Wednesday, May 30, 2012

U.S. Spent Nuclear Fuel Storage

From FAS:

Regardless of the outcome of the ongoing debate about the proposed Yucca Mountain geologicwaste repository in Nevada, the storage of spent nuclear fuel (SNF)—also referred to as “highlevelnuclear waste”—will continue to be needed and the issue will continue to be debated. Theneed for SNF storage, even after the first repository is opened, will continue for a few reasons.First, the Obama Administration terminated work on the only planned permanent geologicrepository at Yucca Mountain, which was intended to provide a destination for most of the storedSNF. Also, the Yucca Mountain project was not funded by Congress in FY2011 and FY2012, andnot included in the Administration’s budget request for FY2013. Second, even if the plannedrepository had been completed, the quantity of SNF and other high-level waste in storageawaiting final disposal now exceeds the legal limit for the first repository under the NuclearWaste Policy Act (NWPA). Third, the expected rate of shipment of SNF to the repository wouldrequire decades to remove existing SNF from interim storage. Accordingly, the U.S. NuclearRegulatory Commission (NRC) and reactor operators are considering extended SNF storagelasting for more than 100 years.

The debate about SNF typically involves where and how it is stored, as well as what strategiesand institutions should govern SNF storage. The earthquake and tsunami in Japan, and resultingdamage to the Fukushima Dai-ichi nuclear power plant, caused some in Congress and NRC toconsider the adequacy of protective measures at U.S. reactors. The NRC Near-Term Task Forceon the disaster concluded it has “not identified any issues that undermine our confidence in thecontinued safety and emergency planning of U.S. plants.” Nonetheless, NRC has accepted anumber of staff recommendations on near-term safety enhancement, including requirementsaffecting spent fuel storage and prevention and coping with station blackout. NRC is notrequiring accelerated transfer of SNF from wet pools to dry casks, but the SNF storage data fromthe last several years indicate that accelerated transfer has already been occurring.

As of December 2011, more than 67,000 metric tons of SNF, in more than 174,000 assemblies, isstored at 77 sites (including 4 Department of Energy (DOE) facilities) in the United States locatedin 35 states (see Table 1 and Figure 5), and increases at a rate of roughly 2,000 metric tons peryear. Approximately 80% of commercial SNF is stored east of the Mississippi River. At 9commercial 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 somecommercial SNF continues to be stored at DOE facilities. In the United States, SNF is storedlargely at nuclear reactor sites where it was generated. Of the 104 operating nuclear reactors inthe United States, all necessarily have wet storage pools for storing SNF (wet pools are requiredto allow for a safe “cooling off” period of 1 to 5 years after discharge of SNF from a reactor). Wetstorage pools are used for storage of approximately 73% (49,338 out of 67,450 metric tons ofuranium, or MTU) of the current commercial SNF inventory, whereas the remaining 27% (18,112MTU) of commercial SNF is stored in dry casks on concrete pads or in vaults. As wet storagepools become filled to capacity using “dense packing” storage methods, dry storage isincreasingly being used, although there are 27 sites with 36 wet storage pools with no dry caskstorage capabilities.

This report focuses on the current situation with spent nuclear fuel storage in the United States. Itdoes not address all of the issues associated with permanent disposal of SNF, but rather focuseson the SNF storage situation, primarily at current and former reactor facilities for the potentiallyforeseeable future.

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