L-HU-06-024, Withdrawal of Request for Reliefs 21 and 22 - Request to Use ASME Code Case N-700, Alternative Rules for Selection of Classes 1, 2 and 3 Vessel Welded Attachments for Examination

Withdrawal of Request for Reliefs 21 and 22 - Request to Use ASME Code Case N-700, Alternative Rules for Selection of Classes 1, 2 and 3 Vessel Welded Attachments for Examination

ML061660183
Person / Time
Site:	Prairie Island
Issue date:	06/14/2006
From:	Thomas J. Palmisano Nuclear Management Co
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
L-HU-06-024
Download: ML061660183 (2)

Text

M Commillsd to Nucl Prairie lsland Nuclear Generatinq Plant Operated by Nuclear Management Company, LLC L-HU-06-024 10 CFR 50.55a (a)(3)(i)

U.S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, DC 20555 Prairie lsland Nuclear Plant, Units 1 and 2 Dockets 50-282 and 50-306 License Nos. DPR-42 and DPR-60 Withdrawal of Request for Reliefs 21 and 22 - Request to Use ASME Code Case N-700, Alternative Rules for Selection of Classes 1,2 and 3 Vessel Welded Attachments for Examination.

Reference:

1.NMC letter to NRC L-HU-05-028, American Society of Mechanical Engineers (ASME)Section XI, Inservice Inspection (IS])- Request for Relief 21 and 22 - Request to Use ASME Code Case N-700, Alternative Rules for Selection of Classes 1,2 and 3 Vessel Welded Attachments for Examination, dated December 19, 2005 On December 19,2005, Nuclear Management Company, LLC (NMC) submitted a relief request (Reference I ) , for Prairie Island Nuclear Plant Units 1 and 2 (PINGP), from certain in-service inspection requirements in Section XI of the ASME Boiler and Pressure Vessel Code, specifically NMC requested the adoption of ASME Code Case N-700, as an alternative to the rules for the selection of integrally welded attachments to their Reactor Vessel.

NMC believes that the proposed relief request is no longer necessary and is withdrawing the request. The following provides the basis for the withdrawal:

At PINGP, ASME Code Case N-509 was adopted during the third ten-year IS1 interval.

Table 2500-1 of ASME Code Case N-509 has note (3) applied to the Extent of Examination, which is applicable to Pressure Vessel Integrally Welded Attachments.

This note states that selected samples of integrally welded attachments shall be examined each inspection interval. There is no further discussion of an acceptable number of integrally welded attachments to be inspected except for multiple vessels of similar design, as stated in note (4) of the table. With only one Reactor Vessel per unit, note (4) does not apply.

Document Control Desk Page 2 ASME Code Case N-509 was accepted for use under Regulatory Guide (RG) 1.147, revision 12. With this acceptance, a stipulation that a minimum 10% sample of integrally welded attachments for each item in each code class per interval should be examined was added. e At PINGP, there are 5 integrally welded attachments on the Reactor Vessel of each unit. One integrally welded attachment of each Reactor Vessel has been inspected.

Therefore, 20% of the welded attachments have been inspected in the interval. This exceeds the minimum 10% stipulated in RG 1.147, revision 12, and therefore, the requirements of ASME Code Case N-509 have been met. ASME Code Case N-509 was approved for use with stipulations, under RG I. 147, revision 12. The stipulations of RG 1.147 were met.

Therefore, there is no need for relief request.

Summaw of Commitments This letter contains no new commitments and no revisions to existing commitments.

Thomas J. Palmisano Site Vice President, Prairie Island Nuclear Generating Plant Nuclear Management Company, LLC cc: Regional Administrator, Region Ill, USNRC Project Manager, Prairie Island Nuclear Plant, USNRC Resident Inspector, Prairie Island Nuclear Plant, USNRC Chief Boiler Inspector, State of Minnesota