MTA-LS-001

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Administrative Items
Date	12/15/2020
Functional Area Where Benefits Will Be Realized	Licensing Engineering Quality Control
Reference Implementation Guidance	2017 NEI TIP Awards – Submittal 20 (ID: 10107888)
Industry SME	EPRI Boiling Water Reactor Vessel and Internals Program Contact: NuclearPlantMod@epri.com
Previous Implementation	Please contact EPRI for implementation examples and contacts.
Implementation Enablers	N/A
Applicability	Most BWR 3/4/5 configurations All geographic regions
Keywords	Core shroud; off-axis flaws; ultrasonic technique; boiling water reactor; flaw evaluation; inspection strategy; vessel and internals
Business Case Analysis Cross-Reference	N/A

Description

The Boiling Water Reactor Vessel Internals Project (BWRVIP) requires that core shrouds be inspected using ultrasonic testing (UT) and/or visual inspections. Flaw indications in core shroud inspections are typically parallel to the welds in the heat affected zone; however, flaws that are perpendicular to the welds and heat affected zone can also be present. These indications are known as Off‑Axis Flaws (OAFs). BWRVIP issued an interim guidance letter in 2016 that requires one‑time core shroud inspections using techniques capable of detecting OAFs.

UT inspection using traditional methods would require different techniques to detect the horizontal and vertical flaws. The subject of this MTA is a single tool that can be used to perform the entire core shroud inspection, with the ability to inspect vertical and horizontal welds and detect OAFs. It uses UT to detect all possible flaw orientations while minimizing the number of times the tooling would need to be removed and returned to the reactor vessel.

Benefits

Benefits Estimate

Level 1 – Savings are less than $1 million per year. Potential savings are achieved through reduction in core shroud inspection time and personnel.

Benefits Description

• Reduction in time for inspections, which often impacts critical path for refueling outages.
• Reduction in dose due to eliminating tool removal/decontamination/reconfiguration/reinstallation.
• Reduction in data acquisition time relative to typical UT techniques.
• Improved quality of data and signals for analysis relative to typical UT techniques.

Costs and Schedule

Cost

Level 3 – The inspection cost using the tool should be limited to $1 million or less.

Schedule

Less than six months for pre‑outage planning to prepare for inspection.

Scope Context

Per unit/per core shroud inspection

Risks

Site‑specific core shroud geometries and possible core shroud repair obstructions may affect the difficulty of the inspection; this may impact the cost and schedule of the core shroud inspection. Proper planning and coordination with the vendor should mitigate this risk.

SWEEEP Score

Category	Level	Description
Cost	3	The inspection cost using the tool should be limited to $1 million or less.
Savings	1	Savings are less than $1 million per year.
Payback	3	Based upon available cost and savings information, the payback period for implementation would be less than one year.
Licensing Readiness	3	This approach has already been implemented at nuclear power plants.
Technology Readiness	3	This approach has already been implemented at nuclear power plants.
Implementation Proficiency	3	The implementation and operation of the tool does not require knowledge in implementing digital technologies.