ALTHOUGH THE JAPANESE INCIDENT NOW EQUATES TO CHERNOBYL ON THE INTERNATIONAL SCALE, THE TWO ACCIDENTS ARE DIFFERENT IN A NUMBER OF IMPORTANT WAYS. IN CHERNOBYL IT WAS THE REACTOR CORE ITSELF THAT EXPLODED, RELEASING A HUGE AMOUNT OF RADIOACTIVE MATERIAL IN A VERY SHORT SPACE OF TIME. FUKUSHIMA EXPERIENCED A LESS CRITICAL HYDROGEN EXPLOSION.
CHEMISTRY AND PHYSICS PROFESSOR STEPHEN LINCOLN, OF ADELAIDE UNIVERSITY, SAID THE MAIN WORRY WAS THE FOOD STOCK IN THE OCEAN, WHERE MUCH OF THE RADIOACTIVE MATERIAL WAS BEING RELEASED .WHILE ONE OF THE RADIOACTIVE SUBSTANCES, IODINE-131, HAD A HALF-LIFE OF NINE DAYS, TWO OTHERS - CAESIUM-137 AND STRONTIUM-90 - COULD BE MORE HARMFUL IN THE LONG TERM AS THEY HAD HALF-LIVES OF 30 YEARS, HESAID.
A HALF-LIFE IS THE TIME TAKEN FOR HALF OF A SAMPLE OF A RADIOACTIVE ISOTOPE TO DECAY INTO OTHER MATERIALS.
"[PEOPLE] SHOULD NOT VENTURE INTO THE OCEAN [WHERE THE RADIOACTIVE MATERIALS ARE BEING RELEASED]; THEY SHOULD NOT EAT ANY FISH OR SEAWEED FROM THE OCEAN. "THE LIVING SPECIES LIKELY TO BE MOST AFFECTED ARE SHELLFISH BECAUSE THEY ARE STATIONARY WHEREAS FISH THAT SWIM MAY PASS THROUGH THE AREA AND OUT AGAIN. THE SHELLFISH SUCH AS MUSSELS, OYSTERS AND CLAMS CERTAINLY ACCUMULATE HIGH LEVELS OF RADIOACTIVITY. "IF THEY CAN STOP THE LEAKS, THEN THE OCEAN CAN DISPERSE THE RADIOACTIVITY UNTIL IT BECOMES NO MORE THAN BACKGROUND."
IMPACT OF LEAKS
THE NUCLEAR SAFETY COMMISSION OF JAPAN ANNOUNCED IN A STATEMENT THAT THE CRISIS LEVEL AT THE FUKUSHIMA DAIICHI PLANT WAS BEING RAISED, ADDING THAT IT WAS A PRELIMINARY ASSESSMENT WHICH REQUIRED FURTHER TECHNICAL EVALUATION BY SPECIALISTS.
THE LEVEL SEVEN SIGNIFIES A "MAJOR ACCIDENT" WITH "WIDER CONSEQUENCES" THAN THE PREVIOUS LEVEL, OFFICIALS SAY.
"WE HAVE UPGRADED THE SEVERITY LEVEL TO SEVEN AS THE IMPACT OF RADIATION LEAKS HAS BEEN WIDESPREAD FROM THE AIR, VEGETABLES, TAP WATER AND THE OCEAN," SAID MINORU OOGODA OF JAPAN'S NUCLEAR AND INDUSTRIAL SAFETY AGENCY (NISA), THE GOVERNMENT'S NUCLEAR WATCHDOG. REPORTING THE COMMISSION'S DECISION, THE IAEA SAID PREVIOUS LEVEL FIVE RATINGS HAD BEEN PROVIDED SEPARATELY FOR ACCIDENTS AT REACTORS 1, 2 AND 3 BUT HAD NOW BEEN COMBINED AS A SINGLE EVENT. ANOTHER AFFECTED UNIT, REACTOR 4, HAS RETAINED ITS LEVEL THREE RATING, IT SAID. ONE OFFICIAL FROM TEPCO SAID THAT RADIATION LEAKS HAD NOT STOPPED COMPLETELY AND COULD EVENTUALLY EXCEED THOSE AT CHERNOBYL, REUTERS NEWS AGENCY REPORTED. HOWEVER, A NUCLEAR SAFETY AGENCY SPOKESMAN TOLD REPORTERS THE LEAKS WERE STILL SMALL COMPARED TO THOSE AT THE PLANT IN UKRAINE, THEN PART OF THE SOVIET UNION. "IN TERMS OF VOLUME OF RADIOACTIVE MATERIALS RELEASED, OUR ESTIMATE SHOWS IT IS ABOUT 10% OF WHAT WAS RELEASED BY CHERNOBYL," HE SAID. THE DECISION TO RAISE THE THREAT LEVEL WAS MADE AFTER RADIATION OF A TOTAL UP TO 630,000 TERABEQUERELS HAD BEEN ESTIMATED AT THE STRICKEN PLANT.
WORLD'S WORST NUCLEAR INCIDENTS
LEVEL 7 ACCIDENTS ON THE INTERNATIONAL NUCLEAR EVENT SCALE CORRESPOND TO THE RELEASE INTO THE EXTERNAL ENVIRONMENT OF RADIOACTIVE MATERIALS EQUAL TO MORE THAN TENS OF THOUSANDS OF TERABECQUERELS OF RADIOACTIVE IODINE 131. ONE TERABECQUEREL EQUALS 1 TRILLION BECQUERELS.
LEVEL 7: CHERNOBYL, UKRAINE, 1986 - EXPLOSION AND FIRE IN OPERATIONAL REACTOR, FALLOUT OVER THOUSANDS OF SQUARE KILOMETRES, POSSIBLE 4,000 CANCER CASES
LEVEL 7: FUKUSHIMA, 2011 - TSUNAMI AND POSSIBLY EARTHQUAKE DAMAGE FROM SEISMIC ACTIVITY BEYOND PLANT DESIGN, LEADING TO...?
LEVEL 6: KYSHTYM, RUSSIA, 1957 - EXPLOSION IN WASTE TANK LEADING TO HUNDREDS OF CANCER CASES, CONTAMINATION OVER HUNDREDS OF SQUARE KILOMETRES.
LEVEL 5: WINDSCALE, UK, 1957 - FIRE IN OPERATING REACTOR, RELEASE OF CONTAMINATION IN LOCAL AREA, POSSIBLE 240 CANCER CASES.
LEVEL 5: THREE MILE ISLAND, US, 1979 - INSTRUMENT FAULT LEADING TO LARGE-SCALE MELTDOWN, SEVERE DAMAGE TO REACTOR CORE.
Milind Phadke
+919890317557
