Nuclear Battery

A PRESENTATION ON

NUCLEAR BATTERY

Submitted To: SSS Submitted By:Mr. Dhiraj Kumar Singh NIKHIL NAMA EE 8th Sem.

ContentWhy Nuclear Batteries?Historical DevelopmentEnergy Production Mechanism BetavoltaicEnergy Conversion MechanismsDirect Charging GeneratorFuel ConsiderationAdvantagesDrawbacksApplications

Why Nuclear Battery?Need for compact reliable light weight and

self-contained power supplies.Chemical batteries require frequent

replacements and are bulky.Nuclear reactors offer economical and

technical problems.Fuel and Solar cells are expensive and

requires sunlight respectively.

Nuclear batteries have lifespan upto decades and nearly 200 times more efficient.

Do not rely on nuclear reaction , so no radioactive wastes.

Uses emissions from radioactive isotope to generate electricity.

Can be used in inaccessible and extreme conditions.

HISTORICAL DEVELOPMENTSIdea was introduced in 1950 and patented to

Tracer Lab.Radioisotope electric power system

developed by Paul Brown.He organized an approach to harness energy

from the magnetic field of alpha and beta particles using Radium-226.

Low efficiency due to loss of electrons.

ENERGY PRODUCTION MECHANISMS Betavoltaics :

Alternative energy technology. Provides extended battery life and power

density.Uses energy from beta particles.Beta particles from radioactive gas captured in

Si wafer coated with diode material.Absorbed radiation creates electron-hole pair.Results in the generation of electric current.

Representation of basic beta voltaic conversion

The Energy Conversion Mechanism

Before the radioactive source is introduced , no current flows as the electrical forces are in equilibrium.

As a beta emitter is introduced , electrons are knocked out by its energy.

Generates electron-hole pairs in the junction.When beta particle imparts more than

ionization potential the electron rises to a higher level.

Fermi voltage established between the electrodes.Potential difference drives electrons from electrode

A through the load where they give up the energy.Electron is then driven into electrode B to

recombine with a junction ion.Betavoltaics does not have solar-cell efficiency.Electrons shoot out in all directions; hence lost.Porous Si diodes with pits provide a 3-D surface

thereby increasing the efficiency.

Schematic Diagram of an LC resonant circuit

3 – capacitor 5 – inductor7 – core with radioactive elements9 – transformer T primary winding11 – resistance

WorkingOscillations induced in LCR circuit damp out

due to loss of energy.Here energy is imparted to the alpha particles

during the decay of elements in the core.This energy is introduced to circuit when alpha

particles are absorbed by the inductor.Oscillations sustain until amount of energy

absorbed=amount of energy dissipated in ohmic resistance.

This excess energy is delivered to the load connected across transformer T secondary winding.

FUEL CONSIDERATIONSAvoiding gamma rays in decay chain.

Ra-226 produces Bi-214.Strong gamma radiation.Shielding makes it bulky.

Half life.Particle range.Cost.

ADVANTAGES

Life span- minimum of 10 years.Reliable electricity.Amount of energy highest.Lighter with high energy density.Efficient; less waste generation.Reduces green house and associated effects.Fuel used is the nuclear waste from nuclear

fission.

DRAWBACKSHigh initial cost of production as its in the

experimental stageEnergy conversion methodologies are not

much advanced.Regional and country-specific laws regarding

use and disposal of radioactive fuels.To gain social acceptance.

APPLICATIONSSpace applications: Unaffected by long period of darkness and

radiation belts like Van-Allen belt. Compact and lighter in weight. Can avoid heating equipments required for

storage batteries. High power for long time independent of

atmospheric conditions. NASA is trying to harness this technology in

space applications.

Medical applications: In Cardiac pacemakers Batteries should have reliability and longevity

to avoid frequent replacements.

• Mobile devices: Nuclear powered laptop battery Xcell-N has

7000-8000 times more life. No need for charging, battery replacing.

Automobiles: In initial stages. No running short of fuel. Possibility of replacing ionic fuels with its

advantages.

• Under-water sea probes and sea sensors: In sensors working for long time. At inaccessible and extreme conditions. Use in coal mines and polar sensor applications too.

• For powering MEMS devices : in optical switches and smart dust sensors.

CONCLUSIONSmall compact devices of future require

small batteries.Nuclear batteries increase functionality,

reliability and longevity.Until final disposal all Radiation Protection

Standards must be met.Batteries of the near future.

THANK YOU