Oct 25, 2016 21:51
7 yrs ago
2 viewers *
English term
integral value of the source term
English
Science
Mathematics & Statistics
Some analyses of ocean contamination provide not only the integral value of the source term but its kinetics as well.
Another sentence (integral estimation):
The uncertainty in the direct release source term is generally smaller and most analyses show results in the range from 1 PBq to 5.5 PBq of 137Cs (Table 1.4–8), except for the most conservative integral estimation given by IRSN
More info:
Source term: A source term is a specific type of release characteristic of a reactor family representative of a type of accident, i.e. in general, a mode of containment failure following complete core meltdown.
Another sentence (integral estimation):
The uncertainty in the direct release source term is generally smaller and most analyses show results in the range from 1 PBq to 5.5 PBq of 137Cs (Table 1.4–8), except for the most conservative integral estimation given by IRSN
More info:
Source term: A source term is a specific type of release characteristic of a reactor family representative of a type of accident, i.e. in general, a mode of containment failure following complete core meltdown.
Responses
4 +2 | total (see discussion) | DLyons |
3 +2 | integration value of the radioactive contamination | Port City |
Responses
+2
8 hrs
English term (edited):
integral value
Selected
total (see discussion)
The section is talking about Caesium-137 release from the site - both direct release and subsequent atmospheric and ocean contamination. The term just means the total release (which is indeed the time integral but that's just an overly complex way of putting it).
Peer comment(s):
agree |
Terry Richards
1 hr
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Thanks Terry.
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neutral |
Daryo
: it does sound like "just an overly complex way of putting it" but if they feel the need to put it that way I would leave it that way
9 hrs
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Thanks Daryo. You have a point.
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agree |
Yasutomo Kanazawa
22 hrs
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Thanks Yasutomo.
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4 KudoZ points awarded for this answer.
+2
5 hrs
integration value of the radioactive contamination
This isn't my field at all, but "integral value" is "value of integral" as used in calculus.
TEPCO used the term "integrated value".
http://www.nsra.or.jp/isoe/english/fukushima/contamination02...
TEPCO used the term "integrated value".
http://www.nsra.or.jp/isoe/english/fukushima/contamination02...
Peer comment(s):
agree |
Daryo
11 hrs
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Thank you!
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neutral |
Didier Fourcot
: The reference is correct, however it is about doses, it integrates mSv/h dose rates and get mSv along time, here we are talking of activity
13 hrs
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Thank you for your input.
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agree |
acetran
13 hrs
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Thank you!
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Reference comments
46 mins
Reference:
Definition of source term
Peer comments on this reference comment:
disagree |
acetran
: Since it is the same definition the asker provided with his question. Thanks for pointing out.
18 hrs
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I think it's probably the same definition the asker provided with his question / I THINK it's the same one but I'm not sure. I only wanted to help someone. I'm sorry you don't find the reference helpful and thanks for making that clear :)
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15 hrs
Reference:
Why I should avoid mentioning a mathematical integration:
Let's come back to basics and units of measure: a Becquerel is a complicated name for the reciprocal of a second:
https://en.wikipedia.org/wiki/Becquerel
https://orise.orau.gov/reacts/guide/measure.htm
one Bq is one disintegration per second
so the "integral value" if we integrate the number of Becquerels of a source over time is the total number of disintegrations, ie a dimensionless plain number; we should also specify the timeframe of integration, because the source will likely disintegrate before and after our measurement.
However as the period is 30 years, we may consider for the usual timeframes that the activity of the source is constant, ie a (x Bq source) today still disintegrates x Bq tomorrow or one year from now.
So there is no point in mathematically integrating these Becquerels over time, they will repeat tomorrow and the day after, they just measure a quantity of radioactive material.
So if we see today 1 million Bq flowing through a waterway, then 2 millions tomorrow, we may say that 3 millions have passed, this is the concept of kinetics: amount of radioactivity measured at each time period.
The total "integral" number is the total amount of radioactivity that has been released; it is actually an accumulation over time, but I should avoid the mathematical concept of integration because the radioactivity does not disappear.
Let's compare with a water flow: the integral of a flow measured in liters per second is the total volume that has flown, in liters.
BUT the total radioactivity that has been flowing if the radioactivity is 1000 Bq/l remains x times 1000 Bq/l, not 1000 disintegrations per liter.
The confusing thing is that although Bq is s-1, it is NOT a division by time, like m/s, l/s, this is also the reason whay it is different from Hz, which is also formally s-1: travelling at 1 m/s leaves you 1 m ahead after 1 second, but nothing happens after 1 second looking at a source of 1 Bq: an other disintegration will happen over and over again (in fact it will slowly decay to half of it after 30 years), so the concept of integration is confusing and should be replaced with a total over time.
https://en.wikipedia.org/wiki/Becquerel
https://orise.orau.gov/reacts/guide/measure.htm
one Bq is one disintegration per second
so the "integral value" if we integrate the number of Becquerels of a source over time is the total number of disintegrations, ie a dimensionless plain number; we should also specify the timeframe of integration, because the source will likely disintegrate before and after our measurement.
However as the period is 30 years, we may consider for the usual timeframes that the activity of the source is constant, ie a (x Bq source) today still disintegrates x Bq tomorrow or one year from now.
So there is no point in mathematically integrating these Becquerels over time, they will repeat tomorrow and the day after, they just measure a quantity of radioactive material.
So if we see today 1 million Bq flowing through a waterway, then 2 millions tomorrow, we may say that 3 millions have passed, this is the concept of kinetics: amount of radioactivity measured at each time period.
The total "integral" number is the total amount of radioactivity that has been released; it is actually an accumulation over time, but I should avoid the mathematical concept of integration because the radioactivity does not disappear.
Let's compare with a water flow: the integral of a flow measured in liters per second is the total volume that has flown, in liters.
BUT the total radioactivity that has been flowing if the radioactivity is 1000 Bq/l remains x times 1000 Bq/l, not 1000 disintegrations per liter.
The confusing thing is that although Bq is s-1, it is NOT a division by time, like m/s, l/s, this is also the reason whay it is different from Hz, which is also formally s-1: travelling at 1 m/s leaves you 1 m ahead after 1 second, but nothing happens after 1 second looking at a source of 1 Bq: an other disintegration will happen over and over again (in fact it will slowly decay to half of it after 30 years), so the concept of integration is confusing and should be replaced with a total over time.
Discussion
https://www.oecd-nea.org/nsd/docs/1987/csni87-136.pdf