ML18066A461

Requests Approval to Use Alternative Requirements IAW 10CFR50.55a(a)(3)(i),proposing to Follow Requirements of ASME Boiler & Pressure Vessel Code Case N-566-1.IST Program Relief Request 6 for NRC Approval Encl

ML18066A461
Person / Time
Site:	Palisades
Issue date:	05/14/1999
From:	Haskell N CONSUMERS ENERGY CO. (FORMERLY CONSUMERS POWER CO.)
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
NUDOCS 9905210066
Download: ML18066A461 (6)

Text

A CMS Energy Company Palisades Nuclear Plant Tel: 616 764 2276 27780 Blue Star Memorial Highway Fax: 616 764 2490 Covert, Ml 49043 Nathan L. Hasllsll Director. Licensing May 14, 1999 U.S. Nuclear Regulatory Commission ATTN: Document Control Desk

• Washington, DC 20555 DOCKET 50-255 - LICENSE DPR PALISADES PLANT INSERVICE TESTING PROGRAM -- SUBMITTAL OF PRESSURE TEST RELIEF REQUEST NO. 6 FOR NRC APPROVAL Consumers Energy Company is requesting approval to use alternative requirements in accordance with 10 CFR 50.55a(a)(3)(i). Attached is a request for relief from the requirements of ASME,Section XI, .1989 . EditiOrfr' IWA-5250(a)(2)* as,applied..to *the Palisaees Plant Pressure Testirig.ProgranvThis ireqliest propos*es..to*follow the*,~ ,. ~ .. "::

requirements of the ASME .Boiler ai;id Pressure Vessel:Code.. Case.oN::566-*1 :-appro~ed by the ASME*on.February 15, **1999, as* an*alternative*tothe existing; Code** * * . * *;;. '

1 requirements. If approved, this relief.request (PR-6) would be incorporated into the

• Palisades lnservice Inspection Pressure Test Program for the remainder of the Third Ten-Year Interval, concluding in August 2005. This Relief Request is very similar to the Relief Request submitted by Carolina Power & Light on April 26, 1999, and approved by the NRC on May 4, 1999, for the Brunswick Steam Electric Plant, Docket Nos. 50-325 and 50-324.

Approval of PR-6 is requested on an expedited basis by August 31, 1999, to support planned 1999 refueling outage work on Primary Coolant Pump (PCP) P-50A.Section XI, IWA-5250(a)(2) requires the removal and examination of all bolts when leakage is detected at a bolted connection. When minor leakage was detected at the casing flange of pump P-50A, Relief Request RR-13 was submitted on December 20, 1998, to r;

provide other means of addressing the integrity of the bolting. The NRC provided *J written approval of RR-13 on January 28, 1999 .. Only two of the 16 PCP P-50A casing bolts were known to have any degradation from the known leak at that time. An additional adjacent bolt was recently determined to be slightly corroded, but is well*

within the Se.ction XI Code allowable limits. Given the known condition.of-the P-50A (\ ol.t 1

bolts, a significant reduction:in risk to. the.plant, reduction of dose; and cost savings* - f\

may be realized if the: remaining bo.lts would not require removal. A reduction of 12-16 hours of time at reduced inventory is expected*by reducing* the number of bolts'*.

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2 removed to no more than four. The expected reduced inventory time with all bolts being removed is 164 hours0.0019 days <br />0.0456 hours <br />2.71164e-4 weeks <br />6.2402e-5 months <br />.

A reduction of 740 to 990 mr is expected if only 2 to 4 (of the 16) bolts are removed.

This dose savings and the reduction in reduced inventory time (resulting in a reduction in risk to the plant) justify the request to expedite the NRC review. In addition, this work is currently a critical path for the 1999 refueling outage.

SUMMARY

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

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

ATTACHMENT CONSUMERS ENERGY COMPANY PALISADES PLANT DOCKET 50-255 INSERVICE TESTING PROGRAM -- SUBMITTAL OF PRESSURE TEST RELIEF REQUEST NO. 6 FOR NRC APPROVAL PR-6 3 Pages

PRESSURE TESTING RELIEF REQUEST (PR) NUMBER 6 Code Class: ASME Class 1, 2, and 3

Subject:

Alternative requirements for removal and visual VT-3 examinations of bolting at pressure retaining bolted connections when leakage is detected.

Component Number:

Pressure retaining bolted connections Code Requirements:

ASME Section XI, 1989 Edition, IWA-5250(a)(2) states:

"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;"

Requested Relief:

Relief is requested from the requirements specified in paragraph IWA-5250(a)(2) of the ASME Section XI, 1989 Edition. Consumers Energy Company is requesting approval to use alternative requirements in accordance'with 10 CFR 50.55a(a)(3)(i). If leakage is discovered at a bolted connection, the source of the leakage will be located and evaluated for corrective measures. Where the evaluation of the variables determines the need for further evaluation, the bolt nearest the source of the leakage and any bolts that have been degraded due to the leakage will be removed and a VT-1 examination will be performed on the bolt(s).

Proposed Alternative:

Palisades shall implement the requirements of ASME Boiler and Pressure Vessel Code Case N-566-1, '!Corrective Action for Leakage Identified at Bolted Connections,Section XI, :Division '1,'"when leakage is discovered at a bolted connection during a system pressure test. Code Case N-566-1 requires one of the following actio'ns as an alternative to'the requirements of IWA-5250(a)(2) when leakage is detected at a bolted connection:

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

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PRESSURE TESTING RELIEF REQUEST (PR) NUMBER 6 (b) If the leakage is not stopped, the joint shall be evaluated in accordance with IWB-3142.4 for joint integrity. This evaluation shall include the considerations listed in (c) below.

(c) The evaluation for (a) and (b) above is to determine the susceptibility of the bolting to corrosion and failure. This evaluation shall include the following:

(1) the number and service age of bolts; (2) bolt and component material; (3) corrosiveness of process fluid; (4) leakage location and system function; (5) leakage history at the connection or other system components; (6) visual evidence of corrosion at the assembled connection ..

No immediate action is necessary when the evaluation required by Code Case*

N-566-1 determines that the leaking condition has not degraded the fasteners or the connection, or that the joint integrity will remain acceptable until corrective action for the leak is completed .. However, reasonable attempts shall be made to stop the leakage as appropriate. If the acceptance of the compon~nt is by analytical evaluation, the evaluation analysis shall be submitted to the NRG in accordance with IWB-3144(b).

If the evaluation of the variables above indicates the joint integrity is indeterminate or that there is a need for further evaluation, the following actions shall be taken:.

1. The bolt closest to the source of leakage and any bolts that have been degraded due to the leakage shall be removed;

2. The bolt(s) shall receive a visual VT-1 examination;

3. The visual VT-1 examination results shall be evaluated and dispositioned in accordance with IWB-3517. If the removed bolting shows evidence of rejectable degradation, the bolts adjacent to the removed bolts shall be removed and VT-1 examined and evaluated per IWB-3517..

The bolting removal and the visual VT-1 examination(s) may be deferred to the next outage of sufficient duration if justified.

Basis for Relief:

The ASME Section XI, 1989 Edition (the Code) imposes corrective action including the removal of all bolts at a bol,ted connection, for leakage detected during pressure test, regardless of the circumstances. The removal of all of the bolts may not be necessary to maintain piping,.component and system integrity.

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• v PRESSURE TESTING RELIEF REQUEST (PR) NUMBER 6 However, the Code does not allow the Owner to evaluate the effect of the

• leakage on the bolts in order to determine corrective action or the acceptability of continued service without tt:le removal of all of the bolting.

Leaking conditions at a bolted connection may be an important variable in the degradation of fasteners. However, leakage is not the only variable, and in some cases may not be the degradation mechanism. Other variables to be considered are: bolting materials, leaking medium, duration of the leak, and orientation of the leak (not all bolts may be wetted). These variables are important to consider before disassembling a bolted connection for a visual examination. Removal of bolting at a bolted connection may not be the most prudent decision and may cause undue hardship without a compensating increase in the level of quality or safety. The proposal by Consumers Energy to follow.the requirements 9f ASME Code Case N-566-1 rather than the requirements of IWA-5250(a)(2) will provide an equivalent level of quality and safety at Class 1, 2, and 3 bolted connections.

Applicable Time Period:

Relief is requested for the third ten-year lnservice Inspection Program for Palisc;tdes which concludes in August of 2005. Use of this relief request requires prior NRC approval in accordance with 10 CFR 50.55a(a)(3)(i).

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