1CAN129703, Requests Relief for RCS Weld Exam,From Requirements of 10CFR50.55(a)(g).Relief Request for 2 Welds Whose Volumes Could Not Be Examined 100%,encl

Requests Relief for RCS Weld Exam,From Requirements of 10CFR50.55(a)(g).Relief Request for 2 Welds Whose Volumes Could Not Be Examined 100%,encl

ML20202H579
Person / Time
Site:	Arkansas Nuclear
Issue date:	12/03/1997
From:	Mims D ENTERGY OPERATIONS, INC.
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
1CAN129703, NUDOCS 9712100316
Download: ML20202H579 (4)

Text

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cntergy opetauons,Inc.

M{jh[ 1448 SA 333 Russoh@, AR 72801 Td 501858 5000 December 3,1997 1CAN129703 U. S. Nuclear Regulatory Commission Document Control Desk Mail Station OPI-17 Washington, DC 20555

Subject:

Arkansas Nuclear One - Unit 1 Docket No. 50-313 License No. DPR-51 Request for Relief for Reactor Coolant System Weld Examination Gentlemen:

The purpose of this submittal is to request relief from the requirements of 10CFR50.55(a)(g).

Entergy Operations at Arkansas Nuclear One, Unit 1 (ANO-1) was unable to examine 100%

of the weld volumes of two reactor coolant system welds during the last inservice inspection

-(ISI). Attached is a relief request for the two welds whose volumes could not be examined 100%. This request is for the second interval which ended June 1,1997. Should you have any questions, please contact me.

Very truly yours, wi .Mims Direct , Nuclear Safety DCM/nbm  ;

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U. S. NRC Decenk 3,1997 ICAN129703 Page 2 cc:

Mr. Ellis W. Merschoff Regional Administrator-U. S. Nuclear Regulatory Commission Region IV 611 Ryan Plaza Dnve, Suite 400 Arlington, TX 76011-8064 NRC Senior Resident Inspector i Arkansas Nuclear One P.O. Box 310 L4, AR 72847 l

Mr. George Kalman NRR Project Manage- Region IV/ANO-1 & 2

, U. S. Nuclear Regulatory Commission l NRR Mail Stop 13-H-3 One White Flint North 11555 Rockville Pike ,

Rockville, MD 20852 e

Attachment to -

s ICAN129703 Y Page1 of2 3 ANO-1 Inse vice laspection Relief Request 96-005 Ceenonent Identification Code Class: 1 ApplicableInterval: Second

- Applicable Edition and Addenda of ASME Section XI: 1980 Edition with Adde.4 through Winter 1981 Code Examination Category: B-D, B-F CodeItemNumbers(s): B3,130 B5.130 Code Required. Examination: Voluartric examination of pressure-retaining full-penetration nozzle-to-vessel welds in steam, generators (primary side); volumetric and surface examination of pressure-retaining dissmular metal welds Component (s) or Relief Area (s):

• Steam generator E24B inlet-nozzle-to-upper-head weld, ISI exam number 04-004 e- Steam generator E24B to reactor coolant pump P32A pipe-to-pipe circumferential scam,ISI exam number 10 002 Reautrement from which Reliefis Reauested:

)

Code Case N-460 requires that when the entire examination volume or area cannot be a==taad due to interference by another component or part geometry, a reduction in examination coverage on any class 1 or class 2 weld may be accexed provided the it reduction in covernoe for that weld is less than 10%. Durinal refueing outage 1Ril, which ended in Octo ar of 1993, the two pressure-retaining wek listed above received an examination that had a reduction in coversae far the weld greater than the 10% allowed by Code Case N-460 reguirements. The ack of completeness of the examination is a result oflimited accessibihty due to geometry and interference by another component.

Bashfor_ Relief:

The Code of Federal Regulations 10CFR50.55(a)(g) and ANO-1 Technical Specification 4.0,5 require that ASME Code Class 1,2, and 3 systems be rout'mely inspected as an assurance of continued structural id grity of the reactor coolant system pressure boundary. These regular inwjons must be performed per Section XI of the ASME Boiler and Pressure Vessel dode.Section XI, which is entitled " Rules for Inservice Insation of Nuclear Power Plant Components," requires the inspection of all class I we ds (Code Category B-D and B-F) once during each 10-year interval of operation.

Attachment to .

. ICAN129703 Page 2 cf 2 The obstructions located on or adjacent to these welde produce an area in which it is very difficult or impossible to maneuver the ultrasonic transducer in a way to obtain full ooverage of the welds. For ISI exam number 04 004 the percent of coverage is 47.6%,

and for ISI exam number 10-002 the percent of coverage is 85.78%. The results of the

- limited examinations were that no semce-induced flaws were found in either of the welds inspected.

- Since com>lete examination of these welds is not practical, Entergy Operations has examined tw ANO-1 welds to the maximum extent possible using the technologies that are commercially available. Examination of the accessible weld volumes is sufficient to provide accessible reasonable assurance welds have revealed of system integrity,d no service-induce flaws.espially since past examination It is therefore reasonable to conclude that the same results would be obtained for the inaccessible portions of the welds ifit were possible to inspect them.

l Inspection ofless than 100% of the weld volumes does not endanger the public since the ' i reactor coolant rystem is designed and constructed to have a low probability of gross rupture or significant i e throughout its desi3n life. In addition, any leakage that might occur would be easil elected and containec within the reactor building.

Alternative Exa=I==tions:

As part of the continuing regularly-scheduled inservice inspection scope, the other Category B-D welds have been exammed ultrasonically. In addition, the steam generators -  ;

receive a visual (VT-2) examination each refueling outage. No service-induced cracking or degradation has been found either with the ultrasonic examinations or with the visual e inspections.

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