ML083430010
| ML083430010 | |
| Person / Time | |
|---|---|
| Site: | Calvert Cliffs  |
| Issue date: | 12/03/2008 |
| From: | Spina J Constellation Energy Group |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| TAC MD9554, TAC MD9555 | |
| Download: ML083430010 (8) | |
Text
(if, James A. Spina Calvert Cliffs Nuclear Power Plant, Inc.
Vice President 1650 Calvert Cliffs Parkway Lusby, Maryland 20657 410.495.5200 410.495.3500 Fax (Constellation Energy-Nuclear Generation Group December 3, 2008 U. S. Nuclear Regulatory Commission Washington, DC 20555 ATTENTION: Document Control Desk
SUBJECT:
Calvert Cliffs Nuclear Power Plant Unit Nos. I & 2; Docket Nos. 50-317 & 50-318 Response to Request for Additional Information - License Amendment for Measurement Uncertainty Recapture Power Uprate- Calvert Cliffs Nuclear Power Plant. Unit Nos. 1 and 2
REFERENCES:
(a) Letter from Mr. D. R. Bauder (CCNPP), to Document Control Desk (NRC) dated August 29, 2008, License Amendment Request: Appendix K Measurement Uncertainty Recapture - Power Uprate Request (b) Letter from Mr. D. V. Pickett (NRC) to Mr. J. A. Spina (CCNPP), dated October 3, 2008, Request for Additional Information Re: License Amendment for Measurement Uncertainty Recapture Power Uprate -
Calvert Cliffs Nuclear Power Plant, Unit Nos. I and 2 (TAC Nos.
MD9554 and MD9555)
In Reference (a), Calvert Cliffs Nuclear Power Plant, Inc. submitted a license amendment request to the Nuclear Regulatory Commission (NRC) for a measurement uncertainty recapture power uprate for Calvert Cliffs Nuclear Power Plant, Units 1 and 2. In Reference (b) the NRC requested additional information be submitted to support their review of the submittal. Our response to the Request for Additional Information Nos. 1.1, 1.3, 1.4, and 2.b are provided at this time in Attachment (1). Responses for the remaining Request for Additional Information from Reference (b) will be provided, as requested, by December 31, 2008.
tZDR U
Document Control Desk December 3, 2008 Page 2 Should you have questions regarding this matter, please contact Mr. Jay S. Gaines at (410) 495-5219.
Very trul urs, STATE OF MARYLAND
- TO WIT:
COUNTY OF CALVERT I, James A. Spina, being duly sworn, state that I am Vice President - Calvert Cliffs Nuclear Power Plant, Inc. (CCNPP), and that I am duly authorized to execute and file this License Amendment Request on behalf of CCNPP. To the best of my knowledge and belief, the statements contained in this document are true and correct. To the extent that these statements are not based on my personal knowledge, they are based upon information provided by other CCNPP employees and/or consultants. Such information has been reviewed in accordance with company practice and I believe i e.relia e 7
/n /
, Jt'..,,7 Subscribed and sworn before me a Notary) ublic ip and for the State of Maryland and County of
,this 5 day of k e'Cern 2008.
WI'TNESS rfiy Hand and Notarial Seal:
Notary Publici My Commission Expires:
Date JAS/KLG/bjd
Attachment:
(1) Response to Request for Additional Information dated October 3, 2008 -
Measurement Uncertainty Recapture Power Uprate
Enclosure:
(1) Engineering Report CCN-IR-08001, "Allowed Outage Time (AOT)
Justification Report, Appendix K Uprate Project," Revision 0 (2) BG&E Calculation CA00800, "Total Loop Uncertainty for the Plant Computer's Determination of Main Feedwater Pump Discharge Pressure," Revision I
Document Control Desk December 3, 2008 Page 3 cC: D. V. Pickett, NRC Resident Inspector, NRC S. J. Collins, NRC S. Gray, DNR
ATTACHMENT (1)
RESPONSE TO REQUEST FOR ADDITIONAL INFORMATION DATED OCTOBER 3, 2008 -
MEASUREMENT UNCERTAINTY RECAPTURE POWER UPRATE Calvert Cliffs Nuclear Power Plant, Inc.
December 3, 2008
ATTACHMENT (1)
RESPONSE TO REQUEST FOR ADDITIONAL INFORMATION DATED OCTOBER 3,2008 -
MEASUREMENT UNCERTAINTY RECAPTURE POWER UPRATE In the application dated August 29, 2008, Page 8, Section 1.7 of Attachment 2, lists the following six conditions that will trigger a plant computer alarmfor the leadingedgeflow meter (LEFM)meter status:
" failure of one or more transducerpaths,
- velocityprofile out-of-limits,
" analog input out-of-limits,
- system uncertainty out-of-limits,
- loss ofcomnunicationfrom the LEFMCheckPlus System to the Plant Computer,
- cabinet temperatureexceeds limit, The following three outage times areproposedfor the above alarms:
a) If the LEFM CheckPlus System is in a degradedcondition with the plant computer available to perform the secondarycalorimetriccalculation,the allowable outage time is 30 days.
b) If the LEFM CheckPlus System is out of service (OOS) with the plant computer available to perform the secondary calorimetriccalculation, the allowable outage time is 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />, provided steady-state conditions exist. Steady-state conditions are defined as power variations of less than 10 percentfrom the initialpower level when the system is declared OOS.
c) If the plant computer is unavailable or if another input to the secondary calorimetriccalculation fails (other than the LEFM CheckPlus System), the allowable outage thne is less than or equal to 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />.
BALMl:
Please identify which of those six alarm conditions are "Failed"conditions that cause the LEFM to be OOS and which are the "Alert' conditionsfor degradedstatus, and explain the reasonsfor this division.
CCNPP Response:
Each of the Caldon LEFM CheckPlus systems to be installed consists of two spool piece measurement sections with one section installed in the feedwater header to each steam generator. Each Caldon LEFM CheckPlus spool piece measurement section consists of two planes of ultrasonic transducers. Each feedwater header also has two pressure transmitters, used for calculation of the mass flow rate, and a dual element resistance temperature detector (RTD), which is u~ed whenever temperature is below 250O in order to provide accurate temperature readings at low feedwater temperatures. At temperatures above 2500, temperature is accurately measured via measured sound velocity from the ultrasonic transducers.
However below approximately 2501F, the temperature algorithm, developed from the ultrasonic transducers inputs, produces two possible solutions for the temperature. At this point the dual element RTD input is needed to resolve the ultrasonic temperature algorithm in order to provide an accurate temperature indication.
The Caldon LEFM CheckPlus system is capable of supporting an Appendix K uprate up to 1.7%,
depending on the results of site specific uncertainty analysis (Reference 1). The Caldon LEFM Check spool piece, which consists of only one plane of ultrasonic transducers, is capable of supporting an Appendix K uprate up to 1.4% (Reference 2). Hence, the Caldon LEFM CheckPlus spool piece is essentially the combination of two Caldon LEFM Check spool pieces.
In an "Alert" condition, one plane of transducers is fully operational while the second set of transducers is in a degraded condition. The measured flow is based upon only the fully operational set of transducers. Consequently, in an "Alert" condition, the Caldon LEFM CheckPlus system is bound by I
ATTACHMENT (1)
RESPONSE TO REQUEST FOR ADDITIONAL INFORMATION DATED OCTOBER 3,2008 -
MEASUREMENT UNCERTAINTY RECAPTURE POWER UPRATE the uncertainties of the Caldon LEFM Check system and is the basis for the 30 day Allowable Outage Time (AOT) for operation in an "Alert" condition. In a "Failed" condition, either both planes of transducers are operating in a degraded condition or there is some other system failure that could result in operation outside the site specific uncertainty analysis.
Each alarm condition is described below:
Failure of One or More Transducer Paths - If the failed transducer path(s) are in only one plane of transducers, the Caldon LEFM CheckPlus system is in an "Alert" status. If there are two or more failures, with at least one failure per transducer plane, the Caldon LEFM CheckPlus system is in a "Failed" status.
Velocity Profile Out-of-Limits - The Caldon LEFM CheckPlus system is in a "Failed" status. If velocity profile is out-of-limits, the velocity profile is not within the conditions established in the site specific uncertainty analysis. The velocity profile test is based upon the planes used for flow measurement. Therefore, if there are no transducer failures, the test is based upon the transducers in both planes. If transducers have failed in only one plane, the test is based upon the remaining plane.
If there are transducer failures in both planes, the velocity test is not required as the system is already in a "Failed" status.
Analog Input Out-of-Limits - If both pressure inputs for a header have failed, flow cannot be calculated and the system is in a "Failed" status.
If both RTD inputs fail, when feedwater temperature is above - 2501, the RTD inputs are not necessary for accurate temperature measurement and the system is in an "Alert" status.
If both RTD inputs fail, when feedwater temperature is below - 2500, the RTD inputs are necessary for accurate temperature measurement and the system is in a "Failed" status.
If one pressure input or one temperature input for a header has failed, the system is in an "Alert" status as the other input is available.
If both pressure inputs are working but do not compare within alarm limits or both temperature inputs are working but do not compare within alarm limits, the system is in "Alert" status. The more conservative value (lower pressure or lower temperature) is used in the calculation of feedwater flow.
System Uncertainty Out-of-Limits - As the name infers, the results of this diagnostic test are applied to the entire Caldon LEFM CheckPlus system. The system is in a "Failed" status.
Loss of Communication from the Caldon LEFM CheckPlus System to the Plant Computer - If communication is lost, the secondary calorimetric calculation using the Caldon LEFM CheckPlus system will not update. Therefore, the system is in a "Failed" status.
Cabinet Temperature Exceeds Limit - If either cabinet temperature exceeds the alarm limit, then the cabinet electronics are conservatively assumed to be adversely affected such that the accuracy of the flow calculation is not considered to be bounded by the vendor report for Caldon LEFM CheckPlus system uncertainty. The system is in a "Failed" status.
2
ATTACHMENT (1)
RESPONSE TO REQUEST FOR ADDITIONAL INFORMATION DATED OCTOBER 3,2008 -
MEASUREMENT UNCERTAINTY RECAPTURE POWER UPRATE IAILL3:
Based on the transmitter drift record at the plant please provide the calculated effect of the transmitter drift on power calorimetricduringthe proposed 72 hour8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> A OT when the LEFM CheckPlus system is out of service.
CCNPP Response:
A drift study of the feedwater flow transmitters was performed and is included as Enclosure (1). The results of the drift study demonstrate that the bounding drift for a feedwater flow transmitter for a 72 hour8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> AOT is +/- 0.0206% of span expressed in differential pressure. Conservatively assuming that the feedwater flow transmitters drift in the same direction on both feedwater headers, the net impact on calorimetric power is only 0.34 MWth, or 0.0124% Rated Thermal Power (RTP). If the transmitters drift randomly, the net impact on calorimetric power is 0.24 MWth or 0.0087% RTP.
RALL4:
What is meant by "another input to the secondary calorimetriccalculationfails (other than the LEFM CheckPlus System)?" Does it mean failure of the LEFM together with another input orfailure of two inputs while the LEFM is operable?
CCNPP Response:
The uncertainty of the secondary plant calorimetric to support the Appendix K uprate is based upon the calculation of calorimetric power using the following inputs:
- Feedwater flow, provided by the Caldon LEFM CheckPlus system and communicated to the plant computer,
- Feedwater temperature, provided by the Caldon LEFM CheckPlus system and communicated to the plant computer,
" Feedwater pressure, provided by pressure transmitter inputs to the Caldon LEFM CheckPlus system and communicated to the plant computer,
" Main steam pressure, provided from a conventional 4-20 mA DC instrument loop,
- Blowdown flow, manually input to the plant computer by Operations personnel based upon local readings of blowdown tank effluent flow.
The proposed 24 hour2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> outage time is only applicable to failure of the plant computer or failure of the inputs that are not provided by the Caldon LEFM CheckPlus system, specifically the main steam pressure input. If the blowdown tank effluent flow cannot be verified locally, blowdown flow can be secured and the manual input set to zero.
The proposed 24 hour2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> outage time does not apply to the status (Operable/Alert/Fail) of the Caldon LEFM CheckPlus system.
RAL2J:
- 2. Please submit the following reports in order to verify the assumptions used in the calorimetric uncertaintycalculation:
b) Selection and evaluation of the pressureinstrumentation 3
ATTACHMENT (1)
RESPONSE TO REQUEST FOR ADDITIONAL INFORMATION DATED OCTOBER 3,2008 -
MEASUREMENT UNCERTAINTY RECAPTURE POWER UPRATE CCNPP Response:
The selected transmitters must have an uncertainty of less than or equal to +/- 15 psi to satisfy the requirements of Reference 1. Rosemount 3051CG5 series transmitters will be used for pressure input to the Caldon LEFM CheckPlus system. The transmitters receive power from the Caldon LEFM CheckPlus system cabinet and provide input directly to the cabinet. These transmitters are identical to transmitters already used to measure feedwater pump discharge pressure. Design Calculation CA00800 (Enclosure 2), performed for the feedwater pump discharge pressure transmitters, calculated transmitter uncertainty as +/- 0.45% span. The new instruments are spanned between 0 and 1300 psig, resulting in a transmitter uncertainty of +/- 5.85 psi.
A feedwater flow uncertainty calculation to be submitted in our response to RAI 2.c includes, along with transmitter uncertainty, the contribution to uncertainty from the analog-to-digital converter in the Caldon LEFM CheckPlus system. The results of this calculation are expected to be bounded by Reference 1.
References
- 1. Caldon ER-I 57P, "Supplement to Topical Report ER-80P: Basis for a Power Uprate with the LEFM Check or CheckPlus System," Revision 5, dated October 2001, approved by NRC SER, dated December 20, 2001
- 2. Caldon ER-80P, "Improving Thermal Power Accuracy and Plant Safety While Increasing Operating Power Level Using the LEFM Check System," dated March 1997 approved by NRC SER, dated March 8, 1999 Enclosures (1) Engineering Report CCN-IR-08001, "Allowed Outage Time (AOT) Justification Report, Appendix K Uprate Project," Revision 0 (2) BG&E Calculation CA00800, "Total Loop Uncertainty for the Plant Computer's Determination of Main Feedwater Pump Discharge Pressure," Revision I 4