Status of Neutron Dosimetry Cross Sections

Abstract

Several new cross section libraries,such as ENDF/B-VI (release 2), IRDF-90, JEF-2.2, and JENDL-3 Dosimetry, have recentlybeen made availableto the dosimetrycommunity. The SandiaNational Laboratories(SNL) RadiationMetrology Laboratory(RML) has worked with these libraries since pre-release ve;sions were available. This papersummarizes theresults of the intercomparisonand testing of dosimetry cross sections. As a result of this analysis, a compendium of the best dosimetry cross sections was assembled from the available librariesfor use within the SNL RML. This library,referredto as the SN-LRML Library,contains 66 general dosimetry sensors and3 special dosimetersunique to the RML sensor inventory. The SNLRML cross sections have been put into a formatcompatible with commonly used spectrum determinationcodes. Several new cross section librarieshave been made available to the dosimetry community. These include the ENDF/B-VI [1,2], the InternationalReactorDosimetry File (IRDF-90) [3], the JapaneseEvaluated Nuclear Data Library(JENDL-3) [4], the USSR EvaluatedNeutron Data Library(BROND) [5], the Joint EvaluatedFile (JEF-2.2) [6], anupdatedORNL GLUCS [7] evaluation, InternationalLibraryof Neu-tronActivation CrossSection Data for Fusion ReactorApplications(FENDL-2) [8], andChinese Evaluated Nuclear Data Library(CENDL) [9,10]. Table1 summarizes theavailable libraries, comments on the scope of thelibraryandthe issue date. Throughtheiruse as activationsensors for determiningneutronspectraand fluence, these new dosimetry cross sections affect the characterizationof neutron radiationdamage facilities, the use of monitor foils to relate a given device irradiationto the specified environment, the comparison of device damage between reactor facilities, and the comparison of radiation-hardening test environments with anticipatedoperatingenvironments. The Sandia National Laboratories(SNL) Radiation Metrology Laboratory (RML) has worked with versions of these cross sections since pre-release datawere available. These new cross sections have been comparedwith each other andevaluated with respect to their accuracyand consistency for spectrum unfolding applications. A compendium of dosimetry cross sections was assembled for use within the SNL RadiationMetrology Laboratory.This library, referredto as the SNLRMLlibrary [11],was empiricallytest-1Senior Member of the Technical Staff,