entire system, but to quickly zoom through the individual buildings and rooms down to individual monitors, all from the central control point.

Omniflex's Maxiflex RSS system is designed to provide a cost effective and extremely flexible means of interfacing any radiation monitor to the building or site-wide SCADA system. Maxiflex RSS is modular and can accommodate any type of digital, analogue, serial (point to point and multidrop), and high speed pulse inputs, together with distributed intelligent communications modules.

The Maxiflex radiation monitor Network Interface Modules (NIM's) makes it an ideal system to distribute around the building or site. Maxiflex has a very powerful communications infrastructure supporting Conet internetworking technology. A mix of communications media may be applied to suit the site including Conet/c (any grade of 2 core cable up to 10kms without the need for repeaters), Modbus, Ethernet, PSTN and Radio.

This range of specially developed Radiological Monitor interfaces allow existing infrastructure to be reliably and cost effectively networked.

The Maxiflex evacuation logic system interfaces to the RSS network. All alarms are monitored on the entire system from both the hardwired alarms from the monitors as well as the alarms generated within the SCADA system for verification. The Maxiflex evacuation node then drives volt free relay outputs depending on the % of standing alarms and groups to the site evacuation system to ensure that under a building radiation alert condition all personnel are safely evacuated.

Omniflex's range of independent alarm systems such as the SIL 1 Omni8/16C range, can also be integrated to provide independent backup for critical alarms, ensuring the appropriate levels of safety in the system can be achieved.

PFD and MTBF data is available to aid in the verification of safety related system performance to meet standards such as EC61508.

Safety is a critical issue in the nuclear industry. In accordance with the requirements of the UK Nuclear Installations Inspectorate, every nuclear site licensee in the UK must justify their safety case in order to operate in the UK, which also involves substantiating the safety certification of each instrument involved.

The SIL 1 Omni8/16C range of alarm annunciators from Omniflex has been in use on many of the major UK nuclear facilities for many years and was among the first annunciators to be assessed by EMPHASIS substantiation tool.

The EMPHASIS tool was developed to assist the nuclear site operators to achieve a common level of substantiation whilst eliminating duplication of effort in product approvals.

RSS System Features

  • Integrate any radiation monitor old or new i.e Alpha, Beta or Gamma monitor from different manufacturers into the same system.
  • Stack control and monitoring to meet regulatory standards
  • Cyclotron monitoring and control systems.
  • Remote door locking and door warning signs.
  • Future proof modular design.
  • Real time alarm and event management
  • SCADA systems to provide data acquisition, control analysis, reporting, visualisation , alarm handling and data logging
  • Maxilarm and Omni 4000 system provides an alarm and event management interface in accordance with the EEMUA191 guidelines.

Omniflex RSS System Benefits

  • Extensive proven is use, including that of the use of Conet within the Nuclear Industry. With many RSS systems installed since 1998 having been based on a Maxiflex / Conet combination. Other systems have been Maxiflex / Ethernet and Teleterm M2 / Radio/ Conet.
  • Very easy expansion and adaptability for any type or manufacturer of radiation instrument using any combination of RS422 or RS458 (proven interfaces for Canberra, Labimpex and Berthold)
  • A mix of communications media may be applied to suit the site including Conet/c (any grade of 2 core cable up to 10kms without the need for repeaters), Modbus, Ethernet, PSTN and Radio.
  • Totally open system architecture allowing other 3rd party systems to interface if required in the future.Optional IEC61131-3 control if required in all 5 programming languages + flow chart.
  • Emphasis Assessed SIL1 Alarm Annunciators
  • Industry approved SIL 2 Door Warning Signs

EPGMS System Features

Omniflex EPGMS systems provide the following:

  • An interface with the plant I/O signals via the sites existing RS485 network cabling for Berthold Gamma outstations and to the meteorological equipment.
  • Acquire data from the plant at 5 second intervals
  • Update the Master/Slave SCADA workstation databases with real time plant data
  • Perform engineering conversions on all analogue plant input data. These include for example Dose Rates.
  • Carry out alarm checking on all analogue and digital inputs against either high or low alarm level and displaying alarms on a dedicated alarm screen on the SCADA system as well as providing relay output to the station Group 1 Alarm System.
  • Provide independent displays as demanded by the systems users
  • Provide customised user selectable colour display formats for operational information including mimic, alpha-numeric, configurable real time and historical trending and alarm lists display.
  • Able to perform mathematical functions on the data and display it graphically.
  • Provide on demand print outs of current or logged data including screen dumps.
  • Incorporate self diagnostics and alarm facilities.
  • Provide a watchdog output to alarm a workstation failure.