India building an 80 MWe Pressurised Water Reactor (PWR ) at Kalpakkam near Chennai which marks the beginning of its indigenous PWR capability,
• (p/t)Pressurized water reactors (PWRs, called VVER in Russia) constitute a majority of all western nuclear power plants and are one of two types of light water reactor (LWR), the other type being boiling water reactors (BWRs)
• PWR's were originally designed to serve as nuclear submarine power plants and
1. were used in the original design of the first commercial power plant at Shippingport Atomic Power Station(USA)
2. An identical PWR of the same capacity would propel the indigenous nuclear-powered submarine INS Arihant that was launched on July 26.
3. The two PWRs were built by the Bhabha Atomic Research Centre (BARC).
• Enriched uranium would fuel them, and light water was both coolant and moderator.
• The Rare Materials Project at Ratnahalli, near Mysore, produced the enriched uranium.
• India also has two Light Water Reactors that use enriched uranium as fuel, and light water as coolant and moderator .
OTHER REACTORS
• The Pressurised Heavy Water Reactors (PHWRs), which use natural uranium as fuel,and heavy water (D2O) as coolant and moderator.
1. India has 15 Pressurised Heavy Water Reactors — PHWRs
• The FBRs would use plutonium-uranium oxide as fuel.
• The AHWR, to be built, would have thorium as fuel.
• Arihant was a joint project of the DAE, the Navy and the DRDO.
URANIUM MINES
• The capacity of the mill at Jaduguda in Jharkhand, which converted natural uranium into yellow cake, had been augmented.
• Another mill at Turamdih, also in Jharkhand, was commissioned and its production of yellow cake was going up.
• The uranium mine and the mill, which were under construction at Tummlapalle in Kadapa district in Andhra Pradesh, would go on stream in 2013.
• Exploration mining was taking place at Gogi in Karnataka.
New projects
• The Department of Atomic Energy (DAE) was looking forward to the start of the construction of four PHWRs of 700 MWe each, for which the Union government had given approval.
• Three new reactors — two units at the Rajasthan Atomic Power Station (RAPS-5 and 6) and the fourth unit at Kaiga in Karnataka — would be commissioned in a phased manner between this year and next year,
CONCEPT
WHAT HAPPENS INSIDE NUCLEAR REACTOR
Nuclear reactors generate energy through Nuclear fission, the process by which an atomic nucleus splits into two or more smaller nuclei.
• During fission, a small amount of mass is converted into energy, which can be used to power a generator to create electricity.
• In order to harness this energy, a controlled chain reaction is required for fission to take place.
1. (Chain Reaction)When a uranium nucleus in a reactor splits, it produces two or more neutrons that can then be absorbed by other nuclei, causing them to undergo fission as well.
2. More neutrons are released in turn and continuous fission is achieved.
WHY MODERATOR IS REQUIRED
• Neutrons produced by fission have high energies and move extremely quickly.
1. These so-called fast neutrons do not cause fission as efficiently as slower-moving ones so they are slowed down in most reactors by the process of moderation.
• A liquid or gas moderator, commonly water or helium, cools the neutrons to optimum energies for causing fission.
• These slower neutrons are also called thermal neutrons because they are brought to the same temperature as the surrounding coolant.
CASE OF BREEDER REACTOR
In contrast to most normal nuclear reactors, however, a fast reactor uses a coolant that is not an efficient moderator, such as liquid sodium, so its neutrons remain high-energy.
RELEVANCE ?
Although these fast neutrons are not as good at causing fission, they are readily captured by an isotope of uranium (U238), which then becomes plutonium (Pu239).
• This plutonium isotope can be reprocessed and used as more reactor fuel or in the production of nuclear weapons.
• Reactors can be designed to maximize plutonium production, and
• These reactors are called breeder reactors because in some cases they actually produce more fuel than they consume.
WHAT MAKES BREEDER REACTOR POSSIBLE ?
Breeder reactors are possible because of the proportion of uranium isotopes that exist in nature.
• Natural uranium consists primarily of U238, which does not fission readily, and U235, which does. Natural uranium is unsuitable for use in a nuclear reactor, however, because it is only 0.72 percent U235, which is not enough to sustain a chain reaction.
• Commercial nuclear reactors normally use uranium fuel that has had its U235 content enriched to somewhere between 3 and 8 percent by weight. Although the U235 does most of the fissioning, more than 90 percent of the atoms in the fuel are U238--potential neutron capture targets and future plutonium atoms.
• Pu239, which is created when U238 captures a neutron, forms U239 and then undergoes two beta decays, happens to be even better at fissioning than U235.
COCEPT OF FAST BREEDER REACTOR
Pu239 is formed in every reactor and also fissions as the reactor operates. In fact, a nuclear reactor can derive a significant amount of energy from such plutonium fission. But because this plutonium fissions, it reduces the amount that is left in the fuel
• To maximize plutonium production, therefore, a reactor must create as much plutonium as possible while minimizing the amount that splits. This is why many breeder reactors are also fast reactors.
1. Fast neutrons are ideal for plutonium production because they are easily absorbed by U238 to create Pu239, and
2. They cause less fission than thermal neutrons.
3. Some fast breeder reactors can generate up to 30 percent more fuel than they use.
CONERNS INVOLVED
Creating extra fuel in nuclear reactors, however, is not without its concerns:
1. One is that the plutonium produced can be removed and used in nuclear weapons.
2. Another is that, to extract the plutonium, the fuel must be reprocessed, creating radioactive waste and potentially high radiation exposures.
3. In the world, only India, Russia, Japan and China currently have operational fast breeder reactor programs; the U.K., France and Germany have effectively shut down theirs.
Milestone in stem cell research ( in induced pluripotent stem (iPS) cells )
BREAKTHROUGH
• Research on reprogramming adult cells to make them behave like embryonic stem cells crossed a milestone recently when two Chinese teams succeeded in producing mouse pups using such cells.
• ie pluripotency of iPS cells has been proved to a certain extent
SCIENTIST
• Qi Zhous of the Chinese Academy of Science &
• Shaorong Gao from the National Institute of Biological Sciences in Beijing,
CONCEPTUAL UNERSTANDING
Stem cells are cells found in most, if not all, multi cellular organisms. They are characterized by the ability to renew themselves through mitotic cell division and differentiating into a diverse range of specialized cell types.
• Research in the stem cell field grew out of findings by Canadian scientists Ernest A. McCulloch and James E. Till in the 1960s.[1][2]
• The two broad types of mammalian stem cells are:
1. embryonic stem cells that are isolated from the inner cell mass of blastocysts(p/t)(stage of development of embryo ), and
2. adult stem cells that are found in adult tissues.
• HOW THEY WORK
1. In a developing embryo, stem cells can differentiate into all of the specialized embryonic tissues.
2. In adult organisms, stem cells and progenitor cells act as a repair system for the body, replenishing specialized cells, but also maintain the normal turnover of regenerative organs, such as blood, skin, or intestinal tissues.
• Stem cells can now be grown and transformed into specialized cells with characteristics consistent with cells of various tissues such as muscles or nerves through cell culture.
1. Highly plastic adult stem cells from a variety of sources, including umbilical cord blood and bone marrow, are routinely used in medical therapies.
2. Embryonic cell lines and autologous embryonic stem cells generated through therapeutic cloning have also been proposed as promising candidates for future therapies.[3]
TERMINIOLOGY
PLURIPOTENCY
• In cell biology, the definition of pluripotency has come to refer to a stem cell that has the potential to differentiate into any of the three germ layers:
1. (p/t)) endoderm (interior stomach lining, gastrointestinal tract, the lungs),
2. (p/t) mesoderm (muscle, bone, blood, urogenital), or
3. (p/t) ectoderm (epidermal tissues and nervous system).
• Pluripotent stem cells can give rise to any fetal or adult cell type.
1. However, alone they cannot develop into a fetal or adult animal because they lack the potential to contribute to extraembryonic tissue, such as the placenta (recent research has changed this notion )
SOMATIC CELL (soma derieved from greek word soma ie body )
• Somatic cells (diploid) are any cells forming the body of an organism, as opposed to germline cells.
• In mammals, germline cells (also known as "gametes") are the spermatozoa and ova which fuse during fertilization to produce a cell called a zygote, from which the entire mammalian embryo develops.
• Every other cell type in the mammalian body—apart from the sperm and ova, the cells from which they are made (gametocytes) and undifferentiated stem cells—is a somatic cell:
• Internal organs, skin, bones, blood, and connective tissue are all made up of somatic cells.
UNDERSTANDING LATEST DEVELOPMENT
Ever since induced pluripotent stem (iPS) cells were produced in 2006 by reprogramming adult cells,
• The unassailable evidence of their pluripotency ie, ability of the cells to behave like embryonic stem cells and form all of the 200-odd specialised cells — was lacking.
• The latest success in producing mouse pups using reprogrammed adult cells has taken research one step closer to proving the pluripotency of iPS cells.
HOW THEY ACHIEVE IT ?
• One team, headed by Qi Zhous (27 pups, including TINY) of the Chinese Academy of Science, and the other, led by Shaorong Gao (Four pups )from the National Institute of Biological Sciences in Beijing, were able to produce mouse pups using iPS cells injected into early-stage embryos that can only become the placenta and not develop into animals.
• The pups created by Qi Zhous passed the fundamental test of health
RELEVANCE
• Many scientists are turning to iPS cell technique to sidestep the ethical controversy of embryo destruction when somatic cell nuclear transfer (SCNT) technique is used.
• Also, unlike in the case of SCNT, human eggs are not required when iPS cells are used for making embryos.
• The technique is nearing maturity and may pave the way for creating cell lines to study genetic diseases.
PROBLEMS
• The Qi Zhous team used retroviral vectors to introduce four genes to reprogramme adult cells.
1. Retroviruses are known to induce cancer in mammals.
2. Though some studies have succeeded in inducing pluripotency without using these viruses, more research remains to be done.
• Similarly, oncogenes were used for reprogramming adult cells. This again raises the possibility of cancer formation when the pluripotent cells are introduced into an animal.
• Skin cells are routinely used for making iPS cells. Though available in plenty, turning back their clocks to make them pluripotent is a big challenge.
• Both the Scientists had hence used more pliable cells taken from late-stage embryos. This approach will not be useful if the iPS technique is used for patient-matched therapeutic applications.
NPCIL to start building two PHWRs
NPCIL Nuclear Power Corporation of India Limited (NPCIL)
Chairman S.K. Jain.
· The ground-breaking ceremony for the construction of two indigenous nuclear reactors of 700 MWe capacity will take place by next month end at Kakrapar in Gujarat
· This is the first time the NPCIL will be building the two Pressurised Heavy Water Reactors (PHWRs) of 700 MWe. So far, it has built only PHWRs of 220 MWe or 540 MWe capacity.
· The indigenous PHWRs use natural uranium as fuel and heavy water as both the coolant and moderator.
Big push to R&D in renewable energy To promote generation of energy from renewable sources, the Central Government has decided to invest Rs. 500 crore on its research, development and technology demonstration during the XI Plan.
· These projects( in total 77 ) include development of high efficiency solar cells, hydrogen and fuel cells; solar photovoltaic and solar thermal power generation; high-rate bio-methanation; and medium and large capacity biogas plants for energy and power generation
· Rs.303 crore had been released to States and Union Territories
· India
· Two more plants of 2 MW capacity each have been set up in Karnataka’s Kolar and Belgaum
The Jawaharlal Nehru National Solar Mission
· Under the mission, three major steps are proposed —
1. create volumes which will allow domestic manufacture;
2. support R&D to reduce material consumption and improve efficiency;
3. and announce long-term policy to purchase power.
· The first phase target of the Mission
SITES FOR NUCLEAR POWER PLANTS
- U.S.-led consortia at Chhayamithi Virdi in
Gujarat and Kovvada in(AP), seek to source technology and material for large nuclear power plants.
Russia has been given a site at Haripur inWest Bengal , besides Koodankulam. more broad-based than those with theU.S.
- French company Areva will start work at Jaitapur in
Maharashtra . seek to source technology and material for large nuclear power plants.
M.P. to get its first nuclear power project
The Nuclear Power Corporation of India Ltd (NPCIL) has decided to set up an atomic station(first) to generate 1400 MW power in at Chutka Mandla district in Madhya Pradesh,
Hogs to be reintroduced in forest
Findings of Chandrayan 1
Chandrayaan-1’s X-ray Spectrometer (C1XS)
How it works
· The miniature C1XS instrument investigated the lunar surface using an effect whereby X-ray illumination from the sun causes rocks to fluoresce, emitting light at a different wavelength.
· This re-emitted light contains spectral peaks that are characteristic of elements contained in the rock, revealing its composition.
· It added that the spectral resolution of 50 km was much better than previous missions.
What it Detected
· In its 10-month orbit around the moon, Chandrayaan-1’s X-ray Spectrometer (C1XS) has detected titanium, confirmed the presence of calcium, and gathered the most accurate measurements yet of magnesium, aluminium and iron on the lunar surface.
· While C1XS detected magnesium, aluminium and silicon during normal conditions, the instrument could detect calcium, iron, titanium, sodium and potassium in key areas in the southern hemisphere and on the far side of the Moon during the solar flares
· Previous lunar probes detected some of these minerals on the lunar surface, but none as accurately as the C1XS X-ray spectrometer,
J.N. Goswami, director of the Physical Research Laboratory, Ahmedabad, and principal scientist for Chandrayaan-1,.
Contribution of Dr BorlaugGene pyramiding, gene deployment and shuttle breeding strategies to increase yield and develop leaf rust-resistant varieties were among Dr. Borlaug’s revolutionary contributions.
The man who devoted a lifetime fighting hunger was as concerned at the threat to agriculture from the virulent stem rust Ug99 as the challenge of enlarging the food basket by introducing new nutritious crops.
ISSUES RELATED TO BIO DIVERSITY Hogs to be reintroduced in forest
· West Bengal’s Forest Department has decided to reintroduce the critically endangered pygmy hog in north Bengal ’s Gorumara forest.
· After the successful release of the hunched, barely two-feet long, furry hogs into the wild at the Sonai Rupai Wildlife Sanctuary and Nameri National Park in Assam in 2008, the Forest Department wants to replicate the experiment in the forests of north Bengal, since it falls in the region that is the original home of the wild suids (pigs),
· Earlier, they were easily located in Nepal , Bhutan and India , but they are not found anywhere other than Assam
Bhuvan
The Indian Space Research Organisation (ISRO) launch its own version of Google Earth ‘Called ‘Bhuvan,’ the new web-based 3D mapping tool
· It uses images taken over a year ago by ISRO’s seven remote sensing satellites, including Cartosat-1 and Cartosat-2. The satellites can capture images of objects as small as a car on a road
· This would provide a sharper picture of Indian terrain barring sensitive locations such as military and nuclear installations & offers tools to measure horizontal, vertical and aerial distances.
· The degree of resolution showcased is based on the level of popularity of a place or an area. Most of the terrain is covered up to a resolution of at least six metres. The least spatial resolution is 55 metres.
· The user can also navigate through 3D viewing environment. One can “fly” to destinations of choice and even draw 3D objects such as placing of expressive 3D models, 3D polygons and boxes.
· Later speaking to journalists, ISRO Chairman said the space agency had started the preparations for a mission to Mars within the next six years. It was looking at launch opportunities between 2013 and 2015.
HUBBLE’S CONSTANT
Defination
Hubble's constant is the speed at which a distant galactic object is moving away from us divided by the distance of the object from the telescope or the earth.
Relevance
It can be shown by simple arithmetic that the reciprocal of Hubble's constant is the age of the universe based on the Big Bang theory. Hence it is necessary to refine it to a point of perfection to arrive at an accurate figure for the age of the universe.
How it is calculated
· The Hubble constant using a relationship between the absolute brightness of a type of variable star (whose brightness varied) called Cepheid and its period of variability.
· The method measured the observed brightness and periods of these stars in distant galaxies.
1. Comparing the observed brightness with the absolute brightness inferred from the period allows one to measure the distance to the object and hence estimate the Hubble constant.
Nasa's Spitzer infrared space telescope (launch in 2003) will refined Hubble's constant (p/t)
· Spitzer's instruments detect everything between 3.6 to 160 microns. To detect 160 micron light (longest wavelength of infrared light ), without being swamped by the internal thermal glow of the instrument itself, the telescope must be chilled to just a few degrees above absolute zero.
· At shorter wavelengths it can operate at progressively warmer temperatures. Warm Spitzer will address many of the same science questions as before including refining estimates of Hubble's constant, or the rate at which our universe is stretching apart.
1. The advantage of doing this in infrared is that the observed brightness will not be affected by the interstellardust between us and the star, and hence the distance measurements will be much more robust.
· Since its launch in 2003, Spitzer has made many discoveries including planet forming discs around stars, the composition of materials that make up comets, hidden black holes, galaxies billions of light-years away and more.
