ML20070C639

Forwards ISI Second Interval Relief Request 94-005 from 1986 (Unit 1) & 1989 (Unit 2) Edition of Section XI,IWA-5242, Insulated Components & IWA-5250,corrective Measures

ML20070C639
Person / Time
Site:	Mcguire, McGuire
Issue date:	06/24/1994
From:	Mcmeekin T DUKE POWER CO.
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
NUDOCS 9407060192
Download: ML20070C639 (9)

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Duke 1% er O>mpany T C McMWn M:Gwn Nudear Generahon inanment Vtce hevdent I}iU9 Hagm Terry Rwd (MGOI\T) (IN ?754800 lluntenns, hC 2WSXh5 (704$754%9 Fat DUKE POWER June 24, 1994 Document Control Desk U.S. Nuclear Regulatory Commission Wachington, D.C. 20555

Subject:

McGuire Nuclear Station McGuire Nuclear Station, Units 1 and 2 Docket Nos. 50-369 50-370 Section XI, Inservice Inspection Second Interval, Unito 1 and 2 Rollef Request,94-005 g Dear Sirl Pursuant to Ju CFR50.55a (g) (5) (iii), I am cubmitting the attached relief requev .for NRC review and approval. This request for relief from ASME Code requirements involves both the 1986 (Unit 1) and 1989 (Unit 2) Edition of Section XI, IWA5242, Insulated Components snd IWA-5250, Corrective Measures. The bolted connections under consideration include pipe flange to pipe flange joints as well as other component configurations such as valve bonnet to body connections. Attachment 1 discusses INA-5242 and the proposed Alternate Method while Attachment 2 addresses IWA-5250 requirements.

Should there be any questions regarding this matter, please contact John M. Wacham at (704) 875-4181.

Very truly yours, t r/ ,, g -

T. C. McMeekin _

w' 9407060192 940624 PDR ADOCK 05000369 D PDR l

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U.S. Nuclear Regulatory Commission June 24 1994 page 2 xc: Mr. S.J. Ebneter Admin'.strator, Region II U.S. ~1uclear Regulatory Commission 101 Parietta St., NW, Suite 2900 Atlanta, Ga. 30323 Mr. Victor Nernes U.S. Nuclear Regulatory Commission office of Nuclear Reactor Regulation Washington, D.C. 20555 Mr. George .4axwell Senior NRC Resident Inspector, McGuire McGuire Nuclear Station l

DUKE POWER COMPANY Request for Relief From Inservice Inspection Requirement ATTACHMENT 1 Stationt McGuire Nuclear Station Unit 1 and 2 Reference Code (s): 1986 Edition of Section XI for Unit 1 1989 Edition of Section XI for Unit 2

1. Component for which exemption is requested:

A. 5.me and Identification Number:

Insulated bolted connections in ASME Class 1, 2, and 3 Systems borated for reactivity control within the scope of a system pressure test. Bolted connections include pipe flange to pipe flange joints as well as other component connections such as valve bonnet to valve body.

B. Function:

These bolted connections provide a pressure boundary function for ASME Class 1, 2, and 3 systems.

C. ASME Section XI Code Case:

None D. Construction Code and Class (If Applicable):

ASME Section III, Class 1, 2 and 3 E. Valve Category (If Applicable):

Not applicable F. Attachments (list) or

References:

None II. Reference Code Requirement from which relief in desired:

ASME Boiler and Pressure Vessel Code,Section VI, 1986 and 1989 Editions, Article IWA-5242.

l III. Basis for Hoquesting Relief The ASME Boiler and Pressure Vessel Code,Section XI, 1986 and 1989 Edition, Article IWA-5242, Insulated Components states in part:

"(a) For systems borated for the purpose of controlling reactivity, insulation shall be removed from pressure retaining bolted connections for visual examination VT-2. For other componenta, visual examination VT-2 may be conducted without the removal of insulation by examining the accessible and exposed surfacas and joints of the insulation...."

The purpose of this requirement is to verify that no unacceptable pressure boundary degradation has occurred to the bolting connection covered by the insulation. '

This relief is requested as a result of the development of an alternative inspection methodology which is equivalent in determining condition of the bolted connection while increasing the safety of station personnel.

The burden imposed by IWA-5242 (a) that will be relieved by this request is as follows:

Current ASME XI requirements involving inspection of bolted connections increase the probability of personnel burn accidents. Susceptibility to the increased risk results from rising containment temperature as a result of the removal of the insulation for inspecticn of ASME Class i bolted connections at high system pressure and temperature.

Containment temperatures rise as a result of the removal of the insulation and could affect the integrity of the Ice Condenser by sublimation of a portion of the ice. This mandates that the insulation remain in place until just prior to the VT-2, thus placing plant personnel in a rigorous environment with the relatively high potential for burn accidents.

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IV. Alternatu Examinat ion :

'lhe proposed alte> native methodology will meet the intent of the IWA-5242 requirement while avoiding or limiting the imposed burden as stated above. The Alternative Examination will be applied at the discretion of station personnel for each ppecific bolted conaection.

(1) All bolted connections within the scope of the planned system pressure testing will be identified.

(2) The identified connections will be compared with the bolted connections scbeduled for disassembly during the subject outage.

(3) The bolted connections which are not scheduled for disassembly 6; ring the outage will have the insulation removed and will be inspected for borated water leakage.

residue. The inspection rea tits and date of inspection for i the specific connection will be documented in the station work management system.

(4) If a connection is found to be a source cf leakage, the ccnnection will be disassembled and the bolting inspected during the subject outage.

(5) The insulation will be replaced on al'. bolted connections.

(6) System pressure testing aunc 1-t u with the outage will be coaducted as norms'ly caneduled. The insulated bolted connections on be. rated systems will treated as "other componorts" as apecified in IWA-5242 (a).

This proposed Alternative Examination procedure will provide an acceptable level of quality and safety. As per code, the insulation is removed from borated systems because the Owner has no evidence of the condition of bolted connection. . With the 3 Alternative Examination procedure, station personnel can document the bolting is without visually detectable degradation prior to Mode 3 (operating pressure and temperature with-a suberitical core) Unit restart. Therefore the r&toval of the insulation will not be required prior to pressure testing since the owner knows the condition.of the insulated bolted connection 1.

By implementing the proposed Alternative Examination procedure, there is a signifiaant d- :- se in the risk associated with burn injuries to station personnel, but no decrease in the quality of Nuclear Safety.

V. Implomontation Schedule The proposed Alternative Examination, if found acceptabj e, will be implemented during refueling outage End of Cycle (EOC) 9 for Units 1 and 2.

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DUKE POWER COMPANY Request for Relief From Inservice Inspection Requiremont ATTACHMENT 2 Station: McGuire Nuclear Statior Un i t. : 1 and 2 Reference Code (s): 1986 Edition of Section XI for Unit 1 1989 Edition of Section XI for Unit 2

1. Component for which exemption is requested:

A. Name and Identification Number:

Bolted connections in ASME Class 1, 2, and 3 Systems within the scope of a system pressure test. Bolted connections include pipe flange to pipe flange joints as well as other component connections such as valve bonnet to valve body.

B. Function:

I These bolted connections provide a pressure bounder function for ASME Class 1, 2, and 3 systems.

C. ASME Section XI Code Case: 3 None D. Construction Code and Claos (If Applicable)!

ASME Soetion III, Class 1, 2, and 3

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E. Valve Category (If Applicable):

Not applicable F. Attachments (list) or Ref3rences:

None II. Reference Code Requiremotet from which relief is desired:

ASME Boiler and Pressure Vessel Code,Section XI, 1986 and 1989 Edition, Article IWA-5250.

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l III. flants for Requenting Rolleft The ASME Boiler and Pressure Vessel Code,Section XI, 1986 and 1989 Edition, Article IWA-5250, CORRECTIVE ME4SUR35, states in  ;

part:

"(a) The source of leakages detected during the conduct of a system pressure test shall be located and evaluated by the owner for corrective measures as follows:

(1) buried components....

(2) if leakage occurs at a bolted connection, the bolting shall be comoved, VT-3 visually examined for corrosion, and evaluated in accordance with IWA-31003 (3) repairs or replacements..."

If a leaking bolted connection is observed during a system pressure test, IWA-5250 (a) (2) requires the removal and inspection of all tha bolting associated with the subject connection. McGuire Nuclear Station Engineering personnel have determined that tha purpose of this requirement is to verify that no unscceptable bolting degradation has occurred (a) ale. : 'ho length s of the bolting or 'b) in the head or nut area wh.c' ,

inter. faces with the mating components of the connection at,.;e the ,

duration of the leakage is unknown.

1 Station personnel have developed in alternative inspection methodology which is equivalent in determining-the condition of the bo'*ad connection while reducing the possibility of personnel injur3 .a burden imposed by IWA-5250 (a) (2) that will be relieved by thin request is as follows:

Current ASME XI requirements involving inspection of bolted connections increase the probability of personnel burn accidents. Susceptibility to the increased risk resuLts from rising containment temperature as a result of the removal of the insulation for inspection of ASME Class 1 bolted connections at high syntem pressure and temperature.

Containment temperatures rine as a result of the removal of the insulation and could affect the integrity of the Ice condenser by sublimation of a portion of the ice. This mandates that the insulation remain in place until just-prior to the VT-2, thus placing plant personnel in a rigorous environment with the relatively high potential for burn accidents.

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tf the proposed Alternative Examination is not available for o' plication and a bolted connection leakage is observed r ating system pressure testing just prior to restart of the Units (Hode 3), an unwarranted delay in unit restart will occur.

IV. Alternate Examinations ,

The proposed alternative methodology will meet t he intent of the IWA-5250 requirement while avoiding or limiting the imposed burdens as stated above. The Alternative Examination will be opplied &c the discretion of station personnel for each Lpecific bolted connection.

(1) All bolted cor.nections within the scope of the planned system pressure testing will be ident. fled.

(2) Tr.e identified connections will be compared to the bolted-connections scheduled for disasocinbly during the outage.

(3) The bolted connections whicn are not schedulod for disassembly during U.e outage will be inspected prior to Mode 5 (cold shutuown) of the outage while the bolted connections are at their normal plant operating pressures.-

The inspection results and / e of inspection for the specific connection will be ocumented in the station work management system.

(4) If a connection is found to be a scurce of leakage, the connection will be disassembled and the bolting inspected

, during the cutage.

(5) System pressure testing associated with the outage will be conducted as normally scheduled. .If a bolted connection is detormined to be a source of leakage, the duration of +.he leakage effect on the bolting will be conservatively determined to be since cne disassembly during the outage.

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(6) With this information, an engineeriaq evaluation can be formally documented to assess the cur.nection. The evaluation will specify the required disassembly date for the bolted connection in order to ensure that unacceptable bolting degradation does not occur. The required disassembly date shall not exceed the nnxt scheduled refueling outage.

The proposed Alternative Examination procedure will provide an acceptable level of quality and safety. Dolting removal and replacemer.t is mandated by the Code because the Owner has no evidence of the condition of bolted connection.

The Alternate Examination procedure permits the performance of either a VT-3 or normal Mechanical Quality control inspection -

documenting the connection disassembly / reassembly thereby identifying all non degraded bolting prior to the system pressure test.

V. Implewnentation Schedule:

The-proposed Alternative E/xminations, if found acceptable, will be implemented during refueting outage End of Cycle (EOC) 9 for both Units 1 and 2.

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