Updated 9 p.m. Thursday: We've ended our live Twitter stream from the meeting; you can read the archive of our live stream below.
Previously: Members of the public will get their first chance Thursday to hear what's next for the closed San Onofre Nuclear Generating Station as environmental groups raise questions about the storage of nuclear waste onsite.
The Nuclear Regulatory Commission scheduled a meeting at 6 p.m. in Carlsbad to describe the process for decommissioning the plant. Doors were set to open an hour earlier for security screening.
Read Ed Joyce's tweets live from Thursday night's meeting:
Previous meetings on the San Onofre nuclear plant have drawn large crowds, and Thursday's event has been scheduled for a ballroom at the Omni La Costa Hotel that can hold nearly 2,000 people.
It's just the start of a decades-long process, but questions about storing nuclear waste along the ocean are already bubbling up.
The nuclear plant on the coast between Orange and San Diego counties has been shut down since January 2012, after radioactive steam escaped from damaged tubes inside one of its reactors.
In June, Southern California Edison moved to close the plant permanently.
Edison International Chairman Ted Craver told reporters that closing the plant would take decades and result in spent nuclear fuel being stored "for a very long time" on site.
While they initially celebrated San Onofre's closure, environmental groups are now focused on the safety of storing nuclear waste there.
Environmental groups in San Diego and Orange counties are girding for a long fight as decommissioning could take several decades and on-site nuclear waste storage continues indefinitely.
"It ends when all the spent fuel is inert or is shipped to a remote site like Yucca Mountain," said Glenn Pascall, who heads the Sierra Club's San Onofre task force.
Until then, dry casks holding San Onofre's nuclear waste could be sitting alongside the Pacific Ocean, and a stone's throw from Interstate 5, for hundreds or even thousands of years.
Gene Stone is with the San Clemente-based Residents Organized for a Safe Environment, one of several groups that pushed for the plant's closure.
"All of the nuclear waste is still out there, so we still have a high potential for an accident there," said Stone. "And people should not be thinking that we are safe because the plant is closed. We are safer, but we are not safe."
The NRC explains on its website that dealing with spent nuclear fuel rods is a two-step process. First, the rods are stored in deep pools made of reinforced concrete with steel liners meant to contain radiation. The rods are left to cool in these pools anywhere from three to 10 years. They are then transferred into dry casks. There are already dozens of such casks at San Onofre, holding nuclear waste from an earlier reactor that was decommissioned in 1992.
"These casks are also then stored in buildings with fairly thick walls that are actually more seismically hardened than the reactor itself," said Bob Alvarez, a former official with the Department of Energy and now with the Institute for Policy Studies. "The roof of the cask storage module is five-feet thick."
Absent a long-term nuclear waste repository -- like the proposed facility at Yucca Mountain, nuclear plants around the country are having to store spent fuel rods on site.
Alvarez said dry storage casks are inspected and monitored regularly.
"I think it's slowly dawning on people that these reactors are not just machines that generate electricity, they're also becoming major radioactive waste management operations," Alvarez said.
And it's that waste management that concerns Glenn Pascall, who heads the Sierra Club's San Onofre task force.
"We have a lot of fuel there. It is packed in much higher densities than were designed, and a fuel type was used that was a high-burn fuel that apparently is trickier to handle," said Pascall. "So right next to populated areas, we have this huge challenge of what to do with the waste, and we're beginning to realize it's just as big a challenge as the whole debate over the shutdown."
The "high-burn" fuel Pascall referred to was used in San Onofre's nuclear reactors. Alvarez says high-burn fuel rods give off more radiation than other fuel rods.
"The issue with high burn-up fuel is that you're going to have a much larger amount of radioactive materials that give off a lot more decay heat and radiation in particular, which puts a lot more strain and stress on whatever is containing it," he said.
But Alvarez said high-burn fuel rods are safer in casks than storage pools.
Darin McClure, a San Clemente web marketer, doesn't want any nuclear waste stored at San Onofre no matter how it's stored.
"It's still a danger having it sit there on an earthquake fault line, in a tsunami zone — those are still problems here, McClure said. "The problem at Fukushima today isn't the nuclear reactors melting down, it's how are they going to get rid of all that spent fuel. So we need to make sure it's all moved out of there before we have that kind of Fukushima incident."
Alvarez, with the Institute of Policy Studies, said despite Fukushima's myriad other problems, nine dry casks stored at the plant came through the earthquake and tsunami intact.
He also said the Nuclear Regulatory Commission has yet to issue a license to transport high-burn nuclear waste in this country.
"Dry casks really represent a greater significant reduction in potential consequences if something goes wrong," Alvarez said.
He said the spent fuel pools are the biggest potential on-site risk at San Onofre because they were designed to be relatively short-term storage facilities.
"The potential hazards of water draining from the pool from an earthquake, for example, could lead to a very large release of radioactivity," Alvarez said.
The details of how long those pools will be used at San Onofre is one of many questions environmental groups hope to have answered at the NRC meeting in Carlsbad.
This story has been updated.