RS-13-040, Supplement to the Dresden Nuclear Power Station Fifth Inservice Inspection Interval Relief Request I5R-04

Supplement to the Dresden Nuclear Power Station Fifth Inservice Inspection Interval Relief Request I5R-04

ML13025A161
Person / Time
Site:	Dresden
Issue date:	01/24/2013
From:	Simpson P R Exelon Generation Co
To:	Office of Nuclear Reactor Regulation, Document Control Desk
References
15R-04, RS-13-040
Download: ML13025A161 (6)

Text

RS-13-040 January 24, 2013 10 CFR 50.55a U. S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, D.C. 20555-0001 Dresden Nuclear Power Station, Units 2 and 3 Renewed Facility Operating License Nos. DPR-19 and DPR-25 NRC Docket Nos. 50-237 and 50-249

Subject:

Supplement to the Dresden Nuclear Power Station Fifth Inservice Inspection Interval Relief Request 15R-04

Reference:

Letter from D. M. Gullott (Exelon Generation Company, LLC (EGC)) to U. S. NRC,"Dresden Nuclear Power Station, Units 2 and 3, Fifth Interval Inservice Inspection Program Plan and Relief Requests," dated September 28, 2012 In the referenced letter, EGC submitted relief requests associated with the fifth inservice inspection (ISI) interval for Dresden Nuclear Power Station (DNPS), Units 2 and 3. Following discussions with the NRC, it became apparent that additional clarification is required for the NRC to complete its review of Relief Request 15R-04. Therefore, EGC requests to supersede the version of 15R-04 in the referenced letter with the version in the attachment to this letter in its entirety.

EGC continues to request approval of this relief request by September 28, 2013, to support examination of components during the DNPS, Unit 2 Fall 2013 refueling outage which falls within the fifth 10-year ISI interval.

There are no regulatory commitments contained within this letter.

Should you have any questions concerning this letter, please contact Mr. Mitchel A. Mathews at (630) 657-2819.

Exelon Generation Company, LLC

Attachment:

10 CFR 50.55a Request Number 15R-04, Revision 1 1 RS-13-040 January 24, 2013 U. S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, D.C. 20SSS-0001 Dresden Nuclear Power Station, Units 2 and 3 Renewed Facility Operating License Nos. DPR-19 and DPR-2S NRC Docket Nos. SO-237 and SO-249 10 CFR SO.SSa

Subject:

Supplement to the Dresden Nuclear Power Station Fifth Inservice Inspection Interval Relief Request ISR-04

Reference:

Letter from D. M. Gullott (Exelon Generation Company, LLC (EGC>> to U. S. NRC, "Dresden Nuclear Power Station, Units 2 and 3, Fifth Intervallnservice Inspection Program Plan and Relief Requests," dated September 28, 2012 In the referenced letter, EGC submitted relief requests associated with the fifth inservice inspection (lSI) interval for Dresden Nuclear Power Station (DNPS), Units 2 and 3. Following discussions with the NRC, it became apparent that additional clarification is required for the NRC to complete its review of Relief Request ISR-04. Therefore, EGC requests to supersede the version of ISR-04 in the referenced letter with the version in the attachment to this letter in its entirety.

EGC continues to request approval of this relief request by September 28, 2013, to support examination of components during the DNPS, Unit 2 Fall 2013 refueling outage which falls within the fifth 10-year lSI interval.

There are no regulatory commitments contained within this letter. Should you have any questions concerning this letter, please contact Mr. Mitchel A. Mathews at (630) 6S7 -2819. Sin Patrick R. Simpson Manager -Licensing Exelon Generation Company, LLC

Attachment:

10 CFR SO.SSa Request Number ISR-04, Revision 1 ATTACHMENT 10 CFR 50.55a Request Number 15R-04, Revision 1 Proposed Alternative In Accordance with 10 CFR 50.55a(a)(3)(ii)

--Hardship or Unusual Difficulty without Compensating Increase in Level of Quality and Safety--

ASME Code Component(s) Affected:

Code Class:

Reference:

Examination Category:

Item Number:

==

Description:==

Component Number:

3 IWD-2500, Table IWD-2500-1 D-BB2.10 Testing Frequency for Isolation Condenser Shell Side and Associated Piping Unit No.Drawing Test Block No.

2 M-28, M-39 21CO1, 21C02 3 M-359, M-369 31CO1, 31C02 2.

The Inservice Inspection (ISI) Program is based on the American Society of Mechanical Engineers (ASME) Boiler and Pressure Vessel (B&PV) Code,Section XI, 2007 Edition through the 2008 Addenda.

3.Applicable Code Requirements:

Table IWD-2500-1,"Examination Categories," Examination Category D-B, Item Number D2.10, requires all Class 3 pressure retaining components be subject to a system leakage test with a VT-2 visual examination in accordance with IWD-5220, "System Leakage Test." This system leakage test is to be conducted once each inspection period.

IWD-5221, "Pressure," states that system leakage test shall be conducted at the system pressure obtained while the system, or portion of the system, is in service performing its normal operating function or at the system pressure developed during a test conducted to verify system operability (e.g., to demonstrate system safety function or satisfy technical specification surveillance requirements).

4.

Pursuant to 10 CFR 50.55a(a)(3)(ii), relief is requested on the basis that conformance with the Code requirements impose hardship without a compensating increase in the level of quality and safety.

The Isolation Condenser is not normally in service; it is normally in a standby alignment with its shell side vented to the atmosphere through a non-isolable vent line. For inservice inspection purposes, each unit's Isolation Condenser is divided into two test blocks Page 1 of 5 ATTACHMENT 10 CFR SO.SSa Request Number ISR-04, Revision 1 Proposed Alternative In Accordance with 10 CFR SO.SSa(a)(3)(ii)

--Hardship or Unusual Difficulty without Compensating Increase in Level of Quality and Safety--1. ASME Code Component(s)

Affected:

Code Class:

Reference:

Examination Category:

Item Number: 3 IWD-2500, Table IWD-2500-1 D-B B2.10

Description:

Testing Frequency for Isolation Condenser Shell Side and Associated Piping Component Number: Unit No. Drawing Test Block No. 2 M-28, M-39 21C01, 21C02 3 M-359, M-369 31C01, 31C02 2. Applicable Code Edition and Addenda: The Inservice Inspection (lSI) Program is based on the American Society of Mechanical Engineers (ASME) Boiler and Pressure Vessel (B&PV) Code,Section XI, 2007 Edition through the 2008 Addenda. 3. Applicable Code Requirements:

Table IWD-2500-1, "Examination Categories," Examination Category D-B, Item Number 02.10, requires all Class 3 pressure retaining components be subject to a system leakage test with a VT-2 visual examination in accordance with IWD-5220, "System Leakage Test." This system leakage test is to be conducted once each inspection period. IWD-5221, "Pressure," states that system leakage test shall be conducted at the system pressure obtained while the system, or portion of the system, is in service performing its normal operating function or at the system pressure developed during a test conducted to verify system operability (e.g., to demonstrate system safety function or satisfy technical specification surveillance requirements).

4. Reason for Request: Pursuant to 10 CFR 50.55a(a)(3)(ii), relief is requested on the basis that conformance with the Code requirements impose hardship without a compensating increase in the level of quality and safety. The Isolation Condenser is not normally in service; it is normally in a standby alignment with its shell side vented to the atmosphere through a non-isolable vent line. For inservice inspection purposes, each unit's Isolation Condenser is divided into two test blocks Page 1 of S ATTACHMENT 10 CFR 50.55a Request Number 15R-04, Revision 1 Proposed Alternative In Accordance with 10 CFR 50.55a(a)(3)(ii)

--Hardship or Unusual Difficulty without Compensating Increase in Level of Quality and Safety-(e.g., 21C01 and 21C02 for the Unit 2 Isolation Condenser upper and lower portions, respectively). For example, the DNPS, Unit 2 upper and lower system leakage test blocks are represented in Figures 15R-04.01 and 15R-04.02 below, respectively.

ISOLA7iCN CO WE SE' 2--133 2 Figure 15R

-04.1: Unit 2 Isolation Condenser Test Block No. 21C01 Page 2 of 5 ATTACHMENT 10 CFR SO.SSa Request Number ISR-04, Revision 1 Proposed Alternative In Accordance with 10 CFR SO.SSa(a){3)(ii)

--Hardship or Unusual Difficulty without Compensating Increase in Level of Quality and Safety-(e.g., 21C01 and 21C02 for the Unit 2 Isolation Condenser upper and lower portions, respectively).

For example, the DNPS, Unit 2 upper and lower system leakage test blocks are represented in Figures ISR-04.01 and ISR-04.02 below, respectively.

./". ,/ ./ Figure ISR-04.1:

Unit 2 Isolation Condenser Test Block No. 21C01 Page 2 ofS ATTACHMENT 10 CFR 50.55a Request Number 15R

-04, Revision 1 Proposed Alternative In Accordance with 10 CFR 50.55a(a)(3)(ii)

--Hardship or Unusual Difficulty without Compensating Increase in Level of Quality and Safety--

4SOLA I: N CUND SER 2-?382 Figure 15R

-04.2: Unit 2 Isolation Condenser Test Block No. 21C02 The system is normally aligned with the Isolation Condenser shell side water level greater than or equal to six (6) feet in accordance with Dresden Nuclear Power Station (DNPS), Units 2 and 3 Technical Specifications (TS); however, the shell side water level of the Isolation Condenser is administratively maintained between 7 feet and 7.4 feet in accordance with plant procedures.

Page 3 of 5 ATTACHMENT 10 CFR 50.55a Request Number 15R-04, Revision 1 Proposed Alternative In Accordance with 10 CFR 50.55a{a){3){ii)

--Hardship or Unusual Difficulty without Compensating Increase in Level of Quality and Safety--Figure 15R-04.2:

Unit 2 Isolation Condenser Test Block No. 21C02 The system is normally aligned with the Isolation Condenser shell side water level greater than or equal to six (6) feet in accordance with Dresden Nuclear Power Station (DNPS), Units 2 and 3 Technical Specifications (TS); however, the shell side water level of the Isolation Condenser is administratively maintained between 7 feet and 7.4 feet in accordance with plant procedures.

Page 3 of5 ATTACHMENT 10 CFR 50.55a Request Number 15R-04, Revision 1 Proposed Alternative In Accordance with 10 CFR 50.55a(a)(3)(ii)

--Hardship or Unusual Difficulty without Compensating Increase in Level of Quality and Safety--

Isolation Condenser system operability is verified through performance of TS Surveillance Requirement (SR) 3.5.3.4, "Isolation Condenser System Heat Removal Capability Verification Test," every 60 months (i.e., during two of the three inspection periods for DNPSs fifth ISI interval). The system pressures developed during the performance of this TS surveillance meet the Code requirements of IWD-5221; however, the 60-month frequency does not meet the Table IWD-2500-1 examination frequency requirement of once per inspection period.

Performance of an additional Isolation Condenser heat removal capability test solely for the purposes of performing a system leakage test requires a minimum of a 25% reduction in reactor power to perform the examination. This presents an unnecessary transient on the affected DNPS reactor and a challenge to station operators. Additionally, as previously stated, the isolation condenser shell cannot be isolated and pressurized to meet IWD-5221 examination pressure requirements when in a standby alignment. It would be an abnormal activity to fill the Isolation Condenser to the top simply to achieve a slight increase in static head for the additional system leakage test. As an additional complication, any water added to the isolation condenser shell to raise level above the normal operating level would subsequently have to be drained and processed by radwaste.

In summary, imposing a large transient on the reactor plant to accommodate the performance of the Isolation Condenser heat removal capability verification at a greater frequency than required by DNPS TS and filling the Isolation Condenser to the top to perform a third system leakage test, present hardship without a compensating increase in quality and safety.

5.Proposed Alternative and Basis for Use:

As an alternative, Exelon Generation Company, LLC (EGC) proposes the performance of a system leakage test using a VT-2 visual examination of all DNPS Units 2 and 3 Isolation Condenser Test Blocks (i.e., Test Blocks 2(3)IC01 and 2(3)IC02) every 60 months during the performance of TS SR 3.5.3.4 versus once per inspection period as discussed in Table IWD-2500-1.

As discussed in the previous paragraph, during the DNPS fifth ISI interval EGC proposes that the leakage test of Isolation Condenser Test Blocks 2(3)IC01 (i.e., the upper portion of the Isolation Condenser and associated piping) will only be performed once every 60 months during the performance of TS SR 3.5.3.4 versus once per inspection period as discussed in Table IWD-2500-1.

During inspection periods where TS SR 3.5.3.4 is not performed on a unit's Isolation Condenser, an additional VT-2 examination will be performed for Test Blocks 2(3)IC02 (i.e., the lower portion of the Isolation Condensers and associated piping). This leakage test will be performed with Isolation Condenser shell side water level at the normal standby level versus at the normal pressure when the system is in service performing its normal operating function or at the system pressure developed during a test conducted to verify system operability as discussed in IWD-5221.

Page 4 of 5 ATTACHMENT 10 CFR SO.SSa Request Number ISR-04, Revision 1 Proposed Alternative In Accordance with 10 CFR SO.SSa{a){3){ii)

--Hardship or Unusual Difficulty without Compensating Increase in Level of Quality and Safety--Isolation Condenser system operability is verified through performance of TS Surveillance Requirement (SR) 3.5.3.4, "Isolation Condenser System Heat Removal Capability Verification Test," every 60 months (Le., during two of the three inspection periods for DNPSs fifth lSI interval).

The system pressures developed during the performance of this TS surveillance meet the Code requirements of IWD-5221; however, the 60-month frequency does not meet the Table IWD-2500-1 examination frequency requirement of once per inspection period. Performance of an additional Isolation Condenser heat removal capability test solely for the purposes of performing a system leakage test requires a minimum of a 25% reduction in reactor power to perform the examination.

This presents an unnecessary transient on the affected DNPS reactor and a challenge to station operators.

Additionally, as previously stated, the isolation condenser shell cannot be isolated and pressurized to meet IWD-5221 examination pressure requirements when in a standby alignment.

It would be an abnormal activity to fill the Isolation Condenser to the top simply to achieve a slight increase in static head for the additional system leakage test. As an additional complication, any water added to the isolation condenser shell to raise level above the normal operating level would subsequently have to be drained and processed by radwaste.

In summary, imposing a large transient on the reactor plant to accommodate the performance of the Isolation Condenser heat removal capability verification at a greater frequency than required by DNPS TS and filling the Isolation Condenser to the top to perform a third system leakage test, present hardship without a compensating increase in quality and safety. S. Proposed Alternative and Basis for Use: As an alternative, Exelon Generation Company, LLC (EGC) proposes the performance of a system leakage test using a VT-2 visual examination of all DNPS Units 2 and 3 Isolation Condenser Test Blocks (Le., Test Blocks 2(3)IC01 and 2(3)IC02) every 60 months during the performance of TS SR 3.5.3.4 versus once per inspection period as discussed in Table IWD-2500-1.

As discussed in the previous paragraph, during the DNPS fifth lSI interval EGC proposes that the leakage test of Isolation Condenser Test Blocks 2(3)IC01 (Le., the upper portion of the Isolation Condenser and associated piping) will only be performed once every 60 months during the performance of TS SR 3.5.3.4 versus once per inspection period as discussed in Table IWD-2500-1.

During inspection periods where TS SR 3.5.3.4 is not performed on a unit's Isolation Condenser, an additional VT-2 examination will be performed for Test Blocks 2(3)IC02 (Le., the lower portion of the Isolation Condensers and associated piping). This leakage test will be performed with Isolation Condenser shell side water level at the normal standby level versus at the normal pressure when the system is in service performing its normal operating function or at the system pressure developed during a test conducted to verify system operability as discussed in IWD-5221.

Page 4 ofS ATTACHMENT 10 CFR 50.55a Request Number 15R-04, Revision 1 Proposed Alternative In Accordance with 10 CFR 50.55a(a)(3)(ii)

--Hardship or Unusual Difficulty without Compensating Increase in Level of Quality and Safety--The proposed alternative is based on the hardship imposed by the performance of the heat removal capability verification test at a greater frequency than required by DNPS TS and filling the Isolation Condenser to the top to perform a third system leakage test without a compensating increase in quality and safety.

6.

Relief is requested for the Fifth Ten-Year Inspection Interval for DNPS, Units 2 and 3.

7.

DNPS, Units 2 and 3 fourth inspection interval Relief Request 14R-06 was authorized in an NRC safety evaluation (SE) dated September 4, 2003. The fifth inspection interval relief request (i.e., 15R-04, Revision 1) utilizes a similar approach that was previously approved.Page 5 of 5 ATTACHMENT 10 CFR SO.SSa Request Number ISR-04, Revision 1 Proposed Alternative In Accordance with 10 CFR SO.SSa{a){3){ii)

--Hardship or Unusual Difficulty without Compensating Increase in Level of Quality and Safety--The proposed alternative is based on the hardship imposed by the performance of the heat removal capability verification test at a greater frequency than required by DNPS TS and filling the Isolation Condenser to the top to perform a third system leakage test without a compensating increase in quality and safety. 6. Duration of Proposed Alternative:

Relief is requested for the Fifth Ten-Year Inspection Interval for DNPS, Units 2 and 3. 7. Precedents:

DNPS, Units 2 and 3 fourth inspection interval Relief Request 14R-06 was authorized in an NRC safety evaluation (SE) dated September 4, 2003. The fifth inspection interval relief request (Le., ISR-04, Revision 1) utilizes a similar approach that was previously approved.

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