A NEW RADIOCHEMICAL BUILDING FOR THE INSTITUTE OF RADIOCHEMISTRY
- CONSTRUCTIONAL AND RADIATION PROTECTION ASPECTS -

ABSTRACT

A new building devoted to radiochemical work was commissioned in 1998. It is home to 24 radiochemical laboratories and additional 10 rooms for technical service rooms. In accordance to the German Radiation Protection Ordinance (§3) we are licensed to handle 135 different radionuclides, including transuranium elements. The alpha-laboratories are equipped with glove boxes allowing experiments with gram amounts of the actinide elements under ambient or inert gas atmosphere.

PURPOSE

This new radiochemical building is designed for studying the behavior of radionuclides such as uranium, thorium, neptunium, americium, curium, radium, technetium, carbon-14 and tritium, which are important for the environment and for the life sciences.

CONSTRUCTION

The laboratory building has a size of 20 x 35 m, with two stories constructed from prefabricated standard room containers in a frame construction. The dimension of such a container is 3.3 x 6.6 x 8.3 m (height x width x length). Fig. 1 shows a photograph of this frame construction during the building phase. It has 24 radiochemical laboratories and 10 service rooms: rooms for short-term storage of solid and liquid radioactive waste and waste water, a room for safely storing radioactive samples in special safes, a control room with devices for measuring and signalization of safety and radiation protection relevant data. A separate top floor houses all equipment for air conditioning, ventilation and filtering. Laboratories and service rooms were installed in the first and second floor, in the third floor all technique is located for air treatment. The ventilation system guarantees an increasing negative pressure gradient from the hall-ways to the laboratories and from the laboratories to the glove boxes and hoods.

EQUIPMENT

The laboratories (Fig. 2) are equipped with 22 alpha-boxes, laminar-boxes, hoods, dish washers for cleaning glass-ware, refrigerators, and drying cupboards. Modern analytic methods are established in the laboratories. These are nuclear magnetic resonance spectroscopy, different methods of laser spectroscopy, UV-vis/FTIR-spectroscopy, photon correlation spectroscopy, field flow fractionation, equipment for electrochemical measurements, and ultra centrifugation. Modern equipment for alpha-, beta- and gamma-spectrometry is also available. All laboratories are connected to a central gas supply station located outside the building. Up to four different gases can be used in each laboratory at the same time.

Glove box systems (Fig. 3) are installed for handling gram amounts of various actinide elements under air or inert gas conditions. Several boxes are foreseen for experiments under special gas atmosphere (humidity, CO₂ content).

MONITORING

All rooms are located in one controlled area. Radioactivity and the dose rate of the air are constantly monitored. The exhaust air is automatically surveyed for tritium, carbon-14, radioactive iodine, alpha-, beta- and gamma -activity in aerosols. All safety related data are monitored by an automated survey system. The entrance system to the building is controlled by an automated dosimetry system. This ensures a permanent overview and radiation exposure record for the personnel. According to the licence given by the Saxon Ministry of Environment in March 1998, we are licensed to handle 135 nuclides with a maximum of activity for each nuclide of 1011 Bq. Concerning the kind and number of radionuclides, the permission for handling radioactivity varies for each laboratory.

The radiochemical laboratory is open for all partners to work on joint research projects.