Sensitivity and uncertainty analysis of βeff for MYRRHA using a Monte Carlo technique
Institute for Advanced Nuclear Systems, Belgian Nuclear Research Centre (SCK∙CEN),
2 J-PARC Center, Japan Atomic Energy Agency (JAEA), 2-4, Shirakata, Tokai-mura, Naka-gun, Ibaraki 319-1195, Japan
3 Data Bank, OECD Nuclear Energy Agency (NEA), 46, Quai Alphonse Le Gallo 92100 Boulogne-Billancourt, France
* e-mail: firstname.lastname@example.org
Received in final form: 26 January 2018
Accepted: 14 May 2018
Published online: 14 November 2018
This paper presents a nuclear data sensitivity and uncertainty analysis of the effective delayed neutron fraction βeff for critical and subcritical cores of the MYRRHA reactor using the continuous-energy Monte Carlo N-Particle transport code MCNP. The βeff sensitivities are calculated by the modified k-ratio method proposed by Chiba. Comparing the βeff sensitivities obtained with different scaling factors a introduced by Chiba shows that a value of a = 20 is the most suitable for the uncertainty quantification of βeff. Using the calculated βeff sensitivities and the JENDL-4.0u covariance data, the βeff uncertainties for the critical and subcritical cores are determined to be 2.2 ± 0.2% and 2.0 ± 0.2%, respectively, which are dominated by delayed neutron yield of 239Pu and 238U.
© H. Iwamoto et al., published by EDP Sciences, 2018
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