National Report of The Slovak Republic , september 2001

Predchádzajúca kapitolaPredchádzajúca stranaOBSAHNasledujúca stranaNasledujúca kapitola RAW Conditioning Center at Bohunice.

The Bohunice Conditioning Center processes RAW that may be classified under the following categories:

  • combustible solid and liquid wastes,
  • compactable solid wastes,
  • incombustible and non- compactable wastes,
  • concentrates,
  • ionex resins,
  • other contaminated liquids and sludge's.

BSC includes the following technologies for RAW treatment and conditioning:

  • evaporator (concentration equipment),
  • cementation line,
  • sorting,
  • incinerator,
  • storage and transport equipment,
  • pressroom.     Evaporator.

The concentration equipment receives liquid incombustible RAW from NPP A-1, NPP V-1, NPP V-2, concentrates them and forwards them to cementation line.

The very evaporator is of the flow-through type, and comprises 3 U-shaped units. The capacity of the evaporator is 500 dm3/h for a salt contents of the wastes of 200
¸ 300 g/l.

The bride condensate is used to rinse equipment or in the incinerator flue gases cleaning system, and/or is discharged to the environment after having been cleaned at the cleaning station in building 41 or 809.

The output product - the concentrate is collected in a tank wherefrom it is transported into the cementation plant.     Cementation line.

RAW enter the dosage tank of the cementation line either directly (concentrates) from the concentration plant or through inlet containers (resins - ionex and/or sludge).

RAW from the dosage tank or ashes from incinerator’s dosing container are dosed according to proven formulations, auxiliary materials and cement are added to inclined mixer (with a volume of 500 dm3).

After thorough mixing, the cement product is poured into a high-integrity concrete container (with a volume of 3 m3). Six batches of the inclined mixer are needed to fill the container. Containers with aged and hardened cement are closed and, having been verified , they are transported to the National Repository at Mochovce. Containers with bitumen embedded products in drums and/or solid RAW pellets need 3 batches of inclined mixer to fill the empty space of the container.     Segregation.

Unsorted solid RAW are transported:

  • as loose particles in foil,
  • in 200 dm3 sacks,
  • in 200 dm3 barrels

to the segregation room, segregation box.

RAW sorted in the box are packed into 200 dm3 drums, and are transported according to its classification as follows:

  • incombustible compactable RAW into pressroom to be compacted,
  • incombustible non-compactable RAW to be directly deposited into FCC,
  • combustible, packed in 15 l sacks in 200 dm3 drums to the tilting equipment of the incinerator inlet box.     Incinerator

At the incinerator, existing and produced solid and liquid wastes from NPP of Jaslovské Bohunice site are burnt. The capacity of the plant represents 30 kg/h solid wastes if liquid wastes are burnt, or 50 kg/h solid wastes. Solid wastes are dosed to the feeding box through a system of boxes, the former representing a safety pass-through - loop.

The incinerator furnace has been designed as a shaft kiln fed from the top, there are no internal built-in parts in the furnace. Burning runs in two zones. In the bottom zone, a steam-air mixture is added, securing that the temperature of the burning materials will reach 900 °C thus eliminating the production of clinker and caking at the furnace walls. In the upper zone, the main volume of air is led directly above the burning materials (operation with excess oxygen) and the air volume is set so as to achieve burning temperatures of 800
¸ 1050 °C.

Flue gases from the furnace are post-burnt in a post-burning chamber at a temperature of 850
¸ 1100 °C. To the bottom part of the post-burning chamber water is sprayed thus reducing the temperature to 850 °C; reduction agent NOx-Out is added to this water in quantities as necessary to reduce the proportions of NOx in stake gases.

Water spraying and addition of compressed air to the mixing chamber reduce the temperature of flue gases to as low as 340 °C. Through the rapid cooling down, the temperature range of 600
¸ 350 °C is rapidly bridged thus substantially limiting the generation of dioxins. Subsequently, flue gases are washed in washers and cleaned at HEPA-filters that catch radioactive particles with a 99.9 % efficiency.

Ashes produced at the incinerator are reduced in size by a grinder, filled into 200 dm3 drums and will be transported to the cementation line similarly as the water used in flue gas washers. Currently, alternative processing of the ashes by compaction is being developed.     Storage and transport equipment.

The equipment serves the handling between the individual storage spaces and facilities of :

  • concrete containers,
  • 200 dm3 drums,
  • euro palettes.     Super compactor unit

At the super compactor unit, wastes packed after sorting or transported directly in 200 dm3 drums get compacted. By the high-pressure compactor, drums are subject to 20,000 kN. At every loading step, the pellet is ejected on withdrawal slides and placed on storage area; subsequently, it will be placed into concrete containers. At the cementation equipment, empty spaces of the container are filled with cement mixture.

Predchádzajúca kapitolaPredchádzajúca stranaOBSAHNasledujúca stranaNasledujúca kapitola