ATEX & hazardous areas
in the active areas was greatly reduced, and accelerated the delivery and active service of the system. The units have since been used on other Sellafield site projects and are specified to be used on new projects planned over the next five years. The technological developments of the RPN1 led to Omniflex winning the Nuclear Decommissioning Authority’s Innovation Award in 2016.
beta and gamma levels. If a high-level radiation alert or instrument failure occurred, the monitor would detect it and sound a local area alarm. However, to comply with the industry’s strict operational guidelines, networking of radiological protection systems became standard practice. To achieve this, the industry had to deal with extreme costs and disruption to install, network and test devices. This is because each system was bespoke, required significant amounts of new cabling and a skilled wireman to install and test each individual part of the system. All of this work would take months to complete and validate, only to be repeated whenever maintenance was required or an instrument needed moving to a new area of the facility. When the National Nuclear Laboratory (NNL) was tasked with installing 130 data collection points to connect large volumes of radiation protection instruments at Sellafield’s nuclear site, it was not feasible to use traditional methods. It would have taken months to complete and involve significant cabling and installation costs. To overcome these challenges, Omniflex designed the RPN1 radiation monitor interface device in collaboration with Steve Parkin, senior project manager for NNL. The RPN1 is a gateway device, developed to simplify the process of data collection from a variety of radiation protection monitors via their RS485 communications ports and connects them to the plant’s SCADA system. It is a COTS product that can be installed in minutes, saves thousands of man hours of work and eliminates the need to run miles of expensive power cables to each monitor. Furthermore, it is standardised to meet ISO 9001 quality levels, so there is no need for additional third-party inspections during installation or testing.
Installing the RPN1 across the Sellafield site helped NNL save over £1m in costs, ensured that the time spent by personnel
SOUND THE ALARMS
Many nuclear sites rely on control systems full of complex visualisations to warn operators of imminent danger. This can be overwhelming for operators and sometimes counterproductive. In the event of danger, it is vital that the safety systems alert operators quickly and efficiently so they can respond appropriately.
Alarm annunciators are panel-based alarm indicators that are hard-wired directly into relevant processes. If there is an abnormal event, the relevant window on the panel lights up and the alarm emits a sound, immediately giving operators the necessary information to act quickly. However, many alarm annunciators in use at nuclear sites today were first installed decades ago and do not meet the current IEC 61508 SIL standards.
designed for radiation and airborne contaminant warnings, designed to meet the requirements of SIL-2 safety systems as defined in IEC 61508. These serve as a safeguard against personnel inadvertently entering plant areas where abnormal radiological and other hazardous conditions are present. If airborne contamination or high radiation conditions are present in the area, a bright flashing visual is displayed, warning local operators of the hazard and deterring entry to the contaminated area.
SAFELY STORING WASTE
Operator response times are an important part of the SIL-rating, making it vital that alarms maximise, rather than impede, the operator’s ability to respond and act quickly. Physical alarm annunciators must be kept up to date and must only display the safety, health and environmental alarms that plant operators must respond to. Omniflex supplies SIL-1 certified alarm annunciators for the UK’s nuclear industry for both new and direct retrofits for the old, outdated systems and can work with the nuclear industry to upgrade alarms in line with the latest technology with minimal disruption. It also supplies door warning alarm annunciators and slave alarm units
The final area of nuclear site safety to highlight is the safe storage of nuclear waste. Different kinds of waste require different kinds of containers and different sets of key parameters that require monitoring. However, regardless of type, all nuclear waste is extremely hazardous and must be treated with caution. Sensors and any other electrical devices in waste storage locations must operate for decades in an extremely hazardous environment and include a power supply that works for decades without human intervention. To improve its ability to monitor the condition of waste containers in long-term storage, Sellafield recently commissioned the Nuclear AMRC to develop new smart sensor technologies for waste monitoring. The project focused on developing new sensors to ensure the long-term safety of waste from the earliest years of the UK’s nuclear programme. The new sensor system provides data on the condition of the waste over decades of storage. Sellafield produces thousands of nuclear waste containers each year, all of which require on- site storage. Throughout this storage period, Sellafield must demonstrate that the waste, the container and the store are evolving as expected with in situ monitoring over decades of storage. If the nuclear industry is to prevent future high consequence accidents like Chernobyl and Fukushima Daiichi, it must continue to innovate and develop new safety systems. To find out more about COTS systems for the nuclear industry, download Omniflex’s nuclear industry whitepaper for free on its website.
Omniflex
www.omniflex.com
Instrumentation Monthly February 2023
71
Page 1 |
Page 2 |
Page 3 |
Page 4 |
Page 5 |
Page 6 |
Page 7 |
Page 8 |
Page 9 |
Page 10 |
Page 11 |
Page 12 |
Page 13 |
Page 14 |
Page 15 |
Page 16 |
Page 17 |
Page 18 |
Page 19 |
Page 20 |
Page 21 |
Page 22 |
Page 23 |
Page 24 |
Page 25 |
Page 26 |
Page 27 |
Page 28 |
Page 29 |
Page 30 |
Page 31 |
Page 32 |
Page 33 |
Page 34 |
Page 35 |
Page 36 |
Page 37 |
Page 38 |
Page 39 |
Page 40 |
Page 41 |
Page 42 |
Page 43 |
Page 44 |
Page 45 |
Page 46 |
Page 47 |
Page 48 |
Page 49 |
Page 50 |
Page 51 |
Page 52 |
Page 53 |
Page 54 |
Page 55 |
Page 56 |
Page 57 |
Page 58 |
Page 59 |
Page 60 |
Page 61 |
Page 62 |
Page 63 |
Page 64 |
Page 65 |
Page 66 |
Page 67 |
Page 68 |
Page 69 |
Page 70 |
Page 71 |
Page 72 |
Page 73 |
Page 74 |
Page 75 |
Page 76 |
Page 77 |
Page 78 |
Page 79 |
Page 80 |
Page 81 |
Page 82
