L-PI-10-102, Prairie Lsland, Unit 1 - Response to NRC Request for Additional Information Received October 17, 2010 Related to Exigent License Amendment Request to Modify Technical Specifications Surveillance Requirement 3.8.1.10
| ML102930074 | |
| Person / Time | |
|---|---|
| Site: | Prairie Island  |
| Issue date: | 10/18/2010 |
| From: | Sawatzke B Northern States Power Co, Xcel Energy |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| L-PI-10-102 | |
| Download: ML102930074 (15) | |
Text
@ Xcel Energy*
L-PI-10-102 10 CFR 50.90 U.S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, DC 20555-0001 Prairie lsland Nuclear Generating Plant Unit 1 Docket 50-282 License No. DPR-42 Response to NRC Request for Additional lnformation received October 17, 2010 related to Exiaent License Amendment Request to Modify Technical Specifications Surveillance Requirement 3.8.1.10 for Prairie lsland Nuclear Generating Plant Unit 1
References:
- 1) Letter from Northern States Power Company, a Minnesota corporation, (NSPM) to the Nuclear Regulatory Commission (NRC),
"Exigent License Amendment Request to Modify Technical Specifications Surveillance Requirement 3.8.1.10 for Prairie lsland Nuclear Generating Plant Unit 1," L-PI-10-098, dated October 14, 2010.
- 2) Letter from NSPM to the NRC, "Response to NRC Request for Additional lnformation received October 15, 2010 related to Exigent License Amendment Request to Modify Technical Specifications Surveillance Requirement 3.8.1.10 for Prairie lsland Nuclear Generating Plant Unit 1," L-PI-10-100, dated October 16, 2010.
- 3) Letter from NSPM to the NRC, "Second Response to NRC Request for Additional lnformation received October 15, 2010 related to Exigent License Amendment Request to Modify Technical Specifications Surveillance Requirement 3.8.1.I 0 for Prairie lsland Nuclear Generating Plant Unit 1," L-PI-I0-101, dated October 17, 2010.
In Reference 1, NSPM, doing business as Xcel Energy, submitted a License Amendment Request (LAR) to request an exigent amendment to the Prairie lsland Nuclear Generating Plant (PINGP) Unit 1 Technical Specifications (TS) surveillance requirements (SR). The proposed TS change would allow emergency diesel generator (EDG) D2 to be operable until SR 3.8.1. I0 can be performed during the scheduled 1717 Wakonade Drive East Welch, Minnesota 55089-9642 Telephone: 651.388.1121
Document Control Desk Page 2 j Unit 1 2011 refueling outage. Reference 1 also identified 12 Battery Charger performance issues that should be corrected prior to performance of SR 3.8.1 .I 0 for 02.
On October If, 2010 the NRC transmitted to NSPM draft follow-on requests for additional information (RAI), Enclosure 1 provides responses to these RAls.
The supplemental information provided in this letter does not impact the conclusions of the Determination of No Significant Hazards Consideration or Environmental Assessment presented in the Reference 1 submittal as supplemented in References 2 and 3.
In accordance with 10 CFR 50.91, NSPM is notifying the State of Minnesota of this LAR supplement by transmitting a copy of this letter to the designated State Official.
If there are any questions or if additional information is needed, please contact Jon Anderson at 651-388-1121 x7309.
Summary of Commitments This letter contains no new commitments. The commitment in Reference 1 is withdrawn due to proposed TS revisions provided in Enclosure 1 to this letter.
I declare under penalty of perjury that the foregoing is true and correct.
Executed on /&&I
~ r a d l d yJ. Sawatzke
~irector,Site Operations, Prairie Island Nuclear Generating Plant Northern States Power Company - Minnesota Enclosures (I) cc: Administrator, Region Ill, USNRC Project Manager, PINGP, USNRC Resident Inspector, PINGP, USNRC State of Minnesota
Technical S~ecificationsSurveillance Requirement 3.8.1.10 for This enclosure includes responses from the Northern States Power Company, a Minnesota corporation (NSPM), to Requests for Additional Information (RAI) regarding exigent license amendment request (LAR) to modify Technical Specifications (TS)
Surveillance Requirement (SR) 3.8.1.10 for Prairie Island Nuclear Generating Plant (PINGP) Unit 1.
These RAls are associated with NSPM's request to modify SR 3.8.1 . I 0 to add a note that allows emergency diesel generator (EDG) D2 to be operable without energizing the 12 Battery Charger during safety injection (SI) testing until the Unit 1 2011 refueling outage. Also, NSPM has identified modifications to be completed on the 12 Battery Charger prior to performance of SR 3.8.1 . I 0 for 02.
This supplement provides responses to the RAls the NRC provided on October 17, 2010.
This Enclosure quotes each RAI question in italics and each question is followed by the NSPM response. Referenced documents are identified at the end of this Enclosure.
NRC IHPB-1 follow-on question 1:
If the Portable Charger is moved from the 12 Battery Room to replace another Safeguards Battery Charger, is there any limit to the amount of time the Portable Battery Charger may remain in that configuration?
NSPM Response There is no TS or procedural requirement limiting the time that the Portable Battery Charger can stay in service in place of an inoperable Safeguard Battery Charger.
NRC IHPB-1 follow-on question 2:
How long would it take to move the Portable Charger back into the 12 Battery Room if needed?
Enclosure NSPM Response To NRC RAls I
NSPM Response Approximately one hour is required to move the Portable Battery Charger from being installed in one battery room to being installed, hooked up and placed in service in a different battery room.
NRC IHPB-2 follow-on question I:
NRC uses the term "dedicated" operator only when operator is located in the immediate vicinity of where the task needs to be performed and is capable of performing the task on demand, requiring no decision time, preparation time, or travel time. Please revise your description or use another term, such as "assigned operator" or 'Uesignated operator" so that there is no confusion.
NSPM Response NSPM has a designated Battery Charger Watch person to attend to the battery chargers. Any reference to "dedicated" operator in the LAR or RAls should be replaced with "designated" operator.
NRC IHPB-2 follow-on question 2:
Does PINGP use three-way communication; i.e. sender and receiver repeat-backs?
NSPM Response Yes. At PINGP, personnel are required to utilize three way communications for any operationally significant communications. Any orders to the designated Battery Charger Watch would be considered operationally significant.
NRC IHPB-2 follow-on question 3:
NSPM has stated that the pager system will be used to communicate with the dedicated operator. Verify that the pager system or other radio communications will be powered and available under all scenarios where compensatory actions could be necessary?
NSPM Response The plant pager (beeper system) is powered from PNL 3146 which has a normal (PNL 3144) and emergency (PNL 3134) power supply. Panels 3144 and 3134 are powered by non-safeguards inverters (34 and 33 inverters) and both inverters are backed up by non-safety related diesel generators (D4 and D3).
Page 2 of 11
Enclosure NSPM Response To NRC RAls The phones are powered from Safeguards Panel 217, Panel 217 is powered from Bus 25 via Bus 211 and will be the primary source of communications to the designated Battery Watch.
The plant page (loudspeaker system) is the back-up mode for communication with the designated Battery Watch which is powered by Panel 116 which is powered from Panel 3134 via non-safeguards inverter 33 which is backed up by a non-safeguards diesel (D3).
NRC IHPB-2 follow-on question 4:
Are there any scenarios where the 72 Battery Room will be difficult to access, for example, because of radiation or high temperature? If so, plans should be made to verifL the compensatory actions under these conditions (dress-out, ice pack suits, etc.).
NSPM Response Yes, it is possible that a High Energy Line Break (HELB) or flooding could occur in the Turbine Building of the Safety Injection (SI) unit. NSPM has designated where the Battery Watch can be stationed and all entry points for travel to the required battery room by traveling through the non-SI unit to the affected battery room. These travel paths have been time verified to ensure all battery chargers will be started in the time required.
NRC IHPB-2 follow-on question 5:
Will controlled procedures be immediately available to the designated operator, e.g. pre-staged in the Battery Room or handed out at the shift-change briefing?
NSPM Response Yes, there are controlled copies of the applicable abnormal operating procedure posted on station in each battery room.
NRC IHPB-2 follow-on question 6:
To whom will the designated operator report?
NSPM Response The designated Battery Watch will report to the Unit 1 and Unit 2 Shift Supervisor (SS) and answer the SS on the affected unit if Battery Watch person's services are required.
Page 3 of 11
Enclosure NSPM Response To NRC RAls SROs and ROs may not be familiar with the actions required to re-start the battery chargers. Is there a Job Performance Measurn that will be used to refresh the designated operators?
NSPM Response There are no plans to implement additional training beyond the Licensed Operator Requalification program. The available pool of watchstanders has documented a walk through of the Abnormal Operating procedures on location at each battery room.
NRC EEEB follow-on question 1 (EEEB-3):
- 1. In letter dated October 16, 2010, the licensee has stated that "The proposed change would allow the 12 Battery Charger to not be energized during the Safety Injection testing until a modification is completed during the Unit I 201 1 refueling outage.
Prior to start up from the 201 I refueling outage, the 12 Battery Charger will be tested in accordance with TS SR 3.8.1.1O(c)." This statement and the proposed note added to TS SR 3.8. I . lO(c) imply that the operability EDG 0 2 can be established without the associated charger load. In addition, it can be further implied that the operability of the associated charger, when EDG 0 2 is supplying safety loads, does not have to be established by loading it on EDG 02. In response to staff RAI #
EEEB-3, NSPM has stated that the proposed note is acceptable as the next scheduled surveillance for EDG 0 2 is planned during the upcoming refueling outage and the modification will be implemented.
The staff is proposing the following license condition in lieu of modifying the note TS SR 3.8.I . IO(c), or the licensee is requested to modify the existing TS to address the following:
"NSPM will implement a modification as soon as practical that will automatically shed the safety related Battery Chargers from their normal busses and then automatically reconnect the chargers to their respective bus within the 60 seconds required by the Prairie Island Nuclear Generating Plant Technical Specifications (TS) surveillance requirement (SR) 3.8.1.1O(c). NSPM will perform the surveillance test during the forced outage of Unit I or during 201 1 Spring refueling outage, whichever comes first. Compliance with TS SR 3.8. I.10 will be demonstrated after implementation of the modification."
NSPM Response NSPM proposes to revise TS page 3.8.1-10 as provided in the Attachment 1 to this Enclosure. The revised proposed TS includes a footnote that requires NSPM to modify Page 4 of 11
Enclosure NSPM Response To NRC RAls the 12 Battery Charger and perform SR 3.8.'l.4 0 after the modification is complete. This proposed footnote captures the essence of the commitment made in the Reference 1, and therefore NSPM withdraws the commitment.
The footnote differs from the commitment in that the clause "or prior to" has been included in the footnote so commencement of installation activities prior to the outage is not prevented.
In response to NRC RAI EEEB-3 in Reference 2, NSPM proposed to include discussion of compensatory measures in the TS 3.8.1 Bases. Pursuant to addition of the proposed footnote to SR 3.8.1 .lo, NSPM does not intend to make any changes to the Bases.
NRC EEEB follow-on question 2 (EEEB-1):
The licensee, in its letter dated October 16, 2010 (in the response to Question EEEB-I),
stated that the dropout voltage for the contactors or interposing relays is between 140 VAC and 315 VAC or between 200 VAC and 360 VAC, depending on the size of contactor. This criteria was used to establish operability of low voltage components during voltage perturbations. The staff has following related questions:
a) Clarify the nominal system voltages associated with the acceptance criteria for the contactors discussed above. What are the vendor-recommended dropout and pickup voltages for contactors? If the voltages are below the vendor recommendations, provide the basis for why the voltage established by the periodic surveillance tests is adequate to demonstrate its capability to operate during a worst case design basis event.
b) Clarify the significance of the voltage range in acceptance criteria for the size of contactors considered.
c) Provide the earliest dates for surveillance tests performed on the contactors that were evaluated.
d) Provide clarification on the effects of voltage perturbations on operating equipment during worst case EDG load sequencing. Verify that the voltage deviations during EDG load sequencing do not drop below the acceptance criteria for the loads evaluated.
Page 5 of 11
Enclosure NSPM Response To NRC RAls NSPM Response Clarification to Question 2:
The above question states the following: "This criteria was used to establish operability of low voltage components during voltage pertu&ations." This statement was not made in the letter dated October 16, 2010 (in the response to Question EEEB-I).
Question 2a:
Nominal system voltage at the motor control center (MCC) level is 480 VAC. MCC control circuits contain a 4801120 V control circuit transformer to provide nominal 120 VAC control voltage.
PlNGP went into commercial operation in 1973. Vendor technical information reviewed for MCC control circuit components found that dropout voltage requirements were not specified. The maximum dropout voltage for the MCC contactors and interposing relays required in preventative maintenance procedures is established below the maximum expected voltage dip during sequence loading based on current analysis and testing.
The upper limit for drop-out voltage of 315 VAC for safety related MCC contactors is used in the MCC electrical preventative maintenance procedure.
The maximum pickup voltage of contactors required in preventative maintenance procedures was evaluated in response to NRC Generic Letter (GL) of August 8, 1979, "Adequacy of Station Electric Distribution System Voltages." The response to the Generic Letter was evaluated in NRC Safety Evaluation contained in a letter from the NRC to NSPM dated October 29, 1982.
Current degraded voltage analysis using the 4kV analytical limit of 94.5% of 4160V, shows that MCC voltages remain above 87.2% of 480V (418.6V) under steady state conditions. The MCC control circuit voltage drop calculation shows that at the minimum MCC voltage under degraded voltage conditions, the voltage at the contactor when considering voltage drop due to contactor in-rush conditions, is above the maximum pickup value tested by the preventative maintenance procedures. The maximum pickup voltage of the contactors required by preventative maintenance procedures ensures that the results of the calculation remain valid.
Question 2b:
The response to EEEB-1 in Reference 2 stated that the dropout range for the contactors were 140 VAC to 315 VAC. Dropout for interposing relays was either 140 VAC to 315 VAC or 200 VAC to 360 VAC.
The dropout range of 140 VAC to 315 VAC applies to all contactors within the preventative maintenance procedures.
The 140 VAC to 315 VAC dropout for interposing relays is the criteria in preventative maintenance procedures applied to relays installed in control circuits for size 3 and size Page 6 of 11
Enclosure NSPM Response To NRC RAls 4 starters. The 200 VAC to 366 VAC dropout for interposing relays is the criteria in preventative maintenance prowdures applied to relays installed in control circuits for GE Type 7700 MCCs size 1 and 2 starters. Preventative maintenance procedures for GE Type 8000 MCCs specify the dropout of interposing relays for size Ithrough size 4 starters to be 140 VAC to 315 VAC. Preventative maintenance procedures for Westinghouse 5 Star MCCs specify the dropout of interposing relays for size 3 and 4 starters to be 140 VAC to 315 VAC, An issue has been identified and documented in NSPMs Corrective Action Process (CAP) to identify this discrepancy in interposing relay dropout ranges for the size 1 and size 2 GE Type 7700 MCC starters. This preventative maintenance procedure is for both safety related and non-safety related starters. It has been verified that there are no safety related size 1 and size 2 starters in which an interposing relay is installed in the contactor control circuit. Therefore, the dropout range that applies to safety related interposing relays is 140 VAC to 315 VAC.
Question 2c:
The four contactors that were referenced in response to Question EEEB-1 in Reference 2 have the following preventative maintenance history.
Breaker Il2K-35 Last performed maintenance: 101312000 Breaker 122K-35 Last performed maintenance: 1011112000 Breaker 22 1K-I 0 Last performed maintenance: 411711996 Breaker 222K-35 Last performed maintenance: 712912010 Question 2d:
As stated above in response to Question 2b, the maximum dropout criteria for contactors or interposing relays is 65.6% of 480 VAC (315 VAC).
The acceptance criteria contained in the surveillance procedures for the initial sequence step shows that the minimum allowed EDG voltage is 2580 VAC (62% of 4160) for EDGs D l and D2, and 3120 VAC (75% of 4160) for EDGs D5 and D6. Since this is the initial sequence step, contactor drop out occurs during the load shedding of the MCC as part of the voltage restoration scheme and would not pick up until voltage recovery occurs in the initial step.
Performance of past surveillance tests indicate that the worst case voltage dip for the subsequent sequence steps remained above 80% voltage at the 4kV bus for EDGs D l and D2, and above 85% for EDGs D5 and D6.
Page 7 of 1I
Enclosure NSPM Response To NRC RAls Analysis for a safety injection (SI) signal initiated while on offsite power shows that the worst case voltage drop between the 4kV bus and the 480V MCC during any of the sequence steps was 15.7% for Unit 2 and 12.3% for Unit I.These values would be similar to the voltage drop that would occur between the 4kV bus and the MCCs during the EDG load sequencing. Using these values, the MCC voltages on EDGs D l and D2 would remain above 67.7% (80% - 12.3%) and the MCC voltages on EDGs D5 and D6 would remain above 69.3% (80% - 15.7%). These values are higher than the highest contactor dropout voltage of 65.6% with a margin of 2.1% for EDGs D l and 02 and 3.7% for EDGs D5 and D6.
The condition experienced by the 12 Battery Charger during the performance of the integrated SI test on D2, has not been identified on any other components during the performance of the integrated SI test for any of the EDGs (Dl, D2, D5, and D6).
NSPM does not currently have a dynamic model or dynamic analysis of the PlNGP EDGs to accurately predict downstream voltages during EDG load sequencing. The lack of these analyses is documented in a CAP that will track resolution of this issue (see table of CAPS below).
NRC EEEB follow-on question 3 (EEEB-I):
The licensee, in its letter dated October 16, 2010 (in the response to Question EEEB-I),
stated that, under degraded voltage conditions, the voltage drop in the control circuit will ensure adequate voltage to pickup the contactor.
The NRC staff notes that minimum steady state voltage of each EDG in the Technical Specifications (TS) SR 3.8.1.2 is stated as 3740 V. This value is lower than the minimum allowable voltage of 3944 V degraded voltage relay setting in SR 3.3.4.3.
Clarify what value of degraded voltage at 4160 V safety-related buses (connected to the EDGs) was used to evaluate dropouVpickup voltage of downstream contactors. Also, why was the minimum steady state voltage of the EDGs, as specified in TS, was not considered in your evaluation?
NSPM Response The value of degraded voltage at 4160 V safety-related buses used to evaluate the voltage of downstream contactors is 94.5% of 4160V or 3931.2V. This value is the degraded voltage analytical limit at the 4160V buses as evaluated in NSPM1sinternal calculation. This value of 94.5% of 4160V bounds the T.S. SR 3.3.4.3 value of 3944V.
NSPM previously recognized the discrepancies between the minimum allowable voltages identified in TS SR 3.8.1.2 of 3740V and TS SR 3.3.4.3 of 3944 V. This discrepancy was documented in a CAP and an administrative limit of 3944 V was Page 8 of 11
Enclosure NSPM Response To NRC RAls imposed in surveillance procedures that identified the 3740V value. As a result, the 3740 V was not considered in the NSPM evaluations.
This issue has also been identified as an industry wide issue and is the subject of a Pressurized Water Reactor Owners Group program of which the results will be presented to the NRC for review and approval. The final result of this program is not known at this time, but clarification will likely be provided that the TS value of 3740V is a transient value and the EDG is not expected to operate at this voltage for a significant period of time.
NRC EEEB follow-on question 4 (EEEB-1):
The licensee, in its lefter dated October 76, 2070 (in the response to Question EEEB-7),
stated that four contactors were further evaluated by an engineering evaluation using revised degraded voltage values at the MCC and pickup voltages required for the specific contactors.
Provide the value and basis for using the revised degraded voltage. Clarify whether this is the allowable value specified in the existing TS.
NSPM Response The calculation that evaluates MCC control circuit voltage drop was issued in 2000 and used the degraded voltage analysis in place at the time as the input for MCC voltages under degraded voltage conditions.
The degraded voltage analysis has been revised and a new calculation was issued in 2009. The electrical model used to develop the 2009 degraded voltage analysis has been improved from the model used to develop the 2000 analysis and includes more detail. The 2009 analysis is a more accurate representation system. Current actions are in progress to incorporate the 2009 degraded voltage analysis into the MCC control circuit voltage drop calculation.
The value of degraded voltage at 4160V safety-related buses used in the degraded voltage analysis is the degraded voltage analytical limit at the 4160V buses of 94.5% of 4160V or 3931.2V. This value of 94.5% of 4160V bounds the T.S. SR 3.3.4.3 value of 3944v.
NRC EEEB follow-on question 5 (EEEB-1):
The licensee, in its letter dated October 76, 2010 (in the response to Question EEEB-I),
stated that the engineering evaluation identified that one of the four breakers
[contactors] continued to show that the required pickup voltage under degraded voltage conditions could not be satisfied by testing. This was identified and evaluated under a Page 9 of 11
Enclosure NSPM Response To NRC RAls
[correction action plan] CAP and an operability recommendation (OPR) and appropriate compensatory measures were put in place to ensure that the ambient temperaturn at the identified MCC remained low enough to ensure adequate voltage would be present to pickup the MCC contactor.
Provide a summary of your corrective actions, including the operability determination and compensatory measures put in place. Also, provide details on actions taken if the ventilation system associated with this circuit is declared inoperable, NSPM Response The operability recommendation (OPR) concluded that when the ambient temperature for the MCC in question is below 114.62 degrees (deg) Fahrenheit (F), no compensatory measures are required to maintain breaker operability. However, if the ambient temperature at the MCC location exceeds 114.62 deg F, compensatory measures will be required to reduce the ambient temperature to less than this limit.
The corrective actions and compensatory measures to identify and correct the condition include the following:
An operator information (01) was issued to log the ambient temperature at the MCC location once every 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> during summer operations. It is not anticipated that the ambient temperature at the MCC location will reach 114.62 deg F during winter operations.
Procedure changes were expedited to provide an administrative limit of 114.62 deg F for the upper ambient temperature experienced at the MCC in question.
An Engineering Change (EC) was initiated to provide temporary cooling in the event that the ambient temperature exceeds 114.62 deg F for the MCC in question.
An Operable but Non-Conforming (OBN) action was initiated to provide the long term solution.
A temperature limit of 122 deg F is established in the vicinity of the MCCs for the Auxiliary Building Normal Ventilation System. As stated above, an administrative temperature limit of 114.62 deg F for the MCC in question has been incorporated into the operations procedures. Therefore, when the ambient temperature approaches this limit (with or without ventilation), the procedure directs operations to consult with Engineering to determine appropriate actions. These actions could either be to declare the affected equipment inoperable and take appropriate actions per Technical Specifications, reanalysis to justify a higher temperature limit, implement compensatory action or some other action.
List of CAPS related to this LAR In discussions with the NRC, NSPM identified that responses to RAls have identified some issues that will not be resolved in time to support approval of this LAR. Pursuant Page 10 of 11
Enclosure NSPM Response To NRC RAls to those discussions, NSPM agreed to provide the list of CAPS and their description to document the process for resolution of these issues.
References
- 1) Letter from Northern States Power Company, a Minnesota corporation, (NSPM) to the Nuclear Regulatory Commission (NRC), "Exigent License Amendment Request to Modify Technical Specifications Surveillance Requirement 3.8.1.I0 for Prairie lsland Nuclear Generating Plant Unit 1," L-PI-10-098, dated October 14, 2010.
- 2) Letter from NSPM to the NRC, "Response to NRC Request for Additional lnformation received October 15, 2010 related to Exigent License Amendment Request to Modify Technical Specifications Surveillance Requirement 3.8.1 .I0 for Prairie Island Nuclear Generating Plant Unit I," L-PI-10-100, dated October 16, 2010.
- 3) Letter from NSPM to the NRC, "Second Response to NRC Request for Additional lnformation received October 15, 2010 related to Exigent License Amendment Request to Modify Technical Specifications Surveillance Requirement 3.8.1.10 for Prairie Island Nuclear Generating Plant Unit 1," L-PI-10-101, dated October 17, 2010.
Page I 1 of 11
ENCLOSURE 1, ATTACHMENT 1 Technical Specification Pages (Markup) 3.8.1-10 Ipage follows
AC Sources-Operating 3.8.1 SURVEILLANCE SR 3,8,1,10 ............................ NOTES---.. ----------..------....----
- 1. All DG starts may be preceded by an engine prelube period.
2.- This Surveillance shall not be performed in MODE 1,2,3, or 4.
- 3. -C
~~~,er&".zc"d.
-. - in.
wf Unit 1 201 1 refueling
" " - outage.*
Verify on an actual or simulated loss of offsite power 24 months signal in conjunction with an actual or simulated safety injection actuation signal:
- a. De-energization of emergency buses;
- b. Load shedding from emergency buses; and
- c. DG auto-starts from standby condition and energizes emergency loads in < 60 seconds.
SR 3.8.1.11 ............................ NOTE--------- ----------- --------
All DG starts may be preceded by an engine prelube period.
VeriQ on an actual or simulated loss of offsite power 24 months signal that the DG auto-starts from standby condition.
- A n~odificgtion-willbc installcd during or prior to the Unit-1 20 11 rcfEling outig_eto at~tomatically shed the 12 Battery charger fiom its nomal bus and then renovver the charger from the bus within 60 seconds. Compfia~zcewith this SR xvill be demonstrated after implen~enlationoft&
modificatip-n.
Prairie Island Unit 1 - Amendment No. 44-8 Units 1 and 2 3.8.1-10 Unit 2 - Amendment No. 149