1. NAME AND TITLE

ESDORA: Fission Product Inventory and Gamma-Ray Dose Rate from a Radioactive Cloud System.

2. CONTRIBUTOR

Junta De Energia Nuclear, Madrid, Spain.

3. CODING LANGUAGE AND COMPUTER

FORTRAN IV; UNIVAC 1108.

4. NATURE OF PROBLEM SOLVED

ESDORA is useful to assess abnormal reactor behavior in hazards evaluations, reactor siting and design of engineered safeguards. The method consists of four major parts which cover the following points: fission product inventory, escape from the reactor containment, atmospheric diffusion and radiation doses.

5. METHOD OF SOLUTION

ESDORA determines the fission product inventory as a function of reactor power, fuel irradiation, and cooling time. It analyzes the fission product behavior within the containment system when released from the core as a result of an accident. Finally, the method calculates the atmospheric diffusion of the escaping nuclides under a variety of atmospheric conditions. External and inhalation doses to individuals within the radioactive plume may be assessed at different distances downwind from the reactor.

The method has been used to evaluate the hazards caused by different types of reactor accidents such as reactivity accidents, loss-of-coolant accidents, reactor fires, and fuel-handling accidents.

Different types of containment systems are considered in the analysis. The systems analyzed include negative pressure containment, double containment, and high-pressure and pressure-suppression containment systems.

The effect of engineered safeguards such as building sprays, filters, condensation pools, etc., can be taken into account. Each nuclide can be considered individually as the cleaning rates, condensation ratios, deposition velocities, etc., are nuclide-dependent.

The results are given in terms of the amounts of the most important nuclides retained within the containment barriers or by the engineered safeguards. The most relevant health hazards produced outside the containment system are also given for the accidents analyzed.

6. RESTRICTIONS OR LIMITATIONS

None noted.

7. TYPICAL RUNNING TIME

No study has been made by RSIC of typical running times for ESDORA.

8. COMPUTER HARDWARE REQUIREMENTS

ESDORA was designed for the UNIVAC 1108 computer.

9. COMPUTER SOFTWARE REQUIREMENTS

A FORTRAN IV compiler is required.

10. REFERENCES

F. Diaz de la Cruz, "Esdora, Computer Program for an Estimate of the Radiation Dose in the Evaluation of Risks for Nuclear Power Plants and Radioactive Facilities," Internal Report SS/01/71 (ORNL-tr-2628) (March 1971).

A. Alonso, "NUBEA Digital Code to Evaluate the Hazards of Different Types of Reactor Accidents," CONF-650407, Volume 2 (April 1965).

11. CONTENTS OF CODE PACKAGE

Included are the referenced documents and one (1.2MB) DOS diskette containing a library of data, source code and sample problem input and output.

12. DATE OF ABSTRACT

May 1975.