As the thick metal door clicked shut behind me, a low persistent hum filled my ears. My eyes adjusted to the darkness and immediately focused on a square of blue light that filtered through an opening in a metal grate on the floor. Feeling as though I was walking up to a portal from another dimension, I peered down into electric blue water that was so still it looked completely invisible. Twenty-five feet beneath its surface sat the sample rings and fuel cells of a nuclear reactor.
Most of my reporting takes place on the phone or via video call, but every once in a while, I get the lucky opportunity to meet a scientist in person. On a warm February afternoon earlier this year, I drove south from Los Angeles to the University of California, Irvine (UC Irvine) to do precisely that.
About one week earlier, I had been chatting with Ian Horvath, the chief executive officer of Serva Energy, for a new episode of our podcast, DDN Dialogues. The researchers at Serva Energy had discovered a new method of producing the radioactive isotope actinium-225. This configuration of subatomic particles is somewhat of a Goldilocks isotope when it comes to radioisotopes for cancer treatment: It doesn’t stick around in the body for too long or too little, is more powerful than other available radioisotopes, and doesn’t travel too far from the tumor, reducing off-target effects. The main problem has been making enough of it — until now.
Horvath and I talked for almost an hour about actinium-225 and his team’s research. Near the end of the interview, when I mentioned that I was based in Los Angeles, he offered me an opportunity that I couldn’t turn down: the chance to visit the nuclear reactor his team uses to create actinium-225.
To say I was excited is an understatement. I ran downstairs, scaring my dog out of her afternoon nap in the process, and told my fiancé that I was going to get to see a real-live nuclear reactor. And I was going to record as much as possible of my visit to bring the DDN Dialogues listeners along!
Exactly one week, a background check, and numerous reminders to wear close-toed shoes later, it was time to leave my apartment and head south to Irvine. (Knowing Los Angeles traffic, I left at 11 AM for a 2 PM tour.)
I had hoped that I’d be able to record audio inside the nuclear reactor laboratory, but when I asked, I learned that neither audio nor video recording were allowed; photos, however, were fine. (Take a look at the episode page for this podcast to see the photos I took!) To capture as much of the experience as possible, I figured why not record the moment I arrived. I felt silly as I recorded myself getting out of the car at UC Irvine, but that small snippet of sound ended up being one of my favorite parts of the final episode.
Soon enough, I met up with Horvath and his UC Irvine collaborator Sarah Finkeldei, a nuclear chemist, and they led me through a labyrinthine series of hallways and elevators to a nondescript locked door. Past a second set of doors, I walked into what looked like a mission control room. A long desk peppered with knobs, switches, and screens ran down the center of the room, and against it stood a wall of windows looking into the nuclear reactor room. In the control room, John Keffer, who runs the nuclear reactor laboratory, gave me a quick primer on nuclear chemistry and how nuclear reactors work. Did you know that you’re exposed to more radiation from a banana than from a running nuclear reactor? He also explained how scientists have used this particular reactor for all sorts of fascinating projects: measuring mercury levels in local fish, assessing the chemical composition of a medieval mosaic from Prague, and even analyzing one of the bullets from President John F. Kennedy’s assassination.
When it was time to see the reactor, I slipped a dosimeter around my neck and followed Horvath and Finkeldei into the reactor room. We spent what felt like a solid five minutes just sitting on the edge of the metal grate, looking at the reactor core. I very carefully gripped my phone so that I wouldn’t accidentally drop it into the reactor pool as I took some photos — there would be no getting it back if I did!
After taking our fill of the reactor, Horvath switched the lights back on and showed me around the rest of the laboratory. There was a detector made of pre-1940s steel — steel made after the 1940s is contaminated with radionuclides from the atomic bomb tests — as well as a pneumatic tube system to shoot particularly radioactive samples directly into the reactor, which reduces researchers’ exposure.
It wasn’t until Horvath took me to the laboratory where the team separates their newly generated actinium-225 from the radium-226 starting material that I really got a sense of the danger involved in this process. We stayed in an area of the lab devoid of radioactivity, but the occasional beeping of a Geiger counter on the wall, set closer to the chemical fume hoods that housed the radioactive samples, reminded me of the hazards sitting just a few feet away.
Over the next few weeks, I talked with more researchers to fill in the gaps in my reporting. Susan Moran, the former Chief Medical Officer at RayzeBio, explained just how incredible actinium-225 has been in the clinic in the company’s current clinical trials compared to the currently available therapies, and Valery Radchenko, a research scientist at the TRI-University Meson Facility (TRIUMF), patiently answered all of my questions about the different ways nuclear scientists can make actinium-225.
As I began putting the episode together, I thought about all the ways I could incorporate what I saw and learned at the nuclear reactor site visit into an audio story. I couldn’t wait to find the perfect sounds to represent alpha and beta particles, but most of all, I was excited to find a way to really set the scene and have the listener experience the same feelings that I did, gazing into the depths of the nuclear reactor for the first time.
I wondered, why not recreate the sounds I heard during my visit to put the listeners in the scene? I knew I wanted some sounds of the outdoors to represent me walking through the UC Irvine campus to the building that houses the reactor, so I popped outside and walked to a quiet street in my neighborhood and hit record. To recreate my footsteps walking down many hallways, I tried something similar; except this time, I put on my winter boots and recorded myself walking on the tile in my bathroom. The elevator sound was the elevator in my building, and the closing door was the one to my apartment parking garage. As I layered these sounds under my narration describing my experience walking into the reactor lab, I felt like I had almost captured it. The anticipation was certainly there. Then, I found a music track with a soft hum that ebbed and flowed. That was the piece that brought everything together.
Getting to talk with Horvath and Finkeldei in their natural environment and to see where they do their work was very exciting. This podcast episode would not have been the same without it. It’s an experience that I won’t soon forget.
