What Should Be Done About Spent Nuclear Fuel Storage?
The New York Times carried an article this week about the use of metal storage casks to store spent nuclear fuel rods.
The story focused on the 57,000 lb storage casks being held on-site at the LaSalle nuclear power plant near Marseilles, IL.
The station is built on a 3,055-acre site with a 2,058-acre man-made cooling lake, which is also a popular fishery managed by the Illinois Department of Natural Resources.
Units 1 and 2 began commercial operation in January 1984 and October 1984, respectively. Both of LaSalle’s units are boiling water reactors designed by General Electric. LaSalle’s Unit 1 is capable of generating 1,138 net megawatts (MW), while Unit 2 is capable of generating 1,150 net MW. Together the units can produce enough energy to power more than 2.3 million average American homes.
More about this issue below the squiggle ⤵
Spent Fuel Storage in Pools
Most of us have heard much about the storage pools for spent fuel rods. The earthquake and tsunami in Japan and the resulting calamity at Fukushima have put those pools in the news. Pool storage at LaSalle and the other nuclear facilities across the country and around the world is becoming a bigger problem. The picture below is from LaSalle. It looks kind of pretty blue and calm. How could it be a problem? They are running out of room.
According to the U.S. Nuclear Regulatory Commission, these storage pools are safe with concrete and steel construction, deep water which serves as a coolant and shielding. As of the end of 2009, there were 62,683 metric tons of commercial spent fuel accumulated in the United States.
Of that total, 48,818 metric tons – or about 78 percent – were in pools, while 13,856 metric tons – or about 22 percent – were stored in dry casks. The total increases by 2000 to 2400 tons annually.
I visited a pool storage facility in the '70s. At that time, the hope was for the continued development of spent nuclear fuel reprocessing which would allow the fuel pellets in the rods to be made into new enriched pellets for continued use. This was to mitigate the pool storage problem of them eventually filling up to capacity. From the Union of Concerned Scientists...
In the late 1970’s, the United States decided on nuclear non-proliferation grounds not to reprocess spent fuel from U.S. power reactors, but instead to directly dispose of it in a deep underground geologic repository where it would remain isolated from the environment for at least tens of thousands of years.
While some supporters of a U.S. reprocessing program believe it would help solve the nuclear waste problem, reprocessing would not reduce the need for storage and disposal of radioactive waste. Worse, reprocessing would make it easier for terrorists to acquire nuclear weapons materials, and for nations to develop nuclear weapons programs.
Nuclear Fuel Storage Casks
As pools fill with the cooling spent fuel rods, the older ones can be transferred to dry cask storage. This has been done as early as after 3 years in the pool. Regulations ask for 5 years of pool storage. The normal amount of time is 10 years.
The NRC believes spent fuel pools and dry casks both provide adequate protection of the public health and safety and the environment. Therefore there is no pressing safety or security reason to mandate earlier transfer of fuel from pool to cask.
Many members of congress are calling for the transfer to metal casks to be speeded up, according to Congressman Ed Markey of Mass. They are thought to be capable of withstanding an earthquake or a plane crash, they have no moving parts and they require no electricity. Cooling is provided by air flow through the cask.
How Long Are They Certified
According to the Spent Fuel Storage FAQ site, NRC regulations do not specify a maximum time for storing spent fuel in pool or cask.
The agency’s “waste confidence decision” expresses the Commission’s confidence that the fuel can be stored safely in either pool or cask for at least 60 years beyond the licensed life of any reactor without significant environmental effects. At current licensing terms (40 years of initial reactor operation plus 20 of extended operation), that would amount to at least 120 years of safe storage.
However, it is important to note that this does not mean NRC “allows” or “permits” storage for that period. Dry casks are licensed or certified for 20 years, with possible renewals of up to 40 years. This shorter licensing term means the casks are reviewed and inspected, and the NRC ensures the licensee has an adequate aging management program to maintain the facility.
Workers who transfer the rods to the casks and them move the casks to the storage pad receive about a quarter of their annual exposure of radiation. Workers avoid raising the casks directly over the fuel in the pools in case it fell. They also stop work with thunderstorms to avoid power outage problems.
Once the casks are set in place outdoors on the concrete pad, maintenance is simple. They are checked twice a day to see that the air vents are not blocked. Cask manufacturers forecast a healthy future for their product.
“I joke my children will be doing my job,” said Joy Russell, a corporate development director at the manufacturer Holtec International.
What Are Your Thoughts?