News in Brief / Brief No. 70 / 17 March 2011
Damage To Spent Fuel At Units 3 And 4 Is 'Immediate Threat'
17 Mar (NucNet): Japanese authorities have started using helicopters to drop
water onto the spent fuel pools at Fukushima-Daiichi units 3 and 4 in an
effort to counter the "immediate threat" of damage to the fuel, the Japan
Atomic Industrial Forum (JAIF) has said.
In an update at 16:00 Japan time today (08:00 central European time), JAIF
said the helicopter operation had begun at 09:48 Japan time on 17 March.
JAIF also said workers at the plant are preparing to cool the unit 3 and 4
spent fuel pools using high pressure ground pumps.
JAIF said the temperature of fuel in the spent fuels pools at units 5 and
6 is increasing and spent fuel rods in unit 4's fuel pool have probably been
damaged.
There was no information on the condition of spent fuel in the spent fuel
pools at units 1 and 2.
Radiation
At Fukushima-Daiichi on 16 March readings close to the main gate varied from
8,000 microsieverts per hour (microSv/hr) early in the night down to 580
microSv/hr at around 09:30 Japan time. At 12:30 they increased to a peak
value of 10,850 microSv/hr and since then have been falling steadily to
about 350 microSv/hr late evening Japan time.
Readings today (17 March) have varied between about 350 microSv/hr at
midnight and 310 microSv/hr at 11:30. These values do not represent too
serious a problem for people working on the site.
However, there have been hot spots because of local contamination or direct
radiation from damaged installations. Near unit 3, the reading this morning
was still about 3,750 microSv/hr; lower than yesterday, but still too high
for workers to be in the area.
At Fukushima-Daini on 16 March the local dose rate readings at the site
boundary varied about between 18microSv/hr and 112 microSv/hr. Other
readings varied between 16 and 35 microSv/hr;
Today (17 March) readings were lower, varying between 15 and 25 microSv/hr
with a downward trend.
It is believed that these higher than normal readings at Fukushima-Daini are
due to releases from Fukushima-Daiichi, which is 11 kilometres in the north.
Casualties
The International Atomic Energy Agency (IAEA) has released details of
confirmed casualties at Fukushima Daiichi:
- 2 Tokyo Electric Power Company (Tepco) employees have minor injuries;
- 2 subcontractor employees are injured, one with broken legs and one whose
condition is unknown;
- 2 people are missing;
- 2 people were "suddenly taken ill";
- 2 Tepco employees were taken to hospital from the plant's control centre;
- 4 people (2 Tepco and 2 subcontractor employees) sustained minor injuries
on 11 March;
- 11 people (4 Tepco, 3 subcontractor, 4 Japanese civil defence employees)
were injured on 14 March.
The latest JAIF status report (17 March 16:00 Japan time) is online:
www.jaif.or.jp/english/news_
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