[en] High capacity blowdown concept is applied in steam generator design for Korea Standard Nuclear Power Plant (KSNP) to remove sludge on tubesheet before solidification. NSSS system design adopted the operation mode as one of performance related design basis events, and proved that no adverse results happen such as reactor trip during high capacity blowdown operation. But KEPCO don't want to perform the operation for fearing of power reduction and the possibility of reactor trip due to SG level fluctuation. This report presents the performance analysis results for KSNP and the operation data for PVNGS related with the operation, to confirm the necessity of high capacity blowdown operation. (author)

[en] The computer program SAFE has been used to size and analyze the performance of a steam generator which has two types of heat transfer regions in Korean Standard Nuclear Power Plants (KSNP) and Korean Next Generation Reactor (KNGR) design. The SAFE code calculates the analytical boiling heat transfer area using the modified form of the saturated nucleate pool boiling correlation suggested by Rohsenow. The predicted heat transfer area in the boiling region is multiplied by a constant to obtain a final analytical heat transfer area. The inclusion of the multiplier in the analytical calculation has some disadvantage of loss of complete correlation by the governing heat transfer equation. Several comparative analyses have been performed quantitatively to evaluate the possibility of removing the multiplier in the analytical calculation in the SAFE code. The evaluation shows that the boiling correlation and multiplier used in predicting the boiling region heat transfer area can be replaced with other correlations predicting nearly the same heat transfer area. The removal of multiplier included in the analytical calculation will facilitate a direct use of a set of concerned analytical sizing values that can be exactly correlated by the governing heat transfer equation. In addition this will provide more reasonable basis for the steam generator thermal sizing calculation and enhance the code usability without loss of any validity of the current sizing procedure. (author)

[en] In this paper we first construct a two-parameter transformation group G on the space of test white noise functionals in which the adjoints of Kuo's Fourier and Kuo's Fourier-Mehler transforms are included. Next we show that the group G is a two-dimensional complex Lie group whose infinitesimal generators are the Gross Laplacian Δ_G and the number operator N , and then find an explicit description of a differentiable one-parameter subgroup of G whose infinitesimal generator is aΔ_G +bN . As an application, we study the solution and fundamental solution for the Cauchy problem associated with aΔ_G +bN . Finally we show that each element of the adjoint group G* of G can be characterized in terms of differentiation and multiplication operators