GNRO-2008/00013, License Amendment Request, Technical Specification Surveillance Requirements for Diesel Generator Slow Start Testing

License Amendment Request, Technical Specification Surveillance Requirements for Diesel Generator Slow Start Testing

ML082560136
Person / Time
Site:	Grand Gulf
Issue date:	09/11/2008
From:	Krupa M Entergy Operations
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
GNRO-2008/00013
Download: ML082560136 (20)

Text

GNRO-2008/00013 September 11, 2008 U. S. Nuclear Regulatory Commission Attention: Document Control Desk Washington, D. C. 20555

SUBJECT:

License Amendment Request Technical Specification Surveillance Requirements for Diesel Generator Slow Start Testing Grand Gulf Nuclear Station Unit 1 Docket No. 50-416 License No. NPF-29

Dear Sir or Madam:

Pursuant to 10CFR50.90, Entergy Operations, Inc. (Entergy) hereby requests the following amendment to the Grand Gulf Nuclear Station Unit 1 (GGNS) Operating License pursuant to 10 CFR 50.91 (a)(6).

The proposed change will affect Surveillance Requirements for Technical Specification (TS) Limiting Condition for Operation (LCO) 3.8.1 and 3.8.2 and is based on NUREG 1434, "Standard Technical Specifications General Electric Plants, BWR/6" and Generic Letter 84-15, "Proposed Staff Actions to Improve and Maintain Diesel Generator Reliability." The proposed change provides for the implementation of a slow-start testing sequence for the standby Diesel Generators (DGs) on a monthly frequency in order to reduce stress and wear on the equipment. The DGs will continue to receive a fast-start test on a 184 day frequency. The NRC has previously approved similar Technical Specification Amendments for other nuclear power plants, including River Bend Unit 1 and Hope Creek Unit 1.

The proposed change has been evaluated in accordance with 10CFR 50.91 (a)(1) using criteria in 10 CFR 50.92(c) and it has been determined that this change involves no significant hazards considerations. The bases for these determinations are included in the attached submittal.

There are no commitments associated with this license amendment request.

GNRO-2008/00013 Page 2 Although this request is neither exigent nor emergent, your prompt review is requested upon receipt since the change is seen as an improvement in the long-term reliability of the Diesel Generators. Plant modifications necessary to accomplish the slow-starting sequence for the Division 1 and 2 Diesel Generators are planned to be completed during the next scheduled refueling outage during (RF16) which is scheduled to start in September of 2008. Once approved, the amendment shall be implemented post outage and after approval.

If you have any questions or require additional information, please contact Michael Larson at 601-437-6685.

I declare under penalty of perjury that the foregoing is true and correct. Executed on September 11, 2008 Sincerely, MAKlMJL/amm Attachments: 1. Analysis of Proposed Technical Specification Change

2. Proposed Technical Specification Changes (mark-up)

3. Proposed Technical Specification Bases (mark-up)

CC: Mr. Elmo Collins Regional Administrator, Region IV U.S. Nuclear Regulatory Commission 611 Ryan Plaza Drive, Suite 400 Arlington, TX 76011-4005 U.S. Nuclear Regulatory Commission ATTN: Mr. Jack N. Donohew, Jr., NRR/APRO/DORL (w/2)

ATTN: ADDRESSEE ONLY ATIN: U.S. Postal Delivery Address Only Mail Stop OWFN/O-8G 14 Washington, D.C. 20555-0001 Dr. Ed Thompson, MD, MPH Mississippi Department of Health P. O. Box 1700 Jackson, MS 39215-1700 NRC Senior Resident Inspector Grand Gulf Nuclear Station Port Gibson, MS 39150

Attachment 1 GNRO-2008/00013 Analysis of Proposed Technical Specification Change to GNRO-2008/00013 Page 1 of 4

1.0 DESCRIPTION

This letter is a request to amend Operating License NPF-29 for Grand Gulf Nuclear Station, Unit 1 (GGNS).

2.0 PROPOSED CHANGE

The proposed change will revise Technical Specification (TS) Surveillance Requirements (SR) for Limiting Condition for Operation (LCO) 3.8.1 and 3.8.2 and add a new SR to TS LCO 3.8.1 to require monthly Diesel Generator (DG) testing by idling and gradually accelerating each DG to operating speed. The actual time to reach stable conditions will be determined in post-modification testing. The purpose of the change to a monthly slow start test mode is to reduce stress and wear on the equipment. The proposed changes are as follows:

1. SR 3.8.1.2 would be revised to eliminate the start time requirements. Additionally, two Notes would be added to the revised SR 3.8.1.2. Note 1 will indicate that performance of the new SR 3.8.1.21 (which will be identical to the original SR 3.8.1.2 with the exception of a 184 day Frequency and which is more restrictive than revised SR 3.8.1.2) would satisfy the requirements of the revised SR 3.8.1.2. The second, added as Note 3, will clarify that if modified procedures, which result in gradual acceleration to synchronous speed are not used, then the start time requirements of the new SR 3.8.1.21 would apply.

2. Change to SR 3.8.1.3 is an editorial change to reflect the addition of the new SR 3.8.1.21, i.e., that SR 3.8.1.2 or SR 3.8.1.21 may be used to start the DG for the purposes of performing SR 3.8.1.3.

3. New SR 3.8.1.21 is being added. New SR 3.8.1.21 is identical to original SR 3.8.1.2 with the exception of the new Frequency of 184 days.

4. Editorial changes to SR 3.8.2.1 are being made to reflect the addition of the new SR 3.8.1.21.

The TS surveillances which require verification of a fast start on an 18 month frequency are not affected by the proposed changes. In addition, a new surveillance is added to test the fast start on a 184 day frequency. Therefore, the ability of the DGs to achieve the start times assumed in the accident analyses will continue to be periodically verified.

3.0 BACKGROUND

At GGNS, the existing Division 1 and 2 DG governors are being replaced with a model that will accelerate the engines to operating speed within a range of approximately 15 to 40 seconds in the test mode. This is considered a slow start for these DGs which are designed to start in less than 10 seconds and typically start in less than 8 seconds. The Technical Specification Surveillance Requirements and accompanying Notes indicate that the fast start shall be utilized if slow start procedures are not employed.

At this time, there are no specific plans for making changes to the operation of Division 3 HPCS (High Pressure Core Spray) DG which is manufactured by a different vendor than Division 1 and 2 DGs. However, this licensing amendment has been developed to accommodate slow starting of all three DGs if the slow start capability is available. The Technical Specification Surveillance Requirements and accompanying Notes indicate that the fast start shall be utilized if slow start procedures are not employed.

to GNRO 2008-00013 Page 2 of 4

4.0 TECHNICAL ANALYSIS

As stated above, the Division 1 and Division 2 DG governors are being replaced with a model that has design provisions to allow the engines to be slowly accelerated to operating speed within a range of approximately 15 to 40 seconds in the test mode. When the DGs are in standby for emergency operation, they will continue to fast start in accordance with their emergency function. This is consistent with the NUREG 1434, "Standard Technical Specifications'General Electric Plants, BWR/6" and Regulatory Guide (RG) 1.9, Revision 3.

Paragraph 2.2.1, "Start Test", of RG 1.9, Revision 3, states that for these tests the emergency diesel generator can be slow started and reach rated speed on a prescribed schedule that is selected to minimize stress and wear. GGNS complies with Revisions 2 and 3 of RG 1.9 as detailed in GGNS UFSAR 8.3.1.2.1 "Compliance".

NRC sponsored aging research work on nuclear service diesel generators, documented in NUREG/CR-5057, "Aging Mitigation and Improved Programs for Nuclear Service Diesel Generators," has identified fast starting and fast loading tests of DGs as an aging stressor.

Section 2.4.1 of this report states that a correctly managed monthly testing program involving slow starting and loading would induce little aging effects in the emergency DG. By contrast, a fast starting and loading test program can produce substantial harm and significant aging effects through the production of large mechanical and thermal stresses, inadequate lubrication during initial acceleration, high rotating and sliding pressures, and overspeeding. The slow start is also consistent with recommendations of ASME/ANSI Operations and Maintenance Standards and Guides Part 16. (Note that NUREG-1366 states a concern that this feature may be incorporated at the cost of reducing DG reliability by eliminating a redundant overspeed protection in the form of the backup mechanical governor. At GGNS, the backup mechanical governor will remain in service during the slow start.)

The governors for the Division 1 and 2 DGs are scheduled to be replaced during the Fall 2008 refueling outage (RF16) scheduled to begin in September 2008. Routine monthly testing on the DGs will consist of fast starts until such time as the governors are replaced and the License Amendment is issued.

5.0 REGULATORY ANALYSIS

5.1 Applicable Regulatory Requirements/Criteria The proposed change has been evaluated to determine whether applicable regulations and requirements continue to be met. The change will maintain compliance with 10 CFR 50 Appendix A, General Design Criteria (GDC) 17 and 18. Entergy has determined that the proposed change does not require any exemptions or relief from regulatory requirements, other than the TS, and does not affect conformance with any GDC described in the Updated Final Safety Analysis Report (UFSAR).

to GNRO 2008-00013 Page 3 of 4 5.2 No Significant Hazards Considerations Entergy has evaluated whether or not a significant hazards consideration is involved with the proposed amendment by focusing on the three standards set forth in 10 CFR 50.92, "Issuance of Amendment", as discussed below:

1. Does the proposed change involve a significant increase in the probability or consequences of an accident previously evaluated?

Response: No.

The proposed change affects the surveillance requirements for the Diesel Generators (DGs). The DGs are onsite standby power sources intended to provide redundant and reliable power to ESF systems credited as accident mitigating features in design basis analyses. Per NRC Regulatory Guide (RG) 1.9, Revision 3, which is referenced in Grand Gulf Nuclear Station (GGNS) UFSAR 8.3.1.2.1, the proposed change is intended to allow slower starts of the DGs during testing in order to reduce DG aging effects due to excessive testing conditions. As such, the proposed change will result in improved DG reliability and availability, thereby providing additional assurance that the DGs will be capable of performing their safety function. The method of starting the emergency diesel generators for testing purposes does not affect the probability of any previously evaluated accident. Although the change allows slower starts for the monthly tests, the more rapid start function, assumed in the accident analysis, is unchanged and will be verified on a 184 day frequency. Therefore the accident analysis consequences are not affected.

Therefore, the proposed change does not involve a significant increase in the probability of consequences of any accident previously evaluated.

2. Does the proposed change create the possibility of a new or different kind of accident from any accident previously evaluated?

Response: No.

The proposed change affects the surveillance requirements for the onsite ac sources, i.e. the Diesel Generators. Accordingly, the proposed change does not involve any change to the configuration or method of operation of any plant equipment that could cause an accident. In addition, no new failure modes have been created nor has any new limiting failure been introduced as a result of the proposed surveillance changes.

Therefore, the proposed change does not create the possibility of a new or different kind of accident from any previously evaluated.

to GNRO 2008-00013 Page 4 of 4

3. Will operation of the facility in accordance with this proposed change involve a significant reduction in a margin of safety?

Response: No.

The proposed change is intended to bring the existing GGNS TS requirements for the onsite AC sources in line with regulatory guidance. Under the proposed change, the DGs will remain cap'able of performing their safety function, and the effects of aging on the DGs will be reduced by eliminating unnecessary testing. The DG start times assumed in the current accident analyses are unchanged and will be verified on a 184 day frequency.

Therefore, the proposed change does not involve a significant reduction in the margin of safety.

Based on the above, Entergy concludes that the proposed amendment presents no significant hazards consideration under the standards set forth in 10 CFR 50.92(c), and, accordingly, a finding of "no significant hazards consideration" is justified.

5.3 Environmental Considerations The proposed amendment does not involve (i) a significant hazards consideration, (ii) a significant change in the types or significant increase in the amounts of any effluent that may be released offsite, or (iii) a significant increase in individual or cumulative occupational radiation exposure. Accordingly, the proposed amendment meets the eligibility criterion for categorical exclusion set forth in 10 CFR 51.22(c)(9). Therefore, pursuant to 10 CFR 51.22 (b), no environmental impact statement or environmental assessment needs to be prepared in connection with the proposed amendment.

6.0 PRECEDENCE There is precedence for requesting the proposed amendment to allow slow start testing of the emergency Diesel Generators. Refer to the approved amendment packages provided below.

The proposed change is consistent with NUREG 1434, "Standard Technical Specifications General Electric Plants, BWR/6" and Generic Letter 84-15, "Proposed Staff Actions to Improve and Maintain Diesel Generator Reliability." The proposed amendment is based on Regulatory Guide 1.9, Revision 3, "Selection, Design, Qualification, And Testing Of Emergency Diesel Generating Units Used As Class 1E Onsite Electric Power Systems At Nuclear Power Plants".

7.0 REFERENCES

1. River Bend Station, Unit 1, Issuance of Amendment No. 121 to Facility Operating License No. NPF-47 by USNRC in letter to Randall K. Edington dated September 27, 2001 (TAC No. MB1117).

2. Hope Creek Generating Station, Unit 1, Issuance of Amendment No. 144 to Facility Operating License No. NPF-57 by USNRC in letter to Harold W. Keiser dated March 17, 2003 (TAC No. MB6084).

Attachment 2 GNRO*2008/00013 Proposed Technical Specification Change (mark-up)

Attachment 2 to GNRO 2008-00013 Page 1 017 (b) SERl is required to notify the NRC in writing prior to any change in (i) the terms or conditions of any new or existing sale or lease agreements executed as part of the above authorized financial transactions, (ii) the GGNS Unit 1 operating agreement, (iii) the existing property insurance coverage for GGNS Unit 1 that would materially alter the representations and conditions set forth in the Staff's Safety Evaluation Report dated December 19 1988 attached to Amendment No. 54.

1 In addition, SERI is required to notify the NRC of any action by a lessor or other successor in interest to SERl that may have an effect on the operation of the facility.

C. The license shall be deemed to contain and is subject to the conditions specified in the Commission's regulations set forth in 10CFR Chapter I and is subject to all applicable provisions of the Act and to the ruies l regulations, and orders of the Commission now or hereafter in effect; and is subject to the additional conditions specified or incorporated below:

(l) Maximum Power Level Entergy Operations Inc. is authorized to operate l

the facility at reactor cor.e power levels not in excess of 3898 megawatts thermal (100 percent power) in accordance with the conditions specified herein.

Insert New (2) Technical Specifications Amendment No.

The Technical Specifications contained in Appendi and the 'ironmental Protection Plan contained Appendix as revised through Amendment No. ~ are hereby incorporated into this license. Entergy Operations, Inc. shall operate the facility in accordance with the Technical Specifications and the Environmental Protection Plan.

The Surveilla~ce Requirements (SRs) for Diesel Generator 12 contained in the Technical Specifications and listed below, are not required to be performed immediately upon implementation of Amendment No. 1il The SRs listed below shall be successfully demonstrated at the next regularly scheduled performance.

SR 3.8.1.9, SR 3.8.1.10, and SR 3.8.1.14 Amendmen t 177 4

Attachment 2 to GNRO 2008-00013 Page 2 of 7 AC Sou rees - Opel" at i ng 3.8.1 ACTIONS (continued)

CONDITION REQUIRED ACTION COMPLETION TIME H. Three or more requi red H.1 Enter LCD 3.0.3. Immediately AC sources inoperable.

SURVEILLANCE REQUIREMENTS SURVEILLANCE FREQUENCY SR 3.8.1.1 Verify correct breaker alignment and 7 days indicated power availability tor each requi red offsite circuit.

SR 3.8.1.2 -.------~----------NOTE-------------------*

All DG starts may be preceded by an englne

• I .... --1INSERT I prelube peri od and followed by a warmup period prior to loading.

-~---------------~-----~------~------------

Verify each DG starts from standby 31 days conditions and achieve 1

IDELETE ~~ if! ~ 10 SeCeI98S, velta§ ~ 3744 \I i aflG fl eqt:\efley <2 58.8 liz, 8nd

-~. ;IsteadY state voltage, 3744 V and ~

~, 4576 V and frequency 2 58.8 Hz and :s: 61.2 Hz.

(continued)

GRAND GULF 3.8-5 Amendment No. +34, 142

Attachment 2 to GNRO 2008-00013 Page 3 of 7 INSERT for TS 3.8.1 (SR 3.8.1.2)

---

N 0 TES-------------------------------------

1. Performance of SR 3.8.1.21 satisfies this SR.

2. All DG starts may be preceded by an engine prelube period and followed by a warmup period prior to loading.

3. A modified DG start involving idling and gradual acceleration to synchronous speed may be used for this SR as recommended by the manufacturer. When modified start procedures are not used, the time, voltage, and frequency tolerances of SR 3.8.1.21 must be met.

Attachment 2 to GNRO 2008-00013 Page 4 of7 AC Sources -Operat i 09 3.8.1 SURVEILLANCE REQUIREMENTS (continued)

SURVEILLANCE FREQUENCY SR 3.8.1. 3 -------------------NOTES-------------------

1. OS loadings may include gradual loading as recommended by the manufacturer.

2. Momentary transients outside the load range do not inva1idate this test.

3. This Surveillance shall be conducted on only one DG at a time.

4. This SR shall be preceded by, and immediately follow t without shutdown, a succe'ssful oerformance of ~I-I I ADD I

_____ ~~_~:~:~:~j.JorSR 38.1. 21 1... __

I Delete"." I Verify each DG operates for ~ 60 minutes 31 days at a load e!:: 5450 kW and s 5740 kW for DG 11 and OG 12, and e!:: 3300 kW for DG 13.

SR 3.8.1.4 Verify each OG day tank contains ~ 220 gal 31 days of fuel oil.

SR 3.8.1.5 Check for and remove accumulated water from 31 days each day tank.

SR 3.8.1.6 Verify the fuel oil transfer system 31 days operates to automatically transfer fuel oil from the storage tank to the day tank.

SR 3.8.1. 7 Verify the load shedding and sequencing 31 days panels respond within design criteria.

(continued)

GRANO GULF 3.8-6 Amendment No. ~t 134

Attachment 2 to GNRO 2008-00013 Page 5 of7 AC Sources - Operati ng 3.8.1 SURVEILLANCE REQUIREMENTS (continued)

SURVEILLANCE FREQUENCY*

SR 3.8.1.20 -------------------NOTE--------------------

All DG starts may be preceded by an engine prelube period.

Verify, when started simultaneously from 10 years standby condition, each DG achieves:

a. in:>: 10 seconds, vol tage z 3744 V and frequency z 58.8 Hz; and

b. steady state voltage ~ 3744 V and s 4576 V and frequency z 58.8 Hz and s 61. 2 Hz.

SR 3.8. 1.21 GRAND GULF 3.8-16 Amendment No. ~, 142

Attachment 2 te GNRO 2008-00013 Page 6 of 7 INSERT for TS 3.8.1 (SR 3.8.1.21)

SR 3.8. 1.21 --------------------------------N aTE-----------------------------------

All DG starts may be preceded by an engine prelube period and followed by a warmup period prior to loading.

Verify each DG starts from standby conditions and achieves: 184 days

a. in S 10 seconds, voltage ~ 3744 V and frequency ~ 58.8 Hz; and

b. steady state voltage ~ 3744 V and S 4576 V and frequency ~ 58.8 Hz and S 61.2 Hz.

Attachment 2 to GNRO 2008-00013 Page 7 of 7 AC Sources-Shutdown 3.8.2 SURVE1LLANCE REOUIREMENTS SURVEILLANCE FREQUENCY SR 3.8.2.1 -_**_*_*_-_*_-*-~--NOTES-------_* __ *_------

1. The following SRs are not required to be performed: SR 3.8.1.3. SR 3.8.1.9 through SR 3.8.1.11. SR 3.8.1.13 through SR 3.8.1.16, SR 3.8.1.18, and SR 3.8.1.19.

2. SR 3.8.1.12 and SR 3.8.1.19 are not required to be met when the associated ECCS subsystemCs) are not required to be OPERABLE per LeO 3.5.2, "EGeS -

Shutdown."

For AC sources reqUired to be OPERABLE, the In accordance following SRs are applicable: with applicable SRs SR 3.8.1.1 SR 3.8.1.7 SR 3.8.1.14 SR 3.8. 1. 2 SR 3.8.1.9 SR 3.8.1.15 SR 3.8.1.3 SR 3.8.1.10 SR 3.8.1.16 SR 3.8.1. 4 SR 3.8.1.11 SR 3.8.1.18 SR 3.8.1. 5 SR 3.8.1.12 SR 3.8.1.19 SR 3.8.1.6 SR 3.8.1.13 ISR 3. 8. 1. 21 I GRAND GULF 3.8-21 Amendment No. ~, ~

Attachment 3 GNRO-2008/00013 Technical Specification Bases Changes (mark-up)

Attachment 3 to GNRO 2008-00013 Page 1 of 4 AC Sources - Operati ng B 3.8.1 BASES SURVEILLANCE SR 3.8.1.2IandSR 3.8.1.21 ~

REQUIREMENTS (continued) ~ helps to ensure the availability of the standby electrical power supply to mitigate DBAs and transients and REPLACE WITH: maintain the unit in a safe shutdown condition. ~------------~

These REPLACE WITH:

wea r on mavi n9 pa rts that do not get These SRs have been the engine is not running, iRis SR is ADD: s a.:ll"1'HH'o" to indicate that all DG starts for~

may be preceded by an engine prelube period and REPLACE WITH: a warmup period prior to loading. ~--~----~

REPLACE WITH:

Notes (the Note for SR 3.8.1.21 these and Note 2 for SR 3.8.1.2) purposes of this testing. the DGs are started from standby conditions. Standby conditions for a DG mean that ~--------~

the diesel engine coolant and oil are be4ng continuously ADD: s circulated and temperature is being maintained consistent with manufacturer recommendations for DG 11 and DG 12. For DG 13, standby conditions mean that the lube oil is heated by the jacket water and continuously circulated through a portion of the system as recommended by the vendor.. Engine

. jacket water ; s heated by an immersi on heater and ci rcul ates L...-I_N_S_ER_T_A--J.~ through the system by natural ci reul ati on. ADD at a 184 day frequency,

r IREPLACE WITH: 21 I SR ~ requi res that the DG starts from standby I conditions and achieves required voltage and frequency within 10 seconds. The DG's ability to maintain the required voltage and frequency is tested by those SRs which require DG loading~ The 10 second start requirement ADD: The start requirements supports the assumptions in the design basis LDCA analysis may not be applicable to (Ket. 5). In addi t i on to the SR requi rements, the ti me* for (INSERT B) the DG to reach steady state operation is periqdically .

monitored (data is taken ~ lQ~s~ceper 6 months during the performance of SR 3.8.1.~ and the trend evaluated to identify degradation of governo and voltage regulator performance.

---

IREPLACE WITH: 21 The DGs are started for this test by using one of the followi~g signals: manual. simulated loss of offsite power by itself, simulated loss of offsite power in conjunction with an ESF actuation test signal, or an ESF actuation test signal by itself.

(continued)

GRAND GULF B 3.8-15 LDC 99050

Attachment 3 to GNRO 2008-00013 Page 2 of 4 INSERT "A" for Bases 3.8.1 (SR 3.8.1.2 and SR 3.8.1.21)

In order to reduce stress and wear on diesel engines, the manufacturer recommends that the DGs be gradually accelerated to synchronous speed prior to loading. These modified start procedures are the intent of Note 3 of SR 3.8.1.2, which is only applicable when such procedures are used.

INSERT "B" for Basis 3.8.1 (SR 3.8.1.2 and SR 3.8.1.21 (continued))

3.8.1.2 (see Note 3 of SR 3.8.1.2), when a modified start procedure as described above is used. If a modified start is not used, the start requirements of SR 3.8.1.21 apply. Since SR 3.8.1.21 does require a 10 second start for each DG, it is more restrictive than SR 3.8.1.2, and it may be performed in lieu of SR 3.8.1.2. This is the intent of Note 1 of SR 3.8.1.2.

Similarly, the performance of SR 3.8.1.12 or SR 3.8.1.19 also satisfies the requirements of SR 3.8.1.2 and SR 3.8.1.21.

Attachment 3 to GNRO 2008-00013 Page 3 of 4

/i.e Sources - Operati ng B 3.8.1 ADD: and SR 3. 8.1.21 BASES REPLACE WITH:

SURV EI LLANCE SR 3.8.1.2 These Frequencies REQUIREMENTS The 31 day Frequency for SR 3.8.1.2 is consistent with the ADD: The 184 day frequency for industry guidelines for assessment of diesel generator SR 3. 8. 1. 21 is a reduction in performance (Ref. 14)~ This ~PQ~WeAGY provides adequate cold testing consistent with assurance of DG OPERABILITY, while minimizing degradation Generic Letter 84-15 (Ref. 7) resulting from testing.

SR 3.8.1.3 This Surveillance demonstrates that the DGs are capable of synchronizing and accepting greater than or equal to the equivalent of the maximum expected accident loads. A minimum run time of 60 minutes is required to stabilize engine temperatures, while minimizing the time that the DG is connected to the offsite source.

(continued).

GRAND GULF B 3.8-15a LOC 99050

Attachment 3 to GNRO 2008-00013 Page 4 of 4 AC Sources - Operati ng B 3.8.1 BASES SURVEILLANCE SR 3.8.1.20 (continued)

REQUIREMENTS This surveillance is performed when the unit is shut down and its 10 year Frequency is consistent with the recommendations of Regulatory Guide 1.9 (Ref. 3).

This SR is modified by a Note. The reason for the Note is to minimize wear on the DG during testing. For the purpose of this testing, the DGs must be started from standby conditions, that is, with the engine coolant and oil continuously circulated and temperature maintained consistent with manufacturer recommendations for DG 11 and DG 12. For DG 13, standby conditions mean that the lube oil is heated by the jacket water and continuously circulated through a portion of the system as recommended by the vendor. Engine jacket water ;s heated by an immersion heater and circulates through the system by natural circulation.

ADD:

(See SR 3. 8.1.2)

(continued)

GRAND GULF B 3.8-33 LOC 02003