GOTHIC Model Research Articles

Art Deco Architecture in Pune from the 1940s to the 1960s

Art Deco is a visual arts, architecture, and product design style. It first emerged in Paris in the 1910s, shortly before World War I. This style reached its height in Europe and the United States in the 1920s and early 1930s. The early to mid-1930s saw the emergence of Art Deco architecture in India, which ended in the mid to late 1950s. Indian cities like Mumbai, Pune, Chennai, Jaipur, Jodhpur, and Patiala are home to Art Deco structures. In terms of architecture, the Art Deco movement represented a dramatic departure from the colonial Neo-Gothic/Victorian Gothic model. The pursuit of modernity, multiculturalism, and cosmopolitanism were all reflected in Art Deco architecture. UNESCO declared the Victorian Gothic and Art Deco ensembles of Mumbai (Maharashtra’s capital) a UNESCO World Heritage Site in June 2018. Nevertheless, Pune City’s Art Deco buildings are not recognized as heritage buildings or documented. The study involved photographic documentation of Art Deco buildings in Deccan, Swargate Prabhat Road, Bhandarkar Road area of Pune. This paper examines the various motifs and their underlying symbolism that can be seen in Pune’s Art Deco buildings. The results of this study show that the Art Deco buildings in Pune are now on the verge of extinction due to the age of the building, structural deformities and lack of awareness of the conservation of this historical heritage. The art deco features on the elevations of many buildings have been hidden/erased by renovation and commercial hoardings.

Vernacular classicism and the Mausoleum of Halicarnassus: the architectural imaginary of a Danish interwar crematorium

Abstract This article discusses a crematorium inaugurated in 1923 in the municipal Northern Cemetery (Nordre Kirkegård) of Aarhus as a case of vernacular classicism in interwar Denmark. While earlier works by its architect Sophus Frederik Kühnel (1851–1930) followed National Romantic, Renaissance, and Gothic models, the crematorium stands out because of its crowning feature, a stepped pyramid roof that emulates one of the most characteristic architectural elements of the mid-fourth-century BCE Mausoleum of Halicarnassus, described by Pliny the Elder (HN 36.31) and other ancient authors. This reference to one of the most famous funerary monuments from classical antiquity is both functionally and symbolically appropriate in a cemetery setting and also fits into a longer history of ‘Mausoleumania’, both in Denmark and internationally. Furthermore, it reflects a broader architectural movement of vernacular, ‘Nordic’ classicism during the interwar period, when local architects ‘translated’ classical elements into the vernacular, for example, through prominent use of brickwork and eclectic combinations of classical motifs with both medieval and National Romantic forms. Kühnel’s crematorium shows some of the creative ways in which Scandinavian architects freely adapted distinctive elements from the repertoire of classical architecture, in this case in response to the rise of cremation.

MOBY-DICK, MODERNISM AND THE “POST-DEATH” NARRATION

There is a peculiar tendency among many first-person Modernist narrators to simulate the narrative perspective of “posthumousness” (as if these accounts were somehow narrated by the dead). The procedure (that could be termed the “post-death narration”) seems to be present in various proto-modernist and Modernist works such as Conrad's Heart of Darkness, Faulkner's The Sound and the Fury and Absalom, Absalom!, T.S. Eliot's The Waste Land, etc. This narrative perspective is entwined with the trauma discourse, and the article argues that some of the best-known Modernist techniques (like the stream of consciousness) are based on the Gothic model of spectral narration. In the works of the genre, ghosts are often portrayed as traumatized, incommunicative, and disoriented “shattered selves” eternally entrapped in the closed space of a single, repetitive traumatic memory. This also seems to be the case with many Modernist narrators. The article shows various ways this genre convention of the Gothic has been (re)used in Modernist storytelling. Furthermore, the “post-death narration” could also be interpreted as a “symptom” of extreme subjectivity and epistemic frustration (which are typical features of Modernist narration in general). It is also claimed that the narrative perspective of “posthumousness” was first employed in Melville's Moby-Dick and that Ishmael, the narrator of the novel, could be seen as the “prototype” of this kind of Modernist “post-death” narration.

Verification of GOTHIC Multivolume Containment Model during NPP Krško DBA LOCA

New containment multivolume model of NPP Krsko for GOTHIC code is developed. It is based on plant drawings and other available data. It is supported by developed SketchUp 3D containment model. The model is subdivided in volumes following physical boundaries and clearly defined flow paths. All important concrete heat structures are taken into account. Metal heat structures are based on plant’s SAR Chapter 6 licensing model. RCFC (Reactor Containment Fan Cooler) units are explicitly modelled as well as all main ventilation ducts. The model includes two trains of containment spray system. PARs (Passive Autocatalytic Recombiner) and PCFV (Passive Containment Filter Venting) filters added during plant safety upgrade project are part of the model too. It was intention to use model for both DBA (Design Basis Accident) and for DEC (Design Extended Conditions) and BDBA (Beyond Design Basis Accident) calculations. Based on the same discretization and data, and on experience acquired during GOTHIC model development and use, containment models for MELCOR and MAAP integral codes are developed too. As part of initial verification of the GOTHIC model containment DBA LOCA calculation is performed using SAR MER (Mass and Energy Release) data. The influence of different break positions on peak containment atmosphere pressure and temperature was studied. The results were compared against results obtained in single volume containment licensing model. Beside local effects due to different containment subdivision similar results are obtained when comparing containment dome from multivolume and the single volume in licensing model. Special attention was paid to distribution of water in lower part of the containment during recirculation phase. In this case much more valuable information are obtained in multivolume model with explicit volumes for main sump, recirculation sump and sump pit. Another point of interest was influence of containment spray duration on long term pressure and temperature behaviour. The intention was to study consistency of assumed different spray operation times used in safety analyses, EQ analyses and SAMGs and related consequences for plant operation during DBA LOCA.

AP1000 Passive Containment Cooling System study under LBLOCA conditions using the GOTHIC code

AP1000® Generation III+ reactor bases its safety concept on passive systems, differently from the previous Generation II reactors. This fact has led the approximations and methodologies previously used for modeling active safety systems to be reviewed and adapted to simulate the physics of passive systems. Diverse studies about the AP1000 containment have demonstrated the difficulty to correctly model the occurring phenomenology.In this paper, an integral AP1000 3D containment GOTHIC model is presented, including the Passive Containment Cooling System (PCCS). The model includes the compartments inside and outside the metallic containment liner that influence the thermal–hydraulic behavior. The model is tested against a Large Break Loss of Coolant Accident (LBLOCA) to assess its thermal–hydraulic performance, assuming a PCS tank malfunction, what is a conservative hypothesis. The pressure and temperature evolution predicted by the 3D containment model is analyzed and compared with a single node Lumped Parameters model, allowing to evaluate some preliminary benefits of 3D modeling for containment safety analysis.The 3D containment model allows to predict the thermal evolution in each containment compartment capturing the heterogeneity of this phenomenon, with higher resolution than the lumped parameters models traditionally used in this kind of analyses. It allows to observe the thermohydraulic conditions locally at any time during the transient.

Coupling Gothic and RELAP5 for Passive Containment Cooling Modeling

GOTHIC and RELAP5 have been coupled to model the containment and passive containment cooling system (PCCS) for the Korean advanced containment designs. In the coupled system, GOTHIC models the containment and the outer shell (mid tube wall to outside surface) of the PCCS heat exchanger tubes and RELAP5 models the inner shell (inside surface to mid tube wall) and the coolant loop to the external heat sink. The coupling approach leverages the modeling capabilities of RELAP5 for piping load analysis and the capabilities of GOTHIC for containment and heat/mass transfer with noncondensing gases. With the coupled model, it is possible to apply the thermal-hydraulic load analysis on the PCCS supply and return piping considering the containment conditions predicted by GOTHIC during a loss-of-coolant accident (LOCA). This paper describes the coupling approach, a coupling dynamic linked library for GOTHIC, modifications to RELAP5, and verification of the coupling. Last, demonstration results from a LOCA simulation with four PCCS trains is provided and the results of the GOTHIC/RELAP5–coupled model are compared to a GOTHIC-only result, where GOTHIC was used to model both the containment and the PCCS.

Faithful Crosses. On the Survival of an Early Type of Goldsmith’s Cross in Late Medieval Catalonia

Three silver crosses created in Catalonia in the fourteenth century - from Vilabertran, St Joan de les Abadesses, and Girona Cathedral - have an archaic design that differs from the Gothic models more common in the region and throughout Western Europe by that time. Recent research on these crosses, particularly on that from St Joan de les Abadesses (now in the Museu Episcopal de Vic), has yielded new findings that contribute to our understanding of this design’s final flourishing in the late Middle Ages. These three objects were the last examples created in Catalonia of an old type of multi-functional goldsmith’s cross. Crosses of this type were filled with relics that were not always evident to the faithful but that enhanced the ability of the objects’ being turned into ideal representations of the True Cross. This, in turn, imbued them with significance beyond sensory perception of their material properties.

Игровая историософия А. Иванова: насилие формы и реабилитация смысла (на материале романов «Псоглавцы» и «Пищеблок»)

The paper analyzes the specificity of Ivanov’s historiosophy in two novels, “Psoglavtsy” and “Pishcheblok,” which are particularly interesting in this sense since in terms of genre, they do not correspond to the scale of historical issues as much as possible. These novels use the Gothic genre model, preserving the specifics of artistic space and type of hero. However, the generic Gothic time is replaced by historical time, experienced personally and subjectively. Meanwhile, a specific feature of Gothic time is retained, such as repetition, replaying a crisis moment of the past until the balance is restored. The author refuses a vector image of national history, forcing historical time to repeat itself in a cycle that resembles not only literary Gothic but also a computer game. It is not a question of bad infinity, but a game repetition, eventually leading to the “passage” of a crisis section of history. Thus, the struggle against genre form rehabilitates the content of national history. This principle also defines the history concept as a whole: A. Ivanov tends to see the historical process as including both the aggression of “form” (empire, state power, fate) and the defense of “content” (humanity revealed in individual choice), which, being opposed, are equally necessary for each other. Not only does the method based on the struggle and mutual necessity of form and content shape historiosophy in A. Ivanov’s novels, but it also organizes their artistic world. Ivanov’s game historiosophy is thus opposed to a postmodern game tending to destruct form and meaning.

Benchmark of GOTHIC to EBR-II SHRT-17 and SHRT-45R Tests

GOTHIC™ has been used to simulate the Experimental Breeder Reactor–II (EBR-II) Shutdown Heat Removal Test 17 (SHRT-17) and Shutdown Heat Removal Test 45R (SHRT-45R), which correspond to protected and unprotected loss-of-flow events, respectively. GOTHIC is a versatile general-purpose, thermal-hydraulic software package that is a hybrid between traditional system thermal-hydraulic and computational fluid dynamics codes. It is a practical engineering tool that has been used for the design and licensing of existing plants, small modular reactors (SMRs), and next-generation plant designs. Historically, the software has been applied for containment analysis and operability assessments for light water reactors (LWRs), but the recent improvements included in GOTHIC 8.3(QA) allow for the software to be used to simulate advanced, non-LWR concepts currently being developed such as sodium, molten salt, lead, and gas–cooled designs. It will be demonstrated in this paper that GOTHIC includes both the required attributes to model EBR-II and the appropriate physics to accurately simulate the steady-state operating conditions as well as SHRT-17 and SHRT-45R. The GOTHIC model of EBR-II was developed using only publicly available information. The nodalization was selected not only to capture the important phenomena but also to remain computationally efficient. The GOTHIC results show good agreement in both magnitude and trend with the experimental data. Differences are within the bounds of experimental uncertainty and required engineering assumptions applied in the model to fill in gaps in information, particularly for the various leakage paths that existed throughout the primary side of EBR-II, and were not well characterized during the tests.

Experimental and computational analysis of a passive containment cooling system with closed-loop heat pipe technology

In this paper, a conceptual design of Passive Containment Cooling System with Closed-Loop Heat Pipe Technology (PCSHP) is studied using both experimental and computational methods. By studying on the thermal-hydraulic parameters in system running, such as temperature, pressure and flow rate, the paper mainly focuses on the start-up characteristics, the steady-state operating characteristics, the heat transfer capacity and the natural circulation capacity of the system. Hence, the principle experiment and GOTHIC simulation were carried out under start-up conditions, steady-state conditions and decay heat simulation conditions. The applicability and conservatism of the GOTHIC model is evaluated by comparing the simulating results with the experimental results. The rationality of the system design is validated by both the principle experiment and GOTHIC simulation. It is preliminarily judged that the heat pipe technology is feasible to apply to the Passive Containment Cooling System (PCCS) of nuclear power plant.

Steam condensation simulation in a scaled IRWST-ADS simulator with GOTHIC 8.1

The AP1000® advanced reactor passive safety systems are based on natural phenomena to ensure the containment integrity during an accident. One of the most important passive systems is the Passive Core Cooling System (PXS) which includes the In-containment Refueling Water Storage Tank (IRWST), a pool that serves as a heat sink for the Passive Residual Heat Removal Heat Exchanger (PRHR) and the Automatic Depressurization System (ADS).The thermal-hydraulic behavior of the pool is quite complex under accidental conditions: the pool receives steam at high velocity and temperature from the Reactor Cooling System (RCS), the pool is the heat sink of the PRHR, and eventually, it is the source for the low pressure safety injection. In order to study the behavior of the AP1000 IRWST during a steam discharge from the ADS at different stages of a SBLOCA, an experimental test rig was constructed in cooperation with the Technical University of Munich (TUM). The results obtained in the IRWST-ADS experiment were used to test the capability of GOTHIC 8.1 to simulate the phenomena observed experiments such as thermal stratification, direct contact condensation, and flashing. The GOTHIC model is based on two control volumes, one represents the channel test and the other the laboratory room. These control volumes are connected with a 3D-Connector between each other and with flow-paths to the boundary conditions. Pressure boundary conditions has been applied to the laboratory room control volume to maintain a constant pressure and temperature. Simulations were able to reproduce major occurring phenomena. Thermal stratification and flashing were predicted plausibly, however the direct contact condensation of steam and void fraction distribution are not perfectly simulated probably because of the selected mesh size. A sensitivity analysis has been conducted to the discretization scheme, the turbulence model, and the heat transfer correlation in order to test their effect upon GOTHIC model simulation.

Safe reactor depressurization windows for BWR Mark I Station Blackout accident management strategy

In order to evaluate the effectiveness of reactor depressurization within accident mitigation strategy and how to avoid core damage during Station Black-Out accident in a BWR Mark I plant, a GOTHIC model has been developed to support characterization of reactor safety systems performance. The GOTHIC model provides seamless coupled simulations of the reactor coolant system and the containment system. In this study, the time intervals (also called “safe reactor depressurization windows”) to initiate the reactor depressurization in order to optimize the early cooling strategy by injecting fire water and avoid clad failure are studied based on the decay heat removal capability of the reactor vessel coolant. This concept is instructive for the operation of the safety systems during the SBO accident mitigation. Sensitivity studies of several key parameters like reactor power, mass flow rates through RCIC system and fire water injection, and full open discharge coefficient of SRVs are performed to evaluate their impact on the safe reactor depressurization windows.

The integrity of NSSS and containment during extended station blackout for Kuosheng BWR plant

Abstract The Fukushima Daiichi accident occurring on March 11, 2011, reveals that Station Blackout (SBO) may last longer than 8 h. However, the original design may not have sufficient capacity to cope with a SBO for more than 8 h. In view of this, Taiwan Power Company has initiated several enhancements to mitigate the severity of the extended SBO. Based on the improved plant configuration, a SBO coping analysis is performed in this study to assess whether the Kuosheng BWR plant has sufficient capability to cope with SBO for 24 h with respect to maintaining the integrity of the reactor core and containment. The analyses in the Nuclear Steam Supply System (NSSS) and the containment are based on the RETRAN-3D and GOTHIC models, respectively. The flow conditions calculated by RETRAN-3D during the event are retrieved and input to the GOTHIC containment model to determine the containment pressure and temperature response. These boundary conditions include SRV flow rate, SRV flow enthalpy, and total reactor coolant system leakage flow rate.

Direct torus venting analysis for Chinshan BWR-4 plant with MARK-I containment

The Chinshan plant, owned by Taiwan Power Company, has twin units of BWR-4 reactor and MARK-I containment. Both units have been operating at rated core thermal power of 1840MWt. The existing Direct Torus Venting System (DTVS) is the main system used for venting the containment during the extended station blackout event. The purpose of this paper is to study the effects of the DTVS venting on the response of the containment pressure and temperature. The reactor is depressurized by manually opening the safety relief valves (SRVs) during the SBO, which causes the mass and energy to be discharged into and heat up the suppression pool. The RETRAN model is used to calculate the Nuclear Steam Supply System (NSSS) response and generate the SRV blowdown conditions, including SRV pressure, enthalpy, and mass flow rate. These conditions are then used as the time-dependent boundary conditions for the GOTHIC code to calculate the containment pressure and temperature response. The DTVS model is established in the GOTHIC model based on the venting size, venting piping loss, venting initiation time, and venting source. The lumped volume model, 1-D coarse-mesh model, and 3-D coarse-mesh model are considered in the torus volume. The calculation is first done without DTVS venting to establish a reference basis. Then a case with DTVS available is performed. Comparison of the two cases shows that the existing DTVS design is effective in mitigating the severity of the containment pressure and temperature transients. The results also show that the 1-D coarse-mesh model may not be appropriate since a physically unrealistic thermal stratification is observed in the suppression pool liquid volume. A fine-mesh 3-D model for the torus is identified as an essential part to be studied further.

Architecture and the arts in Catalonia during the Renaissance

This is an overview of the process of transformation of the architecture, sculpture and painting of Catalonia during the Renaissance. It attempts to reconstruct the fundamental era of changes when the late Gothic models were replaced by the new Renaissance paradigm gestated in Italy, thus ushering in the modern cycle of arts in the country. Despite the relative dearth of a Catalan historiographic tradition that studies and explains the cultural heritage from this period – which was decimated by the massive destruction in the 19th and 20th centuries, which particularly targeted religious works – we begin to trace the major outlines of the process of assimilating the Renaissance which got underway in the 16th century and did not culminate until well into the 17th century. What emerges is the notable volume of artistic output undertaken, the main agents and factors in the transformation, the slow yet steady pace of the incorporation of changes, the long phase of hybridisation and the uneven acceptance of Renaissance features depending on the different parameters of architecture or figurative arts considered.

Architecture and the arts in Catalonia during the Renaissance

This is an overview of the process of transformation of the architecture, sculpture and painting of Catalonia during the Renaissance. It attempts to reconstruct the fundamental era of changes when the late Gothic models were replaced by the new Renaissance paradigm gestated in Italy, thus ushering in the modern cycle of arts in the country. Despite the relative dearth of a Catalan historiographic tradition that studies and explains the cultural heritage from this period – which was decimated by the massive destruction in the 19th and 20th centuries, which particularly targeted religious works – we begin to trace the major outlines of the process of assimilating the Renaissance which got underway in the 16th century and did not culminate until well into the 17th century. What emerges is the notable volume of artistic output undertaken, the main agents and factors in the transformation, the slow yet steady pace of the incorporation of changes, the long phase of hybridisation and the uneven acceptance of Renaissance features depending on the different parameters of architecture or figurative arts considered.

Proposed methodology for Passive Autocatalytic Recombiner sizing and location for a BWR Mark-III reactor containment building

The Stress Tests accomplished by the European nuclear plants assume to be a complementary and comprehensive review of the safety of nuclear facilities, taking into account the events occurred in Fukushima Daiichi. The analysis of Passive Autocatalytic Recombiners (PARs) installation in Cofrentes NPP (BWR Mark III, 1092 MWe) was a requirement emerged from those tests and developed by Iberdrola Engineering and Construction jointly with Universidad Politécnica de Madrid (UPM). The study established a methodology for location and number of PARs for being installed to minimize the risk arising from an hydrogen release and its distribution in containment building during a severe accident (SA). In this paper, the implementation of this methodology was deeply analyzed for Cofrentes NPP.The proposed methodology presented herein for PARs installation analysis is divided in four steps: identification of the most limiting scenarios to be simulated with a severe accident code (MAAP4) in order to obtain mass and energy sources (step 1); hydrogen distribution analysis in containment with a 3D containment code (GOTHIC 8.0) (step 2 and 3); and PAR sizing and location analysis (step 4). The most limiting scenarios chosen for a BWR were: Station Blackout (SBO); Total Loss of Feed Water (TLOFW); and Loss of Coolant Accident (LOCA). Several sensitivity analyzes of different PAR sizes and configurations were accomplished, and the most suitable PARs configuration was determined. This optimal configuration consisted in a total of 53 PARs: 47 units placed inside the containment and 6 units in the drywell. For data analysis, an in-house code was developed, providing combustion and deflagration data in a clear and accurate way, showing the combustion windows and their span.The proposed methodology was established as accurate enough for analysing PARs installation within containment applied to a BWR Mark III. The fact of having a very detailed 3D GOTHIC model allowed creating a strategy of implementation based on the preferred hydrogen pathways and areas of accumulation.

Alternative cooling water flow path for RHR heat exchanger and its effect on containment response during extended station blackout for Chinshan BWR-4 plant

The extended Station Blackout (SBO) of 24h has been analyzed with respect to the containment response, in particular the suppression pool temperature response, for the Chinshan BWR-4 plant of MARK-I containment. The Chinshan plant, owned by Taiwan Power Company, has twin units with rated core thermal power of 1840MW each. The analysis is aimed at determining the required alternative cooling water flow capacity for the residual heat removal (RHR) heat exchanger when its tube-side sea water cooling flow path is blocked, due to some reason such as earthquake or tsunami, and is switched to the alternative raw water source. Energy will be dissipated to the suppression pool through safety relief valves (SRVs) of the main steam lines during SBO. The RETRAN model is used to calculate the Nuclear Steam Supply System (NSSS) response and generate the SRV blowdown conditions, including SRV pressure, enthalpy, and mass flow rate. These conditions are then used as the time-dependent boundary conditions for the GOTHIC code to calculate the containment pressure and temperature response. The shaft seals of the two recirculation pumps are conservatively assumed to fail due to loss of seal cooling and a total leakage flow rate of 36gpm to the drywell is included in the GOTHIC model. Based on the given SRV blowdown conditions, the GOTHIC containment calculation is performed several times, through the adjustment of the heat transfer rate of the RHR heat exchanger, until the criterion that the maximum suppression pool temperature is maintained below 200°F is met. This heat transfer rate in conjunction with the RHR heat exchanger UA values (overall heat transfer coefficient times heat transfer area) are used to iteratively determine the heat exchanger effectiveness and the corresponding raw water flow rate. The base case considered in the study assumes that the reactor is first depressurized to ∼800psia at t=1h, and is then further depressurized to ∼300psia at t=5h. The 5th diesel generator and the gas-turbine generator are assumed available at t=5h and are used to power the RHR pump for suppression pool cooling. The analysis results for this base case show that a minimum flow rate of 1346.4gpm is required for the raw water source to meet the criterion that the maximum suppression pool temperature remains below 200°F during the SBO of 24h. Sensitivity studies are performed to investigate the effect of depressurization and the timing for initiating the depressurization. Although it is well recognized that depressurization is beneficial for the later accident mitigation, e.g., injecting of low-pressure fire water to cool down the reactor, the results show that it needs more cooling water flow rate for the RHR heat exchanger to meet the 200°F criterion. Also, the timing to initiate the depressurization may have a significant effect on the required cooling water flow capacity.

Development of a hydrogen diffusion gothic model of MARK III-containment

Abstract The accident that occurred at the Fukushima Daiichi Nuclear Power Plant is a reminder of the danger of hydrogen explosion within a reactor building. Sufficiently high hydrogen concentration may cause an explosion that could damage the structure, resulting in the release of radioisotopes into the environment. In the first part of this study, a gas diffusion experiment was performed, in which helium was used as the working fluid. An analytical model was also developed using the GOTHIC code and the model predictions of the helium distribution were found to be in good agreement with the experimentally measured data. In the second part of the study, a model of the Mark III containment of the Kuosheng Plant in Taiwan was developed, and was applied to a long-term station blackout (SBO) accident similar to that of the Fukushima plant. The hydrogen generation was calculated using the Modular Accident Analysis Program and was used as the boundary condition for the GOTHIC containment model. The simulation results revealed that the hydrogen concentration at the first floor of the wetwell in the containment reached 4% 9.7 h after the accident. This indicated the possibility of dangerous conditions inside the containment. Although active hydrogen ignitors are already installed in the Kuosheng plant, the findings of this study indicate that it may be necessary to add passive recombiners to prolong an SBO event.

BWR MARK I pressure suppression pool mixing and stratification analysis using GOTHIC lumped parameter modeling methodology

As a part of the GOTHIC (GOTHIC incorporates technology developed for the electric power industry under the sponsorship of EPRI.) Fukushima Technical Evaluation project (EPRI, 2014a, b, 2015), GOTHIC (EPRI, 2014c) has been benchmarked against test data for pool stratification (EPRI, 2014a, b, Ozdemir and George, 2013). These tests confirmed GOTHIC’s ability to simulate pool mixing and stratification under a variety of anticipated suppression pool operating conditions. The multidimensional modeling requires long simulation times for events that may occur over a period of hours or days. For these scenarios a lumped model of the pressure suppression chamber is desirable to maintain reasonable simulation times. However, a lumped model for the pool is not able to predict the effects of pool stratification that can influence the overall containment response. The main objective of this work is on the development of a correlation that can be used to estimate pool mixing and stratification effects in a lumped modeling approach. A simplified lumped GOTHIC model that includes a two zone model for the suppression pool with controlled circulation between the upper and lower zones was constructed. A pump and associated flow connections are included to provide mixing between the upper and lower pool volumes. Using numerically generated data from a multidimensional GOTHIC model for the suppression pool, a correlation was developed for the mixing rate between the upper and lower pool volumes in a two-zone, lumped model. The mixing rate depends on the pool subcooling, the steam injection rate and the injection depth.