consideration of higher seismic loads at existing plants · 2016. 3. 4. · seismic loads. areva...
TRANSCRIPT
The devices of safety-related electrical
and I&C equipment (e.g. cabinets or
switchgears) have to maintain
functional during and after an
earthquake. The electrical devices
used for such equipment cannot be
easily upgraded in terms of
robustness. Therefore, for the
supporting structures, (e.g. cabinets)
the natural frequencies have to be
tuned in such a way that the
acceleration level for the electrical
devices will not increase. The
shift of natural frequencies
can be achieved by
� upgrading the robustness of the
cabinet structure itself
� implementing additional
supporting structures for cabinets.
Building structuresThe pushover analysis of a structure is a static non-linear analysis
under permanent vertical loads and gradually
increasing equivalent lateral loads. These
approximately represent earthquake induced
inertia forces. The analysis is carried out up
to structural failure; in this way, the actual
capacity of the structure is determined. -30.00 -20.00 -10.00 0.00 10.00 20.00 30.00
Consideration of Higher Seismic Loads at Existing Plants
Interlinked expertise for all domains related to
seismic loading and seismic verification of safety
related systems
AREVA has interlinked expertise for all domains related to seismic
loading and seismic verification of safety related systems :
� Structural dynamics of civil structures (buildings), NSSS
equipment and large components, and soil structure interaction
� Distribution lines and auxiliary equipment
� Electrical and I&C equipment
In case of increased seismic requirements, AREVA has the ability to
provide adequate methods for re-evaluation:
� Application of experience-based screening
methods for re-assessment
� Re-assessment by realistic dynamic simulation
and structural evaluation
� Re-verification / exchange or upgrade of equipment or structures
Due to a renewed probabilistic seismic hazard
analysis, plenty of existing plants face higher
seismic loads.
In such cases, national authorities require a re-
evaluation or re-qualification of safety related
structures and equipment for the increased
seismic loads.
AREVA presents solutions for various safety
related structures and equipment inside the plant,
avoiding hardware exchange.
Electrical and I&C Equipment
Reevaluation of mechanical equipmentThe re-evaluation of mechanical equipment will be performed by
load comparison or by numerical calculation. Necessary
reinforcements will be defined, planned and installed according to
the requested national standards.
Seismic margin assessment and seismic PSAAs opposed to the analysis of individual structures and components,
plant level margin assessments and probabilistic safety analyses
(PSA) evaluate the impact of seismic loads on the plant in its entirety
and are typically an integral part of periodic safety evaluations or
post-Fukushima robustness verifications.
AREVA has specific expertise in each of the topic areas (PSA
modeling, experience-based screening, robustness evaluation of
equipment via walkdown, detailed fragility analysis of structures
and equipment, for analysis- and test-qualified equipment).
Contact