CSNI0003 LOBI/B-R1M.

1. NAME OR DESIGNATION:  LOBI/B-R1M.

3. DESCRIPTION OF TEST FACILITY

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 the pump speeds, since the two pumps are identical. Heat is removed from the  steam generators by a secondary system.  ECC water can be supplied from two accumulators, one for each loop. Cold or hot leg as well as combined injection can be simulated.
  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

The test B-R1M is one of the LOBI experimental program B which was performed in the LOBI test facility.  This test belongs to the interim test program which comprises a total of five large cold leg break tests.
   In the B-R1M a single ended cold leg break between the primary pump and the pressure vessel, with ECC water injection into the intact cold loop leg only, was simulated.  The double ended rupture device was used.  The flap on the pump side remained closed and the flap on the vessel side was opened. The isolation valve between the  two flaps was maintained in the open position.  In this test the pressurizer was connected to the intact loop.
Test B-R1M represents the smallest large-break test of a series of four which were envisaged to cover the large break spectrum and thus substantiate the influence of break size on blowdown in the case of cold leg break and with intact loop cold leg ECC water injection only.  In these tests the downcomer gap width was 50 mm.

5. EXPERIMENTAL LIMITATIONS OR SHORTCOMINGS

LOBI experiments cover only the blowdown phase of a transient.  The available downcomer gaps result in either unrealistic core flows or too large a hot-wall effect and unrealistic ECC delivery.

6. PHENOMENA TESTED:  Phase separation, 1- and 2-phase pump behavior.

7. SPECIAL FEATURES OF EXPERIMENT

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

8. COUNTERPART EXPERIMENTS:  Semiscale.

- C. Addabbo:
LOBI and Semiscale Counterpart Tests, Preliminary Comparison Analysis of LOBI
MOD1 Test B-R1M and SEMISCALE MOD2A Test S-1B-3
ISPRA Technical Note No. I.06.01.83.17, January 1983
- E. Ohlmer, J. Sanders:
Experimental Data Report on LOBI Test B-R1M
ISPRA LEC 82-08, Communication No. 3816, April 1982
- C. Addabbo, G. De Santi, L. Piplies:
Quick Look Report on LOBI Test B-R1M
ISPRA LQC 82-08, Communication No. 3815, March 1982
- 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:  B-R1M

15. ESTABLISHMENT

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

CCVM data        mag tapeLOBI-MOD1 B-R1M data     4.0 MB            CVMTP