Nuclear waste

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Nuclear waste may mean spent nuclear fuel, extracted from the nuclear reactors.

Nuclear waste may refer to substances with unstable isotopes, created at manufacturing of the nuclear fuel, or retreatment of the spent nuclear fuel.

Nuclear waste may refer to contamination, released to atmosphere, water and/or soil at the accidents, catastrophes or the criminal uncontrolled management.

In all the three cases, term Nuclear waste refers to some dangerous and usually unwanted substance.

Scale of the disaster


Most of popular news agencies, sites, newspapers mention the problem of nuclear contamination or risks of such a contamination, at least in so-called "popular" form, without numerical estimates and without formulas. In the vulgar interpretation, the problem of the nuclear waste appears as a world-wide disaster. Scale of this «disaster» is discussed in this section.

Usually, the authors, who mention the Nuclear waste, do not imagine even orders of magnitude of the quantities they are writing about; in particular, they they do not provide table of the isotopic content of the nuclear waste. This may indicate some kind of sabotage of personal of the nuclear facilities: they do not estimate even orders of magnitude of amounts of the dangerous substance.

However, there are some exceptions from this general rules. The amount of nuclear waste, produced in Germany, is sedimated [1]

The table of amount of 43 most important unstable isotopes produced in Germany in 2022 is copy pasted here:

Noisotopeamount,t
01U-2333.59e-5
02U-2344.50e-1
03U-2358.41e+1
04U-2364.21e+1
05U-2374.79e-7
06U-2389.58e+3
07Pu-2383.05e+0
08Pu-2397.10e+0
09Pu-2403.66e+1
10Pu-2419.91e+0
11Pu-2421.01e+1
12Pu-2449.92e-4
13Th-2293.12e-9
14Th-2301.30e-5
15Th-2321.98e-5
16Pa-2311.33e-6
17Pa-2332.11e-7
18Np-2376.21e+0
19Np-2384.77e-9
20Np-2392.02e-6
21Am-2411.22e+1
22Am-2423.30e-7
23Am-242m2.77e-2
24Am-2432.34e+0
25Cm-2421.16e-3
26Cm-2437.34e-3
27Cm-2445.72e-1
28Cm-2457.43e-2
29Cm-2466.76e-3
30Cm-2479.52e-5
31Cm-2486.56e-6
32Bk-2495.84e-10
33Cf-2499.78e-8
34Cf-2507.51e-9
35Cf-2515.90e-9
36Cf-2525.53e-11
37Cs-1348.74e-2
38Cs-1355.43e+0
39Cs-1371.04e+1
40Sr-904.29e+0
41Tc-999.28e+0
42I-1292.27e+0
43Ru-1063.33e-2

The table above appeared in year 2013; so, one can guess, that it is one a prediction. Up to date, in the open access, no publication is found to confirm or to reject this estimate. However, one can expect, that since year 2013, the nuclear physics had nor chance, nor the main decision of the nuclear reactors; so, at least orders of macnitude of the quantities suggested may be correct.

Main components

The table indicates that the main components of the nuclear waste are

00isotopeamount,tHalflife
03U-2358.41e+1
04U-2364.21e+1
06U-2389.58e+3
07Pu-2383.05e+0
08Pu-2397.10e+0
09Pu-2403.66e+1
10Pu-2419.91e+0
11Pu-2421.01e+1
18Np-2376.21e+0
21Am-2411.22e+1
24Am-2432.34e+0
38Cs-1355.43e+0
39Cs-1371.04e+1
40Sr-904.29e+0
41Tc-999.28e+0
42I-1292.27e+0

At leas one tonne of each of these isotopes is produced yearly in Germany. Extrapolating, one can guess, that the total amount of the isotopes, produced world-wide during a century, is at least 3 orders of magnitude bigger.

The total amount of these nuclear waste is not so big; it could git a cube of size of order of 20 meters. However, it is would not be a good idea to keep all the nuclear waste in a single compact cube; at least because father relaxation heat.

Namely these isotopes should be taken into account in the estimates of the future of the nuclear energetics, at least in century 21. total amount of the isotopes, produced worldwide during a century shold be at least 3 orders of magnitude larger, than in the table above.

Below, the table above is extended: From Wikipedia (mainly), the masses and lifetimes of the contaminants are loaded:

 0	name	M,tonn	atomic m, amu	HalfL,y	En,MeV
 1	U-235	  84	235.04392949	703.8e6 4.9
 2	U-236	  42	236.045568	2.342e7	4.572
 3	U-238	9580	238.05078826	4468.e6	51.77
 4	Pu-238	   3	238.049553	87.7	5.593
 5	Pu-239	   7	239.0521634	24110
 6	Pu-240	  37	240.0538135 	6561
 7	Pu-241	  10	241.057  	14		
 8	Pu-242	  10	242.059  	375000
 9	Np-237	   6	237.0481734	2.144e6
10	Am-241	  12	241.056829144	432.2
11	Am-243	   2	243.0613811	7370
12	Cs-135	   5	134.9059770	2.3e6
13	Cs-137	  10	136.9070895	30.1671
14	Sr-90	   4	89.907738	28.90
15	Tc-99	   9	98.906254	211000
16	I-129	   2	128.904984	1.57е7	0.189

Trash of useful product?

There is no absolute trash. Existence of any "unwanted" substance indicates, that yet, there is no technology, that would make the separation of the substance to components (that has positive price at the market) is economical non-profitable. In many cases, it is cheaper just to store the waste, than to separate it to components that can be sold.

Am-241

The most important (id let, most dangerous) in the table above seem to be Pu-241 and Am-241.

Estimates, that after a 100 years, namely Am-241 will produce the most of the relaxation heat

Art

Warning

References

  1. https://www.hindawi.com/journals/stni/2013/293792/ Research Article | Open Access Volume 2013 |Article ID 293792 | https://doi.org/10.1155/2013/293792 A. Schwenk-Ferrero, "German Spent Nuclear Fuel Legacy: Characteristics and High-Level Waste Management Issues", Science and Technology of Nuclear Installations, vol. 2013, Article ID 293792, 11 pages, 2013. https://doi.org/10.1155/2013/293792

https://pubs.rsc.org/en/content/articlelanding/2022/ja/d2ja00052k Aurélien Beaumais, ORCID logo *a Anthony Nonell,*a Céline Caussignac,a Sébastien Mialle,a Guillaume Stadelmann,b Myriam Janin,c Hélène Isnard,a Michel Aubert,a Thomas Vercouterd and Frédéric Chartiere. Journal of Analytical Atomic Spectrometry. Issue 6, 2022. he low abundance cerium-144 radionuclide is one of the significant contributors to the decay heat from spent nuclear fuel for cooling times of less than ten years after nuclear reactor discharge. The accurate quantification of the 144Ce content (or 144Ce/238U) in irradiated nuclear fuel is necessary to validate and extend the neutronic calculation codes as well as to improve the short-term nuclear waste management strategies. In order to quantify the 144Ce/238U atomic ratios at low uncertainty, we developed a new analytical technique based on double spike isotope dilution associated with mass spectrometry. This includes (1) the chemical elimination of the major neodymium-144 isobaric interference by two steps of liquid chromatography prior to isotope analysis by Thermal Ionization Mass Spectrometry (TIMS) using both total evaporation and sequential methods, and (2) the preparation and use of an in-house double spike solution, using a mixture of a natural Ce solution with a 233U-enriched solution. This new approach was applied for the first time on two Mixed Oxide (MOx) spent nuclear fuel samples and allowed the determination of 144Ce/238U atomic ratios ranging from 35 × 10−6 to 59 × 10−6 with a relative expanded uncertainty of measurement of around 1% at a 95% confidence level.