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Modeling the acoustic noise from a wave energy converter farm and its impact on marine mammals at the PacWave South site, offshore Newport Oregon

Renewable Energy

Harding, Jennifer L.; Preston, Leiph A.; Johnson, Erick; Roberts, Jesse D.; Jones, Craig A.; Raghukumar, Kaus; Hafla, Erin

Marine hydrokinetic devices, such as wave energy converters (WECs), can unlock untapped energy from the ocean's currents and waves. Acoustic impact assessments are required to ensure that the noise these devices generate will not negatively impact marine life, and accurate modeling of noise provides an a priori means to viably perform this assessment. We present a case study of the PacWave South site, a WEC testing site off the coast of Newport, Oregon, demonstrating the use of ParAcousti, an open-source hydroacoustic propagator tool, to model noise from an array of 28 WECs in a 3-dimensional (3-D) realistic marine environment. Sound pressure levels are computed from the modeled 3-D grid of pressure over time, which we use to predict marine mammal acoustic impact metrics (AIMs). We combine two AIMs, signal to noise ratio and sensation level, into a new metric, the effective signal level (ESL), which is a function of propagated sound, background noise levels, and hearing thresholds for marine species and is evaluated across 1/3 octave frequency intervals. The ESL model can be used to predict and quantify the potential impact of an anthropogenic signal on the health and behavior of a marine mammal species throughout the 3-D simulation area.

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Compaction of crushed salt for the safe containment – Overview of Phase 2 of the KOMPASS project

Friedenberg, Larissa; Czaikowski, Oliver; Lerch, Christian; Muller Hoeppe, Nina; Rahmig, Michael; Bartol, Jeroen; Dusterloh, Uwe; Lerche, Svetlana; Saruulbayar, Nachinzorig; Lippmann-Pipke, Johanna; Laurich, Ben; Svensson, Kristoff; Zemke, Kornelia; Thiedau, Jan; Liu, Wenting; Gartzke, Anne; Popp, Till; Ludeling, Christoph; Rolke, C.; Rabbel, Ole; Reedlunn, Benjamin R.; Laros, James H.; Mills, Melissa M.; Coulibaly, Jibril B.; Spiers, Chris; De Bresser, Hans; Hangx, Suzanne; Van Oosterhout, Bart

Abstract not provided.

Validation study of sodium pool fire modeling efforts in MELCOR and SPHINCS codes

Nuclear Engineering and Design

Laros, James H.; Aoyagi, Mitsuhiro; Uchibori, Akihiro; Takata, Takashi; Luxat, David L.

Discharge of sodium coolant into containment from a sodium-cooled fast reactor vessel can occur in the event of a pipe leak or break. In this situation, some of the liquid sodium droplets discharged from the coolant system will react with oxygen in the air before reaching the containment. This phase of the event is normally termed the sodium spray fire phase. Unreacted sodium droplets pool on the containment floor where continued reaction with containment atmospheric oxygen occurs. This phase of the event is normally termed the sodium pool fire phase. Both phases of these sodium-oxygen reactions (or fires) are important to model because of the heat addition and aerosol generation that occur. Any fission products trapped in the sodium coolant may also be released during this progression of events, which if released from containment could pose a health risk to workers and the public. The paper describes progress of an international collaborative research in the area of the sodium fire modeling in the sodium-cooled fast reactors between the United States and Japan under the framework of the Civil Nuclear Energy Research and Development Working Group. In this collaboration between Sandia National Laboratories and Japan Atomic Energy Agency, the validation basis for and modeling capabilities of sodium spray and pool fires in MELCOR of Sandia National Laboratories and SPHINCS of Japan Atomic Energy Agency are being enhanced. This study documents MELCOR and SPHINCS sodium pool fire model validation exercises against the JAEA's sodium pool fire experiments, F7-1 and F7-2. The proposed enhancement of the sodium pool fire models in MELCOR through addition of thermal hydraulic and sodium spreading models that enable a better representation of experimental results is also described.

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Results 1226–1250 of 96,771
Results 1226–1250 of 96,771