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Tuesday, 5 June 1984
Page: 2562

Senator TOWNLEY(10.40) —I was also outside Parliament House for some time when this demonstration took place today. I think not only the Senate but also Australia should congratulate Senator Jessop for bringing to the attention of the media just what a fraud the situation was out there. I was absent from the chamber just a moment ago, but I think Senator Jessop has most probably detailed the readings that we took together earlier in the day of the radiation levels that were measurable with a scintillometer. The levels that we got on the lawn opposite Parliament House were 38; on the steps where there is a lot of concrete they were 47. All of the measurements are in counts per second. I think Senator Jessop mentioned the monument opposite Parliament House which is made of granite. All granite contains a considerable amount of radioactivity. The measurement for that monument was 52.

I took this scintillation counter and physically put as must of it as I could in the container that had brought that material from South Australia. I got a reading of only 52. Had this demonstration taken place in Melbourne the reading from the container most probably would have still been 52, but the surrounding radioactivity would not have been as high. Honourable senators will be pleased to know that the readings in this chamber in which there is a lot of wood seem to average about 30, 34 or 35 which is much less than that for any office in this building which is constructed of concrete.

I was quite surprised that the reading of the material that was brought to Canberra was only 54. But then, I thought, really I was not because some of the people who organise these protests are clever. They are not going to place themselves at risk. They knew that the level of the material that was in the container was less than they would get from sitting on granite. They wrapped it up, though, to make it look as though it was dangerous. I object to that kind of action.

Senator Jessop —They even had special costumes on, too.

Senator TOWNLEY —That is all part of the act. It is all a theatre.

Senator Walsh —They had what on?

Senator TOWNLEY —They had masks, gloves and costumes. It is all a part of a theatre and it is about time this country understood what is going on. It is a dangerous theatre that is easily understood when one thinks about why this is happening.

Today we received in the mail through Parliament House a document titled ' Chemicals Can Be Hazardous and Take Care'. Yet we have to say in the Senate tonight that chemicals that were labelled dangerous in front of this House today were not dangerous. I object to having to do that. I believe material should be properly labelled. As a chemist, I have been in the habit of informing people when things are dangerous and when they are not. The material in that lead container outside was not in any way dangerous. In fact, one of the gentlemen from the Health Department in Canberra who came to measure whether it was dangerous or not said that he was at much more risk from the fumes driving here than he was from the material that those people put on the ground outside.

I am a little bit disappointed with some of the television news people who tonight left the public with the impression that that material was dangerous. They always go for the sensational side and they do not always show the truth.

Senator Peter Baume —What would an engineer's view be?

Senator TOWNLEY —As an engineer, I can assure the honourable senator that I understand what this machine does.

Senator Walsh —I do not.

Senator TOWNLEY —Let me briefly explain it to the Minister. It really counts the number of gamma radiations which come through a little crystal at its front. The reading is amplified. If one wanted to, one could make a noise with this machine . However, I will not do so. We have to remember that in every tonne of soil, which is about a cubic metre, on average there is about 3 grams of uranium. There are certainly 5,000 million tonnes of uranium dissolved in the oceans of this world. Any country, if it can afford to do so, can extract uranium from the sea. It cost about, I think, $750 to get a kilogram of uranium from the sea. However, I am not quite sure what the exact figure is for a pound or a kilogram.

Senator Walsh —If you want to make a bomb, it does not matter much anyhow.

Senator TOWNLEY —That is right. If someone wants to make a bomb he does not do it by getting the material from a power station. He does it by specifically designing a breeding station that will produce the plutonium that he needs.

I think it is time that the people of Australia were informed that nuclear stations are producing a permanent source of power. It is a reliable source of power and, after hydro-electric power, in most countries it is the preferred method. If one cannot get power from hydro the next step is to go to nuclear power, and then one goes down the line to coal, oil and other materials. The nuclear power stations that are operating are reliable. Over half the power that is produced in France-57 per cent I believe-is produced from nuclear reactors; 42 per cent in Sweden is produced from nuclear reactors; and about the same amount is produced in Finland. But we have to remember that there are not as many reactors in those countries as there are in the United States of America. In the United States there are 85 operating reactors. Those that are on line are reliable and will continue to be reliable for many years to come. There is a temporary lull because of the monetary cost of establishing nuclear power stations but this lull is only temporary. It is anticipated that in the early 1990s more stations will be designed and brought on line. As more stations are built they will be cheaper. One of the costs incurred in the building of some stations recently in the United States was what is called a learning curve. Mistakes that had been found had to be retroactively fixed. Such an exercise always costs a lot of money.

I believe that when people attempt to do what they did in this city today and try to scare not only the people of Canberra but the whole community in an attempt to stop the development of Roxby Downs and to influence the Australian Labor Party Conference that is going to be held later this year, it is up to those people who have a little bit of knowledge in this matter to make that knowledge available to the people of this country. We have to remember that radioactivity is naturally occurring.

I have in my hand a document titled 'The Naturally Occurring x-Ray Activity of Foods' which was printed, I think, early in 1958 but which was certainly received by 31 July 1958. Mostly people think that foods are perfectly pure, but they are not. Most foods have some form of radiation. The abstract in the article states:

Most of the activity is due to members of the thorium and radium series. There is a factor of 20,000 between the most active and least active foods. The most active food so far measured is the brazil nut; breakfast cereals have the next highest x-activity. In general, values in milk products, fruits and vegetables are low. The x-activity seems to increase with the phosphorus content of foods.

It goes on to say:

In general, an adequate diet will not contain less than 2 x 10-12c of alpha radiation per day.

I do not wish to go on for too long because I am sure that at some other stage we will be talking about the danger of concrete, the danger from timber inside buildings, particularly of freshly-cut pine inside a building which does not have good ventilation, or of going near a granite mountain. The inhabitants of Flinders Island would presumably all have to move away because it is almost totally granite, as is Wilsons Promontory.

Senator Peter Baume —What about Jabiru? It would be very high.

Senator TOWNLEY —I have not taken my little machine up to Jabiru so I cannot tell you what the background reading is there. But if I took it to Flinders Island, with the radiation from space at its normal level, the machine would read just about the same as it does at the statue across from Parliament House and the same as the sand or whatever the sludge was that was brought here today. With the permission of the Minister and the Senate I wish to incorporate in Hansard a small article that points out how radiation and radioactivity are measured.

The PRESIDENT —You say it is a short article. Just how long is it?

Senator TOWNLEY —It is two pages, pages 65 and 66 of this document.

Leave granted.

The document read as follows-


Radioactivity and Radiation

Some of the elements that occur in nature are unstable in that their constituent atoms change spontanteously into atoms of a different element. Because the change is accompanied by a release of energy, which radiates outwards from a particle of an unstable element, the element is said to be ' radioactive' and the process of conversion to another element is called ' radioactive decay'. Uranium and radium are examples of naturally occurring radioactive elements.

In addition to the radioactive elements which are found in nature, many others can be created artificially. One large class of these is the fission products that are formed when certain forms of uranium or plutonium undergo fission in a nuclear reactor or in a nuclear explosion. There are many of these: iodine-131 and strontium-90 are two well-known examples. The numerical suffixes indicate the mass of an atom of the element in question. The distinction is necessary because an element may exist in several different forms, known as isotopes, which have identical chemical properties but differing atomic masses. Strontium, for instance, in the natural state is a mixture of four stable isotopes, but ten radioactive isotopes of strontium are found in fission products. The different radioactive isotopes of one element have different radioactive properties. There are other means of creating radioactive isotopes of stable elements. If the electrically neutral subatomic particle, the neutron, is captured by an atom of a stable element, the mass of that atom is increased by one unit and it becomes unstable. This process is called 'activation'. Large numbers of neutrons are generated in the reactions of nuclear fission, and if these encounter suitable targets, activation products are formed. Activation products will be formed in soils near the site of a nuclear explosion, if it is fired on the ground or at a moderate altitude.

Radioactive elements mostly decay by the emission of either alpha particles, which are electrically charged atoms or helium, or beta particles which are light, electrically charged, subatomic particles. As well as energetic particles , radioactive atoms may also radiate energy as gamma radiation which is non- particulate and is an electromagnetic radiation similar to light and radiowaves. There are important differences between the three types of radiation. The particulate forms are easily stopped; alpha particles are the more easily stopped and cannot penetrate the skin, and beta particles, though they may penetrate the skin cannot travel much further in the tissues unless they are of very high energy. It is a characteristic of particulate radiation that it has a finite range in any absorbing material; after a certain thickness it is sharply cut off and anything beyond is completely screened. Electromagnetic radiations are progressively attenuated as they pass through matter, but there is no sharp cut-off point. The different characteristics of alpha, beta and gamma radioactivity determine the way in which they may present a risk. Alpha radiation can present a hazard only if an alpha radioactive material is taken into the body by inhalation, ingestion or through injured skin, and is then retained. Beta radiation may present an external hazard but the injury will be confined to the skin and superficial tissues; it presents a greater hazard if its source is taken into the body and retained. Gamma radiation, on the other hand, can irradiate any part of the body from the outside and may present a serious external hazard as well as an internal one.

The general term 'radiation' includes, in addition to the radiations associated with radioactivity and nuclear fission, the various forms of electromagnetic radiation: radiowaves, microwaves, infra-red, visible, and ultra-violet light, and X-rays. We are concerned here only with those radiations which can produce ' ionisation', directly and indirectly, in the materials that they traverse. Ionising radiations can create electrical disturbances, in the atoms of the material traversed, which can break the chemical bonds that link the atoms of a compound into its molecule. It is this property that makes ionising radiation harmful to biological material. The injury may be expressed at an early stage as a cell death, or it may be manifested much later as a delayed effect of exposure to radiation. The ionising radiations are, for practical purposes, alpha radiation, beta radiation, gamma radiation, neutrons and X-radiation.

Quantities of Radioactivity and Radiation

The unit of radioactivity was originally based on the properties of radium. That unit was the 'curie' and was taken to be the activity of one gram of radium , though it was subsequently defined formally as 3.7 * 1010 s1. For use in radiation protection, the curie was a rather large unit, and sub-multiples in powers of 10 came into common use. e.g. millicurie (1/1 000), microcurie (1/1 000 000) and picocurie (1/1 000 000 of a microcurie). The curie units were in use at the time of the nuclear tests in Australia, and are still frequently encountered, but have now been replaced by a new unit, the becquerel, to comply with the requirements of the International System of Units. The becquerel is defined as 1 s1, i.e. one radioactive disintegration per second, and is very much smaller than the curie. It is usually encountered as a multiple, in powers of 10, e.g. kilobecquerel (kBq). Some equivalents are:

1 microcurie = 37 kilobecquerels (kBq)

1 millicurie (mCi) = 37 megabecquerels (MBq)

1 kilobecquerel (kBq) = 27 nanocuries (nCi)

1 megabecquerel (MBq) = 27 microcuries

In this report only the becquerel system of units is used. Some perspective to the numbers can be obtained by noting that an average soil contains about 1 Bq or 30 pCi of natural radioactivity in each gram, and that the human body contains, on average, 5 kBq or 120 nCi of the natural radioactive isotope, potassium-40.

At the time time of nuclear tests in Australia, exposure to radiation was measured in roentgens (r or R). The roentgen was a unit of exposure, defined in terms of the ionisation produced in air under standard conditions. It was not necessarily an exact measure of the energy deposited in an irradiated tissue, which depends on the energy of the radiation and the density of the tissue. For this reason, at about the time of the completion of the nuclear test series, a unit of absorbed dose, the rad, was introduced in order to avoid ambiguity about what was meant by the term 'radiation dose'. The rad was defined as the deposition of 100 ergs per gram of irradiated tissue. Because one rad of certain kinds of radiation, principally those involving neutrons and alpha particles, often has more biological effect than does one rad of X-rays or gamma rays, a further unit was required to allow for the difference. The unit was then rem, and it was obtained from the rad with a multiplying factor, the 'Quality Factor' , which allowed for difference in biological effectiveness of different kinds of radiation.

Much current legislation is written in terms of the rem but, because it was not compatible with the International System of Units, it has now been replaced by another unit. The basic unit of absorbed dose is now the gray, defined as 1 joule per kilogram; it is 100 times larger than the rad. The unit corresponding to the rem, the unit of 'dose equivalent' is called the sievert and it is 100 time larger than the rem. The present report uses only the sievert or its sub- units, millisievert and microsievert. It may be helpful to remember that the numerical values of the roentgen, the rad and, for most radiations, the rem, will, for a given set of circumstances, be approximately equal. Further, one millirem is the equivalent of 10 microsieverts. Because the doses in question are mostly minute, the unit most used in this report is the microsievert.

Appendix 3 gives some perspective on the dimensions of the reported radiation doses.

Senator TOWNLEY —As a chemist, I object very strongly to people trying to use scare tactics. Things should be labelled the way they are. Those people today did a disservice by labelling any material and when they attempt similar things in the future, I intend to take as much action as I can to show them to be the frauds that they are.