ML17264A411
| ML17264A411 | |
| Person / Time | |
|---|---|
| Site: | Ginna  |
| Issue date: | 03/15/1996 |
| From: | Mecredy R ROCHESTER GAS & ELECTRIC CORP. |
| To: | Andrea Johnson NRC (Affiliation Not Assigned), NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| NUDOCS 9603250170 | |
| Download: ML17264A411 (7) | |
Text
CATEGORY 1 REGULA:O.
F INFORMATION DISTRIBUTION/STEM (RIDE)
ACI ES<l.gN P4BR:9603250170 DOC.DATE: 96/03/15 NOTARIZED:
NO FACILE~'6r F44 Robert Emmet Ginna Nuclear Plant, Unit 1, Rochester G
AUTH. ',vAME AUTHOR AFFILIATION MECRED'8,R.C.
Rochester Gas
& Electric Corp.
RECIP.NAME RECIPIENT AFFILIATION JOHNSON,A.R.
DOCKET ¹ 05000244 St'BJI.CT: Submits remaining responses re 960209 LAR for LTOP,raised by CY Liang.Issues 1
6 resolved during 960313 conference C
call.
A DISTRIBUTION CODE:
AOOID COPIES RECEIVED:LTR 1
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TITLE: OR Submittal: General Distribution T
NOTES:License Exp date in accordance with 10CFR2,2.109(9/19/72).
05000244 E
INTERNAL RECIPIENT ID CODE/NAME PD.'-1 LA JOHNSON,A NRR/DRCH/HICB NRR/DSSA/SRXB OGC/HDS3 COPIES LTTR ENCL 1
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0 RECIPIENT ID CODE/NAME PD1-1 PD NRR/DE/EMCB NRR/DSSA/SPLB NUDOCS-ABSTRACT COPIES LTTR ENCL 1
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N NOTE TO ALL "RIDS" RECIPIENTS:
PLEASE HELP US TO REDUCE WASTETH CONTACT THE DOCUMENT CONTROL DESKS ROOM OWFN SD-5'(EXT. 415-2083)
TO ELIMINATE YOUR NAME FROM DISTRIBUTION LISTS FOR DOCUMENTS YOU DON'T NEED!
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C3 AND ROCHESlER GASANDEIECTRIC CORPORATION ~ 89 EASTAVENUF, ROCHESTER, N. Y Idbf9-0001 ARFA CODE718 548-2700 ROBERT C. MECREDY Vice President Nvdeor operations March 15, 1996 U.S. Nuclear Regulatory Commission Document Control Desk Attn:
Allen R. Johnson Project Directorate I-3 Washington, D.C.
20555
Subject:
Response to NRC Questions Related to February 9, 1996 LAR for LTOP.
R.E.
Ginna Nuclear Power Plant Docket No. 50-244 In response to the subject submittal, six questions were raised by C Y Liang, the NRC reviewer.
These were discussed in a conference call on March 13,
- 1996, and issues 1 and 6 were resolved at that time.
The remaining responses are provided in the attachment.
GJW:lrc Very Truly Yo rs Robert C. Mecredy Vice President, Nuclear Operations 9b03250i70 qb03i5 PDR ADOCK 05000244
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Attachment:
Issue (1):
Pag'e 5 of the Low Temperature Overpressure Analysis Summary Report (LTOASR) indicates that the heat addition events are analyzed at RCS temperatures of 85 F and 320 F.
Discuss why 320 F is the maximum credible temperature at which a
secondary to primary temperature difference of 50 F
can be achieved.
Are there any operating procedures which would prevent startup of a reactor coolant pump at an RCS temperature less than 320?
Response
Issue (2):
Response
not required per telecon 3/13/96.
Page 7 of the LTOASR indicates that the PORVs are set to lift when the pump suction pressure on the loop with the pressurizer exceeded 430 psig.
Based on this criterion, what is the calculated setpoint for the PORVs including instrument uncertainties?
Response
Instrument uncertainty for the pressure loops is 18.5 psig.
Therefore the maximum allowable setpoint is 430 18.5 = 411.5 psig.
The setpoints are procedurally set to 410 psig.
Issue (3):
Page 7 of the LTOASR states that instrument error is not normally considered for Appendix G
protection but is included in the analysis for RHR overpressure concerns.
Provide clarification to confirm that the instrument errors are considered in 'he determination of the LTOP
- setpoint, consistent with the LTOP methodology document for Ginna.
Response
The report was written based on the current Ginna analysis.
Our new methodology requires instrument uncertainty to be included and the analysis does include instrument uncertainty (see response to item 2).
Issue (4):
Response
Page 13 of the LTOASR states that the analysis was terminated after 10= minutes when the operator was assumed to secure charging flow. 'riefly describe the operating procedures used and instrumentation relied on for the operator to terminate the event.
Justify that 10 minute operator action is a
reasonable assumption in the mass addition analysis.
Several indications are available to the operator including:
1.
Continuous recording of RCS pressure on the control board.
2.
MCB Annunciators for RCS Overpressure Protection Actuation.
Issue (5):
3.
MCB Annunciators for high RHR pressure.
4.
Charging pump status lights.
It should be noted that there are no signals to automatically start a charging pump.
Therefore the mass addition event could only be iniatiated as a
direct result of an operator action (i.e. starting an additional pump).
Thus, the operator would be in the position to quickly stop the pump.
Annunciator response procedures to the LTOPS actuation alarm require the operator to reduce RCS pressure.
This can only be accomplished by stopping charging pumps or increasing letdown flow, both of which are accomplished from the control room.
The 10 minute operator action time is considered very conservative for these actions.
Provide discussion on the LTOP enable temperature which is not addressed in the LTOASR.
Response
The LTOPS system is manually enabled prior to RCS temperature decrease below 330'F.
The basis is shown on PTLR Figure 1 and 2,
which inicates the limiting RTq~ at 1/4T is 210'F.
The basis for the enable temperature, shown in Section 3.4 of WCAP 14040, is at least RT<< + 90'F (i.e. 300'F).
The chosen value of 330'F is conservative.
This is unchanged by this analysis.
Issue (6):
Provide discussion of the supporting analysis for the vent size of 1.1 sq. in. which is not addressed in the LTOASR.
Answer:
Response
not required per telecon 3/13/96.
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