As the second step in creating his “algae sponge,” Garner pipetted the contaminated bacterial cells to a larger vessel containing a culture of Ulva at approximately the same cell density, water temperature, and salinity described in Grogan’s thesis. Then he read the last two chapters of the manuscript as he waited for the alga solution to respond, admiring the pale yellow sunrise of a new day as it dawned through the stained, dust-shrouded windows of the lab.
Interrupting Garner’s reverie, Alvarez arrived with breakfast and they roused Junko.
“I see what you’re doing, Brock,” Junko said as she munched on a bagel, “but it seems like an unduly complex design. If you’ve already demonstrated a high uptake rate by the Thiouni in solution, then why not simply cool the solution enough to kill the bacteria?”
“Think about it, Doctor,” Garner coaxed her.
“Sorry,” Junko said. “It’s too early in the day for my brain to be functioning at full speed.” She chewed her bagel a moment longer.
“Well, for one thing, the dead cells could release the radionuclides back into solution.”
“I suspect they would,” Alvarez said. “Especially if the isotopes weren’t first converted to an inert form.”
“And if not that, there would be the risk of contaminating the sediment on the bottom,” Junko said. “The source of the radiation would just be re-created somewhere else on the bottom.”
“My thoughts exactly,” Garner said. “Hence the Ulva sponge.”
“So what will we use to take the Ulva out of solution?” Junko asked. “We can’t just leave it stuck to the ice.”
“For the time being, I’ll be happy to show that the alga can collect the radioactive bacteria on its surface,” Garner replied. “At least, it’s a much larger cell than we might be able to collect with more traditional sampling devices.”
“You mean nets?” Junko asked.
Garner shook his head.
“The phytoplankton cells are still too small. They’d slip through the mesh almost as easily as the bacteria.”
“What then?” Alvarez asked.
Garner shrugged again, uncertain of the answer.
“Still working on that.”
They returned their attention to the experimental dishes Garner had set up. Each dish was positioned under the fluorescent microscope, then a camera on the scope projected the activity in the dish onto a television screen. As the researchers watched, the Ulva cells, seeded onto an ordinary ice cube and pushed slowly through the solution, collected the Thiouni cells.
Garner then inserted the dosimeter probe into the dish containing the cleaned solution. The instrument showed a reduction in radioactive content by more than 99.96 percent — the radiation had been almost completely removed from the seawater.
“Eureka,” Junko said, breaking into a huge smile.
“Bingo,” Alvarez agreed.
“Hot damn,” Garner said, relieved but not wholly convinced. “Or whatever we mad scientists are supposed to say.”
There were still six hours until their scheduled return to the Phoenix.
With the encouraging news from the laboratory bench, Garner and Alvarez turned their attention to Junko’s borrowed computer, which she had finished calibrating.
“I’d like you two to meet PATRIC,” she said, “the handy little gizmo that I hope will add a few more pieces to our jigsaw puzzle.”
“PATRIC?” Alvarez asked. “I’ve never heard of it, though that isn’t much of an admission for a Luddite like me.”
“I haven’t heard of it either,” Garner admitted.
“Boys, boys.” Junko smacked her lips. “I thought girls were the ones who found computers icky. PATRIC is computer-modeling software designed to calculate the direction and magnitude of radioactive fallout. It’s kind of an advanced descendant of models like MESODIF or TRAC, only it works in real time,” she explained. “Ordinarily it uses Air Force weather data to estimate radiation dispersal through the atmosphere.”
“Couldn’t weather or defense satellites do the same thing?” Alvarez asked.
“They could, if the source of the radiation was airborne or on the surface,” Garner said. “But in this case, there is no fallout cloud. The atmosphere is comparatively clean and the radiation source is below the surface.”
Junko turned back to the computer and her fingers flew rapidly over the keyboard.
“With PATRIC, a fluid is a fluid — whether it’s air, water, or sand. What I’ve done is take the density and viscosity assumptions for air currents and replace them with the data recorded for the water currents.”
“Clever,” Alvarez said.
“Often, the first forty-eight hours after an accident provide the only reliable data for where the fallout is going to travel,” she continued. “We’re way behind in this case, but we have a lot of individual field measurements we can use to hind cast the model. That’s what I was doing half the night, inputting our data.”
“If PATRIC is a military application,” Alvarez asked, “then why isn’t the military doing this kind of analysis?”
“For one thing, they refuse to admit there’s a problem,” Junko said. “For another, even if they modified the program as I have done, they wouldn’t have any real-time data from the gamma specs, or temperature, salinity, and current information along the Phoenix’s cruise track.”
“But you do,” Alvarez said.
“Thanks to Medusa,” Junko replied.
“Hmm. I always suspected there was a useful purpose for electronic gadgets in fieldwork,” Alvarez said, giving Garner a mischievous wink.
“The sooner the contamination is reliably modeled, the better,” Garner said. “Then we can continue to update the known variables until we get a very accurate real-time scenario.”
“Then you can tinker with the computerized scenario to see the outcome of various actions before actually doing them,” Alvarez concluded.
“In theory, yes,” Garner replied. “But no matter how good a model is, Mother Nature inevitably manages to throw us a curve ball.”
On the computer’s screen, the data were translated into a three dimensional plot of the “cloud” as it appeared beneath the surface of Foxe Basin. As Garner had predicted, the highest levels of contamination were concentrated around the temperature anomaly created by the heat-liberating reaction of the radionuclides.
“It’s not as contained as I’d like,” Garner said, “but most of the contamination seems to be concentrated along the heat gradient.”
“And in wildlife. And in humans,” Junko added.
“But not in the sediment and not spread over a large, diffuse area,” Garner said. “That’s encouraging. At least we have a target to shoot for.”
“Do you really think the Ulva will be enough to bring the bacteria to the surface and soak it up?” Alvarez asked.
“It won’t need to,” Garner said. “As long as the alga is there, in abundance, wherever the heated water reaches the surface.” He studied the computer plot of the slick once more.
“Right now, what I’m more concerned about is stemming the flow at its source. Can you back it up that far?” he asked Junko.
“I can try,” she said. “We can factor in the radionuclides we know of chiefly cesium, strontium, and plutonium which have a known half-life. Using the long-lived isotopes, we can estimate the original amount of radiation and the possible distance from the source. The gamma spec is showing trace amounts of others, but they have a much shorter half-life and will probably dissipate on their own.”