Global Security Newswire
Daily News on Nuclear, Biological & Chemical Weapons, Terrorism and Related Issues
NRC Staff Say More Nuclear Plant Protections Needed After Fukushima
WASHINGTON -- Staff for the Nuclear Regulatory Commission are recommending that their agency require aging atomic power plants in the United States to make upgrades that could reduce the amount of radioactivity released into the environment following an act of terrorism or a natural disaster.
During a major crisis – such as the one Japan experienced at the Fukushima Daiichi facility last year – a nuclear reactor’s cooling system can become disabled due to loss of power. When that happens, fuel in the reactor’s core can heat up and become damaged. A buildup of intense pressure can then cause the reactor’s containment vessel to rupture – in the case of Fukushima exposing highly radioactive reactor fuel to the outside world for months and causing widespread contamination.
In response to the incident in Japan, the Nuclear Regulatory Commission earlier this year ordered U.S. plants of General Electric’s Mark I design – the same used at Fukushima – to improve venting systems that are intended to relieve pressure inside a reactor’s containment vessel and prevent rupture. The same NRC order required plants of the similar GE Mark II design to install such venting systems from scratch, as they have not already done so.
The March 12 order does not, however, require that such venting systems be operable in a severe incident after reactor fuel has become damaged. This has prompted strong criticism from watchdog groups, who argue the mandate does not require venting systems at U.S. plants to be able to cope with the very incident that occurred at Fukushima.
“That is crazy,” said Paul Gunter, director of Beyond Nuclear’s reactor oversight project. “We strongly object to that as a dangerous half-measure.”
Staffers are now suggesting that the five-member, presidentially appointed commission update the order to require the vent systems to be operable following fuel damage. The staff is also suggesting that the new order require that the vent systems include filters that would limit the amount of radioactive material that escapes into the surrounding environment when the vents are opened to relieve pressure building within the reactor containment vessel, NRC spokesman Scott Burnell told Global Security Newswire
Such a venting system, combined with filtration, could be useful following either natural disasters or acts of sabotage that take out a nuclear plant’s sources of power, experts say. Such systems are already installed at nuclear power plants in Europe.
Nuclear power industry officials in the United States are opposed to the portion of the staff recommendation that involves filters, however, and argue they can contain the radioactive material in a more effective – and potentially cheaper – manner. Rather than install vent filters outside the reactor containment vessel, industry officials would prefer to modify existing reactor components to provide a filtering function, Steven Kraft, senior director for Fukushima response at the Nuclear Energy Institute, told GSN.
One way to do this, Kraft said, would be to wash the radioactive particles into existing suppression pools below the reactor using cooling water sprays. The water in the suppression pool would have the function of filtering the particles, he said. The pools already play a key role in the reactor cooling system.
A separate filtering system installed outside the reactor containment vessel, which the NRC staff are proposing requiring, would also use a large tank of water to filter radioactive particles, Kraft said. He argued that the modifications industry was proposing instead would be just as effective.
Industry’s approach could also be less expensive, Kraft acknowledged. The amount of savings could vary from plant to plant, he said.
“We don’t know – it depends on how much changes you would have to make,” Kraft said. “It could run as much as [installing external filters], it would probably run less.”
Kraft maintained, however, that money is not the issue.
“Under no circumstance is this cheap,” he said. “People shouldn’t think that we’re saying we don’t want to do this because we don’t want to spend the money -- we’re talking serious money here do what we want to do.”
Industry’s plan would “achieve all the same things NRC wants to achieve … in a far more reliable way because we’re keeping the radionuclides in containment,” Kraft said. “One of the biggest failings of the external filters is that you count on the radionuclides exiting containment and being trapped in some external tank someplace – we don’t think that makes a lot of sense.”
Burnell, the NRC spokesman, disputed Kraft’s assertion that what industry is proposing would be equally effective, however. He said industry’s plan lacks the detail that would be needed to draw that conclusion.
“The industry has offered a concept where they believe existing spray systems and other operator actions could provide adequate filtering,” Burnell said. “The staff has yet to see even a proof-of-concept proposal; to this point the industry’s presentations focus on potential filtering benefits, not how to realistically achieve them.”
Industry and NRC staff are also at odds as to how much installation of external filters would cost. While NRC staff project about $16 million per plant, NEI estimates put the figure closer to $45 million. Kraft argued that NRC staffers are only accounting for the cost of filter components plant operators would have to purchase from outside vendors and are not including the cost of additional modifications operators might have to make on-site to make the filters viable.
“Maybe you have to move something, have to install something, change procedures – all those costs add up,” Kraft said. “When you look at some of the European designs, those external filters were put in separate buildings … and that’s a seismic heavily shielded building so you’re talking a bunch of money for that.”
The NRC Advisory Committee on Reactor Safeguards essentially backed the industry position in a Thursday letter to commission Chairwoman Allison Macfarlane. The committee said it opposes a mandate for external filters and instead favors an alternative “performance-based approach” that NRC staff said in meetings last week was based on the industry proposal.
A “performance-based approach” allows more room “for innovation and may result in more effective solutions,” the ACRS letter says. It says the approach could ultimately lead to external filters being installed anyway, but does not recommend mandating such installation at this time.
Watchdog groups meanwhile support the NRC staff recommendation, according to Gunter. The “performance-based approach” described during ACRS meetings last week appeared to vague to be effective and its lack of clarity could lead to implementation delays, he said.
As it is, watchdog groups believe the U.S. government and nuclear power industry have been too slow to respond Fukushima. Gunter complains that plant operators have until the end of 2016 to comply with the existing NRC vent order. Allowing the industry to take an undefined approach to filtering, without a clear enforcement mechanism, could cause the issue to “drift into oblivion,” he said.
"We continue to be midstream on the post-Fukushima actions that were given a test by [hurricane] Sandy" Gunter said, referring to the storm last week that put the Oyster Creek nuclear power plant in New Jersey on an emergency alert. "Luckily it wasn't a class 5 or a class 3 storm ... these are all wake up calls right now."
Gunter said he is also concerned about the prospect of the five-member commission ultimately voting down the staff recommendation. He noted that one commissioner, Republican Kristine Svinicki, has already expressed opposition to a filter requirement. Svinicki argued in March that existing protective measures should prevent filtered vents from ever being necessary.
Commissioner William Ostendorff, also a Republican, told GSN in a brief interview this week that he had not yet made up his mind on the subject. NRC staff is expected to present a more detailed report to the commission later this month, he noted.
“I’m really going to wait and see what I can discern from the staff’s analysis,” Ostendorff said, adding that he recently visited a plant with a filter in Sweden in an effort to learn more about the topic. “We are and will be spending a lot of time on that issue.”
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