RSICC CODE PACKAGE CCC-735

 

1.  NAME AND TITLE

EASY-2005.1:  Multipurpose Activation and Transmutation Code System.

 

2.  CONTRIBUTORS

EURATOM/UKAEA Fusion Association, Oxfordshire, United Kingdom, and CEA Cadarache, CEDEX, France, through the OECD NEA Data Bank, Issy-les-Moulineaux, France.

 

3.  CODING LANGUAGE AND COMPUTER

Fortran and C; PC, Pentium, IBM, Sun, Compaq Alpha. RSICC ID is C00735MNYCP01. (NEADB identifier is NEA-1564/10 for Unix/Linux and NEA-1564/11 for Windows.)

 

4.  NATURE OF PROBLEM SOLVED

The EASY-2005 (European Activation System) consists of a wide range of codes, data and documentation all aimed at satisfying the objective of calculating the response of materials irradiated in a neutron flux. The main difference from the previous version is the upper energy limit which has increased from 20 to 60 MeV. It is designed to investigate both fusion devices and accelerator based materials test facilities that will act as intense sources of high energy neutrons causing significant activation of the surrounding materials. The very general nature of the calculational method and the data libraries means that it is applicable (with some reservations) to all situations (e.g. fission reactors or neutron sources) where materials are exposed to neutrons below 60 MeV.
  
EASY can be divided into two parts: data and code development tools and user tools and data. The former are required to develop the latter, but EASY users only need to be able to use the inventory code FISPACT and be aware of the contents of the EAF library (the data source). The complete EASY package contains the FISPACT-2005 inventory code, the EAF-2005 library, and the EASY User Interface.
  
The activation package EASY-2005 [1] is the result of significant development to extend the upper energy range from 20 to 60 MeV so that it is capable of being used for IFMIF calculations. The EAF-2005 library contains 62,637 reactions, almost five times more than in EAF-2003 (12,617). Such a large increase means that some mistakes may exist in the new file that need to be corrected. Because of these shortcomings and for other reasons explained below, a maintenance release, EAF-2005.1 has been produced.
  
A deuteron-induced cross section library was also included for the first time, and can be used with EASY to enable calculations of the activation due to deuterons [3]. This library is included in the EASY-2005.1 maintenance release as is a new version of the FISPACT code that can use the deuteron library.
  
The EAF-2005 data library covers:
-  Cross section data for neutron-induced reactions
-  Uncertainty data for neutron-induced reactions
-  Decay data
-  Fission yield data
-  Biological hazard data
-  Legal transport data
-  Clearance data
-  Charged particle ranges in materials
-  Emitted particle spectral data (from neutron-induced reactions)
-  Charged particle cross section data
-  Gamma absorption data
  
The EAF-2005 contains the following data libraries:
  
EAF_XS-2005 is the point-wise cross section library. Data on 62,637 cross sections on 775 targets are held in a modified ENDF/B format. The energy range 10e-5 eV - 60 MeV is covered. All nuclides with a half-life of greater than 0.5 day have cross section data, but in addition some short-lived nuclides are also treated as targets. The cross sections represent targets that are infinitely dilute, no self-shielding is included and the temperature for Doppler broadening is 300K. Reference [5] documents the EAF-2005 cross section library.
  
EAF_GXS-2005 is a set of multi-group libraries; the available group structures are: WIMS (69), GAM-II (100), XMAS (172), VITAMIN-J (175), VITAMIN-J+ (211), TRIPOLI (315) and TRIPOLI+ (351). Various choices of micro-flux weighting are available for particular applications. Reference [8] gives more details of the group structures and weightings, reference [5] documents the EAF-2005 cross section library.
  
EAF_UN-2005 contains uncertainty data for all cross sections. This library, in modified ENDF/B-6 format, contains error factor values (in 2 to 4 energy groups) for all reactions and is unique amongst activation libraries. This approach to uncertainties is less comprehensive than that found in general purpose evaluated files, but is of great value for fusion related inventory calculations. Reference [5] documents the EAF-2005 uncertainty library.
  
EAF_DEC-2005 contains decay data information for 2192 nuclides, it is based primarily on the JEF-2.2 radioactive decay data library [10], with additional data from recent UK evaluations. It includes data on half-lives, decay modes and decay energies. Note that entries are included for all stable nuclides. Reference [6] describes the EAF_DEC-2005 library. Care has been taken to ensure that EAF_XS and EAF_DEC are compatible. This is especially important for the identification of isomeric states. All nuclides (including isomeric states) that can be formed from the various reactions in EAF_XS are included so long as their half-lives are greater than 1 second. Some nuclides with shorter half-lives are included where it is felt that they are of particular importance.
  
EAF_FIS-2005 is taken completely from the JEF-2.2 fission yield library. It is a library of independent fission yields in ENDF/B-6 format. Only 19 of the 90 nuclides in EAF_XS which have fission cross sections have any fission yield data in JEF-2.2 at relevant energies. An inventory code using this data source will need a means of using a neighbouring fission yield for such nuclides.
  
EAF_HAZ-2005 is a library of values for each radionuclide describing the potential biological impact of that nuclide on human beings. The format is not ENDF/B-6, but is suitable for input by the FISPACT code. The values are Committed Effective Doses per unit uptake, which determine the dose received by a person over their lifetime (50 years) following the ingestion or inhalation of 1 Bq of activity of a particular radionuclide. Reference [7] documents the EAF_HAZ-2005 library.
  
EAF_A2-2005 is a library of values relevant for the transport of radionuclides in shielded flasks. The format is not ENDF/B-6, but is suitable for input by the FISPACT code. Transport of radioactive material from place to place is governed by regulations set up by the IAEA. Reference [17] gives details of A2 values for certain radionuclides. Using these values it is possible to work out how much of a particular mixture of radioactive materials can be packed into a type of container and safely transported. Data from this reference for the nuclides listed are transferred to EAF_A2, with the use of the default prescription given, for all radionuclides not explicitly listed. Reference [7] documents the EAF_A2-2005 library.
  
EAF_CLEAR-2005 is a library of values relevant for the disposal of radioactive material. The format is not ENDF/B-6, but is suitable for input by the FISPACT code. Reference [7] documents the EAF_CLEAR-2005 library. This contains the clearance limit value for each radionuclide. This value can be used to decide if an amount of a radionuclide can be disposed of with no special precautions.
  
EAF_STOP-2005 contains new data compared to the previous versions. Due to the change of the upper energy limit from 20 to 60 MeV the data have been recalculated. It is required to enable the effect of sequential charged particle reactions (SCPR) to be investigated. Details of this effect and a brief description of the libraries are given in reference [1], but the original report [18] should be consulted for more details. EAF_STOP contains the differential ranges for protons (p), deuterons (d), helions (h), tritons (t) and alpha particles in all the elements from H to U. The term differential range at a particular energy defines the distance travelled by the particle in the material in losing 1 MeV of energy. Data are given from 0 to 60 MeV.
  
EAF_SPEC-2005: EAF_XS contains the cross section data for (n,x) reactions, while EAF_SPEC describes the energy distribution of the charged particles emitted in these reactions. This is the second libraries required for SCPR. The data are calculated by a theoretical model code (TALYS) due to the lack of experimental data. Thirty-nine input neutron energies are used and the outgoing charged particles are in 1 MeV bins covering the energy range 0-60 MeV.
  
EAF_XN-2005 describes the cross sections of p, d, h, t and alpha particles on 775 targets. Ten reactions types are considered: (p,n), (d,n), (h,n), (t,n), (alpha,n), (p,2n), (d,2n), (h,2n), (t,2n) and (alpha,2n). This is the third of the libraries required for SCPR. The data are calculated by a theoretical model code (TALYS) due to the lack of experimental data. The data are given at 1 MeV intervals over the energy range 0-60 MeV.
  
EAF_ABS contains the photon mass energy attenuation coefficient for all the elements Z= 1 - 100 in increasing Z order. The attenuation coefficient and energy absorption coefficient for air are also listed. All data are stored in a 24 group energy structure.

 

5.                METHOD OF SOLUTION

FISPACT is an inventory code developed for neutron-induced activation calculations for materials in fusion devices. The current version is FISPACT-2005, which is the culmination of seventeen years of development. It uses external libraries of nuclear data for all relevant nuclides to calculate the number of atoms of each species at a specified time during the irradiation or after a decay time following shutdown. The various species are formed either by a direct reaction on a starting material, by a series of reactions some of which can be on radioactive targets or by a decay or series of decays. The accuracy of the calculated inventory is dependent on the quality of the input nuclear data - the cross sections and decay properties - the European Activation File (EAF) is the recommended source of data.

SAFEPAQ-II is the software tool used for the maintenance and development of the EAF nuclear data library by UKAEA. The SYMPAL processing system that originated at ECN Petten was used for cross section library processing prior to EAF-2001.

              

6.  RESTRICTIONS OR LIMITATIONS

The upper energy limit is 60 MeV.

 

7.  TYPICAL RUNNING TIME

Run times vary. Test cases completed in ~15 minutes under WindowsXP on a Pentinum IV 3GHz.

 

8.  COMPUTER HARDWARE REQUIREMENTS

EASY runs on IBM compatible PC’s running Microsoft Windows or Linux and on Mac OS X, IBM RS/6000, Alpha and Sun workstations.

 

9.  COMPUTER SOFTWARE REQUIREMENTS

Executables created by the developers are included for IBM-AIX, Compaq-ALPHA, SUN-Solaris, Mac OS X, Pentium running Red Hat Linux and Windows. The included Windows executable was run at RSICC on Pentium IV computers running Windows XP, and the Linux executable was run on an AMD Opteron under Red Hat Enterprise Linux. Fortran source files and Makefiles are in the Unix/Linux distribution but are not included in the Windows distribution.

 

10. REFERENCES:

10.a included in Windows and Unix distribution in electronic files:

1. R.A. Forrest, “The European Activation System: EASY-2005 Overview,” UKAEA FUS 513 (2004).
2. R.A. Forrest, “EASY-2005.1: Summary” (Dec. 2005).
3. R.A. Forrest, “Deuteron-Induced Activation in the IFMIF Lithium Loop” (Nov. 2005).
4. R. A. Forrest, J. Kopecky, M. Pillon, K. Seidel, S. P. Simakov, P. Bém, M. Honusek and E. Šimecková, “Validation of EASY-2005 using integral measurements,” UKAEA FUS 526 (Jan. 2006).
5. R.A. Forrest, J Kopecky and J-Ch Sublet, “The European Activation File: EAF-2005 cross section library,” UKAEA FUS 515 (2004).
6. R.A. Forrest, “The European Activation File: EAF-2005 decay data library,” UKAEA FUS 516 (2004).
7. R.A. Forrest, “The European Activation File: EAF-2005 biological, clearance and transport libraries,” UKAEA FUS 517 (2004).
8. R.A. Forrest and M.R. Gilbert, “FISPACT-2005: User Manual,” UKAEA FUS 514 (2004).
9. R.A. Forrest, “SAFEPAQ-II: User Manual,” UKAEA FUS 454, Issue 6 (2004).
10. JEF-2.2 Radioactive Decay Data,” JEF Report 13 (August 1994).

10.b included in directory documents_2003:

11. R.A Forrest, “The European Activation System: EASY-2003: Overview,” UKAEA FUS 484 (1, December. 2002).
12. R.A. Forrest, “FISPACT-2003: User Manual,” UKAEA FUS 485 (1, December 2002).
13. R.A.  Forrest, J Kopecky and J-Ch. Sublet, “The European Activation File: EAF-2003 Cross Section Library,” UKAEA FUS 486 (1, December 2002).
14. R.A.  Forrest, “The European Activation File: EAF-2003 Decay Data Library,” UKAEA FUS 487 (1, December 2002).
15. R.A.  Forrest, “The European Activation File: EAF-2003 Biological, Clearance and Transport Libraries,” UKAEA FUS 488 (1, December. 2002).
16. R.A.  Forrest, “SAFEPAQ-II: User Manual,” UKAEA FUS 454 (5, December 2002).

10.c background references (not included in distribution)

17. Regulations for the safe transport of radioactive material, 1985 edition, (and supplement 1988), Safety Series No 6, IAEA, Vienna
18. S. Cierjacks, P. Oblozinsky and B. Rzehorz, “Nuclear data libraries for the treatment of sequential (x,n) reactions in fusion materials activation calculations,” KfK 4867, 991.
19. J.A. Simpson and J-Ch Sublet, “SYMPAL: Utilities guide,” UKAEA FUS 357 (1997).
20. R.A. Forrest and J.A. Simpson, “SAFEPAQ: User manual,” UKAEA FUS 355 (1997).

 

11. CONTENTS OF CODE PACKAGE

The package is transmitted on 1 DVD which contains the reports listed above, executable files for all computer systems named above, source codes, Windows installer, data libraries and test cases.

 

12. DATE OF ABSTRACT

May 2007, revised August 2008.

 

KEYWORDS:  ACTIVATION; FUSION; ISOTOPE INVENTORY; CROSS SECTIONS