CSNI0037 LOBI/A2-77A.

1. NAME OR DESIGNATION:  LOBI/A2-77A

3. DESCRIPTION OF TEST FACILITY

The LOBI-MOD2 test facility is a high pressure integral system blowdown refill test facility designed, constructed and operated at the Joint Research Centre of the European Communities, Ispra Establishment, Italy. It represents and extensive modification of the original MOD1 configuration and was put into operation after June 1982.
   The LOBI facility is a 1/700 scale model of a four loop PWR and has two primary loops, the intact loop representing three loops and the broken loop representing one loop of a four-loop PWR.  The reactor pressure vessel model contains an electrically heated rod-bundle with 64 rods and a heated length of 3.9 m. The nominal heating power is 5.3 MW.  The downcomer is of annular shape.  An upper head simulator is connected to the vessel. Each of the two primary loops contains a pump and a steam generator. The different mass flows in the loops are established by different pump speeds, since the two pumps are identical. ECC water can be supplied from two accumulators, one for each loop.  Cold or hot leg as well as combined injection can be simulated. Heat is removed from the steam  generators by a secondary system.
In the MOD2 configuration, emergency core cooling (ECC) water can be supplied by the high pressure injection system (HPIS) and by the accumulator injection system (AIS).
  The LOBI test facility is the only high pressure integral test facility within the European Communities (1982), built and operated in the Joint Research Centre, Ispra, ITALY. In the LOBI experiments  the thermal-hydraulic behavior of the facility during a transient, caused by a simulated loss of coolant accident (LOCA), is investigated to provide an experimental basis for analytical model development and code verification.

4. DESCRIPTION OF TEST

Test A2-77A represents one of the first experiments of the LOBI-MOD2 Small Leak Programme, which was started in April 1984. It is designed to establish the natural
circulation behaviour of the LOBI-MOD2 primary loop under single phase and two phase flow conditions without rupture in the primary loop.

5. RESTRICTIONS ON THE COMPLEXITY OF THE PROBLEM: EXPERIMENTAL LIMITATIONS OR SHORTCOMINGS

6. PHENOMENA TESTED

Natural circulation in 1- and 2-phase flow; asymmetric loop behaviour; phase separation; ECC mixing and condensation; heat transfer; 1- and 2-phase pump behaviour.

7. SPECIAL FEATURES OF EXPERIMENT

LOBI's large size and full height components are considered an advantage.

8. COUNTERPART EXPERIMENTS:  Semiscale.

- G. De Santi and G. Leva:
Quick Look Report on LOBI Test A2-77A
ISPRA LQC 85-32 Communication No. 4029, December 1985
- E. Ohlmer and J. Sanders:
Experimental Data Report on LOBI Test A2-77A
ISPRA LEC 85-33, Communication No. 4024, April 1985
- W. Kolar and W. Brewka:
LOBI Experimental Data Tape - Format Description
Technical Note No.I.06.C1.85.49 (May 1985)
- LOBI Project - RELAP5 Base Input Data for LOBI-MOD2
LPC 85-18 (February 1985)

11. TEST DESIGNATION:  A2-77

15. ESTABLISHMENT

        Commission of the European Communities
        Joint Research Centre
        Ispra Establishment
        I-21020 Ispra
        ITALY

CCVM data        mag tapeNATURAL CIRCULATION AT 90   6,006Kbytes    CVMTP
CCVM data        mag tapeNATURAL CIRCULATION AT 75   5,961Kbytes    CVMTP