Computer analyses on loop seal clearing experiment at PWR PACTEL

Kauppinen, Otso-Pekka; Kouhia, Virpi; Riikonen, Vesa; Hyvärinen, Juhani; Sjövall, H.

doi:10.1016/j.anucene.2015.04.036

Cited by 10 publications

(2 citation statements)

References 11 publications

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“…3 the schematic diagram of the APROS nodalization. Both nodalizations have been utilized and developed within the PWR PACTEL related projects such as with the loop seal clearing experiment case (Kauppinen et al, 2015). Both nodalizations are 1D models including all the main components of the PWR PACTEL facility, such as the pressure vessel, two primary loops with inverted U-tube steam generators, pressurizer, and secondary sides of the steam generators.…”

Section: Pwr Pactel Nodalizationsmentioning

confidence: 99%

System code analysis of accumulator nitrogen discharge during LOCA experiment at PWR PACTEL test facility

Kauppinen

Kouhia

Riikonen

et al. 2019

Nuclear Engineering and Design

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The hydroaccumulators in pressurized water reactors can inject nitrogen into the reactor system. In the primary system, nitrogen affects core cooling and accident management, both adversely and beneficially. The PWR PACTEL experiment NCG-13 have shown that during a hot leg SB LOCA, nitrogen in the primary side can block the primary to secondary heat transfer and thereby prevent the primary depressurization to the point needed for the long-term accident management. This paper presents the APROS and TRACE calculations of the PWR PACTEL NCG-13 experiment. Both codes calculate the transient progression and the timing of the main events satisfactorily, once the suitable options are selected and adjustments made. There is, however, one big discrepancy between the code simulations and the experiment: in the simulations, much more nitrogen is needed to get qualitatively the same behaviour. The difference is a factor of 2.5 by mass for stopping the depressurization and 4-6 to cause a core heat-up. This is of concern regarding the confidence in the codes, as the simulations underestimate the adverse effect of nitrogen on the core coolability. HIGHLIGHTS: Codes predict the transient behaviour and timing of the main events satisfactory  In the simulations, nitrogen stops the primary side depressurization  Amount of released nitrogen is larger in the simulations than in the experiment *Highlights (for review)

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Section: Pwr Pactel Nodalizationsmentioning

confidence: 99%

System code analysis of accumulator nitrogen discharge during LOCA experiment at PWR PACTEL test facility

Kauppinen

Kouhia

Riikonen

et al. 2019

Nuclear Engineering and Design

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“…As a result, a possibly significant passive residual decay heat removal from the reactor's primary coolant system is established [1][2][3] . Reflux condensation can occur at high pressures 4-10 MPa, due to a loss of coolant accident (LOCA) during normal plant operation [4][5][6][7][8] or at containment pressures due to loss of residual heat removal (RHR) system during a mid-loop inventory operation [9][10][11] .…”

Section: Introductionmentioning

confidence: 99%