Bologna on 28 May 2008 – IP EUROTRANS WP1.5 1

IE - Institute for EnergyPetten - The Netherlands

http://ie.jrc.ec.europa.eu/

http://www.jrc.ec.europa.eu/

Joint Research Centre (JRC)

SGTR and SGTL

Bologna on 28 May 2008 – IP EUROTRANS WP1.5 2

Overview

• Background to SGTR and SGTL

• Present status of cooperation on SGTL between KTH and JRC

• SGTR experiments to be executed at FZK on behalf of JRC

• Conclusions

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Pool design and SGTR, SGTL

SGTR SGTL

15..25 MPa, 330..500 oC

0.3 MPa, 400..500 oC

Steam Generator Tube

Rupture (SGTR)

SGTR at PWR ~103–104 liter/hour

Steam Generator Tube

Leakage (SGTL)

SGTL Rate: 10 - 103 liter/day

Leakage less than 1 liter/day – allowed in normal operation of PWRFrom P. Kudinov

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Liquid fraction

Beznosov et al (2005)

A.V. Beznosov, ”Experimental Studies of the Characteristics of Conatct Heat Exchange between lead Coolant and the Working Body”, Atomic Energy, 98(3), 2005

“a steam–water mixture, and 100–350°C, 1–25 MPa steam were bubbled through 0.6–2 mm in diameter openings (tube 14x2 mm), under a layer of lead ranging in thickness from 100 to 3000 mm, at temperatures 350–600°C”

Water injection (at 30 MPa, 335 oC) into lead at 0.8 MPa

liquid water

No explosion reported.Limited expansion.

From P. Kudinov

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Size distributions of water/steam droplets

Beznosov et al, 2005

From P. Kudinov

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Life time of small droplet

Guido Bleiker and Eckehard Specht Film evaporation of drops of different shape above a horizontal plate International Journal of Thermal Sciences, Volume 46, Issue 9, September 2007, Pages 835-841

Time scale is ~10s of seconds for droplets ~1mm in diameter

From P. Kudinov

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Vapor bubbles formation

Evaporation of water droplet in a bubble will lead to growth of bubble diameter.

Big bubbles most likely will not be stable due to high We number and high turbulence level.

As a result we will have larger number of middle size bubbles up to 10 mm in diameter.

From P. Kudinov

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Vapor bubbles formation and transport phenomena

Terminal speed of rising bubbles with dmax~10mm is ~0.2-0.3 m/s

Importance of resolution of 3D structure of the coolant flow for reliable prediction of void flux into the core

Terminal velocity

0.00

0.10

0.20

0.30

0.40

0.50

0.60

0.70

0.80

0.1 1 10 100d, mm

m/s

Jamialahmadi

Mendelson

Lehrer

Mendelson:

Lehrer:From P. Kudinov

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Stream lines and flow field

Stream lines during normal operation

Flow field during normal operation

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Following calculation step

Small leakage is assumed in this study.

Next step will be to introduce individual steam bubbles at different locations in the HX. These bubbles will be followed along their trajectories.

Different sizes of bubbles will be studied.

The probability that bubbles reach the core will be estimated.

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SGTR experiment

The bunker (at FZK funded by JRC) where the experiment be performed

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Experimental facility

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Experiments to be performed

1. Steam of 200 bar pressure released into water simulating break of 8 pipes – will be performed during summer of 2008

2. Injection of 3 liters of superheated steam (25 bar, 160C) into Pb of 340C.

3. Injection of 3 liters supercritical steam (240 bar, 400C into Pb of 480C. Simulating break of 8 pipes of the EFIT or ELSY design.

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Summary

Cooperation between KTH and JRC concerning studies on small leakages. Results from this study expect this autumn.

SGTR experiments will be performed at FZK. The first one will be performed this summer.