Printed in the UnitedGJ/kgM(28 MWd/kgM) and expected fission gas release of about i%. Characterizationdata includeI) descriptionsof as-fabricatedfuel design, irradiation history, and subsequentstorage and handling;2) isotopicgamma scans;3) fission gas analyses;4) ceramographyof the fuel and metallographyof the clac_ding; 5) special fuel studies involvinganalyticaltransmissionelectron microscopy (AEM); 6) calculatednuclide inventoriesand radioactivitiesin th,afuel and cladding;and 7) radiochemicalanalyses of the fuel and cladd"Jng. Additionalanalysesof the fuel are being conducted and will be _,ncluded in planned revisionsof this report.iii ACKNOWLEDGMENTS

Printed in the UnitedGJ/kgM(28 MWd/kgM) and expected fission gas release of about i%. Characterizationdata includeI) descriptionsof as-fabricatedfuel design, irradiation history, and subsequentstorage and handling;2) isotopicgamma scans;3) fission gas analyses;4) ceramographyof the fuel and metallographyof the clac_ding; 5) special fuel studies involvinganalyticaltransmissionelectron microscopy (AEM); 6) calculatednuclide inventoriesand radioactivitiesin th,afuel and cladding;and 7) radiochemicalanalyses of the fuel and cladd"Jng. Additionalanalysesof the fuel are being conducted and will be _,ncluded in planned revisionsof this report.iii ACKNOWLEDGMENTS

Printed in the UnitedGJ/kgM(28 MWd/kgM) and expected fission gas release of about i%. Characterizationdata includeI) descriptionsof as-fabricatedfuel design, irradiation history, and subsequentstorage and handling;2) isotopicgamma scans;3) fission gas analyses;4) ceramographyof the fuel and metallographyof the clac_ding; 5) special fuel studies involvinganalyticaltransmissionelectron microscopy (AEM); 6) calculatednuclide inventoriesand radioactivitiesin th,afuel and cladding;and 7) radiochemicalanalyses of the fuel and cladd"Jng. Additionalanalysesof the fuel are being conducted and will be _,ncluded in planned revisionsof this report.iii ACKNOWLEDGMENTS

Printed in the UnitedGJ/kgM(28 MWd/kgM) and expected fission gas release of about i%. Characterizationdata includeI) descriptionsof as-fabricatedfuel design, irradiation history, and subsequentstorage and handling;2) isotopicgamma scans;3) fission gas analyses;4) ceramographyof the fuel and metallographyof the clac_ding; 5) special fuel studies involvinganalyticaltransmissionelectron microscopy (AEM); 6) calculatednuclide inventoriesand radioactivitiesin th,afuel and cladding;and 7) radiochemicalanalyses of the fuel and cladd"Jng. Additionalanalysesof the fuel are being conducted and will be _,ncluded in planned revisionsof this report.iii ACKNOWLEDGMENTS

DISCLAIMERPortions of this document m y be illegible in electronic image products. Images are produced from the best available original document. AbstractThe Pacific Northwest Laboratory conducted a comprehensive aging assessment of chillers used in the essential safety air-conditioning systems in nuclear power plants (NPPs). The chillers used, and air-conditioning systems served, vary in design from plant to plant. The review of operating experience indicated that chillers experience aging degradation and failures. The primary aging factors of concern for chillers include vibration, excessive temperatures and pressures, thermal cycling, chemical attack, and poor quality cooling water. The evaluation of Licensee Event Reports (LERs) indicated that about 38% of the failures were primarily related to aging, 55% were partially 'aging related, and 7% of the failures were unassignable. About 25% of the failures were primarily caused by human, design, procedure, and other errors.