Drying results of K-Basin fuel element 0309M (Run 3)
[report]
B.M. Oliver, G.S. Klinger, J. Abrefah, S.C. Marschman, P.J. MacFarlan, G.A. Ritter
1998
unpublished
An N-Reactor outer fuel element that had been stored underwater in the Hanford 100 Area K-West Basin was subjected to a combination of low-and high-temperature vacuum drying treatments. These studies are part of a series of tests being conducted by Pacific Northwest National Laboratory on the drying behavior of spent nuclear fuel elements removed from both the K-West and K-East Basins. The drying test series was designed to test fuel elements that ranged from intact to severely damaged. The
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... element discussed in this report was removed from K-West canister 0309M during the second fuel selection campaign, conducted in 1996, and has remained in wet storage in the Postirradiation Testing Laboratory (PTL, 327 Building) since that time. The fuel element was broken in two pieces, with a relatively clean fracture, and the larger piece was tested. A gray/white coating was observed. This was the first test of a damaged fuel element in the furnace. K-West canisters can hold up to seven complete fuel assemblies, but, for purposes of this report, the element tested here is designated as Element 0309M. The drymg test was conducted in the Whole Element Furnace Testing System located in G-Cell within the PTL. The test system is composed of three basic systems: the in-cell furnace equipment, the system gas loop, and the analytical instrument package. Element 0309M was subjected to drymg processes based on those proposed under the Integrated Process Strategy, which included a hot drying step. The test cycles are listed below: Vacuum Drying (CVD) at -50°C under vacuum (-0.7 hr) 0 Pressure Rise Tests (2) at -5OOC (-2 hr) 0 Hot Vacuum Drying (HVD) for a total of 59 hr (-17 hr at -80°C, -34 hr at -80°C to -400°C, and -8 hr at -4OOOC) System Cooldown to -5OOC (-29 hr) Post-Test Pressure Rise Test at -5OOC (-1 hr). Approximately 5 ml of water were observed in the condenser during the condenser pumpdown phase of CVD. Two Pressure Rise Tests were conducted following CVD. The first Pressure Rise Test did not meet the criterion of d . 6 T o r r h and, therefore, a second test was successfully conducted. Approximately 4 mg of water were removed during both Pressure Rise Tests, likely fromfiee water, trapped under the observed surface coating on the fuel element, which was not completely released during CVD. Approximately 2 g of water were released during HVD, with the largest amount (-1.7 g) removed during the temperature increment from -8OOC to -4OOOC. Thermal decomposition of hydrated species was significant in controlling the removal of water from the system during the HVD. As a result, a temperature above 400°C may be required for complete drying of the hydrated species within a reasonable period of time. iii Hydrogen was also observed during HVD starting at about 1 5OoC. Two main peaks were evident, at -222OC fiom oxidation of the fuel by water, and at -270OC fiom the decomposition of uranium hydride. Total hydrogen release during HVD was -19 mg. iv Quality Assurance This work was conducted under the Quality Assurance Program, Pacific Northwest National Laboratory (PW) SNF-70-00 1 , SNF Quality Assurance Program, as implemented by the PNNL SNF Characterization Project Operations Manual. This QA program has been evaluated and determined to effectively implement the requirements of DOE RW-O333P, Office of Civilian Radioactive Waste Management Quality Assurance Requirements and Description (QARD). Compliance with the QARD is mandatory for projects which generate data used to support the development of a permanent High-Level Nuclear Waste repository. Further, the U.S. Department of Energy has determined that the testing activities which generated the results documented in this report shall comply with the QARD. Supporting records for the data in this report are located in the permanent PNNL SNF Characterization Project records, Furnace Testing of SNF Fuel Element 0309M V
doi:10.2172/291179
fatcat:utxms42edjbmpnuwbe7fzesmdy