1. Seminar Presentation On + NUCLEAR BATTERIES - A Portable Energy Source www.engineersportal.in

2. CONTENTS 1.Why Nuclear Battery? 2.Historical Developments. 3.Understanding The Terms Used. 4.Energy Production Mechanism. 5.Fuel Consideration. 6.Applications 7.Advantages 8.Disadvantages 9.Conclusion www.engineersportal.in

3. Q. WHY NUCLEAR BATTERY ??? www.engineersportal.in

4. ANSWER:  Chemical batteries require frequent replacements and are bulky.  Fuel and Solar cells are expensive and requires sunlight respectively.  Need for compact, reliable, light weight and long life power supplies.  Nuclear battery uses emission from radioisotope to generate electricity so there is no fear of hazardous radiations.  Nuclear batteries have lifespan up to decades.  Can be used in easily inaccessible in extreme conditions and reduce the rate of replacements. www.engineersportal.in

5. HISTORICAL DEVELOPMENTS 1.The idea of nuclear battery was introduced in the beginning of 1950, and was patented on March 3 rd, 1959 to Tracer Lab. 2.A radio isotope electric power system was developed by inventor Paul Brown which was a scientific break through in nuclear power. 3.Brown’s first prototype power cell produced 100,000 times powerful energy than the most powerful thermal battery yet in existence. www.engineersportal.in

6. UNDERSTANDING THE TERMS USED RADIOISOTOPES : Radioisotopes are artificially produced, unstable atoms of a chemical elements, which have a different number of neutrons in the nucleus, but the same number of protons and the same chemical properties. Alpha- These are fast moving helium atoms. They have high energy, typically in the MeV range. They also are magnetic in nature. Beta- These are fast moving electrons. They typically have energies in the range of a few hundred KeV to several MeV. Gamma- These are photons, just like light, except of much higher energy. www.engineersportal.in

7. ENERGY PRODUCTION MECHANISM www.engineersportal.in

8. 1. BETAVOLTAICS I.Betavoltaics is an alternative energy technology that promises vastly extended battery life and power density over current technologies. II.Uses energy from beta particle. III.Beta particles are emitted by radioactive gas is captured in silicon wafer coated with diode material. IV.It is similar to the mechanism of converting sunlight into electricity in a solar panel. V.Absorbed radiations creates electron-hole pair which in turn results in the generation of electric current. www.engineersportal.in

9. REPRESENTATION OF BASIC BETA VOLTAIC CONVERSION Electrode A (P-region) has a positive potential while electrode B (N-region) is negative. www.engineersportal.in

10. 2. DIRECT CHARGING GENERATORS This method makes use of kinetic energy as well as magnetic property of alpha particles to generate current. It consists of a core composed of radioactive elements. Primary generator consists of a LC tank circuit. LC circuit produces the oscillations required for transformer operation. www.engineersportal.in

11. SCHEMATIC DIAGRAM OF AN LC RESONANT CIRCUIT 1.Capacitor 2.Inductor 3.Core with radio active elements 4.Transformer T primary winding 5.Resistance 6.Secondary winding 7.Load www.engineersportal.in

12. EQUIVALENT CIRCUIT DIAGRAM OF DIRECT CHARGING GENERATOR 1.Capacitor 2.Inductor 3.Core with radioactive elements 4.Transformer T primary winding 5.Resistance 6.Secondary winding 7.Load www.engineersportal.in

13. FUEL CONSIDERATION The major criterions considered in the selection of fuels are:  Avoidance of gamma in the decay chain Ra-226 produces Bi-214. Strong gamma radiation. Shielding makes it bulky.  Half life( Should be more)  Cost should be less.  Any radioisotope in the form of a solid that gives off alpha or beta particles can be utilized in the nuclear battery.  The most powerful source of energy known is radium-226.  However Strontium-90 may also be used in this Battery www.engineersportal.in

14. APPLICATIONS 1.SPACE APPLICATIONS : Unaffected by long period of darkness and radiation belts like Van- Allen belt. Compact and lighter in weight. Can avoid refrigeration / heating equipments required for storage batteries. High power for long time independent of atmospheric conditions. NASA is trying to harness this technology in sace applications. www.engineersportal.in

15. App. Continue… 2. MEDICAL APPLICATIONS: In cardiac pacemakers. Batteries should have reliability and longevity to avoid frequent replacements. 3. MOBILE DEVICES : Nuclear powered laptop battery Xcell-N has 7000-8000 times more life than normal laptop batteries. 4. AUTOMOBILES : No need for frequent recharging as in case of present electric vehicles. www.engineersportal.in

16. ADVANTAGES Life span – minimum of 10 years. Reliable electricity. Amount of energy obtained is very high. Lighter with high energy density. Less waste generation. Reduces green house and associated effects. Fuel used is the nuclear waste from nuclear fission. www.engineersportal.in

17. DISADVANTAGES High initial cost of production as its in the experimental stage. Regional and country – specific laws regarding use and disposal of radioactive fuels. To gain social acceptance. www.engineersportal.in

18. CONCLUSION Small compact devices of future require small batteries. Nuclear battery increases functionality, reliability and longevity. Until final disposal all Radiation Protection Standards must be met. Batteries of the near future. www.engineersportal.in