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 Appendix 3

PHYSICAL INFLUENCES

1. From sites of nuclear activity

1.1. Potential radioactive pollution from accidents

Accidents are possible during operations at nuclear installations, which may result in the emission of radioactive nuclides into the environment as gases or aerosols. The probability of a nuclear accident at any given nuclear site is generally calculated to be more than 106 years, i.e. less than one accident every million years. If the magnitude of an accident exceeds the maximum projected for the site, as it was at the Chernobyl Nuclear Power Plant (NPP) in 1986, significant amounts of radionuclides are emitted to the environment. For accidents of such magnitude, transboundary transport of pollutants is characteristic. The design of nuclear installations should provide that accident emergency systems localise the consequences of an accident in the territory of the installation.

The major dangers are from 131I aerosols, inert radioactive gases, other radionuclides. Iodine isotopes and inert gases create a short-term hazard, but other radionuclides may alter the global [gamma] background level and [alpha, beta] pollution.
The largest threats to Latvia from nuclear installations are Ignalina NPP and St. Petersburg NPP. Of course, major accidents at other NPPs in Russia, Sweden, etc. may also have hazardous consequences in Latvia.

1.2. Regular radioactive pollution

The operation of nuclear installations typically results in the regular emission of small amounts of radionuclides into the environment from gas and water treatment facilities. These amounts are practically too small to have any effect on the environment, with the exception of radioactive inert gases, that slowly alter the conductivity of air as they ionise. It is anticipated that will cause some climatic changes in the distant future. The collection of these inert gases was never addressed practically in NPPs of the former USSR, and in many Western countries this problem has not yet been completely resolved.

The operation of NPPs, and of any thermal power plant, results in the discharge of heat pollution into the closest watercourses. However, in Latvia this is not an issue.

1.3. The potential for pollution as a result of transport accidents

The operation of nuclear installations involves the transportation of radioactive materials and wastes. As in any transport operation, there is the probability that an accident may occur. Therefore, the planning of such operations must take into account the potential radioactive pollution of localised areas. Even if the containers used to transport new and used nuclear fuel have been designed to guarantee adequate safety, then nonetheless, in the case of an accident during the transportation of nuclear waste of medium-activity, particularly in liquid form, the environment is polluted.

In Latvia, such transportation operations are connected with the operation of Salaspils Scientific Nuclear Reactor. Up till now (since 1962) such accidents have not occurred.

1.4. Used nuclear fuel

This is a problem of national importance requiring an international solution. When the Salaspils nuclear reactor was constructed, no consideration was given to the containment of used nuclear fuel within the territory of Latvia.

1.5. Decommissioning the nuclear reactor

A special Cabinet decision has been enacted to address this problem of national importance, and to simultaneously address the following tasks: establishment of a fund to accrue the required financing (approximately 20 million Lats), retention of staff necessary for the operation, maximising the use of available international assistance.

2. From the use of radioactive substances

2.1. Potential radioactive pollution from accidents

Radioactive substances in available form i.e. liquid, powder or gas, are only used by several medical, scientific and educational institutions in Latvia. A fire in such a radiochemical laboratory may result in the emission of these substances into the environment. Such accidents endanger neighbouring areas.

Radioactive substances are mainly used from sealed radiation source, i.e. in a metal container, the construction of which ensures the containment of radionuclides even in case of an accident.

2.2. Regular pollution

The use of radioactive substances in available form typically results in the regular emission of small amounts into the environment from gas and water treatment facilities. There is a slight chance that several institutions that discharge radiation may be located in the same vicinity, each discharging only the permitted small and seemingly insignificant amount of radionuclides into the environment. However, once these amounts reach the communal sewage collector, the total may exceed permissible levels. In order to eliminate such a possibility, emission permits set allowances for a whole year as well as for specific operations. The location of the institution and possible summing of emissions is also taken into account.

2.3. The potential for pollution as a result of transport accidents

The use of radionuclides involves the use of transport, just as does the operation of a nuclear reactor. Different modes of transport offer different levels of safety, e.g. aeroplanes are widely used to transport new medicines, because even though the possibility of an accident is relatively high, the radioactivity of such substances is relatively insignificant.

A more important problem is the transportation of nuclear wastes from their site of use to the site of their final disposal. In case of an accident, local watercourses may be polluted this is turn may pollute the surrounding territories.

3. Non-ionising radiation

3.1. Light pollution

3.1.1. The emission of infra-red radiation in high temperature processes is a work safety problem.

3.1.2. The emission of infrared radiation in low temperature processes (or heat pollution) may be characterised as a global problem that influences the environment indirectly. It is directly associated with the production of electric power - as power losses. Thus, the problem should be discussed separately in connection with the production, transportation and consumption of electric power.

3.1.3. Ultra-violet radiation in high temperature processes is a work safety problem.

3.1.4. Ultra-violet radiation through an ozone layer of uneven density is a global problem that can only be directly influenced by using ozone-friendly substances. This problem should be discussed within the context of protection of the ozone layer.

3.2. Noise

3.2.1. Noise pollution is a problem of work safety in all industrial processes, as well as a problem for human habitation in industrial regions; in certain situations (repair works, construction) it creates discomfort for humans. Noise pollution is a local problem that should be individually solved for each case, often in connection with technology improvements.

3.2.2. Noise pollution from transport movements is a problem in the vicinity of highways, railroads, airports. The problem is widespread, but solutions require a certain level of financial support. In the field of aviation, it can partially be solved by applying international requirements for air transport.

3.2.3. Noise pollution in domestic areas is an insignificant problem, unless it is connected with industrial or transportation noise. It may be solved by increasing the level of understanding of the general public and of individuals.

3.3. Vibration

3.3.1. Vibration in technological processes is a problem of work safety.

3.3.2. Vibration caused by the movement of transport vehicles may be a problem in areas containing buildings of historic and cultural importance, especially in ‘old towns’.

3.4. Electromagnetic fields

3.4.1. Electromagnetic fields created by technological equipment generating constant electric radiation is a localised problem that is usually connected with work safety.

3.4.2. Electromagnetic fields from transmitters, radar - alternating fields and impulse-type radiation. Since this problem is yet not completely understood, but there are indications that there are negative impacts, the following approach should be adopted: if its application cannot be proven to be harmless, its potential impact should be reasonably reduced. Possible measures for solution include transition to the use of ultra-high frequencies, and raising the elevation of transmitters higher above the ground.

3.5. Electrostatic fields

3.5.1. The hazardous impact of electrostatic fields in the vicinity of power transmission lines is yet not completely understood. If possible, maximum safety should be applied.

3.5.2. An electrostatic field (surface charge) formed during an accident is a safety problem for humans and animals. The primary response should be to locate the accident site as soon as possible and nullify the source of electrical discharge.

3.5.3. Electrostatic fields in production industries is a work safety problem that also increases the risk of accidents (fire, explosion). For certain types of production, static neutralisers should be used - passive or active type.

3.5.4. Electrostatic fields in households is a domestic problem that increases with increase in the use of synthetic materials.

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Last updated: November 8, 1996. The information prepared by Valts Vilnitis: fuxis@varam.gov.lv