The danger Hurricane Sandy posed to nuclear power plants along the East Coast highlights some of the same vulnerabilities that terrorists looking to release harmful radiation into the environment could exploit, watchdog groups said this week.
The unprecedented storm posed two main challenges to atomic energy facilities: rising water levels and interruptions to the electricity grid. Both have the potential to disrupt crucial cooling systems at the plants, and particularly those for pools used to cool spent reactor fuel. If spent fuel rods overheat and are exposed to air, they can cause fires and dangerous radiation releases.
In Lacey Township, N.J., the Oyster Creek nuclear power plant faced both of these challenges. High water levels threatened to submerge a water pump motor used to cool water in the plant’s spent fuel pool, Reuters reported. The situation, caused by a combination of rising tide, wind direction, and storm surge affecting the Atlantic Ocean and adjoining estuaries, prompted the facility to declare an emergency “alert,” according to the Nuclear Regulatory Commission.
In addition, the Oyster Creek plant at one point experienced a power disruption that necessitated the use of two backup diesel generators, according to Reuters.
While such auxiliary power can usually keep cooling systems for a nuclear reactor itself operating, activists warn that NRC regulations do not require that such resources also be connected to the mechanisms that cool spent fuel pools.
“As soon as the electric grid goes down, water circulation pumps stop operating,” Kevin Kamps, a radioactive-waste specialist with the group Beyond Nuclear said in a statement released during the storm.
Pool water can begin to boil within “several hours” of loss of cooling, he noted, and could leave fuel rods exposed within “several to many days.”
Kamps told Global Security Newswire that the same problems could be caused by an intentional attack.
“While high winds can knock out the electric grid, so too can sabotage or terrorism,” Kamps said. He added that “normal cooling-water flow pathways and mechanisms,” threatened by high water during the storm at Oyster Creek and other nuclear plants, “could also be disrupted intentionally.”
In the event of a disruption to the usual spent fuel pool cooling system, power-plant operators could use firefighting equipment in an attempt to replenish water lost through evaporation. Japanese authorities tried similar tactics during the Fukushima Daiichi disaster last year. Watchdog groups argue that relying on this is insufficient, however.
Steam generated by a boiling spent-fuel pool “could short-circuit critical safety systems throughout the nuclear plant,” Kamps said.
Robert Alvarez, who served as a senior adviser to the Energy secretary during the Clinton administration, noted that spent fuel pools were originally designed for temporary storage lasting no longer than five years. He cited a 2006 study by the National Academy of Sciences that said pools at nearly all of the more than 100 reactors in the United States now contain high-density spent-fuel racks that allow about five times more waste to be stored in the pool than was originally intended.
“The Oyster Creek spent-fuel pool is currently holding about 3,000 irradiated assemblies (including a recently discharged full core) containing about 94 million curies of cesium 137—more than three times more released from all atmospheric nuclear weapons tests,” Alvarez, now a senior scholar at the Institute for Policy Studies, said by e-mail. “Whether or not mega-storm Sandy portends what’s in store for the near future, it’s still too risky to use high-density spent-fuel pools as de facto indefinite storage for some of the largest concentrations of radioactivity on the planet.”
Watchdog groups have long advocated for an NRC rule that would require used fuel rods to be removed from pools and placed in hardened, dry casks as quickly as possible. Alvarez said dry casks at the Fukushima Daiichi site were “unscathed” by the earthquake and tsunami that threatened the plant’s spent fuel-storage pools last and caused meltdowns in three reactors.
Even in a worst-case scenario, the “consequences of a breach in a dry cask in terms of radioactive releases is about 2,500 times less than a spent-fuel pool fire,” Alvarez said. “Whereas a spent-fuel pool fire could create life-threatening contamination of hundreds of square miles.”
Following the Fukushima disaster, watchdog groups petitioned NRC to immediately require a number of upgrades at U.S. atomic energy plants. Among the activists’ demands were that the commission require dedicated backup power systems for spent-fuel pools and that fuel rods be removed from the pools after five years.
NRC officials rejected the demands that they act immediately on these items, but agreed to consider them in their long-term review of lessons to be learned from Fukushima. Kamps said the threats posed by this week’s storm underscored the urgency of requiring such upgrades.
For now, the commission “is focused on the current situation with the plants,” according to NRC spokesman David McIntyre, who emphasized that “all of them are safe and have performed according to design and their license conditions.
“If there are lessons to be learned from Sandy, we will look at them, but we do not have the luxury that [the watchdog groups] have of being able to jump to conclusions before a situation even plays out,” McIntyre added.
In total, the Hurricane Sandy impacted at least a half-dozen nuclear plants, Reuters reported. Other affected sites include Unit 1 of the Salem, N.J., plant – which was shut down due to high water and debris – and Indian Point 3 in New York, which went offline due to fluctuations in the power grid caused by the storm.
John Keeley, a spokesman for the Nuclear Energy Institute, which represents the nuclear-power industry, noted that the majority of nuclear plants “in the path of the storm continued to produce electricity” and that the “ones that did shut down did so safely and securely.”