NL1038859C2 - DEVICE AND METHOD FOR THE PURPOSE OF PROCESSING NATURALLY RADIOACTIVE MATERIAL TO CONCRETE FOR USEFUL USE ELSEWHERE. - Google Patents

Description

Device and method with the aim of naturally processing radioactive material into concrete for useful use elsewhere.

Description 5 This process describes the processing of natural radioactive material whose activity is greater than or equal to 10 Bq / g, such as, but not limited to, slag wool, NORM and LSA scale.

Snail wool 10 Snail wool is an insulation wool that was produced and used in the 1950s and 1960s. This insulation wool was produced from slag released from the tin refining, hence the name "slag wool". The tin ore used as a raw material contained an increased concentration of natural radioactive substances, uranium and thorium. During the refining process, these radioactive substances have ended up in the slag, so that the slag is radioactive. The slag wool produced from these slags is therefore also radioactive. Snail wool with an activity> 10 Bq / g is subject to a licensing obligation under the Nuclear Energy Act and the slag wool cannot be transported to a conventional landfill like normal insulation wool.

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NORM

NORM ("Natural Occuring Radioactive Matter1) and LSA-scale (Low Specific Activity) are materials that are released during the production of natural gas. LSA scale is released as caking on the inner wall of, for example, pipes and vessels and NORM in the form of unconsolidated sandy streams ("sludge") from collection points in process equipment, such as from separators and collection vessels. Provided that the activity is greater than or equal to 10 Bq / g, this material is subject to a license requirement in accordance with the Nuclear Energy Act and may not be transported to a conventional landfill.

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Other naturally radioactive materials

In addition to Snail Wool and NORM, there are other natural radioactive materials which, if the activity is greater than or equal to 10 Bq / g, are suitable for processing according to this process.

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Process.

In accordance with the Natural Sources of Ionizing Radiation Regulation (NABIS) (DGM / SAS / 2004080182), Article 8 (1) and (2), the radioactive material (slag wool, NORM or other suitable natural radioactive materials; hereinafter referred to as' Material ') used as a sand substitute in the preparation of concrete. The radioactivity of the concrete thus prepared is so low (at least lower than 1 Bq / g, typically 0.3-0.5 Bq / g) that the concrete no longer falls under the Nuclear Energy Act and can be used freely as building material. This ensures that a potential waste material, namely the radioactive Material, is usefully reused.

The process is as follows:

The process takes place in a well-sealed space, the containment. This containment is kept under pressure by fans;

The following activities take place in this containment: 1. The radioactive Material is released from the device or component on which it is mounted. If the Material is in intermediate storage in a depot (such as a sea container), in cans or in big-bags etc. the depot, or cans, big-bags etc. will be emptied into the containment. If the material is not already finely divided (maximum particle size <3 mm), the Material will then be ground in a mill, the shredder, with or without the addition of water.

2. If there is a suspicion that metal particles are present in the ground product, those particles are removed from the ground product using a magnet. These metal particles are rinsed with water and, after release, disposed of as metal scrap.

3. If the material has not yet reached the desired dimensions (maximum length of the particles less than 3 mm), the Material will be subjected to a second milling device.

4. The ground or already finely divided material that has been stripped of any metal particles is weighed and mixed with wet, premixed concrete or with raw materials to form a product suitable for the production of 3 concrete. The maximum mass% Material in concrete must be such that the activity of the end product falls under the reporting obligation of the Radiation Protection Decree. For an activity of the untreated material of, for example, 10 Bq / g, the amount of Material in concrete must be more than 5 lower than 10 (mass -)%.

5. The concrete is then prepared in a mixer (for example a concrete mixer) with the addition of water. The wet concrete is poured into a pit or into molds; 6. After curing, the concrete is broken into small pieces ("granulate"). 10 This granulate can be certified under the Building Materials Decree

Alternatively, the wet concrete cast into molds after hardening is used as a molding for use elsewhere.

7. After completion of the work, the containment will be cleared away and delivered clean. After checking and release, the containment can also be used for 15 other activities.

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Claims (4)

Processing process of radioactive material (slag wool, NORM or other natural radioactive material, hereinafter referred to as 'Material') comprising (in order of processing) a process part in which the radioactive Material 5 may or may not be added with water from its container or from a component is placed in a shredder or grinder, the shredder; a process part in which the radioactive material, whether or not with the addition of water, is reduced by the shredder to particles with an individual length of up to 3 mm; optionally a process part in which the reduced material is taken in interim storage; a process part in which the comminuted Material is brought directly from the shredder or from the optional intermediate storage together with wet concrete or the raw materials for preparation of concrete into a mixing device with or without the addition of water, characterized in that the comminuted Material as a partial sand substitute or as an additive in the preparation of concrete. 2. The concrete mixture according to claim 1. is poured and hardened, and subsequently crushed with the characteristic that the crushed concrete is certified under the Building Materials Decree ("granulate") or is otherwise used as a molding. 3. The granulate or molding according to claim 2 can be freely traded and used, characterized in that the radioactive material from claim 1 is thus used for useful reuse. 4. The concrete mixture according to claim 1. is poured, cured and used elsewhere, characterized in that the radioactive material from claim 1 is thus used for useful reuse. 1038859