ML101870024
| ML101870024 | |
| Person / Time | |
|---|---|
| Site: | Limerick  |
| Issue date: | 07/15/2010 |
| From: | Peter Bamford Plant Licensing Branch 1 |
| To: | Chernoff H Plant Licensing Branch 1 |
| Bamford, Peter J., NRR/DORL 415-2833 | |
| References | |
| TAC ME3589, TAC ME3590 | |
| Download: ML101870024 (5) | |
Text
July 15, 2010 MEMORANDUM TO: Harold K. Chernoff, Chief Plant Licensing Branch I-2 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation FROM:
Peter Bamford, Project Manager /ra/
Plant Licensing Branch I-2 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation
SUBJECT:
LIMERICK GENERATING STATION, UNITS 1 AND 2 - ELECTRONIC TRANSMISSION, DRAFT REQUEST FOR ADDITIONAL INFORMATION REGARDING MEASUREMENT UNCERTAINTY RECAPTURE POWER UPRATE (TAC NOS. ME3589 AND ME3590)
The attached draft request for additional information (RAI) was transmitted by electronic transmission on July 8, 2010, to Mr. Kevin Borton, at Exelon Generation Company, LLC (Exelon). This draft RAI was transmitted to facilitate the technical review being conducted by the Nuclear Regulatory Commission (NRC) staff and to support a conference call (if needed) with Exelon in order to clarify the licensees submittal. The draft RAI is related to Exelons submittal dated March 25, 2010, regarding Limerick Generating Station, Units 1 and 2, Measurement Uncertainty Recapture Power Uprate. The draft questions were sent to ensure that they were understandable, the regulatory basis was clear, and to determine if the information was previously docketed. Additionally, review of the draft RAI would allow Exelon to evaluate and agree upon a schedule to respond to the RAI. This memorandum and the attachment do not represent an NRC staff position.
Docket Nos. 50-352 and 50-353
Enclosure:
As stated
July 15, 2010 MEMORANDUM TO: Harold K. Chernoff, Chief Plant Licensing Branch I-2 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation FROM:
Peter Bamford, Project Manager /ra/
Plant Licensing Branch I-2 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation
SUBJECT:
LIMERICK GENERATING STATION, UNITS 1 AND 2 - ELECTRONIC TRANSMISSION, DRAFT REQUEST FOR ADDITIONAL INFORMATION REGARDING MEASUREMENT UNCERTAINTY RECAPTURE POWER UPRATE (TAC NOS. ME3589 AND ME3590)
The attached draft request for additional information (RAI) was transmitted by electronic transmission on July 8, 2010, to Mr. Kevin Borton, at Exelon Generation Company, LLC (Exelon). This draft RAI was transmitted to facilitate the technical review being conducted by the Nuclear Regulatory Commission (NRC) staff and to support a conference call (if needed) with Exelon in order to clarify the licensees submittal. The draft RAI is related to Exelons submittal dated March 25, 2010, regarding Limerick Generating Station, Units 1 and 2, Measurement Uncertainty Recapture Power Uprate. The draft questions were sent to ensure that they were understandable, the regulatory basis was clear, and to determine if the information was previously docketed. Additionally, review of the draft RAI would allow Exelon to evaluate and agree upon a schedule to respond to the RAI. This memorandum and the attachment do not represent an NRC staff position.
Docket Nos. 50-352 and 50-353
Enclosure:
As stated DISTRIBUTION:
Public RidsNrrPMLimerick LPL1-2 R/F Accession No.: ML101870024
- via memo OFFICE LPL1-2/PM EEEB/BC NAME PBamford RMathew*
DATE 07/15/2010 07/01/2010
OFFICIAL RECORD COPY
DRAFT Enclosure REQUEST FOR ADDITIONAL INFORMATION LIMERICK GENERATING STATION, UNITS 1 AND 2 MEASUREMENT UNCERTAINTY RECAPTURE (MUR)
POWER UPRATE REQUEST DOCKET NOS. 50-352 AND 50-353 By letter dated March 25, 2010 (Agencywide Documents Access and Management System (ADAMS) Accession No. ML100850380), Exelon Generation Company, LLC (Exelon, the licensee) submitted a license amendment request (LAR) proposing to revise the operating license and technical specifications for Limerick Generating Station (LGS), Units 1 and 2. This LAR proposes to implement an increase of approximately 1.65% in rated thermal power from the currently licensed thermal power limit of 3458 megawatts thermal. The increase would be based on the improved thermal power measurement accuracy, which would be achieved through the utilization of the Cameron International (formerly Caldon) CheckPlusTM leading edge flowmeter ultrasonic flow measurement instrumentation. The Nuclear Regulatory Commission staff has been reviewing the submittal and has determined that additional information is needed to complete its review.
- 1. The Generator Transient Stability Study (Attachment 12) of the LAR did not consider a LGS dual unit trip scenario and its impact on grid stability after the increased loading of the power uprate? Explain in detail why a LGS dual unit trip scenario after uprate was not considered and analyzed?
- 2. In the LAR, Attachment 1, Section 3.4.1, the licensee concludes that there will be a minor increase in normal power system loads. Provide a detailed discussion demonstrating that the minor increase in normal power system loads due to the uprate will not impact the degraded voltage relay (DVR) allowable value for loss of power covered by LGS, Unit 1 and 2, technical specification 3/4.3.3, Table 3.3.3-2.
- 3. In the LAR, Attachment 1, Section 3.4.1, the licensee concludes that there will be small increases in normal operational radiation levels. Discuss in detail how the small increases in normal operational radiation levels will not affect the existing equipment qualification (EQ) per 10 CFR 50.49.
- 4. In the LAR, Attachment 12, Section 4, of the Power Grid Uprate Voltage Analysis for LGS, the licensee states that in situation where voltage drops exceeded 0.03 per unit, additional analysis was performed to incorporate system adjustments between contingencies. Transformer taps and automatically switched capacitors were allowed to change to regulate voltage. Provide a detailed discussion about the load tap-changing transformers and automatic switched capacitor banks which were allowed to function automatically in the additional analyses. Clarify if these system adjustments and the transformer tap changes will result in any plant design modifications to ensure that voltage drop will not exceed 0.03 per unit.
DRAFT
- 5. The LAR, Attachment 61, Table 6-2, shows the main generators maximum nominal rating for the uprated condition as 1138.47 MWe [Megawatts electric] and 551.39 MVar [Megavolt-amp-reactive]. The main generators maximum nominal rating of 1138.47 MWe is significantly lower than the expected full load generator output value of 1240 MWe for winter following MUR power uprate, as specified in the LAR, 2, Appendix B page 2 of 5. Please explain how the main generators worst case (winter) expected MWe output can exceed the maximum nominal MWe rating.
- 6. Please specify the worst case MWe and MVar loadings on LGS, Unit 1 and 2 main generator step-up transformers for both existing and uprated conditions, and discuss how the uprated loading is within the capability of the transformers.
- 7. The LAR, Attachment 6, Section 10.3.1 states that the conservatism in the equipment qualifications were originally applied to the environmental parameters and no change is needed for the TPO uprate. Please discuss in detail what specific conservatism in the environmental parameters of the original EQ evaluations, when applied to uprated conditions, results in the existing EQ evaluations bounding the uprated normal and accident conditions.
- 8. Provide EQ profiles for the EQ areas where temperature and or pressure will increase due to uprate to demonstrate that the existing EQ profiles bound the uprated EQ profiles for both normal and accident conditions. In addition, confirm that the EQ margins required per IEEE-3232 for both inside and outside containment will be maintained for the uprated condition.
- 9. The LAR, Attachment 6, Section 10.3.1.1, states, Normal temperatures may increase slightly near the Feedwater and Reactor Recirculation lines and will be evaluated through the EQ temperature monitoring program Discuss the expected magnitude, and resulting expected impact, of the increased temperatures on the safety related equipment in the area.
1 Attachment 6 is a report by General Electric (GE)-Hitachi Nuclear Energy, NEDC-33484P, titled Safety Analysis Report for Limerick Generating Station Units 1 and 2 Thermal Power Optimization, Revision 0, dated March 2010. A non-proprietary version of this report (NEDO-33484, same title) is available at ADAMS Accession No. ML100850403.
2 The LGS Updated Final Safety Analysis Report provides a description of the LGS commitment to IEEE-323.