ML20237E209
| ML20237E209 | |
| Person / Time | |
|---|---|
| Site: | San Onofre  |
| Issue date: | 08/26/1998 |
| From: | Rainsberry J SOUTHERN CALIFORNIA EDISON CO. |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| NUDOCS 9808310035 | |
| Download: ML20237E209 (3) | |
Text
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a E. t SOUIHIRN CAllIORMA EDISON-ht"O*L.,
An TDISON Mt.RNA110NAL'* Compuny 1
August 26, 1998
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U..S. Nuclear Regulatory Commission Attention:
Document Control Desk Washington, D.-C. 20555
Subject:
Docket Nos. 50-361 and 50-362 Request to Use Wire Type Image Quality Indicators Second Ten-Year Interval Inservice Inspection Program San Onofre Nuclear Generating Station Units 2 and 3
Reference:
Code Case N 416-1 " Alternative Test Requirement for Welded Repairs
' or Installation of Replacement Items by Welding, Class 1, 2, and 3,Section XI, Division 1" Gentlemen::
This letter requests NRC approval to use wire type Image Quality Indicators (IQIs) in lieu of plaque type penetrameters under 10 CFR 50.55a(a)(3)(1).
This section of the Code of Federal Regulations states:
" Proposed alternatives to the requirements of paragraphs (c), (d), (e), (f),
(g), and (h) of this section or portions thereof may be used when_ authorized
-by the Director of the Office of Nuclear Reactor Regulation. The applicant shall demonstrate that:
1 (1)
The proposed alternatives would provide an acceptable level of quality and safety, or (ii)
Compliance with the specified requirements of this section would result in hardship or unusual difficulty without a compensating increase in the level of quality and safety."
As previously approved (reference), the Southern California Edison Company (SCE) is permitted use of ASME Code Case N-416-1 which invokes the 1992 i
Edition, no Addenda of the ASME Code,Section III in the performance of i
i nondestructive examination of piping weldments.Section III, Articles NB-5111 and NC-5111, require that "... Radiographic examination shall be in accordance with Section V, Article 2, except that...the penetrameters of Table NB-5111-1 9808310035 980826
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Document Control Desk 2
y (NC-5111-1) shall be used in lieu of those shown in Table T-276" (of ASME SectionV). Tables NB-5111-1 and NC-5111-1 specify only plaque type l
penetrameters. They do not address the equivalency or use of wire IQIs, l
although wire type IQI's have been incorporated in these tables in the 1993 Addenda of the 1992 Edition.
Plaque type penetrameters are difficult to use due to placement and shim requirements.
Plaque type penetrameters are suited for use on flat plates and on objects with a geometry such that the penetrometer hole image is not distorted. This is not the case in many nuclear piping components.
In these instances the wire set type IQIs are superior in that they are placed directly across the area of interest, thus encompassing the object's range of density and geometry. Use of plaque type penetrameters can be difficult because the essential T hole is often obscured or distorted due to specimen anomalies, part geometry, or film artifacts outside the area of interest. This creates a re-shoot condition and requires the radiography crew to reenter the radiation area and thus receive extra dose.
The one inch minimum length of the essential IQI wire eliminates the problem of indicator loss due to distortion, anomalies, and part geometry that is commonly found with the target hole in plaque type penetrameters.
The wire type IQIs provide the same function as the plaque type penetrameters by indicating a change in thickness and spatial resolution of the image without the use of shim blocks and pipe standards often required for the plaque type penetrameters.
]
Wire IQIs have been shown to provide quality and sensitivity equivalent to plaque type penetrameters as documented in Table 4 of ASTM E747-87.
Additionally, use of plaque type penetrameters, with their associated stringent placement and shim requirements, has a direct ALARA impact when performing radiography in a nuclear power environment.
This impact is created by the extended time spent in the radiation field due to the set up time associated with the use of shim blocks or pipe standards.
When the plaque type penetrameters do not have a good fit adjacent to or across the area of interest, movement of the shim or plaque can occur.
Movement renders the exposure useless, making it necessary to set up again and re-shoot a weld view.
This has a negative ALARA impact on the radiography crew.
l In addition, the use of wire IQIs eliminates re-shoots due to density variations in the area of interest due to thickness changes in the part because the wires extend across areas of c'ensity variations, providing information across a larger area of the rediograph.
I A
a D
Document Control Desk 3
Equivalent sensitivity has been demonstrated in ASME Section V, Article 22, Standard SE-747.
Because of the equivalent sensitivity, the proposed testing alternative (wire IQIs) provides equivalent testing results to the current testing method (plaque type penetrameters). Therefore, the quality of the inspection and resulting safety of the plant, based on the inspection results, are not impacted by this proposed change.
The intent of this request is to apply the sensitivity level specified in Table NB-5111-1 and NC-5111-1 to the selection of the appropriate wire type IQI from Table 4 of Standard SE-747. The information provided above supports l
that the proposed use of wire IQIs provides an acceptable level of quality and
]
safety, and that the use of plaque type penetrameters results in unusual i
difficulty without a compensating increase in the level of quality and safety.
Therefore, SCE requests permission of the Director of the Office of Nuclear Reactor Regulation to use the wire IQIs as an alternative to plaque type penetrametersundertheprovisionof10CFR50.55a(a)(3)(1).
If you have any questions, please call me.
Sincerely, h
\\
(
cc:
E. W. Merschoff, Regional Administrator, NRC Region IV J. A. Sloan, NRC Senior Resident Inspector, San Onofre Units 2 & 3 J. W. Clifford, NRC Project Manager, San Onofre Units 2 and 3 l
E- _ -_---_---------_------- --_-- _- -
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4 l*
l Document Control Desk 3
A Equivalent sensitivity has been demonstrated in ASME Section V, Article 22, l
Standard SE-747.
Because of the equivalent sensitivity, the proposed testing i
alternative (wire IQIs) provides equivalent testing results to the current testing method (plaque type penetrameters). Therefore, the quality of the inspection and resulting safety of the plant, based on the inspection results, are not impacted by this proposed change.
The intent of this request is to apply the sensitivity level specified in l
Table N8-5111-1 and NC-5111-1 to the selection of the appropriate wire type IQI from Table 4 of Standard SE-747. The information provided above supports i
that the proposed use of wire IQIs provides an acceptable level of quality and safety, and that the use of plaque type penetrameters results in unusual difficulty without a compensating increase in the level of quality and safety.
Therefore, SCE requests permission of the Director of the Office of Nuclear Reactor Regulation to use the wire IQIs as an alternative to plaque type penetrameters under the provision of 10 CFR 50.55a(a)(3)(i).
- If you have any questions, please call me.
Sincerely,
)
s u
cc:
E. W. Merschoff, Regional Administrator, NRC Region.IV J. A. Sloan, NRC Senior Resident Inspector, San Onofre Units 2 & 3 J. W. Clifford, NRC Project Manager, San Onofre Units 2 and 3 l
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