Tuesday, April 26, 2011

Japan To Raise Exposure Levels for Children

Related: On the 25th anniversary of the Chernobyl explosion and meltdown of Unit 4, Russian president Dmitry Medvedev said, "the duty of the state is to tell the truth to its people" acknowledging that the former Soviet government did not do that during the deadly disaster and its aftermath. He also called for new international rules to be drafted to insure the safety of nuclear plants worldwide. The world community has pledged $780 million to build a new containment structure to replace a temporary sarcophagus that has begun to leak radiation. Russia donated $65.38 million to the effort. The United States has donated $240 million and recently pledged an additional $123 million to clean up the area. Tens of thousand of Ukranians had to be evacuated, including the town of Prypyat with a population of 50,000, never to return to the zone of national sacrifice which extends to a radius of 30kms from the reactor site. Ukraine abandoned nuclear weapons and gave up its stockpile of of highly enriched uranium, becoming a leader in nuclear safety. The US has responded by helping the country to construct a facility for nuclear medicine and research. Japan has called on Russian experience to aid its disposal of high level nuclear waste from the destroyed Fukushima power station.

{25.4.11}The Japanese government has made a decision to raise the permissible level of radiation exposure for children, who are more susceptible to radiation damage than adults, to 2 rems/year, primarily because their schools in Fukushima Prefecture are already experiencing high levels of fallout contamination. Seventy-five percent of schools monitored are reporting readings above the level for a "radiation controlled area". The 2 rem standard is twenty times the allowable U.S. exposure for the public. The government also converted the evacuation zone around the doomed plant to an exclusion zone as expected last week. People entering the zone without authorization can be fined up to $1200 or jailed for 30 days. Former residents of the area will be allowed a single two hour visit to gather their possessions and leave their former homes.

At the ruined Fukushima-daiichi plant, the reactor buildings have been structurally compromised by fire and temblors. Experts are worried that the tons of water being dumped into the buildings to cool the cores and fuel assemblies are putting an unbearable strain on the buildings. TEPCo has little choice but to continue to dump cooling water to prevent further melting and overheating. Damage to the reactor cores and fuel rods is said to be "enormous". Under these conditions, a molten slag can form at the bottom of a reactor vessel which damages seals and eventually burns its way through the steel vessel and containment walls, thus the derivation of the infamous "China Syndrome". High level fallout has so far prevented the installation of any closed loop cooling system. Meanwhile the irradiated cooling water is flowing into the surrounding environment, contaminating the sea and groundwater.