Research facilities

The research facilities category includes particle accelerators, industrial research and development centres, universities, and national laboratories and institutes. Many of these facilities use a wide variety of radioactive materials.

General research laboratories use small quantities of various radiotracers in their research work, which includes medical and pharmaceutical research, veterinary research, environmental pathways research, basic research and agricultural research. The typical laboratory or research facility is a changing environment regardless of the type of institution in which it is situated. As programmes and research projects are completed, new ones are initiated and

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the working environment changes, potentially posing new challenges to the decommissioning team when the entire facility eventually requires demolition or refitting for a new research programme.

The range in size and complexity of some of these types of facility and of their subsequent decommissioning is considerable. In the USA, there is one organization that is performing a large scale decommissioning of an entire suite of facilities, including not only research facilities but also research reactors, a fuel fabrication facility, hot cell facilities and a particle accelerator facility.

Other facilities falling into this general category may consist simply of the typical research laboratories with fume hoods, sinks, gloveboxes, hot cells and the basic research laboratory furnishings.

3.5.1. Particle accelerators

Various types of particle accelerator can be found in research, medical and industrial settings. Some accelerator facilities are also used for the purpose of radioisotope production. Most of these machines are routinely upgraded or refurbished (an example of this is the CERN facility) over their operational lifetime. In some instances, entire units can be disassembled, transported to a new location, and reconfigured and operated there for some period for other purposes. At the same time, some portions of the particle accelerators may be disposed of while other parts are reused or cannibalized for use in a new machine at the same site.

Typical types of particle accelerator include linear accelerators, cyclotrons, synchrotrons and Van de Graaff generators, and there are also a number of other, sometimes unique devices of the particle accelerator type.

Although very little is to be found in the technical literature about the decom-missioning of these types of facility, there has been considerable decommis-sioning accomplished. Typically the decommisdecommis-sioning is done in a very straightforward manner using very simple techniques. Usually many of the components are reused at other facilities, with a minimal amount of waste arising from these decommissioning projects. A large quantity of waste is generated only in cases where the facility is extremely old and was not well operated [12, 13]. Even in these cases the activity content of the resulting waste is of very low concentration and is small in quantity.

Recently medical diagnostic processes which use cyclotron generated radioisotopes (e.g. SPECT (single photon emission computed tomography) and PET (positron emission tomography)) have become more commonplace.

Unless the particle accelerator facility generates particles with energies greater than a few megaelectronvolts, decommissioning is not a major concern.

Table 4 provides a summary of the status of particle accelerators that might require decommissioning. This information is based on the data presented in Annex IV. It is difficult to obtain information regarding all of the accelerators worldwide, since there are a very large number and there is no set of documents that provides a complete listing. For this study, only facilities that have indicated startup dates have been included. This appears to be about half of the total number of facilities [14].

3.5.2. Medical facilities

There are approximately 37 000 medical facilities that use radioactive material in various activities worldwide, with about 6700 of these using radioactive material in an unsealed form [11]. Most of the unsealed radioactive isotopes used in medicine are radionuclides with short half-lives that will rapidly decay to background levels. There are a few exceptions to this rule, mainly ¹⁴C and ³H, which have half-lives of 5280 and 12.3 years, respectively.

Teletherapy and brachytherapy treatment regimes use sealed sources of radioactive material for various treatment and therapeutic programmes. In the USA alone, there are on average about 10–12 million diagnostic and therapeutic clinical procedures performed annually using radioactive material, resulting in a large number of facilities that are very slightly contaminated.

Individually they produce only a small quantity of waste, but when the volumes of waste and the number of sites are considered collectively, the figures are rather impressive. In some cases, because of the leakage of sources, some facilities may become contaminated and require extensive decommissioning.

Areas used in hospitals for the preparation of medical radioisotopes and patient rooms may also require decommissioning whenever renovations are made to these areas. Some recent IAEA Technical Reports Series publications detail experience in the decommissioning of areas used for radium and caesium needle storage in older hospitals [15, 16].

TABLE 4. SUMMARY OF THE STATUS OF PARTICLE ACCELERATORS (AS OF AUGUST 2003)

Operating 406

Under construction 9

Shut down or being decommissioned 5

Decommissioned 1

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3.5.3. Laboratories

There are a large number (about 320 000 [11]) of research laboratories worldwide that use radioactive material. These range from small, one room facilities at smaller universities to large, multiroom laboratories at larger insti-tutions or major research facilities, such as those of pharmaceutical companies or private corporate research centres. These laboratories vary in complexity from those using only sealed sources to those using loose fissile material or larger quantities of other radioactive material.

Industrial laboratories tend to use radioisotopes with short half-lives for various testing programmes and activities to assist with product development or with the processing of material, for example in measuring the thickness of a material or the liquid level in a container.

Universities tend to use a wider and more diverse variety of radioisotopes in their work. A wide range of radioisotopes in various forms in a variety of applications can be found in academic research laboratories.

Hot cells are used for the examination of irradiated material or other samples that require some containment and isolation for their handling. Often these can be found in conjunction with a research reactor; in other instances they may be found in a ‘stand-alone’ configuration or possibly in conjunction with other research facilities.

Pharmaceutical laboratories tend to use short lived isotopes, but they may also use ¹⁴C and ³H. Some of these facilities are major complexes and may be contaminated with organic material that could make waste disposal more difficult.