NOVELTY - Processing of materials such as a biomass material involves conveying a biomass material through a first enclosure (302) and exposing the biomass material to a first dose of ionizing radiation to produce a first treated biomass material; and conveying the first treated biomass material through a second enclosure (304) and exposing the first treated biomass material to a second dose of ionizing radiation to produce a second treated biomass material.    USE - For processing of materials such as biomass (claimed) i.e. plant biomass, animal biomass and municipal waste biomass to produce useful intermediates and products such as energy, fuels, foods or materials e.g. sugars such as xylose and glucose, and alcohols such as ethanol and butanol.    ADVANTAGE - The method and system facilitates production from a biomass material, increasing throughput, safety and costs associated with treatment of biomass. The method involves irradiation, thus the throughput can be increased by multiple irradiations with more than one irradiation device. Hazards is mitigated and safety enhanced by enclosing the irradiation devices in radiation opaque enclosures, i.e. vault. The energy and material costs is reduced associated with the building materials used to construct the vault and transportation or conveying of the biomass between vaults during processing by sharing of walls between vaults. The methods and systems include at least two treatment vaults and share at least one common wall. Processing the feedstock such as cellulosic and/or lignocellulosic material with irradiation, including more than one dose of radiation increases the throughput of processing, and reduces its recalcitrance utilizing two vaults. Sharing two or more common walls, access to equipment associated with one irradiation device does not require other irradiation devices in other vaults to be taken off line (i.e. the vault that is not in use is by-passed by diverting the flow of biomass to other vaults with operating irradiators). The method allows continuous treatment of biomass.    DETAILED DESCRIPTION - An INDEPENDENT CLAIM is included for a biomass treatment facility comprising first conveying system (325) configured to convey a biomass material through first enclosure while exposing the biomass material to first dose of ionizing radiation from first electron accelerator (370) to produce a first treated biomass material; and second conveying system configured to convey the first treated biomass material through second enclosure while exposing the first treated biomass material to second dose of ionizing radiation from second electron accelerator to produce a second treated biomass material.    DESCRIPTION OF DRAWING(S) - The figure shows top side view of two vaults for treating biomass.    First enclosure (302)    Second enclosure (304)    Common wall (310)    Conveying system (325)    Electron beam accelerator (370)    Power source (380)    Electrical conduit (382)    Rails (390, 391)    Vent system (395)