Role of operating parameters in improving stability of once through steam generator used in SFR. (May 2021)

• Record Type: Journal Article
• Authors: Pathak, S.P.; Velusamy, K.
• Is Part Of: Annals of nuclear energy. Volume 154(2021)
• Publication Date: 2021-05
• Subjects: Sodium cooled fast reactor -- Steam generator -- Stable operating regime -- Operating parameters -- Experiments; Nuclear energy -- Periodicals; Nuclear engineering -- Periodicals; 621.4805
• DOI: 10.1016/j.anucene.2020.108084
• Languages: English
• ISSNs: 0306-4549

Abstract

Highlights: We develop a thermal hydraulic model for sodium heated steam generators. We validate model by conducting experiments on a 5.5 MW capacity steam generator. Flow instability is observed in the steam generator at 20% load condition. Various options to improve steam generator stability are investigated. We establish that stable regime can be widened by reducing sodium flow-rate. Abstract: Once through type steam generators used in Sodium cooled Fast Reactors (SFR) are prone to flow instability. Operating parameters of the steam generators play vital role in defining a stable operating regime. Towards understanding this, a thermal hydraulic model is developed. The developed model is validated by performing experiments on a 19-tube model of straight vertical steam generator of 5.5 MW capacity. Flow instability is observed at 20% load conditions and the correlation developed by France et al. (1986) for predicting dynamic stability is validated. Various options for improving the stability, including increasing single-phase water flow resistance are investigated. It is found that by tweaking the operating parameters, viz., reducing sodium flow rate or increasing steam-side pressure, the stable operating regime can be widened, without increasing the water-side orifice pressure drop. This study is directed towards finalizing low power operating strategy of future Indian experimental fast reactor, FBTR-2.