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Globs

Original Poster:

13,131 posts

118 months

[news] 
Monday 28th March 2011 quote quote all
This thread is for people pontificating about the performance of the various agencies involved, and who want to discuss the nuclear aspect.

All other non-nuclear discussion should be directed to this thread:
http://www.pistonheads.com/xforums/topic.asp?h=0&a...

To start the latest reactor status from the International Atomic Energy Authority is here:
http://www.iaea.org/newscenter/news/tsunamiupdate0...

IAEA said:
1. Current Situation

The situation at the Fukushima Daiichi plant remains very serious.

The restoration of off-site power continues and lighting is now available in the central control rooms of Units 1, 2 and 3. Also, fresh water is now being injected into the Reactor Pressure Vessels (RPVs) of all three Units.

Radiation measurements in the containment vessels and suppression chambers of Units 1, 2 and 3 continued to decrease. White "smoke" continued to be emitted from Units 1 to 4.

Pressure in the RPV showed a slight increase at Unit 1 and was stable at Units 2 and 3, possibly indicating that there has been no major breach in the pressure vessels.

At Unit 1, the temperature measured at the bottom of the RPV fell slightly to 142 °C. At Unit 2, the temperature at the bottom of the RPV fell to 97 °C from 100 °C reported in the Update provided yesterday. Pumping of water from the turbine hall basement to the condenser is in progress with a view to allowing power restoration activities to continue.

At Unit 3, plans are being made to pump water from the turbine building to the main condenser but the method has not yet been decided. This should reduce the radiation levels in the turbine building and reduce the risk of contamination of workers in the turbine building restoring equipment.

No notable change has been reported in the condition of Unit 4.

Water is still being added to the spent fuel pools of Units 1 to 4 and efforts continue to restore normal cooling functions.

Units 5 and 6 remain in cold shutdown.

We understand that three workers who suffered contamination are still under observation in hospital.

Globs

Original Poster:

13,131 posts

118 months

[news] 
Monday 28th March 2011 quote quote all

hairykrishna

9,807 posts

90 months

[news] 
Monday 28th March 2011 quote quote all
Globs said:
Weeks of reporting and they're still printing stuff like; "The amount of radiation in that water was an astonishing two to six sieverts"

A sievert is a biologically weighted measure of absorbed dose not an amount of radiation. Is that the dose rate from the water per hour? Per minute? Is it too much to ask than journalists spend an hour or two actually reading background before writing a story? Another example in that article is banging on about 'radiation suits' and somehow implying that the workers were massively disadvantaged compared to 'senior people' and that there aren't enough suits to go around. Lead lined 'radiation suits' will be of next to bugger all use. High energy gammas are not significantly attenuated by an amount of lead you can walk around in.

Globs

Original Poster:

13,131 posts

118 months

[news] 
Monday 28th March 2011 quote quote all
Yes, that makes no sense at all!
Tank_slapper gave a good analogy:

If you are standing in the rain:

Becquerels is similar to the amount of rain that is falling.
Grays is how much of the rain hits you.
Sieverts is how wet that rain makes you.

so they should have been only aware of Becquerels in that context - i.e. counts/second.

From http://www.antirad.com/units.htm

units said:
Dosage units:

Gray (Gy) = 1 Joule/kg

Sievert (Sv) = Gray x QF, where QF is a "quality factor" based on the type of particle.
QF for electrons, positrons, and xrays = 1 QF = 3 to 10 for neutrons, protons dependent upon the energy transferred by these heavier particles.

QF = 20 for alpha particles and fission fragments.

The Sievert is a measure of biological effect.
and

units said:
Converting older units:

1 rad = 1 centigray = 10 milligrays ( 1 rad = 1cGy = 10 mGy )

1 rem = 1 centisievert = 10 millisieverts ( 1 rem = 1cSv = 10 mSv )

1 mrad = 10 uGy

Nominal background radiation absorbed dose of 100 mrad/year = 1 mGy/yr.
Perhaps the journo got the figure from the damage to (2 of) the workers feet, it's still misquoted but if so I understand why he linked it to the water!

MOTORVATOR

3,645 posts

134 months

[news] 
Monday 28th March 2011 quote quote all
You're asking a lot there Hairy for Journos to understand context before opening their mouths, we cant even get it right here. smile

Wasn't there a report early on that the Yanks had to provide 100 suits to the government which seemed a bit odd at the time. With the amount of plants in Japan it seems inconceivable that they didn't have enough of what they needed?

The other thing we have not successfully answered under the noise of how well the plant did given it's been hit by an earthquake is what energy actually hit the plant.

I'll go find the link but the plants were not designed for a particular earthquake size but rather an accelerative energy immediately under the plant which someone decided equalled 8.2. Obviously the energy dissipates the further away the epicentre so do we actually know if it was hit by something exceeding it's design?
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Globs

Original Poster:

13,131 posts

118 months

[news] 
Monday 28th March 2011 quote quote all
MOTORVATOR said:
The other thing we have not successfully answered under the noise of how well the plant did given it's been hit by an earthquake is what energy actually hit the plant.

I'll go find the link but the plants were not designed for a particular earthquake size but rather an accelerative energy immediately under the plant which someone decided equalled 8.2. Obviously the energy dissipates the further away the epicentre so do we actually know if it was hit by something exceeding it's design?
Also the length of the quake at 5 minutes was quite stunning, I can imagine pipes having a bad time with that persistent shaking. I have not seen any word from TEPCO or the IAEA that the plant actually survived the shaking - many just assume it did. For instance what caused the damage in Reactor 4?

I'll keep looking!

eldar

8,533 posts

83 months

[news] 
Monday 28th March 2011 quote quote all
http://www.bbc.co.uk/news/world-12860842

Puts some of the numbers into perspective.

Globs

Original Poster:

13,131 posts

118 months

[news] 
Monday 28th March 2011 quote quote all
More info from the IAEA

http://www.iaea.org/newscenter/news/tsunamiupdate0...

IAEA_28thMar said:
Overall at the Fukushima Daiichi plant, the situation is still very serious.

NISA informed the IEC that a meeting is planned with TEPCO to determine the origin and path of water in the turbine buildings of Units 1 to 4. As seen with the contaminated workers, high dose rates in the turbine buildings and contaminated water in the basements can hamper recovery efforts.

The pumping of contaminated water from the basement floor of Unit 1's turbine building into its main condenser is in progress, whereas at Unit 2 that process has not begun because the steam condenser is full. At Unit 3, the pumping of contaminated water and in particular where it is going, are under consideration. The issue is also being examined for Unit 4.

Temperatures measured at the feed water nozzle and at the bottom of the Reactor Pressure Vessel (RPV) continue to decrease slightly at Units 1 and 2, except the temperature at the feed water nozzle of Unit 1's RPV, which has slightly increased to 274 °C.

A positive development is that the pumping of fresh water into the reactor pressure vessel of Unit 1 is to switch from the use of fire trucks to temporary electrical pumps running on offsite power on 29 March. At Unit 2, this switch was carried out on 27 March, with a diesel generator as backup in case offsite power is interrupted. Fresh water is also being injected continuously into the reactor pressure vessel of Unit 3, albeit currently pumped by fire trucks. The switch to temporary electrical pumps for this unit is planned for today.

On 27 March at Unit 3, water was sprayed into the spent fuel pool using a concrete pump truck, and seawater was also pumped in through the spent fuel cooling system. It is planned to start pumping fresh water into the spent fuel pool tomorrow.

It is also planned to commence pumping freshwater into the spent fuel pool of Unit 4 from tomorrow.
So it looks like still no/little instrumentation, a leak in #3 and #1 heating up (274°C sounds a bit hot for water..)

V88Dicky

5,264 posts

70 months

[news] 
Monday 28th March 2011 quote quote all
Whatever happened to Roentgens?

Globs

Original Poster:

13,131 posts

118 months

[news] 
Monday 28th March 2011 quote quote all
Good question!

According to Answers.com:
answers said:
Roentgens are units of radiation exposure used for x-rays and gamma rays. They are defined in terms of the number of ions produced in one cubic centimeter of air by the radiation.

Improve Answer

Read more: http://wiki.answers.com/Q/What_are_roentgens#ixzz1...
So like Grays for air perhaps.
Maybe here the issue of gamma is not as big as alpha/beta radiation?

Mattt

15,687 posts

105 months

[news] 
Monday 28th March 2011 quote quote all
V88Dicky said:
Whatever happened to Roentgens?
Not an SI unit.

Condieboy

311 posts

65 months

[news] 
Monday 28th March 2011 quote quote all
Globs said:
So it looks like still no/little instrumentation, a leak in #3 and #1 heating up (274°C sounds a bit hot for water..)
Not when it's pressurised as it is, and although there seems to have been a partial meltdown of the core it seems the cooling circuit has remained intact, minimising the escape of fission products.

Globs

Original Poster:

13,131 posts

118 months

[news] 
Monday 28th March 2011 quote quote all
Condieboy said:
Globs said:
So it looks like still no/little instrumentation, a leak in #3 and #1 heating up (274°C sounds a bit hot for water..)
Not when it's pressurised as it is, and although there seems to have been a partial meltdown of the core it seems the cooling circuit has remained intact, minimising the escape of fission products.
Yes I missed that, #1 is pressurised, #2 and #3 are at atmospheric pressure (http://www.iaea.org/newscenter/news/2011/fukushima260311.html).

On the 26th "The temperature measured at the bottom of the RPV is stable at 144 °C", today they say "the temperature at the feed water nozzle of Unit 1's RPV, which has slightly increased to 274 °C" so these are looking at different areas in the reactor.

So #1 seems to be intact like you say.

Globs

Original Poster:

13,131 posts

118 months

[news] 
Tuesday 29th March 2011 quote quote all
Japan Confirms Plutonium in Soil Samples at Fukushima Daiichi.

IAEA said:
After taking soil samples at the Fukushima Daiichi nuclear power plant, Japanese authorities today confirmed finding traces of plutonium that most likely resulted from the nuclear accident there. The Nuclear and Industrial Safety Agency told the IAEA that the Tokyo Electric Power Company (TEPCO) had found concentrations of plutonium in two of five soil samples.
It's all a bit vague as to where these samples were taken, but I guess it's from reactor #3.

A bit of scaremongering going on: http://dcbureau.org/201103281314/Bulldog-Blog/plut... but it does seem that the integrity of the MOX fuel has been compromised, and the RPV is fractured/compromised badly enough for it to get out.

Fume troll

4,383 posts

99 months

Globs

Original Poster:

13,131 posts

118 months

[news] 
Tuesday 29th March 2011 quote quote all
Fume troll said:
TheRegister said:
Here's a roundup of the latest facts
Given that article is dated the 25th, whereas the International Energy Authorities website is updates more than once a day I guess I'll go with the IAEA as my source wink

I also have a tiny suspicion that the IAEA may have more knowledge of nuclear reactors than a publication staffed by people more used to upgrading Windows XP...

If you want even closer information I'd suggest NISA, their press releases can be found on this page: http://www.nisa.meti.go.jp/english/index.html, or more specifically about the soil samples here: http://www.nisa.meti.go.jp/english/files/en2011032... which includes a link to the TEPCO site.

Still, I'm sure if I have a serious NAT routing issue TheRegister would be the place to look.


Globs

Original Poster:

13,131 posts

118 months

[news] 
Tuesday 29th March 2011 quote quote all
BTW TheRegisters figures are at odds with those of the IAEA:

TheRegister said:
(25th March) First up, three technicians working to restore electrical power in the plant's No 3 reactor building stood in some water while doing so. Their personal dosimetry equipment later showed that they had sustained radiation doses up to 170 millisievert. Under normal rules when dealing with nuclear powerplant incidents, workers at the site are permitted to sustain up to 250 millisievert before being withdrawn. If necessary, this can be extended to 500 millisievert according to World Health Organisation guidance.

None of this involves significant health hazards: actual radiation sickness is not normally seen until a dose of 1,000 millisievert and is not common until 2,000. Additional cancer risk is tiny: huge numbers of people must be subjected to such doses in order to see any measurable health consequences. In decades to come, future investigators will almost certainly be unable to attribute any cases of cancer to service at Fukushima.
IAEA said:
(28th March) At noon today in Japan, the three workers mentioned in previous briefings were released from the National Institute of Radiological Sciences where they had been kept under observation. The result of analyses performed indicates that the level of localised exposure received by two of them is between 2,000 and 3,000 millisievert (i.e. somewhat lower than the previous estimate of 2,000 to 6,000 millisievert).
So TheRegister assumes 170mSv, 3 days later it turns out to be between 2000mSv - 6000mSv.

I assume IT guys think dosimeters are worn in people's socks. I hope the workers concerned recover.

hairykrishna

9,807 posts

90 months

[news] 
Tuesday 29th March 2011 quote quote all
Globs said:
So TheRegister assumes 170mSv, 3 days later it turns out to be between 2000mSv - 6000mSv.

I assume IT guys think dosimeters are worn in people's socks. I hope the workers concerned recover.
I imagine that the order of magnitude difference is due to the difference between 'whole body dose' and the dose to their ankles/feet. It is my guess that they received their extremely high skin dose mainly from beta emitters - this dose will have been deposited in the outer layers of skin, giving them the rad burns. They are very likely to recover completely and were released more or less immediately from hospital.

Fume troll

4,383 posts

99 months

[news] 
Tuesday 29th March 2011 quote quote all
Globs said:
Given that article is dated the 25th, whereas the International Energy Authorities website is updates more than once a day I guess I'll go with the IAEA as my source wink

I also have a tiny suspicion that the IAEA may have more knowledge of nuclear reactors than a publication staffed by people more used to upgrading Windows XP...

If you want even closer information I'd suggest NISA, their press releases can be found on this page: http://www.nisa.meti.go.jp/english/index.html, or more specifically about the soil samples here: http://www.nisa.meti.go.jp/english/files/en2011032... which includes a link to the TEPCO site.

Still, I'm sure if I have a serious NAT routing issue TheRegister would be the place to look.

Can't open either of your links. (maybe the winXP upgraders will have some advice on how to post them? wink )

Maybe you could highlight the differences for me?



Cheers,

FT.

Fume troll

4,383 posts

99 months

[news] 
Tuesday 29th March 2011 quote quote all
Globs said:
So TheRegister assumes 170mSv,
The number was from their personal dosemeters...

Globs said:
3 days later it turns out to be between 2000mSv - 6000mSv.
Turns out to be...or estimated by... again, can't open the link so I can't comment further.

Cheers,

FT.
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