RS-11-002, Response to Request for Additional Information Regarding License Amendment Request for Adoption of Technical Specifications Task Force Traveler TSTF-501, Rev 1, Relocate Stored Fuel Oil & Lube Oil Volume Values to Licensee Control.

Response to Request for Additional Information Regarding License Amendment Request for Adoption of Technical Specifications Task Force Traveler TSTF-501, Rev 1, Relocate Stored Fuel Oil & Lube Oil Volume Values to Licensee Control.

ML110060809
Person / Time
Site:	Clinton
Issue date:	01/06/2011
From:	Simpson P Exelon Generation Co, Exelon Nuclear
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
RS-11-002, TAC ME4850
Download: ML110060809 (6)

Text

Exelon Generation www.exeloncorp.com 4300 Winfield Road Nuclear Warrenville, IL 60555 RS-11-002 10 CFR 50.90 January 6, 2011 U. S. Nuclear Regulatory Commission AnN: Document Control Desk Washington, DC 20555-0001 Clinton Power Station, Unit1 Facility Operating License No. NPF-62 NRC Docket No. 50-461

Subject:

Response to Request for Additional Information Regarding License Amendment Request for Adoption of Technical Specifications Task Force (TSTF) Traveler TSTF-501, Revision 1, "Relocate Stored Fuel Oil and Lube Oil Volume Values to Licensee Control," (TAC No. ME4850)

References:

1. Letter from J. L. Hansen (Exelon Generation Company, LLC) to U. S. NRC, "License Amendment Request for Adoption of Technical Specifications Task Force (TSTF) Traveler TSTF-501, Revision 1, 'Relocate Stored Fuel Oil and Lube Oil Volume Values to Licensee Control, I" dated October 8, 2010

2. Letter from U. S. NRC to Mr. M. J. Pacilio (Exelon Generation Company, LLC), "Clinton Power Station, Unit No.1 - Request for Additional Information Regarding License Amendment Request for Adoption of Technical Specification Task Force-501 ," dated December 7,2010 In Reference 1, Exelon Generation Company, LLC (EGC) requested an amendment to Appendix A, Technical Specifications (TS), of Facility Operating License No. NPF-62 for Clinton Power Station, Unit 1 (CPS). The proposed change modifies the TS by implementing the guidance found in Technical Specifications Task Force (TSTF) Traveler TSTF-501, "Relocate Stored Fuel Oil and Lube Oil Volume Values to Licensee Control," Revision 1.

In Reference 2, the NRC requested that EGC provide additional information in support of their review of Reference 1. The NRC's request for additional information and the specific EGC responses are provided in Attachment 1 to this letter.

January 6, 2011 U. S. Nuclear Regulatory Commission Page 2 The information provided in this letter does not affect the No Significant Hazards Consideration, or the Environmental Consideration provided in Attachment 1 of the original license amendment request as described in the Reference 1 submittal.

In accordance with 10 CFR 50.91 (b), "State consultation," EGC is providing the State of Illinois with a copy of this letter and its attachment to the designated State Official.

This letter contains one regulatory commitment as identified in Attachment 2. If you have any questions concerning this letter, please contact Mr. Mitchel A. Mathews at (630) 657-2819.

I declare under penalty of perjury that the foregoing is true and correct. Executed on the 6th day of January, 2011.

Respectfully,

~~n Manager - Licensing Exelon Generation Company, LLC Attachments:

1. Additional Information Supporting the Application for Technical Specifications Change Regarding Adoption of TSTF-501, Revision 1

2. Summary of Regulatory Commitments

ATTACHMENT 1 Additional Information Supporting the Application for Technical Specifications Change Regarding Adoption of TSTF-501, Revision 1 Request No 1. Please provide the rated nameplate capacity and the maximum post-loss of coolant accident load demand for each emergency diesel generator (EDG).

Request No. 1 Response:

Table 1 below provides the continuous rating, generator nameplate rating, and maximum post loss of coolant accident (LOCA) load demand for each Clinton Power Station, Unit 1 (CPS) emergency diesel generator (EDG).

Table 1: Capacity Ratings by EDG Maximum Post Loss of Continuous Generator Nameplate Diesel Generator Coolant Accident (LOCA)

Rating (kW) Rating (kW)

Load (kW)

Division 1 3869 3900 3894.7 Division 2 3875 3900 3438.1 Division 3 2200 2800 2212 Request No 2. Paragraph 9.5.4.1 of the Clinton Power Station, Unit No. 1 Updated Safety Analysis Report states that the design of the diesel fuel oil system complies with American National Standards Institute (ANSI)

N195-1976, Fuel Oil Systems for Standby Diesels, with exceptions and clarifications to Section 6.3 and Appendix A, Paragraph 1 of Section 7.5, and Paragraph 1d of Section 8. Section 5.4 of ANSI N195-1976 states that:

"The fuel oil storage capacity requirement of 5.2 or 5.3 shall be calculated based upon the diesel-generator(s) operating at the minimum required capacity for the plant condition which is most limiting for the calculation of such capacity. The design shall take into account the time dependence of diesel-generator loads.

It also states that:

"A conservative alternative to calculating the total fuel storage based on time-dependent loads is to calculate the storage capacity by assuming that the diesel operates continuously for seven days at its rated capacity. "

It is further stated that:

A minimum margin of 10 [percent] shall be added to the calculated storage requirement if the conservative alternate calculation is not used.

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ATTACHMENT 1 Additional Information Supporting the Application for Technical Specifications Change Regarding Adoption of TSTF-501, Revision 1 For the Division 1 EDG, the conservative alternate calculation was not used, and the minimum margin of 10% does not appear to have been added to the fuel oil storage capacity requirement calculation in accordance with Section 5.4 of ANSI N195-1976. Also, neither of the two calculation methods in Section 5.4 of ANSI N195-1976 was used. Please explain why the Division 1 EDG fuel oil storage calculation does not meet the requirements of Paragraph 5.4 of ANSI N195-1976.

Request No.2 Response:

The conservative calculation method described in Paragraph 5.4 of ANSI N195-1976 determines the required volume of stored fuel oil using the continuous rating for the EDG. In the case of the Division 1 EDG at CPS, the maximum post-LOCA load demand was applied for the entire 7-day period. As shown in Table 1, the maximum post-LOCA load demand exceeds the continuous rating for the Division 1 EDG. Therefore, since the calculation methodology employed in determining required stored fuel oil for the Division 1 EDG uses a load that is higher than the continuous rating described in Paragraph 5.4 of ANSI N195-1976, the volume of fuel oil determined to be required for the Division 1 EDG is more conservative than the methods described in ANSI N195-1976.

The licensing basis for stored fuel oil at CPS and described in the CPS Safety Evaluation Report (SER) Section 9.6.3.2, IIEmergency Diesel Engine Fuel Oil Storage and Transfer System,1I (Le., Reference 1), the Safety Evaluation (SE) supporting Amendment 13 to the CPS Facility Operating License (Le., Reference 2), and Section 9.5.4 of the CPS Updated Safety Analysis Report (USAR) (Le., Reference 3), is that the stored fuel oil capacity is sufficient to power the diesel engines at maximum post-LOCA load demand (Le., maximum expected emergency loading conditions) for seven days. EGC will revise Section 9.5.4.1 of the CPS USAR to clarify this difference in methodology as discussed in Attachment 2.

Request No 3. Please provide the methodology for the fuel oil storage capacity requirement calculations for the Division 2 and Division 3 EDGs. Please explain why they meet (or why they do not meet) the requirements of Section 5.4 of ANSI N195-1976.

Request No.3 Response:

The calculation methodology that was used in determining the required fuel oil volume for the Division 1 EDG was the same as that used for determining the required amount of fuel oil to meet the volumetric requirements for seven days and six days for Division 2 and Division 3 EDG operation. Specifically, EGC considered fuel oil with the lowest gross heat content per gallon (Le., fuel oil with an API gravity of 38) from the range of API gravities allowed by the CPS Diesel Fuel Oil Testing Program described in CPS Technical Specifications Section 5.5.9. To determine the required amount of stored fuel oil to operate the Division 2 and Division 3 EDGs for seven days and six days, EGC used the maximum post-LOCA load demands and applied Page 2 of 3

AITACHMENT1 Additional Information Supporting the Application for Technical Specifications Change Regarding Adoption of TSTF-501, Revision 1 them for the entire 7-day and 6-day periods to determine fuel oil consumption rates and storage requirements. The basis for this methodology is discussed in References 1, 2, and 3.

Request No 4. Please confirm that the lube oil used is compatible with Ultra Low Sulfur Diesel (ULSD) fuel, and that the lube oil consumption rate does not change when using ULSD.

Request No.4 Response:

The lube oil used at CPS, Mobilgard 450 NC, is specifically formulated for use in marine engines using fuel oil with sulfur contents up to 1.5%, including ULSD. The manufacturer for the CPS EDGs states that the use of diesel fuels with ultra low sulfur content along with high base number engine oils (Le., total base number (TBN) > 13) may result in excessive formation of additive ash deposits. At CPS, the TBN is monitored on a monthly basis. Analysis results between 2006 and 2010 indicate that the TBN for all CPS EDG lubricating oil has remained between 7.63 and 11.67. This range of TBN values is outside the range of concern provided by the CPS EDG manufacturer. The TBNs observed at CPS are low enough to minimize deposits generated due to the use of ULSD. This has been confirmed at CPS through several years of usage with maintenance performed within those periods of usage that do not indicate any excess wear on the cylinders. Moreover, no change in the lube oil consumption rate has been identified with the use of ULSD.

REFERENCES

1. NUREG-0853, "Safety Evaluation Report Related to the Operation of Clinton Power Station, Unit No.1," Section 9.6.3.2, "Emergency Diesel Engine Fuel Oil Storage and Transfer System," dated February 1982

2. Letter from J. Stevens (USNRC) to D. L. Holtzscher (Clinton Power Station), "Technical Specification Change Request to Revise the Number of Gallons of Fuel Oil Specified for the Division II Diesel Generator (1B) (TAC No. 69813)," dated December 19,1988

3. Clinton Power Station Updated Safety Analysis Report (USAR), Section 9.5.4, "Diesel-Generator Fuel Oil Storage and Transfer System" Page 3 of 3

ATTACHMENT 2 Summary of Regulatory Commitments The following table identifies commitments made in this document. Any other actions discussed in the submittal represent intended or planned actions. They are described to the NRC for the NRC's information and are not regulatory commitments.

COMMITTED COMMITMENT TYPE COMMITMENT DATE OR ONE-TIME ACTION Programmatic 1I0UTAGE II (Yes/No) (Yes/No)

Exelon Generation Company, LLC (EGC) will revise the Clinton Power Station, Unit 1 (CPS), Updated Safety Analysis Report, Section 9.5.4.1, to describe an exception to ANSI N195-1976, "Fuel Oil Systems for Standby Diesel Generators,"

Paragraph 5.4, "Calculation of Fuel Oil Storage Requirements," (Le., stored fuel requirements for emergency diesel January 13, 2013 Yes No generators (EDGs) at CPS are determined using maximum post loss of coolant accident load demand for each EDG versus the continuous rating of each EDG).

The revised version of USAR Section 9.5.4.1 will be transmitted to the NRC in the January 10, 2013, USAR update.

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