AEP-NRC-2009-53, Third Ten-Year Interval Inservice Inspection Program Relief Request ISIR-32
| ML092680143 | |
| Person / Time | |
|---|---|
| Site: | Cook  |
| Issue date: | 09/15/2009 |
| From: | Hruby R Indiana Michigan Power Co |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| AEP-NRC-2009-53 | |
| Download: ML092680143 (6) | |
Text
Indiana Michigan Power Company Nuclear Generation Group INDIANA One Cook Place MICHIGAN Bridgman, MI 49106 POWER aep.com September 15, 2009 AEP-NRC-2009-53 10 CFR 50.55a U. S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, D.C. 20555-00011.
SUBJECT:
Donald C. Cook Nuclear Plant Unit 1 Docket No..50-315 Third Ten-Year Interval Inservice Inspection Program Relief Request ISIR-32
Dear Sir or Madam:
Pursuant to 10 CFR 50.55a(a)(3)(ii), Indiana Michigan Power Company (I&M), the licensee for Donald C. Cook Nuclear Plant Unit 1, hereby requests Nuclear Regulatory Commission approval of the following request for the Unit 1 third ten-year interval inservice inspection program:
Relief Request ISIR-32 proposes an alternative to the volumetric examination of the Steam Generator Inlet and Outlet Primary Manway Studs. Compliance with the specified requirements would result in hardship or unusual difficulty without a compensating increase in the level of quality and safety. The details of the 10 CFR 50.55a requests are enclosed.
I&M requests approval by February 3, 2010, to allow use of the alternative during the Unit 1 Cycle 23 refueling outage.
There is one new commitment in this letter. Should You have any questions, please contact Mr. James M. Petro, Jr., Regulatory Affairs Manager, at (269) 466-2489.
Sincerely, Raymond A. Hruby, Jr.-
Vice President - Site Support Services RSP/rdw
Enclosures:
- 1. Relief Request ISIR-32
- 2. Regulatory Commitment c: T. A. Beltz - NRC Washington, DC J. T. King - MPSC S. M. Krawec, Ft. Wayne AEP MDEQ - WHMD/RPS NRC Resident Inspector M. A. Satorius - NRC Region III
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Noz-
Enclosure 1 to AEP-NRC-2009-53 10 CFR 50.55a Relief Request Number ISIR-32 Proposed Alternative In accordance with 10 CFR 50.55a(a)(3)(ii)
--Hardship or Unusual Difficulty Without a Compensating Increase in Level of Quality or Safety--
- 1. American Society of Mechanical Engineers (ASME) Code Component Affected Code Class: Class 1 Table: IWB-2500-1 Category: B-G-1 Item Number: B6.90 System: Reactor Coolant Pressure Boundary Code Component Affected: STM-11-IMB-1 thru 16, STM-11-OMB-1 thru 16 STM-12-IMB-1 thru 16, STM-12-OMB-1 thru 16 STM-13-1MB-1 thru 16, STM-13-OMB-1 thru 16 STM-14-IMB-1 thru 16, STM-14-OMB-1 thru 16
Description:
Steam Generator (SG) Inlet and Outlet Primary Manway Studs
2. Applicable Code Edition and Addenda
The Code of Record for the Third Ten-Year inservice inspection (ISI) interval at Donald C. Cook Nuclear Plant (CNP) Unit 1 is the ASME Boiler and Pressure Vessel Code,Section XI, 1989 Edition, with no Addenda.
The CNP Unit 1 Third Ten-Year ISI interval began July 1, 1996, and will conclude on February 28, 2010.
3. Applicable Code Requirement
ASME Code Section XI, Table IWB-2500-1, Category B-G-1, Item B6.90, requires a volumetric exam of the SG Inlet and Outlet Primary Manway Studs in accordance with Figure IWB-2500-12.
4. Reason for Request
4.1 Background Information Indiana and Michigan Power Company (I&M) replaced CNP Unit 1 SGs in 2000. In September 2008, CNP Unit 1 experienced a failure of the low pressure turbines. This failure resulted in the unit being shutdown for an extended maintenance outage.
Consequently, the scheduled Fall 2009 refueling outage (U1C23), which is the last refueling outage of the Third Ten-Year ISI Interval, was moved to March 2010. The Fall 2011 refueling outage (U1C24) is scheduled for October 2011, of the Fourth Ten-Year ISI Interval.
to AEP-NRC-2009-53 Page 2 The Unit 1 SG inspection activities (i.e., primary side manway cover and stud removal, Eddy Current Testing, secondary side inspections, and cleaning) are now scheduled for U1C24. This shift in the inspection schedule is permitted by Technical Specifications 5.5.7.d. As a result, SG inspection activities will not be performed during U1C23 as previously forecasted.
The SG Inlet and Outlet Primary Manway Studs were also scheduled to be examined during U1C23 when the primary and secondary manways were removed for the SG Eddy Current Testing. This allows CNP to maintain personnel dose levels as low as reasonably achievable (ALARA).
With the SG Eddy Current Testing scheduled for U1C24 and inspections of the SG primary manway studs scheduled during U1C23, the SG manways will now be required to be removed in consecutive outages. Removal of the SG manways in consecutive outages will result in additional personnel radiation dose. It is desirable to re-align the inspection of the SG primary manway studs with the SG Eddy Current Testing to maintain personnel radiation dose ALARA. Approval of this relief request would allow for SG Eddy Current Testing and volumetric inspection of the SG Inlet and Outlet Primary Manway Studs to be performed during U1C24.
4.2 Hardship or Unusual Difficulty I&M considered performing a volumetric exam of the SG Inlet and Outlet Primary Manway Studs during the U1C23 refueling outage; however, the dose estimate projected for these examinations would result in hardship without a compensating increase in the level of quality and safety.
The ISI volumetric examinations of the SG Inlet and Outlet Primary Manway Studs will require equipment setup/teardown, manway and diaphragm removal and reinstallation, stud and stud hole cleaning and inspection. Additionally, these manways have historically been impeded by stuck studs which increase the dose for the job scope.
The dose estimate to perform inspection of the SG Inlet and Outlet Primary Manway Studs is based on a radiological survey obtained from performance of a similar evolution of the Eddy Current Testing of the SGs during a prior Unit 1 refueling outage (U1C21);
therefore, the dose estimate is believed to be reasonably accurate. The dose estimated for.this scope of work is 5.1 rem assuming no stuck studs. The estimated additional dose for removal of a stuck stud is 1.0 rem per stuck stud.
I&M believes that inspection of the SG Inlet and Outlet Primary Manway Studs during U1C23 would result in hardship without a compensating increase in the level of quality and safety due to ALARA consid'erations. Based on ALARA considerations, I&M is proposing to reschedule the inspection of the SG Inlet and Outlet Primary Manway Studs to coincide with the SG Inlet and Outlet Primary Manway Stud removal for Eddy Current Testing during U1C24 through the application of this relief request.
to AEP-NRC-2009-53 Page 3
- 5. Proposed Alternative and Basis for Use 5.1 ProposedAlternative In accordance with 10 CFR 50.55a(a)(3)(ii), an alternative is proposed on the basis that compliance with the ASME code requirement would result in hardship or unusual difficulty without a compensating increase in the level of quality and safety. As an alternative to the applicable ASME code examination requirements, a visual examination (VT-2) of the SG manway area with the insulation installed will be performed during the U1C23 refueling outage at nominal operating temperature and pressure. This examination is conducted in accordance with ASME Code Section Xl, Table IWB-2500-1 Examination Category B-P, Item B15.50.
The VT-2 examination is augmented by the leakage detection methods noted below.
5.2 Basis for Use The proposed alternative will provide indication of a degraded condition that could prevent the SG Inlet and Outlet Primary Manway Studs from performing their function.
The Unit 1 SGs were replaced in 2000. In September 2008, CNP Unit 1 experienced a failure of the low pressure turbines that resulted in an extended shutdown. Therefore, the CNP Unit 1 SGs effective full power years of 8.4 years (projected to Fall 2011) will not exceed an inservice life of ten years if inspection of the SG Inlet and Outlet Primary Manway Studs are performed in U1C24. I&M will perform volumetric examination of the Unit 1 SG Inlet and Outlet Primary Manway Studs during U1C24. This provides reasonable assurance of structural integrity of the SG Inlet and Outlet Primary Manway Studs.
There are several additional methods available to detect a manway leak during plant operation. Listed below are some examples:
- a. Control room operators perform Operation Surveillance Test, "Reactor Coolant System Leak Rate Test," daily with the plant operating at steady state conditions.
Leakage would be discovered by the conduct of this test.
- b. Containment airborne radiation monitors continuously sample the containment atmosphere and alarm in the control room. This detection method is dependent on the size of the leak, reactor coolant activity, and containment background activity.
- c. Leakage would cause an increase in containment pressure, temperature and humidity, which are indicated in the control room. Additionally, high containment pressure produces an alarm in the control room.
- d. Substantial leakage would collect in the containment sump. The sump level is indicated and alarmed in the control room.
to AEP-NRC-2009-53 Page 4
- 6. Duration of Proposed Alternative The proposed alternative is requested for use during the Third Ten-Year ISI interval for CNP Unit 1.
Enclosure 2 to AEP-NRC-2009-53 Regulatory Commitment The following table identifies those actions committed to by Indiana Michigan Power Company (I&M) in this document. Any other actions discussed in this submittal represent intended or planned actions by I&M. They are described to the Nuclear Regulatory Commission (NRC) for the NRC's information and are not regulatory commitments.
Commitment Date I&M will perform volumetric examination of the Unit 1 Steam U1C24 currently scheduled Generator Inlet and Outlet Primary Manway Studs during for Fall 2011 U1 C24.