LLNL's Computational Nuclear Physics Group and Nuclear Theory and Modeling Group have collaborated to produce the next iteration of LLNL's evaluated nuclear database ENDL2009. ENDL2009 is the second in a series of major ENDL library releases designed to support LLNL's current and future nuclear data needs. This library contains many new evaluations for radiochemical diagnostics, structural materials, and thermonuclear reactions. We have striven to keep ENDL2009 at the leading edge of nuclear data library development by reviewing and incorporating new evaluations as they are made available to the nuclear data community. In addition, ENDL2009 support new features such as energy dependent Q values from fission and unresolved resonances. Furthermore, this is the first ENDL library release to be released in the TDF format. Finally, this release is our most highly tested release as we have strengthened our already rigorous testing regime by adding tests against LANL Activation Ratio Measurements and many more new critical assemblies. Our testing is now being incorporated into our development process and is serving to guide library improvements. Contents

We have developed a program called FUDGE that allows one to modify data from LLNL's nuclear database. After modifying data, FUDGE can then be instructed to process the data into the formats used by LLNL's deterministic (ndf) and the Monte Carlo (MCAPM) transport codes. This capability allows users to perform nuclear data sensitivity studies without modification of the transport modeling codes. FUDGE is designed to be user friendly (object-oriented) and fast (the modification and processing typically takes about a minute). It uses Python as a front-end, making it flexible and scriptable. Comparing, plotting, and printing of the data are also supported. An overview of FUDGE will be presented as well as examples.

FUDGE (For Updating Data and Generating Evaluations) is an open-source code that supports reading, visualizing, checking, modifying, and processing nuclear reaction and decay data. For ease of use the front-end of FUDGE is written in Python while C and C++ routines are employed for computationally intensive calculations. FUDGE has been developed primarily at Lawrence Livermore National Laboratory (LLNL) with contributions from Brookhaven National Laboratory (BNL). It is used by the LLNL Nuclear Data and Theory (NDT) group to deliver high-quality nuclear data libraries to users for a variety of applications. FUDGE is also the world leader in converting data to the Generalized Nuclear Database Structure (GNDS) and working with GNDS data, including processing and visualizing. GNDS is a new extensible hierarchy that has been internationally adopted as the new standard for storing and using nuclear data libraries, replacing the previous standard ENDF-6. A new public release of FUDGE has recently been published on github. This paper gives an overview of nuclear data processing capabilities in FUDGE, as well as describing the latest release, new capabilities, future plans, and basic instructions for users interested in applying FUDGE to their nuclear data workflow.

We discuss how the fission Q values for 235 U, 238 U and 239 Pu depend on the energy of the incident neutron. We then describe how these values have been implemented in mcfgen etc.

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