ML042990534

Response to Request for Additional Information Regarding the Plant License Renewal Application

ML042990534
Person / Time
Site:	Point Beach
Issue date:	10/15/2004
From:	Koehl D Nuclear Management Co
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
NRC 2004-01 01, TAC MC2099, TAC MC2100
Download: ML042990534 (5)

Text

Committed to Nuclear Excellenc Point Beach Nuclear Plant Operated by Nuclear Management Company, LLC October 15, 2004 NRC 2004-01 01 10 CFR 54 U.S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, DC 20555 Point Beach Nuclear Plant, Units 1 and 2 Dockets 50-266 and 50-301 License Nos. DPR-24 and DPR-27 Response to Request for Additional Information Regarding the Point Beach Nuclear Plant License Renewal Application (TAC Nos. MC2099 and MC2100)

By letter dated February 25, 2004, Nuclear Management Company, LLC (NMC),

submitted the Point Beach Nuclear Plant (PBNP) Units 1 and 2 License Renewal Application (LRA). On September 16, 2004, the Nuclear Regulatory Commission (NRC) requested additional information regarding Aging Management Program XL.M33, "Selective Leaching of Material." The enclosure to this letter contains the NMC's response to the staffs questions.

Should you have any questions concerning this submittal, please contact Mr. James E. Knorr at (920) 755-6863.

Summary of Commitments This letter makes the following new commitment:

As part of LRA Section B.2.1.13, "One Time Inspection Program," a one-time visual inspection and hardness measurement will be performed on accessible locations of a select set of components of each material type (i.e., cast iron and brass) to determine whether selective leaching has occurred and whether the resulting loss of strength and/or material will affect the intended functions of these components during the period of extended operation.

0cf 6590 Nuclear Road

• Two Rivers, Wisconsin 54241 Telephone: 920.755.2321

Document Control Desk Page 2 I declare under penalty of perjury that the forgoing is true and correct. Executed on October 15, 2004.

Dennis L. Koehi Site Vice-President, Point Beach Nuclear Plant Nuclear Management Company, LLC Enclosure cc:

Administrator, Region Ill, USNRC Project Manager, Point Beach Nuclear Plant, USNRC Resident Inspector, Point Beach Nuclear Plant, USNRC PSCW

ENCLOSURE RESPONSE TO REQUEST FOR-ADDITIONAL INFORMATION POINT BEACH NUCLEAR PLANT, UNITS I AND 2 LICENSE RENEWAL APPLICATION NRC Question RAI B.2.1.13-1:

NUREG-1801 (GALL Report) Aging Management Program (AMP) XL.M33, "Selective Leaching of Material," program Element 4, uDetection of Aging Effects" established the following criteria:

The one-time visual inspection and hardness measurement includes close examination of a select set of components to determine whether selective leaching has occurred and whether the resulting loss of strength and/or material will affect the intended functions of these components during the period of extended operation. Selective leaching generally does not cause changes in dimensions and is difficult to detect. However, in certain brasses it causes plug-type dezincification, which can be detected by visual inspection. One acceptable procedure is to visually inspect the susceptible components closely and conduct Brinell Hardness testing on the inside surfaces of the selected set of components to determine if selective leaching has occurred. If it is occurring, an engineering evaluation is initiated to determine acceptability of the affected components for further service.

The Point Beach LRA Section B.2.1.13, "One-Time Inspection Program," is used to manage the selective leaching aging mechanism and is cited as being consistent with GALL Report AMP XI.M33, with exceptions. The LRA identifies the following exception to GALL Report AMP XI.M33:

This element includes exceptions to the corresponding NUREG-1801, Section XL.M33, 'Selective Leaching of Materials" aging management program element. Section XL.M33 of NUREG-1801 states that hardness measurements are performed on a select set of components. The internal surfaces of susceptible components may not be accessible for hardness measurements due to the size of the component. Therefore, only visual inspections are required by the program. Hardness measurements may be performed in accessible locations to confirm the absence of selective leaching and determine material properties which can be used in component functionality assessments.

The NRC project team conducted discussions concerning this exception with PBNP personnel during its site visits. The project team has further evaluated this exception Page 1 of 3

and is unable to reconcile how leaching of cast iron and brass would be effectively managed using only visual inspection; that is without performance of hardness testing on the inside surfaces of the selected set of components. The inability to reconcile this exception is predicated on XI.M33, which indicates that visual inspections are generally unable to detect leaching. However, the project team acknowledges that components with limited accessibility may be one factor in choosing the "selected set of components" upon which the hardness tests are to be performed. The PBNP exception indicates that "hardness measurements may be performed," which therefore makes hardness testing optional. This is an important consideration in the project team's evaluation of this exception.

PBNP is requested to provide additional information that demonstrates that visual inspection alone will guarantee detection of leaching in cast iron and brass materials.

Otherwise please indicate whether or not the Nuclear Management Company will perform a one-time visual inspection and hardness measurement on select set of components, of each material type, to determine whether selective leaching has occurred and whether the resulting loss of strength and/or material will affect the intended functions of these components during the period of extended operation.

NMC Response:

PBNP LRA Section B.2.1.13, "One-Time Inspection ProQram," program Element 4, "Detection of AQing Effects" A one-time visual inspection and hardness measurement will be performed on accessible locations of a select set of components of each material type (i.e., cast iron and brass) to determine whether selective leaching has occurred and whether the resulting loss of strength and/or material will affect the intended functions of these components during the period of extended operation. The internal surfaces of susceptible components may not be accessible for hardness measurements due to the size of the component. Therefore, one of the factors used in choosing the selected set of components to be inspected for selective leaching will be the accessibility of the internal surface of the component for hardness testing. Hardness measurements will be performed in accessible locations to confirm the absence of selective leaching and determine material properties which can be used in component functionality assessments.

During the aging management review process it was not always possible to determine whether the cast iron components in question were constructed of gray or ductile cast iron. In many cases the material specification only stated cast iron. In these cases, PBNP conservatively assumed that the material was gray cast iron and susceptible to selective leaching. Should further material evaluation determine that the material is ductile cast iron and therefore not susceptible to selective leaching, these components would be removed from the selected set of components to be inspected for selective leaching.

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This program Element 4, uDetection of Aging Effects" is consistent with the corresponding NUREG-1801,Section XI.M33, "Selective Leaching of Materials," aging management program element.

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