ML18065A417

Requests Approval of Code Case N-533 for Use of Alternative Requirements of VT-2 Visual Exam for Class 1 Insulated Pressure Retaining Bolted Connections

ML18065A417
Person / Time
Site:	Palisades
Issue date:	01/18/1996
From:	Smedley R CONSUMERS ENERGY CO. (FORMERLY CONSUMERS POWER CO.)
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
NUDOCS 9601230150
Download: ML18065A417 (5)

Text

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consumers Power POW ERi Nii lllllCHlliAN"S PROliRESS Palisades Nuclear Plant: 27780 Blue Star Memorial Highway, Covert, Ml 49043 January 18, 1996 US Nuclear Regulatory Commission Document Control Desk Washington, DC 20555 I'

DOCKET 50-255 - LICENSE DPR PALISADES PLANT REQUEST FOR APPROVAL OF CODE CASE N-533 FOR USE OF ALTERNATIVE REQUIREMENTS OF VT-2 VISUAL EXAMINATION FOR CLASS 1 INSULATED PRESSURE RETAINING BOLTED CONNECTIONS In accordance with 10CFR50.55a(a)(3), NRC approval is requested for the use of Code Case N-533, which involves the use of alternative requirements for VT-2 visual examination of Class 1 insulated pressure retaining bolted connections. This approval is requested until Code Case N-533 is included in Regulatory Guide 1.147, lnservice Inspection Code Case Acceptability - ASME Section XI Division 1.

Implementation of this code case, when approved by the NRC staff, will begin during our 1996 refueling outage (currently scheduled to begin November 2, 1996). Use of this Code Case will reduce the schedule impact and personnel hazards associated with pressure testing of Class 1 systems.

Approval of this request will affect the system leakage testing that Palisades is required to perform during the 1996 refueling outage. If use of Code Case N-533 is not approved, system leakage testing would be required after plant heatup and pressurization to normal operating pressure. During the leak test, insulation would be required to be removed from all bolted connections such as coolant pump casings, check valve bonnets, reactor flange, and related components. These requirements cause examinations and insulation restorations to be performed under hot conditions with personnel working in close proximity to equipment which is operating at 9601230150 960118 c

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approximately 500 °F. Personnel hazards such as heat stress, elevated work areas, and extended times in radiation environments would be encountered.

Code Case N..,533 would allow examination and reinsulation of bolted connections during cold plant conditions. The requirements of Code Case N-533 are:

1.

A system pressure test and VT-2 visual examination shall be performed each refueling outage without insulation removal.

2.

Each refueling outage, the insulation shall be removed from the bolted connection and a VT-2 visual examination performed. The system is not required to be pressurized. Any evidence of leakage shall be evaluated in accordance with ASME Section XI, IWA-5250.

Pursuant to 1 OCFR50.55a(a)(3) and the justification provided in Attachment A, we therefore request that the Code Case N-533 be approved as an acceptable alternative to current NRC requirements.

SUMMARY

OF COMMITMENTS This letter contains no new commitments and no revisions to existing commitments.,

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Richard W Smedley

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Manager, Licensing CC Administrator, Region Ill, USNRC Project Manager, NRR, USNRC NRC Resident Inspector - Palisades Attachment

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ATTACHMENT CONSUMERS POWER COMPANY PALISADES PLANT DOCKET 50-255 REQUEST FOR APPROVAL OF CODE CASE N-533 FOR USE OF ALTERNATIVE REQUIREMENTS OF VT-2 VISUAL EXAMINATION FOR CLASS 1 INSULATED PRESSURE RETAINING BOLTED CONNECTIONS 2 Pages

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JUSTIFICATION FOR USE OF CODE CASE N-533 Code Classes:

Subject:

1 Alternative Requirements for VT-2 Visual Examination of Class 1 Insulated Pressure Retaining Bolted ConnectionsSection XI, Division 1 Component Numbers:

All Class 1 bolted connections subject to System Leakage Testing in accordance with IWA-5211 (a).

Code Requirement:

The 1983 Edition, Summer 83 Addenda of ASME Section XI, IWA-5242(a) states "The visual examination VT-2 may be conducted without the removal of insulation by examining the accessible and exposed surfaces and joints of the insulation." This requirement applied to Palisades during the second lnservice lnspection(ISI) interval which expired at the conclusion of the 1995 refueling outage.

During the third ISi interval, the 1989 Edition of ASME Section XI applies to Palisades. Section IWA-5211 (a) of the 1989 Edition requires a System Leakage Test (which includes a VT-2 visual examination) at nominal operating pressure after opening and closing a component in the system; and, Section IWA-5242(a) of that Edition requires, for systems borated for purposes of reactivity control, that insulation be removed from pressure retaining bolted connections before performing visual examination VT-2.

Therefore, if no alternative is applied, the System Leakage Test for the Primary Coolant System (PCS) will have to be performed on the system after the insulation has been removed from all the bolted connections, such as on the Primary Coolant

• Pumps, check valve bonnets, the reactor head flange, etc. The insulation would then have to be reinstalled after completion of the test and while the system is in the hot and pressurized condition unless valuable outage time is expended waiting for the system to cool down. This would also require an unnecessary additional heating cycle on the PCS.

Proposed Alternative:

Following opening and reclosing of components in the PCS the following alternative requirements will be met in lieu of the requirement of IWA-5242(a) to remove insulation from Class 1 pressure retaining bolted connections to perform a VT-2 visual examination.

1

JUSTIFICATION FOR USE OF CODE CASE N-533

1.

A system pressure test and VT-2 visual examination shall be performed each refueling outage without insulation removal.

2.

Each refueling outage the insulation shall be removed from the bolted.

connection, 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.

These requirements are specified in Nuclear Code Case N-533 as approved by the Board of Nuclear Codes and Standards.

Basis for Justification:

Pursuant to 1 OCFR50.55a(a)(3){i), the proposed alternatives provide an acceptable level of quality and safety.

When the plant is at hot shutdown, a system pressure test and VT-2 visual examination will be completed with insulation installed on bolted connections. This test and examination philosophy is consistent with the lnservice Inspection Pressure Test Program which was in place during the second ISi.interval. These examinations, in conjunction with routine monitoring of Primary Coolant System (PCS) leakage, will provide adequate assurance of PCS integrity. The significant burden imposed by examination of hot, uninsulated components and subsequent reinsulation is not commensurate with their marginal contribution to plant safety.

The proposed alternative will reduce exposure to personnel hazards, such as, heat stress, elevated work areas, and radiation environments. Conduct of examinations and installation of insulation during hot conditions would require examiners to access equipment which is operating at approximately 500°F, exposing examiners to heat stress and burn hazards. Additionally, examination of the Primary Coolant System (PCS) and Engineered Safeguards System (ESS) bolted connections would require access to the Containment Building when floor plugs have been removed for operation exposing examiners to elevated work area hazards. Additional dose would be accumulated and examination efficiency would b~ decreased due to the necessity to wear special protective equipment (eg, ice vests) and to limit stay times in hot environments.

The proposed alternative will take advantage of outage activities which, by their nature, resultin disassembly and restoration of bolted connections. The proposed

. alternative will allow examination to take place during the course of these outage activities and avoid redundant efforts. By avoiding redundant efforts, plant resources can be used to complete other safety significant tasks.

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