ML11208C509
| ML11208C509 | |
| Person / Time | |
|---|---|
| Site: | Harris  |
| Issue date: | 07/27/2011 |
| From: | Mozafari B Division of Operating Reactor Licensing |
| To: | Caves J Progress Energy Co |
| Brenda Mozafari, NRR/DORL, 301-415-2020 | |
| References | |
| TAC ME6169 | |
| Download: ML11208C509 (5) | |
Text
1 NRR-PMDAPEm Resource From:
Mozafari, Brenda Sent:
Wednesday, July 27, 2011 2:16 PM To:
'Caves, John'; 'Bass, Kimberly' Cc:
Saba, Farideh; Alexion, Thomas
Subject:
- John, By letter dated April 28, 2011 (Agencywide Documents Access and Management System (ADAMS) Accession No. ML11124A180), Carolina Power & Light Company (the licensee) requested approval from the U.S. Nuclear Regulatory Commission (NRC) to increase the core thermal power level of Shearon Harris Nuclear Power Plant (HNP), Unit 1 from 2,900 megawatts thermal (MWt) to 2,948 MWt, an increase of approximately 1.66%
over the present licensed power level and to change the power plant technical specifications accordingly.
The NRC staff has reviewed the licensees submittals and determined that the following additional information is needed to complete the review.
The NRC requests that the licensee respond to this request for additional information (RAl) within 30 days of the date of this email. If the licensee concludes that more than 30 days are required to respond to the RAl, the licensee should request additional time, including a basis for why the extension is needed.
Contact me at the number below or by e-mail if you have any questions on this issue or if you require additional time to submit your response.
Brenda L. Mozafari Senior Project Manager Robinson and Harris Nuclear Plants 301-415-2020 REQUEST FOR ADDITIONAL INFORMATION SHEARON HARRIS UNIT 1, LICENSE AMENDMENT REQUEST MEASUREMENT UNCERTAINTY RECAPTURE POWER UPRATE (TAC NO. ME6169)
Regulatory Basis Nuclear power plants are licensed to operate at a specified core thermal power. Appendix K, ECCS Evaluation Models, to Title 10 of the Code of Federal Regulations (10 CFR) Part 50, Domestic Licensing of Production and Utilization Facilities, requires loss-of-coolant accident and emergency core cooling system (ECCS) analyses to assume that the reactor has been operating continuously at a power level at least 102%
of the licensed thermal power level to allow for instrumentation uncertainties. Alternatively, Appendix K allows such analyses to assume a value lower than the specified 102 percent, but not less than the licensed thermal power level, provided the proposed alternative value has been demonstrated to account for uncertainties due to power level instrumentation error. This allowance gives licensees the option of justifying a power uprate with reduced margin between the licensed power level and the power level assumed in the ECCS analysis by using more accurate instrumentation to calculate the reactor thermal power.
2 Because the maximum power level of a nuclear plant is a licensed limit, the NRC must review and approve a proposal to raise the licensed power level under the license amendment process. The LAR should include a justification for the reduced power measurement uncertainty to support the proposed power uprate.
The licensee developed the format of their submittal for the proposed power uprate based on the guidance of Regulatory Issue Summary (RIS) 2002-03, Guidance on the Content of Measurement Uncertainty Recapture Power Uprate Applications, dated January 31, 2002. The NRC staff is evaluating the LAR using the provisions outlined in RIS 2002-03 as guidance.
Questions
- 1. In the LAR, Enclosure 2, page 18, section I.1.H Actions for Exceeding Completion Time and Technical Basis, the licensee described the LEFM CheckPlus modes of operation: Normal and Maintenance. The licensee defines the loss of a single flow plane on a single feedwater line or multiple feedwater lines as Maintenance Mode.
The licensee states that the thermal power uncertainty associated with the LEFM CheckPlus system in Normal mode is 0.34%. When the system is in Maintenance mode, the calculated thermal power uncertainty is stated as being 0.48%, regardless of whether a single flow plane is lost on one or multiple feedwater lines.
Hence, Maintenance mode encompasses three possible scenarios:
1-Loss of a single flow plane on one feedwater line.
2-Loss of a single flow plane on two feedwater lines.
3-Loss of a single flow plane on all three feedwater lines.
Explain which of the above scenarios was used by Cameron Engineering to calculate the thermal power uncertainty of 0.48%. State whether it was calculated based on the loss of a single flow plane on one feedwater line or based on the loss of a single flow plane on all three feedwater lines.
- 2. In the LAR, Enclosure 2, page 19, section I.1.H Actions for Exceeding Completion Time and Technical Basis, the licensee described the LEFM CheckPlus Fail mode. One event that would lead to the system entering Fail mode is the loss of both flow planes (A and B) on a single feedwater line or multiple feedwater lines.
2.a. Explain what mode would be entered if flow plane A became inoperable in one feedwater line and flow plane B became inoperable on a different feedwater line.
2.b. Explain how the licensee can identity which flow plane is the A plane and which is the B plane.
If a single flow plane fails on two different feedwater lines, describe how would the licensee know which planes failed (i.e. two A planes, two B planes, or one A and one B plane).
- 3. In the LAR, Enclosure 2, page 17, section I.1.G Completion Time and Technical Basis, the licensee states: A completion time of 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> is proposed for operation at any power level above the current licensed power of 2900 MWt with the LEFM not fully functional.
Plant operation at any power level above the current licensed power of 2900 MWt with the LEFM not fully functional for a determined period of time is only acceptable if steady-state conditions persist throughout that period.
3 3.a. Explain if the proposed completion time for operation at any power level above the current licensed power of 2900 MWt with the LEFM not fully functional is dependent on the plant maintaining steady-state conditions throughout the selected period.
3.b. Explain what the maximum permitted power level will be if, while in Maintenance mode, the plant experiences a power decrease below 2900 MWt. Provide a justification for this action.
3.c. Explain what the maximum permitted power level will be while in Maintenance mode if, before entering Maintenance mode, the plant rated thermal power was less than 2900 MWt. Provide a justification for this action.
- 4. In the LAR, Enclosure 1, the licensee proposed changes to the following functions found in Technical Specifications (TS) Table 2.2-1 Reactor Trip System Instrumentation Trip Setpoint:
Functional Unit Current Value MUR Value Power Range Neutron Flux - High Setpoint Total Allowance 7.5 5.83 Trip Setpoint 109% of RTP 108% of RTP Allowable Value 111.1% of RTP 109.5% of RTP Power Range Neutron Flux - Low Setpoint Total Allowance 8.3 7.83 Allowable Value 27.1% of RTP 26.8% of RTP Power Range Neutron Flux - High Positive Rate Total Allowance 2.5 2.33 Power Range Neutron Flux - High Negative Rate Total Allowance 2.5 2.33 The licensee also stated that the safety analysis limit (SAL) for the Power Range Neutron Flux High Setpoint was reduced from 118% to 117% of current rated thermal power.
4.a. Provide summary calculations for the TS changes listed in the table above including the determination of Total Loop Uncertainty, Nominal Trip Setpoint, Allowable Value, As-Found and As-Left Tolerances, if applicable, and a description of the methodology used to make the calculations.
4.b. Provide summary calculations for the Power Range Neutron Flux High Setpoint SAL including the Total Loop Uncertainty, Nominal Trip Setpoint, Allowable Value, As-Found Tolerance and As-Left Tolerances, if applicable, and a description of the methodology used to make the calculation.
4.c. Confirm whether the Trip Setpoint in TS Table 2.2-1 is the Nominal Trip Setpoint. If not, describe to what it refers.
- 5. The licensee also proposed to add the following two notes to TS table 2.2.-1:
Note 7: If the as-found channel setpoint is outside its predefined as-found tolerance, then the channel shall be evaluated to verify that it is functioning as required before returning the channel to service.
Note 8: The instrument channel setpoint shall be reset to a value that is within the as-left tolerance around the Nominal Trip Setpoint (NTSP) at the completion of the surveillance; otherwise, the channel shall be declared inoperable. NTSPs more conservative than the Trip Setpoints in Table 2.2.1 are acceptable provided that the as-found and as-left tolerances apply to the actual setpoint implemented in the surveillance procedures (field setting) to confirm channel performance. The methodologies used to determine NTSPs and the as-found and the as-left
4 tolerances are specified in Progress Energy procedure EGR-NGGC-0153, "Engineering Instrument Setpoints."
5.a. Explain the bases for adding these notes.
5.b. Explain what is meant by the terms as-found and as-left tolerances. Also, describe the methods used to determine their appropriate magnitude.
5.c. Describe where Progress Energy procedure EGR-NGGC-0153, "Engineering Instrument Setpoints," is referenced in the FSAR.
5.d. Submit Progress Energy procedure EGR-NGGC-0153, "Engineering Instrument Setpoints," for NRC staff evaluation
Hearing Identifier:
NRR_PMDA Email Number:
116 Mail Envelope Properties (9C2386A0C0BC584684916F7A0482B6CA2F2B1E08B9)
Subject:
MUR RAI (EICB).docx Sent Date:
7/27/2011 2:15:57 PM Received Date:
7/27/2011 2:15:00 PM From:
Mozafari, Brenda Created By:
Brenda.Mozafari@nrc.gov Recipients:
"Saba, Farideh" <Farideh.Saba@nrc.gov>
Tracking Status: None "Alexion, Thomas" <Thomas.Alexion@nrc.gov>
Tracking Status: None
"'Caves, John'" <john.caves@pgnmail.com>
Tracking Status: None
"'Bass, Kimberly'" <Kimberly.Bass@pgnmail.com>
Tracking Status: None Post Office:
HQCLSTR02.nrc.gov Files Size Date & Time MESSAGE 9698 7/27/2011 2:15:00 PM Options Priority:
Standard Return Notification:
No Reply Requested:
No Sensitivity:
Normal Expiration Date:
Recipients Received:
ZZZ