Radioactive Waste Management & Conditioning

Continuous efforts to develop new technologies and to improve the existing ones

Wox

Background

A number of radioactive organic waste are generated from the operation of NPP; in this context the spent resins, used to remove radioactive nuclides and chemical impurities from the water clean-up systems, represent a form of Low and Intermediate Level Waste demanding special precautions when

processed and conditioned.

Our Solution

Ansaldo Nucleare and Granit Technologies (an Ansaldo Nucleare's Swiss partner) are developing a technology to treat radioactive organic waste based on a Wet Oxidation Process. The project entails experimentation on a Pilot plant and it' s specifically applied for treatment of spent ion exchange resins produced in Trino NPP (Italy).

The process is based on a chemical reaction that takes place in the liquid state, consisting of the oxidation of organic and inorganic substances through the use of oxygen at high temperature and high pressure. The reaction, which doesn't require any catalyst, transforms organic material into water and carbon oxide and the inorganic component into mineral oxides without producing toxic emission of gases, sulphur dioxide, nitrogen oxides or carbon monoxide.

After wet oxidation treatment, inorganic residues can be conditioned for disposal.

The WOT project on Trino NPP includes the following system sections:

  • Pre-treatment: recovery of exhausted resins, including extraction from purifier vessels, dewatering and grinding.
  • Wet oxidation treatment: the "core process" which transforms organic material into water and CO2 and inorganic material into insoluble oxides.
  • Post-treatment: final treatment to condition solid residue containing radioactive contamination and process solution containing soluble salts.

Trino WOT project also includes building ventilation, and drainage systems adaptation in order to set the WOT complete system.

Why choose WOX?

  • Reduction of final waste volume, saving disposal capacity and costs;
  • Conditioning of the radioactive waste into a stable solid form for final disposal;
  • Deploying technologies used in other industrial fields, after proper adaptation to nuclear requirements (our wet oxidation process technology has been dedicated to date, to industrial and urban waste treatment); 
  • Propose valid alternative to the current practices

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Phadec

Background

Thousands of tonnes of radioactive steel scrap parts are produced during nuclear plant decommissioning and dismantling.  If all of these steel scraps had to be stored the costs would be unbearable. Some of these steel scraps, instead of being packed and stored in Interim or long term repository, can be decontaminated, as most of the radioactivity runs just a few microns deep into the material. 

Our Solution

We are committed to the development and optimization of processes for the off-line decontamination of metal waste from dismantling, in order to declassify this lower level waste and finally reduce the volume of material that needs to be stored, providing a significant costs saving for its clients.

We have selected and developed in partnership with Babcock Noell GmbH a technology that is based on the Phosphoric Acid Decontamination  (PHADEC).

Ansaldo Nucleare and Babcock Noell GmbH have successfully installed and commissioned a PHADEC facility at CAORSO NPP in Piacenza (Italy) to decontaminate materials from the Reactor Building dismantling.   The facility represents the second application at industrial scale of this off-line decontamination process (the first-of-a-kind plant is still in operation at KRB plant in Gundremmingen).

The process consists of:

  • a Decontamination Unit (DU), in which phosphoric acid solution performs a chemical and electro-chemical decontamination of steel scraps,
  • a Regeneration Section (RS), where the dissolved iron is removed from the acid solution.   This leaves concentrated phosphoric acid ready to be used again and allows significant reduction of the secondary waste generation.

Why choose PHADEC?

  • Reduction of final waste volume, meaning less nuclear waste storage is needed and costs are lowered;
  • Low production of secondary waste because phosphoric acid solution is regenerated and reused;
  • Lower environmental impact as dismantled parts are decontaminated;
  • Minimised nuclear radiation exposure for operators

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CEMEX

​The CEMEX nuclear facility consists basically of a reinforced concrete process  building hosting systems and structures for the cementation of liquid wastes (ILW) currently stored at EUREX Nuclear Facility (operator SOGIN) and a reinforced concrete building dedicated to the interim storage of the ILW cemented packages. The scope of the project is to support the Client during the detailed design and construction phases of the nuclear facility.

Engineering support was focused on nuclear-safety issues and on setting of the project in accordance with applicable safety regulations and standards.

The above task has been made through the appointment of a Project Engineering Manager interfacing with Client staff to support the preparation of project documentation and coordinating the ANN specialists supporting this effort.

This technical support is mainly dedicated on project activities related to the following major systems:

  • Radioactive fluid process systems (piping, line components, instrumentation, tanks etc. ...);
  • Heating system, ventilation and air conditioning (HVAC);
  • Handling / lifting of the radioactive packages (roller conveyors, SAS, hoists, overhead cranes and associated equipment);

Andreeva Bay LRWMF (Liquid Radioactive Waste Management Facilities)

The project includes:

    • The Basic Design of the LWMF (Liquid Waste Management Facility) up to the design of connections between facilities and site general services, including all the necessary systems, equipment and components to realize the interfaces
    • The DDA (Design Documentation for Licensing), derived from the related Basic Design for LWMF, according to Russian laws, norms and standards.  It is included in this task the support for the state expertise review up to the release of the construction license.
    • The Basic Design of the SWMF (Solid Waste Management Facility) up to the design of connections between facilities and site general services, including all the necessary systems, equipment and components to realize the interfaces
    • The DDA (Design Documentation for Licensing), derived from the related Basic Design for SWMF, according to Russian laws, norms and standard. It is included in this task the support for the state expertise review up to the release of the construction license.
    • The Basic Design of the PTSF (Temporary Storage Facility) up to the design of connections, between facilities and site general services including all the necessary systems, equipment and components to realize the interfaces.
    • The DDA (Design Documentation for Licensing), derived from the related Basic Design for PTSF, according to Russian laws, norms and standard. It is included in this task the support for the state expertise review up to the release of the construction license.
    • For all Facilities Purchasing Technical Specification have been developed and a preliminary Tender for each equipment has been launched, a potential supplier has been identified, so completing all necessary tasks for subsequent final tender process and relevant purchasing of all material and components.
    • On the bases of the Tender's feedbacks and additional engineering evaluations, a detailed cost estimation for each Facility has been set-up including equipment, material, installation, commissioning and operation.

Ansaldo Nucleare was the Main Contractor, with Techint and Atomstroyexport (ASE) nominated sub-Contractor on Italian and Russian sides respectively.


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