U.S. Spent Nuclear Fuel Storage, Congressional Research Service Report for Congress

Regardless of the outcome of the ongoing debate about the proposed Yucca Mountain geologic waste repository in Nevada, the storage of spent nuclear fuel (SNF)—also referred to as “high-level nuclear waste”—will continue to be needed and the issue will continue to be debated. The need for SNF storage, even after the first repository is opened, will continue for a few reasons. <br/>• The Obama Administration terminated work on the only planned permanent geologic repository at Yucca Mountain, which was intended to provide a destination for most of the stored SNF. Also, the Yucca Mountain project was not<br/>funded by Congress in FY2011 and FY2012, and not included in the Administration’s budget request for FY2013.<br/>• Even if the planned repository had been completed, the quantity of SNF and other high-level waste in storage awaiting final disposal now exceeds the legal limit for the first repository under the Nuclear Waste Policy Act (NWPA).<br/>• The expected rate of shipment of SNF to the repository would require decades to remove existing SNF from interim storage. Accordingly, the U.S. Nuclear Regulatory Commission (NRC) and reactor operators are considering extended SNF storage lasting for more than 100 years.<br/>The debate about SNF typically involves where and how it is stored, as well as what strategies and institutions should govern SNF storage. The earthquake and tsunami in Japan, and resulting damage to the Fukushima Dai-ichi nuclear power plant, caused some in Congress and NRC to consider the adequacy of protective measures at U.S. reactors. The NRC Near-Term Task Force on the disaster concluded it has “not identified any issues that undermine our confidence in the continued safety and emergency planning of U.S. plants.” Nonetheless, NRC has accepted a number of staff recommendations on near-term safety enhancement, including requirements affecting spent fuel storage and prevention and coping with station blackout. NRC is not requiring accelerated transfer of SNF from wet pools to dry casks, but the SNF storage data from the last several years indicate that accelerated transfer has already been occurring.<br/>As of December 2011, more than 67,000 metric tons of SNF, in more than 174,000 assemblies, is stored at 77 sites (including 4 Department of Energy (DOE) facilities) in the United States located in 35 states (see Table 1 and Figure 5), and increases at a rate of roughly 2,000 metric tons per year. Approximately 80% of commercial SNF is stored east of the Mississippi River. At 9 commercial SNF storage sites there are no operating nuclear reactors (so-called “stranded” SNF), and at the 4 DOE sites reactor operations largely ceased in the 1980s, but DOE-owned and some commercial SNF continues to be stored at DOE facilities. In the United States, SNF is stored largely at nuclear reactor sites where it was generated. Of the 104 operating nuclear reactors in the United States, all necessarily have wet storage pools for storing SNF (wet pools are required to allow for a safe “cooling off” period of 1 to 5 years after discharge of SNF from a reactor). Wet storage pools are used for storage of approximately 73% (49,338 out of 67,450 metric tons of uranium, or MTU) of the current commercial SNF inventory, whereas the remaining 27% (18,112 MTU) of commercial SNF is stored in dry casks on concrete pads or in vaults. As wet storage pools become filled to capacity using “dense packing” storage methods, dry storage is increasingly being used, although there are 27 sites with 36 wet storage pools with no current dry cask storage capabilities. This report focuses on the current situation with spent nuclear fuel storage in the United States. It does not address all of the issues associated with permanent disposal of SNF, but rather focuses on the SNF storage situation, primarily at current and former reactor facilities for the potentially foreseeable future.