12 Apr (NucNet): Japan has ordered nuclear plant operators to put in place new safety measures by the end of April following the damage caused by a tsunami at the Fukushima-Daiichi nuclear plant, Japan’s Ministry of Economy, Trade and Industry (METI) has confirmed.
The ministry’s Nuclear and Industrial Safety Agency (NISA) has released details of short-term emergency safety measures to be implemented at the country’s nuclear power plants, in addition to further medium- to long-term measures.
NISA spokesman Yasuhiro Sakuma told NucNet that METI has asked plant operators to implement six measures including the provision of back-up generators for “emergency situations”.
Other measures include: checking equipment for emergency situations such as tsunamis; preparing an emergency procedure plan; checking plant cooling systems, and checking cooling systems at spent nuclear fuel pools.
The new safety measures do not yet apply to the Fukushima-Daiichi and Fukushima-Daini nuclear plants, NISA said.
METI said the required standard of safety would be aimed at the prevention of reactor core and spent fuel damage even when alternate-current power sources, seawater cooling function and spent fuel-pool cooling function are lost.
According to a document NISA released to NucNet, operators should have backup power-supply vehicles to help cool reactors and spent-fuel pools, fire engines to supply coolant water, and fire hoses to use water from a freshwater tank or sea water pit.
According to NISA, the measures are already being undertaken by operators with completion expected later this month.
However, the agency said operators had been asked to report back by the end of the month. NISA will then audit the nuclear plants and check that short-term measures have been carried out.
In the medium- to long-term, METI has told nuclear power plants to carry out “drastic measures” by addressing “structural issues” at nuclear power plant buildings.
Operators must take into account an “anticipated tsunami” height at installations, with the tsunami which hit Fukushima-Daiichi on 11 March 2011 used as a reference. According to Tepco that tsunami reached heights of up to 15 metres, exceeding the plant’s design reference value of 5 metres.
NISA is also calling for the construction of sea walls and the fitting of watertight doors. Securing spare air-cooled diesel generators and sea water pump motors is also on the list of requirements.
In the document, the ministry sets out separate tsunami countermeasures for both boiling water reactors and pressurised water reactors. All six units at Fukushima-Daiichi are BWRs.
>>Related reports in the NucNet database (available to subscribers)
Tepco Makes Progress In Bid To Restore External Power (News in Brief No. 77, 23 March 2011)
Japan Update: Work Begins To Remove Contaminated Water (News in Brief No. 82, 27 March 2011)
Removing Contaminated Water Might Take Another Week, NISA Says (World Nuclear Review No. 14, 8 April 2011)
The NucNet database contains more than 15,000 reports published since 1991. To subscribe or ask for any further information email info@worldnuclear.org
