1. NAME AND TITLE

BLOCKAGE2.5r: Code System to Calculate Potential Plugging of Emergency Core Cooling Suction Strainers by Debris in a BWR.

2. CONTRIBUTORS

Science and Engineering Associates, Inc., Albuquerque, NM and Software Edges, Inc., Riverwoods, Illinois through the Energy Science and Technology Software Center, Oak Ridge, TN.

3. CODING LANGUAGE AND COMPUTER

Lahey FORTRAN 90 and Microsoft Visual C++ ver 1.51; IBM PC 386 (P00377IBMPC00).

4. NATURE OF PROBLEM SOLVED

BLOCKAGEV2.5r is an integrated calculational method with graphic user's interface for evaluating the potential for loss of emergency core cooling systems pump net positive suction head margin due to insulation/other debris layer buildup on suction strainers following a postulated loss of coolant accident in boiling water reactors. Blockage incorporates the results of multi-year NRC sponsored research documented in NUREG/CR-6224. It also provides a framework into which the user can input plant-specific/insulation-specific information for performing analysis in accordance with Regulatory Guide 1.82, Rev. 2.

5. METHOD OF SOLUTION

Modularized approach for parametrically treating different phenomena: debris generation, debris transport, debris cake buildup, and head loss.

6. RESTRICTIONS OR LIMITATIONS

Relies heavily on user specified information and no small LOCA models.

7. TYPICAL RUNNING TIME

8. COMPUTER HARDWARE REQUIREMENTS

PC with 80386 processor, 4 MB of Ram, 2 MB of free hard disk space, monitor capable of displaying 16 colors at a resolution of 640x480 pixels, mouse or other pointing device, and Windows 3.1 or Windows 95.

9. COMPUTER SOFTWARE REQUIREMENTS

DOS and Windows 3.1.

10. REFERENCES

D. V. Rao, W. Bernahl, J. Brideau, C. Shaffer, F. Souto, "BLOCKAGE 2.5 User's Manual," NUREG/CR-6370 (SEA96-3104-010-A:3) (December 1996).

C. J. Shaffer, W. Bernahl, J. Brideau, D. V. Rao, "BLOCKAGE 2.5 Reference Manual," NUREG/CR-6371 (SEA96-3104-A:4) (December 1996).

11. CONTENTS OF CODE PACKAGE

Included in the package are the referenced documents and two DS/HD diskettes in DOS format. Included on Diskette #1 is a README file with installation instructions.

12. DATE OF ABSTRACT

January 1999.

KEYWORDS: HEAT TRANSFER; LOCA; MICROCOMPUTER; THERMAL HYDRAULICS