The safety concept in DIN 1055-100 [52] must be applied for the governing design situation:

Sd < Rd (7.1)

The design actions are to be calculated as per DIN 25449 [15], which defines the specific actions for nuclear power plants and nuclear facilities.

The design resistance is measured the equation:

Rd = Rk= gM (7-2)

The partial safety factor gM of resistance must be considered more closely here, as this has to be determined, not generally but specifically for the failure mode and require­ment category. For anchors, the partial safety factor gMc for concrete failure is obtained from three other partial safety factors gc, g2 and gA:

Y Mc = Vc’V 2’Ya (7-3)

where gc is the partial safety factor for concrete, depending on the requirement category. Partial safety factor g2 reflects the installation safety of the anchor and gA is the specific anchor partial safety factor for attachments in nuclear power plants. In requirement categories A2 and A3, the only anchors that may be used are those with a high installation safety g2 = 1.0. The value gA is set to give a partial safety factor for concrete failure of gMc = 1.5 under all conditions.

Turning to steel failure, the partial safety factor gMs is determined as a function of the load direction and material properties. For tensile loads applies:

For shear loads:

g Ms = !.5

fuk > 800N/mm2 orfyk/fuk > 0.8

7.1.4.1 Installation safety

In various nuclear power plants and nuclear facilities, there are many anchors that were not installed in the correct position, so they were replaced. According to [67], the
anchors used to attach safety-related components must be designed such that they can be checked easily to verify that they have been installed correctly from easily recognisable, objective and doubtless criteria when setting and once installation is completed.

If plans are not followed, the structural engineer must be consulted.

Anchor fastenings must always be installed in accordance with the manufacturers’ instructions, but there are numbers of other conditions which must also be observed:

— Incorrect drillings and damage to existing reinforcement should be avoided by detection.

— The anchoring plate connection area should be even, which can be achieved by applying a thin mortar smoothing layer.

— The distances required from edges causing disturbances must be maintained.

— Bores must be done at right-angles.

— Incorrect drillings must be closed with high strength concrete.

As evidence that anchor fastenings have been properly installed at nuclear power plants and nuclear facilities, an installation report must be produced for each attachment which must be verified by the client/operator and by a licensed structural engineer or the construction inspector. Instructions as to the content of such reports must be taken from those for use in nuclear power plant approvals. The data to be recorded for each location of anchor fastening are:

— application to change/notice of change

— date installed

— client’s/operator’s representative

— installation contractor plus professional construction manager for dowelling

— construction inspector

— fitter (training certificate)

— building

— area

— system

— anchor plate ID no.

— layout drawing

— workshop drawing

— anchor manufacturer

— product designation

— size

— material

— tools used

— borehole checks

— clean

— right-angled

— depth

— diameter

— incorrect drilling present/closed

— reinforcement damaged

— detectable cracks/local damage

— corrosive environment

— check torque

— check anchor plate

— made to workshop drawing

— plate thickness

— axis-edge distances

— through bore diameter

— concrete surface/thickness of smoothing layer at anchor

— check surroundings

— distances from adjacent fastenings

— geometric constraints.