The Adventures of Safety Secretary Shepherd

Culham Centre for Fusion Energy is the home of two of the world’s leading tokamaks; the Joint European Torus and the Mega Amp Spherical Tokamak. To ensure that both machines can provide world class physics research, and continue to do so for many years, CCFE has to take its responsibilities towards the safety of the machines, its employees and the surrounding environment very seriously. Overseeing most of the safety processes on site is the Site Safety Working Party, known as the SSWP. 

As one of the secretaries for the SSWP I get a unique insight into the workings of the committee and the dedication to safety shown at Culham. The SSWP is made up of representatives from many different departments; from health physics to central engineering, as well as off-site safety experts. This gives the committee a wide range of experience and professional knowledge to draw upon when reviewing the safety practices of the various departments and facilities. Every month the SSWP meets to review safety forward action plans for the various facilities, renew a holders Authority to Operate (ATO) for a facility and comment on the safety aspects of the many modifications made to the equipment and experiments on site. To ensure the meetings are not all work and no play CCFE provides cake.

One of the most interesting duties of the SSWP, at least from the secretaries’ point of view, is touring the ATO areas as part of the ATO renewal process. These tours are an excellent opportunity to see parts of the CCFE site outside my normal working routine, and to directly see the importance of a good safety culture. One example that stands out is the tour of the Active Drain & Trade Effluent facility. This facility is on the edge of site, so far out in fact I didn’t even know it existed until the tour. Here all of the trade waste and mildly tritiated water is stored before being safely removed. While on the tour it was explained to us the care that is taken to dilute down the tritium to levels far below acceptable levels set by the government. It was great to see how importantly CCFE took its responsibility to protect the environment. And the environment seemed to agree heartily, as one of the trade effluent tanks was playing host to a family of ducks.

 

When one is asked to explain the advantages of fusion over other energy sources one of the most quoted is the small amount of radioactive waste produced as opposed to fission reactors. No radioactive by-products like caesium-137 are produced in the fusion reactions on JET and MAST, just helium and high energy neutrons. The only radioactive products are materials activated by these neutrons, for example the carbon composite tiles removed during a recent JET upgrade. As with all other safety concerns on site CCFE takes the risk these active components pose very seriously. The components are stored in containers and only once the activity has fallen below very strict safety limits can the materials be disposed of. 

Acting as SSWP secretary has given me the opportunity to experience aspects of CCFE outside my day-to-day job. These are the sorts of opportunities that are abundant at CCFE; from the graduate scheme to fusion outreach. And, did I mention there is cake?

by Alastair Shepherd