Decommissioning reactors should be an option -- Akahata editorial, November
18, 2001
Pipes of the emergency core cooling system of the No. 1 reactor of the
Hamaoka nuclear power plant in Shizuoka Prefecture (Chubu Electric Power
Co.) broke down and radioactive steam leaked inside the plant. It was found
out later that radioactive coolant leaked from a vessel containing the
control rod drive at the bottom of the the pressurizing vessel.
The breakdown of the pipes occurred precisely in the section in which the
company changed the design for the coolant system in 1993. The government,
however, did not check the safety of this change, and this shows how
inadequate government control of the safety of nuclear power plants is.
Unlike in the United States, no steps have been taken in Japan to control
the "water hammer" phenomenon, a possible cause of such accidents in boiling
water reactors.
Leak of coolant from the bottom of the pressurizing vessel took place in
1988, but no safety measures were implemented.
The crack in the bottom, if enlarged, could have caused a catastrophic
accident in the core of the reactor. The company detected the change in the
water temperature in July, but left it as it was for four months. This shows
how negligent the company is concerning the need for safety checks.
The government's Nuclear Safety Commission and other bodies have begun to
investigate the accident. However, objective investigation by an independent
body alone can get the results which can convince the people of the true cause of
the accident.
Previously, the government stated that a nuclear power plant will
technically survive 30 years. Now it says that partial repairs will prolong
their life to "60 years." The accidents at Hamaoka, 25 years in operation,
points to the superannuated nature of nuclear power plants.
The government and the electric power companies should get rid of the
"myth"that nuclear power plants are safe and thoroughly check all 28 hot
water reactors in Japan. Immediate inspections are necessary at aged
reactors. Based on the results, the government must take full steps to
ensure safety, including termination of operations and abolition of
reactors. (end)