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Title: Calculation of local boron dilution accidents with the Hextran code

Abstract

Possibilities of Reactivity Initiated Accidents (RIA) due to local boron dilution slugs entering the core of PWRs have been widely studied in recent years. In Finland the main analysis tool for reactor dynamics RIA calculations has been the three dimensional HEXTRAN code which also includes full circuit models. Reliable calculation of propagating boron fronts is very difficult with standard numerical algorithms because numerical diffusion tends to smoothen the front. Thus the reactivity effect of the boron dilution can be significantly lowered and conservatism of the analyses cannot be guaranteed. In normal flow conditions this problem has been avoided in HEXTRAN analyses by simulating the dilution front directly to the core inlet. In natural circulation conditions there occurs significant numerical diffusion even during the propagation of boron front inside the core. Therefore a new hydraulics solution method PLIM (Piecewise Linear Interpolation Method) has been applied to HEXTRAN. Examples are given of analyses made with HEXTRAN in both flow conditions.

Authors:
;  [1]
  1. VTT Energy (Finland)
Publication Date:
OSTI Identifier:
459163
Report Number(s):
CONF-950420-
TRN: 97:007070
Resource Type:
Conference
Resource Relation:
Conference: International conference on mathematics and computations, reactor physics, and environmental analyses, Portland, OR (United States), 30 Apr - 4 May 1995; Other Information: PBD: 1995; Related Information: Is Part Of Proceedings of the international conference on mathematics and computations, reactor physics, and environmental analyses. Volume 1 and 2; PB: 1629 p.
Country of Publication:
United States
Language:
English
Subject:
22 NUCLEAR REACTOR TECHNOLOGY; 21 NUCLEAR POWER REACTORS AND ASSOCIATED PLANTS; PWR TYPE REACTORS; SAFETY INJECTION; COMPUTERIZED SIMULATION; H CODES; NATURAL CONVECTION; FINLAND; TRANSIENTS

Citation Formats

Kyrki-Rajamaeki, R, and Stenius, T. Calculation of local boron dilution accidents with the Hextran code. United States: N. p., 1995. Web.
Kyrki-Rajamaeki, R, & Stenius, T. Calculation of local boron dilution accidents with the Hextran code. United States.
Kyrki-Rajamaeki, R, and Stenius, T. 1995. "Calculation of local boron dilution accidents with the Hextran code". United States.
@article{osti_459163,
title = {Calculation of local boron dilution accidents with the Hextran code},
author = {Kyrki-Rajamaeki, R and Stenius, T},
abstractNote = {Possibilities of Reactivity Initiated Accidents (RIA) due to local boron dilution slugs entering the core of PWRs have been widely studied in recent years. In Finland the main analysis tool for reactor dynamics RIA calculations has been the three dimensional HEXTRAN code which also includes full circuit models. Reliable calculation of propagating boron fronts is very difficult with standard numerical algorithms because numerical diffusion tends to smoothen the front. Thus the reactivity effect of the boron dilution can be significantly lowered and conservatism of the analyses cannot be guaranteed. In normal flow conditions this problem has been avoided in HEXTRAN analyses by simulating the dilution front directly to the core inlet. In natural circulation conditions there occurs significant numerical diffusion even during the propagation of boron front inside the core. Therefore a new hydraulics solution method PLIM (Piecewise Linear Interpolation Method) has been applied to HEXTRAN. Examples are given of analyses made with HEXTRAN in both flow conditions.},
doi = {},
url = {https://www.osti.gov/biblio/459163}, journal = {},
number = ,
volume = ,
place = {United States},
year = {Sun Dec 31 00:00:00 EST 1995},
month = {Sun Dec 31 00:00:00 EST 1995}
}

Conference:
Other availability
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