Evaluation of Prompt Dose Environment in the National Ignition Facility during D-D and THD Shots

• Published in: Fusion science and technology 2009-08, Vol.56 (2), p.697-701
• Main Authors: Khater, Hesham, Dauffy, Lucile, Sitaraman, Shiva, Brereton, Sandra
• Format: Article
• Language: English
• Subjects: DOORS; ENGINEERING; EVALUATION; Exact sciences and technology; FUSION YIELD; GENERAL STUDIES OF NUCLEAR REACTORS; Monte carlo methods; NEUTRONS; Physics; Physics of gases, plasmas and electric discharges; Physics of plasmas and electric discharges; Plasma simulation; PRODUCTION; RADIATION PROTECTION AND DOCIMETRY; ROOFS; SHIELDING; SHIELDS; TARGET CHAMBERS; TARGETS; THERMONUCLEAR REACTORS; US NATIONAL IGNITION FACILITY
• ISSN: 1536-1055; 1943-7641
• DOI: 10.13182/FST09-697

Evaluation of the prompt dose environment expected in the National Ignition Facility (NIF) during Deuterium-Deuterium (D-D) and Tritium-Hydrogen-Deuterium (THD) shots have been completed. D-D shots resulting in the production of an annual fusion yield of up to 2.4 kJ (200 shots with 10 13 neutrons per shot) are considered. During the THD shot campaign, shots generating a total of 2x10 14 neutrons per shot are also planned. Monte Carlo simulations have been performed to estimate prompt dose values inside the facility as well as at different locations outside the facility shield walls. The Target Chamber shielding, along with Target Bay and Switchyard walls, roofs, and shield doors (when needed) will reduce dose levels in occupied areas to acceptable values during these shot campaigns. The calculated dose values inside occupied areas are small, estimated at 25 and 85 μrem per shot during the D-D and THD shots, respectively. Dose values outside the facility are insignificant. The nearest building to the NIF facility where co-located workers may reside is at a distance of about 100 m from the Target Chamber Center (TCC). The dose in such a building is estimated at a fraction of a rem during a D-D or a THD shot. Dose at the nearest site boundary location (350 m from TCC), is caused by skyshine and to a lesser extent by direct radiation. The maximum off-site dose during any of the shots considered is less than 10 nano rem.