J.M. Dodds, M.J. Edmondson and. D Rhodes

The National Nuclear Laboratory, Havelock Road, Workington, Cumbria, CA14 3YQ, UK.

Introduction It is hard to believe that a glass of water could be responsible for the chemical free clean up of contamination. However, recent developments in bubble technology are enabling scientists and engineers to do just that. The NNL sees many potential applications of the technology within the nuclear industry. The technique provides the ability to for enhanced cleaning without the use of additives such as surfactants meaning more simple effluent clean up. Furthermore it can be deployed with reduced spray and aerosol. The ability to clean with just cold water also reduces power bills.

Figure 3. Demonstration of the StarStream technology developed at Southampton University, (a) with only water and (b) with the nanobubble generation turned on.

Keywords: Nanobubbles, Ultra-fine bubbles, Bubbles, Decontamination, Clean up

Figure 2. Is it real? Although the two samples look the same, the sample containing nanobubbles can be seen to interact differently with a green laser. *

Figure 1. Decolourisation of water within aquatic tanks using nano bubble technology at a zoo in Japan. *

Ultrafine Bubbles

(Nano Bubbles)

Bubble Generation Many instruments and methods of generating ultrafine bubbles or nano bubbles have been identified and part of this research will consider the merits of different types of generation for potential decontamination applications. NNL are considering two systems that offer the potential for enhanced cleaning using just water. A Japanese system that has found uses at Fukushima, in Japan’s zoos, in hydroponics and even in toilet cleaning! Plus the Ultrawave ‘StarSteam’ developed at Southampton University.

Future Work - Nuclear Industry This technology is unusual in finding application before a full understanding of the technology has been developed. The underlying physics of the generation of ultra-fine bubbles or nano bubbles has generated significant interest. Whilst the majority of research considers the mechanism of the bubble generation and cleaning mechanisms; it is important for the nuclear industry to understand the bubbles lifetime and their potential impact on downstream plants.

*Figures 1 and 2 courtesy of OK Engineering Company, Osaka, Japan.

For more information on these and other similar activities please contact: Jonathan.M.Dodds@NNL.co.uk; +44 (0)19467 88964

Aim: Consider the decontamination capability and lifetime considerations of ultrafine bubbles (nano bubbles) for use in the nuclear industry.