So it looks like enrichment production at Paducah could start around 2024? GLE have to pay for packaging and transportation to Paducah from Portsmouth, the site will be just outside the DOE owned land but abut the existing de-conversion plant, would that be after enrichment to HALEU level is achieved is the burning question?
How long for the license after a design is finalised are they working on this aspect now? HALEU or natural grade? are we looking at two years there (NRC fastrack?) or hopefully a bit less? then two years to build a plant (What type?) that takes us to 2024 maybe, hopefully a little less to allow for some testing maybe?
https://www.csgmidwest.org/MRMTP/documents/fall2017/RMT_MeetingProceedings_Fall2017.pdfdocument created 20/2/2018
The Council of State Governments Midwestern Radioactive Materials Transportation Committee
Proceedings of the Fall Meeting December 13-14, 2017 ● Cincinnati, Ohio
Mr. Knerr said the PPPO was established in 2002 to focus on cleanup activity at the Portsmouth and Paducah sites, specifically, D&D of legacy facilities, environmental cleanup work, and remediation of legacy burial grounds. He said, additionally, the project began working on the conversion of DOE’s inventory of DUF6 into uranium oxide and constructed two virtually identical conversion facilities, one at each site.
Mr. Knerr explained that, after 50 years of operation, the inventory of DUF6 at GDP was approximately 65,000 cylinders, all at Portsmouth and Paducah. He said they had processed some of that material, so the remaining inventory was 62,000 cylinders. He showed photos of the DUF6 cylinders and explained that the typical canister was 48 inches in diameter, approximately 12 feet long and can hold 10 tons of DUF6.
Mr. Knerr explained that the DUF6 needed to be converted because, in the event of a release, it can react with the moisture in the air and form toxic gas. He said uranium oxide, on the other hand, is an insoluble powder that does not react with either water or air.
Mr. Knerr said DOE broke ground on the two conversion facilities in 2004 and the plants began initial operations in late-2010 and early-2011. He said operations were expected to continue at the Portsmouth site until the mid-2030s and at the Paducah facility until the mid-2040s. He said, afterwards, DOE may use these facilities for processing commercial DUF6, which it is obligated to do under current law, if requested.
Mr. Knerrwent into more detail about the DUF6 conversion process. He explained that there are four production lines at Paducah and three production lines at Portsmouth, and each line has two autoclaves. He said it takes roughly 48 hours to load one cylinder into an autoclave, remove the material, and empty the cylinder, which means they are able to process one cylinder per day per line. He explained that the cylinders are the most radioactive when they come out of the autoclave, so they are placed on an aging pad for 30 to 60 days while the short-lived decay products decay. He said the cylinders are then brought back into the facility, neutralized, and modified with a flange, so they can be used to store and ship uranium oxide.
Mr. Knerr explained that the UF6, once it is removed from a cylinder, goes into a conversion unit where it is mixed with steam and hydrogen. He said, as a result, uranium oxide drops out of the conversion unit and is vacuumed into a powder hopper, while hydrogen fluoride (HF) gas rises to the top of the unit. He said when the powder hopper is full, it compacts the uranium oxide into briquettes, and then gravity feeds it into the modified cylinders. He said the hydrogen gas is condensed into a liquid, put in very large tanks, and sampled, before being loaded onto railcars or trucks for shipping offsite.
Mr. Knerr said the designed production of the two sites is 31,500 metric tons (MT) of DUF6 per year, but the maximum they have achieved is 22,000 MT per year. He said they are still working to understand the nuances of the sites and get the desired throughput. He said, at the designed production rate, they should generate 3,000 cylinders of oxide and 145 rail tank cars of HF per year.
Mr. Knerr told attendees that offsite shipments of uranium oxide can be made by rail, in modified gondola railcars, or by truck. He said since the start of conversion operations in 2011, DOE has converted approximately 4,650 cylinders. He said the goal for FY18 is to convert 1,800 cylinders.
Mr. Knerr explained that the HF byproduct was collected for commercial reuse. He said recycling is beneficial to DOE because it avoids further processing and additional commercial production, and it offsets a portion of operating costs for the plants. He said since the initial operations, the facilities have collected almost 10 million gallons of HF in 480 rail tank cars.
Mr. Knerr said that DOE continues to seek reuse opportunities for the DUF6 inventory, including processing to retrieve usable fissile uranium. He said about 40% of the DUF6 inventory is suitable for further enrichment, depending on the price of uranium and the operational costs associated with re-enrichment. He said DOE has a contract in place with a commercial company for re-enrichment, however the contract has several off-ramps and may not be viable under current market conditions. He said in the event that the sales contract does proceed, the DUF6 resulting from re-enrichment would be returned to DOE inventory at Paducah, which will extend conversion operations. He said DOE is limiting the conversion of DUF6 to the 60% that is not suitable for re-enrichment, which will take around 10 years at Portsmouth and 14 years at Paducah (versus 17 years and 27 years, respectively). Mr. Knerr said there are no plans for re-enrichment activities at this time.
Mr. Knerr explained that the NEPA process must be completed prior to initiating the transportation and disposal of converted oxide. He said Phase 1 of the process, the Programmatic Environmental Impact Statement, was completed in 1999, and Phase 2, the site-specific Final Environmental Impact Statement (FEIS), was completed in 2004. He said they were now working to complete Phase 3, a Supplemental Environmental Impact Statement (SEIS) updating the FEIS analyses to include the disposal facility WCS. He explained that the original FEIS decision excluded WCS because they were not a licensed facility at the time. He said, following the completion of the SEIS, the Project’s Records of Decision will be amended and shipment information will be finalized.
Mr. Knerr said the DUF6 project has 90 gondola cars that were previously modified to hold six cylinders of oxide each. He said it is anticipated that, once shipments begin, up to 3,000 cylinders would be shipped per year. He said a truck shipment would be able to accommodate up to two cylinders per truck.
Mr. Knerr reviewed the three potential disposal sites for the oxide cylinders that are being considered in the SEIS. He said the first, WCS in West Texas, is able to receive rail shipments. He said the next, the Nevada National Security Site (NNSS), would require trans-loading rail to truck or direct truck shipments. He said the third, EnergySolutions in Utah, can receive shipments by rail.
Mr. Knerr showed maps of the rail and truck transportation routes to the three potential disposal sites. He described additional transportation and disposal challenges, which include the NRC’s pending decision about how DUF6 should be classified (it is Class A currently, but the NRC is reevaluating and the decision may impact disposal facility requirements); the completion of performance assessments at NNSS; a moratorium in Utah on the bulk disposal of uranium oxide by the NRC; and the availability of funding for transportation and disposal activities.
Mr. Knerr talked in further detail about the potential for the sites to be used for the processing of commercial DUF6. He explained that DOE has an obligation from the USEC Privatization Act of 1995 to receive and process commercial DUF6. He said, at this time, no commercial entities have notified DOE of their intent to do this, but several have asked about cost estimates for these services. He said the known commercial inventory projections are about the same as the initial DOE inventory.
Jeffrey Moore (FRA)
asked Mr. Knerr what the anticipated timeline for rail shipping was. Mr. Knerr said it was dependent on budget, but that he would target 2024 for rail shipments so they would have enough inventory to make shipments routinely.
Ms. Janairo asked where the potential re-enrichment facility would be built. Mr. Knerr said Global Laser Enrichment (GLE) was proposing to build the facility immediately off the DOE reservation in Paducah, Kentucky. He said if that happens, cylinders from Portsmouth would be put into overpacks and shipped to that facility, and at Paducah, the plan would be for the conversion and re-enrichment facilities to abut one another. He added that GLE would be responsible for packaging and transporting the cylinders from Portsmouth to Paducah. Ms. Janairo asked if GLE would coordinate with the states, similar to how DOE would. Mr. Knerr said he would assume so, but could not speak for GLE commercially. Ms. Janairo asked if there was a reason for the two different types of cylinders. Mr. Knerr explained that, back in the day, the thin-walled cylinders were preferred, but commercial enrichers currently use thick-walled cylinders, as required by the NRC.
Ms. Janairo asked if DOE planned to coordinate with the states prior to shipping the uranium oxide. Mr. Knerr said yes, they would be very engaged with stakeholders, and offered to host another tour for the Committee..
