ML100770431

Third Ten-Year Inservice Test Program Interval, Pump Specific Relief Request No. ON-SRP-HPI-03

ML100770431
Person / Time
Site:	Oconee
Issue date:	03/11/2010
From:	Baxter D Duke Energy Carolinas
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
ON-SRP-HPI-03
Download: ML100770431 (6)

Text

'Duke DAVE BAXTER Vice President 0Energy. Oconee Nuclear Station Duke Energy ON01 VP / 7800 Rochester Highway Seneca, SC 29672 864-873-4460 864-873-4208 fax dabaxter@dukeenergy.com March 11, 2010 U.S. Nuclear Regulatory Commission Document Control Desk Washington, DC 20555

Subject:

Duke Energy Carolinas, LLC Oconee Nuclear Station, Units 1, 2, 3 Docket Nos. 50-269. 270, 287 Third Ten-Year Inservice Test Program Interval Pump Specific Relief Request No. ON-SRP-HPI-03 Pursuant to 10 CFR 50.55a(f)(5)(iii) and 10 CFR 50.4, Oconee Nuclear Station (ONS)hereby requests Nuclear Regulatory Commission (NRC) approval of the following code relief for the third ten-year interval inservice test program.Relief is requested from certain requirements for vibration monitoring specified by the American Society of Mechanical Engineers (ASME) Operational and Maintenance Code, 1995 Edition, 1996 Addenda. This request is to allow Duke Energy Carolinas, LLC (Duke Energy) to take exception to vibration monitoring requirements for the upper motor bearing housing on the High Pressure Injection pumps for all three ONS units on the basis of impracticality.

Details of the determination of impracticality are provided in the enclosed 10CFR50.55a request.Duke Energy requests approval by September 30, 2010. There are no commitments associated with this request.If there are any questions or further information is needed, you may contact R. L. Oakley at (864) 873-3829.Sincerely, Dave Baxter, Vice President Oconee Nuclear Site Enclosure www. duke-energy.

com U. S. Nuclear Regulatory Commission March 11, 2010 Page 2 xc w/encl: Mr. Luis Reyes Administrator, Region II U.S. Nuclear Regulatory Commission Sam Nunn Atlanta Federal Center 61 Forsyth St., SWW, Suite 23T85 Atlanta, GA 30303-8931 Mr. John Stang Project Manager U. S. Nuclear Regulatory Commission Office of Nuclear Reactor Regulation Mail Stop 0-8 G9A Washington, DC 20555 Mr. Andy Sabisch Senior NRC Resident Inspector Oconee Nuclear Station Mr. Henry Porter Division of Radioactive Waste Management Bureau of Land and Waste Management SC Dept. of Health & Environmental Control 2600 Bull St.Columbia, SC 29201 U. S. Nuclear Regulatory Commission March 11, 2010 ENCLOSURE I Relief Request ON-SRP-HPI-03 (Inservice Testing Impracticality)

Oconee Units 1, 2, 3 Pump Specific Relief Request 10 CFR 50.55a Request Number: ON-SRP-HPI-03 Relief Requested In Accordance with 10 CFR 50.55a(f)(5)(iii)

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Inservice Testing Impracticality

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1. ASME Code Component(s)

Affected 1HPIPU0001, 1HPIPU0002, 1HPIPU0003 2HPIPU0001, 2HPIPU0002, 2HPIPU0003 3HPIPU0001, 3HPIPU0002, 3HPIPU0003

2. Applicable Code Edition and Addenda ASME Operational and Maintenance Code 1995 Edition, 1996 Addenda 3. Applicable Code Requirement Per OMa-1996 Subsection ISTB 4.7.4 b, vibration measurements shall be taken on the upper motor bearing housing in three approximately orthogonal directions, one of which is the axial direction for vertical line shaft pumps.4. Impracticality of Compliance The OM Code required vibration measurements on the upper motor bearing housing for the subject pumps are impractical on the basis of inaccessibility due to location and design features of the motor. Plant design did not include permanent scaffolding or ladders which provide access to the top of the motors for the subject pumps. Also, the upper motor bearing housing is contained within a cone shaped fiberglass protective shroud which obstructs access to the bearing housing and prevents performance of the axial vibration measurement.

In order to perform the required measurements, the component would need to be redesigned to eliminate the shroud or the shroud would have to be removed for each test. Both of these options are impractical.

In addition, removal of the shroud during pump operation to provide direct access to the bearing housing would create an additional equipment concern due to the potential for foreign material intrusion and component damage. Vibration measurements taken on the fiberglass shroud would not provide useful or meaningful information. (See attached drawing OM-0314-0063 for details.)5. Burden Caused by Compliance To facilitate compliance with the Code testing requirement, the plant would need to be modified to provide a permanent ladder and platform for access to 2/9/10 ON-SRP-HPI-03 Rev. 26c Page 1 of 2 Oconee'Units 1, 2, 3 the bearing on each of nine motors. Also each pump/motor assembly would have to be redesigned to remove the bearing shroud during pump operation.

Since this would subject the component to potential damage by foreign material intrusion, the pump/motor redesign would have to provide protection from foreign material intrusion while still allowing access. These modifications are impractical and create unnecessary burden.6. Proposed Alternative and Basis for Use The HPI pumps are considered Group A, vertical line shaft pumps. Quarterly vibration readings are taken at two locations on the motor and two locations on the pump. Locations on the motor are at the inboard bearing and approximately midway on the motor housing. Locations on the pump are the pump inboard bearing and on the pump stand. At each location, vibration measurements are recorded in two approximately orthogonal directions perpendicular to the rotating shaft. These locations have been chosen for monitoring in an effort to identify specific failure modes and have proven to provide early indication of abnormal pump / motor performance.

Monitoring of the pump / motor vibrations at these locations will ensure the health of the pump is sufficiently examined.

It is worth noting that the OM Code imposes more stringent hydraulic acceptance criteria on these pumps than for horizontal centrifugal or positive displacement pumps. This more stringent hydraulic acceptance criteria places more emphasis on detection of degradation through hydraulic test data than through mechanical test data.Application of the OM hydraulic testing criteria along with radial vibration monitoring in the areas described above will provide adequate data for assessing the condition of the subject pumps and for monitoring degradation.

Therefore, reasonable assurance of operational readiness for these pumps will be' maintained.

7. Duration of Proposed Alternative This proposed test alternative will be imposed for the duration of the current 120 month interval (fourth interval, which began July 1, 2002).8. Precedents Specific relief has been granted from the code vibration requirements where the upper motor bearing housing is inaccessible (Hatch Safety Evaluation dated June 13, 1994, Docket numbers 50-321 and 50-366, TAC numbers M59202, M59203, M83192, M83193).2/9/10 ON-SRP-HPI-03 Rev. 26c Page 2 of 2