ML19289F536
| ML19289F536 | |
| Person / Time | |
|---|---|
| Site: | Trojan File:Portland General Electric icon.png |
| Issue date: | 06/06/1979 |
| From: | Broehl D PORTLAND GENERAL ELECTRIC CO. |
| To: | |
| Shared Package | |
| ML19289F534 | List: |
| References | |
| TAC-11843, NUDOCS 7906110136 | |
| Download: ML19289F536 (9) | |
Text
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PORTLAND GENERAL ELECTRIC COMPANY EUGENE WATER & ELECTRIC BOARD AND PACIFIC POWER & LIGHT COMPANY TROJAN NUCLEAR PLANT Operating License NPF-1 Docket 50-344 License Change Appl' cation 54 This License Change Application is submitted in support of Licensee's intent to modify the engineered safeguard features actuation logic in the pressurizer. The change is from coincident low pressurizer pressure and low pressurizer level to a two out of three low pressurizer pressure logic alone.
PORTLAND GENERAL ELECTRIC COMPANY By V
D. J. Brochl Assistant Vice President Generation Engineering-Construction Division Subocribed and sworn to before me this 6th day of June, 1979.
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r> w Notary Public of Oreg%n My Commission Expires:
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2230 305 DJB/JGL/4gah2B2 790611013 6
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LCA 54 Page 1 of 2 LICENSE CHANGE APPLICATION 54 Change the Technical Specifications to delete all references to coincident pressurizer level and pressurizer pressure signals for engineered safety features actuation. Substitute a two out of three logic system based on pressurizer pressure alone. The following list of affected tables are included in Attachment A in their modified form:
a) Table 3.3-3, Page 3/4 3-15 b) Table 3.3-3, Page 3/4 3-21 c) Table 3.3-4, Page 3/4 3-22 d) Table 3.3-5, Page 3/4 3-26 e) Table 4.3-2, Page 3/4 3-29 REASON FOR CHANGE This change will preclude actuation delays for ESF equipment caused by nonstandard water level responses associated with small break LOCAs in the pressurizer steam space. For this patricular break location, the water level in the pressurizer will increase initially, thereby defeating the present coincident low pressurizer level and pressurizer pressure safety injection logic. This application for an ESF logic system based solely on pressurizer pressure signals would eliminate this delay inherent in the present system.
SAFETY EVALUATION Implementation of this change will not adversely affect any of the previously performed accident analyses and no new accidents are created.
Other than a more rapid ESF response to the small-break LOCAs from the pressurizer steam space, the impact of this change is negligible.
No environmental impacts will result since this is only a change to elec-tronic circuitry and will not change any previously determined environ-mental impacts.
These conclusions are based on a review of FSAR Sections 6.3, 7.2, 7.3, 15.4 and 16.3, the Technical Specifications and the Westinghouse Safety Evaluation (copy attached).
In addition to reviewing those pages and tables directly affected by the proposed modifications, a survey was conducted of other accident scenarios to determine whether they would be adversly affected by this change to the ESF logic.
In all cases, the actuation of safety injection would occur either at the same time as previously analyzed or slightly before. Furthermore, the removal of coincident pressurizer water level signals from the ESF logic will neither affect level indications in the control room nor the high water level reactor trip.
2230 306
LCA 54 Page 2 of 2 LICENSE CHANGE APPLICATION 54 As evidenced by these findings, the proposed change will not cause any negative impacts on Plant safety, and for the one case of a small LOCA in the pressurizer steam space, a very positive impact will result.
SCHEDULE CONSIDERATIONS In order that we may implement this design change as soon as is practicable we request review and approval by June 25, 1979. This time table would permit the required equipment modifications to take place during the current scheduled outage.
2230 s07 JCL/4gah2B3
TABLE 3.3-3 h
ENGINEERED SAFETY FEATURE ACTUATION SYSTEM INSTRUMENTATION
$7 MINIMUM TOTAL NO.
CHANNELS CHANNELS APPLICABLE y
FUNCTIONAL UNIT OF CHANNELS TO TRIP OPERABLE MODES ACTION 1.
SAFETY INJECTION AND FEEDWATER IS0'_ATION a.
Manual Initiation 2
1 2
1,2,3,4 18 b.
Automatic Actuation 2
1 2
1,2,3,4 13 Logic c.
Containment 3
2 2
1,2,3 14 jd Pressure-High Y
d.
Pressurizer 3 pressure 2
2 1, 2, 3#
14
}l Pressure-Low e.
Differential 1, 2, 3##
Pressure Between Steam Lines - High Four Loops 3/ steam 2/ steam 2/ steam 14 Operating line line, any line steam line rs) rs)
Three Loops 3/ operating 1###/ steam 2/ operating 15
[{d Operating steam line line, any steam line operating steam line t,a C:3 CD
TABLE 3.3-3 (Continued)
- b. Above P-11 or P-12, demonstrate that the Minimum C4annels OPERABLE requirement is met within 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br />; operation may continue with the inoperable channel bypassed and one additional channel may be bypassed for up to 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> for surveillance testing per Specification 4.3.2.1.
ACTION 17 - With less than the Minimum Channels OPERABLE, operation may continue provided the containment ventilation valves are maintained closed.
ACTION 18 - With the number of OPERABLE Channels one less than the Total Number of Channels, restore the inoperable channel to OPERABLE status within 48 hours5.555556e-4 days <br />0.0133 hours <br />7.936508e-5 weeks <br />1.8264e-5 months <br /> or be in at least HOT STANDBY within the next 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> and in COLD SHUTDOWN within the following 30 hours3.472222e-4 days <br />0.00833 hours <br />4.960317e-5 weeks <br />1.1415e-5 months <br />.
ENGINEERED SAFETY FEATURES INTERLOCKS DESIGNATION CONDITION AND SETPOINT FUNCTION P-11 With 2 of 3 pressurizer Prevents or defeats man-pressure channels > 1925 ual block of safety in-psig.
jection actuation on low pressurizer pressure.
P-12 With 3 of 4 Tavg channels Prevents or defeats
> 553*F, manual block of safety injection actuation high steam line flow and low steam line pressure.
With 2 of 4 Tavg channels Allows manual block of
< 553*l' safety injection actua-tion on high steam line flow and low steam line pressure. Causes steam line isolation on high steam flow. Affects steam dump blocks.
R230 309 TROJAN-UNIT 1 3/4 3-21
TABLE 3.3-4 ENGINEERED SAFETY FEATURE ACTUATION SYSTEM INSTRUMENTATION TRIP SETPOINTS FUNCTIONAL UNIT TRIP SETPOINT ALLOWABLE VALUES E
N 1.
SAFETY INJECTION, TURBINE TRIP AND FEEDWATER ISOLATION a.
Manual Initiation.
Not Applicable Not Applicable b.
Automatic Actuation Logic.
Not Applicable Not Applicable c.
Containment Pressure--High.
< 5 psig
< 5.5 psig d.
Pressurizer Pressure--Low.
> 1765 psig
> 1755 psig y
Between Steam Lines--High.
~< 112 psi e.
Differential Pressure
<100 psi Y
f.
Steam Flow in Two Steam
< A function defined as
< A function defined as U
Lines--High Coincident with Tollows: 40% of full steam Tollows: 44 % of full
-Low-Low or Steam flow between 0% and 20% load stean flow between 0% and Tavg Pressure--Low Line and then increasing linearly 20 % load and then increasing to 110% of full steam flow linearly to 111.5% of full at full load full steam flow at full load
> 553*F
>5
-> 551*F Tav00psigsteamline Tavb0psigsteamline
>6 g
N Pressure.
pressure.
Lea CD Lea
TABLE 4.3-2 ENGINEERED SAFETY FEATURE ACTUATION SYSTEM INSTRUMENTATION g
SURVEILLANCE REQUIREMENTS T
E CHANNEL MODES IN WHICH U
CHANNEL CHANNEL FUNCTIONAL SURVEILLANCE FUNCTIONAL UNIT CHECK CALIBRATION TEST REQUIRED 1.
SAFETY INJECTION AND FEEDWATER ISOLATION a.
Manual Initiation N.A.
N.A.
M(1) 1, 2, 3, 4 b.
Automatic Actuation Logic N.A.
N.A.
M(2) 1, 2, 3, 4 c.
Containment Pressure-High S
R M(3) 1, 2, 3
[
d.
Pressurizer Pressure-Low S
R H
1,2,3 b
e.
Differential Pressure S
R M
1, 2, 3 Between Steam Lines--High f.
Steam Flow in Two Steam S
R M
1,2,3 Lines--High Coincident with Tavg--Low or Steam Line Pressure--Low 2.
N a.
Manual Initiation N.A.
N.A.
M(1) 1, 2, 3, 4 u
O b.
Automatic Actuation Logic N.A.
N.A.
M(2) 1, 2, 3, 4 h
c.
Containment Pressure--High-S R
M(3) 1, 2, 3 High O
- )
y
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Electric Corpcration Company sums Pittsturg'iPennsylvants 15233 May 11,1979 POR-79-533
. Mr. R. L. Sullivan Project Administrative Engineer Portland General Electric Company 121 S. W. Salmon Street Portland, Oregon 97204
Dear Mr. Sullivan:
Attention:
J.L. Frewing
Subject:
, Pressurizer Pressure SI Actuation Logic P.O. N-144 68
-G.O. PO-82521 Transmitted are the (a) Safety Evaluation Report and (2) Technical Specification Mark-ups for the Trojan pressurizer pressure safety injection actuation logic.
(1)
Trojan Pressurizer Level / Pressure Coincidence Modification Safety Evaluation (2)
Technical Specification Mark-ups
'J'able 3.3-3 Table 3.3-4 Table 3.3-5 Table 4.3-2 Drawing 5655D34 Sheets 6 and 11 Very truly yours, f
L. R. Cun ngham, Manager Western & Far East Region Nuclear Service Division IRC/dmc
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cc: J. L. Frewing 2230 31' B. D. Withers S
J. W. Martindell-V_{
3 TROJAN (POR) Pressurizer Level / Pressure Coincidence
~
Modification Safety Evaluation As requested by Portland General Electric Ccmpany, Westinghouse has performed a safety review of safety injection actuation logic modifica-tions for application to the Trojan Nuclear Unit.
The existing logic will be modified by celeting the low pressurizer pressure coincident with low pressurizer level actuation logic and converting the protection system to a two-out-of-tnree low pressurizer pressure actuation only.
Figures 1 and 2 show the existing and modified logic diagrams respectively.
The basis for this modification utilizes three of the four existing pressurizer pressure channels for safety injection actuation and two of the four channels for control system functions.
Control and protection
. requirements set forth in IEEE-279, are addressed by interlocking two separate pressure control channels such that a single pressure trans-mitter f ailure will not cause power operated relief valve actuation.
This is accomplished by raising all the pressure bistables for the power operated relief valve interlocks to 2350 psia.
The remaining heater control and pressurizer spray valve control system functions are not
. : interlocked since inaavertent actuation does not require safeguards actuation.
All current ECCS analyses are valid and appropriate for plants with
. safety injection initiation'as a function of pressurizer pressure
. signals only. Previously safety injection was initiated on coincident
. -.,pressur zer pressure and level signals. The effect of changing to a i
pressure only signal will result in either an earlier initiation of safety injection, or no change in the time of safety injection initia-
. tion for cll break locations.
For small breaks in the pressurizer the pressure cnly signal will assure SI actuation. Therefore, current small break analysis assumptions concerning safety injection initiation time are appropriate.
Additionally, the effect of safety injection initia-tion time on peak clad temperature is negligible when initiation times being considered correspond to RCS pressures above 14CO psia.
The switch to a pressure only safety injection signal results in a negli-gible impaci. on large break analyses.
We have determined that the logic changes described above are acceptable for the Trojan Unit.
Recomended technical specifications for the Trojan Plant are attached.
These changes are based upon the technical specifications currently available to Westinghouse. The Utility should verify that these changes 4re applicable to their plant.
2230 313 yg_.
e-_
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