Measurements of permeation rate were carried out under steady-state conditions. The permeability was calculated by assuming that there existed a square-root dependence upon the T pressure. It was further assumed that H and T atoms diffused independently. The pressure dependence of the permeability was determined at 961K, using pressures which ranged 8 x 10-9 to 4 x 10-8Pa. The permeability results could be described by:

P (molT/s m Pa½) = 3.84 x 10-7 exp[-73.7(kJ/mol)/RT]

Tritium Permeability and Pressure Dependence of 304L Stainless Steel in the Temperature Range 723 to 1023K. M.Matsuyama, J.D.Redman: Metallurgical Transactions A, 1983, 14[3], 498-500

 

Table 64

Diffusivity of D in AISI 316

 

Temperature (K)

Pb-Li Layer

D (m2/s)

518

yes

6.8 x 10-13

526

no

2.4 x 10-12

540

no

2.3 x 10-12

547

no

4.6 x 10-12

548

yes

1.7 x 10-12

556

yes

2.0 x 10-12

556

no

3.7 x 10-12

570

yes

1.9 x 10-12

584

yes

2.1 x 10-12

589

yes

3.2 x 10-12

589

no

6.0 x 10-12

600

no

6.8 x 10-12

625

yes

5.7 x 10-12

626

yes

5.0 x 10-12

626

no

9.6 x 10-12

629

yes

4.6 x 10-12

632

no

6.9 x 10-12

652

no

1.0 x 10-11

665

yes

8.5 x 10-12

667

yes

8.5 x 10-12

667

no

1.6 x 10-11

680

no

1.8 x 10-11