Friday, June 29, 2012

Which is more radioactive, Potassium-40 or Thorium-232?

Recently one professor and one nuclear scientist claimed that potassium-40 is far LESS radioactive than Thorium-232 and they cited the EPA (environment protection agency of American) and the WHO UNSCEAR as proof of their statements!
One of my friends who stated that K-40 is about 62 times more radioactive than Thorium-232 was rubbished by the nuclear scientist!
Well, that depends on what we are talking about.
Quote ” It was written somewhere above that potassium-40 is 62 times more radioactive than thorium. That is, I am sorry to note, a complete and utter rubbish:”
Unquote.
1. I think what my friend was thinking about is radioactivity in terms of Bq i.e. activity rather than biological effect (Sv) when he said potassium-40 is 62 times more radioactive than Thorium-232.
Pure Potassium-40 = 254,000 Bq/gram
Pure Thorium-232 = 4,080 Bq/gram
Therefore potassium-40 has about 62X more Bq than Thorium-232
Even in terms of biological effect, 1 gram of pure potassium-40 will still have a greater biological effect when compared with 1 gram of pure Thorium-232.
****************
Pure Potassium-40 = 254,000 Bq/gram
Quote from nuclear scientist: 1 Becquerel per gram of K-40 in the soil (should actually be 1 Bq of K-40 per gram of soil) results in an increase in gamma-levels by ~0.042 microSieverts per hour (WHO UNSCEAR). Unquote
Therefore 254,000 Bq = 10,668 microSieverts/hour
(from 1 gram of pure potassium-40 i.e. not mixed with K-39 and K-41)
****************
Pure Thorium-232 = 4,080 Bq/gram
Quote from nuclear scientist: Each becquerel per gram of Th-232 (should actually be 1 Bq of K-40 per gram of soil) increases this level by ~0.604 microSv/hour.
Therefore 4,080 Bq = 2,464 microSieverts/hour
*************************
10,668 microSv/hr divided by 2,464 microSv/hr = 4.33
or the biological effect of radiation from pure Potassium-40 is actually 4.33 times more than that of pure Thorium-232.
2. If we are talking about 1 gram of naturally occurring Potassium which contains only 0.0118% of K-40, then it is perfectly correct to say that Thorium-232 is more radioactive biologically than Potassium as the naturally occurring potassium has only 32 Bq per gram as compared to K-40 which has 254,000 Bq per gram.
So 32 Bq of K = 1.344 microSieverts/hr while 4080 Bq of Thorium-232 = 2,464 microSieverts/hr which is far more biologically radioactive than Potassium.
3. If we compare radioactivity in terms of becquerel (number of atoms decaying per second), 1 Bq of course is equal to 1 Bq in terms of activity.
But in terms of PER Bq (radioactivity from only one nuclear decay) the biological effect, according to UNSCEAR, Potassium-40 and natural potassium is less radioactive biologically than Thorium-232 (but remember that 1 gm potassium-40 has 254,000 atomic decay per sec while 1 gm of Thorium-232 has only 4.080 atomic decay per second ).
SO, BEFORE YOU RUBBISH ANYONE FOR SAYING THAT POTASSIUM-4O IS MORE RADIOACTIVE THAN THORIUM-232 OR VICE VERSA, MAKE SURE YOU KNOW WHAT YOU ARE TALKING ABOUT.
It all depends on whether you are comparing activity (Bq) or biological effect (Sv), whether you are taking about pure potassium-40 or natural potassium which is composed of only 0.0118% highly radioactive K-40 and whether you are comparing Bq per gram of potassium-40 or Bq per gram of soil.
Moreover, we have to state that the Thorium-232 is not that of pure Thorium-232 as freshly isolated pure Thorium-232 do not produce any gamma rays and as such has practically no external biological effect (the 0.09 MeV of gamma rays in freshly isolated Thorium-232 actually comes from Radium-228).
The same arguments apply to the comparison of the cancer coefficients of potassium-40 and Thorium-232.
In fact the nuclear scientist had to apologise and agree that it all depends on what we are trying to compare with.

6 comments:

  1. From the New Straits Times Press, Ahmad Ibrahim, Fellow of Academy of Sciences, Malaysia Quote:

    "La Rochelle, the 'Lynas of France'

    Many would be surprised that La Rochelle has for decades been hosting a rare earths processing plant, similar to the one planned in Malaysia.

    The La Rochelle facility, which belongs to France's Rhodia Group, has for years been operating like Lynas. Forty years to be exact. And there has been no adverse health and safety report in the tourist town.

    The Rhodia company is an active player in the rare earths business. It is a leading processor of rare earths. In fact, it's the only fully integrated industrial player to have manufacturing operations and raw material supply both within and outside China.

    The plant in La Rochelle has been in operation for more than 50 years.

    In the early years, the plant processed rare earths ore concentrates from Australia and China just like Lynas would. For 40 years, the plant was operated in this manner, producing cerium for the world market.

    The radioactive thorium residues have been stored within the plant's 40ha site for the past 50 years. During storage, the residues are regularly monitored by the country's regulatory authority, the equivalent of our Atomic Energy Licensing Board (AELB).

    They believe the stored thorium salts will become a fuel of the future.

    What is clear is that the rare earths processing facility in La Rochelle has been operating for more than five decades without harming the population. Instead, La Rochelle has thrived over the years as an attractive tourist destination not only for the French but also for holiday-makers from other European countries and even as far away as the United States.

    Through the deployment of stringent health and safety standards, the chemical plant has been of no consequence to the local community.

    Instead, it has contributed to the local economy not only in terms of job opportunities but also tax revenues.

    After visiting La Rochelle, it beats me why there are still people who are so hung up on Lynas."Unquote

    Quote: AELB (Atomic Energy Licensing Board, Malaysia):

    Malaysia was the world's no. 1 producer of tin. Along with tin, there's always Thorium and Uranium and therefore this is not Malaysia's first facility, AELB is has experience to handle this, to overcome this and AELB is prepared.


    THERE ARE MORE THAN 10 FACILITIES THAT ARE VERY SIMILAR TO LYNAS.

    SOME OF THEM ARE PRODUCING HIGHER RESIDUES, HIGHER CONCENTRATION OF URANIUM AND THORIUM.

    AELB has been able to regulate and control these factories, so it is based on AELB experience and the experience of the industry abroad." Unquote


    QUESTION: WHY IS IT THAT THERE ARE NO DEMONSTRATIONS BY
    THE ANTI-LYNAS FOOT-SOLDIERS AGAINST THESE 10 CHEMICAL
    PLANTS ALREADY IN MALAYSIA THAT ARE PRODUCING "WASTES
    WITH HIGHER CONCENTRATIONS OF URANIUM AND THORIUM"?

    ANSWER: 100% PURE POLITICS FROM TOXIC RADIOACTIVE POLITICIANS !

    Dato' Dr Looi Hoong Wah
    FAMM, MB., ChB(Manchester), MRCS(England), MRCP(UK), MRCP(London)

    ReplyDelete
  2. .
    QUESTION BY ANTI-LYNAS: "CAN YOU BE SURE THAT THE LYNAS PLANT IS 100% SAFE ?
    .

    AND AS FAR AS THE 100% BUSINESS IS CONCERNED, THE ONLY THING IN LIFE WHICH WE CAN BE A 100% SURE OF IS THE CEMETERY AND THE LAVATORY. IF WE HAVE TO GO, WE HAVE TO GO 100%.

    The chance of dying one day is 100%. So do not worry yourself to death about it!

    • Dying from heart disease -- 1 in 6 (lifetime risk)
    • Dying in an auto accident -- 1 in 75 (lifetime risk)
    • Committing suicide -- 1 in 71 (lifetime risk)
    • Being Murdered -- 1 in 140 (lifetime)
    DYING FROM CANCER - 1 in 5 (lifetime risk)
    • Being struck by lightning -- 1 in 10,456 (lifetime)
    • Seriously injuring yourself while shaving -- 1 in 5,844 (annual risk)
    • Going to prison this year -- 1 in 139
    • Dying from falling out of your bed or chair -- 1 in 513,142
    • Being stuck and killed by a falling aircraft -- 1 in 25 million
    • Getting food poisoning -- 1 in 8 (annual risk)
    • Hiring a sleazy lawyer -- 1 in 8
    • Freezing to death (in non-tropical countries) -- 1 in 780,938 (annual risk)

    SO ANTI-LYNAS FOLKS, IF YOU DO NOT WANT TO DIE FROM CANCER OR SOMETHING NASTY, THE BEST THING TO DO IS NOT TO BE BORN!

    If one is already born, the best way to avoid dying from cancer is to die young from other illnesses like dengue, bird flu or malaria or from accidents!

    MAYBE, IF ONE IS ALREADY BORN, ONE OF THE MOST PLEASANT WAY TO DIE IS TO DIE UNDER GA (GENERAL ANAESTHESIA) WHEN HAVING A SURGICAL OPERATION.

    VERY PLEASANT, NO PAIN, NO KNOWLEDGE, JUST LIKE GOING TO A NORMAL SLEEP AND YOU DIE UNDER THE CLEAR KNOWLEDGE THAT YOUR WIFE AND FAMILY WILL BE WELL TAKEN CARE OF FINANCIALLY because they will be able to sue the surgeon and hospital for millions of dollars ! Dying in any other way which include heart disease, infection, renal failure, lung failure, cancer or even "old age" can be rather painful and uncomfortable !

    The risk of dying from a road traffic related accident in Malaysia is much higher than that which has been predicted for the death from radiation induced cancers.

    For instance in 2009, there were 6,745 deaths in a population of 27.9 million giving a rate of 24.17 deaths per 100,000.

    The main reason why the people of Kuantan is so frightened of the "Fukushimization" of the Lynas plant is pure and simple politics.

    The chairman of the coalition of one of the anti-lynas organisation said in one of the Blogs:

    Quote: "Thanks for the clarification. I agree with you, the will of the people must prevail, IRREGARDLESS OF WHETHER THE LAMP IS SAFE OR NOT1" Unquote.

    What the above statement means in simple non-Australian English is that THE WHOLE ISSUE IS 100% POLITICS AND THERE IS REALLY NOTHING WRONG WITH THE LYNAS PROJECT except that it is a fantastic political tool for certain politicians to gain POWER.

    ONCE THE GENERAL ELECTION IS OVER, LYNAS WILL BECOME A HIGHLY BENEFICIAL PROJECT especially if they win!

    THERE ARE NO DANGEROUS RADIATION, NO TOXIC WASTE PROBLEM BUT A LOT OF TOXIC, RADIOACTIVE POLITICIANS with a lot of innocent naive brainwashed followers.

    Dr Looi.

    ReplyDelete
  3. REMEMBER THE "WHITE GAS BULBS" OR RATHER KEROSENE GAS MANTLES MADE IN GERMANY?

    THESE WERE USED IN THOSE LANTERNS WHICH GIVE OFF A VERY BRIGHT WHITE LIGHT AND WERE UNIVERSALLY USED BY ALL STREET HAWKERS IN THE WHOLE OF MALAYSIA IN THE 60s AND 70s?

    THESE GAS MANTLES ARE MADE OF FABRIC SOAKED IN THORIUM-232 MIXED WITH A LITTLE CERIUM. AND AFTER THE INITIAL "FIRING" IT BECOMES ALMOST PURE THORIUM DIOXIDE.

    IN THE BURNING KEROSENE VAPOUR, THE TEMPERATURE CAN REACH OVER 1,000 DEGREES CENTIGRADE.

    MILLIONS OF MALAYSIANS IN THE PAST HAD HELD THESE "DANGEROUS, RADIOACTIVE" THORIUM GAS MANTLES IN THEIR HANDS.

    THESE ARE STILL BEING SOLD FREELY AND WITHOUT ANY SPECIAL LICENSE FROM AELB.

    REMEMBER THORIUM DIOXIDE HAS A SPECIFIC ACTIVITY OF 3,585 Bq/g ! THE "WASTE" FROM LYNAS IS ONLY 6 Bq/g.

    WHY ARE FOLKS FROM THE ANTI-LYNAS CAMP SO FRIGHTEN OF 6 Bq/g FROM LYNAS WASTE WHILE NOT WORRIED ABOUT THE 3,585 Bq/g OF RADIATION FROM THEIR KEROSENE LAMP ?


    Dr Looi
    *

    ReplyDelete
  4. *
    Quote: Anti-Lynas:
    "Bukit merah (malaysia), bopal (india), chenobly (russia) and every other industries always has the same vision until it went bad." Unquote.


    "TITANIC (BRITAIN) death = 1,496; THE EMPRESS OF IRELAND (CANADA) death = 1,012; FERRY DONA PAZ (PHILLIPINES) death = 4,340; STAR FERRY (SCANDINAVIA) death = 159; FERRY ESTONIA, death = 852 and the Costa Concordia and every other passenger ship industry has the same vision until it went bad.

    SO USING THE SAME PERVERTED UNINTELLIGENT NONSENSICAL NONPHYSICAL LOGIC,

    STOP ALL PASSENGER SHIPS FROM SAILING IN THE EVER DANGEROUS SEAS !!!!!

    Dato' Dr Looi

    *

    http://www.youtube.com/watch?feature=player_detailpage&v=0MFxBkxNX6g

    ReplyDelete
  5. 1. Malaysian Journal of Nuclear and Related Technology

    THE ANNUAL DOSE RATE EXPOSURE FROM MALAYSIAN

    CLAY BRICK HOUSE = 0.43 mSv/year

    (215 x Lynas Worst Case Scenario)


    2. SLEEPIN IN WOODEN HOUSE = 0.20 mSv/yr

    (100x Lynas worst case)


    3. SLAG BRICK AND GRANITE HOUSE = up to 2.0 mSv/yr

    (1,000x Lynas worst case)


    SO TO ALL ANTI-LYNAS FOLKS, YOU SHOULD PITCH UP A TENT NEXT TO THE LYNAS PLANT AND SEND YOUR ENTIRE FAMILY TO LIVE NEXT TO LYNAS AS THIS IS HUNDREDS OF TIMES LESS RADIOACTIVE THAN LIVING IN YOUR PRESENT WOODEN OR BRICK HOUSES !



    Dato' Dr Looi
    *
    http://www.youtube.com/watch?v=kjT1kUAy_08&feature=player_detailpage

    ReplyDelete
  6. Interesting. I am working on an idea at the moment inspired by a paper written in 2007 at Tel Aviv University ie using potassium 40 for neural imaging.
    It seems that despite the data being biologically useful the detectors aren't yet sensitive enough although there are workarounds such as using a bismuth core GM tube (thanks to Soviet era tech!) or a detector of my own design which could be more efficient.


    ReplyDelete

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