Wednesday, April 30, 2008

யுரேனியம் செறிவூட்டும் ஆலையின் படங்கள்: ஈரான் வெளியிட்டுள்ளது.

மேற்கத்திய ஊடகங்கள் கூவி வந்த "ரகசிய ஆலை", "ரகசிய ஆலை" என்ற கூச்சலை நகைக்கும் படி ஈரான் தனது ஆலையின் முக்கிய பகுதிகளைப் பற்றிய புகைப்படங்களை வெளியிட்டுள்ளது.

யுரேனியத்தில் இரு வகையான கதிரியக்க தனிம பரிமாணங்கள் (Isotopes) உள்ளன. இவைகளின் அணு எடை எண் 235 மற்றும் 238 ஆகும். அணுசக்திக்கு பயன்படும் பரிமாணம் (அல்லது ஐசோடோப்) அதிக எடை உடையது (238). இந்த ஐசோடோப்புகளின் கலவையை ஒரு கலனில் போட்டு மிகவேகமாகச் சுற்றும் போது, அதிக எடை உடைய 238 ரக யுரேனியம், கலனின் விளிம்புகளில் சேகரமாகும், பின்பு அதனை விளிம்புபகுதிகளில் உறிஞ்சி எடுத்து பயன்படுத்திக் கொள்ளலாம்.

அந்த கலன்களுக்கு மையவிலக்கிகள் (centrifuges) என்று பெயர். அவைகளைத் தான் படங்களில் பார்க்கிறீர்கள்.




Located in the Iranian desert, the Natanz uranium-enrichment facility has been shrouded in secrecy. Many of the buildings there, visible in the aerial image from September 2002 on the far left, are now out of site, buried underground, near left. The site is also protected by anti-aircraft guns and barbed wire.




Thus, it was a surprise when President Mahmoud Ahmadinejad showed up on April 8 with television cameras in tow. The Iranian government put photographs of the visit on its press site. Mr. Ahmadinejad, left, was greeted by Gholamreza Aghazadeh, head of the Atomic Energy Organization of Iran. The agency runs Natanz and its operations to test and run nuclear centrifuges for the industrial-scale enrichment of uranium. The enriched material can make fuel for reactors or nuclear arms.

Jeffrey G. Lewis of the New America Foundation and R. Scott Kemp of Princeton University are among the analysts who have pored over the photographs and provided information for these captions.









Mr. Ahmadinejad and company toured an area of the underground halls where workers were preparing for the installation of new cascades of P-1 centrifuges. The mazes of overhead pipes will carry, among other things, gaseous uranium to feed the centrifuges.




Mr. Ahmadinejad and his entourage on their way out of the control room. On the photo's far left is Iran's defense minister, Mostafa Mohammad Najjar. His presence struck some analysts as odd given Iran's claim that its desert labors are entirely peaceful. The man in the photo's center is Mr. Aghazadeh, the head of the Atomic Energy Organization of Iran.




Mr. Ahmadinejad visited what appears to be a control room for centrifuges in the buried halls. Other photos in the series suggest that each monitor shows the status of a group of 164 centrifuges, known as a cascade. To date, Iran has installed 3,000 of the temperamental P-1 machines at Natanz, and recently began expanding that number to 9,000. Ultimately, it wants to have 54,000 centrifuges running around the clock, year after year.






In cavernous underground halls roughly half the size of the Pentagon, Mr. Ahmadinejad walked past rows of Iran's first generation of machines, known as the P-1, which was based on a Pakistani design sold on the nuclear black market. The temperamental machines broke down frequently in the early days. One Iranian study traced the failures to centrifuge assembly when technicians, working with bare hands, inadvertently left behind clusters of microbes. That minuscule weight was enough to throw the whirling machines off balance and cause them to malfunction.

Photo: Iran's Presidency Office/European Pressphoto Agency






Mr. Ahmadinejad shook hands with a worker in the underground centrifuge halls.



In the background is a silvery tank that holds tons of uranium hexafluoride, a highly toxic gas fed into the centrifuges for enrichment. The material, solid until heated just before usage, is made at site known as Isfahan and shipped to Natanz. Analysts say the silvery tank is similar to ones at the uranium conversion facility at Isfahan.



The tracks are used to transport large casks of uranium hexafluoride, the toxic gas fed into the centrifuges for enrichment.

Mr. Ahmadinejad and his retinue walked between rows of advanced centrifuges, in the foreground, and older P-1s in the background. The three pipes at the center of each centrifuge head carry uranium in various stages of processing, while the fourth pipe pumps air and stray gases out of the centrifuge casing, letting the rotor spin with as little friction as possible.

In the Pilot Fuel Enrichment Plant, one of the site's above-ground buildings, Mr. Ahmadinejad examined a carbon rotor for a new generation of centrifuges known as the IR-2, for Iranian second generation. A hand in the foreground holds what appears to be a bellows. The specialized part is difficult to manufacture but can link rotors together to make a long centrifuge that more quickly enriches uranium. A bellows is not believed to be used in the IR-2 machines now under development but may be part of an experimental program.

Mr. Aghazadeh, head of the Atomic Energy Organization of Iran, in front of empty stands for new centrifuges in the pilot plant. In the background, a cascade of IR-2 machines appears to be undergoing installation in an area that previously held P-1 centrifuges. Historically, the Iranians have used the pilot plant to test new centrifuge technology before its introduction into the buried halls, which are meant for mass production and industrial-scale enrichment.

In the aboveground Pilot Fuel Enrichment Plant, the woman showed Mr. Ahmadinejad a spiral groove bottom bearing, on which the centrifuge rotor spins. A second bearing is visible on the table. This bearing is the only point of physical contact between the spinning rotor and the outer casing, and it has proved problematic. Analysts call the image significant because Iran once suspended research on advanced centrifuges because of troubles making the bottom bearing.

After the visit, Mr. Ahmadinejad met with reporters, turning the tour of the secretive site into a media event.

நன்றி: Newyork Times

(புகைப் படங்களில் சில இப்பதிவில் தெரியாமல் போகலாம். அப்படியானால் அவைகள் காப்பிரைட் (காப்பு) செய்யப்பட்டது என்று பொருள். அவ்வாறெனில் நான் கொடுத்துள்ள இணைப்புக்குச் சென்று பார்த்துக் கொள்ளுங்கள்.)

1 comment:

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