ML13189A130
| ML13189A130 | |
| Person / Time | |
|---|---|
| Site: | Calvert Cliffs  |
| Issue date: | 07/01/2013 |
| From: | Flaherty M Constellation Energy Nuclear Group |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| Download: ML13189A130 (9) | |
Text
Calvert Cliffs Nuclear Power Plant 1650 Calvert Cliffs Parkway Lusby, Maryland 20657 CENG a joint venture of Constellation Energy, D CALVERT CLIFFS NUCLEAR POWER PLANT July 1, 2013 U. S. Nuclear Regulatory Commission Washington, DC 20555 ATTENTION: Document Control Desk
SUBJECT:
Calvert Cliffs Nuclear Power Plant Unit Nos. I and 2; Docket Nos. 50-317 and 50-318 Response to Request for Additional Information Regarding Adoption of TSTF-501-A, Revision 1, "Relocate Stored Fuel Oil and Lube Oil Volume Values to Licensee Control"
REFERENCES:
(a) Letter from Mr. G. H. Gellrich (CCNPP) to Document Control Desk (NRC), dated October 2, 2012, Application for Technical Specification Improvement to Adopt TSTF-501-A, Revision 1, "Relocate Stored Fuel Oil and Lube Oil Volume Values to Licensee Control" (b) Letter from Ms. N. S. Morgan (NRC) to Mr. G. H. Gellrich (CCNPP),
dated May 31, 2013, Request for Additional Information Regarding Adoption of TSTF-501 -A, Revision 1, "Relocate Stored Fuel Oil and Lube Oil Volume Values to Licensee Control" License Amendment (TAC No. ME9794 and ME9795)
In Reference (a), Calvert Cliffs Nuclear Power Plant, LLC submitted a license amendment request to revise Technical Specification 3.8.3, "Diesel Fuel Oil" and Technical Specification 3.8.1, "AC Sources-Operating" by relocating the current fuel oil numerical volume requirements from the Technical Specifications to the Technical Specification Bases. In Reference (b), the Nuclear Regulatory Commission requested additional information to support their review of Reference (a). Attachment (1) provides the responses to the Nuclear Regulatory Commission's request for additional information contained in Reference (b).
These responses do not change the No Significant Hazards Determination provided in Reference (a). No regulatory commitments are contained in this letter.
Document Control Desk July 1, 2013 Page 2 Should you have questions regarding this matter, please contact Mr. Douglas E. Lauver at (410) 495-5219.
I declare under penalty of perjury that the foregoing is true and correct. Executed on July 1, 2013.
Very truly yours, Mark D. Flaherty Plant General Manager MDF/PSF/bjd Attachments: (1) Response to Request for Additional Information Regarding Adoption of TSTF-501-A, Revision 1, "Relocate Stored Fuel Oil and Lube Oil Volume Values to Licensee Control" (2) Technical Specification Bases Pages B 3.8.1-26 and B 3.8.1-34 cc: N. S. Morgan, NRC Resident Inspector, NRC W. M. Dean, NRC S. Gray, DNR
ATTACHMENT (1)
RESPONSE TO REQUEST FOR ADDITIONAL INFORMATION REGARDING ADOPTION OF TSTF-501-A, REVISION 1, "RELOCATE STORED FUEL OIL AND LUBE OIL VOLUME VALUES TO LICENSEE CONTROL" Calvert Cliffs Nuclear Power Plant, LLC July 1, 2013
ATTACHMENT (1)
RESPONSE TO REQUEST FOR ADDITIONAL INFORMATION REGARDING ADOPTION OF TSTF-501-A, REVISION 1, "RELOCATE STORED FUEL OIL AND LUBE OIL VOLUME VALUES TO LICENSEE CONTROL" NRC RAI 1:
The LAR identifies a deviationfr-om TSTF-501, in that, the licensee requests a revision to TS 3.8.1, "AC Sources-Operating" using a similar approach to the revision of TS 3.8.3 as described in the TSTF. The revision to TS 3.8.1 involves the modification of Surveillance Requirement (SR) 3.8.1.5 by replacing the specific day tank numerical volume requirement with the requirementto maintain greater than or equal to a one-hour supply offuel oil. The proposedrevision relocates the specific volume needed to support this requirement to the TS Bases. Pursuant to TSTF-501, the modification of SR 3.8.3.1 requires the licensee to make a specific reference to the methods and standards used to calculate the required numerical volume offuel oil. As such, a similar modification using the same approach as TSTF-501 should contain a similarreference to the methods and standards used to calculate the requirednumerical volume offuel oil.
The NRC staff requests that the licensee provide the methods and standardsused to calculate the required numerical volume of fuel oil stated in the proposed revision of TS SR 3.8.1.5. If the methods and standardsdiffer firom those discussed in TSTF-501, provide a technicaljustification.
CCNPP RAI 1 Response:
The marked up Technical Specification Bases provided in Reference 1 did not provide a reference to the method of calculating the required day tank stored diesel fuel oil volume equivalent to a one hour supply.
The method provided in American National Standards Institute (ANSI) N195-1976, Section 5.4, as endorsed by Regulatory Guide 1.137, Revision 1, Section C. 1.c, is used to calculate the required day tank stored diesel fuel oil volume equivalent to a one hour supply. Calvert Cliffs uses the "conservative" calculational method described by ANSI N 195-1976, Section 5.4 to calculate the required day tank stored diesel fuel oil volume. These references are added to the marked up Technical Specification Bases as shown in Attachment (2). Please replace the previously provided Technical Specification Bases markup for Surveillance Requirement 3.8.1.5 with the attached pages. Additionally, note that the diesel generator day tank volume meets the requirements of ANSI N195-1976, Section 6.1, to provide at least 60 minutes of operation based on the fuel consumption at 100% of the continuous rating of the diesel generator plus a margin of 10%.
NRC RAI 2:
The first bullet in Section 2. 0 "ProposedChange" states that, "The TS is modified so that Conditions A, B, or C are entered when the stored dieselfuel oil inventory is less than a 7-day supply, but greater than a 6-day supply for a diesel generator." However, in the mark-up version of the TS, a unit must enter Condition A when the stored dieselfiel oil inventory is less than a 7-day supply, but greater than a 6-day supply. A unit must enter Conditions B or C whenever the stored dieselfuel oil inventory is less than a 7-day supply (no greater than 6 day bound). This discrepancy affects the time allowed to restore the fiel oil to within requiredlimits before the unit must declare the affected diesel generator(DG) inoperable.
If the licensee modifies the TS as described in Section 2.0, then a fuel oil volume of less than a 6-day supply in the Unit 1 or 2 fiuel oil storage tank (FOST)21 would require entrance into Condition F and result in an immediate declaration of inoperablefor the affected DG. However, if the licensee modifies the TS as shown in the TS mark-ups, then the licensee would have up to 48 hours5.555556e-4 days <br />0.0133 hours <br />7.936508e-5 weeks <br />1.8264e-5 months <br /> to restore the fuel oil to within the requiredlimit before the unit must declare the affected DG inoperable.
I
ATTACHMENT (1)
RESPONSE TO REQUEST FOR ADDITIONAL INFORMATION REGARDING ADOPTION OF TSTF-501-A, REVISION 1, "RELOCATE STORED FUEL OIL AND LUBE OIL VOLUME VALUES TO LICENSEE CONTROL" The NRC staff requests that the licensee provide clarificationas to how the licensee intends to modify the TS. Specifically, whether a unit must enter Conditions B or C at any range offuel oil inventory less than a 7-day supply or if a unit must enter Conditions B or C only when the fuel oil inventory is less than a 7-day supply, but greater than a 6-day supply.
CCNPP RAI 2 Response:
In Reference 1, we intended to modify the Technical Specifications as shown on the attached marked up pages. The description of the change in Section 2.0 of Reference 1 was not clear in that it described Conditions A, B, and C as if they had the same requirements. The revised description is below and replaces the description in Reference 1.
Conditions A, B, and C in the Action are revised. Currently Conditions A, B, and C are entered when the stored diesel fuel oil numerical volume requirements are not met. As discussed in the current Technical Specification Bases, the numerical volume requirements of Condition A is based on volumes less than a 7-day supply, but greater than a 6-day supply. The numerical volume requirements of Conditions B and C are based on volumes less than a 7-day supply. Therefore, a Unit must enter Conditions B or C when the fuel oil inventory is less than a 7-day supply. The revision relocates the volumetric requirements from the Technical Specifications and places it in the Technical Specification Bases. The Technical Specification is modified so that Condition A is entered when the stored diesel fuel oil inventory is less than a 7-day supply, but greater than a 6-day supply for a diesel generator, and Conditions B or C are entered when the stored diesel fuel oil inventory is less than a 7-day supply.
NRC RAI 3:
While reviewing the standby emergency power configuration, the NRC staff noted that DGs 1B, 2A, and 2B all share a fuel oil supply from FOSTs 11 and 21. The TSs require Calvert Cliffs to store a minimum volume offuel oil in FOST 21 to allow for the continued operation of two DGs (one for each unit) for 7 days. According to the Calvert Cliffs Updated Final Safety Analysis Report (UFSAR), the standby power system design is such that the DGs automatically start and connect to their respective 4.16 kV buses in the event of an under voltage (UV) on those buses. In the event of a tornado onsite that destroys the switchyard and causes a loss of all offsite power, all three generatorswould automatically start and connect to their respective buses. Also stated in the Calvert Cliffs UFSAR, FOST 11 is not missile protected, and therefore, not credited in the event of a tornado. Consequently, in the event of a tornado that destroys the switchyard and FOST 11, at least one of the three DGs supplied by FOST 21 would have to be unloaded and shutdown to allow FOST 21 to fulfill its safety function (requiredvolume of stored fuel oil can support only 2 DGsfor 7 days).
The NRC staff requests that the licensee provide the following information:
3.1 When does the licensee shutdown at least one of the three DGs supplied by FOST 21 after an automatic UV startup of the DGs resultingfrom a tornado?
3.2 Provide information on the process or procedures used to remove a DGfrom service, including the time needed to complete the proceduralsteps.
3.3 Describe the time required and the process to start and realign the previously shutdown generatorgiven a single failure has occurred in the redundant load group.
2
ATTACHMENT (1)
RESPONSE TO REQUEST FOR ADDITIONAL INFORMATION REGARDING ADOPTION OF TSTF-501-A, REVISION 1, "RELOCATE STORED FUEL OIL AND LUBE OIL VOLUME VALUES TO LICENSEE CONTROL" CCNPP RAI 3 Response:
RAI 3.1: Number 21 FOST has a low level alarm set above the level for the Technical Specification limit (i.e., 85,000 gallons). The alarm manual for this alarm contains a Note reminding operators that No. 21 FOST contains sufficient fuel oil for seven days of operation with 2 DGs. It requires operators to consider ordering more fuel oil for No. 21 FOST. Additionally, the alarm manual contains a step that requires the operators to consider securing one of the running DGs if all three DGs are aligned to No. 21 FOST. A decision to shut down a running and loaded DG is complex and includes many factors such as the availability of fuel oil resupply and damage to on-site and off-site infrastructure.
If all three Fairbanks Morse DGs are aligned to No. 21 FOST and a tornado were to occur that resulted in a loss of offsite power and the No. 11 FOST, then the operators would have approximately 10 hours1.157407e-4 days <br />0.00278 hours <br />1.653439e-5 weeks <br />3.805e-6 months <br /> to secure a running DG from the time the low level alarm sounds before encroaching on the requirement to have 7 days of fuel oil for two DGs running at their continuous rating. If we consider the actual DG loading post tornado (assuming the worst electrical loading over the entire 7 day period), then the operators have 11.7 hours8.101852e-5 days <br />0.00194 hours <br />1.157407e-5 weeks <br />2.6635e-6 months <br /> to secure a running DG from the time the low level alann sounds.
RAI 3.2: The steps to execute a rapid shutdown of a running and loaded DG are straightforward. The steps involve placing the output breaker hand switch of the DG in "pull-to-lock," thereby separating the DG from the bus it is powering. This action can be performed from the Control Room. An operator is sent to the DG room to locally trip the DG fuel racks, which isolates fuel to the engine resulting in engine shutdown. We estimate no more than 30 minutes are needed to dispatch the operator and complete the shutdown of the DG.
RAI 3.3: The steps to restart a DG that has been shutdown in accordance with the steps outlined above are equally straightforward. The output breaker hand switch is returned to its "normal" position. This action is accomplished in the Control Room. The fuel racks that were tripped earlier would be reset in the DG room. Then a reset button is pushed in the DG room and the DG will automatically restart within 60 seconds and, assuming that a loss of offsite power still exists, the DG's output breaker will close to its associated 4 kV bus automatically. The shutdown sequencer will sequentially load the shutdown loads on the DG. These actions take only minutes to complete.
REFERENCE:
- 1. Letter from G. H. Gellrich (CCNPP) to Document Control Desk (NRC), dated October 2, 2012, Application for Technical Specification Improvement to Adopt TSTF-501-A, Revision 1, "Relocate Stored Fuel Oil Volume Values to Licensee Control" 3
ATTACHMENT (2)
TECHNICAL SPECIFICATION BASES PAGES B 3.8.1-26 AND B 3.8.1-34 Calvert Cliffs Nuclear Power Plant, LLC July 1, 2013
AC Sources-Operating B 3.8.1 BASES Although no power factor requirements are established by this SR, the DG is normally operated at a power factor between 0.8 lagging and 1.0. The 0.8 value is the design rating of the machine, while 1.0 is an operational limitation. The 31-day Frequency for this SR is consistent with Reference 3.
This SR is modified by four Notes. Note 1 indicates that the diesel engine runs for this surveillance test may include gradual loading, as recommended by the manufacturer, so that mechanical stress and wear on the diesel engine are minimized. Note 2 states that momentary transients because of changing bus loads do not invalidate this test. Note 3 indicates that this surveillance test shall be conducted on only one DG at a time in order to prevent routinely paralleling multiple DGs and to minimize the potential for effects from offsite circuit or grid perturbations. Note 4 stipulates a prerequisite requirement for performance of this SR. A successful DG start must precede this test to credit satisfactory performance.
i* oi *-* SR 3.8.1.5 SThis SR provides verification that the level of fuel oil in k&ovr Svpp- it the day tank is at or above the level at which fuel oil is
~ ~ciiors ~automatically added. The level required by the SR is Cr0. -27S se ec o ensure adequate fuel oi of go-x\oS cx s , one hour of DG operation at full load plus 10%.?
J Z,A a The 31-day Frequency is adequate to assure that a sufficient U'-' *_ wcwa~c_-'- k supply of fuel oil is available, since low level alarms are r tm cý occ, -L-k provided, and unit operators would be aware of any large Suses of fuel oil during this period.
-"-*-'* SR 3.8.1.6 Microbiological fouling is a major cause of fuel oil degradation. There are numerous bacteria that can grow in fuel oil and cause fouling, but all must have a water environment in order to survive. Removal of water from the fuel oil day tanks once every 31 days eliminates the necessary environment for bacterial survival. This is the most effective means of controlling microbiological fouling.
CALVERT CLIFFS - UNITS 1 & 2 B 3.8. 1-26 Revision 26
AC Sources-Operating B 3.8.1 BASES
- 11. NO-1-117, Integrated Risk Management 3.8.1-34 B 3.8. Revision 46 UNITS 1 CLIFFS - UNITS CALVERT CLIFFS & 2 1 & 2 B 1-34 Revision 46