ML12132A086
| ML12132A086 | |
| Person / Time | |
|---|---|
| Site: | Calvert Cliffs  |
| Issue date: | 05/07/2012 |
| From: | George Gellrich Calvert Cliffs |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| Download: ML12132A086 (5) | |
Text
George H. Gellrich Calvert Cliffs Nuclear Power Plant, LLC Vice President 1650 Calvert Cliffs Parkway Lusby, Maryland 20657 410.495.5200 410.495.3500 Fax CENG.
a joint venture of Om*-*au" eDF CALVERT CLIFFS NUCLEAR POWER PLANT May 7, 2012 U. S. Nuclear Regulatory Commission Washington, DC 20555 ATTENTION: Document Control Desk
SUBJECT:
Calvert Cliffs Nuclear Power Plant Unit Nos. 1 & 2; Docket Nos. 50-317 & 50-318 Responses to Request for Additional Information Regarding Diesel Generator Surveillance Requirement 3.8.1.11
REFERENCES:
(a) Letter from Mr. G. H. Gellrich (CCNPP) to Document Control Desk (NRC), dated August 8, 2011, License Amendment Request: Diesel Generator Surveillance Requirement 3.8.1.11 Revision (b) Letter from Mr. D. V. Pickett (NRC) to Mr. G. H. Gellrich (CCNPP),
dated March 8, 2012, Request for Additional Information Re: Diesel Generator Technical Specification Surveillance Requirement 3.8.1.11 -
Calvert Cliffs Nuclear Power Plant, Unit Nos. 1 and 2 (TAC Nos. ME6831 and ME6832)
In Reference (a), Calvert Cliffs Nuclear Power Plant, LLC (Calvert Cliffs) submitted a license amendment request to revise Technical Specification Surveillance Requirement 3.8.1.11 by revising the required power factor value to be achieved by the diesel generators during conduct of the surveillance test. In Reference (b), the Nuclear Regulatory Commission issued a request for additional information to support their review of Calvert Cliffs' license amendment request. Attachment (1) contains Calvert Cliffs' response to the request for additional information.
Document Control Desk May 7, 2012 Page 2 Should you have questions regarding this matter, please contact Mr. Douglas E. Lauver at (410) 495-5219.
Very truly yours, STATE OF MARYLAND
- TO WIT:
COUNTY OF CALVERT I, George H. Gellrich, being duly sworn, state that I am Vice President - Calvert Cliffs Nuclear Power Plant, LLC (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 it to be reliable.
Subscribed and sworn before me a Notary Pu lic in and for the State of Maryland and County of
,, , ,, this _1 day of /y ,2012.
WITNESS my Hand and Notarial Seal:
- Notary Public My Commission Expires: Cý/!Z~d DWte GHG/KLG/bjd
Attachment:
(1) Calvert Cliffs Response to NRC Request for Additional Information cc: N. S. Morgan, NRC Resident Inspector, NRC W. M. Dean, NRC S. Gray, DNR
ATTACHMENT (1)
CALVERT CLIFFS RESPONSE TO NRC REQUEST FOR ADDITIONAL INFORMATION Calvert Cliffs Nuclear Power Plant, LLC May 7, 2012
ATTACHMENT (1)
CALVERT CLIFFS RESPONSE TO NRC REQUEST FOR ADDITIONAL INFORMATION The NRC staff has reviewed the information provided in the licensee's letter dated January 11, 2012 (Agencywide Documents Access and Management System Accession No. ML12012A218). The staff needs the following additional information with regard to the Calvert Cliffs Nuclear Power Plant (CCNPP)Response #1.
The CCNPP UpdatedFinalSafety Analysis Report Chapter 8.0 provides the design basis of the electrical system and states that CCNPP has four safety-related emergency diesel generators (EDGs), two dedicated to each unit. Any combination of two of the EDGs (one from each unit) is capable of supplying sufficient powerfor the operation of necessary engineeredsafety feature loads during accident conditions on one unit and shutdown loads of the alternate unit concurrentwith a loss of offsite power, andfor the safe and orderly shutdown of both units under loss of offsite power conditions.
(a) Confirm that the worst case EDG loadingis accountedfor in the highest values providedfor various design basis scenarios identified in CCNPPResponse #1.
Calvert Cliffs Response:
As stated in Response #1 of Reference 1, Table 1 represents the highest calculated diesel generator values of real and reactive power loading for various design basis scenarios. The calculation computes values for different time frames for each scenario, but the values listed in the table are the highest calculated at any time period throughout each scenario. The values also include loads that may be added manually via plant controlled procedures and pumps that may be in runout condition. The values do not, however, account for load variations due to changes in frequency or voltage from nominal values.
(b) Provide the impact on EDG loading (realand reactivepower) due to voltage variation that is allowed per technical specification (TS) surveillancerequirements (SRs).
Calvert Cliffs Response:
The EDG load calculation does not currently address real and reactive power load changes due to voltage variations. The majority of loads on the EDGs are induction motors which are considered to be constant kVA type loads. For these type loads, the kW and kVAR loading is not expected to vary with the small voltage variation (4060 to 4400 volts) allowed by EDG SRs, thus any total EDG load variation is expected to be very small.
(c) According to SR 3.8.1.11, EDG 2B is tested at 3000 kilo Watts (kW). However, the worst case large-break loss-of-coolant accident loading can be 2911 x 1.06 =3085.7 kW after taking into account TS allowed frequency variation of plus 1.2 Hz. Justify why the EDG load test values do not take into account the potential higher loadingas a consequence of allowed TSfrequency variation.
Calvert Cliffs Response:
Surveillance Requirement 3.8.1.11 is established to demonstrate the EDGs capability to operate at loads greater than predicted accident loads. As such the acceptance criteria for SR 3.8.1.11 is based on ensuring the EDG is able to handle all necessary loads for any Updated Final Safety Analysis Report (UFSAR) Chapter 14 accident and which does not exceed the EDG continuous rating value. The calculation that establishes the technical specification requirement does not inc'lude additional loading due to frequency variation as Calvert Cliffs is unaware of any regulatory requirement to do so per our licensing basis.
However while the UFSAR Chapter 14 accident loading establishes the acceptance criteria for the surveillance requirement, the EDGs are allowed to be loaded during the surveillance test to a level beyond the design basis accident loading level. The three Fairbanks Morse EDGs (IB, 2A, and 2B), are operated I
ATTACHMENT (1)
CALVERT CLIFFS RESPONSE TO NRC REQUEST FOR ADDITIONAL INFORMATION at up to 3300 KW (their accident loading is less than 3000 KW) while the Societe Alsacienne De Constructions Mecaniques De Mulhouse EDG (1A) is run at up to 5400 KW (its accident loading is less than 4000 KW). This demonstrates the EDGs capability to handle additional loads due to variations in frequency or voltage allowed by the Technical Specifications.
(d) The CCNPPResponse #1 indicates thatplantproceduresprovide guidancefor operationspersonnel to manually add loads to the operatingEDG(s). Provide details on guidance and limitations providedto plant operators to load the EDGs duringplant emergencies. Validate that the proposed surveillance testing will envelop the worst case postulated loadingtaking into account all operator actions.
Calvert Cliffs Response:
The proposed change to the required EDG power factor to be achieved in SR 3.8.1.11 aligns its value to the calculated design basis power factor value experienced during worst case UFSAR Chapter 14 accident conditions. The technical specifications will therefore ensure required safety related equipment can support functions required by UFSAR Chapter 14 analyses. There is no technical specification requirement that the EDGs be tested for all possible system operations that encompass all possible operator actions.
An example of guidance provided to operators on loading additional loads onto the EDGs can be found in Calvert Cliffs emergency operating procedure for loss-of-offsite power which cautions:
There is a possibility for excessive lB Diesel Generator (DG) loading if a safety injection actuation signal is received and the loss-of-coolant incident sequencer actuates. To prevent this from occurring, the operator should NOT energize any non-essential loads unless specifically allowed within this procedure. The maximum steady-state lB DG load limit is 3300KW, the IA DG load limit is 5400 KW.
In addition this loss-of-offsite power emergency operating procedure also directs operators that if a safety injection actuation signal occurs they should check EDG loading. Then if EDG loading is too high, the procedure directs the operators to remove specific loads in order to lower EDG loading below steady-state EDG load limits.
REFERENCE:
- 1. Letter from Mr. G. H. Gellrich (CCNPP) to Document Control Desk (NRC), dated January 11, 2012, Responses to Request for Additional Information Regarding Diesel Generator Surveillance Requirement 3.8.1.11 2