176
9 Fuel Retention in a Rector with Full …
As an alternative of bulk W, deposited W on heat sink materials is considered. It
should be mentioned that deposited W layers by surface coating techniques such as
chemical or physical vapor deposition (CVD, PVD), Argon or vacuum plasma spray
(APS, VPS) are porous and H can penetrate deep along connected pours and gran
boundaries to saturate all surface of every grain. Accordingly observed H retention
in them is significantly large compared to commercially available bulk W [22, 23].
Figure 9.10 is a typical example showing how H(T) retained in VPS-W on F-82H
steel after exposure to H plasma or H 2 gas including T [24]. For both cases, T is
uniformly retained in VPS-W, while T penetrated into substrate F-82H by diffusion. Furthermore, exposure to the plasma enhances H penetration by diffusion and
resulted in even permeation in F-82H, suggesting significant increase of T inventory.
Plasma/Gas
Including T
5 mm
φ
Mask
Trium intensity
(b)
(a)
Fig. 9.10 Tritium distribution in depth of VPS-W-coated F-82H steel after exposure to H plasma
or H 2 gas including T at 573 K. a Tritium profile after plasma exposure and b depth profiles after
plasma and gas exposure. The thicknesses of VPS-W and F-82H are 1 mm and 3 mm, respectively
[24]
9 Fuel Retention in a Rector with Full …
As an alternative of bulk W, deposited W on heat sink materials is considered. It
should be mentioned that deposited W layers by surface coating techniques such as
chemical or physical vapor deposition (CVD, PVD), Argon or vacuum plasma spray
(APS, VPS) are porous and H can penetrate deep along connected pours and gran
boundaries to saturate all surface of every grain. Accordingly observed H retention
in them is significantly large compared to commercially available bulk W [22, 23].
Figure 9.10 is a typical example showing how H(T) retained in VPS-W on F-82H
steel after exposure to H plasma or H 2 gas including T [24]. For both cases, T is
uniformly retained in VPS-W, while T penetrated into substrate F-82H by diffusion. Furthermore, exposure to the plasma enhances H penetration by diffusion and
resulted in even permeation in F-82H, suggesting significant increase of T inventory.
Plasma/Gas
Including T
5 mm
φ
Mask
Trium intensity
(b)
(a)
Fig. 9.10 Tritium distribution in depth of VPS-W-coated F-82H steel after exposure to H plasma
or H 2 gas including T at 573 K. a Tritium profile after plasma exposure and b depth profiles after
plasma and gas exposure. The thicknesses of VPS-W and F-82H are 1 mm and 3 mm, respectively
[24]