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The two reactors at Dominion Energy’s Surry plant are among the oldest in the U.S. nuclear fleet. Yet when the plant celebrated its 50th anniversary in 2023, staff could raise a toast to the future. Surry was one of the first plants to file a subsequent license renewal (SLR) application, and in May 2021, it became official: the plant was licensed to operate for a full 80 years, extending its reactors’ lifespans into 2052 and 2053.
Zelmo Rodrigues de Lima, Aquilino Senra Martinez, Fernando Carvalho da Silva, Antonio Carlos Marques Alvim
Nuclear Science and Engineering | Volume 170 | Number 1 | January 2012 | Pages 66-74
Technical Note | doi.org/10.13182/NSE10-67TN
Articles are hosted by Taylor and Francis Online.
Cross sections are homogenized over an entire node in nodal model implementation. The presence of a control rod (CR) partially inserted in the node has occasioned axial heterogeneity and generates a homogenization problem. If the homogenization process is only the volume-weighted average for nuclear parameters, the calculation of the multiplication factor and power in steady-state problems may mean relevant errors and for time-dependent problems may have caused the well-known cusping problem, which arises in three-dimensional transient simulations with CR motions. The major purpose of this technical note is to introduce an alternative method, based on the nodal expansion method, to deal with partially inserted CRs in nodes. One-dimensional equations, acquired through transverse integration of the neutron diffusion equation, have been modified to formulate the alternative method, which was evaluated in a transient problem. Furthermore, the alternative method gives satisfactory results and corrects the cusping effect in the case analyzed in this technical note.