Japan's Nuclear and Industrial Safety Agency said Sunday that efforts to stem the flow of radioactive water leaking from the troubled No. 2 reactor building of the stricken Fukushima Daiichi nuclear power plant into the Pacific Ocean have as yet been unsuccessful.

Earlier Sunday engineers injected 80 kilograms of a polymer- based powder into pipes leading to a pit connected to the plant's No. 2 reactor's building, where a 20-centimeter crack has been found to be leaking radioactive water.

The polymeric powder is water absorbent and can soak up 50- times its own volume in liquid and was used in conjunction with 60 kilograms of sawdust and three bags of shredded newspaper, the agency said.

But the flow of contaminated water continues to exude from the seafront pit, the agency said, although the rate of leakage has remained the same and the concoction of absorbent materials have not been flushed into the sea, the agency said.

Earlier moves to stem the flow including attempts to encase the cracked pipe in concrete also failed leaving the agency to now wait until Monday until the plant's operator Tokyo Electric Power Co. (TEPCO) can provide new data to check if Sunday's efforts to prevent radioactive substances flowing freely into the ocean have had any effect at all.

On Monday TEPCO will also try to determine the exact route of the radioactive flow by draining colored water from the pit, Deputy Director-General of Japan's Nuclear and Industrial Safety Agency Hidehiko Nishiyama said.

But whilst embattled utility firm TEPCO has said that radioactive iodine-131 more than 10,000 times the legal concentration limit was detected in the water found in the pit, Nishiyama said that no similar leaks had been found in any of the other reactor's pits at the crippled Daiichi facility.

Local, national and international concerns are rife however due to the escalating amount of radioactive substances flowing into the Pacific Ocean and the potential threat this will cause to marine life and the fishing industry.

Earlier Sunday Chief Cabinet Secretary Yukio Edano told a news conference that the government believes that it may take several months until the radiation-leaking power plant is brought under control.

"If we apply methods considered to be normal, I believe that it will be something like that," Japan's top government spokesperson said.

"While it may not be feasible, we have been asking for other possibilities to be explored to shorten that period," Edano said, adding that numerous alternative solutions were being considered in an effort to bring the nation's biggest nuclear crisis since WWII to an end.

Edano also said that some 900 thyroid tests have been conducted on infants in the vicinity of the troubled plant, but none of the tests has as yet shown signs of radiation poisoning.

Separately, special government adviser Goshi Hosono told reporters Sunday that individual time frames will be established to curb radiation leaks into the air, seawater and the ground.

Engineers on Sunday also worked to reconnect pumps to an external power source to provide a steady injection of water coolant into the troubled reactors.

The pumps had previously been powered by the facility's emergency diesel generators.

The No. 2 reactor sustained the worst damage following the March 11 magnitude-9.0 earthquake and ensuing tsunami that damaged the reactor's buildings and knocked out four of the reactor's critical cooling functions causing some of the nuclear fuel rods to partially melt and be exposed to the atmosphere.