Development of sodium leak detectors for PFBR

• Published in: Nuclear engineering and design Vol. 249; pp. 419 - 431
• Main Authors: Sylvia, J.I., Rao, P. Vijayamohana, Babu, B., Madhusoodanan, K., Rajan, K.K.
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 01.08.2012; Elsevier
• Subjects: Applied sciences; Controled nuclear fusion plants; Detectors; Discs; Disks; Energy; Energy. Thermal use of fuels; Exact sciences and technology; Fission nuclear power plants; Fuels; Installations for energy generation and conversion: thermal and electrical energy; Instrumentation; Leaks; Nuclear engineering; Nuclear fuels; Nuclear reactor components; Sodium; Prototype; Hydrogen; Rupture; Reactor vessel; High temperature; Leak detection; Pressure; Steam generator; Nuclear reactor; Sodium; Fast breeder; Fast reactor; Safety
• ISSN: 0029-5493; 1872-759X
• DOI: 10.1016/j.nucengdes.2012.04.010

► Sodium leak detection system developed for PFBR using diverse principle. ► Miniature, remotely locatable diverse leak detector developed for Main Vessel. ► Mutual inductance type leak detectors designed and adapted for different locations. ► Sodium Ionisation detectors used for area monitoring. ► Crosswire type leak detector designed, developed and tested. The 500MWe Prototype Fast Breeder Reactor (PFBR) is under advanced stage of construction at Kalpakkam near Chennai in India. The wide and high operating temperature, highly chemically active nature of sodium and its reaction with air make the sodium instrumentation complex over the conventional instrumentation. Over the years, traditional instruments such as wire type leak detectors, spark plug type leak detectors were developed and used in different sodium systems. The redundant and diverse leak detection method calls for development of special instrumentation for sodium systems which include sodium ionization (leak) detector for detecting minute sodium leak in addition to those systems based on mutual inductance principle. For detection of sodium leak from reactor Main Vessel (MV), diverse methods are used such as miniature, remotely locatable, Mutual Inductance type Leak Detector(MILD) and specially modified spark plug type leak detector. The design of MILD is suitably modified for detecting leak in double wall pipes and Diverse Safety Rod drive Mechanism (DSRDM). Steam/water leak in steam generator produces hydrogen and leads to high pressure and temperature in the system. Rupture disc is used as a safety device which punctures itself due to sudden pressure rise. To detect the discharge of sodium and its reaction products at the downstream of the rupture disc due to bursting of the rupture disc, cross wire type leak detector has been designed, developed and tested. The selection of the leak detection system depends on the location where leak has to be detected. This paper describes the recent developments carried out in leak detector systems to meet the challenges involved in developing robust sensors for PFBR including miniaturization of leak detectors and the ability to locate or withdraw them remotely through a long guide tube with complex profile.