Nuclear Fusion Plant Force Cycle Nuclear Fusion Plant Clip Art

1. Introduction

The study of different technologies to achieve complete control of nuclear fusion reactions has led to the construction of systems that are at present widely used in scientific research. Sometimes these systems employ fusion reactions for straight applications, every bit is the instance of neutron generators, but more frequently they implement technologies useful for the evolution of time to come nuclear fusion reactors.

The plasma systems based on the magnetic confinement of ionized gases, such as the "plasma focus" and the "tokamak", belong to the latter group, too equally the auxiliary systems of future reactors such every bit the "neutral beam injectors". All the systems mentioned above produce ionizing radiations, which are e'er fabricated upward of neutron beams, accompanied by photon beams. When the energies and the intensities of neutrons take the minimum necessary characteristics, activation is produced with balance radioactivity during and at the end of the operation.

Although the radioactive decay generated in these cases is not of the order of the one due to the operation of nuclear fission plants, radionuclides produced or deposited in solids, liquids, and aeriforms due to the functioning of nuclear fusion devices are not e'er negligible and represent a concern for the correct management of radioactive waste and the control of releases into the environment.

The current report considers the different radiation fields and radioactive materials that are produced at the facilities based on nuclear fusion reactions. The associated risks and safety management are considered and discussed with the aim of describing the radiation protection arroyo and the consistent depression bear on on workers and population.

2. Radiation Fields and Radioactive Materials of Concern

Radiation emitted past devices that use nuclear fusion reactions are generally very similar and often have comparable characteristics. In most cases, these systems are based on deuterium-deuterium (D-D) and/or deuterium-tritium (D-T) reactions, according to the following main reactions:

Neutron production is apparent in both cases. These fast neutrons have high initial energy, about fourteen MeV in the D-T reaction, and about 2.4 MeV in the D-D reaction.

In D-D systems there is a production of tritium due to the concurrent reaction:

The absenteeism of an free energy threshold for these reactions implies that a loftier acceleration of deuterium towards the target is non necessary. Typically, some hundreds of keV are sufficient to let the crossing of the Coulomb barrier and to brand effective the reaction that is always exothermic. The radioactive rest and the consistent contamination are essentially due to the action of the neutron fields that activate the materials determining the germination of different radionuclides in the structures of the machines themselves and in the surrounding surround, including atmospheric air.

Table 1 shows the principal gamma emitters due to the activation of solid metallic materials, which compose the structures of the machines, following the interaction with high energy neutrons. The evaluation was carried out for the International Thermonuclear Experimental Reactor (ITER) experimental nuclear fusion plant (the international experiment on tokamak magnetic confinement fusion, currently under structure in Cadarache, France) in the design phases [1].

In summary, the sources of ionizing radiation in devices based on nuclear fusion reactions are those listed beneath:

• primary neutron field resulting from D-D and D-T fusion reactions;

• prompt gamma radiations emitted in subsequent interactions;

• delayed gamma radiation emitted by activated products;

• activated dust contagion;

• activated corrosion products generated in h2o and liquid metal refrigeration systems;

• activation of cooling h2o;

• air activation;

• tritium used every bit a fuel for the fusion reaction, or produced in the D-D reaction;

• residues containing tritium and gamma emitters.

3. Systems Based on Fusion Reactions

In this context, the term "nuclear fusion systems" refers to machines that are sometimes commercial simply mainly experimental. Commercial devices are essentially the so-called "neutron generators" that are used in enquiry, logistics, security, healthcare, and industry. The neutron generators use the fusion reactions described above, mainly the D-T one due to the more favorable conditions of reaction. The D-T reaction has past far the largest reactivity even at "depression" energies, of the order of hundreds of keV, as shown by the graph in Figure ane, which compares the D-T reaction reactivity with other fusion reactions [2]. D-T reactivity is maximum at about T = 64 keV and for plasma temperature below 60 keV is at least 10 times larger than the reactivity of any other reaction.

The D-T reaction requires the lowest working temperature and has the highest reaction cross-section and reactivity (boilerplate number of reactions per unit time and density) at the temperatures achievable in the laboratory. Therefore, this reaction has been chosen in the most common applications. It is an exothermic reaction that releases 17.6 MeV in the form of kinetic energy of the resulting products (14.ane MeV for the neutron, three.5 MeV for the alpha particle).

Neutrons produced by this reaction tin can be used in different ways, even taking advantage of the firmness of some generators that can be of the portable blazon. The main uses of commercial neutron generators are in geological surveys, replacing sealed neutron sources (AmBe, AmB, and ²⁵²Cf), and in neutron activation assay of materials subject to control for safety or inspection reasons. These generators are based on the D-T reaction, so they comprise a certain amount of tritium, mainly between 100 and 200 GBq for a production of the order of 10⁸ neutrons per second.

Among the experimental machines, in addition to developing neutron generators, we must mention the experimental facilities for the report of nuclear fusion technology, with the aim of creating actual nuclear fusion reactors to produce electricity. Amidst the latter the systems currently most adult in Italian republic are those using magnetic confinement in toroidal geometry (Tokamak). The divertor tokamak test (DTT) facility under construction in Frascati (RM) is one of these Tokamaks.

Among the support studies for the realization of time to come fusion reactors, the neutral beam injectors (NBI) are accelerators in which the acceleration of deuterium involves the presence of D-D and D-T reactions, with the resulting production of neutrons and the potential activation of the surrounding materials. Currently, all major tokamak-type nuclear fusion experiments use NBI for plasma heating.

4. The DTT Facility and the Tokamaks

I of the chief challenges in the European programme in view of the construction of a Demonstration nuclear fusion power establish (DEMO) is the trouble of thermal loads onto the divertor (the main component for the disposal of the thermal power of the plasma in a fusion power plant). ITER has been planned to test the real potential of a "conventional" divertor working with the plasma completely "detached" from the wall. Unfortunately, this solution could not be exploitable in the operating conditions of DEMO and future reactors. Therefore, the problem of thermal loads on the divertor could remain peculiarly critical in the road towards the realization of the bodily reactor.

For these reasons, a specific program was launched to design a tokamak called divertor tokamak test (DTT). This device volition acquit out scale experiments in guild to look for alternatives of the divertor fully uniform with the specific physical conditions and technological solutions provided in DEMO. DTT must allow experimenting with different magnetic configurations, with components based on the apply of liquid metals and other solutions suitable for the problem of rut loads onto the divertor.

In a future perspective, controlled thermonuclear fusion can provide energy, without some problems of environmental bear upon of current nuclear fission ability plants, and therefore free energy produced in this manner will exist:

• low ecology impact: the products of the most promising fusion reaction (D-T) are just helium and neutrons. Radioactive waste is non produced and with a right selection of materials, radioactivity induced in the structural components decays in a relatively brusk fourth dimension.

• intrinsically safe: chain reactions are not possible as at that place is but a very limited quantity of reagents in the vacuum chamber; in case of harm, accidents, or loss of control, the fusion reaction with consequent generation of heat will decay very apace and automatically shut off.

• sustainable: deuterium and lithium (tritium is actually produced in the reactor through interaction with lithium) are widespread and practically inexhaustible in nature (deuterium is nowadays in large quantities in sea h2o and lithium can be extracted both from rocks and from oceans).

A tokamak-type nuclear fusion device has a construction of the kind shown in Figure 2 with an external container called cryostat, which has the role of thermally insulating the interior. The internal vacuum chamber has a principal toroidal geometry from which some conduits branch out; at the end of them there are some doors that let access to the interior, where there are the first wall, formed past various steel tiles, and the cassettes of the divertor, also metal, which tin be either in the lower part or in the upper part of the vacuum chamber.

five. Emissions in the Air

The activation of the air surrounding a device based on nuclear fusion reactions, following the interaction with the neutrons that are produced, involves the production of some radionuclides, among which the main ones are: ³H, ^xiC, ¹³Northward, ^xviN, ^xivO, ¹⁵O, ³⁷Due south, ³⁷Ar, ⁴¹Ar, ³⁹Cl, and ⁴⁰Cl. Those who by and large contribute the most to the dose and need to be considered for the evaluation of releases in the environs are: ¹⁵O (for a 30%), ¹¹C, ^thirteenN, ⁴¹Ar (over 50%), ³⁹Cl and ^twoscoreCl.

More often than not, the reaction that determines the need to size the ventilation arrangement and that requires the demonstration of respect for the impact on the population is the ⁴⁰Ar (n, gamma) ⁴¹Ar [3].

The activation of air in these plants does not usually affect operational scenarios equally releases in the environment are responsible for very low doses and below the exposure constraints for the population both in the case of normal activity and as a result of accidental releases.

half dozen. Activation of Solids

In the case of machines that apply fusion reactions, solids are activated, too considering of high-energy neutrons, which decide the production of radionuclides that are partly different from those ordinarily produced past lower-energy neutrons. In order to assess the contribution to the activation of the diverse parts, one must consider the materials that make upwardly the main structures of the machines, which are substantially steel (SS304L, SS316LN and, for future reactors, low-iron-to-ferritic steels euro-FER) and copper alloys (mainly CuCrZr). As an example, Table 2 shows a possible composition of these materials, which is not strictly defined but can vary from fourth dimension to time in some components depending on the manufacturers.

The SS304L steel is the 1 used in normal applications to build technological structures, also in part of the machines for fusion reactions.

When exposed to intense neutron fluxes, SS304L is activated and gives ascent to the production of several radionuclides. By ways of software bachelor on the web, it is possible to notice the radionuclides produced in this type of steel by low-free energy neutrons, and by fast neutrons. In Table 3, a partial result is reported for the offset case. Atomic number 26-55, Cr-51, some isotopes of Ni, Co-60, Mo-99, and Nb-94 can be noticed in the list and are almost the same radionuclides previously encountered in Table 1.

In devices already built or being designed in recent times, in view of the loftier neutron flows present, low-activation steels have been used reducing, in particular the content of Ni, Co, Nb, and Mo. The so-called "EUROFER" is actually one of these steels. A calculation similar to that of Table 3 applied to EUROFER provides the results of Tabular array 4.

The decrease in radioactive inventory is evident as the reduction of the presence of components such as nickel, cobalt, molybdenum, and niobium results in an important decrease in radionuclide activation. Figures in the tables refer to zero cooling times. If we consider longer times or the gild of the twelvemonth, EUROFER is fifty-fifty more than advantageous as radionuclides with higher T_1/two are the ones that derive by nickel, niobium, and cobalt, which are present in low quantities in this type of steel.

An example of the radioactive inventory that can be found in operating plants is shown in Tabular array 5 and Tabular array 6 from a study conducted for the NBI device [4], where D-D reactions occur, developed in Italy, and then used for ITER. Figures refer to different waiting times afterward the shutdown and the lower number of surviving radionuclides can be easily noticed in the second instance. The radioactive elements are really the same equally those shown in Table three and Table 4, which are of a general nature. In some cases, information technology may exist useful to refer to the integral result that indicates total radioactive decay following activation. Figure 3 indicates the theoretical issue [5] obtained with calculation codes related to the activation of the parts inside the vessel of DTT, where neutrons from D-D reactions dominate. The graphs shown refer to different phases of the machine's functioning, indicating the integral activity for the components, depending on the cooling time after the stop of the action. For example, it may exist noted that at the stop of the DTT operations it takes several tens of years to reach radioactivity concentrations of less than 1 Bq/g. Otherwise, some components removed during the working life of the machine autumn beneath the aforementioned concentration in a few months.

7. Activation in the Refrigeration Circuits

In the refrigeration circuits mainly used in fusion-based systems, the coolant is usually h2o and the pipes are made of metal materials (usually steels or copper alloys). In these circuits, activation can take place both in the h2o itself and in the walls of the pipes that are corroded and eroded by water, leading to dispersion of activated corrosion products (ACPs) in the cooling loops. Water activation occurs because of the interaction of fast neutrons with ¹⁷O and ¹⁶O to form ¹⁷North and ^sixteenN, respectively, which emit high-energy gamma rays. These two n,p-blazon reactions have threshold reactions of near ten MeV of energy for incident neutrons and therefore occur only as a result of DT reactions, so they are peculiar of this type of device (and are, for example, negligible in nuclear fission reactors). Another specific issue is the subsequent decay of the ¹⁷N, which emits loftier-energy delayed neutrons (0.383 and 1.171 MeV), which in turn tin activate the materials. ACPs that disperse in the refrigerant are composed of the aforementioned radionuclides already considered in the activation of the solids.

eight. Issues Related to the Presence of Tritium

ITER and future devices (east.g., DEMO) will apply hydrogen isotopes deuterium and tritium to fuel the fusion reaction. While deuterium is a widely bachelor and well-nigh inexhaustible resource (information technology can exist distilled from all forms of water), tritium is a fast-decaying radioelement of hydrogen, which occurs only in trace quantities in nature. As a consequence, tritium for a fusion reactor must be produced on site, direct in the reactor "breeding" blanket. The fuel cycle of a fusion reactor consists of all the operations dedicated to the extraction and purification of the tritium from the breeding coating, equally well as the handling of the gaseous and liquid streams containing the hydrogen isotopes [6]. With the realization of a "airtight" fuel cycle, the tritium is bars to the fusion power plant in such a style that it can fulfil the requirement of safe production of clean energy.

In a fusion reactor, about of the systems processing the fusion fuels volition be hosted in a defended tritium constitute (TP). Here, the different isotopes can be isolated by detritiation of gas streams, so that deuterium and tritium can over again be fueled into the reactor. ITER will take a 35 m alpine × 80 m long × 25 one thousand broad TP building. These dimensions are necessary to house the systems responsible for tritium recovery, isotope separation, deuterium-tritium fuel storage, and delivery. However, it should exist noted that ITER will merely test modest mock-ups of tritium breeding elements, with an estimated daily production less than 0.4 g. In contrast, the European DEMO, designed to demonstrate tritium cocky-sufficiency at a reactor scale, may reach a production as high as 250 g/24-hour interval.

For the above-mentioned reasons, tritium is present in small or large corporeality in all the parts of tokamak plants. Tritium has a high solubility and diffusivity, from which derives a high permeability to tritium of most materials, such as polymers, metals subject field to hydride formation, metals unsuitable for hydride formation, silica, ceramics, and graphite. Tritium too diffuses through glass, peculiarly at loftier temperatures. Therefore, in the cases in which the tritium is used as fuel, the issue of tritium retention in the materials of the walls may arise due to the interaction betwixt the plasma and the wall itself. Thus, it is necessary to provide for the disposal of tritiated targets and tritium-containing residues.

Regarding human exposure, tritium emits beta radiation of maximum energy of 18.half-dozen keV and a range less than 6 mm in air, which practise not penetrate neither the dead layer of the skin, nor the wearing apparel or gloves. For the purpose of radiation protection, the critical aspect is therefore the tritium intake, the internal contamination and the committed effective dose.

In ITER the amount of tritium that will be handled is in the order of 10¹⁷ Bq (i.e., a few kg) [7]. In the analysis of blow scenarios, the full amount of tritium is a key chemical element. In particular, tritium can be found:

• in the vacuum vessel, as united nations-burnt fuel.

• in the cooling loops of the plasma facing components (PFC) and vacuum vessel, due to gas permeation in the pipes.

• in the temper of the buildings

• in the outer atmosphere, post-obit an accidental release

• in the tritium arrangement.

The tritium build-up in the vacuum vessel is not considered a concern, both for workers and for the population [viii]. Previous research demonstrated that the acute release of 10 GBq of tritium accumulated in the vacuum vessel of the ITER neutral beam injector produces a dose to the population below ane μSv/year (i.e., about three order of magnitude lower than the regulatory dose limit for population) [9].

In the case b), tritium is mixed with other source terms like activated corrosion products (ACPs) and dusts when released. As a consequence, the general consensus is that it does not represent a major concern.

As a general dominion, the containment of tritium is designed to reduce as much as possible the contamination of the building surfaces and temper (case c)). However, diffusion and outgassing of tritium from materials may produce tritium release in the atmosphere of the edifice. It is generally assumed that the ventilation systems should keep the airborne tritium level below the monitoring devices detection level [5]. When the dose rate due to tritium concentration in air exceeds approximately 25 µSv/h, the personnel will evacuate or wear protective equipment. Every bit a upshot of these precautions, the doses resulting from tritium exposure should be very express (<ane% of objective) [ten].

Regarding the accidental release of tritium outside the facility (case d), past inquiry demonstrated that the maximum dose to the population in the worst-case scenario is well within the regulatory dose limits [11]. The tritium maximum dose received at 2.v km distance from the site (closest firm to the bespeak of release) is expected not to exceed 0.3 mSv, due to the accidental release of i g of HTO. A like dose value (0.4 mSv) was found by Nie et al. [12]. When chronic ingestion is considered, the dose to the population would exist about 2.ane mSv following the accidental release of 1 g of HTO [12].

In the analysis of emergency scenarios, accidents in tritium treatment and in the fueling system (case e)) stand for a critical consequence. A detailed assay of possible accidents is discussed elsewhere [8] and will not be repeated hither. Meaning information on the influence of tritium on the worker dose come from the (Joint European Torus) JET experience developed in the flow 1997–2002 when an boilerplate collective worker dose of 37 person-mSv was estimated [eight].

Finally, it is worth mentioning tritium reservoir in portable generators. As a affair of fact, tabletop neutron generators have evolved from a big, expensive instrument to a compact, affordable production. Minor neutron generators using the deuterium (²H)-tritium (ⁱⁱⁱH) reaction are the virtually common accelerator-based neutron sources. Creating deuterium ions and accelerating these ions into a tritium or deuterium target produces neutrons. Deuterium atoms in the beam fuse with deuterium and tritium atoms in the target to produce neutrons. However, previous research has demonstrated that releases from portable generators do non correspond a concern form a radiation protection point of view [13].

nine. Types of Waste: Clearance and/or Release Routes

From what has been explained to a higher place, radioactive materials potentially released past plants making use of DD or DT reactions may not have T_one/2 < 75 days and cannot therefore exist considered "exempt" pursuant to art 154 of Legislative Decree 230/95 and subsequent amendments. According to the Ministerial Decree of seven August 2015, the classification of the radioactive waste in Italy at present complies with the IAEA General Safety Guide No. GSG-1, following the full general scheme shown in Effigy 4. Actually, Italian regulation refers to the activity and non to the "level" of the radioactive waste, as clarified in Figure 4. In this classification procedure besides the release constraints defined in the European guide RP 122 [14] are considered.

Solid nuclear waste ordinarily comes from the removal and replacement of components and the release of dispensable protective wearable used in maintenance operations. Maintenance during functioning involves the production of nuclear waste, peculiarly in large machines such as loftier-power tokamaks (e.g., DTT and ITER) or examination systems for NBI, for example the i developed in Italian republic for ITER. In tokamaks it is indeed very common to replace the tiles of the get-go wall and the divertor cassettes with remote treatment systems to avoid undue exposure of operators. Every bit highlighted above, for these parts within the vacuum chamber the radioactive inventory is pregnant.

Normally, neutron generators exercise not produce radioactive waste during their operations, except in the case of replacement of the tritiated target (frequent in big, non-portable generators). Yet, the exhausted targets are normally withdrawn by companies that supply the new ones.

10. Discussion and Last Remarks

The above analysis shows that virtually of the devices based on nuclear fusion reactions currently on the market do non present disquisitional points regarding the production of nuclear waste or residues. Neutron generators have characteristics and technological solutions such equally to exclude almost completely the product of radioactive waste during performance, autonomously from the tritiated targets of some generators which are withdrawn by the suppliers themselves and then disposed of equally radioactive waste. The situation changes when we consider the experimental machines for nuclear fusion currently in operation and to a higher place all those under structure.

In these cases, high neutron fluxes, often college than 10^xv due north south⁻¹, determine the activation of the internal components closer to the plasma in which fusion reactions take identify. These components accomplish concentrations of radioactivity which, in instance of maintenance and replacement, brand difficult the hands-on operations and correspond a nuclear waste to be disposed of according to the laws in force, although in many cases they are made with selected metals with low activation. Pursuant to the Ministerial Decree of seven Baronial 2015, they are essentially waste of "very depression" or "low" activity, while radioactive waste with "medium" or "loftier" activity is never produced, dissimilar the case of nuclear fission reactors.

Fifty-fifty the liquid and gaseous releases into the surround deriving from the functioning of the fusion plants practice not present critical issues from the betoken of view of radioactivity and the consequent impact on the exposure of the population, although the content of these effluents must exist the object of accurate analysis and checks every bit both air and water of cooling circuits take radioactivity concentrations which, especially in the case of water, tin require the need to release them as radioactive waste product.

In summary, it tin be stated that in all cases the right choice of materials and the adoption of acceptable procedures allow simplified management of all types of radioactive release and waste, which can be contained in the low-level or very low-level categories, pursuant to the laws.

Author Contributions

Information curation, R.V.; Formal analysis, M.D.; Resources, M.D., M.K. (Maurizio Guarracino), C.P. and R.V.; Software, 1000.G. (Maurizio Guarracino) and R.5.; Supervision, S.South.; Validation, S.S.; Writing—original draft, S.S.; Writing—review & editing, K.M.C. and M.G. (Manuela Guardati). All authors have read and agreed to the published version of the manuscript.

Funding

This enquiry received no external funding.

Conflicts of Interest

The authors declare no conflict of interest.

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Effigy 1. Reactivity averaged over a Maxwell–Boltzmann distribution as a part of plasma temperature, from [two].

Figure 1. Reactivity averaged over a Maxwell–Boltzmann distribution as a role of plasma temperature, from [2].

Effigy 2. 3D cantankerous section of divertor tokamak exam (DTT).

Figure two. 3D cantankerous department of divertor tokamak test (DTT).

Figure 3. Activating DTT in-vessel components.

Effigy 3. Activating DTT in-vessel components.

Figure 4. Radioactive waste classification as IAEA Full general Safety Guide 1. In square brackets the Italian definition. HLW: high level waste, ILW: intermediate level waste, LLW: low level waste, VLLW: very depression level waste product, VSLW: very brusk lived waste product, EW: exempt waste.

Figure iv. Radioactive waste nomenclature as IAEA General Prophylactic Guide one. In square brackets the Italian definition. HLW: high level waste, ILW: intermediate level waste, LLW: low level waste, VLLW: very low level waste, VSLW: very brusk lived waste, EW: exempt waste.

Table 1. Principal radionuclides due to the activation in solid metallic structures and their main gamma emissions [ane].

Table 1. Main radionuclides due to the activation in solid metallic structures and their main gamma emissions [1].

Nuclide	Half-life (T1/two)	Energy (Probability) keV (%)
54Mn	312 days	834.8 (100)
58Co	70.nine days	511 (29.9)	864 (0.68)	1675 (0.52)	810.8 (99.4)
60Co	5.27 years	1173 (100)	1332 (100)
51Cr	27.7 days	320 (ix.85)
57Ni	36.1 h	127 (sixteen)	1378 (eighty)	1757 (half dozen.i)	1919 (thirteen.9)
56Mn	two.58 h	847 (99)	1810 (27)	2113 (14)
57Co	271.8 days	14 (nine.5)	122 (85.vi)	137 (x.vi)
64Cu	12.7 h	511 (36)	1346 (5)		Copper blend
59Fe	44.six days	192 (3)	1099 (57)	1292 (43)

Tabular array 2. Typical composition of the main metals of current and hereafter employ (EUROFER).

Tabular array two. Typical composition of the main metals of current and future utilize (EUROFER).

Materials	Elements (%)
	Fe	Cr	Ni	C	Si	Mn	P	S	Mo	Co	Zr	Al	Northward	Cu
SS304L	65.71	xix	12	0.03	1	ii	0.03	0.03	0	0.two			0	-
SS304L	64.49	17	12	0.03	ane	2	0.05	0.03	3	0.two			0.2	-
EUROFER	87.23	ix	0.005	0.xi	0.005	0.four	0	0.03	0.005	0.005		0.01	0.2	0.005
CuCrZr	0.i	ane	0	0	0	0	0	0	0	0	0.2	0	0.2	98.five

Table three. Activating i kg of SS304L with slow and thermal neutrons, after turning off the beam.

Table three. Activating i kg of SS304L with ho-hum and thermal neutrons, after turning off the axle.

Element Mass	Activation Reaction
Iron, 660 thou	36.97 m 54Fe(due north,γ)55Fe → 243.iv GBq (2700 y)
Chromium, 190.0 grand	7.94 g 50Cr(n,γ)51Cr → iii.02 TBq (27.seventy d)
Nickel, 120 g	80.87 k 58Ni(n,γ)59Ni → 38.26 MBq (75⋅10iii y)
	4.55 g 62Ni(northward,γ)63Ni → 5.05 GBq (96 y)
	1.9 thousand 64Ni(north,γ)65Ni → 36.five GBq (ii.52 h)
Cobalt, 2 g	two thousand 59Co(due north,γ)sixtyCo → 105.iv GBq (5.27 y)
Manganese, 20 g	20 g 55Mn(n,γ)56Mn → 5.85 TBq (2.57 h)
Molybdenum, 30 grand	4.26 k 92Mo(n, γ)93Mo → 115.ane kBq (3.5⋅10three y)
	93mNb → i.591 kBq (13.6 y)
	vii.39 mg 98Mo(n, γ)99Mo → 12.44 GBq (66 h)
	99mTc → 10.90 GMBq (6.02 h)
	99Tc → 21.70 kBq (213⋅10iii y)
Niobium, 100 mg	100 mg 93Nb(n, γ)94Nb→ 27.85 kBq (20.three⋅10three y)

Table 4. Activation of 1 kg of EUROFER with boring and thermal neutrons, after turning off the beam.

Table 4. Activation of 1 kg of EUROFER with slow and thermal neutrons, later turning off the beam.

Element Mass	Activation Reaction
Atomic number 26, 872.3 thousand	48.86 thou 54Fe(n,γ)55Iron → 321.7 GBq (2700 y)
	2.71 g 58Fe(n,γ)59Atomic number 26 → 70.05 GBq (44.53 d)
Chromium, 90.0 k	3.76 g lCr(north,γ)51Cr → one.430 TBq (27.70 d)
Nickel, 50 mg	33.69 mg 58Ni(n,γ)59Ni → xv.94 kBq (75⋅103 y)
	1.89 mg 62Ni(due north,γ)63Ni → 2.x MBq (96 y)
	495.half dozen μg 64Ni(n,γ)65Ni → 15.20 MBq (2.52 h)
Manganese, 4.0 1000	four.0 one thousand 55Mn(n,γ)56Mn → 1.17 TBq (2.57 h)
Niobium, 10 mg	10 mg 93Nb(n, γ)94Nb → 2.78 kBq (20.3⋅10iii y)
Molybdenum, 50 mg	7.11 mg 92Mo(n, γ)93Mo → 191.eight kBq (iii.5⋅tenthree y)
	93mNb → ii.65 Bq (13.6 y)
	12.31 mg 98Mo(n, γ)99Mo → 20.74 MBq (66 h)
	99mTc → 18.xvi MBq (6.02 h)
	99Tc → 36.xvi Bq (213⋅103 y)
Cobalt, fifty mg	l mg 59Co(north,γ)60Co → 2.63 GBq (5.27 y)
Copper, l mg	34.25 mg 63Cu(n,γ)64Cu → two.96 GBq (12.7 h)
	xv.75 mg 65Co(n,γ)66Cu → 633.5 MBq (5.i 1000)
Aluminium, 100 mg	100 mg 27Al(due north,γ)28Al → ane.03 GBq (2.24 1000)

Table 5. Activation later 10 min cooling time for the Megavolt ITER Injector and Concept Advocacy (MITICA) dump, from D-D reactions.

Table 5. Activation after 10 min cooling fourth dimension for the Megavolt ITER Injector and Concept Advancement (MITICA) dump, from D-D reactions.

Nuclide	Activity (Bq)	% Activeness	Reaction
56Mn	4.93⋅1010	49.26	55Mn(due north,γ)56Mn
58mCo	2.90⋅1010	28.99	58Ni(n,p)58mCo
58Co	6.82⋅109	68.fifteen⋅10−1	58Ni(n,p)58Co 58Ni(northward,p)58mCo → 58Co
51Cr	3.42⋅109	34.17⋅10−1	50Cr(due north,γ)51Cr
99Mo	1.47⋅ten9	14.70⋅10−i	98Mo(due north,γ)99Mo
99mTc	1.20⋅x9	12.03⋅10−1	98Mo(n,γ)99Mo(β−) → 99mTc
101Tc	i.19⋅109	11.93⋅10−ane	100Mo(n,γ)101Mo(β−) → 101Tc
101Mo	9.03⋅108	xc.sixteen⋅10−2	100Mo(n,γ)101Mo
64Cu	eight.19⋅10eight	81.75⋅10−2	63Cu(n,γ) 64Cu
54Mn	6.58⋅x8	65.72⋅x−ii	54Fe(n,p)54Mn
65Ni	2.94⋅x8	29.37⋅10−two	64Ni(due north,γ)65Ni
31Si	1.76⋅108	17.62⋅10−2
66Cu	1.44⋅ten8	xiv.42⋅10−ii	65Ni(due north,γ)66Cu
55Fe	1.29⋅teneight	12.92⋅10−2	54Fe(due north,γ)55Fe
182Ta	1.05⋅108	x.58⋅10−2	181Ta(n,γ)182Ta
55Cr	8.12⋅x7	81.11⋅10−iii	54Cr(n,γ)55Cr
59Fe	6.88⋅107	68.77⋅x−3	58Fe(n,γ)59Fe
92mNb	3.55⋅107	35.44⋅10−three	92Mo(n,p)92mNb
60Co	3.07⋅107	30.68⋅10−3	59Co(north,γ)60Co 59Co(n,γ)60mCo(It) → 60Co

Tabular array 6. Activation after 10 years of cooling time for the Megavolt ITER Injector and Concept Advancement (MITICA) dump, from D-D reactions.

Tabular array 6. Activation after ten years of cooling time for the Megavolt ITER Injector and Concept Advocacy (MITICA) dump, from D-D reactions.

Nuclide	Activity (Bq)	% Activity	Reaction
55Iron	1.03⋅10vii	49.59	54Fe(n,γ)55Fe
60Co	8.27⋅tensix	39.81	59Co(n,γ)60Co 59Co(n,γ)60mCo(IT) → 60Co
63Ni	1.97⋅10half-dozen	94.81⋅10−1	62Ni(due north,γ) 63Ni 63Cu(north,p) 63Ni
54Mn	ii.00⋅105	96.62⋅ten−2	54Iron(n,p)54Mn
59Ni	one.73⋅104	83.21⋅ten−three
fourteenC	5.88⋅x3	28.xxx⋅10−3
93Mo	4.seventy⋅10three	22.64⋅ten−3
3H	iii.34⋅tenthree	16.08⋅10−3
93mNb	1.twoscore⋅x3	67.68⋅10−4
99Tc	3.26⋅ten2	15.68⋅10−iv
94Nb	3.88⋅10−1	18.67⋅10−seven

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