1. NAME AND TITLE OF DATA LIBRARY

DECAYREM: Radioactive Decay Spectra in EXREM Format.

2. NAME AND TITLE OF DATA RETRIEVAL PROGRAM

DKPRINT: A Program for Printing EXREM Data Base.

3. CONTRIBUTOR

Oak Ridge National Laboratory, Oak Ridge, Tennessee.

4. HISTORICAL BACKGROUND AND INFORMATION

The EXREM III program calculates dose rates and total internal dose equivalent due to environmental releases of radioactive material. The program was revised in 1973 to treat positron and conversion/Auger electron emission as well as beta rays and photons which had been treated in EXREM III.

5. APPLICATION OF THE DATA

The data may be used in any application requiring a knowledge of the radiations from radioactive nuclide decay.

6. SOURCE AND SCOPE OF DATA

The data base provided RSIC has decay spectra and nuclide chain information for 252 nuclides. The 1978 revision included a few corrections and some additional nuclides, particularly daughters of some long-lived odd-mass transuranics which were not included previously. The data files now contain all the radioactive decay data listed in Kocher (1977).

The following data are given: decay constant (hr^-1), energy spectra of photons (gamma rays and X rays), beta rays (end-point energies), positrons (end-point energies), and electrons (conversion or Auger). The decay chain information is given in terms of pathways with each pathway being a possible sequence in the decay chains.

The pathway information may be described by an example. Each nuclide has an identifying number (ID) given with each set of data for that nuclide. Assume that nuclide 65 decays to nuclide 66 with 1.8% probability and to 67 with 98.2% probability. Nuclide 66 decays entirely to 67 and 67 is stable. The pathway information is given as follows:

65 66 67

.018 1. 1.

65 1067

.982

The number 1000 (formerly 500) is added to 67 in the second pathway to indicate that a previous pathway must be added to calculate the concentration of nuclide 67.

7. DISCUSSION OF THE DATA RETRIEVAL PROGRAM

The retrieval program prints the data in a more readable form. It also converts the decay constant to half-life (hours/days/years), prints a list of the nuclides by atomic number and looks up the nuclide name (chemical symbol and atomic weight) for the pathway data.

8. DATA FORMAT AND COMPUTER

EBCDIC card images; IBM 360/370.

9. TYPICAL RUNNING TIME

On the IBM 360/91, it required 8 sec (GO) CPU time to obtain a complete printout.

10. REFERENCES

a. Included in the documentation:

D. K. Trubey, "Updating of EXREM III," Informal note (June 1974).

D. K. Trubey, "DECAYREM Notes," Informal note (May 1974).

b. Background information:

D. C. Kocher, "Nuclear Decay Data for Radionuclides Occurring in Routine Releases from Nuclear Fuel Cycle Facilities," ORNL/NUREG/TM-102 (August 1977).

11. CONTENTS OF LIBRARY

Included are the referenced documents (10.a) and one (1.2MB) DOS diskette which contains the library, retrieval program, and sample problem input and output.

12. DATE OF ABSTRACT

April 1978; reviewed May 1984.