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DTRA’s advancements in nuclear and radiological detection
A new, more complex nuclear age has begun. Echoing the tensions of the Cold War amid rapidly evolving nuclear and radiological threats, preparedness in the modern age is a contest of scientific innovation. The Research and Development Directorate (RD) at the Defense Threat Reduction Agency (DTRA) is charged with winning this contest.
Mahmoud Z. Youssef, Insoo Jun
Fusion Science and Technology | Volume 15 | Number 2 | March 1989 | Pages 887-892
ITER Nuclear Design | doi.org/10.13182/FST89-A39806
Articles are hosted by Taylor and Francis Online.
In the initial design of TIBER-II inboard (I/B) shield, multilayers of tungsten shield and coolant were deployed with a total thickness of 48 cm. It was thought during the design process to replace W by PCA. The motivations are: (1) accumulated activation level in the I/B shield at shutdown is larger in the W-shield in comparison to the PCA-shield, and (2) concerns regarding cost/fabrication. This design change required an I/B shield thickness of ∼58 cm to reach the same performance level of the 48 cm W-shield. In this paper a detailed comparison between the two types of shield is given regarding the accumulated radioactivity, biological hazard potential (BHP), and afterheat levels at shutdown and various times thereafter. In addition, a substantial part of the present work is devoted to studying the impact of the present neutron cross-section uncertainties in the prediction of the radiation damage parameters in the S/C magnet. In this regard, an extensive cross-section sensitivity/uncertainty analysis was performed to assess the required increase in the I/B shield thickness in both cases to account for these uncertainties. It was shown that the economic penalty of such an increase is 13–17 M$ in the W-shield case as opposed to 10–14 M$ in the case of the PCA-shield.