Ellen Gill

Favourite Thing: Getting other people as interested in radionuclides as I am



Holy Trinity School, Crawley 1998-2004. University of Exeter 2004-2007


Physics (with Quantum Mechanics and Laser Technology) Bsc Hons

Work History:

Cavendish Nuclear 2007-present

Current Job:

Shielding Specialist


Cavendish Nuclear

About Me

I’m interested in everything and I think atoms are neat

I live in the centre of Bristol, which is the best. I apologise to anyone who doesn’t live in Bristol.

Outside of work I have a lot of different hobbies as I’m terrible at doing nothing. At the moment I’m completely obsessed with swing dancing, but I also like making my own clothes, playing piano, drawing, walking, baking and reading. I also volunteer at Samaritans, which is just as important to me as my day job.

My Work

I specialise in designing and analysing shielding against gamma radiation, but know a lot about managing radiation and nuclear waste in general

Ultimately I’m responsible for keeping background radiation levels on nuclear sites safe and legal on a day-to-day basis, and I take that job very seriously, as does everyone else I work with. Radiation affects almost every imaginable aspect of running a nuclear power plant, so I’m always learning new things.

What I love about my field of work is how incredibly complex and fascinating radiation physics is when you actually get down to it. There’s so much to think about! Different radionuclides give off different types of radiation at different energies, and some of them decay (at different rates!) into completely new radionuclides again whereas some become stable. Then there’s the way radiation travels through different materials, how it can change different materials over time, and there’s the biological effects of radiation to consider, then there’s the extreme conditions found inside a reactor, unlike anything else on earth, and I could go on and on and on!


My Typical Day

Advising other people about what to do with all that radiation

I work for a consultancy so we take on all sorts of work for customers around the world, but mainly the UK. The work can be anything from advising on how best to store drums of waste to evaluating multi-million pound building designs. On a good day I get to spend lots of time building computer models, which is the fun bit. Because they’re statistical models I actually code everything from scratch.

I also have to write up my work thoroughly enough to prove my models are good enough to base engineering decisions on. It’s much like writing up a science experiment in class, but with more detail.

I do spend a lot of time working with other disciplines, but mainly civil engineers and process engineers. Civil engineers design building structures, and more importantly, make sure all the massive shield walls I’ve modelled won’t fall down in real life. Sometimes the ideal shield wall won’t work in reality so we have to figure something out together. Process engineers decide how nuclear material is moved around site so I work very closely with them to make sure radiation isn’t building up to unsafe levels at any point. At this point in my career I’m a bit of a jack of all trades – I know a little bit about everyone else’s business so I can tell them how radiological issues will affect them.

What I'd do with the money

Run engineering/physics workshops in local schools

I’m also part of STEMnet ( which helps people working in science, technology, engineering and maths to go into schools and inspire students. So teaming up with them, I bet me and my co-workers could arrange some really interesting activities to do in schools. Fancy playing around with Geiger counters? Or the remote-control robots we use to carry out operations in really high activity areas?

My Interview

How would you describe yourself in 3 words?

Curious, enthusiastic, open-minded

Who is your favourite singer or band?

I can’t possibly choose! I veer wildly between genres. Right now I seem to be having a rock and roll phase.

What's your favourite food?

Whatever’s in front of me. Except coffee, which I can’t stand.

What is the most fun thing you've done?

Taking up swing dancing, definitely. And last year I got to ride in a hot air balloon during one of the Bristol Balloon Fiesta’s mass ascents, which was really awesome too.

What did you want to be after you left school?

A tattoo artist. I actually went looking for apprenticeships but it turns out it’s neither a well-paid nor glamorous career path, so I did a physics degree instead.

Were you ever in trouble at school?

For a while I treated homework as an optional activity which, er, didn’t go down well.

What was your favourite subject at school?

At GSCE I liked art, textiles, science, english and graphic design. At A-level I found myself really enjoying pure algebra, and my school had fantastic philosophy teachers as well. Plus physics teachers seem happier with you blowing things up at A-level so I enjoyed physics the most!

What's the best thing you've done as a scientist?

Helped design a new piece of instrumention to go inside parts of reactors that have never been accessed before. This was to prove that the cores were strong enough to keep running past their original lifetime – very important as we’ve not got replacements built yet.

What or who inspired you to become a scientist?

I come from a very scientific family so needless to say I have been gently encouraged all my life, not that I needed much of a push. I must have read every single DK science book I could find when I was little.

If you weren't a scientist, what would you be?

I’m also very interested in psychology so probably a counsellor.

If you had 3 wishes for yourself what would they be? - be honest!

1)That I no longer need to sleep so I can get more done. I wouldn’t lose the ability to sleep though, I enjoy it too much. 2) An extremely nice library room to be added to my house. 3) Humanity figures out how to build commercially viable fusion reactors within the next year.

Tell us a joke.

Newton, Pascal and Young are playing hide-and-seek and it’s Young’s turn to count. As he closes his eyes and counts, Pascal runs off and hides, but Newton just stands there and draws a square around himself. Young opens his eyes, points at Newton and says “I’ve found you!”. “Incorrect.” says Newton “You’ve found one Newton per metre squared. You’ve found Pascal.”

Other stuff

Work photos:

I can’t actually show you my office! There’s lots of confidentiality around nuclear work, and the security levels my company works to means no photos for the public. But as most of my job is done on a computer I work in a fairly regular looking office with lovely people who bring in cake on a frequent basis.

Some modelling work:



This picture is a really simple example of what the code I use is actually doing when I run it. There is a radiation source sitting at one end of a stepped corridor through a slab of concrete with air on the other side. The code generates all these random particle paths through the materials until enough reach the other side to give a good statistical result. If you look carefully you can see more particles are bouncing around inside the concrete, getting redirected and absorbed, whereas the ones in air are all travelling in straight lines. We use stepped corridors a lot in nuclear sites to reduce the amount of radiation streaming directly towards people.


I’ve removed a *lot* of the details here for confidentiality reasons, but this shows the scattering of radiation around a nuclear facility design. Here, gamma radiation is actually streaming upwards through the roof, scattering in air and causing peaks several metres from the building itself. Not huge amounts luckily, but this is the kind of thing that needs to be checked. The scale at the bottom is the number of particles that have landed in each square of the areas either side of the facility.


The pile cap of a reactor! This is Torness power station in Scotland, which is my favourite station that I’ve done time working in. Our currently operating fleet of stations are an outstandingly efficient design completely unique to the UK. This is what will be keeping me in a job for years to come, even after they’ve all shut down. And of course any new ones will be keeping me very busy as well…