18.08.2015   NUCLEAR POWER PLANTS

Results from SG11 (2004)

Four powder specimens were delivered from SG11 to MS analyses. Description is shown in Table 7 and results in Table 8.

Sample

Description of origin

Date of extraction

2.16

Hot collector, HC-SG-11

15.03.04 9:00 h.

2.17

Cold collector, SC-SG-11.

15.03.04 9:00 h.

2.18

SG11 sediments

16. 03.04 10:00 h.

2.19

SG11 sediments cooler (surface of pipelines)

16. 03.04 10:00 h.

Table 7. Specimens from SG11 analysed in 2004

The dominant phase composition of the studied corrosion products taken from SG11 was hematite Fe2O3 (66,4% at hot collector, 80,8% at cold collector). The rest is from magnetite Fe3O4 presented by two sextets H2 a H3 with 31,7%, resp.18,1% contribution. The last component is paramagnetic doublet D1, which is assumed to be iron hydrooxides — high probably lepidocrockite (gamma FeOOH) presented by 1,9% and 1,1%, respectively.

The magnetite presence in all samples is almost stoichiometric (see the ratio Fe3+/ Fe2+ which tends to 2,0).

A significantly lower presence of magnetite in case of hot collector can be devoted from 2 parallel factors:

1. Difference in temperature (about 298°C at HC) and (about 223°C at CC) and mostly due to

2. Higher dynamic of secondary water flowing in the vicinity of hot collector, which high probably removed the corrosion layer from the collector surface.