ML031130039

Relief, Visual Test Requirements for Insulated Pressure-retaining Bolted Connections, MB7315

ML031130039
Person / Time
Site:	Saint Lucie
Issue date:	04/21/2003
From:	Howe A NRC/NRR/DLPM/LPD2
To:	Stall J Florida Power & Light Co
Moroney B, NRR/DLPM, 415-3974
References
TAC MB7315
Download: ML031130039 (9)

Text

April 21, 2003 Mr. J. A. Stall Senior Vice President, Nuclear and Chief Nuclear Officer Florida Power and Light Company P.O. Box 14000 Juno Beach, Florida 33408-0420

SUBJECT:

SAINT LUCIE NUCLEAR PLANT, UNIT 2 - RELIEF REQUEST NO. 35 REGARDING EARLY USE OF ASME CODE CASE N-533-1 FOR SECOND 10-YEAR INSERVICE INSPECTION INTERVAL (TAC NO. MB7315)

Dear Mr. Stall:

By letter dated January 23, 2003, Florida Power and Light Company (the licensee) submitted Relief Request (RR) 35 for Saint Lucie Unit 2 (STL2), requesting relief from the visual test requirements for insulated pressure-retaining bolted connections set forth in the American Society of Mechanical Engineers (ASME) Code,Section XI, Article IWA-5242(a). In accordance with Title 10 of the Code Federal Regulation (10 CFR) Section 50.55a (Footnote 6) and 10 CFR 50.55a(a)(3)(i), the request proposed to implement ASME Code Case N-533-1, Alternative Requirements for VT-2 Visual Examination of Class 1, 2, and 3 Insulated Pressure Retaining Bolted Connections, as an alternative to the ASME Code,Section XI, Article IWA-5242(a). In addition to the code case requirements, the licensee proposed using a 4-hour hold time prior to inspection of insulated piping.

The U.S. Nuclear Regulatory Commission (NRC) staff has reviewed the licensees proposed alternative and has concluded that the use of Code Case N-533-1, including the use of a 4-hour hold time, provides an acceptable level of quality and safety for examination of the bolted connections of Class 1, 2, and 3 systems borated for controlling reactivity during pressure tests as prescribed by Section XI, Article IWA-5242(a). Therefore, pursuant to 10 CFR 50.55a(a)(3)(i), use of the code case is authorized until such time as Code Case N-533-1 is published in a future revision of Regulatory Guide 1.147, Inservice Inspection Code Case Acceptability, ASME Section XI, Division 1. At that time, if the licensee intends to continue implementing this code case, it must follow all provisions of Code Case N-533-1 with limitations or conditions specified in RG 1.147, if any. This authorization is for the remainder of the second 10-year inservice inspection interval at STL2, which began August 8, 1993, and ends August 7, 2003.

Mr. J. A. Stall Further details on the bases for the NRC staffs conclusions are contained in the enclosed safety evaluation. If you have any questions regarding this issue, please contact Eva Brown at (301) 415-2315 or Brendan Moroney at (301) 415-3974.

Sincerely,

/RA by M.Marshall Acting for/

Allen G. Howe, Chief, Section 2 Project Directorate II Division of Licensing Project Management Office of Nuclear Reactor Regulation Docket No. 50-389

Enclosure:

Safety Evaluation cc: See next page

ML031130039 OFFICE PDII-2/Intern PDII-2/PM PDII-2/PM PDII-2/LA OGC EMCB/SC PDII-2/SC NAME MDudek BMoroney EBrown BClayton TChan MMarshall for AHowe DATE 4/9/03 4/9/03 4/7/03 4/7/03 4/21/03 memo 3/24/03 4/21/03 Mr. J. A. Stall ST. LUCIE PLANT Florida Power and Light Company cc:

Senior Resident Inspector Mr. R. E. Rose St. Lucie Plant Plant General Manager U.S. Nuclear Regulatory Commission St. Lucie Nuclear Plant P.O. Box 6090 6351 South Ocean Drive Jensen Beach, Florida 34957 Jensen Beach, Florida 34957 Craig Fugate, Director Division of Emergency Preparedness Licensing Manager Department of Community Affairs St. Lucie Nuclear Plant 2740 Centerview Drive 6351 South Ocean Drive Tallahassee, Florida 32399-2100 Jensen Beach, Florida 34957 M. S. Ross, Attorney Florida Power & Light Company Vice President, Nuclear Operations Support P.O. Box 14000 Florida Power & Light Company Juno Beach, FL 33408-0420 P.O. Box 14000 Juno Beach, FL 33408-0420 Mr. Douglas Anderson County Administrator Mr. Rajiv S. Kundalkar St. Lucie County Vice President - Nuclear Engineering 2300 Virginia Avenue Florida Power & Light Company Fort Pierce, Florida 34982 P.O. Box 14000 Juno Beach, FL 33408-0420 Mr. William A. Passetti, Chief Department of Health Mr. J. Kammel Bureau of Radiation Control Radiological Emergency 2020 Capital Circle, SE, Bin #C21 Planning Administrator Tallahassee, Florida 32399-1741 Department of Public Safety 6000 SE. Tower Drive Site Vice President Stuart, Florida 34997 St. Lucie Nuclear Plant 6351 South Ocean Drive Jensen Beach, Florida 34957

SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION INSERVICE INSPECTION PROGRAM RELIEF REQUEST NO. 35 FLORIDA POWER AND LIGHT SAINT LUCIE NUCLEAR PLANT, UNIT 2 DOCKET NO. 50-389

1.0 INTRODUCTION

By a letter dated January 23, 2003, Florida Power and Light Company (FPL, the licensee) submitted Relief Request (RR) 35 for Saint Lucie Unit 2 (STL2). The licensee requested relief from the visual test requirements (i.e., VT-2 visual examination) of pressure-retaining bolted connections set forth in American Society of Mechanical Engineers (ASME) Code (Code),

Section XI, Article IWA-5242(a), pursuant to Title 10 of the Code of Federal Regulations (10 CFR) Section 50.55a(a)(3)(i) and proposed alternative VT-2 visual examination requirements which have not been authorized by the U.S. Nuclear Regulatory Commission (NRC) staff. FPL proposed to use Code Case N-533-1 dated February 26, 1999, entitled Alternative Requirements for VT-2 Visual Examination of Class 1, 2, and 3 Insulated Pressure Retaining Bolted Connections as an alternative to the IWA-5242(a) requirements. Code Case N-533-1 provides alternative criteria for the inspection of ASME Class 1, 2, and 3 systems borated for the purpose of controlling reactivity. The subject RR is for the remainder of the second 10-year inservice inspection (ISI) interval at STL2, which began August 8, 1993, and ends August 7, 2003.

2.0 REGULATORY EVALUATION

As stated in 10 CFR 50.55a(a)(3), alternatives to the requirements of paragraph (g) of this section may be used when authorized by the NRC, if (i) the proposed alternatives would provide an acceptable level of quality and safety, or (ii) compliance with the specified requirements of this section would result in hardship or unusual difficulty without a compensating increase in the level of quality and safety.

Pursuant to 10 CFR 50.55a(g)(4), ASME Class 1, 2, and 3 components (including supports) shall meet the requirements, except the design and access provisions and the pre-service examination requirements, set forth in the Code,Section XI, Rules for ISI of Nuclear Power Plant Components, to the extent practical within the limitations of design, geometry, and materials of construction of the components. The regulations require that inservice examination of components and system pressure tests conducted during the first 10-year interval and Enclosure

subsequent intervals comply with the requirements in the latest edition and addenda of Section XI of the Code incorporated by reference in 10 CFR 50.55a(b) 12 months prior to the start of the 120-month interval, subject to the limitations and modifications listed therein.

The applicable Code of record for the second 10-year ISI interval for STL2 is the 1989 Edition of the Code,Section XI, no addenda.

3.0 TECHNICAL EVALUATION

By a letter dated January 23, 2003, the licensee requested approval to use an alternative VT-2 examination method as prescribed within the guidelines of the ASME Code Case N-533-1, Alternative Requirements for VT-2 Visual Examination of Class 1, 2, and 3 Insulated Pressure Retaining Bolted Connections.

3.1 RELIEF REQUEST NO. 35, USE OF ASME CODE CASE N-533-1 3.1.1 Component Identification STL2, Insulated Pressure Retaining Bolted Connections of Class 1, 2, and 3 Systems 3.1.2 Code Requirements for which Relief is Requested ASME Code Section XI, 1989 Edition with no addenda, Article IWA-5242(a), requires that for systems borated for controlling reactivity, insulation shall be removed from pressure retaining bolted connections during system pressure tests.

3.1.3 Licensees Proposed Alternative to Code Pursuant to 10 CFR 50.55a(a)(3)(i), FPL requested an alternative to the Code required VT-2 visual examination requirements for bolted connections set forth in IWA-5242(a). FPL indicated their intent to utilize the alternative requirements of ASME Code Case N-533-1, Alternative Requirements for VT-2 Visual Examination of Class 1, 2, and 3 Insulated Pressure-Retaining Bolted Connections,Section XI, Division 1.

Since system pressure tests are typically conducted at elevated temperatures and pressures, performance of the examinations in accordance with IWA-5242(a) involves physical challenges and concerns for personnel safety. Code Case N-533-1 provides the following alternatives to the IWA-5242(a) requirement for removing insulation from Class 1, 2 and 3 pressure-retaining bolted connections to perform a VT-2 visual examination:

(a) A system pressure test and VT-2 visual examination shall be performed each refueling outage for Class 1 connections and each period for Class 2 and 3 connections without removal of insulation.

(b) The insulation shall be removed from the bolted connection, each refueling outage for Class 1 connections and each period for Classes 2 and 3 connections, and a VT-2 visual examination shall be performed. The connection is not required to be pressurized. Any evidence of leakage shall be evaluated in accordance with IWA-5250.

FPL has proposed to perform VT-2 visual examinations in accordance with Code Case N-533-1. Also, in addition to the requirements of paragraph (a) of Code Case N-533-1, FPL stated that the system pressure test and VT-2 visual examination with the insulation installed on bolted joints at normal operating pressure and temperature would include a 4-hour hold time, as required.

3.1.4 Licensees Basis for Relief The licensee stated that the proposed alternative provides and acceptable level of quality and safety, and permits the Section XI examinations to be performed while components are at safe operating pressures and temperatures.

The licensee stated that ambient conditions during the installation of insulation after VT-2 visual examinations at normal operating pressure and normal operating temperature (NOP/NOT) require heat stress work restrictions. Containment entries at NOP/NOT are physically demanding on personnel due to the adverse heat environment. Stay times for personnel in many areas are less than 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> and would require multiple containment entries to complete the examination activities. Ambient temperatures range from 95 to 120 degrees Fahrenheit (EF).

Reinstalling contaminated insulating material under adverse conditions (i.e., to piping that is at 2250 pounds per square inch gauge and greater than 500EF) would negatively impact total personnel contamination and expose personnel to unnecessary safety risk. Additionally, increased dose would be accumulated due to reduced examination efficiency as a result of the necessity to wear special protective equipment (e.g., ice vests).

The licensee also indicated that added physical and heat stress limitations would be placed on personnel when the plant is in Mode 3, with the equipment hatch secured. In Mode 3, the removal of scaffolding from containment would be through the reactor containment building personnel hatch instead of the equipment hatch, causing additional difficulty.

Further, the licensee stated, in accordance with Code Case N-533-1, that examinations for evidence of bolt degradation and leakage will be performed by having examiners look for boric acid residue, which accumulates around leakage sites. These examinations will be performed while components are at safe operating pressures and temperatures providing the required acceptable level of quality and safety and will, therefore, meet the intent of Section XI, IWA-5240.

The submittal indicates that should Code Case N-533-1 be referenced in a future revision of Regulatory Guide (RG) 1.147, FPL would implement any limitations stated in the RG.

3.1.5 Evaluation Code Case N-533-1 was approved for use by ASME on February 26, 1999, as an alternative to the Code requirements of IWA-5242(a). The Code Case determined that evaluations and repairs could be performed without the need to bring the plant to a cold shutdown condition since the VT-2 visual examinations are normally performed at normal operating pressure and temperature during startup. The approach includes a system pressure test and a VT-2 visual examination, which will be performed during each outage for Class 1 systems and during each

period for Class 2 and 3 systems. The licensee has indicated that, in addition to the code case provisions, it will utilize a 4-hour hold time for the system pressure test, and that the 4-hour hold time should allow any leakage to penetrate the insulation and provide a means of detecting any significant leakage with the insulation in place.

The NRC staff reviewed Code Case N-533-1 to determine whether the alternative proposed to ensure the leak-tight integrity of systems borated for the purpose of controlling reactivity was acceptable. The approach would include a system pressure test and a VT-2 visual examination, which would be performed each period for Class 2 and 3 systems and each refueling outage for Class 1 systems. By removing the insulation each refueling outage for Class 1 systems and each inspection period for Class 2 and 3 systems, the licensee should be able to detect minor leakage indicated by the presence of boric acid crystals or residue. The NRC staff finds the utilization of a minimum 4-hour hold time for the system pressure test should provide an adequate means of detecting any significant leakage with the insulation in place. Additionally, this two-step approach should provide reasonable assurance of integrity for the pressure-retaining bolted connections in Class 1, 2 and 3 systems.

Based on the above discussion, the NRC staff has determined that the alternative proposed in Code Case N-533-1, plus the licensees proposed use of a 4-hour hold time, provides an acceptable level of quality and safety for examination of the bolted connections on systems borated for controlling reactivity during system pressure tests, as prescribed by Section XI, Article IWA 5242(a), and satisfies the criteria of 10 CFR 50.55a(a)(3)(i).

4.0 CONCLUSION

Based on the above, the licensees proposed alternative is authorized pursuant to 10 CFR 50.55a(a)(3)(i) until such time as Code Case N-533-1 is referenced in a future revision of RG 1.147, Inservice Inspection Code Case Acceptability, ASME Section XI, Division 1. At that time, if the licensee wishes to continue implementing the code case, it must follow all provisions of Code Case N-533-1 with limitations and conditions specified in the RG, if any. This authorization is for the remainder of the second 10-year ISI interval at STL2, which began August 8, 1993, and ends August 7, 2003. All other ASME Code,Section XI requirements for which relief was not specifically requested and approved in this relief request remain applicable, including third-party review by the Authorized Nuclear Inservice Inspector.

Principal Contributor: Eric G. Reichelt, NRR Date: April 21, 2003