Pulsed Versus Steady-State Reactor Operation in View of Safety and Economy

The degradation of 2,4,6,-trichlorophenol (2,4,6-TCP), 2,3,4,6-tetra-chlorophenol (2,3,4,6-TeCP) and pentachlorophenol (PCP) was evaluated in oxic fluidized-bed reactors. The pseudo-steady-state reactor operation at a hydraulic retention time of 5 hours and feed concentrations of 54 mg/l of 2,4,6-TCP and 64 mg/l of 2,3,4,6-TeCP resulted in stable and effective removal performances on these compounds. GC/MS results indicated over 99 % removal of both 2,4,6-TCP and 2,3,4,6-TeCP. However, PCP degradation at 74 mg/l feed concentration was neglible under these conditions. Further, a denitrifying biofilm was developed which was able to use 4-chlorophenol (4-CP) as the sole electron donor in denitrification reactions. No anoxie biofilm able to degrade 2,4-dichlorophenol (2,4-DCP) or PCP degradation in the presence of potassium nitrate could be developed.

Download Full-text

Radioactivity computation of steady state and pulsed fusion reactor operation

Fusion Engineering and Design ◽

10.1016/0920-3796(95)90085-3 ◽

1995 ◽

Vol 28 ◽

pp. 571-578 ◽

Cited By ~ 5

Author(s):

Hosny Attaya

Keyword(s):

Steady State ◽

Fusion Reactor ◽

Reactor Operation

Download Full-text

NEUTRONIC AND THERMAL HYDRAULICS ANALYSIS OF CONTROL ROD EFFECT ON THE OPERATION SAFETY OF TRIGA 2000 REACTOR

Urania Jurnal Ilmiah Daur Bahan Bakar Nuklir ◽

10.17146/urania.2019.25.3.5576 ◽

2019 ◽

Vol 25 (3) ◽

Author(s):

Surian Pinem ◽

Tukiran Surbakti ◽

Iman Kuntoro

Keyword(s):

Steady State ◽

Thermal Hydraulics ◽

Reactor Operation ◽

Control Rod ◽

Active Core ◽

Reactivity Coefficients ◽

Calculation Results ◽

Reactivity Coefficient ◽

Operation Cycle ◽

Control Rods

NEUTRONIC AND THERMAL HYDRAULICS ANALYSIS OF CONTROL ROD EFFECT ON THE OPERATION SAFETY OF TRIGA 2000 REACTOR. Analysis of neutronic and thermal-hydraulics parameters of whole operation cycle is very important for the safety of reactor operation. During the reactor operation cycle, the position of the control rods will change due to reactivity changes. The purpose of this study is to determine the effect of control rods position on neutronic and thermal-hydraulics parameters in relation to the safety of reactor operation of the TRIGA 2000 reactor using silicide fuel of MTR plate type. Those parameters are power peaking factor, reactivity coefficients, and steady-state thermohydraulic parameters. Neutronic calculations are performed using a combination of WIMSD/5 and Batan-3DIFF codes and for thermal-hydraulics the calculations are done using WIMSD/5 and MTRDYN codes. The calculation results show that the reactivity coefficient values are negative for all control rod positions both at CZP and HFP conditions. The MTC value decreases when the control rod is inserted into the active core while the FTC value increases. The total ppf results and temperature in steady-state rise when the control rods are inserted of into the active core whereby the maximum value occurs at the position of the control rods of 20 cm from the bottom of the active core. The calculation results of ppf, reactivity coefficient, and thermal-hydraulics parameters lay below safety limits, indicating that the TRIGA 2000 reactor can safely use U3Si2-Al silicide fuel as a substitute fuel for cylindrical type fuel.Keywords: neutronic, thermal-hydraulic parameter, control rod effect, TRIGA 2000, silicide fuel.

Download Full-text

Studies on Water in the Hydration Chamber of a Modified Electron Microscope

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100069715 ◽

1970 ◽

Vol 28 ◽

pp. 544-545

Author(s):

R. C. Moretz ◽

G. G. Hausner ◽

D. F. Parsons

Keyword(s):

Thin Film ◽

Thin Films ◽

Electron Microscope ◽

Steady State ◽

Room Temperature ◽

Small Mass ◽

Equilibrium Pressure ◽

Biological Objects ◽

Mechanical Pump ◽

Differential Pumping

Use of the electron microscope to examine wet objects is possible due to the small mass thickness of the equilibrium pressure of water vapor at room temperature. Previous attempts to examine hydrated biological objects and water itself used a chamber consisting of two small apertures sealed by two thin films. Extensive work in our laboratory showed that such films have an 80% failure rate when wet. Using the principle of differential pumping of the microscope column, we can use open apertures in place of thin film windows.Fig. 1 shows the modified Siemens la specimen chamber with the connections to the water supply and the auxiliary pumping station. A mechanical pump is connected to the vapor supply via a 100μ aperture to maintain steady-state conditions.

Download Full-text

Continuous hydrogenolysis of acetal-stabilized lignin in flow

Green Chemistry ◽

10.1039/d0gc02928a ◽

2021 ◽

Author(s):

Wu Lan ◽

Yuan Peng Du ◽

Songlan Sun ◽

Jean Behaghel de Bueren ◽

Florent Héroguel ◽

...

Keyword(s):

Steady State ◽

Challenges And Opportunities

We performed a steady state high-yielding depolymerization of soluble acetal-stabilized lignin in flow, which offered a window into challenges and opportunities that will be faced when continuously processing this feedstock.

Download Full-text