ML20029C369
| ML20029C369 | |
| Person / Time | |
|---|---|
| Site: | Wolf Creek  |
| Issue date: | 03/21/1991 |
| From: | Bailey J WOLF CREEK NUCLEAR OPERATING CORP. |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| NO-91-0091, NO-91-91, NUDOCS 9103270230 | |
| Download: ML20029C369 (5) | |
Text
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i WQLF CREEK NUCLEAR OPERATING CORPORATION John A Cailey Vice Ptetudent or* uons March 21,1991 NO 91-0091 U. S. Nuclear Regulatory Commission ATTN: Document Control Desk Mail Station P1-137 Washington, D. C.
20555
Subject:
Docket No. 50-582:
Request for Use of Code Case N-458 for RCP Flywheel Examinations
)
Gentlemeni The purpose of this letter is to request approval for the use of ASME Section XI Code Case N-458,
' Magnetic Particle Examination of Coated Materials,Section XI, Division l', pursuant to 10 CFR 50.55a(a)(3).
Technical Specification 4.4.10 requires that each reactor coolant pump (RCP) flywheel be inspected per the recommendations of Regulatory Position C.4.b of Regulatory Guide 1.14 Revision 1 August 1975,
' Reactor Coolant Pump Flywheel Integrity." Regulatory Position C.4.b(2) of this Regulatory Guide recommends a surface examination of all exposed surfaces and a complete ultrasonic volumetric examination be performed at approximately 10-year intervals.
A spara RCP motor, currently shared between Wolf Creek Generating Staticn (WCGS) and the Callaway Nuclear Plant, allows RCP motors to be rotated out of service for refurbishment at a vendor shop.
The flywheel is removed as part of the motor refurbishment activities.
An ultrasonic volumetric examination is scheduled to be performed at that time along with surface examinations of the bore and keyway areas of the flywheel using dye penetrant testing.
The bore and keyways are the most highly stressed area of the flywheel.
The remainder of the flywheel surface is covered with a protective coating.
This would normally preclude a surface examination without extensive efforts to remove the coating.
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9103270230 910?21 PDR ADOCK 05000482
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l NO 91-0091 Page 2 Code Case N-458 provides supplementary rules which may be used for performing a magnetic particle exanination on coated ferritic materials without removal of the coating.
This Code case wus approved by ASME Boiler and Pressure Vessel Code Committee on August 14,
- 1990, but is not included in the most recent listing of HRC approved Code cases in Revision 8 of Regulatory Guide 1.147,
' Inservice Inspection Code Case Acceptability ASHE Section IX Division 1.'
By using the methods described in this Code
- case, a surfcce examination of the coated portions of the RCP flywheole con be performed in accordance with Regulatory Guide 1.14 without requiring removal of the flywheel coating.
Wolf Creek Nuclear Operating Corporation requests approval for use of Code Case N-458 by April 25, 1991 in order to support ongoing offorts to prepare for performance of these inspections.
- l you have any questions concerning this matter, please contact me or Mr. !!. K. Chernoff of my staff.
Very truly yours.
l John A. Bailey Vice President Operations JAB /aem Attachment cci A. T. Howell (NRC), w/a R. D. Martin (NRC), w/a D. V. Pickett (NRC), w/a l
M. E. Skow (NRC), w/a l
Attachment to NO 91-0091 Page 1 of 3 CASE N-458 CASE 5 0F ASME BOILER AND I RESSL'RE \\T.sSEt, CODE Approval Date? August 14.1990 Sn Nunretica f Index for expistion end any rsemimetion dates.
Cs4e N 458
(/) instructions for identification and confirmation Magnetic Particle txamination uf Coated MNerials of suspected flaw indicatiofis Settlon XI, Division 1 (k) recorc"7g er4teria (l) personnel qualification requirements Inquiry: When conducting magnetic particle ex-(m) reference to the procedure qualification ree-amination (MT) in accordance with Section XI, Di-ords vision 1, IWA 2221, which refeiences Article 7 of (n) method of verifying that the ycke lifting power Section V, what supplementary rules may be used for and the !!!undnation source und in the production examining coated ferritic materials by the AC yoke examination are at least as great as spec'fied.
_S techn'.que withcmt removing tM coating?
Reply: It is the opin!on of the Committee that mag-netic particle examina'icn may be conducted in a:.
2.0 EQUIPMEN1' cordance with IWA 2221 using the AC yoke tech-nique on coated ferritic materials without removing (c) A powered powCer blower which prcwides for F
the coating, when ths; applicable requirements of controlled, continuous powder application shall be utilized for application of dry powder, llaad Section XI, Division 1, end the following require
- nqueezed particle applicators shall not be used, ments are met.
(b) Magnetic particles shall contrast with the con-ponent background.
1.0 PROLEDURE (c) Nonconductive rnater.als such as plasde shim stock may be used to simulate nonconductive enat-Magnetic panicle examination shall be performed ings for procedure and personnel qualification.
in accordance with a written procedure. Tl e proce-i dure shallinclude the following:
(a) identification of surface configurations to be 3.0 COATING TillCKNESS examined, metuding coating materials, snaximum qualified coating thickness, and product forms (e.g.,
WSMENT base material or welded surface)
Procedwe demotstration and performance of ex-S (b) surface condition requirements and prepea-aminations shall be preceded Ly meuurement of the tion methods coating thickness in the areas,o be examined, if the (c) manufacturer and model of AC yoke coating is nonconductive, an eddy current techulque (d) manufacturer and type of magnetic panicles may be osed to measure the coating thickness. lf the (c) minimum und maximum yo! s leg separation coating is conducti"e, a magnetic coating thickness
(/) method of measuring coating thickness technique shall be used in 1.ccordance with ASTM (g) identification of the steps in performing the D1186. Coat'ng measurement equipment shall bc examination used in accer, lance with the equipruent manufactur-(h) minimum lighting and AC yoke lifting power er's instructions. Coating tisleknest, measurements requirements (as measured in accordance with 4.0 shall be tsken at the interse:itons 3f a 2 in. matimum below) grid pattern over the area c' examination and at 2 east (i) methods of identifying flaw Indications and dis.
% the maximum yoke leg separation beyond the ex-criminating between flew adications and nonrele-amionilon area. The thinness shall be the mean of s
vant indications (e.g., magnetic writing or particle three sepa2 ate readings within % in. of each inter-held by surface irregularities) rection.
"150 1 SUPP. 6 - NC e
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Attachment to NO 91-0091
.Page 2 of 3 CASE (ctntinued)
N-458 CASES OF ASME BOILER AND PRES $URE W511 CODE l
4.0 W CEDURE QUALIFICATION 6.0 CXAMINATION (a) A qualifica 'on sp :cimen is required. The ma.
(a) Surfaces to 9e examined, and all adjactent terial used for the Deci.nen shall be the same as the areas within at least 1 in., shall be free of all dirt, coated ferromagnet - material to be examined. The grease, lint, scale, welding flux and spatter, oil, and specimen shall be of Jrtilar geometry or weld profile loose, blistered, flaking, or peeling coating.
and contain at iras'. 9 subec crack no longer than (b) Examine the coated item in accordance with
- maximum flaw a t allood in the applicable ac.
the qualified procedure, ve criteria.
(c) If an indicathn greater than 50% of the max-amine the anconted specimen in the most imum allowable fl@.1ze is detected, the coating in thraMc snentation expected during the per-the area of the indlegr4 shall be removed and the formance of the production examination.
examination repeatec.
(c) Document the measured yoke maximum lif'ing Swer, illumination levels, and the results.
(d) Measure Se maximum coating thickness on the item to k exwf,, miin accordance with the re-7.0 DOCUMENTATitN quirements o' 10 abovs.
(a) Procedure qualification 6ut vnnden shall
(.i Coat tLv rp eimen t. lh the same type of coat-include the following:
lug, conducths,5 nonctw etise, te e tximum (1) identification a the procet u thickness measured on the y oductioa item to be ex.
(2) identificathn of the pertu. mi p @rming amined Mternately, nonca.ductive shim stock may and witnessing t e qualification be used to simulate noncotducthc coatings.
(3) de;cription and drawings or sketches of the (f) Examine the coateJ specimen in the most un-qualificsuon specimen, including roating thickness favorable orientation ewpected dming the perform
- measurements and flaw dimension ance of the production examination. Document the (4) equipment and materials used measured yoke muimum lifting power,illu:nination (5) illmnination level and yoke lifting power level, and examinatir,n results.
(6) qualification results, including maximum (g) Comrurc 'he,ength of the indication resulting coating thickness and fisws detected.
from &.@u aw no bnger than the rarimucn (b) Personnel qualification documentation shall
&w size allowed 6; #ae applicable acceparice wi' include the following:
ferla,before and niter crtir4.he coa # thickness (1) name and certification level 3
is qualified when the lenge of the indD on on the (2) identification of the procedure coated surface is at least 50?
- he uugth of the (J) name of Level III administering the qualifi-correspondingindication prios jb yting, cation examination t
(h) Requalification of the pnW % is required (4) description and drawings or sketches of the E't a decrease in either the AC yoketd 'ng power or qualification specimen, including coating thickness thQ)uminated level, or for an increne. in te coating measurements and flaw dimensions thickness.
(S) equipment and materials used (6) illumination level and yoke lifting power (7) qualification results, including maximum 5.0 PERSONNIL QUAllFICAT10?
In addition to the requiremestL iWAC00, per.
sonnd s all be qualified by demonwrsting that they 8.0 Dh.i'NSTRATION can detect the qualification flaws through the maxi.
mum qualified coating thickness using the qudifed The procedure sN be demonstrated to the aat.
f fo< edure, isfaction of the Inspeco.
SUPP. 6 - NC 750.1
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-Attachment to NO 91-0091
- i
-Page 3 of 3 CASE (continued)
N-458 CASES OF ASME BOILER AND PRESSURE \\T.SSEL CODE
9.0 REFERENCES
TO TECHNICAL REPORTS The following Electric Power Research Institute reports are relevant to this Case. Requests for copies should be directed to EPRI Research Reports Cen-ter, Box 50490, F0lo Alto, CA 94303.
NP 5834 - Nondestructive Examination of Welds Through Painted Surfaces, May 1988, i
NP 5951 - Reliability of !iagnetic Particle Inspec-tion Performed Through Coatings, July 1988.
k 750.3
. SUPP. 6 - NC
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