International Topical Meeting on Nuclear Research Applications and Utilization of Accelerators

4-8 May 2009, Vienna

Estimation of Acceptable Beam Trip Frequencies of Accelerators for ADS and Comparison with Experimental Data of Accelerators

H. Takei¹, K. Nishihara¹, K. Tsujimoto¹, H. Oigawa¹, K. Furukawa², and Y. Ogawa²

¹Japan Atomic Energy Agency (JAEA), Tokai, Japan
²High Energy Accelerator Research Organization (KEK) Tsukuba, Japan

Corresponding Author: takei.hayanori@jaea.go.jp

Frequent beam trips as experienced in existing high power proton accelerators may cause thermal fatigue problems in ADS components which may lead to degradation of their structural integrity and reduction of their lifetime. Thermal transient analyses were performed to investigate the effects of beam trips on the reactor components, with the objective of formulating ADS design considerations, and to determine the requirements for accelerator reliability. These analyses were made on the thermal responses of four parts of the reactor components; the beam window, the cladding tube, the inner barrel and the reactor vessel. Our results indicate that the acceptable frequency of beam trips ranges from 43 to 2.5 x 10⁴ times per year, depending on the beam trip duration.

In order to consider measures to reduce the frequency of beam trips on the high power accelerator for ADS, we compared the acceptable frequency of beam trips with the operation data of existing accelerators. The result of this comparison shows that for typical conditions the beam trip frequency for durations of 10 seconds or less is within the acceptable level, while that exceeding 10 seconds should be reduced to about 1/15 to satisfy the thermal stress conditions.

Full text paper