ML20082N489
| ML20082N489 | |
| Person / Time | |
|---|---|
| Site: | Prairie Island  |
| Issue date: | 04/18/1995 |
| From: | Richard Anderson NORTHERN STATES POWER CO. |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| NUDOCS 9504250260 | |
| Download: ML20082N489 (4) | |
Text
s Northem States Power Company Prairie Island Nuclear Generating Plant 1717 Wakonada Dr. East Welch. Minnesota 55089 April 18, 1995 10 CFR Part 50 Section 50.55(a)
U S Nuclear Regulatory Commission Attn:
Document Control Desk Washington, DC 20555 PRAIRIE ISIAND NUCLEAR GENERATING PLANT Docket Nos. 50-282 License Nos. DPR-42 50-306 DPR-60 Request for Authorization to Utilize ASME Boiler & Pressure Vessel Code Case N-416-1 The purpose of this letter is to request NRC authorization to utilize ASME Boiler and Pressure Vessel Code Case N-416-1, " Alternative Pressure Test Requirement for Welded Repairs or Installation of Replacement Items by Welding, Class 1, 2, and 3,Section XI, Division 1" (attached), during the Prairie Island Third Ten Year Inservice Inspection Interval.
Code Case N-416-1 provides increased testing flexibility to the Owner, which should considerably reduce, if not eliminate, the need for the processing of relief requests associated with post weld repair / replacement hydrostatic testing.
This request is submitted pursuant to 10 CFR Part 50, Section 50.55a(a)(3) and Section 50.55a Footnote 6.
Code Case N-416-1 was approved by the ASME Code on February 15, 1994.
However, because it was only recently approved by ASME, the Code Case has not yet been endorsed in Regulatory Guide 1.147, " Inservice Inspection Code Case Acceptability ASME Section XI Division 1".
Until the Code Case is generically endorsed by the Regulatory Guide, specific NRC authorization is required before it can be used.
During the upcoming Unit 2 outage, NSP expects to require relief from the Code requirements for ASME hydrostatic testing following repair or replacement activities.
In each case, relief is necessary due to impracticality in testing, most commonly the inability to isolate the affected component from attached piping to allow a local hydrostatic test.
These situations are encountered during routine modification and maintenance activities, but can
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Page 2 also arise unexpectedly due to problems identified during outage inspection or testing activities.
Hardships are often encountered with hydrostatic testing performed in accordance with the Code.
For example, since hydrostatic test pressure would be higher than nominal operation pressure, hydrostatic pressure testing frequently requires significant effort to set up and perform. The need to use special equipment, such as temporary attachment of test pumps and gauges, and the need for individual valve lineups can cause the testing to be on critical path.
10 CFR Part 50, Section 50.55(a)(3) allows the use of proposed alternatives to Code requirements provided it can be demonstrated that the proposed alternatives would provide an acceptable level of quality and safety. ASME approval of Code Case N-416-1 satisfies this requirement, and the NRC may authorize its use in accordance with 10 CFR Part 50, Section 50.55a, Footnote 6.
The 1995 refueling outage for Unit 2 is scheduled to begin on October 23, 1995 and all repair / replacement hydrostatic testing would have to be completed prior to or during heatup at the end of the outage.
In lieu of submitting a specific relief request for all repair / replacement work that occurs during or following this outage, we intend to use Code Case N-416-1 to define post repair pressure testing requirements for any emergent ASME code repairs or replacements that may be required. NRC ataff review and authorization of this request is therefore needed as soon as practical, preferably before the May 13, 1995.
It is our plan to apply the code case to Unit 1 as well, although the next Unit i refueling is scheduled for January 1996, by which time the code case may be included in Reg Guide 1.147.
A similar request for authorization to use Code Case N-416-1 by Monticello Nuclear Generating Plant was approved by the NRC by letter dated November 2, 1994.
This letter contains no new NRC commitments.
" lease contact Jack Leveille (612-388-1121, Ext. 4662) if you require addicional information.
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Roger 0 Anderson Director l
Lic.ensing and Management Issues c: see next page N-416-1. DOC 1
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USNRC NORTHi!RN STATES POWER COMPANY April 18, 1995 Page 3 c: Regional Admfnistrator - Region III, NRC Senior Resident Inspector, NRC bM Project Manager, NRC J E Silberg
Attachment:
ASME Code Case N-416-1 M-416-1. DOC
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CASE o
N-416-1 CASES OF AS41E BOILER AND PRESSURE VESSEL. CODE
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Approval Date: February 15.1994 See Numeric Index for expiration and any reaffirmation dates.
Case N-416-1 placement items by welding, a system leakage test may Alternative Pressure Test Requirement for Welded be used provided the following requirements are met.
Repairs or Installation of Replacement Items by (a) NDE shall be performed in accordance with the Welding, Class I,2 and 3 methods and acceptance criteria of the applicable Sub-Section XI, Division I section of the 1992 Edition of Section III.
(b) Prior to or immediately urn retum to service, a visual examination (VT-2) sh J1 be performed in con-i Inquiry: What alternative pressure test may be per-junction with a system leakage test, using the 1992 Edi-formed in lieu of the hydrostatic pressure test required tion of Section XI, in accordance with para. IWA-5000, by para. IWA-4000 for welded repairs or installation of at nominal operating pressure and temperature.
replacement items by welding?
(c) Use of this Case shall be docur.iented on an NIS-2 Form.
Reply: It is the opinion of the Committee that in lieu If the previous version of this case were used to defer of performing the hydrostatic pressure test required by a Class 2 hydrostatic test, the deferred test may be elim-para. IWA-4000 for welded repairs or installation of re-inated when the requirements of this revision are met.
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