Progress in High-Power-Particle Beams and Pulsed Power for Industrial Applications at Forschungszentrum Karlsruhe

Progress in High-Power-Particle Beams and Pulsed Power for Industrial Applications at Forschungszentrum Karlsruhe

H. Bluhm, V. An, K. Baumung, P. Brenner, L. Buth, V. Engelko^a, W. Frey, H. Giese, C. Gusbeth, A. Heinzel, P. Hoppé, G. Müeller, M. Sack, C. Schultheiss, J. Singer, R. Sträßner, A. Weisenburger

Forschungszentrum Karlsruhe GmbH, IHM, Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen, Germany ^aEfremov Institute of Electrophysical Apparatus, St. Petersburg, Russia

Abstract. In this paper we review the progress that has been achieved at Forschungszentrum Karlsruhe for several industrial scale projects based on intense particle beams and pulsed power technologies. Using intense large area pulsed electron beams thin layers at the surface of materials can be heated adiabatically above the melting point and through rapid cooling restructure or alloy the surface to improve the corrosion and wear resistance. This technique has been applied to solve the steel corrosion problem of future liquid Pb or Pb/Bi cooled accelerator driven nuclear reactors for transmutation of higher actinides and long living fission products. It has been proved that alloying the steel surface with the appropriate concentration of Al solves the corrosion problem both in stagnating and flowing Pb/Bi at temperatures up to 650° C. Further applications of pulsed electron beams to improve the properties of materials and machine parts for use under extreme conditions are discussed. A precession of the electron beam has been observed which is most likely caused by a magnetized ion hose instability resulting from a relative shift between the e-beam and a counter-stream of ions from the target. Pulsed electric fields can induce pores in the membrane of biological cells. This effect has been used to extract foodstuff from plant cells on a large scale and for bacterial contamination. New concepts have also been developed for the recycling of concrete contaminated with mineral oil. These concepts are based on the enrichment of contaminants in the fine fraction of concrete fragmented with electric pulses. All applications are based on synchronous operation of several Marx generators. For that purpose a new durable trigger system for spark gap switches has been developed.

Introduction

In this paper we describe recent contributions of pulsed power and beam technologies to a program on sustainable development and technology conducted at Forschungszentrum Karlsruhe. It is the aim of this program to investigate how innovative technologies can contribute to changes in certain areas of industrial activity required to approach the general goal of sustainability.

Our contributions are related to nuclear and fossil energy production, to the effective use and regeneration of natural resources, and to the recycling of building materials.

CONTRIBUTIONS TO SUSTAINABLE ENERGY PRODUCTION

It is generally accepted that a reduction of the radiotoxicity of waste from nuclear power plants could mitigate the problem of ultimate waste disposal.

A Pb or Pb/Bi cooled accelerator-driven reactor possessing a high energy neutron spectrum is presently developed in Europe, Japan and the USA for transmutation of long living fission products, plutonium and the higher actinides. However a solution of the strong corrosion of reactor steel in liquid Pb or Pb/Bi at high temperatures is required before such a reactor can be established. As described at the last Beams meeting [1] a possible solution is to alloy a layer of the steel surface with a high percentage of Al by co-melting an aluminum layer and a surface layer of the steel with the help of a pulsed large area intense electron beam.

The electron beam generators GESA I and II used for that purpose have been described previously [1]. The surface treatment of materials with pulsed electron beams is based on rapid adiabatic melting of a thin surface layer followed by fast quenching of the molten layer through heat conduction into the unaffected cold bulk material.

Since the last Beams meeting long term corrosion tests of treated steel probes have been extended to 10000 h in both stagnant and flowing Pb/Bi. The loop tests have been carried out in the new KALLA laboratory at Forschungszentrum Karlsruhe and in the loops of Prometey, St. Petersburg and IPP Obninsk. Our investigations have been focused martensitic steels licensed for fuel element cladding and on austenitic (AISI 316 L) steel licensed for the reactor pressure vessel. It was found that austenitic steel because of its high Ni content could only be used at temperatures below 500° C while martensitic steel can be applied up to 550° C. However the thick fast growing protective oxide layers always have a tendency to flake off. All steels whose surface had been alloyed with Al using the GESA technology showed excellent corrosion resistance up to 650 °C.