Continuous-Operation Test at Engineering Scale Uranium Crystallizer System

Author(s):  
Tadahiro Washiya ◽  
Toshimitsu Tayama ◽  
Kazuhito Nakamura ◽  
Kimihiko Yano ◽  
Atsuhiro Shibata ◽  
...  

Uranium crystallization based on solubility difference is one of the remarkable technologies which can provide simple process to separate uranium in nitric acid solution since the process is mainly controlled by temperature and concentration of solute ions. Japan Atomic Energy Agency (JAEA) and Mitsubishi Materials Corporation (MMC) are developing the crystallization process for elemental technology of FBR fuel reprocessing.[1–3] The uranium (U) crystallization process is a key technology for New Extraction System for TRU Recovery (NEXT) process that was evaluated as the most promising process for future FBR reprocessing.[4–6] We had developed an innovative crystallizer and carried out several fundamental investigations. On the basis of the results, we fabricated an engineering-scale crystallizer and have carried out continuous operation test to investigate the stability of the equipment at steady and non-steady state conditions by using depleted uranium. As for simulating typical failure events in the crystallizer, crystal accumulation and crystal blockage were occurred intentionally, and monitoring method and resume procedure were tried and selected in this work. As the test results, no significant phenomenon was observed in the steady state test. And in the non-steady state test, process fluctuation could be detected by monitoring of screw torque and liquid level in the crystallizer, and all failure events are proven to be recovered by appropriate resumed procedures.

2001 ◽  
Author(s):  
M. Auriemma ◽  
F. E. Corcione ◽  
S. Diana ◽  
G. Police ◽  
G. Valentino

Author(s):  
Takao Kondo ◽  
Kazuaki Kitou ◽  
Masao Chaki ◽  
Yukiharu Ohga ◽  
Takeshi Makigami

Japanese national project of next generation light water reactor (LWR) development started in 2008. Under this project, spectral shift rod (SSR) is being developed. SSR, which replaces conventional water rod (WR) of boiling water reactor (BWR) fuel bundle, was invented to enhance the BWR’s merit, spectral shift effect for uranium saving. In SSR, water boils by neutron and gamma-ray direct heating and water level is formed as a boundary of the upper steam region and the lower water region. This SSR water level can be controlled by core flow rate, which amplifies the change of average core void fraction, resulting in the amplified spectral shift effect. This paper presents the steady state test with varied SSR geometry parameters, the transient test, and the simulation analysis of these steady state and transient tests. The steady state test results showed that the basic functioning principle such as the controllability of SSR water level by flow rate was maintained in the possible range of geometry parameters. The transient test results showed that the change rate of SSR water level was slower than the initiating parameters. The simulation analysis of steady state and transient test showed that the analysis method can simulate the height of SSR water level and its change with a good agreement. As a result, it is shown that the SSR design concept and its analysis method are feasible in both steady state and transient conditions.


2006 ◽  
Vol 1 (3) ◽  
pp. 222-232 ◽  
Author(s):  
Oliver Faude ◽  
Tim Meyer ◽  
Wilfried Kindermann

Purpose:The work rate (WR) corresponding to ventilatory threshold (VT) is an appropriate intensity for regenerative and low-intensity training sessions. During incremental ramp exercise, VO2 increase lags behind WR increase. Traditionally, a VO2 time delay (td) of 45 seconds is used to calculate the WR at VT from such tests. Considerable inaccuracies were observed when using this constant td. Therefore, this study aimed at reinvestigating the temporal relationship between VO2 and WR at VT.Methods:20 subjects (VO2peak 49.9 to 72.6 mL · min–1 · kg–1) performed a ramp test in order to determine VT and a subsequent steady-state test during which WR was adjusted to elicit the VO2 corresponding to VT. The difference in WR and heart rate at VT was calculated between the ramp and the steady-state test (WRdiff, HRdiff) as well as the time delay corresponding to WRdiff during ramp exercise.Results:Mean values were td = 85 ± 26 seconds (range 38 to 144), WRdiff = 45 ± 12 W (range 23 to 67), HRdiff = 1 ± 9 beats/min (range –21 to +15). The limits of agreement for the difference between WR at VT during ramp and steady-state exercise were ± 24 W. No signifi cant influence on td, WRdiff, or HRdiff from differences in endurance capacity (VO2peak and VT; P > .10 for all correlations) or ramp increment (P = .26, .49, and .85, respectively) were observed.Conclusion:The wide ranges of td, WRdiff, and HRdiff prevent the derivation of exact training guidelines from single-ramp tests. It is advisable to perform a steady-state test to exactly determine the WR corresponding to VT.


2008 ◽  
Vol 23 (2) ◽  
pp. 87-90 ◽  
Author(s):  
G.J. Olcina ◽  
R. Timón ◽  
D. Muñoz ◽  
J.I. Maynar ◽  
M.J. Caballero ◽  
...  

1999 ◽  
Vol 75 (7) ◽  
pp. 842-853 ◽  
Author(s):  
Ryuhei KUMAZAWA ◽  
Takashi MUTOH ◽  
Tetsuo SEKI ◽  
Fujio SHINPO ◽  
Gorou NOMURA ◽  
...  

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