Exelon BWR Spring 2016 Outages Plant Experience Reports
Exelon BWR Spring 2016 Outages Plant Experience Reports LaSalle Unit 1
L1R16 February/March 2016
LaSalle Unit 1 Spring 2016 Scope – Non-Standard Inspections • Jet Pump Adapter Welds (AD-1/AD-2) − Configuration unique to LaSalle Unit 1 and Fermi Unit 2 − First-time use of GEH JPCAS ultrasonic tooling at LaSalle • Used at Fermi, but LaSalle clearances are tighter; required tooling redesign − Results: No indications identified − Significant access restrictions • Jet pump sensing line clamps • Proximity of shroud support gussets • Inconsistent width of opening
• Jet Pump Riser Brace RS-9 Welds − First-time use of GEH ultrasonic tooling − Confirmed flaws previously identified visually 2
LaSalle Unit 1 Spring 2016 – Notable Results • Jet Pump Auxiliary Wedge wear − One Aux Wedge (Jet Pump 16) had reached lower limit of travel − Started to wear into Jet Pump mixer above belly band − Aux Wedge was removed, confirmed no set screw gap − Lesson Learned: Previous inspection in 2010 showed wedge was essentially at lower limit of travel – missed opportunity to address − Examined all aux wedges for travel – no other issues • In-core Monitor Dry Tubes − Replaced 4 IRM/SRM Dry Tubes (all original creviced dry tubes have now been replaced on Unit 1) − Examined 4 IRM/SRM Dry Tubes • 1 of 4 found with lack of full plunger engagement • Accepted for one cycle
3
LaSalle Unit 1 Spring 2016 • Lesson Learned regarding oversight of inspections • Angle/lighting of exam contributed to missing a previously identified indication. Issue was caught post-outage during paperwork review • Re-classified exam results as ‘Recordable Indication’ and scheduled re-exam for next outage.
4
LaSalle Unit 1 Spring 2016
QUESTIONS
5
L1R16 February/March 2016
LaSalle Unit 1 Spring 2016 Scope – Non-Standard Inspections • Jet Pump Adapter Welds (AD-1/AD-2) − Configuration unique to LaSalle Unit 1 and Fermi Unit 2 − First-time use of GEH JPCAS ultrasonic tooling at LaSalle • Used at Fermi, but LaSalle clearances are tighter; required tooling redesign − Results: No indications identified − Significant access restrictions • Jet pump sensing line clamps • Proximity of shroud support gussets • Inconsistent width of opening
• Jet Pump Riser Brace RS-9 Welds − First-time use of GEH ultrasonic tooling − Confirmed flaws previously identified visually 2
LaSalle Unit 1 Spring 2016 – Notable Results • Jet Pump Auxiliary Wedge wear − One Aux Wedge (Jet Pump 16) had reached lower limit of travel − Started to wear into Jet Pump mixer above belly band − Aux Wedge was removed, confirmed no set screw gap − Lesson Learned: Previous inspection in 2010 showed wedge was essentially at lower limit of travel – missed opportunity to address − Examined all aux wedges for travel – no other issues • In-core Monitor Dry Tubes − Replaced 4 IRM/SRM Dry Tubes (all original creviced dry tubes have now been replaced on Unit 1) − Examined 4 IRM/SRM Dry Tubes • 1 of 4 found with lack of full plunger engagement • Accepted for one cycle
3
LaSalle Unit 1 Spring 2016 • Lesson Learned regarding oversight of inspections • Angle/lighting of exam contributed to missing a previously identified indication. Issue was caught post-outage during paperwork review • Re-classified exam results as ‘Recordable Indication’ and scheduled re-exam for next outage.
4
LaSalle Unit 1 Spring 2016
QUESTIONS
5
