RADIOACTIVE! Sheryl Hoffmann

 Legislation  ARPNSA Safety Guide  Australian Curriculum  Theory  Practicals for middle school students  Practicals for senior school students SUMMARY

 Radiation Protection and Control Act 1982  Radiation Protection and Control (Ionising Radiation) Regulations 2000 (SA)  Part 6—Miscellaneous Division 1—Use of ionising radiation in schools 181—Interpretation (1) In this Division— the Code means “the Code of Practice for the Safe Use of Ionizing Radiation in Secondary Schools” (1986) published by the National Health and Medical Research Council, SA LEGISLATION

THE CODE

182—Use of radioactive substance etc in secondary school to be in accordance with Code (1) The use of a radioactive substance or apparatus in a secondary school must be in accordance with the Code. (2) A person in charge of a secondary school must ensure that at all times there is a person designated to act as the responsible teacher for the purposes of compliance with the Code. (3) If this regulation is not complied with, the person in charge of the school is guilty of an offence. SA LEGISLATION

GUIDELINES

Science Year 9 Science Understanding / Chemical sciences Content description All matter is made of atoms which are composed of protons, neutrons and electrons; natural radioactivity arises from the decay of nuclei in atoms AUSTRALIAN CURRICULUM

Elaborations describing and modelling the structure of atoms in terms of the nucleus, protons, neutrons and electrons comparing the mass and charge of protons, neutrons and electrons describing in simple terms how alpha and beta particles and gamma radiation are released from unstable atoms AUSTRALIAN CURRICULUM

Achievement Standard By the end of Year 9, students explain chemical processes and natural radioactivity in terms of atoms and energy transfers and describe examples of important chemical reactions. AUSTRALIAN CURRICULUM

WHAT IS RADIATION?

 Ionizing radiation has enough energy to cause chemical changes by breaking chemical bonds  The energy is absorbed by the surroundings  This can cause damage to living tissue IONIZING RADIATION

 Alpha particles – which include two protons & two neutrons  Beta particles – which are essentially electrons  Gamma Rays & X-Rays – which are pure energy (photons) 3 KINDS OF IONIZING RADIATION

Two measurements:  Activity  Exposure MEASURING RADIATION

 How much radiation is coming out of something  Unit: Becquerel (Bq).  The Becquerel counts how many particles or photons (in the case of wave radiation) are emitted per second by a source. 1Bq = 1 disintegration per second (a very small unit). ACTIVITY

EXPOSURE  Measures the effects of that radiation on anything that absorbs it  Units: Sievert (Sv) & milliSievert (mSv)

There are three ways to express radiation exposure:  Absorbed dose: the energy 'deposited' in a kilogram of a substance by a radiation source; measured in an international (SI) unit called the Gray (Gy).  Equivalent dose: relates the absorbed dose to the biological damage of the type of radiation. The absorbed dose is multiplied by radiation weighting factor (wR); measured in an international (SI) unit called the Sievert (Sv).  Effective dose: the equivalent dose multiplied by tissue weighting factor (wT) for the different harmful effects of radiation on different types of tissue. If more than one organ has been exposed, the overall effective dose is the sum of all the effective doses of all the exposed organs. The unit of effective dose is the Sievert (Sv). EXPOSURE

ACTIVITY & DOSE

Source of ExposureExposure General Australian background radiation 1.5 mSv per year Natural radiation at sea level in Australia (cosmic) 0.36mSv per year Chest X-ray0.02 mSv 7 hour flight 0.05 mSv Domestic airline pilot2 - 6 mSv per year Max occupational exposure allowed20 mSv (full body) Max public exposure allowed1 mSv Standard School demo0.01 mSv (to teacher’s hand) EXPOSURE

1.Appoint a Radiation Supervisor 2.Local Rules (see Annex 4) 3.Risk Assessment (see Annex 3) 4.Staff Induction 5.Students Age 6.Record Keeping 7.Storage 8.Disposal 9.Spills 10.Inspection & Wipe Test (Annex 5) ADMINISTRATIVE PROCEDURES

 Fold a clean, dry, paper tissue to make a small pad with an area about the size of the window of the radiation detector. Hold the tissue in forceps and gently wipe the pad over the surfaces of the source  Hold the radiation detector very close to, but not touching, the wiping surface of the tissue.  Count the radioactivity on the tissue for 2 minutes  If the count from the tissue is less than 1.5 times background, the source has passed the wipe test WIPE TEST (ANNEX 5)

1.WHAT ITEMS ARE RADIOACTIVE? 2.BACKGROUND RADIATION 3.TIME AND RADIATION EXPOSURE 4.DISTANCE AND RADIATION EXPOSURE 5.SHIELDING JUNIOR PRACTICALS

RADIATION IN THE HOME

BACKGROUND RADIATION

REDUCE TIME & REDUCE EXPOSURE Is it safe to wear this watch for 8 hours per day?

VASELINE GLASSWARE How long is it safe to sit 3m from this item?

1 Intensity α (distance ) 2 INVERSE SQUARE LAW

SHIELDING

 Cloud Chamber  Smoke Detector  Half-life Experiments  Protactinium Generator  Thoron Generator  Balloon  Caesium /Barium Generator SENIOR PRACTICALS

CLOUD CHAMBER

SMOKE DETECTOR

INSIDE A SMOKE DETECTOR

HOW A SMOKE DETECTOR WORKS The alpha particles pass between the two charged metal plates, causing air particles to ionise (split into positive and negative ions). The ions are attracted to the oppositely charged metal plates causing a current to flow. When smoke enters between the plates, some of the alpha particles are absorbed causing less ionisation to take place. This means a smaller than normal current flows so the alarm sounds.

URANIUM DECAY CHAIN

PROTACTINIUM GENERATOR

PASCO ISOTOPE GENERATOR KIT (BARIUM-137m)

THORON GENERATOR

BALLOON

HALF-LIFE

 NSW Chemical Safety in Schools  Wikipedia    add_ocr_gateway/radiation/radioisotopesrev3.shtml add_ocr_gateway/radiation/radioisotopesrev3.shtml  _isotope-generator-kit-barium-137-m/index.cfm _isotope-generator-kit-barium-137-m/index.cfm  Practical work using low-level radioactive materials available to the public, Ralph Whitcher, SSR June 2011, 92(341) 65 REFERENCES

COPY OF THIS POWERPOINT

Creative Commons This copyright work is licensed under a Creative Commons Attribution-Noncommercial 3.0 Australia licence. To view a copy of this licence, visit In essence, you are free to copy, communicate and adapt the work for non-commercial purposes, as long as you attribute the work to Sheryl Hoffmann and abide by the other licence terms. Contact information: Sheryl Hoffmann Phone: Fax: CREATIVE COMMONS