Contents Issue 01 (2001)

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Eric Maughan

Demineralisation of Water and the Elimination of TOC

Designing and operating makeup water installations, focus is not only on the removal of suspended and inorganic raw water constituents but also on the removal of organics. The design of the makeup water treatment plant must be carefully planned so that problems with organics are not created in other stages of the process since some water treatment processes may release organic matter into the product water. Even ion exchange resins are a source of organic contamination. However with correct tretment management, this may be controlled. A combination of membrane and ion exchange technologies will produce a high quality water with respect to both residual inorganic and organic compounds.

[ppchem Issue No. 01 (2001)]

Hartmut Grupp

Monitoring of Used Oils and Fire-Resistant Fluids in Turbine Installations

For the lubricants employed in power station operation, there have, in the past, only been a few specifications, which can be used for selecting both the lubricating oil and the control fluids. An attempt has, for the first time, been made to establish parameters for the monitoring of turbine oils and fire-resist-ant fluids and to define warning values. In addition, mea-sures are provided with respect to cause and remedy. These values have been worked out in agreement among mineral oil manufacturers, turbine manufacturers, power station operators, and independent research institutes.

[ppchem Issue No. 01 (2001)]

Thomas Klasen and Klaus Görner

The Influence of Furnace Geometry and Wall Materials on the Combustion Process and the Prediction of Problem Areas in Waste Incinerators

Based on the CFD-code FLUENT®, theoretical studies were conducted of the influences of incineration chamber geometry (direct, countercurrent and center flow) on the combustion process. The boundary conditions, e.g., the thermal input and the waste grate, were kept constant. Close attention was paid to the distribution of flow, species, and temperatures. In addition, the influence of a dis-placement body at the end of the combustion chamber was tested. The variation of different wall materials and the prediction of problem areas concerning corrosion, slagging, and contamination completed the studies. Close to the chamber walls, high CO-concentrations may indi-cate corrosion; particle flow may indicate where contami-nation, slagging or erosion could occur.

[ppchem Issue No. 01 (2001)]

Kamal Kishore, Puspalata Rajesh, Ghasi R. Dey, and Ashok G. Kumbhar

A Dilute Chemical Decontaminant Formulation Containing Gallic Acid as a Reductant

Gallic acid (GA) was tried as a reductant in place of ascorbic acid in dilute chemical decontaminant (DCD) formulations. Dissolution of magnetite in GA based DCD formulations was studied at 50 °C as well as 80 °C. It was found to be a good substitute for ascorbic acid in EDTA/ascorbic acid /citric acid, i.e., EAC formulation. The efficiency of EDTA/GA/CA formulation was as good as that of EAC formulation. 2.8 was found to be the optimum pH for this formulation and dissolution decreased at lower as well as higher pHs. The ion exchange behaviour of GA is also appropriate for using it in a regenerating type of formulation. Being an aromatic compound, Gallic acid has inherent stability against radiation degradation.

[ppchem Issue No. 01 (2001)]

Dennis Aspden and Ken J. Galt

Key Factors for a Successful Cycle Chemistry Programme

Visibility conditions in reactor wells and fuel pools of boiling water reactors do not normally cause any problems in German units. In particular cases, visibility and filter problems may occur during decommissioning or occasionally in units with pressurized water reactors. In the KRB Unit A, unexpected visibility trouble has appeared on decommissioning conditions. Turbidity has been the reason for the poor visibility. Because of this, decommissioning work has been hindered. Report on attempts to solve this problem is presented. In the end, ozone has proven to be a best remedy.

[ppchem Issue No. 01 (2001)]

W. T. Lindsay, Jr.

Partitioning of Volatile Solutes in Steam Generating Apparatus

The partitioning process for volatile solutes in steam generating apparatus is examined. Thermodynamic and mass transfer limitations on vapor/liquid equilibrium are reviewed. Muss balance equations are developed to relate internal vapor/liquid concentration ratios for recirculating steam generators to steam and blowdown concentrations. Example calculations compare the partitioning of ammonia and ethanolamine in a pressurized water reactor steam generator treated with typical feedwater concentrations. A method is suggested for determining the extent of vapor/liquid equilibration in steam generating apparatus.

[ppchem Issue No. 01 (2001)]