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Latest News
DOE issues RFQ for clean-energy projects at WIPP
The Department of Energy has issued a request for qualifications (RFQ) for interested parties that are looking to establish carbon pollution–free electricity (CFE) projects at its Waste Isolation Pilot Plant site in New Mexico.
Richard Sanchez
Nuclear Science and Engineering | Volume 177 | Number 1 | May 2014 | Pages 19-34
Technical Paper | doi.org/10.13182/NSE12-95
Articles are hosted by Taylor and Francis Online.
We investigate the degeneracy of the first-order PN equations and construct interface and boundary conditions that ensure a unique solution. Our technique is based on establishing an equivalence between the first- and second-order PN equations and showing that the (regular) second-order equations with opposite parity to N are nondegenerate. Assuming bounded angular flux moments and sources, we derive interface and boundary conditions for the regular second-order equations that, via the equivalence, are those to be used with the first-order PN equations. While providing independent derivations, our results reproduce those derived using solid harmonic expansions by Davison and Rumyantsev in the 1950s.