Japan's Nuclear Regulation Authority officially decided Wednesday on the country's new safety requirements for nuclear reactors in an effort to prevent recurrences of disasters that happened at the Fukushima Daiichi plant in 2011.

The new regulations are expected to take effect on July 8, paving the way for nuclear power plant runners to apply for the regulator's safety assessment to resume the work of their suspended reactors, according to local media.

Under the new rules, nuclear power plants will be obliged to put in place specific countermeasures against possible severe accidents like reactor core meltdown or huge tsunami.

The utilities will be also required to equip with filtered venting systems to reduce radioactive substances when gas and stream need to be released to prevent damage to containment vessels.

The plants also have to prepare emergency control rooms to guard reactor operations against terrorism attacks or natural disasters.

In addition, the new requirements asked operators of the plants to make striker assessments of whether geological faults running underneath the utilities are active and make sure that key facilities are designed to withstand the largest tsunami estimated to hit the sites.

Four major utilities, namely Hokkaido Electric Power Co., Kansai Electric Power Co., Shikoku Electric Power Co. and Kyushu Electric Power Co., are likely to file for safety screening for a maximum of 12 reactors at six plants as early as July, reported Japan's Kyodo News.