In-Service Inspection of Nuclear Power Plants - gnssn - International ...

This publication is no longer valid
Please see http://www-ns.iaea.org/standards/
Doc.-No.
KKG-Q-PSOO5
NUCLEAR POWER PLANT GOESGEN-DAENIKEN LTD
Annex. 5
Page- 2
out of: 2
Rev.
With nozzle welds the fillet must always be included in the examination
area, i.e. the yoke magnet is to be placed in the weld area as shown
under 1.1 and in the fillet area as shown in 1.2.
Since the contact area of the yoke magnet with the test surface is limited
with nozzle welds, adequate field strength must be demonstrated in respect
of each weld by means of a tangential field strength measuring instrument.
Jf magnetization is insufficient, another test technique or method, e.g.
circular magnetization or liquid penetration, must be applied.
2. Basic material testing
Large surfaces on vessels etc. are to be divided into squares of max. 100 mm
side length.
6
c'
D
A
D
\E -Q D'
B
o
\
A'
O
4
cm
Test area
\
D
O
a
D'
a
Sequence:
AA-A'A 1
BB-B'B 1
CC-C'C
DD-D'D'
Check with the Berthold magnetic
field indicator whether there
is sufficient magnetization,
and if not, select further
intermediate positions.
135