ML060950262

GALL AMP: XI.E5, Fuse Holder (Audit Worksheet GALL Report AMP)

ML060950262
Person / Time
Site:	Vermont Yankee
Issue date:	03/22/2006
From:	Morgan M NRC/NRR/ADRO/DLR/RLRC
To:	Office of Nuclear Reactor Regulation
morgan M NRR/NRC/DLR/RLRC, 415-2232
Shared Package
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References
%dam200611, TAC MC9668
Download: ML060950262 (5)

Text

AUDIT WORKSHEET GALL REPORT AMP PLANT: ______________________________

LRA AMP: __________________________ REVIEWER: ______________________

GALL AMP: XI.E5, Fuse Holders DATE: __________________________

Program Auditable GALL Criteria Documentation of Audit Finding Element Program A. Fuse holders (fuse blocks) are classified as a specialized Consistent with GALL AMP: Yes No Description type of terminal block because of the similarity in fuse holder Document(s) used to confirm Criteria:

design and construction to that of a terminal block. Fuse holders are typically constructed of blocks of rigid insulating material, such as phenolic resins. Metallic clamps (clips) are attached to the blocks to hold each end of the fuse. The Comment:

clamps, which are typically made of copper, can be spring-loaded clips that allow the fuse ferrules or blades to slip in, or they can be bolt lugs, to which the fuse ends are bolted.

B. GALL XI.E1, Electrical Cables and Connections Not Subject Consistent with GALL AMP: Yes No to 10 CFR 50.49 Environmental Qualification Requirements, Document(s) used to confirm Criteria:

will manage the aging of insulating material but not the metallic clamps of the fuse holders. The aging management program for fuse holders (metallic clamps) needs to account for the following aging stressors, if applicable: fatigue, mechanical stress, Comment:

vibration, chemical contamination, and corrosion. GALL XI.E1 is based on only a visual inspection of accessible cables and connections. Visual inspection is not sufficient to detect the aging effects from fatigue, mechanical stress, vibration, or corrosion on the metallic clamps of the fuse holder.

C. Fuse holders that are within the scope of license renewal Consistent with GALL AMP: Yes No should be tested to provide an indication of the condition of the Document(s) used to confirm Criteria:

metallic clamps of the fuse holders. The specific type of test performed will be determined prior to the initial test, and is to be XI.E5 Fuse Holders 1

Program Auditable GALL Criteria Documentation of Audit Finding Element a proven test for detecting deterioration of metallic clamps of the fuse holders, such as thermography, contact resistance testing, Comment:

or other appropriate testing justified in the application.

D. As stated in NUREG-1760, Aging Assessment of Safety- Consistent with GALL AMP: Yes No Related Fuses Used in Low and Medium-Voltage Applications in Document(s) used to confirm Criteria:

Nuclear Power Plants, fuse holders experience a number of age-related failures. The major concern is that failures of a deteriorated cable system (cables, connections including fuse holders, and penetrations) might be induced during accident Comment:

conditions. Since they are not subject to the environmental qualification requirements of 10 CFR 50.49, an aging management program is required to manage the aging effects.

This program will ensure that fuse holders will perform their intended function for the period of extended operation.

1. Scope of A. This program applies to fuse holders located outside of active Consistent with GALL AMP: Yes No Program devices and are considered susceptible to aging effects. Fuse Document(s) used to confirm Criteria:

holders inside an active device (e.g., switchgears, power supplies, power inverters, battery chargers, and circuit boards) are not within the scope of this program.

Comment

2. Preventive A. No actions are taken as part of this program to prevent or Consistent with GALL AMP: Yes No Actions mitigate aging degradation. Document(s) used to confirm Criteria:

Comment:

3. Parameters A. This program will focus on the metallic clamp portion of the Consistent with GALL AMP: Yes No Monitored/ fuse holder. The monitoring includes thermal fatigue in the form Document(s) used to confirm Criteria:

Inspected of high resistance caused by ohmic heating, thermal cycling or electrical transients, mechanical fatigue caused by frequent removal/replacement of the fuse or vibration, chemical contamination, corrosion, and oxidation. Comment:

XI.E5 Fuse Holders 2

Program Auditable GALL Criteria Documentation of Audit Finding Element

4. Detection of A. Fuse holders within the scope of license renewal will be Consistent with GALL AMP: Yes No Aging Effects tested at least once every 10 years. Testing may include Document(s) used to confirm Criteria:

thermography, contact resistance testing, or other appropriate testing methods. This is an adequate period to preclude failures of the fuse holders since experience has shown that aging degradation is a slow process. A 10-year testing interval will Comment:

provide two data points during a 20-year period, which can be used to characterize the degradation rate. The first tests for license renewal are to be completed before the period of extended operation.

5. Monitoring A. Trending actions are not included as part of this program Consistent with GALL AMP: Yes No and Trending because the ability to trend test results is dependent on the Document(s) used to confirm Criteria:

specific type of test chosen. However, results that are trendable provide additional information on the rate of degradation.

Comment:

6. Acceptance A. The acceptance criteria for each test are defined by the Consistent with GALL AMP: Yes No Criteria specific type of test performed and the specific type of fuse Document(s) used to confirm Criteria:

holder tested.

Comment:

7. Corrective A. An engineering evaluation is performed when the test Consistent with GALL AMP: Yes No Actions acceptance criteria are not met in order to ensure that the Document(s) used to confirm Criteria:

intended functions of the fuse holders can be maintained consistent with the current licensing basis. Such an evaluation is to consider the significance of the test results, the operability of the component, the reportability of the event, the extent of the Comment:

concern, the potential root causes for not meeting the test acceptance criteria, the corrective action necessary, and the likelihood of recurrence. As discussed in the appendix to this report, the staff finds the requirements of 10 CFR Part 50, Appendix B, acceptable to address the corrective actions.

XI.E5 Fuse Holders 3

Program Auditable GALL Criteria Documentation of Audit Finding Element

8. A. As discussed in the appendix to this report, the staff finds the Consistent with GALL AMP: Yes No Confirmation requirements of 10 CFR Part 50, Appendix B, acceptable to Document(s) used to confirm Criteria:

Process address the confirmation process.

Comment:

9. A. As discussed in the appendix to this report, the staff finds the Consistent with GALL AMP: Yes No Administrative requirements of 10 CFR Part 50, Appendix B, acceptable to Document(s) used to confirm Criteria:

Controls address the administrative controls.

Comment:

10. Operating A. Operating experience has shown that loosening of fuse Consistent with GALL AMP: Yes No Experience holders and corrosion of fuse clips are aging mechanisms that, Document(s) used to confirm Criteria:

if left unmanaged, can lead to a loss of electrical continuity function.

Comment:

XI.E5 Fuse Holders 4

EXCEPTIONS Item Program Elements LRA Exception Description Basis for Accepting Exception Documents Reviewed Number (Identifier, Para.# and/or Page #)

1.

2.

ENHANCEMENTS Item Program Elements LRA Enhancement Description Basis for Accepting Enhancement Documents Reviewed Number (Identifier, Para.# and/or Page #)

1.

2.

DOCUMENT REVIEWED DURING AUDIT Document Number Identifier (number) Title Revision and/or Date 1.

2.

3.

4.

XI.E5 Fuse Holders 5