Analysis of Various Concepts for RW Class 1 Disposal in Crystalline Rocks

The paper considers most elaborated concepts for SNF and HLW disposal in crystalline rocks. It explores in detail an alternative concept suggesting the use of a super-container (SC) with a bentonite buffer located inside a steel body and the SC itself located in vertical wells inside a cement backfill, which is also used to seal fractures crossing the wells.

Analysis of Possibility of Repairing Welding of Selected of the Steam Turbines

The article presents the results of the study on the possibilities of repair by welding methods of exploitation steam turbine bodies. Two hull were investigation after a lifetime of more than 200.000 hours. Repair welding study were carried out on the L17HMF cast steel body in the immediately after exploitation condition, whereas the L21HMF cast steel body underwent a revitalization after the exploitation, and then the welding repair research were performed. On the material taken from the L17HMF cast steel hull, welding repairs were made by welding the previously cut four grooves measuring 200 mm 50 mm 50 mm, which were simulations of material defected. All samples were made in areas where maximum steam temperatures were operating. Welds were tested with destructive and non-destructive methods to determine their quality and define non-compliances detected. The L21HMF cast steel was subjected to a revitalization process, which consisted the hull in subjecting heat treatment in order to obtain favourable structural changes and improve the strength properties. Non-destructive examinations and hardness tests were carried out on the remedial weld, indicating the required quality of repairing remedial weld. Comparative study is aimed at demonstrating the main welding problems during the repair welding of exploitation steam turbine hulls.

Piezoelectric Sensor Signal Analysis after Interface Changes between the Sensor and the Structure under Monitoring

This study aims to show the influences of the sensor installation interface in the industrial environment. This contribution is focused on analyzing the response behavior of piezoelectric transducers subjected to successive installations, using digital signal processing and non-destructive structural health monitoring (SHM) techniques. Tests were performed to simulate the installation conditions of a piezoelectric sensor, which was coupled to a holder carrying a steel body and submitted to successive reinstallations. Different signals were obtained for each installation, and the results can bring initial elucidations on the subject and pave the way for future studies.

Directions for increasing conical picks’ durability

Conical picks are cutting tools used in many branches, in particular in the mining, road construction and building branch. Contact with the excavated face causes their constant wear, which is an unfavorable but unavoidable process. Milling heads of working machines are equipped with several dozen conical picks, and mining in abrasive or hardly accessible rocks can reduce their life to a few hours. It is in the interest of both users and producers to increase their durability, as tools replacement, apart from purchase and logistic costs, results in machine downtimes. In the article various solutions of conical picks, their construction, dimensions and materials used have been discussed. Technical procedures applied to increase the durability of conical picks and their regeneration as well as methods of extending the life of picks working in difficult conditions have been presented. Two author’s methods of extending the life of picks working in difficult conditions, covered by a patent application, have also been presented. The first solution involves ensuring an uninterrupted rotational movement of the pick in the holder. Patent claims include an innovative method of equipping the additional sleeve integrated with the holder with a rotational bearing, which enables a continuous rotation of the pick. The tool equipped with a bearing generates much lower movement resistance than the standard mounting. The holder is designed to mount classic commercial picks. What is important, the pick replacement does not require interfering with the bearing assembly. The second solution concerns the manner of protecting the working part of the pick by means of a special element made of an abrasion resisting material. This element is the pick tip, the geometry of which varies from the commonly applied posts made of sintered carbide. In this solution, the tip has a shape corresponding to the form of conical pick’s wear, which causes that its steel body does not wear. Moreover, there is a possibility of applying a mobile, rotational mounting of the tip to the body.