A new form of Raman spectroscopy technology could make it safer and cheaper to identify radioactive contamination or other hazardous substances in waste stores and nuclear facilities undergoing decommissioning.
Raman spectroscopy is one of the most effective techniques for identifying specific chemical compounds but is rarely used in nuclear decommissioning because access constraints and high radiation fields can prevent the spectrometer from working at its typical effective range.
Now, a team from Jacobs and Tonbridge, Kent-based IS Instruments have designed a new type of Raman system which can detect a weak laser signal several metres from the target. The team has found also a way to mount the Raman probe onto a remotely operated vehicle or robot arm, which enables the probe to get within two metres of the target and send a signal down an optical cable to the main Raman instrument positioned tens of metres away.
“Standard equipment often cannot detect specific chemical agents, either because it can’t get close enough or because the signals are crowded out by the overall radiation levels,” said Clive White, Jacobs Critical Mission Solutions International Senior Vice President. “This new type of Raman system is an important breakthrough for the nuclear industry because it provides greater certainty about the presence of hazardous materials in high radiation waste facilities, making the materials easier, cheaper and safer to detect.”
Jacobs and Innovate UK have provided funding to take the system from proof-of-concept to commercial application. According to Jacobs, it is being used to detect uranium and substances including kerosene and tri-butyl phosphate, which are used in reprocessing operations and can indicate the presence of plutonium or uranium contamination.
Legacy nuclear facilities can contain significant amounts of unidentified or unknown waste materials, so improved characterisation capability can reduce decommissioning costs and timescales.
Raman technology is also a key feature of a new integrated decommissioning system built by Jacobs, which won a recent government-funded innovation competition and will be demonstrated inside former fuel reprocessing facilities at Sellafield later this year.