ML20011E822
| ML20011E822 | |
| Person / Time | |
|---|---|
| Site: | McGuire, Mcguire  |
| Issue date: | 02/10/1990 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML20011E819 | List: |
| References | |
| NUDOCS 9002220533 | |
| Download: ML20011E822 (3) | |
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UNITED STATES
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g NUCLEAR REGULATORY COMMISSION 3
a WASHINoTON, D, C. 70006 SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION j
t RELATED TO AMENDMENT NO.102 TO FACILITY OPERATING LICENSE NPF-_9 AND RENOMENT NO. 84 TO FACILITY OPERATING LICENSE NPF-17 i
OUKE POWER COMPANY f
00CKETS NOS. 50-369 AND 50-370 MCGUIRE NUCLEAR STATION, UNITS 1 AND 2 1
1.0 INTRODUCTION
By letter dated September 15, 1989, Duke Power Company (the licensee) proposed amendments to the McGuire Nuclear Station Technical Specifications (TSs) which would (1) make two changes to TS Table 3.3-4, Engineered Safety Features Actuation System Instrumentation Trip Setpoints, to correct and better define a trip setpoint and allowable value, and (2) change TS Table 3.3-5, Enginected Safety Features Response Times, to add appropriate response times to three items and revise the present value of the response time of 3 fourth item.
2.0 EVALUATION 2.1 Table 3.3-4 The first proposed change to TS Table 3.3-4, Item 4.d, Negative Steam Line Pressure Rate-High, would delete the minus signs from the numerical values for the Trip Setpoint and the Allowable Values.
The heading for Item 4.d already i
indicates a " negative" rate of pressure change; the additional minus sign could cause confusion.
This change is for clarifying editorial purposes, and is, therefore, acceptable.
The second revision to Item 4.d of TS Table 3.3-4 would change the entry under Trip Setpoint from "5 100 psi /sec" to "5 100 psi with a rate / lag function time constant k 50 seconds." Similarly, the entry under Allowable Values would be changed from "5120 psi /sec" to "5120 psi with a rate / lag L
function time constant k 50 seconds." This change in format and method r
I of denoting the setpoints would correspond to the design of the as-built steam line pressure rate instrumentation and' ensure its performance consistent with safety analyses.
The numerical values were derived using the methodology L
discussed in the report " Westinghouse Reactor Protection System / Engineered
' Safety Features Actuation System Setpoint Methodology, Duke Power Company, McGuire Unit 1," by C. R. Tuley et al,, April 1981.
The methodology has been reviewed by the NRC staff and found to be acceptable.
l These clarifying changes correct the trip setpoint and allowable values consistent with the NRC's original intent and consistent with actual plant practice.
Accordingly, the changes are administrative in nature and do not involve changes to the actual values themselves or the manner in which they are used.
Consequently, the requested changes are acceptable.
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2.2 Table 3.3-5
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1 The proposed changes to TS Table 3.3-5, Items 2.e, 3.e, and 4.e would specify response times of 5 4 seconds for the Containment Purge and Exhaust Isolation systems for each of three initiating signals:
Containment Pressure-j High, Pressurizer Pressure-Low-Low, and Steam Line Pressure-Low.
At present, response times for Containment Purge and Exhaust Isolation are specified to be "N.A", i.e., not applicable.
This is incorrect since response times were considered in analyses of the offsite consequences of accidents involving the use of the Containment Purge and Exhaust System.
i The case of a loss of coolant accident (LOCA) concurrent with lower contain-ment pressure relief is analyzed in Section 15.B.2 of the McGuire Final Safety Analysis Report (FSAR).
One of the parameters used in the evaluation of this case is the isolation time for the Containment Air Release and Addition System valves. As indicated in FSAR Table 15.B.2-1, the isolation time for these valves in this analysis is 4 seconds.
The results of this analysis, i
shown in FSAR Table 15.0.12-1, are in compliance with the assumptions used in the plant licensing basis accident analysis.
Isolation times 5 4 seconds are therefore acceptable.
The proposed 5 4-second response times are consistent with FSAR Section 9.5.12.3 which indicates that these valves have a 3-second closure time, plus an allowable 1 second for generating an Engineered Safety Feature (ESF) response as indicated in FSAR Section 7.3.1.2.6.
The licensee also proposed a revision to Item 6 b of TS Table 3.3-5, which specifies the Engineered Safety Features Response Time addressing Feedwater Isolation based upon a Steam Generator Water Level-High-High signal.
The requested change would lower the required response time from the currently e
specified 5 13 seconds to 5 9 seconds.
The licensing basis safety analysis which determines this response time is excessive feedwater flow at full power, analyzed in FSAR Section 15.1.2.
FSAR Table 15.1.2-1 gives the sequence of events for this analysis.
The High-High Steam Generator Water Level setpoint is reached at 27 seconds, with feedwater isolation occurring at 36 seconds (i.e., 9 seconds later).
If feedwater flow continued for another 4 seconds, as permitted by the currently specified isolation time of 13 seconds, an additional mass increase beyond that assumed in the analysis could be expected.
This additional feedwater level could affect the consequences of the event at power, if there had been a trip, with potential effects on reactivity control (e.g., power. restoration) and/or overfill of the steam generator to cause water ingress (i.e., flooding) into the main steam lines.
Additionally, it could have consequences of potentially larger importance for the event occurring from sub-critical zero power.
Therefore, the proposed lowering of the required isolation response time from 5 13 seconds to 5 9 seconds is required to make it consistent with the licensing basis.
The requested change to Item 6.b of TS Table 3.3-5 is, therefore, acceptable.
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3.0 ENVIRONMENTAL CONSIDERATION
These amendments-involve changes in requirements with respect to the installation or use of facility components located within the restricted area as defined in 10 CFR Part 20.
The staff has determined that the amendments involve no significant. increase in the amounts, and no significant change in the types, of arty effluents that may be released offsite and that there is no significant incre'ase in individual or cumulative occupational exposure.
The Commission has previously published a proposed finding that the amendments involve no-significant hazards consideration, and there has been no public comment on i
such finding.
Accordingly, the amendments meet the eligibility criteria for categorical exclusion set forth in 10 CFR 51.22(c)(9).
Pursuant to 10 CFR 51.22(b), no environmental impact statement or environmental assessment need be prepared in connection with the issuance of these amendments.
4.0 CONCLUSION
The Commission made a proposed determination that the amendments involve no significant hazards consideration which was published in the Federal Register (55 FR 931) on January 10, 1990.
The Commission consulted with the State of North Carolina.
No public comments were received, and the State of North Carolina did not have any comments.
We have concluded, based on the considerations discussed above, that:
(1) there is reasonable assurance that the health and safety of the public will not be endangered by operation in the proposed manner, and (2) such activities will be conducted in compliance with the Commission's regulations, and the i
issuance of these amendments will not be inimical to the common defense and security or to the health and safety of the public.
Principal Contributors:
D. Hood, PDII-3/ORP-I/II S. Kirslis, PDII-3/0RP-1/II Dated: February 10, 1990
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