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S.v. Narasimhan - One of the best experts on this subject based on the ideXlab platform.

  • experience with dilute chemical decontamination in indian pressurized heavy water reactors
    Energy Procedia, 2011
    Co-Authors: S Velmurugan, Veena Subramanian V K Mittal, A L Rufus, V S Sathyaseelan, S.v. Narasimhan
    Abstract:

    Abstract Dilute Chemical Decontamination (DCD) process has been used in several full System and components of nuclear Coolant Systems to effectively remove the radioactive contaminants that causes radiation field and consequent MANREM problem. The DCD process uses chemicals in very low concentrations (millimolar) and dissolves the oxide film along with the activity incorporated in the oxide film. In DCD process operated under the regenerative mode, the chemical formulation spent in the process of oxide dissolution is replenished by passing through cation exchange columns. Finally, after achieving sufficient decontamination of the System/component, the added decontamination chemicals along with the activities and metal ions released during the process are removed by mixed bed ion exchange columns and the System is restored to normal operating condition in a few days time. In PHWRs, the regenerative DCD process is applied for full Primary Coolant System decontamination. The chemicals are added directly to the heavy water Coolant with the fuel in the core. In Indian PHWRs (MAPS#1&2, RAPS#1&2, NAPS#1&2 and KAPS#1), the process has been applied eleven times. A chemical formulation based on NTA, Citric acid and Ascorbic acid has been applied seven times with good results. Decontamination factors in the range 2-30 have been obtained in different components with good MANREM savings in the subsequent maintenance works. Efforts are on to modify the process to take care of the challenges posed by antimony isotopes. An inhibitor (Rodine-92B) based process was successfully tested in NAPS#2 for removing antimony isotopes (122Sb and 124Sb). Further refining of the antimony removal process is being worked out. Similarly, the process is being modified to effectively remove the hotspot causing stellite particles in the moderator System of PHWRs. A permanganate based process has been developed and tested in several adjustor rod drive mechanisms in KAPS and NAPS. The experience of applying/testing the DCD process in the Indian nuclear reactors is described in this paper.

  • experience with dilute chemical decontamination in indian pressurized heavy water reactors
    Energy Procedia, 2011
    Co-Authors: Soundarapandian Velmurugan, Veena Subramanian V K Mittal, A L Rufus, V S Sathyaseelan, S.v. Narasimhan
    Abstract:

    Abstract Dilute Chemical Decontamination (DCD) process has been used in several full System and components of nuclear Coolant Systems to effectively remove the radioactive contaminants that causes radiation field and consequent MANREM problem. The DCD process uses chemicals in very low concentrations (millimolar) and dissolves the oxide film along with the activity incorporated in the oxide film. In DCD process operated under the regenerative mode, the chemical formulation spent in the process of oxide dissolution is replenished by passing through cation exchange columns. Finally, after achieving sufficient decontamination of the System/component, the added decontamination chemicals along with the activities and metal ions released during the process are removed by mixed bed ion exchange columns and the System is restored to normal operating condition in a few days time. In PHWRs, the regenerative DCD process is applied for full Primary Coolant System decontamination. The chemicals are added directly to the heavy water Coolant with the fuel in the core. In Indian PHWRs (MAPS#1&2, RAPS#1&2, NAPS#1&2 and KAPS#1), the process has been applied eleven times. A chemical formulation based on NTA, Citric acid and Ascorbic acid has been applied seven times with good results. Decontamination factors in the range 2-30 have been obtained in different components with good MANREM savings in the subsequent maintenance works. Efforts are on to modify the process to take care of the challenges posed by antimony isotopes. An inhibitor (Rodine-92B) based process was successfully tested in NAPS#2 for removing antimony isotopes (122Sb and 124Sb). Further refining of the antimony removal process is being worked out. Similarly, the process is being modified to effectively remove the hotspot causing stellite particles in the moderator System of PHWRs. A permanganate based process has been developed and tested in several adjustor rod drive mechanisms in KAPS and NAPS. The experience of applying/testing the DCD process in the Indian nuclear reactors is described in this paper.

  • comparative study of nitrilo triacetic acid nta and edta as formulation constituents for the chemical decontamination of Primary Coolant Systems of nuclear power plants
    Progress in Nuclear Energy, 2004
    Co-Authors: A L Rufus, V S Sathyaseelan, Soundarapandian Velmurugan, S.v. Narasimhan
    Abstract:

    Abstract Radiation field reduction in the Primary Heat Transport (PHT) System of water cooled reactors can be achieved by `Dilute Chemical Decontamination (DCD) process' operated in regenerative mode. This process uses a mixture of dilute amino carboxylic/ carboxylic acids and reducing/ oxidizing agents to remove the oxide film and the activity deposited on the out-of-core surfaces of nuclear power reactors. Ethylene Diamine Tetra Acetic Acid (EDTA) is normally used as the main chelating agent in the chemical formulations employed. Detailed studies indicated that Nitrilo Triacetic Acid (NTA) instead of EDTA could be used as the main chelating agent. Consequently, a new chemical formulation was evolved and its oxide dissolution characteristics, corrosion compatibility of structural materials, pick-up on ion exchange resins, ion exchange capabilities, radiation stability have been evaluated and compared with the EDTA based formulation. Some studies have been carried out in heavy water as the decontamination of Primary Coolant System of Pressurized Heavy Water Reactors (PHWRs) is carried out in heavy water medium. From these studies, it has been concluded that NTA as a constituent of decontamination formulation has many advantages over EDTA for the chemical decontamination of Primary Coolant Systems of PHWRs. The new formulation can also be applied to stainless steel Systems such as PWRs and BWRs as a reducing formulation followed by an oxidation step.

A L Rufus - One of the best experts on this subject based on the ideXlab platform.

  • experience with dilute chemical decontamination in indian pressurized heavy water reactors
    Energy Procedia, 2011
    Co-Authors: S Velmurugan, Veena Subramanian V K Mittal, A L Rufus, V S Sathyaseelan, S.v. Narasimhan
    Abstract:

    Abstract Dilute Chemical Decontamination (DCD) process has been used in several full System and components of nuclear Coolant Systems to effectively remove the radioactive contaminants that causes radiation field and consequent MANREM problem. The DCD process uses chemicals in very low concentrations (millimolar) and dissolves the oxide film along with the activity incorporated in the oxide film. In DCD process operated under the regenerative mode, the chemical formulation spent in the process of oxide dissolution is replenished by passing through cation exchange columns. Finally, after achieving sufficient decontamination of the System/component, the added decontamination chemicals along with the activities and metal ions released during the process are removed by mixed bed ion exchange columns and the System is restored to normal operating condition in a few days time. In PHWRs, the regenerative DCD process is applied for full Primary Coolant System decontamination. The chemicals are added directly to the heavy water Coolant with the fuel in the core. In Indian PHWRs (MAPS#1&2, RAPS#1&2, NAPS#1&2 and KAPS#1), the process has been applied eleven times. A chemical formulation based on NTA, Citric acid and Ascorbic acid has been applied seven times with good results. Decontamination factors in the range 2-30 have been obtained in different components with good MANREM savings in the subsequent maintenance works. Efforts are on to modify the process to take care of the challenges posed by antimony isotopes. An inhibitor (Rodine-92B) based process was successfully tested in NAPS#2 for removing antimony isotopes (122Sb and 124Sb). Further refining of the antimony removal process is being worked out. Similarly, the process is being modified to effectively remove the hotspot causing stellite particles in the moderator System of PHWRs. A permanganate based process has been developed and tested in several adjustor rod drive mechanisms in KAPS and NAPS. The experience of applying/testing the DCD process in the Indian nuclear reactors is described in this paper.

  • experience with dilute chemical decontamination in indian pressurized heavy water reactors
    Energy Procedia, 2011
    Co-Authors: Soundarapandian Velmurugan, Veena Subramanian V K Mittal, A L Rufus, V S Sathyaseelan, S.v. Narasimhan
    Abstract:

    Abstract Dilute Chemical Decontamination (DCD) process has been used in several full System and components of nuclear Coolant Systems to effectively remove the radioactive contaminants that causes radiation field and consequent MANREM problem. The DCD process uses chemicals in very low concentrations (millimolar) and dissolves the oxide film along with the activity incorporated in the oxide film. In DCD process operated under the regenerative mode, the chemical formulation spent in the process of oxide dissolution is replenished by passing through cation exchange columns. Finally, after achieving sufficient decontamination of the System/component, the added decontamination chemicals along with the activities and metal ions released during the process are removed by mixed bed ion exchange columns and the System is restored to normal operating condition in a few days time. In PHWRs, the regenerative DCD process is applied for full Primary Coolant System decontamination. The chemicals are added directly to the heavy water Coolant with the fuel in the core. In Indian PHWRs (MAPS#1&2, RAPS#1&2, NAPS#1&2 and KAPS#1), the process has been applied eleven times. A chemical formulation based on NTA, Citric acid and Ascorbic acid has been applied seven times with good results. Decontamination factors in the range 2-30 have been obtained in different components with good MANREM savings in the subsequent maintenance works. Efforts are on to modify the process to take care of the challenges posed by antimony isotopes. An inhibitor (Rodine-92B) based process was successfully tested in NAPS#2 for removing antimony isotopes (122Sb and 124Sb). Further refining of the antimony removal process is being worked out. Similarly, the process is being modified to effectively remove the hotspot causing stellite particles in the moderator System of PHWRs. A permanganate based process has been developed and tested in several adjustor rod drive mechanisms in KAPS and NAPS. The experience of applying/testing the DCD process in the Indian nuclear reactors is described in this paper.

  • comparative study of nitrilo triacetic acid nta and edta as formulation constituents for the chemical decontamination of Primary Coolant Systems of nuclear power plants
    Progress in Nuclear Energy, 2004
    Co-Authors: A L Rufus, V S Sathyaseelan, Soundarapandian Velmurugan, S.v. Narasimhan
    Abstract:

    Abstract Radiation field reduction in the Primary Heat Transport (PHT) System of water cooled reactors can be achieved by `Dilute Chemical Decontamination (DCD) process' operated in regenerative mode. This process uses a mixture of dilute amino carboxylic/ carboxylic acids and reducing/ oxidizing agents to remove the oxide film and the activity deposited on the out-of-core surfaces of nuclear power reactors. Ethylene Diamine Tetra Acetic Acid (EDTA) is normally used as the main chelating agent in the chemical formulations employed. Detailed studies indicated that Nitrilo Triacetic Acid (NTA) instead of EDTA could be used as the main chelating agent. Consequently, a new chemical formulation was evolved and its oxide dissolution characteristics, corrosion compatibility of structural materials, pick-up on ion exchange resins, ion exchange capabilities, radiation stability have been evaluated and compared with the EDTA based formulation. Some studies have been carried out in heavy water as the decontamination of Primary Coolant System of Pressurized Heavy Water Reactors (PHWRs) is carried out in heavy water medium. From these studies, it has been concluded that NTA as a constituent of decontamination formulation has many advantages over EDTA for the chemical decontamination of Primary Coolant Systems of PHWRs. The new formulation can also be applied to stainless steel Systems such as PWRs and BWRs as a reducing formulation followed by an oxidation step.

V S Sathyaseelan - One of the best experts on this subject based on the ideXlab platform.

  • experience with dilute chemical decontamination in indian pressurized heavy water reactors
    Energy Procedia, 2011
    Co-Authors: S Velmurugan, Veena Subramanian V K Mittal, A L Rufus, V S Sathyaseelan, S.v. Narasimhan
    Abstract:

    Abstract Dilute Chemical Decontamination (DCD) process has been used in several full System and components of nuclear Coolant Systems to effectively remove the radioactive contaminants that causes radiation field and consequent MANREM problem. The DCD process uses chemicals in very low concentrations (millimolar) and dissolves the oxide film along with the activity incorporated in the oxide film. In DCD process operated under the regenerative mode, the chemical formulation spent in the process of oxide dissolution is replenished by passing through cation exchange columns. Finally, after achieving sufficient decontamination of the System/component, the added decontamination chemicals along with the activities and metal ions released during the process are removed by mixed bed ion exchange columns and the System is restored to normal operating condition in a few days time. In PHWRs, the regenerative DCD process is applied for full Primary Coolant System decontamination. The chemicals are added directly to the heavy water Coolant with the fuel in the core. In Indian PHWRs (MAPS#1&2, RAPS#1&2, NAPS#1&2 and KAPS#1), the process has been applied eleven times. A chemical formulation based on NTA, Citric acid and Ascorbic acid has been applied seven times with good results. Decontamination factors in the range 2-30 have been obtained in different components with good MANREM savings in the subsequent maintenance works. Efforts are on to modify the process to take care of the challenges posed by antimony isotopes. An inhibitor (Rodine-92B) based process was successfully tested in NAPS#2 for removing antimony isotopes (122Sb and 124Sb). Further refining of the antimony removal process is being worked out. Similarly, the process is being modified to effectively remove the hotspot causing stellite particles in the moderator System of PHWRs. A permanganate based process has been developed and tested in several adjustor rod drive mechanisms in KAPS and NAPS. The experience of applying/testing the DCD process in the Indian nuclear reactors is described in this paper.

  • experience with dilute chemical decontamination in indian pressurized heavy water reactors
    Energy Procedia, 2011
    Co-Authors: Soundarapandian Velmurugan, Veena Subramanian V K Mittal, A L Rufus, V S Sathyaseelan, S.v. Narasimhan
    Abstract:

    Abstract Dilute Chemical Decontamination (DCD) process has been used in several full System and components of nuclear Coolant Systems to effectively remove the radioactive contaminants that causes radiation field and consequent MANREM problem. The DCD process uses chemicals in very low concentrations (millimolar) and dissolves the oxide film along with the activity incorporated in the oxide film. In DCD process operated under the regenerative mode, the chemical formulation spent in the process of oxide dissolution is replenished by passing through cation exchange columns. Finally, after achieving sufficient decontamination of the System/component, the added decontamination chemicals along with the activities and metal ions released during the process are removed by mixed bed ion exchange columns and the System is restored to normal operating condition in a few days time. In PHWRs, the regenerative DCD process is applied for full Primary Coolant System decontamination. The chemicals are added directly to the heavy water Coolant with the fuel in the core. In Indian PHWRs (MAPS#1&2, RAPS#1&2, NAPS#1&2 and KAPS#1), the process has been applied eleven times. A chemical formulation based on NTA, Citric acid and Ascorbic acid has been applied seven times with good results. Decontamination factors in the range 2-30 have been obtained in different components with good MANREM savings in the subsequent maintenance works. Efforts are on to modify the process to take care of the challenges posed by antimony isotopes. An inhibitor (Rodine-92B) based process was successfully tested in NAPS#2 for removing antimony isotopes (122Sb and 124Sb). Further refining of the antimony removal process is being worked out. Similarly, the process is being modified to effectively remove the hotspot causing stellite particles in the moderator System of PHWRs. A permanganate based process has been developed and tested in several adjustor rod drive mechanisms in KAPS and NAPS. The experience of applying/testing the DCD process in the Indian nuclear reactors is described in this paper.

  • comparative study of nitrilo triacetic acid nta and edta as formulation constituents for the chemical decontamination of Primary Coolant Systems of nuclear power plants
    Progress in Nuclear Energy, 2004
    Co-Authors: A L Rufus, V S Sathyaseelan, Soundarapandian Velmurugan, S.v. Narasimhan
    Abstract:

    Abstract Radiation field reduction in the Primary Heat Transport (PHT) System of water cooled reactors can be achieved by `Dilute Chemical Decontamination (DCD) process' operated in regenerative mode. This process uses a mixture of dilute amino carboxylic/ carboxylic acids and reducing/ oxidizing agents to remove the oxide film and the activity deposited on the out-of-core surfaces of nuclear power reactors. Ethylene Diamine Tetra Acetic Acid (EDTA) is normally used as the main chelating agent in the chemical formulations employed. Detailed studies indicated that Nitrilo Triacetic Acid (NTA) instead of EDTA could be used as the main chelating agent. Consequently, a new chemical formulation was evolved and its oxide dissolution characteristics, corrosion compatibility of structural materials, pick-up on ion exchange resins, ion exchange capabilities, radiation stability have been evaluated and compared with the EDTA based formulation. Some studies have been carried out in heavy water as the decontamination of Primary Coolant System of Pressurized Heavy Water Reactors (PHWRs) is carried out in heavy water medium. From these studies, it has been concluded that NTA as a constituent of decontamination formulation has many advantages over EDTA for the chemical decontamination of Primary Coolant Systems of PHWRs. The new formulation can also be applied to stainless steel Systems such as PWRs and BWRs as a reducing formulation followed by an oxidation step.

Veena Subramanian V K Mittal - One of the best experts on this subject based on the ideXlab platform.

  • experience with dilute chemical decontamination in indian pressurized heavy water reactors
    Energy Procedia, 2011
    Co-Authors: Soundarapandian Velmurugan, Veena Subramanian V K Mittal, A L Rufus, V S Sathyaseelan, S.v. Narasimhan
    Abstract:

    Abstract Dilute Chemical Decontamination (DCD) process has been used in several full System and components of nuclear Coolant Systems to effectively remove the radioactive contaminants that causes radiation field and consequent MANREM problem. The DCD process uses chemicals in very low concentrations (millimolar) and dissolves the oxide film along with the activity incorporated in the oxide film. In DCD process operated under the regenerative mode, the chemical formulation spent in the process of oxide dissolution is replenished by passing through cation exchange columns. Finally, after achieving sufficient decontamination of the System/component, the added decontamination chemicals along with the activities and metal ions released during the process are removed by mixed bed ion exchange columns and the System is restored to normal operating condition in a few days time. In PHWRs, the regenerative DCD process is applied for full Primary Coolant System decontamination. The chemicals are added directly to the heavy water Coolant with the fuel in the core. In Indian PHWRs (MAPS#1&2, RAPS#1&2, NAPS#1&2 and KAPS#1), the process has been applied eleven times. A chemical formulation based on NTA, Citric acid and Ascorbic acid has been applied seven times with good results. Decontamination factors in the range 2-30 have been obtained in different components with good MANREM savings in the subsequent maintenance works. Efforts are on to modify the process to take care of the challenges posed by antimony isotopes. An inhibitor (Rodine-92B) based process was successfully tested in NAPS#2 for removing antimony isotopes (122Sb and 124Sb). Further refining of the antimony removal process is being worked out. Similarly, the process is being modified to effectively remove the hotspot causing stellite particles in the moderator System of PHWRs. A permanganate based process has been developed and tested in several adjustor rod drive mechanisms in KAPS and NAPS. The experience of applying/testing the DCD process in the Indian nuclear reactors is described in this paper.

  • experience with dilute chemical decontamination in indian pressurized heavy water reactors
    Energy Procedia, 2011
    Co-Authors: S Velmurugan, Veena Subramanian V K Mittal, A L Rufus, V S Sathyaseelan, S.v. Narasimhan
    Abstract:

    Abstract Dilute Chemical Decontamination (DCD) process has been used in several full System and components of nuclear Coolant Systems to effectively remove the radioactive contaminants that causes radiation field and consequent MANREM problem. The DCD process uses chemicals in very low concentrations (millimolar) and dissolves the oxide film along with the activity incorporated in the oxide film. In DCD process operated under the regenerative mode, the chemical formulation spent in the process of oxide dissolution is replenished by passing through cation exchange columns. Finally, after achieving sufficient decontamination of the System/component, the added decontamination chemicals along with the activities and metal ions released during the process are removed by mixed bed ion exchange columns and the System is restored to normal operating condition in a few days time. In PHWRs, the regenerative DCD process is applied for full Primary Coolant System decontamination. The chemicals are added directly to the heavy water Coolant with the fuel in the core. In Indian PHWRs (MAPS#1&2, RAPS#1&2, NAPS#1&2 and KAPS#1), the process has been applied eleven times. A chemical formulation based on NTA, Citric acid and Ascorbic acid has been applied seven times with good results. Decontamination factors in the range 2-30 have been obtained in different components with good MANREM savings in the subsequent maintenance works. Efforts are on to modify the process to take care of the challenges posed by antimony isotopes. An inhibitor (Rodine-92B) based process was successfully tested in NAPS#2 for removing antimony isotopes (122Sb and 124Sb). Further refining of the antimony removal process is being worked out. Similarly, the process is being modified to effectively remove the hotspot causing stellite particles in the moderator System of PHWRs. A permanganate based process has been developed and tested in several adjustor rod drive mechanisms in KAPS and NAPS. The experience of applying/testing the DCD process in the Indian nuclear reactors is described in this paper.

Soundarapandian Velmurugan - One of the best experts on this subject based on the ideXlab platform.

  • experience with dilute chemical decontamination in indian pressurized heavy water reactors
    Energy Procedia, 2011
    Co-Authors: Soundarapandian Velmurugan, Veena Subramanian V K Mittal, A L Rufus, V S Sathyaseelan, S.v. Narasimhan
    Abstract:

    Abstract Dilute Chemical Decontamination (DCD) process has been used in several full System and components of nuclear Coolant Systems to effectively remove the radioactive contaminants that causes radiation field and consequent MANREM problem. The DCD process uses chemicals in very low concentrations (millimolar) and dissolves the oxide film along with the activity incorporated in the oxide film. In DCD process operated under the regenerative mode, the chemical formulation spent in the process of oxide dissolution is replenished by passing through cation exchange columns. Finally, after achieving sufficient decontamination of the System/component, the added decontamination chemicals along with the activities and metal ions released during the process are removed by mixed bed ion exchange columns and the System is restored to normal operating condition in a few days time. In PHWRs, the regenerative DCD process is applied for full Primary Coolant System decontamination. The chemicals are added directly to the heavy water Coolant with the fuel in the core. In Indian PHWRs (MAPS#1&2, RAPS#1&2, NAPS#1&2 and KAPS#1), the process has been applied eleven times. A chemical formulation based on NTA, Citric acid and Ascorbic acid has been applied seven times with good results. Decontamination factors in the range 2-30 have been obtained in different components with good MANREM savings in the subsequent maintenance works. Efforts are on to modify the process to take care of the challenges posed by antimony isotopes. An inhibitor (Rodine-92B) based process was successfully tested in NAPS#2 for removing antimony isotopes (122Sb and 124Sb). Further refining of the antimony removal process is being worked out. Similarly, the process is being modified to effectively remove the hotspot causing stellite particles in the moderator System of PHWRs. A permanganate based process has been developed and tested in several adjustor rod drive mechanisms in KAPS and NAPS. The experience of applying/testing the DCD process in the Indian nuclear reactors is described in this paper.

  • comparative study of nitrilo triacetic acid nta and edta as formulation constituents for the chemical decontamination of Primary Coolant Systems of nuclear power plants
    Progress in Nuclear Energy, 2004
    Co-Authors: A L Rufus, V S Sathyaseelan, Soundarapandian Velmurugan, S.v. Narasimhan
    Abstract:

    Abstract Radiation field reduction in the Primary Heat Transport (PHT) System of water cooled reactors can be achieved by `Dilute Chemical Decontamination (DCD) process' operated in regenerative mode. This process uses a mixture of dilute amino carboxylic/ carboxylic acids and reducing/ oxidizing agents to remove the oxide film and the activity deposited on the out-of-core surfaces of nuclear power reactors. Ethylene Diamine Tetra Acetic Acid (EDTA) is normally used as the main chelating agent in the chemical formulations employed. Detailed studies indicated that Nitrilo Triacetic Acid (NTA) instead of EDTA could be used as the main chelating agent. Consequently, a new chemical formulation was evolved and its oxide dissolution characteristics, corrosion compatibility of structural materials, pick-up on ion exchange resins, ion exchange capabilities, radiation stability have been evaluated and compared with the EDTA based formulation. Some studies have been carried out in heavy water as the decontamination of Primary Coolant System of Pressurized Heavy Water Reactors (PHWRs) is carried out in heavy water medium. From these studies, it has been concluded that NTA as a constituent of decontamination formulation has many advantages over EDTA for the chemical decontamination of Primary Coolant Systems of PHWRs. The new formulation can also be applied to stainless steel Systems such as PWRs and BWRs as a reducing formulation followed by an oxidation step.