Modelling fluid-structure interaction of water recirculating flow to predict damage and/or failure in a jet-pump assembly of a nuclear boiling water reactor

The structural integrity of a jet pump assembly of a boiling water reactor (BWR) under hydrodynamic loading was evaluated. This arrangement, which has a riser joined with a couple of jet pumps by the transition piece, is part of the reactor recirculation system. It is submerged in water under pressure. The main function is to induce forced flow through the core of the reactor. A dynamic structural analysis was carried out with the finite element method. The first ten modes of vibration and their natural frequencies were calculated. The first five natural frequencies are in the range between 25 Hz and 40 Hz. In this analysis, it was considered that the jet pump assembly is supported at the riser brace. The restrainer bracket keeps together the riser with the two jet pumps and there is free movement at the slip joints.

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ICONE11-36020 COUPLED FLUID-STRUCTURE INTERACTION ANALYSIS OF LIGHT WATER REACTOR INTERNALS WITH PHASE CHANGE

The Proceedings of the International Conference on Nuclear Engineering (ICONE) ◽

10.1299/jsmeicone.2003.48 ◽

2003 ◽

Vol 2003 (0) ◽

pp. 48

Author(s):

R. K. Singh ◽

H. S. Kushwaha ◽

V. Venkat Raj

Keyword(s):

Phase Change ◽

Interaction Analysis ◽

Fluid Structure Interaction ◽

Light Water Reactor ◽

Fluid Structure ◽

Light Water ◽

Water Reactor ◽

Structure Interaction ◽

Reactor Internals

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Boiling Water Reactor Jet Pump Acoustic Loads Resulting From a Recirculation Outlet Line Break Loss of Coolant Accident: Some Sensitivity Studies

ASME 2010 Pressure Vessels and Piping Conference: Volume 4 ◽

10.1115/pvp2010-25866 ◽

2010 ◽

Author(s):

Daniel V. Sommerville ◽

Raju Ananth

Keyword(s):

Boiling Water ◽

Boiling Water Reactor ◽

Jet Pump ◽

Element Analysis ◽

Water Reactor ◽

Loss Of Coolant Accident ◽

Loss Of Coolant ◽

Acoustic Load ◽

Jet Pumps ◽

Sensitivity Studies

Acoustic loads caused by a Recirculation Line Break Loss of Coolant Accident are a required design basis event that must be considered for stress analyses of Boiling Water Reactor internal components such as Jet Pumps. This event causes acoustic and fluid loads on BWR internals. These loads must also be considered for fracture mechanics evaluations performed to assess allowable operating periods for flaws detected during in-service inspections. Acoustic loads methods generally utilized in the past have been 1-D or simplified 2-D models of the domain of interest. These models generally do not enable accurate assessment of the variation of acoustic loading on jet pumps away from the break plane. Previous methods conservatively apply the acoustic loading predicted for the jet pump nearest the break for all jet pumps. Insight can be gained and lower loading may be justifiable, for jet pumps away from the break, using methods that enable accurate acoustic load predictions for all jet pumps in the BWR annulus. This paper presents the results of Recirculation Line Break acoustic loads analyses of a typical BWR and investigates the variation of acoustic loading between all jet pumps in the annulus. The paper also presents the results of preliminary sensitivity studies performed to identify which geometric characteristics of the BWR annulus have the most significant effect on the resulting acoustic load predictions. The analyses documented in this paper are performed using acoustic finite element analysis.

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