Antinuclear

Australian news, and some related international items

Dr Helen Caldicott explains the (virtually eternal) problem of toxic nuclear waste – Submission to Senate Committee

how much water would theoretically be required to dilute all the high level waste expected to be on hand in the USA by the end of the 20th century, to existing drinking water standards?

The answer: If you add up all the fresh water in the world, including not only all lakes and rivers and glaciers and ground water, but also all the soil moisture (which far exceeds the sum total of all the other sources), and then double that grand total, then you have about the right amount of water to do the dilution.

The USGS points out that this calculation is only to emphasize why it is so important to keep this material out of the environment to an unprecedented degree.

Dr Helen Caldicott – re National Radioactive Waste Management Amendment (Site Specification, Community Fund and Other Measures) Bill 2020 [Provisions]. Submission No. 71. have deep concerns about the federal governments proposed changes to the National Radioactive Waste
Management Act.

The government has not made a clear case about the need for the planned national facility at Kimba and the
process has been restricted and inadequate.
As a physician well versed in the dangers of radioactive waste and its longevity, its cardinogenicity and
mutagenicity I attach the following summary of the elements in radioactive waste, which is written for Canada
but applies equally to all radioactive waste. And by the way France which has produced our radioactive waste
from Lucas Heights calls it high level, not low level radioactive waste!
The high level waste from nuclear reactors remains extremely toxic for many millions of years — essentially forever.
There are hundreds of man-made (or human-made if you like) radioactive materials within irradiated nuclear fuel. Many of these disappear within the first few years, but even after ten years of “cooling” and rapid decay there are still hundreds of such radionuclides left. Here is a list of 211 of them taken from a publication by AECL (Atomic Energy of Canada Ltd): http://www.ccnr.org/hlw_chart html
This list is by no means complete.
You will notice that the radwaste materials in irradiated nuclear fuel are classified into 4 categories (by AECL). The main categories are FissionProducts, Activation Products (of which there are two types labelled FIAP  and ZAP), and Actinides (together with their decay products)
“Fission products” (FP) are the broken pieces of atoms which have been
fissioned in order to produce energy and/or neutrons in the reactor, along
with their immediate decay products. They are generally about 1/3 or 2/3
the “size” (mass) of the original fissile atoms of uranium or plutonium from
which they were produced by “fission”. (For example, uranium-235 gives rise
to strontium-90 and cesium-137; the first is roughly 1/3 and the second roughly
2/3 of the mass of the uranium atom (235). Most actinides are relatively shortlived,
but some are extraordinarily long-lived (e.g. technetium-99 has a half-life
of 210,000 years and iodine 129 has a half-life of 17 million years.)
“Activation Products” (AP) are radioactive atoms created when a non-radioactive
atom absorbs a neutron and becomes unstable — thus non-radioactive cobalt-59
becomes intensely radioactive cobalt-60, and non-radioactive iron-54 becomes
radioactive iron-55. These activation products are the main reason why metal
components from the core area of a nuclear reactor cannot be recycled but must
be treated as radioactive waste. But the fuel assemblies themselves also contain
troublesome activation products from chemical impurities in the fuel (FIAP) and in
the zirconium fuel cladding (ZAP).
“Actinides” are radioactive materials which have an atomic number higher than
that of Actinium. Most actinides are extremely long-lived. This includes naturally
occurring radioactive materials such as uranium and thorium as well as man-made
radioactive materials such as neptunium, plutonium, americium, curium, etc., all
created when a naturally-occurring actinide such as uranium-238 or thorium-232
absorbs one or several neutrons, followed by one or more “beta decays” in order
to become atoms of higher atomic number than uranium’s 92 (the highest naturally occurring
atomic number). To see how plutonium is created inside a nuclear reactor,
for example, see the animated graphic: http://ccnr.org/breeding ana.html . Those
man-made actinides that are beyond uranium in the periodic table (such as plutonium)
are often called Transuranic elements (TRU).
This graphic from a 1978 publication of the US Geological Survey shows the
radiotoxicity of selected radionuclides in irradiated nuclear fuel over a period
from 1000 years to 10 million years after emplacement, compared with the
radiotoxicity of the associated mill tailings (i.e. the leftovers from mining the
uranium needed to produce the same amount of energy as the nuclear fuel)
over the same time period:
The text of the USGS publication begins by asking the question, how much
water would theoretically be required to dilute all the high level waste expected
to be on hand in the USA by the end of the 20th century, to existing drinking
water standards? (In other words, to achieve the maximum permissible degree
of radioactive pollution of drinking water….)
The answer: If you add up all the fresh water in the world, including not only all lakes and rivers and glaciers and ground water, but also all the soil moisture (which far exceeds the sum total of all the other sources), and then double that grand total, then you have about the right amount of water to do the dilution.
The USGS points out that this calculation is only to emphasize why it is so important to keep this material out of the environment to an unprecedented degree. In my own words, 99% containment is nowhere near good enough. Even 99.99% containment would represent an unacceptable situation.
  [ Using this graph at   http://ccnr.org/usgs.html    Dr Caldicott explains the toxicity of the various
nuclear isotopes, and their decay times] …….
For the first 500 years, the radiotoxicity is dominated by the Fission Products (indicated by the red line in the graph). In particular the inventory of cesium-137 and strontium-90 (each with a 30-year half-life) plays a very important role for the first few centuries. But after that time, the radiotoxicity is dominated by the actinides (represented by the pink line) and their decay products..

From 1000 to 100,000 years, the radiotoxicity is mainly due to the transuranic
elements — plutonium, americium, curium, etc. But after 100,000 years, the
toxicity actually increases rather than continuing to decrease. This is because
of the ingrowth of decay products — many of which are more long-lived and/or
more radiotoxic than their parent actinides. For example, plutonium-239
has a half-life of 24,000 years, but its immediate decay product is uranium-235,
which has a half-life of 700 million years — so in fact plutonium-239 remains
dangerous not just for tens of thousands of years, but for hundreds of millions
of years. (And by the way, while plutonium-239 is excellent material for a nuclear
weapons explosive, so is uranium-235, its decay product!)

And one thing that many people forget is that MOST of the irradiated fuel is still U-238
(naturally-occurring depleted uranium) with a half-life of 4.5 BILLION years. While it
is true that U-238 is not highly radiotoxic, its decay products are EXTREMELY radiotoxic,
especially the radium, radon and polonium isotopes. So after about a million
years, the fuel elements are more radiotoxic than a 95 to 98% grade natural uranium ore
deposit, which has never been seen on the face of the earth. At Cigar Lake in Northern
Saskatchewan, they have uranium ore that reaches an “extremely high” grade of 7-8%,
and they have to use robots to mine it because the radiation levels are too much for
humans. Well after a million years, the irradiated nuclear fuel will be 12 to 14 times more

radiotoxic than the Cigar Lake ore, based on the uranium decay products alone!
You will notice in the color chart above that the buildup of RADIUM in the irradiated fuel
(indicated by the line composed of yellow circles) is what adds so much to the toxicity after
100,000 to 1,000,000 years. In this context it is important to realize that, as toxic as radium
is, the polonium isotopes which accompany it are far more toxic still. According to the Los
Alamos web site, polonium-210 is 250 BILLION times more toxic than cyanide (on a milligram
by milligram basis).
The penetrating radiation from
irradiated nuclear fuel diminishes
greatly over the first 500-1000 years.
It is primarily gamma
radiation from the relatively short-lived fission products
and activation products.
Thus the irradiated nuclear fuel becomes more approachable
after a few centuries and can even be “handled safely” for short periods of time after
several few centuries have passed — a fact that nuclear
proponents often use to suggest that the wastes aren’t very
radioactive (and by implication, not very dangerous) after
500 years.
But this is a grossly misleading interpretation, because the
radiotoxicity of the irradiated fuel is still extraordinarily high
as an ingestion or inhalation risk. This stuff is extremely poisonous
even though the penetrating radiation has dropped off significantly.
The long-term radiotoxicity is mainly due to the fact that most actinides have
extremely long half-lives and are — for the most part — emitters of a
non-penetrating but deadly form of atomic radiation called alpha radiation.
While alpha radiation is generally harmless outside the body, it is
extremely dangerous when it comes in close contact with living cells.
Throughout the 20th century, the most dangerous naturally-occurring
radioactive materials by far
were all alpha emitters — this includes radium, radon, and polonium
isotopes, as well as uranium and thorium.
It is a well established scientific fact that non-penetrating alpha radiation is much more biologically damaging than an equivalent amount of energy

from gamma radiation — it is about 20 times more damaging per unit
of radiation energy deposited in tissue, and about 200 times more
damaging per radioactive disintegration. Thus an irradiated nuclear fuel
bundle remains one of the most dangerous objects on Earth forever.

Besides, the penetrating radiation isn’t gone forever — it returns with a
vengeance after a few more millennia. By the time a million years have gone by, the
high level waste has once again become unapproachable — as the daughter
products of the actinides include many strong gamma emitters. https://www.aph.gov.au/Parliamentary_Business/Committees/Senate/Economics/RadioactiveWaste/Submissions?fbclid=IwAR0v

May 2, 2020 - Posted by | AUSTRALIA - NATIONAL, Federal nuclear waste dump

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