Fukushima 1 Nuclear Accident Day 18, 19, 20

Monday, 28 March

High levels of radiation from contaminated water hindered work on restoring the cooling pumps and other powered systems to reactors 1-4. The Japanese Nuclear Safety Commission reported that it assumed melted fuel rods in Unit 2 released radioactive substances into cooling water which subsequently leaked out through an unknown route to the Unit 2 turbine building basement.

In hopes of reducing the amount of water leaking, TEPCO reduced the amount of water pumped into Reactor 2 from 16 tons per hour to 7 tons per hour, despite the priority of cooling the reactor core. Confirming concerns, the temperature in the reactor raised by 20°C. Highly radioactive water was also found in three "trenches" (tunnels that house electrical wires from the turbines) which stretch toward, but do not connect to, the sea. Water levels in trenches of Units 2 and 3 were 1m below the level at which they would overflow to the sea, while the Unit 1 trench was 10cm from overflowing. TEPCO reported they used sandbags and concrete to prevent an overflow at the opening of the tunnel.

TEPCO confirmed finding low levels of plutonium in five samples from 21 March and 22 March, concluding that "two samples out of five may be the direct result of the recent incident."

Tuesday, 29 March

Unit 1 water injection is transfered from fire engine pumping to an emergency pump. Unit 4 control room power is restored, the final control room to receive power. Unit 2 and 3 water injection changes from salt water to freshwater. Radiation reaches the United Kingdom, with very low levels of radioactive iodine detected in Glasgow and Oxfordshire, although there is no evidence that this iodine is from Japan.

Wednesday, 30 March

Smoke escaped from the Fukushima II (Dai-ini) nuclear plant. Fukushima II plant is 6 miles from the Fukushima I (Dai-Ichi) facility, and was thought not to be at risk.

At Fukushima I, Japan's Nuclear and Industrial Safety Agency (JNISA) reiterated concerns about a unit 3 breach on 30 March. NHK World reported the JNISA's concerns as "air may be leaking," very probably through "weakened valves, pipes and openings under the reactors where the control rods are inserted," but that "there is no indication of large cracks or holes in the reactor vessels." Plans were announced to spray debris at the Fukushima plant with a water-soluble resin to prevent further spread of radioactivity. The concentration of 131
I in seawater, 330 m south of the discharge canal of units 1 to 4 at 13:55, March 29th, 2011, was 130,000 Bq/l or 3,355 times the regulatory limit (the highest so far). The concentration of 134
Cs was 520 times the regulatory limit, while 137
Cs was 350 times the limit.

Nuclide	Concentration (Bq/cm3)	Regulatory limit (Bq/cm3)	Concentration / Regulatory Limit
99m Tc	1.6×10−1	4.0×101	.04
131 I	1.3×102	4.0×10−2	3250
134 Cs	3.1×101	6.0×10−2	517
136 Cs	2.8×100	3.0×10−1	9.3
137 Cs	3.2×101	9.0×10−2	356
140 Ba	5.0×100	3.0×10−1	17
140 La	2.5×100	4.0×10−1	6.3

In Primorsky Krai, Russia, the Head of the Maritime Administration on Hydrometeorology and Environmental Monitoring reported trace amounts of radioactive iodine-131 detected in air samples taken from 26 March to 29 March.

Fukushima 1 Nuclear Accident Day 15, 16, 17

Friday, 25 March

Units 1, 2 and 3 had possible breaches in their containment vessels. NISA announced that a breach had likely occurred in the containment vessel of the unit 3 reactor, the only one using a plutonium fuel mix (MOX). Officials suspected it was leaking radiation. Kyodo News reported highly radioactive water was found in the turbine buildings of unit 1 and 2.

US Navy began the transport by barge of 1,890 cubic meters (500,000 gallons) of fresh cooling water to the Fukushima reactors. This fresh water supply is expected to arrive on site within two days.

Japan announced transportation would be provided in a voluntary evacuation zone of 30 kilometres (19 mi).

Tap water was reported to be safe for infants in Tokyo and Chiba but still exceeded limits in Hitachi and Tokaimura.

An analysis of stagnant water in the basement floor of the turbine building of Unit 1 showed heavy contamination.

Nuclide	Concentration (Bq/ml)
38 Cl	1.6×106
74 As	3.9×102
91 Y	5.2×104
131 I	2.1×105
134 Cs	1.6×105
136 Cs	1.7×104
137 Cs	1.8×106
140 La	3.4×102

Saturday, 26 March

Replacing seawater with fresh water for cooling became a priority due to worries that the salt in the seawater was clogging pipes and coating fuel rods, which may have been hindering the cooling process.

It was reported that radiation levels in water in the unit 2 turbine room measured 1 Sv/h, or 10 million times the normal radioactivity of water circulating in an operating reactor, and four times the yearly level allowed for workers. This has since been denied by Japanese officials as a misread by one of the employees working inside the plant, prompting all of the workers to flee before a second reading could be taken to confirm.

Sunday, 27 March

The IAEA announced that workers hospitalized for treatment of radiation burns on Friday had been exposed to between 2 and 6 Sv of radiation at their ankles when standing in water in unit 3.

TEPCO reported measurements of very high radiation levels of 1000 mSv/hr in the basement of the unit 2 turbine building, which officials reported was 10 million times higher than what would be found in the water of a normally functioning reactor. Hours into the media frenzy, the company retracted its report and stated that the figures were not credible. "because the level was so high the worker taking the reading had to evacuate before confirming it with a second reading." Shortly following the ensuing wave of media retractions that discredited the report worldwide, TEPCO clarified its initial retraction; the radiation from the pool surface in the basement of the unit 2 turbine building was found to be "more than 1,000 millisieverts per hour," as originally reported, but the concentration of radioactive substances was only 100,000 times higher than usual, not 10 million. The high radiation levels delayed technicians working to restore the water cooling systems for the troubled reactors.

Japan's Nuclear and Industrial Safety Agency indicated that "The level of radiation is greater than 1,000 millisieverts. It is certain that it comes from atomic fission. But we are not sure how it came from the reactor."

The IAEA reported temperatures at the bottom of the Reactor Pressure Vessel (RPV) at Unit 2 fell to 97 °C from 100 °C on Saturday. Water is being pumped from the turbine hall basement to the condenser in order to allow power restoration activities to continue.

New aerial video recorded on 27 March by a Ground Self-Defense Force helicopter revealed the clearest and most detailed view of the damaged plant to date. Significant observations included:

• White vapor, possibly steam, emanating from the buildings of reactors 2, 3, and 4.
• The roof of the reactor 2 building has been badly damaged but is still intact.
• The reactor 3 building is largely uncovered, its roof blown off in a hydrogen explosion over two weeks prior.
• The walls of the reactor 4 building have also collapsed.

Fukushima 1 Nuclear Accident Day 14: Thursday, 24 March

12:10

Three workers were exposed to radiation amounting to 170 to 180 millisievert in the underground of No. 3 reactor's turbine building, and two of them were hospitalized due to possible radiation burns to their legs.

Fukushima 1 Nuclear Accident Day 13: Wednesday, 23 March

00:34

The BBC reported that external power cables were connected to all units at Fukushima I nuclear power plant and lighting was back on again in the control room of unit 3.

10:15

MSNBC reports that at some point over the prior 24 hour period, "emergency crews dumped 18 tons of seawater into nearly boiling storage pool holding spent nuclear fuel at Unit 2, cooling it to 105 °F (41 °C)".

19:00

Reported I-131 plume across Pacific ocean and USA. Data collected by CTBTO and reported by ZAMG.

21:00

TEPCO status report

Status of Fukushima I at 21:00 on 23 March

	Unit 1	Unit 2	Unit 3	Unit 4	Unit 5	Unit 6
Power output (MWe)	460	784	784	784	784	1100
Type of reactor	BWR-3	BWR-4	BWR-4	BWR-4	BWR-4	BWR-5
Status at earthquake	In service -> shutdown	In service -> shutdown	In service -> shutdown	Outage	Outage	Outage
Core and Fuel Integrity (Loaded fuel assemblies & mass estimation)	Damaged (400 ≈ 83 t UO2 singly)	Damaged (548 ≈ 114 t UO2)	Damaged (548 ≈ 106 t UO2 8 t PuO2)	No fuel rods	Not damaged (548 ≈ 114 t UO2)	Not damaged (764 ≈ 148 t UO2)
Pressure vessel integrity	Unknown	Unknown	Unknown	Not damaged	Not damaged	Not damaged
Containment integrity	Not damaged	Damage suspected	Might be ”Not damaged”	Not damaged	Not damaged	Not damaged
Core cooling system 1 (ECCS/RHR)	Not functional	Not functional	Not functional	Not necessary	Functional	Functional
Core cooling system 2 (RCIC/MUWC)	Not functional	Not functional	Not functional	Not necessary	Functioning (in cold shutdown)	Functioning (in cold shutdown)
Building integrity	Severely damaged	Slightly damaged	Severely damaged	Severely damaged	Vent hole opened on rooftop to prevent hydrogen explosion	Vent hole opened on rooftop to prevent hydrogen explosion
Reactor pressure vessel, water level	Fuel exposed	Fuel exposed	Fuel exposed	Safe	Safe	Safe
Reactor pressure vessel, pressure	Stable	Unknown	Unknown	Safe	Safe	Safe
Containment pressure	Stable	Stable	Decreasing after Mar. 20th increase	Safe	Safe	Safe
Seawater injection into core	Continuing	Continuing	Continuing	Not necessary	Not necessary	Not necessary
Seawater injection into containment building	(confirming)	To be decided	(confirming)	Not necessary	Not necessary	Not necessary
Containment venting	Temporarily stopped	Temporarily stopped	Temporarily stopped	Not necessary	Not necessary	Not necessary
Integrity of fuel in Spent Fuel Pool (Stored spent fuel assemblies & mass estimation)	Unknown (292 ≈ 60 t)	Unknown (587 ≈ 122 t)	Possibly damaged (514 ≈ 106 t)	Possibly damaged (1331 ≈ 312 t)	Not Damaged (946 ≈ 196 t)	Not Damaged (876 ≈ 182 t)
Cooling of the Spent Fuel Pool (SFP)	Water injection to be considered	Seawater Injection conducted on Mar. 20th	Water level low, Water injection continuing, effectiveness has been confirmed	Water level low, Water injection continuing, Hydrogen from SFP exploded	Pool cooling capability was recovered	Pool cooling capability was recovered
Main Control Room Habitability & Operability	Poor due to loss of AC power	Poor due to loss of AC power	Poor due to loss of AC power (Lighting has been recovered)	Poor due to loss of AC power (Lighting has been recovered)	Not damaged (estimate)	Not damaged (estimate)
Environmental effect (NPS border)	The Main Gate: 265.4 µSv/h at 15:00, Mar. 23. Radioactive nuclides exceeding the legal standard were detected in milk produced in Fukushima and Ibaraki prefectures and spinach and some other vegetables produced in Fukushima, Ibaraki and other prefectures. Also, radioactive Iodine exceeding the standard set by Nuclear Safety Commission was detected in tap water in Fukushima prefecture. The level of the radioactivity detected is low enough not to do harm to the health of people who take those products or water for a limited time. Monitoring results of seawater sampled at coasts in the surrounding area of the station showed that radioactive Iodine, I-131, and Cesium, Cs-134, 137, exceeding the regulatory limit were detected.
Evacuation radius	20 km from Nuclear Power Station (NPS). People who live between 20 km to 30 km from the Fukushima I Nuclear Power Station are to stay indoors.
INES (estimated by NISA)	Level 5	Level 5	Level 5	Level 3	-	-
Remarks	Immediate threat is damage of the fuels in the fuel pool outside the containment vessel. The operation for spraying water to the pool is continuing at Unit 3 and 4. Work to recover AC power for Unit 1 through 6 is in progress. External AC power has reached to Unit 2, 4, 5 and 6 and is now available in all the units. Integrity check of electric equipment is going on in each unit, which must be done before energizing them. Lighting has been recovered at Unit 3 Main Control Room. External AC power has replaced with the emergency diesel generator in Unit 5 and 6.

Fukushima 1 Nuclear Accident Day 12: Tuesday, 22 March 2011

2:32

TEPCO has issued a statement that a 0.5 litre sample of sea water 'in the vicinity of the outlet of the plant' has revealed an iodine-131 increase of 126.7 times 'above standard levels.', among increases of other isotopes.

10:00

TEPCO status released for 10:00.

Fukushima 1 Nuclear Accident Day 11: Monday, 21 March 2011

15:55

Grey smoke emitted from the southeast corner of the Reactor Building #3 at the Fukushima I (Daiichi) plant, in the area of the spent fuel pool. TEPCO evacuated the site temporarily.

19:00

White smoke emitted from the roof of Reactor Building #2 at the Fukushima I (Daiichi) plant.

20:00

Full scale cooling restored for the Reactor #5.

23:45

Investigators and researchers in Japan criticized the lack of data on radioactive releases, making it difficult to predict the path of dispersal.

Fukushima 1 Nuclear Accident Day 10: Sunday, 20 March 2011

03:00

Restored emergency power to the spent fuel pond cooling systems for units 5 and 6 have brought the unit 5 pond temperature down from 68.8 °C to 43.1 °C and the unit 6 pond temperature down from 67.5 °C to 52 °C as of 03:00 JST.

04:26

"The Nuclear and Industrial Safety Agency said there is some positive progress and engineers at the end may not need to open valves inside the container vessel of the No. 3 reactor to alleviate pressure that is building up", while they were initially planning this action. Such a move, if forced, would release more radioactive steam.

09:00

Spent fuel pond water temperature dropped to 36.1 °C at Unit 5 and 36.6 °C at Unit 6.

16:00

Status of Fukushima I at 16:00 on 20 March

	Unit 1	Unit 2	Unit 3	Unit 4	Unit 5	Unit 6
Power output (MWe)	460	784	784	784	784	1100
Type of reactor	BWR-3	BWR-4	BWR-4	BWR-4	BWR-4	BWR-5
Status at earthquake	In service -> shutdown	In service -> shutdown	In service -> shutdown	Defueled	Outage	Outage
Fuel integrity	70% damaged	33% damaged	Damaged	No fuel rods	Not damaged	Not damaged
Pressure vessel integrity	Unknown	Unknown	Unknown	Not damaged	Not damaged	Not damaged
Containment integrity	Not damaged	Damage suspected	Unknown	Not damaged	Not damaged	Not damaged
Core cooling system 1 (ECCS/RHR)	Not functional	Not functional	Not functional	Not necessary	Not necessary	Not necessary
Core cooling system 2 (RCIC/MUWC)	Not functional	Not functional	Not functional	Not necessary	Not necessary	Not necessary
Building integrity	Severely damaged	Slightly damaged	Severely damaged	Severely damaged	Vent hole opened on rooftop to prevent hydrogen explosion	Vent hole opened on rooftop to prevent hydrogen explosion
Pressure vessel, water level	Fuel exposed	Fuel exposed	Fuel exposed	Safe	Safe	Safe
Pressure vessel, pressure	Stable	Unknown	Stable	Safe	Safe	Safe
Containment pressure	Unknown	Low	Stable at higher level after increase	Safe	Safe	Safe
Seawater injection into core	Continuing	Continuing	Continuing	Not necessary	Not necessary	Not necessary
Seawater injection into containment building	Continuing	To be decided	Continuing	Not necessary	Not necessary	Not necessary
Containment venting	Temporarily stopped	Temporarily stopped	Temporarily stopped	Not necessary	Not necessary	Not necessary
Integrity of fuel in Spent Fuel Pool (SFP)	Water injection to be considered	(no data)	SFP level low, Water injection continues	SFP level low, Water injection started, Hydrogen from SFP exploded	Pool cooling capability was recovered	Pool cooling capability was recovered
Environmental effect (NPS border)	At 05:40, March 20: 269.5 µSv/hour (West Gate); and 3054 µSv/hour to the North of the Service Building (at 15:00, March 20)
Evacuation radius	20 km from Nuclear Power Station (NPS). People who live between 20 km to 30 km from the Fukushima I Nuclear Power Station are to stay indoors.
INES	Units 1-3, Level 5 (estimated by Japanese NISA and accepted by the international IAEA); Level 6 (estimated by the French Nuclear Safety Authority, ASN); Unit 4, Level 3.

Fukushima 1 Nuclear Accident Day 9: Saturday, 19 March 2011

00:45

Water dousing resumes on Unit 3 by hyper rescue troop with the cooperation of Tokyo Fire Department. Finished at 01:10.

12:50

Power line is connected to power plant but not activated yet.

19:07

Milk and spinach from areas around power plant have been found with radiation level exceed Japan's standards. Japan government halt sales of all food from Fukushima prefecture.

Status of Fukushima I at 10:00 on 19 March

	Unit 1	Unit 2	Unit 3	Unit 4	Unit 5	Unit 6
Power output (MWe)	460	784	784	784	784	1100
Type of reactor	BWR-3	BWR-4	BWR-4	BWR-4	BWR-4	BWR-5
Status at earthquake	In service -> shutdown	In service -> shutdown	In service -> shutdown	Defueled	Outage	Outage
Fuel integrity	70% damaged	33% damaged	Damaged	No fuel rods	Not damaged	Not damaged
Pressure vessel integrity	Unknown	Unknown	Unknown	Not damaged	Not damaged	Not damaged
Containment integrity	Not damaged	Damage suspected	Might not be damaged	Not damaged	Not damaged	Not damaged
Core cooling system 1 (ECCS/RHR)	Not functional	Not functional	Not functional	Not necessary	Not necessary	Not necessary
Core cooling system 2 (RCIC/MUWC)	Not functional	Not functional	Not functional	Not necessary	Not necessary	Not necessary
Building integrity	Severely damaged	Slightly damaged	Severely damaged	Severely damaged	Vent hole opened on rooftop to prevent hydrogen explosion	Vent hole opened on rooftop to prevent hydrogen explosion
Pressure vessel, water level	Fuel exposed	Fuel exposed	Fuel exposed	Safe	Safe	Safe
Pressure vessel, pressure	Stable	Unknown	Stable	Safe	Safe	Safe
Containment pressure	Unknown	Low	Low	Safe	Safe	Safe
Seawater injection into core	Continuing	Continuing	Continuing	Not necessary	Not necessary	Not necessary
Seawater injection into containment building	Continuing	To be decided	Continuing	Not necessary	Not necessary	Not necessary
Containment venting	Temporarily stopped	Temporarily stopped	Temporarily stopped	Not necessary	Not necessary	Not necessary
Integrity of fuel in Spent Fuel Pool (SFP)	Water injection to be considered	(no data)	SFP level low, Water injection continues	SFP level low, Preparing water injection, Hydrogen from SFP exploded	SFP temperature increasing	SFP temperature increasing
Environmental effect (NPS border)	304 µSv/hour at 3:30, 19 March
Evacuation radius	20 km from Nuclear Power Station (NPS). People who live between 20 km to 30 km from the Fukushima I Nuclear Power Station are to stay indoors.
INES	Units 1-3, Level 5 (estimated by Japanese NISA and accepted by the international IAEA); Level 6 (estimated by the French Nuclear Safety Authority, ASN); Unit 4, Level 3

22:21

Radioactive iodine in trace amounts have been found in tap water in Tokyo and 5 other areas near Fukushima; and caesium-137 trace amounts have been found in Tochigi and Gunma prefectures. The Japanese government says the amounts did not exceed safety limits and should not affect human health.

23:52

Radioactive iodine beyond limit detected in tap water in a town in Fukushima, reports Kyodo News with reference to government.

Fukushima 1 Nuclear Accident Day 8: Friday, 18 March

01:55

Engineers have begun laying power grid cabling to unit 2. Power to unit 2 will be reconnected once the spraying of water on the unit 3 reactor building ceases.

03:00

The IAEA announce the termperature at the spent fuel pond at reactor 5 is 65.5 °C and the temperature of the spent fuel pond at reactor 6 is 62.0 °C a slight decrease since yeterday at reactor 6 and a slight increase since yesterday at reactor 5

04:33

BBC reports with reference to UN's nuclear watchdog that reactor 2 is connected to power line. It may allow operators to restart Emergency Core Cooling System and Residual Heat Removal pumps for the reactor.

05:30

TEPCO reports that laying of grid cabling to Unit 2 continues. The United States military is using unmanned aerial vehicles to view the reactor.

11:00

The United States is sending water pumps to Japan.

14:00

Water dousing resumes on unit 3 by the Japan Self-Defense Forces (SDF), rotating with the Tokyo Fire Department (TFD), which is also managing unit 1.

16:00

Status of Fukushima I at 16:00 March 18

	Unit 1	Unit 2	Unit 3	Unit 4	Unit 5	Unit 6
Power output (MWe)	460	784	784	784	784	1100
Type of reactor	BWR-3	BWR-4	BWR-4	BWR-4	BWR-4	BWR-5
Status at earthquake	In service	In service	In service	Defueled	Outage (scheduled)	Outage (scheduled)
Fuel integrity	70% damaged	33% damaged	Damaged	No fuel rods	Not damaged	Not damaged
Containment integrity	Not damaged	Damage suspected	Might not be damaged	Not damaged	Not damaged	Not damaged
Core cooling system 1 (ECCS/RHR)	Not functional	Not functional	Not functional	Not necessary	Not necessary	Not necessary
Core cooling system 2 (RCIC/MUWC)	Not functional	Not functional	Not functional	Not necessary	Not necessary	Not necessary
Building integrity	Severely damaged	Slightly damaged	Severely damaged	Severely damaged	Not damaged	Not damaged
Pressure vessel, water level	Fuel exposed	Fuel exposed	Fuel exposed	Safe	Safe	Safe
Pressure vessel, pressure	Stable	Unknown	Stable	Safe	Safe	Safe
Containment pressure	Unknown	Low	Low	Safe	Safe	Safe
Seawater injection into core	Continuing	Continuing	Continuing	Not necessary	Not necessary	Not necessary
Seawater injection into containment building	Continuing	To be decided	Continuing	Not necessary	Not necessary	Not necessary
Containment venting	Temporarily stopped	Temporarily stopped	Temporarily stopped	Not necessary	Not necessary	Not necessary
Integrity of fuel in Spent Fuel Pool (SFP)	Water injection to be considered	(no data)	SFP level low, Water injection continue	SFP level low, Preparing water injection, Hydrogen from SFP exposed	SFP temperature increasing, 65.5 °C	SFP temperature decreasing, 62.0 °C
Environmental effect (NPS border)	271 µSv/hour at 7:30 p.m., March 18
Evacuation radius	20 km from Nuclear Power Station (NPS). People who live between 20 km to 30 km from the Fukushima I Nuclear Power Station are to stay indoors.
INES	Level 5 (estimated by Japanese NISA and accepted by the international IAEA); Level 6 (estimated by the French Nuclear Safety Authority, ASN and the Finnish nuclear authorities)

18:40

IAEA raises INES level from 4 to 5. Radiation reading 1km from reactor #2 - 292.2 µSv/hour

22:00

A plume model shows that the movement of the radioactive material is primarily across the ocean.

Fukushima 1 Nuclear Accident Day 7: Thursday, 17 March

01:37

The Australian Department of Foreign Affairs and Trade issued a Travel Advice Bulletin advising Australian travellers to reconsider the need to travel to Tokyo, the surrounding earthquake-affected districts, Chiba, Fukushima, Aomori, Iwate, Nagano, Niigata and Ibaraki prefectures and not to travel to the Fukushima Nuclear Power Plant exclusion zone and Miyagi Prefecture.

03:50

IAEA Director announces he will travel to Japan to "see the situation for himself".

04:00

The US Embassy, on advice from the Nuclear Regulatory Commission, told Americans to evacuate a radius of "approximately 50 miles (80 km)" from the Fukushima plant.

05:25 (approximately)

The head of the U.S. Nuclear Regulatory Commission, Gregory Jaczko, said that the fuel pool at unit 4 had run dry and as a result, radiation levels at the plant were "extremely high". TEPCO denied that the pool had run dry and said "the condition is stable" at unit 4.

09:00

Radiation levels in cities near Fukushima I plant: 13.9 µSv at Fukushima City, 65 km northwest; 2.71 µSv at Kooriyama city, 60 km west; 1.25 µSv at Iwaki city, 40 km southwest.

09:19 (approximate)

Naoki Tsunoda, a TEPCO spokesman, indicates that the new power lines to the plant were almost finished and that officials planned to try it "as soon as possible." Kyodo said that could be as early as Thursday afternoon.

09:48

Japan's Self Defense Force used CH-47 helicopters to perform water spraying operations on reactor unit 3. JAIF reported that the helicopter had been specially modified with lead shielding to protect the personnel onboard. However, much of the water appeared to be dispersed in the wind before reaching its target.

10:00

Helicopter based spraying operations were halted after 4 water drops were performed on unit 3. Japanese newscaster NHK indicated that spraying operations will continue from the ground and that personnel are monitoring the radiation levels around the base.

10:15

The IAEA releases a summary of all injuries and contaminations due to the situation at the Fukushima I nuclear plant. It indicates that 23 people were injured, more than 20 were contaminated, and 2 are missing.

10:40

JAIF reports that the radiation levels at the main gate are 10 millisieverts per hour.

11:05

The Japanese nuclear safety agency says external power to the plant should partially resume later in the day.[Kyodo News]

11:10

Radiation reading at the Fukushima I Nuclear Power Station (NPS) border is 646 µSv/hour.

12:00

The IAEA announce that the temperature in spent fuel pond at reactor 5 is 64.2 °C and the spent fuel pond at reactor 6 is 62.5 °C

12:07

Cabinet Secretary Edano says Unit 3 is the top priority for cooling efforts [Kyodo News]

16:00

The Japan Times reports that radiation levels at the main gate drop to 1.5 millisieverts per hour. Additionally, after hours of conflicting reports on the cause of the white smoke emitting from unit 3, Chief Cabinet Secretary Yukio Edano corrects an earlier statement and now believes that the smoke is being relased from the storage pool at unit 3, and not the containment vessel.

16:00

Status of Fukushima I at 16:00 March 17

	Unit 1	Unit 2	Unit 3	Unit 4	Unit 5	Unit 6
Power output (MWe)	460	784	784	784	784	1100
Type of reactor	BWR-3	BWR-4	BWR-4	BWR-4	BWR-4	BWR-5
Status at earthquake	In service	In service	In service	Defueled	Outage (scheduled)	Outage (scheduled)
Fuel integrity	70% damaged	33% damaged	Damaged	No fuel rods	Not damaged	Not damaged
Containment integrity	Not damaged	Damage suspected	Damage suspected, but considered to be unlikely.	Not damaged	Not damaged	Not damaged
Core cooling system 1 (ECCS/RHR)	Not functional	Not functional	Not functional	Not necessary	Not necessary	Not necessary
Core cooling system 2 (RCIC/MUWC)	Not functional	Not functional	Not functional	Not necessary	Not necessary	Not necessary
Building integrity	Severely damaged	Slightly damaged	Severely damaged	Severely damaged	Not damaged	Not damaged
Pressure vessel, water level	Around half of the fuel	Higher than half of the fuel	Around half of the fuel	Safe	Safe	Safe
Pressure vessel, pressure	Stable	Unknown	Stable	Safe	Safe	Safe
Containment pressure	Stable	D/W: Unknown, S/P: Atmosphere	Stable	Safe	Safe	Safe
Seawater injection into core	Continuing	Continuing	Continuing	Not necessary	Not necessary	Not necessary
Seawater injection into containment building	Continuing	To be decided	Continuing	Not necessary	Not necessary	Not necessary
Containment venting	Continuing	Preparing	Continuing	Not necessary	Not necessary	Not necessary
Integrity of fuel in Spent Fuel Pool (SFP)	(no data)	(no data)	SFP level low, Preparing water injection	SFP level low, Preparing water injection, Damage to fuel rods suspected	SFP temperature increasing	SFP temperature increasing
Environmental effect (NPS border)	646 µSv/hour at 11:10, March 17
Evacuation radius	20 km from Nuclear Power Station (NPS). People who live between 20 km to 30 km from the Fukushima I Nuclear Power Station are to stay indoors.
INES	Level 4 (estimated by Japanese NISA and accepted by the international IAEA); Level 6 (estimated by the French Nuclear Safety Authority, ASN and the Finnish nuclear authorities)

17:00

South Korean foreign minister Kim Sung-hwan urged South Koreans in Japan to stay 80 kilometers outside the earthquake-stricken nuclear complex in Fukushima.

17:30

Rewiring unit 2 to the Japanese power grid was completed at 08:30 UTC and IAEA indicates that Power will be turned on once the spraying of unit 3 is completed.

19:25

Workers begin spraying water from "special pumper trucks" similar to those used for aircraft fires onto unit 3.

22:00

Status of Fukushima I at 22:00 March 17

	Unit 1	Unit 2	Unit 3	Unit 4	Unit 5	Unit 6
Power output (MWe)	460	784	784	784	784	1100
Type of reactor	BWR-3	BWR-4	BWR-4	BWR-4	BWR-4	BWR-5
Status at earthquake	In service	In service	In service	Defueled	Outage (scheduled)	Outage (scheduled)
Fuel integrity	70% damaged	33% damaged	Damaged	No fuel rods	Not damaged	Not damaged
Containment integrity	Not damaged	Damage suspected	Damage suspected, but considered to be unlikely.	Not damaged	Not damaged	Not damaged
Core cooling system 1 (ECCS/RHR)	Not functional	Not functional	Not functional	Not necessary	Not necessary	Not necessary
Core cooling system 2 (RCIC/MUWC)	Not functional	Not functional	Not functional	Not necessary	Not necessary	Not necessary
Building integrity	Severely damaged	Slightly damaged	Severely damaged	Severely damaged	Not damaged	Not damaged
Pressure vessel, water level	Around half of the fuel	Higher than half of the fuel	Around half of the fuel	Safe	Safe	Safe
Pressure vessel, pressure	Stable	Unknown	Stable	Safe	Safe	Safe
Containment pressure	Unknown	D/W: Unknown, S/P: Atmosphere	Stable	Safe	Safe	Safe
Seawater injection into core	Continuing	Continuing	Continuing	Not necessary	Not necessary	Not necessary
Seawater injection into containment building	Continuing	To be decided	Continuing	Not necessary	Not necessary	Not necessary
Containment venting	Continuing	Preparing	Continuing	Not necessary	Not necessary	Not necessary
Integrity of fuel in Spent Fuel Pool (SFP)	(no data)	(no data)	SFP level low, Starting water injection	SFP level low, Preparing water injection, Damage to fuel rods suspected	SFP temperature increasing, 64.2 °C	SFP temperature increasing, 62.5 °C
Environmental effect (NPS border)	309 µSv/hour at 15:30, March 17
Evacuation radius	20 km from Nuclear Power Station (NPS). People who live between 20 km to 30 km from the Fukushima I Nuclear Power Station are to stay indoors.
INES	Level 4 (estimated by Japanese NISA and accepted by the international IAEA); Level 6 (estimated by the French Nuclear Safety Authority, ASN and the Finnish nuclear authorities)

20:09

Workers finish successfully spraying 30 tons of water from pumper trucks onto Unit 3, and TEPCO is now evaluating the effectiveness of the operation. IAEA indicates that the spraying of water on the Unit 3 reactor building was temporarily stopped.

22:37

Reuters reports that work has started to connect outside power lines to the Fukishima I nuclear power plant. Unit 2 will be the first to receive electricity. The earliest this could happen is Friday.