title: Application of MCBEND to PBMR shielding analysis.
abstract: Shielding analysis of an early design of Pebble Bed Modular Reactor (PBMR) has been carried out by using the Monte Carlo code MCBEND. The issues of concern were damage to the core barrel and the reactor pressure vessel (RPV), activation of the core barrel, RPV, top plate and bottom plate, and also burn-up of boron in the control layer underneath the core. The analysis below the core was complicated due to the presence of the de-fuelling chute, which meant that multiplication had to be taken into account. The analysis of boron burn-up was particularly challenging and was tackled using a combination of MCBEND and the criticality code MONK in the depletion mode. The application of MCBEND to the shielding analysis of the PBMR is described, with particular attention being paid to the regions below the core.
authors.affiliation: Serco Assurance, Winfrith, Dorchester, Dorset, UK. george.wright@sercoassurance.com
authors.forename: G A
authors.initials: GA
authors.lastname: Wright
authors.forename: S J
authors.initials: SJ
authors.lastname: Wall
mesh_terms: D000465:Algorithms; D003198:Computer Simulation; D004868:Equipment Failure; D019544:Equipment Failure Analysis / Q000379:methods; D005160:Facility Design and Construction / Q000379:methods*; D015233:Models, Statistical; D009502:Neutrons; D009688:Nuclear Reactors; D011829:Radiation Dosage; D011834:Radiation Monitoring / Q000379:methods*; D011835:Radiation Protection / Q000295:instrumentation* / Q000379:methods*; D012984:Software; D006113:United Kingdom