ML20083D994
| ML20083D994 | |
| Person / Time | |
|---|---|
| Site: | Calvert Cliffs  |
| Issue date: | 09/26/1991 |
| From: | Creel G BALTIMORE GAS & ELECTRIC CO. |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| TAC-81402, TAC-81403, NUDOCS 9110020095 | |
| Download: ML20083D994 (6) | |
Text
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D A LTIMORE j
GADAND ELECTRIC CHARLES CENTER
- P O. BOX 1475
- BALTIMORE. MARYLAND 21203-475 GLORot C CREEL vice pm smcu Noc t t a te r ewt us, u 0,1 s e ci-4 4 %
September 26,1991 U. S. Nuclear Regulatory Commission Washington, DC 20555 NITENTION:
Document Control Desk
SUBJECT:
Calvert Cliffs Nuclear Power Plant Unit Nos.1 & 2; Docket Nos. 50-317 & 50-318 Request fo. Additional Information Concerning BG&E's Request for Amendment. dated September 5.1991 (TAC Nos. 81402 and 81403)
REFERENCES:
(a)
Letter from Mr. D. G. Mcdonald, Jr. (NRC), to Mr. G. C. Creel (BG&E), dated September 17, 1991, Request for Additional Information Concerning Baltimore Gas and Electric Company's Request for Amendment to Operating Licenses for Calvert Cliffs Unit Nos.1 & 2 (b)
Letter from Mr. G. C. Creel (BG&E), to NRC Document Control Desk (NRC), dated September 5,1991, Request for Amendment to Operating Licenses Gentlemen:
The Baltimore Gas & Electric Company hereby responds to your request for additional information (Reference a). This information concerns BG&E's repst for amendment to the operating licens:s of Calvert Cliffs Unit Nos. I and 2 (Reference b).
A meeting was he!d between our technical stalTs concerning this rcquest for amendment on Septembei 19, 1991. Several additional questions were identified at that meeting which are also addressed in this letter. Responses to the written questions and those raised at the meeting are contained in the attachment to this letter.
With one exception, these responses do not change or supersede any information contained in the amendment request. The exception deals with the performance of a load test on the temporary diesel generator. In out amendment request, we committed to performing a load test for greater than 60 minutes. Upon consideration of 'he discussion held between our staffs, we commit to performing the load test for four hours. This is only a minor change to a commitment made in association with this license amendment request. It does not delete any previous commitments, nor does it add any new ones. Furthermore, there is no impact on any of the provisions contained in the proposed technical specificaticas and there are no changes to the safety analysis. Therefore, the (e,g)id *O /
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responses to these questions do not change or modify the Determination of Significant llazards presented in the amendment request (Reference b).
Should you have any further questions regarding this matter, we will be pleased to discuss them with you.
Very truly yours,
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for G. C. Creel Vice President - Nuclear linergy GCC/RliD/IlDM/bdm/ dim AtIachment cc:
D. A. Brune, lisquire J. II. Silberg. lisquire R. A. Capra. NRC D. G. MeDonald, Jr., N RC T. T. Martin, N RC L II. Nicholson, N RC R.1. McLean, DNR J.11. Walter, PSC
NITACllMENT ItESPONSES TO QUESTM)NS 1.
Itovide infortnation on the temporary diesel generator (TDG) reganling its design (make, size, type, etc.), operation, and maintenance. This infunnatwn shoidd cover a perhxl of 3 years that this TDG has been in use.
Tbc TDG which will be leased for the upcoming Calvert Clilfs Unit 2 maintenance outage has the following characteristics:
DissM G"nerator Number:
2 Manufacturer: Kato Manufactuter: General Motors Rating:
2200 kW (2750 KVA)
Detroit Diesel 3 Phase Model No.
16V-149TI 4160 (Y) Volts Rating:
2000 kW (continuous) 80% Power Factor 1800 RPM i
24V D.C llattery Start System The components are loemed in an enclosed trailer which includes in erior and exterior lighting and a complete set of controls. The system includes batteries and is " black start" capable (i.e., can start with no external power). Electric power will be supplied to inaintain the battery charger.
The particular TDG to be used for the upcoming outage is new and has experienced operation for init al testing, only.
i The TDG model to be used for the upcoming Unit 2 outage oas been manufactured for at least eight yearn. It is typically used to provide power to hospitals and military bases; both situations whe:c high reliability is iraportant. The vendor estimates the TDG's reliability to-be above 90%
2.
Describe whether the TDG will remain in its temporary location once it is horalled, or willit be installed and removed every refueling ou: age uhen the EDG 12 is to be irupected and maintained. Describe the installation details of the TDG, regarding housmg, cabling, and associated switchgear, etc. IVhere will this TDG be stored (or used) after its use or will it be retumed so the vendor.
The TDG will be installed for those outages when required by the proposed Action statement for EDG 12 inspection and maintenance and then removed and returned to the vendor.
A drawing of the TDG arrangement was provided in the amendment reauest. The TDG housing is described in Question 1. Cabling will be run in a cable tray plated on scaffolding The cabling will be connected to a 4 kV bus through aa existing circuit breaker. Further information on the switchgear is provided in Question 7.
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- 6JTACllM ENT 1(ESPONSES TO QUESTIONS 3.
Provide a copy of the 50.59 Safety Evaluation that has been perfonned showing that no impainnent to existing safety related equipment occurs due to the use of the TDG.
The 50.59 Safety Evaluation was reviewed by the NRC technical staff at the September 19,1991, meeting. The following summaiizes the results of the 50.59 Safety Evaluation.
The probability of occurrence or the consequences of an accident or malfunction of equipment important to safety previously evaluated in the safety analysis report is not increased.
b The TDG will remain isolated from the 4 kV bus by a Class IE circuit breaker unless a loss of offsite power has occurred.
The loss of offsite power while in shutdown modes (! or 6) is not a previously
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analyzed event.
The possibility for an accident or malfunction of a different type than any evaluated previou.;ly in the saiety analysis rt port is not created.
The ctarting and loading of the TDG will be administratively controlleA Missile and fire hazards are climinated by locating the TDG and tanker away from energized offsite power sources. This prevents a single event (turbine overspeed resulting in a missile or fuel fire) from simultaneously rendering the TDG unavailable and interrupting offsite power such that the TDG would be needed.
The margin of safety as defined in the technical specifications bases is not reduced.
The TDG is capable of carrying shutdown loads and maintaining indication and control for an extended period of time, 4.
Provide information or, the TDG load test (i.e., how long and at what level of kIVloading) that will be conducted to assure that the TDG can perform its intendedfunction.
The TDG "ill be load tested to greater than 1700 kW for four hours by paralleling the TDG to the olishe grid via the 4 kV bus. This is the same test methodology used to test our existing EDGs. Note that in our amendment request letter we committed to performing the load test for one bour. This represents a change to our amendment request.
5.
Proviac infonnation on whether you have derch> ped a procedure and trained operators for aligning, starting, connecting, and loading the TDG.
Procedures to implement this proposed configuration are currently under development.
Operations personnel will be trained (with the assistance from the TDG vendor) on the alignment, connection, and loading of the TDG.
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ATfAQ1Ml3NI ItESPONSES TO QUESTIONS Additional In[unn!!1 ion R_enuested at thc3sptember 19.1991. Merting 6.
- Provide infortnation to quantify the effects, if any, that this Technical Specification change will have on plant safety.
In response to the Station illackout Itule, Calvert Cliffs committed to maintain a target emergency diesel generator (EDGs) reliability of at least 97.596. livaluating the proposed change in a very simplistic fashion, EDG 12's function will be provided by the TDG for seven days out of every 18 months. or 1.39b of the time. 'lherefore, under the proposed change, the diesel generator reliability wih be (97.5% liDG reliability x 98.796 EDG availability) + (90%
TDG reliability x 1.39c TDG availability), or 97.4%; a 0.196 deetcase in everall dicsci generator reliabdity. This further supports to our conclusion in the amendment requ;st that this change does not icptesent a sigadicant increase in risk.
7.
Describe the details of the connection of the TDG to the plant emergency A.C. bus. Specifically, provide infonnation on the plant breaker rating, protective relaying. interntyt capacity, and breaker coordination.
The TDG will be connected to the 4 kV bus through an existing Class lE circuit breaker.
This breaker normally connects the liigh Pressure Safety injection (llPSI) pump to the 4 kV bus. The llPSI breaker is identical to the circuit breakers used to connect the EDGs to th<
4 kV bus. The TDG breaker is of a similar design. Their characteristics are:
in. Plant TDG
' Manufacturer General Electric General Electric Type AMII.4.76-2501 D AM.4.16-250-811 Rated Max Volts 4.76 kV 4.76 kV Rated Amps 1200 A 1200 A Impulse Withstand 60 kV 60 kV Interruption Time 5 eycles 5 cycles itated Short Circuit Amps 29 kA 20 kA Rated Voltage Range Factor 1.24 1.24 The llPSI breaker will have the protective relaying disabled along with the undervoltage and S!AS trips which in essence renders the device a switch. No coordination between the llPSI breaker and the TDG breaker is necessary. Closing the IIPSI breaker will be dont: according to the procedure to align the TDG. A review of the time / current coordination curves for the C
TDG breaker will be made against the breakers which feed large loads on the 4 kV bus to assure proper coordination exists.
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IWSI'ONSES TO QtlESTIONS H.
provide infonnation em the availability of r omnumications benveen the TDG operator and the control room during a loss of offite power.
Should a loss of of fsite power occur, communication between the control roora and the TDG operator will be by radio. The portable radios, which would be used by the o,,crator at the TDG, are powered by batteries and, therefore, will be available during a station blackout.
'the control room radio control unit is powered by a vital bus inverter and will not be lost.
The in plant iepeaters are powered by batteries and the Security diesel. The outside repeaters are powered by batteries. Therefore, portable radio mmmunications will be available in the event of a loss of offsite power.
Should portable radio communication be lost, the outside operators have standing instructions to report to the control rmmi.
4.
Procide information on what measures will be taken to ensure that maintenance work perfonned on the. shutdown unit will not inadvertently di:able the emergenty die:cl generator realigned to the operating unit.
The realigned EDG is designed to meet all the requirements of an operable A.C. power source to either Unit I or Unit 2. Unit specific support sy3 tem *. such as cooling water, circuit breakers, and initiation logic, will be provided from the operating unit.
Normal work control practices during the outage will p< event any work frorn affecting the EDG or its support systems.
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