Prestressed concrete containment of nuclear power station with PWR

The initial steps of the development of prestressed concrete containment (PCC) for nuclear power plant (NPP) with pressurized water reactors (PWR) in the former USSR are analyzed. The constructive and technological decisions, accepted for primary PCC of Novovoronez NPP, such as the positioning of reinforcement elements and seaths in cylindrical wall and dome of the containment, the anchorage of reinforcement element ends, the technological aspects of concrete works, system and technology of a high level of biaxial pressing on a thin-wall structure at large wrapping angles of power reinforcing strands and etc. are observed. Experience won through the construction and operation of the primary PCC served as a basis for development of a new generation of improved unified PCC (IUPCC) for serial NPP, equipped with PWR of capacity of 1000 MW. The IUPCC is actually a cylinder 45 m in diameter and 54-m high covered with a gently sloping spherical dome. Thickness of cylinder wall is 1200 mm and that of dome wall is 1100 mm. The principle novelty of this PCC is the type and positioning of reinforcement strands. The paper describes strand arrangement and their anchorage in IUPCC. In the vertical part of PCC, strands are arranged on a helical-loop scheme and both strand ends are firmly anchored at the ring girder. Each strand is bended at the bottom of the containment. In the dome, strands are grouped on the orthogonal-loop scheme with the anchorage on one side and with bend of loop on the opposite side of the ring girder. To prevent the leakage of gases and to ensure tightness of the IUPCC an inner metal 8-mm liner with special anti-corrosion coating is designed. Monitoring and checking the stress and strain state of IUPCC is possible during the building, testing as well as operating periods. If any defects or decreased prestress of concrete are detected it is possible to tighten or replace the strands. It is noted that the more than 20 IUPCCs are in-service in Russia, Ukraine, and Bulgaria where NPP with PWR of capacity of 1000 MW were constructed.     

Mechanisms of Active Fuzzy Expertise

Consideration was given to the decision making procedures based on the fuzzy messages of experts whose preferences on the set of collective decisions can also be fuzzy.     

Eliminating memory for fragmentation within partitionable SIMD/SPMDmachines

Efficient data layout is an important aspect of the compilation process. A model for the creation of perfect memory maps for large-scale parallel machines capable of user-controlled partitionable single-instruction-multiple data/single-program-multiple data (SIMD/SPMD) operation is developed. The term perfect implies that no memory fragmentation occurs and ensures that the memory map size is kept to a minimum. A major constraint on solving this problem is based on the single program nature of both the SIMD and SPMD modes of parallelism. It is assumed that all processors within the same submachine used identical addresses to access corresponding data items in each of their local memories. Necessary and sufficient conditions are derived for being able to create perfect memory maps, and results are applied to several partitionable interconnection networks     

Measurements of neutron induced nucleation

The paper describes new experimental evidence on the effects of fast neutron irradiation on the nucleation of bubbles in superheated demineralized water during sudden depressurization. The experimental range covered strating pressures of (0.33–6.0) MPa. It was shown that fast neutron irradiation causes significant increases in the bubble formation for specified conditions of pressure, temperature and rate of blowdown. A mechanistic interpretation of the measurements based on a thermodynamic model was included, and comparison was made, in terms of void fraction, with the experimental results.     

The evolution of RFID security

As RFID technology progresses, security and privacy threats also evolve. By examining RFID's history, we can learn from past mistakes, rediscover successful solutions, and inspire future research.