No abstract

Accurate measurement of coolant flow rate is essential for determining the maximum power required by the nuclear plant operation and critical for monitoring its operation safety. However, no practical off-the-shelf flowmeter is available to satisfy all the pressing multidimensional operation requirements (i. e., high temperature, high irradiation, and high corrosion). This work thus deals with the development of a new flowmeter for nuclear power plant/reactor process-monitoring and real time analysis; this proposed flowmeter shall be able to continuously conduct robust measurements under extremely harsh environment with high irradiation, high pressure, high temperature and corrosive media. We investigate a transit-time based flow rate measurement which is used in such environment. The transit time of a thermal signal travels along with a liquid flow can be obtained using a cross correlation method. This transit-time-based flowmeter using thermocouples with grounded stainless steel shielding is by far the most robust and reliable solution to measure the flow rate in a harsh environment typically seen in a nuclear reactor. In practice, cross correlation calculation tends to produce flat peak plateau or multiple peaks, leading to a significant error in peak detection. To overcome this problem, in this work, an Auto-Adaptive Impulse Response Function estimation (AAIRF) technique is introduced and a significantly narrower peak is shown theoretically vi

Although Power Line Communication (PLC) is not a new technology, its use to support communication with low rate on low voltage (LV) distribution networks is still the focus of ongoing research. In this paper, we propose a PLC channel modeling method based on the bottom-up approach for LV PLC in a narrow, low frequency band between 9 kHz and 490 kHz. We employ the model to derive the transfer function of a typical LV PLC network, which is comprised of two common cable types (copper cables and aluminum conductor steel reinforced). We then investigate the multipath effect of the LV PLC in the studied low frequency bandwidth using numerical computations. Our simulation results based on the proposed channel model show an acceptable performance between neighboring nodes, in terms of bit error rate versus signal to noise ratio, which enables communication required for smart grid applications. Furthermore, we show that data transmission beyond one-hop communication in LV PLC networks will have to rely on upper layer protocols. © 2011 IEEE

In this paper, we propose an optimal Clipping/Blanking nonlinearity technique for impulsive noise reduction in narrowband (9 kHz-490 kHz) PLC system. This optimal technique is based on the minimum bit error rate (BER) search. For our simulation, we have derived the transfer function of a typical low voltage (LV) PLC network using the common bottom-up approach and scattering matrix method. Our simulation results, in terms of BER versus signal to noise ratio (SNR), show that the proposed technique improves the BER performance of the narrowband PLC system. © 2011 IEEE

No abstract