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Fusion Science and Technology
Latest News
Norway’s Halden reactor takes first step toward decommissioning
The government of Norway has granted the transfer of the Halden research reactor from the Institute for Energy Technology (IFE) to the state agency Norwegian Nuclear Decommissioning (NND). The 25-MWt Halden boiling water reactor operated from 1958 to 2018 and was used in the research of nuclear fuel, reactor internals, plant procedures and monitoring, and human factors.
Hiroo Numata, Izumi Ohno
Fusion Science and Technology | Volume 38 | Number 2 | September 2000 | Pages 206-223
Technical Paper | doi.org/10.13182/FST00-A143
Articles are hosted by Taylor and Francis Online.
The physicochemical properties of the Pd-H system were studied by in situ potentiometric, resistance, and dilatometric measurements in each of three applied pulse modes, A, B, and C, and repeated H absorption and desorption. Potential, resistance ratio, and an increase in dilation (l/l0) were measured simultaneously after H equilibrium was attained with the Pd electrode. During continuous absorption, structural phase transition ( [right arrow] ) and void formation occurred, and the values of the H/Pd ratio in the limiting phase, in the + phase coexistence, and in the transition and the +voids coexistence regions are consistent with those obtained from the Pd-H isotherm at 40°C. Hydrogen absorption caused the dilation, from whose slope the molar volume was obtained as 0.64 ( phase) and 0.40 ( + phase) cm3/mol. The resistance increased in proportion to the H/Pd ratio and was kept constant at 1.7 to 1.8 over Rtr.For the first absorption through the phase (>min), the electrode potential shifted with an increase in dilation, which suggests nonequilibrium PdH2-x precipitation followed by conversion to the phase and void formation. Although there was a remarkable lack of any dependence on the number of repetitions of the values of the limiting resistance and potential corresponding to the + and + void coexistence, the onset of the phase, min, increased as the number of repetitions increased. The volumetric ratio for an increase in the H/Pd ratio corresponds to the absorption in high-density defect areas surrounding voids. During repeated absorption and desorption in the C applied pulse mode, the apparent molar volumes of the + phase coexistence show that absorption proceeds inhomogenously, in contrast to the first absorption in the A applied pulse mode.
