Checklist of Steam Generator Repair Safety Issues at Maine
Circumferential cracking in the steam generator.
Ongoing corrosion and deformation processes.
Accumulated residual stress damage from steam generator fabrication
Weld-induced stress damage at the sleeve-tube transition.
Post-weld heat treatment efficacy for repair of weld-induced
"Far-field" stress damage in parent tube resulting from sleeve
welds and post-weld heat treatment.
Steam-tube sludge deposits and corrosion scaling.
Tube deformations (tube bowing and lateral displacement)
induced by sleeve insertion, welding, and sludge deposits.
Sludge deposit, tube plugging, and deformation-induced changes
in pressure gradient and reactor coolant flow.
Increased likelihood of steam tube contact during reactor
Non-uniform sleeve length fails to cover all parent tubing.
Stress resistance and corrosion resistance differentials
between new sleeves and old parent tube and tube welds.
Reduced effectiveness of ultra-sonic weld inspections due
to attenuation of signals by the extensive sludge deposits and tube scaling.
The dilapidated condition of the steam generator is a paradigm
for the condition of the rest of the reactor at Maine Yankee. (Embrittled
reactor vessel, obsolete spent-fuel storage facility, etc.)
Keywords:Keywords: Maine Yankee Atomic Energy,atomic
energy,steam generator,Center for Biological Monitoring,biologically significant
radionuclides,dietary intake,reactor nuclide inventories,decomissioning
costs,violations of nuclear waste policy