ML103540505
| ML103540505 | |
| Person / Time | |
|---|---|
| Site: | Peach Bottom  |
| Issue date: | 12/30/2010 |
| From: | John Hughey Plant Licensing Branch 1 |
| To: | Pacilio M Exelon Generation Co |
| Hughey J, NRR/DORL, 301-415-3204 | |
| References | |
| TAC ME4131, TAC ME4132 | |
| Download: ML103540505 (4) | |
Text
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December 30, 2010
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Mr. Michael J. Pacilio President and Chief Nuclear Officer Exelon Generation Company, LLC 4300 Winfield Road Warrenville, IL 60555
SUBJECT:
PEACH BOTTOM ATOMIC POWER STATION, UNITS 2 AND 3 - REQUEST FOR ADDITIONAL INFORMATION REGARDING LICENSE AMENDMENT REQUEST RELATED TO LIQUID NITROGEN STORAGE (TAC NOS. ME4131 AND ME4132)
Dear Mr. Pacilio:
By letter to the Nuclear Regulatory Commission (NRC) dated June 25, 2010 (Agencywide Documents Access and Management System (ADAMS) Accession No. ML101790114), Exelon Generation Company, LLC, (Exelon) submitted a request to revise the Technical Specifications (TS) for the Peach Bottom Atomic Power Station, Units 2 and 3. The proposed change would revise TS Surveillance Requirement (SR) 3.6.1.3, "Primary Containment Isolation Valves," and SR 3.6.1.5, "Reactor Building-to-Suppression Chamber Vacuum Breakers," to modify the required level for the liquid nitrogen storage tank. Exelon supplemented the amendment request on August 16, 2010, and on December 6, 2010 (ADAMS Accession Nos. ML102310079 and ML103410398). The NRC staff has reviewed the request and supplements submitted by the licensee and determined that additional information is needed as set forth in the Enclosure.
The draft questions were sent to Mr. Richard Gropp, of your staff, to ensure that the questions were understandable, the regulatory basis for the questions were clear, and to determine if the information was previously docketed. On December 27,2010, Mr. Gropp indicated that the licensee will submit a response by January 26, 2011. Please note that if you do not respond to this letter by the agreed-upon date or provide an acceptable alternate date in writing, we may reject your application for amendment under the provisions of Title 10 of the Code of Federal Regulations, Section 2.108.
If you have any questions, please contact me at (301) 415-3204.
s:nc;rel YahJc0.
~gheY. Project Manager Plant Licensing Branch 1-2 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket Nos. 50-277 and 50-278
Enclosure:
As stated cc w/encl: Distribution via ListServ
REQUEST FOR ADDITIONAL INFORMATION REGARDING LICENSE AMENDMENT REQUEST RELATED TO LIQUID NITROGEN STORAGE PEACH BOTTOM ATOMIC POWER STATION, UNITS 2 AND 3 DOCKET NOS. 50-277 AND 50-278 By letter to the Nuclear Regulatory Commission (NRC) dated June 25,2010 (Agencywide Documents Access and Management System (ADAMS) Accession No. ML101790114), Exelon Generation Company, LLC, (Exelon) submitted a request to revise the Technical Specifications (TS) for the Peach Bottom Atomic Power Station, (PBAPS) Units 2 and 3. The proposed change would revise TS Surveillance Requirement (SR) 3.6.1.3.1, "Primary Containment Isolation Valves (PCIVs)," and SR 3.6.1.5.1, "Reactor BUilding-to-Suppression Chamber Vacuum Breakers," to modify the required level for the liquid nitrogen storage tank. Exelon supplemented the amendment request on August 16, 2010, and on December 6, 2010 (ADAMS Accession Nos. ML102310079 and ML103410398). The NRC sfaff has reviewed Exelon's submittal and supplements and determined that additional information, as described below, is needed to complete the review.
Originally, the NRC staff requested supplemental information by letter dated July 30, 2010 (ADAMS Accession No. ML102110061). The NRC staff limited its request to only the calculations associated with the liquid nitrogen tank level/volume correlation. However, in its August 16, 2010, response, Exelon provided the entire design analysis calculation PM-0375, Revision 4, To Establish Demand for N2 for the CAD [containment atmospheric dilution] System and the SGIG [safety grade instrument gas] System for Dual Unit Operation." While the information in the submitted design analysis calculation exceeds the scope of the supplemental information requested by the NRC, the entire calculation does relate to the amendment request under review. The NRC staff has reviewed Exelon's submittal and supplements and determined that additional information, as described below, is needed to complete the review.
Exelon Calculation PM-0375, Revision 4, provides the basis used to establish TS surveillance 3.6.1.3.1 and 3.6.1.5.1 pursuant to Title 10 of the Code of Federal Regulations (10 CFR) 50.36.
10 CFR 50.36(c)(2) states, in part, that a TS limiting condition for operation must be established for any structure, system, or component for operation at the lowest functional capability or performance levels of equipment required for safe operation of the facility. 10 CFR 50.36(c)(3) states that surveillance requirements are requirements relating to test, calibration, or inspection to assure that the necessary quality of systems and components is maintained, that facility operation will be within safety limits, and that the limiting conditions for operation will be met.
10 CFR 50 App B states, in part, that the design control measures shall provide for verifying or checking the adequacy of design, such as by the performance of design reviews, by the use of alternate or simplified calculational methods, or by the performance of a suitable testing program.
Exelon Calculation PM-0375, Revision 4, determined that the minimum amount of nitrogen needed for the SGIG system for a 7-day period following a loss-of-coolant accident (LOCA) is 120,000 standard cubic feet (scf). The calculation also determined that 80,422 scf of this total is required to account for system leakage for the 7-day period. The calculation bases the system Enclosure
- 2 leakage on data collected during a year-long test on the SGIG system. However, the licensee tested only a limited portion of the SGIG system. The SGIG system was not in a configuration that represents the system lineup during an accident condition when the SGIG system is providing nitrogen from the CAD tank to safety-related components. Therefore, it appears that Calculation PM-0375 does not accurately represent the entire SGIG system leakage while in the post-LOCA configuration.
The previous revision of Calculation PM-0375 included a margin of only 9,981 scf of nitrogen to account for system leakage. Revision 4 of Calculation PM-0375 increased the margin to 80,422 scf to account for the nitrogen leakage based on the limited testing scope described above. The update to Calculation PM-0375 shows a significant increase in margin required to account for only a limited portion of system leakage. The portion of the SGIG system not accounted for in the system leakage calculation may require an additional amount of nitrogen above the margin allowed in the calculation.
RAI-02
Provide a suitable method and justification for determining the required amount of nitrogen in the storage tank that would account for leakage of the entire SGIG system while in post-LOCA line-up.
RAI-03
Since the system leakage represents such a significant amount of the required quantity of nitrogen, the NRC staff requests that the licensee either justify how the existing surveillance requirement (Le. tank level of 22 inches) will assure that future leakage rates will not increase to a point where 22 inches will no longer sustain the SGIG system for the 7-day period, or propose new surveillance requirements that meet the requirements of 50.36(c)(3).
December 30,2010 Mr. Michael J. Pacilio President and Chief Nuclear Officer Exelon Generation Company, LLC 4300 Winfield Road Warrenville, IL 60555 SUB~IECT:
PEACH BOTTOM ATOMIC POWER STATION, UNITS 2 AND 3 - REQUEST FOR ADDITIONAL INFORMATION REGARDING LICENSE AMENDMENT REQUEST RELATED TO LIQUID NITROGEN STORAGE (TAC NOS. ME4131 AND ME4132)
Dear Mr. Pacilio:
By letter to the Nuclear Regulatory Commission (NRC) dated June 25, 2010 (Agencywide Documents Access and Management System (ADAMS) Accession No. ML101790114), Exelon Generation Company, LLC, (Exelon) submitted a request to revise the Technical Specifications (TS) for the Peach Bottom Atomic Power Station, Units 2 and 3. The proposed change would revise TS Surveillance Requirement (SR) 3.6.1.3, "Primary Containment Isolation Valves," and SR 3.6.1.5, "Reactor Building-to-Suppression Chamber Vacuum Breakers," to modify the required level for the liquid nitrogen storage tank. Exelon supplemented the amendment request on August 16, 2010, and on December 6,2010 (ADAMS Accession Nos. ML102310079 and ML103410398). The NRC staff has reviewed the request and supplements submitted by the licensee and determined that additional information is needed as set forth in the Enclosure.
The draft questions were sent to Mr. Richard Gropp, of your staff, to ensure that the questions were understandable, the regulatory basis for the questions were clear, and to determine if the information was previously docketed. On December 27,2010, Mr. Gropp indicated that the licensee will submit a response by January 26,2011. Please note that if you do not respond to this letter by the agreed-upon date or provide an acceptable alternate date in writing, we may reject your application for amendment under the provisions of Title 10 of the Code of Federal Regulations, Section 2.108.
If you have any questions, please contact me at (301) 415-3204.
Sincerely,
/raj John D. Hughey, Project Manager Plant Licensing Branch 1-2 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket Nos. 50-277 and 50-278
Enclosure:
As stated cc w/encl: Distribution via ListServ DISTRIBUTION:
PUBLIC LPLI-2 R/F RidsNrrDorlDpr Resource RidsNrrLAABaxterResource RidsOgcRpResource RidsNrrDssSbpb RidsRgn1MailCenterResource RidsNrrDorlLpl1-2Resource RidsNrrDirsltsb RidsNrrPMPeachBottomResource RidsAcrsAcnw_MailCTRResource ADAMS Accession No.: ML103540505
- via email OFFICE LPL1-2/PM LPL1-2/LA SBPB/BC LPL1-2/BC NAME JHughey ABaxter
- GCasto HChernoff (GMiller for)
DATE 12/30/2010 12/27/2010 12/10/2010 12/30/2010 OFFICIAL RECORD COpy