ML20081C276
| ML20081C276 | |
| Person / Time | |
|---|---|
| Site: | Nine Mile Point  |
| Issue date: | 03/08/1995 |
| From: | Sylvia B NIAGARA MOHAWK POWER CORP. |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| NMP2L-1529, NUDOCS 9503170188 | |
| Download: ML20081C276 (6) | |
Text
,
M Y NIAGARA RUMOHAWK
, MAGARA MOHnWK POWER cORPORAnoN/NINE MILE POINT, P.O. BOX 63 LYCOMING, NY 13093/ TELEPHONE (315) 349-2882 B. Ratph Sylvia
' Executive Vice President i
Nuclear March 8,1995 NMP2L 1529 U. S. Nuclear Regulatory Commission Attn: Document Control Desk Washington, DC 20555 RE:
Nine Mile Point Unit 2 Docket No. 50-410 NPF-69
Subject:
Pmposed License Amendment - Upmted Opemtion, Response to Requestfor Additional hfonnation Gentlemen:
In a letter to the Nuclear Regulatory Commission (NRC) dated July 22,1993 (NMP2L 1397), Niagara Mohawk Power Corporation (NMPC) proposed a license amendment to allow Nine Mile Point Unit 2 (NMP2) to operate at an uprated power of 3467 megawatts thermal.
During the course of the Staff's review of this proposed license amendment, the NRC has determined that additional information regarding instrument setpoint methodology, as identified in its letter to NMPC dated February 24,1995, is required to complete its review of this matter. Attached to this letter is the requested additional information.
Niagara Mohawk has provided a copy of this response to the appropriate state representative.
Very truly yours, B. Ralph Sylvia Executive Vice President - Nuclear BRS/KWK/kab Attachment I
l 9503170188 950308
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Regional Administrator, Region I Mr. B. S. Norris, Senior Resident Inspector Mr. L. B. Marsh, Director, Project Directorate 1-1, NRR
~ Mr. D. S. Brinkman, Senior Project Manager, NRR Ms. Donna Ross Division of Policy Analysis and Planning New York State Energy Office Agency Building 2 Empire State Plaza i
Albany, NY 12223 Records Management r
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G ATTACIIMENT Reauest for AdditionalInformation The licensce's submittal for power uprate does not discuss the instrument setpoint methodology. The NRC staffis unable to determine whether the GE setpoint methodology discussed in GE Topical Report NEDC-31336 is used, or a plant specific setpoint methodology has been used for this application.
If a plant specific setpoint methodology is used, then provide the following information:
l.
Discuss your setpoint methodology and include a discussion on how it differs from NEDC-31336.
2.
The calculations and related documents that were utilized to derive the new trip secpoint and allowable values for the following parameters:
a.
reactor vessel high pressure scram b.
high pressure ATWS RPT If the GE setpoint methodology is used, then provide the following information:
1.
Reference the GE topical report in this report.
2.
The NRC staff's Safety Evaluation Report (SER) on GE Topical Report NEDO-i 31336, identified certain plant specific information needed to justify the application of the report. Provide a discussion regarding the applicability of the topical report.
3.
Confirm that the calculation for the instrument setpoint is identical to the plants previously reviewed by the NRC staff for power uprate (e.g., Fermi-2, WNP-2, Limerick I and 2, and Peach Bottom 2 and 3). If not, then justify the differences.
Also, for either methodology, provide the necessary information in either Table 5.1 or elsewhere for the NRC staff to determine if power uprate results in any decrease in the margins between the allowable value of instrument setpoints and analytical limit. Provide justification for any instrument where such condition occurs.
Resoonse General Electric (GE) Report NEDC-31336 was used to perform the power uprate setpoint calculations for NMP2. Prior to development of the relatively new GE setpoint methodology presented in NEDC-31336, NMP2's current rated setpoints were developed utilizing an older GE setpoint methodology. The current rated setpoints, which were developed utilizing the older methodology, were reviewed and confirmed to also be conservative or equal with respect to the new GE setpoint methodology of NEDC-31336.
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' To establish setpoints for power uprate conditions, affected setpoints were increased proportionately to the change in plant parameter due to power uprate conditiors. GE setpoint methodology NEDC-31336 was utilized to confirm that adequate margin is maintained for -
- power uprate conditions.
The GE setpoint methodology, governed by GE topical report NEDC-31336, is referenced m Appendix F, Section F.4.1, " Generic Instrument Setpoint Methodology" of Licensing Topical Report (LTR) NEDC-31897P-1, " Generic Guidelines for General Electric Boiling Water Reactor Power Uprate." The NMP2 Licensing Topical Report, NEDC-31994P, Section 5.1, l
identifies this as the applicable setpoint methodology by way of reference to "... Appendix F l
of Reference 5-1" in the first paragraph.
NEDC-31336 is a top-level reference document which has been approved for use by the NRC.. It defines the overall approach used in setpoint calculations. In addition (as noted in the NRC SER on NEDC-31336), each plant must provide its own plant-unique analysis for setpoints, which reflects plant-specific information. The plant-specific information pertains l
to:
l 1.
Operational plant parameters such as operating pressures, temperatures; 2.
Plant instrument data such as make, model no., range, span; 3.
Plant environmental data such as the trip environment (temperature, seismic, radiation) seen by the instrument, and 4.
Instrument drift which is a quantifiable, normally-distributed random variable (published design allowances used in setpoint calculations are validated by NEDC-32160P, BWROG LTR on Calibration Interval Extension, which is based on actual i
field data).
j Hence, the overall reference topical report NEDC-31336 and the plant-specific setpoint calculations (including plant-specific data) are both applicable to the NMP2 power uprate.
The calculation methodology is identical to previous power uprate setpoint calculations which used LTR NEDC-31336, including Fermi-2, WNP-2, Limerick I and 2, and Peach Bottom 2 l
and 3.
For setpoints using NEDC-31336, there is no decrease in margins, from current-rated power to uprated power. The following tables provide the margins for the pre and post uprate -
setpoints for Reactor Vessel High Pressure Scram and High Pressure ATWS RPT:
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TABLE 1A CALCULATED VALUES (PSIG) VIA NEDC-31336 CURRENT RATED CONDITION Margin Margin FUNCTION M
NTSP (AL-AV)
(AV-NTSP)
High Pressure 1071 1061 1054 10 7
Scram High Pressure 1080 1076 1069 4
7 ATWS RPT TABLEIB TECIINICAL SPECIFICATION VALUES (PSIG) FOR CONSERVATISM CURRENT RATED CONDITION Margin Margin FUNCTION M
ET_SJ12 (AL-AV)
(AV-NTSP)
High Pressure 1071 1057 1037 14 20 Scram High Pressure 1080 1065 1050 15 15 ATWS RPT TABLE 2A CALCULATED VALUES (PSIG) VIA NEDC-31336 POWER UPRATE CONDITION Margin Margin FUNCTION AL M
IEEE (AL-AV)
(AV-NTSP)
High Pressure 1086 1076 1069 10 7
Scram High Pressure 1095 1091 1084 4
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. TABLE 28
> TECHNICAL SPECIFICATION-VALUES (PSIG) FOR CONSERVATISM-t h
POWER UPRATE CONDITION
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. Margin _
Margin FUNCTION AL AT NISE (AL-AV)
(AV-NTSP)
' High Pressure 1086' 1072 1052 14 20 I
Scram High Pressure
-1095 1080 1065 15 15 ATWS RPT TERMS lAL =. Analytical Limit
- AV = Allowable Value
' NTSP = Nominal Trip Setpoint Each table shows the calculated margin between AL/AV and AV/NTSP for each of the
' instrumentation functions. By comparing Table 1 A and 2A, it can be seen that the margins o
for pre and post-uprate conditions are the same, Tables IB and 2B reflect the calculated margins based on the Technical Specification values that were selected with additional conservative margin included. A comparison of Tables 1B.
l and 2B also illustrates that the same margins are maintained for pre and post-uprate l
conditions.
. Hence, it is concluded that the margins for a given function utilizing NEDC-31336 are not decreased from pre to post-uprate conditions.
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