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November 9–12, 2025
Washington, DC|Washington Hilton
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Amazon provides update on its Washington project with X-energy
A year ago this month, Amazon led a $500 million investment in X-energy, alongside Citadel founder Ken Griffin, the University of Michigan, and other investors. In addition to that financing, Amazon pledged to support the development of an initial four-unit, 320-MW project with Energy Northwest in Washington state.
M. M. R. Williams
Nuclear Science and Engineering | Volume 155 | Number 1 | January 2007 | Pages 109-118
Technical Note | doi.org/10.13182/NSE05-73TN
Articles are hosted by Taylor and Francis Online.
The polynomial chaos functions of Wiener are used to solve a stochastic differential equation. It is shown that a variety of polynomials are available according to the probability distribution of the underlying random element. Using the Legendre chaos polynomials, we have solved the problem of radiation transmission through a slab of random material properties in the P1 approximation. For a special case, it is possible to obtain an exact solution to this problem, and hence the rate of convergence of the chaos expansion can be examined. Results are shown in tabular form and graphically, which compare the stochastic average with the deterministic average and significant differences are found. In addition we calculate the variance in the flux and current across the slab, thereby giving a measure of the uncertainty associated with the average. The method of polynomial chaos offers an alternative procedure to the normally used closure, or special statistics, methods for the study of spatial randomness and has the potential to deal with very complex systems, although the full computational implications have yet to be determined. In the Appendix, we show how the Boltzmann equation, with spatially random cross sections, can be reduced to a coupled set of deterministic equations.