Profile SFR-52

SWAT

JAPAN

GENERAL INFORMATION NAME OF THE FACILITY

SWAT

ACRONYM Sodium-WAter reaction Test facility COOLANT(S) OF THE FACILITY

Sodium

LOCATION (address): Oarai Research and Development Institute, Japan Atomic Energy Agency (JAEA), 4002 Narita, Oarai-machi, Ibaraki-ken, 311-1393, Japan

OPERATOR JAEA CONTACT PERSON (name, address, institute, function, telephone, email):

Shuji OHNO, Reactor Systems Design Department Sector of Fast Reactor and Advanced Reactor Research and Development Japan Atomic Energy Agency (JAEA) 4002 Narita, Oarai-machi, Ibaraki-ken, 311-1393, Japan Tel: +81 29 267 4141, email: ohno.shuji@jaea.go.jp

STATUS OF THE FACILITY

In operation

Start of operation (date): TS #1 (SWAT-3R): 2001

MAIN RESEARCH FIELD(S)

☐ Zero power facility for V&V and licensing purposes ☒ Design Basis Accidents (DBA) and Design Extended

Conditions (DEC) ☐ Thermal-hydraulics ☒ Coolant chemistry ☒ Materials ☒ Systems and components ☐ Instrumentation & ISI&R

TECHNICAL DESCRIPTION

Description of the facility SWAT-3R is a test facility to evaluate the tube failure/pressure propagation caused by water leak from heat transfer tube in steam generator (SG) of sodium-cooled fast reactor. This facility simulates the secondary cooling system and reaction product release system in real

plant, and consists of sodium system, water/steam system, release system and gas supply system, and so on. SWAT-3R possesses 15tons of sodium and reaction vessel (simulated SG) of 1.3m inside diameter, 7.7m in height. Synthesis validation data such as tube failure propagation are obtained under from intermediate to large water leak rate conditions. Each system and component in SWAT-3R are shown in the following. Sodium main circulation system consists of reaction vessel, electromagnetic pump, sodium tank, sodium heater, piping and valves, etc. Test section is fabricated to fit the test objectives and installed in RV. Sodium purification system consists of cold trap, economizer, plugging meter, piping and valves, etc. Reaction product can be removed in cold trap, and purity of sodium can be elevated. Heat is exchanged by the temperature difference between inlet and outlet of cold trap. Sodium charge/drain system consists of dump tank (DT), piping and valves, etc. DT serves as the pathway of release system at the time of sodium-water reaction test, reaction products are separated crudely in DT. Gas supply system consists of argon/nitrogen gas cylinders, vapour trap, vacuum pump, air compressor, piping and valves, etc. Reaction product release system consists of reaction product storage tank (RT), hydrogen gas discharge piping, reaction product drainage piping and valves, etc. Rupture disc is burst and pressure in RV is maintained lower. Reaction products due to sodium-water reaction are separated by liquid (sodium compound) and hydrogen gas in RT, hydrogen gas is discharged to the atmosphere while burning. Water/steam system is classified roughly into two systems and consists of water heater, water feeding header, steam catch tank, piping and valves. One system is used for water/steam injection as initial leak, the other is used to cool inside adjacent tubes. Sodium cleaning device is used for stabilization treatment of sodium which attached to a structure due to humid carbon dioxide. In the SWAT-3R tests, test section fabricated to fit test objectives is mounted into RV. And sodium system is vacuumed and is substituted for argon gas. In test operation, sodium system is heated and sodium in DT is transferred to sodium system. Then sodium and water/steam system are elevated up to test conditions (equivalent to operation conditions of real SG plant). After test condition is regulated, injection valve is opened and high temperature and high pressure water/steam is lead into RV. Sodium-water reaction data are measured synchronously by data logger at a sampling rate of 50 ms. Acceptance of radioactive material No

Scheme/diagram

FIG. 1. Flow diagram of Large-scale Sodium-water reaction test facility (SWAT-3R)

3D drawing/photo

FIG. 2. Full view of SWAT-3R test facility

FIG. 3. Test section (inner structure of RV) of SWAT-3R

Parameters table Coolant inventory TS #1: 15 ton of sodium Power TS #1: 1,200 kW (1.2 MW) Test sections

TS #1 (SWAT-3R)

Characteristic dimensions (Reaction vessel (simulated SG)) TS #1: Inner diameter 1.3 m, Height 7.7 m Static/dynamic experiment Dynamic Temperature range in the test section (Delta T) Maximum temperature: About 1200 °C (About the difference of 700 K) Operating pressure and design pressure TS #1: Operating Pressure 0.1 MPa (gauge), Design Pressure 1.96 MPa(gauge) in sodium side, Operating Pressure 19.6 MPa (gauge), Design Pressure 24 MPa(gauge) in water side Flow range (mass, velocity, etc.) TS #1: 2.3 m3/min (sodium)

Coolant chemistry measurement and control (active or not, measured parameters)

None.

Instrumentation Thermocouples, Pressure transducers, Electromagnetic flow meter, Differential pressure type flowmeter, Void sensors, Level gauge, Acoustic sensors, Rupture discs.

COMPLETED EXPERIMENTAL CAMPAIGNS: MAIN RESULTS AND ACHIEVEMENTS

In SWAT-3R, a first campaign (three tests) was carried out to confirm the wastage environment around target tube under intermediate water leak condition of 1 kg/s for JSFR SG. The surface temperature on wastage tube was estimated by metallographic observation, it was confirmed that wastage rate and surface temperature in case of superheat steam injection was higher than those in case of saturated steam. A second campaign (three tests) was carried out to confirm the tube failure propagation behaviour in straight tube type SG. Temperature distribution, heat-affected temperature of tube and failure time were measured in a partially simulated tube bundle of large scale SG.

PLANNED EXPERIMENTS (including time schedule)

No experimental program is planned in 2019 and 2020.

TRAINING ACTIVITIES Training activities have been carried out before the operation of experimental campaign based on a quality management system of JAEA.

REFERENCES (specification of availability and language) • M. Nishimura, K. Shimoyama, A. Kurihara and H. Seino, “Sodium-water reaction test to

confirm thermal influence on heat transfer tubes,” JNC-TN9400 2003-014. (Japanese)

• S. Futagami, A. Kurihara and T. Yatabe, “Thermal-Hydraulic Characteristics of Sodium-Water Reaction Jet - Effect of Cover Gas Pressure on Temperature Distribution -,” JNC-TN9400 2005-042. (Japanese)

• K. Shimoyama, “Wastage-Resistant Characteristics of 12Cr Steel Tube Material -Small Leak Sodium-Water Reaction Test-,” JNC-TN9410 2004-009. (Japanese)

• A. Kurihara, S. Kikuchi, R. Umeda and H. Ohshima, “The Effect of Flow-Accelerated Corrosion with High-Temperature Sodium Hydroxide on Tube Target-Wastage Caused in Steam Generator of Sodium-Cooled Fast Reactor,” Journal of Japan Society of Mechanical Engineers-B, Vol. 79, No. 799, 2013, pp. 267-270. (Japanese)

• A. Kurihara, R. Umeda, K. Shimoyama, Y. Abe, S. Kikuchi and H. Ohshima, “Heat Transfer Characteristics of Sodium-Water Reaction Jet around a Tube in Steam Generator of Sodium-Cooled Fast Reactor,” Journal of Japan Society of Mechanical Engineers-B, Vol. 79, No. 808, 2013, pp. 2640-2644. (Japanese)

• S. Kikuchi, H. Ohshima et al, "Theoretical Study of Sodium-Water Surface Reaction Mechanism," Journal of Power and Energy Systems, Vol.6, No.2 (2012). (En)

• S. KIKUCHI, H. SEINO, A. KURIHARA and H. OHSHIMA, "Kinetic Study of Sodium-Water Surface Reaction by Differential Thermal Analysis," Journal of Power and Energy Systems, Vol.7, No.2 (2013). (En)