ML25183A345
| ML25183A345 | |
| Person / Time | |
|---|---|
| Issue date: | 06/30/2025 |
| From: | Jeffrey Poehler NRC/RES/DE |
| To: | |
| JEFF POEHLER 3014158353 | |
| Shared Package | |
| ML25183A340 | List: |
| References | |
| Download: ML25183A345 (1) | |
Text
1 2
3 4
5 6
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9 10 11 12 13 14 15 16 17 18 19 A
B C
J K
L M
N O
P Q
R S
T U
V W
X Y
Z AA AB AC AD AE AF AG AH AI AJ AK AL AM AN AO AP AQ AR AS Panelist 1 Panelist 2 Panelist 3 Average ImportanceUncertaintyKnowledge ImportanceUncertaintyKnowledge ImportanceUncertaintyKnowledge Recommendation ID title of recommendation Scope, objectives, and/or topic modifications Score Score Score Rationale Score Score Score Rationale Score Score Score Rationale Importanc e (avg)
Uncertaint y (avg)
Knowled ge (avg) error bars Import Uncert. Know error More research could be used to gain knowledge on a topic expected to be important to safety More research could reduce uncertainty and clarify topic importance More research could improve knowledge but topic not expected to be safety significant Topic expected to have safety significance but likely could be addressed without additional research Topic may have safety significance but sufficient knowledge exists to manage Topic not expected to have safety significance and sufficient knowledge exists H/M/L H/M/L K/PK/UK H/M/L H/M/L K/PK/UK H/M/L H/M/L K/PK/UK CCL-1 Investigate crevice corrosion environment and crevice former and validate using OpE and experiments.
H M
PK Understanding the crevice environment and materials that promote corrosion is crucial to prevent accelerated degradation, especially under LTO.
H L
K Crevice corrosion is a localized corrosion. Frequently it occurs in occluded metallic structures, particularly those of iron content.
Identifying the microenvironment driving its development, however, can be of challenge. Ranking is based on its importance, safety significance, and uncertainty coupled to sufficient understanding of its microenvironment occurence.
H M
PK This is a common degradation and reasonable knowledge exists.
3.0 1.7 1.7 0.277778 2.9850 1.6667 1.6817 0.277778 1
2 1
1 2
CCL-2 Develop reliable comprehensive corrosion modeling.
M M
PK Reliable models support effective aging management programs and safety evaluations, especially for extended operation beyond 80+
years H
L K
The cost of corrosion is high. This demands the development of reliable models and predictions for loss of material in specific electrochemical environment at plants. Accordingly H is assigned for its importance. Existing knowledege drives the rest of the rankings to a lower setting.
M M
PK 2.3 1.7 1.7 0.277778 2.3333 1.6667 1.6667 0.277778 2
2 3
3 2
CCL-3 Develop enehanced inspection and mitigation strategies to prevent crevice corrosion and timely intervention.
M L
K Investigating environmental conditions that lead to corrosion is a critical first step in selecting effective mitigation strategies, supported by prevention measures and condition monitoring.
H L
K The technology for its minimization exists and risks involved in developing crevice corrosion are known. Strategies to prevent or minimize such corrosion ultimately will demand a sound design and construction opting to eliminate offenive environments in constructs.
H M
K Avoid difficult and costly repair.
2.7 1.3 1.0 0.222222 2.6667 1.3333 1.0500 0.222222 3
CCL-1 CCL-2 CCL-3 1
3 2
2 Importance Knowledge Session 8 - Civil Structures, Concrete and Components - Crevice Corrosion Liner (CCL)
High Low Known Unknown