ML17241A364

Submits Supplement to Relief Request 24 with Info Requested by Nrc.In Addition Relief Request 24 Is Identical to St Lucie Unit 1 Relief Request 4 for Third ISI Interval Being Supplemented by FPL Ltr L-99-139

ML17241A364
Person / Time
Site:	Saint Lucie
Issue date:	06/14/1999
From:	Stall J FLORIDA POWER & LIGHT CO.
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
L-99-141, NUDOCS 9906180019
Download: ML17241A364 (7)

Text

REGULATORY INFORMATION DISTRIBUTION SYSTEM (RXDS)

ACCESSION NBR:9906180019 DOC.DATE: 99/06/14 NOTARIZED: NO DOCKET

, FACIL:50-389 St. Lucie Plant, Unit 2, Florida Power 8 Light Co. 05000389 RUTH~NAME'.> AUTHOR AFFILIATION STALL,J.A. Florida Power &. Light Co.

REC1P.NAME RECIPXENT AFFILIATION Records Management Branch (Document Control Desk)

SUBJECT:

Submits supplement to relief request 24 with info requested by NRC.In addition relief request 24 is identical to St Lucie Unit 1 relief request 4 for third ISI interval being supplemented by FPL ltr L-99-139.

DISTRIBUTION CODE: A047D COPIES RECEIVED:LTR ENCL SIZE:

TITLE: OR Submittal: Inservice/Testing/Relief from ASME Code - GL- 9-04 E

NOTES:

RECIPIENT COPIES RECIPIENT COPIES ID CODE/NAME LTTR ENCL ID CODE/NAME LTTR ENCL 0 LPD2-2 LA 1 1 LPD2-2 PD 1 1 GLEAVES,W 1 1 R INTERNAL: ACRS 1 1 FILE CENTE 01 1 1 NRR/DE/EMEB 1 1 OK'i -XZST 1 - 1 OGC/RP 1 0 RES/DET/EIB 1 1 RES/DET/EMMEB 1 1 EXTERNAL: LITCO A'%EMERSON 1 1 NOAC 1 1 NRC PDR 1 1 D

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'E NOTE TO ALL "RIDS" RECIPIENTS:

PLEASE HELP US TO REDUCE WASTE. TO HAVE YOUR NAME OR ORGANIZATION REMOVED FROM DISTRIBUTION LISTS OR REDUCE THE NUMBER OF COPIES RECEIVED BY YOU OR YOUR ORGANIZATION, CONTACT THE DOCUMENT CONTROL DESK (DCD) ON EXTENSION 415"2083 TOTAL NUMBER OF COPIES REQUIRED: LTTR 13 ENCL 12

Florida Power 5 Light Company, 6351 S. Ocean Drive, Jensen Beach, FL 34957 June 14, 1999 L-99-141 10 CFR 50.55a 10 CFR 50.4 US Nuclear Regulatory Commission ATTN: Document Control Desk Washington, DC 20555 RE: St. Lucie Unit 2 Docket No. 50-389 Second Ten-Year In-Service-Inspection Interval Revised Relief R uest 24 The second ten-year in-service inspection (ISI) interval for St. Lucie Unit 2 began on August 8, 1993. Florida Power & Light Company (FPL) submitted the ISI program relief requests (R/R) 23 and 24 by letter L-99-55 on March 16, 1999. R/R 24 proposes alternatives to the requirements of IWA-5250(a)(2) for the remainder of the second interval. The proposed alternatives will be used for the performance of the required examinations of Class 1, 2, and 3 pressure retaining bolted connections as specified in the 1989 Edition of ASME Section XI. In a telephone conference on May 10, 1999, the NRC project manager for St. Lucie notified FPL that R/R 24 would require additional information and therefore was not being approved, as submitted.

The purpose of this letter is to supplement R/R 24 with. the information requested by the NRC.

In addition, R/R 24 is identical to St. Lucie Unit 1 R/R 4 for the third interval being supplemented by FPL letter L-99-139. NRC review and approval are requested by August 1999 to support planning for the Spring 2000 Unit 2 refueling outage (SL2-12). Please contact us immediately should you require any additional clarifications.

Very truly yours, J. A. Stall Site Vice President St. Lucie Plant Enclosure cc: Regional Administrator, USNRC, Region II Senior Resident Inspector, USNRC, St. Lucie Plant 9906i800i9 990614 PDR ADOCK 05000389 8 PDR M gj.,r, Q an FPL Group company

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St. Lucie Unit 2 Decket No. 50-389 L-99-141 Enclosure Page 1 St. Lucie Unit 2 SECOND INSPECTION INTERVAL RELIEF REQUEST NUMBER 24 A. COMPONENT IDENTIFICATION:

Class 1, 2, and 3 Pressure Retaining Bolted Connections at Florida Power and Light's (FPL) St.

Lucie Unit 2.

B. EXAMINATIONREQUIREMENT:

Rules for Inseivice Inspection of Nuclear Power Plant Components,Section XI, 1989 Edition IWA-5250(a)(2) if leakage occurs at a bolted connection, the bolting shall be removed, VT-3 visually examined for corrosion, and evaluated in accordance with IWA-3100.

C. RELIEF REQUESTED'.

Pursuant to 10 CFR 50.55a(a)(3)(i), FPL requests relief from the code requirement of removing and performing a VT-3 visual examination on bolting when leakage is observed at a bolted connection during a system pressure test. Additionally, when required, FPL proposes to perform a VT-1 visual examination of the affected bolting in lieu of the specified VT-3 examination.

BASIS FOR RELIEF:

The requirement to remove all bolting from a bolted connection to check for degradation is a burden. This requirement does not take into account the corrosiveness of the fluid, the material of the leaking component, the type, and location of the leakage, and the history of material degradation in a similar environment. Additional examinations are performed by system engineers during routine surveillance required by plant Technical Specifications and procedures.

Previous corrective actions are not taken into account. The 1992 and later Editions of ASME Section XI changed the IWA-5250 requirements to allow the removal of the bolt closest to the source of leakage, reducing the number of bolts to be examined.

ASME Code interpretation XI-1-92-01 states that new bolting or bolting that has received a visual examination prior to installation and has not been inservice does not have to be evaluated in accordance with this section. This is recognition by the Code that leakage at this point would be considered a maintenance item, and one in which the requirements of IWA-5250 (a)(2) do not apply.

Removal of pressure retaining bolting at mechanical connections for VT-3 visual examination and subsequent evaluation in locations where leakage has been identified is not always the most prudent course of action to determine the acceptability of the bolting. This is a task that could easily cause more harm than good. Many bolted connections are studs threaded into a component such as a valve or pump. Removal of these studs can be difficult due to the length of time they have been installed. Large studs, such as those found on the Reactor Coolant Pumps, pose additional problems with removal. Damage to the pump casings can occur if substantial torque is required to remove a stud.

The Code requirement to remove, examine, and evaluate bolting in this situation does not allow the Owner to consider other factors which may indicate the acceptability of mechanical joint bolting. FPL considers this requirement to be unnecessarily prescriptive and restrictive.

Other factors which should be considered when evaluating bolting acceptability when leakage has been identified at a mechanical joint include, but should not be limited to: joint bolting materials, service age of joint bolting materials, location of the leakage, history of leakage at the joint, evidence of corrosion with the joint assembled, and corrosiveness of process fluid.

St. Lucie Unit 2 Docket No. 50-389 I 99-141 Enclosure Page 2 St. Lucie Unit 2 SECOND INSPECTION INTERVAL RELIEF REQUEST NUMBER 24 e

ASME Section XI is written to primarily address examinations and testing during periods of plant or system shutdown. No guidance is given to address components that are examined or tested while the plant or system is in sewice. However, many Code Class 3 and a few Code Class 2 systems are pressure tested, including VT-2 visually examined, utilizing the "inservice test" requirements of IWA-5000.

Performance of the test while the system is inservice may identify leakage at a bolted connection that, upon evaluation, may conclude that the joint's structural integrity and pressure retaining ability is not challenged. It would not be prudent to negatively impact safety system availability by removing the system from service to address a leak that does not challenge the system's ability to perform its safety function.

In addition, a situation frequently encountered at commercial nuclear plants such as St. Lucie, is the complete replacement of bolting materials (studs, bolts, nuts, washers, etc.) at mechanical joints during plant outages. When the associated system process piping is pressurized during plant start-up, leakage is identified at these joints. The root cause of this leakage is most often due to thermal expansion of the piping and bolting materials at the joint and subsequent process fluid seepage at the joint gasket. Proper retorquing of the joint bolting, in most cases, stops the leakage. Removal of any of the joint bolting to evaluate for corrosion would be unwarranted in this situation due to new condition of the bolting materials.

Later editions of the Code have realized the problems inherent in removal of all bolting. The wording of the Code has been changed to avoid removing of all bolting to perform an evaluation.

The proposed alternatives are consistent with Code Case N 566-1 that was approved by the Code Committee on February 15, 1999.

ALTERNATIVEEXAMINATIONS:

When FPL finds leakage at bolted connections by VT-2 visual examination during system pressure testing, as an alternative to the requirements of IWA 5250(a)(2), either the requirements of (a) or (b) below will be met.

(a). The leakage will be stopped and the bolting and component material will be evaluated for joint integrity as described in (c) below.

(b). If the leakage is not stopped, the joint will be evaluated in accordance with IWB-3142.4 for joint integrity. This evaluation will include the considerations listed in (c) below. The evaluation will be submitted to the authority having jurisdiction in accordance with IWB-3144.

(c). The evaluation for (a) and (b) above is to determine the susceptibility of the bolting to corrosion and failure. This evaluation will, at a minimum, consider the following factors:

1. The number and service age of the bolting

2. Bolt and component material

3. Corrosiveness of process fluid

4. Leakage location and system function

5. Leakage history at connection or other system components

6. Visual evidence of corrosion at connection (while connection is assembled)

St. Lucie Unit 2 Dpcket No. 50-389 L-99-141 Enclosure Page 3 St. Lucie Unit 2 SECOND INSPECTION INTERVAL RELIEF REQUEST NUMBER 24 When the pressure test is performed with the system in service or required by the Technical Specifications to be operable, and the bolting is susceptible to corrosion, the evaluation shall address the connection's structural integrity until the next component/system outage of sufficient duration. If the evaluation concludes that the system can perform its safety related function, removal of the bolt closest to the leakage and VT-1 visual examination and evaluation in accordance with IWB-3517 of the bolt will be performed when the system of component is taken out of service for a sufficient duration for accomplishment of the system maintenance activities.

When the removed bolt shows evidence of unacceptable degradation, additional affected bolting shall be removed, VT-1 examined, and evaluated in accordance with IWB-3517, or the affected bolting shall be replaced.

For bolting that is susceptible to corrosion, and when the initial evaluation indicates that the connection cannot conclusively perform its safety function until the next component/system outage of sufficient duration, the bolt dosest to the source of leakage will be removed, receive a VT-1 visual examination, and be evaluated in accordance with IWB-3517. When the removed bolt shows evidence of unacceptable degradation, additional affected bolting shall be removed, VT-1 examined, and evaluated in accordance with IWB-3517, or the affected bolting shall be replaced.

F. IMPLEMENTATIONSCHEDULE:

Second Inservice Inspection Inteival G. ATTACHMENTS TO THE RELIEF:

None