ML20082D117

Proposed TS Table 3.2-A, Isolation Actuation Instrumentation

ML20082D117
Person / Time
Site:	Duane Arnold
Issue date:	03/28/1995
From:	IES UTILITIES INC., (FORMERLY IOWA ELECTRIC LIGHT
To:
Shared Package
ML20082D106	List: ML20082D117 NG-95-0934, Application for Amend to License DPR-49,consisting of Request for TS Change (RTS-282),revising TS Table 3.2-A, Isolation Actuation Instrumentation
References
NUDOCS 9504070299
Download: ML20082D117 (7)

Text

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$27 0 Table 3.2-A ISOLATION ACTUATION INSTRUNENTATION 4>

• N oR MINIH $ VALVE h n:s ne $ OPERABLE GROUPS APPLICABLE CHANNELS ISOLATED K4 f, OPERATING PER TRIP BY-04 2 TRIP FUNCTION TRIP LEVEL SETTING MODE SYSTEN SIGNAL ACTION UltA o ',

00* 'conucon Isola 11on Sianals

n$ g 1,2,3 2 2 20 t:(AJ

• w Reactor Water Level-Low a 110 Inches 1,2,3 and a 2 .l*

• 26

Dy 1,2,3 2 4,5 23

• -a Reactor Water Level - Low-Low-Low a 18.5 Inches 1,2,3 g 1 21

'$ 1,2,3 +4 7 20 Drywell Pressure - High 5 2.0 psig 1, 2 2 20 1,2,3 2 *'

26 I 4#

W I, 3, :vM _ _ _^ 1 g) 9' .t

, Hain Steam Line Isolation N

d, Main Steam Line Pressure - Low a 850 psig. 1 2 1 22 Main Steam Line Flow - High 5 140% of Mated 1,2,3 2/line 1 20 Steam Flow Condenser Backpressure - High 5 20 In. Hg 1,2**,3** 2 1 21 Main Steam Line Tunnel s 200*F 1,2,3 2/11.c 4 1 21 Temperature - High Turbine Building Temperature -

High s 200*F 1,2,3 4' 1 21 Main Steam Line Radiation - High s 3 x Normal Rated 1,2,3 2 3 ** 21 Power Background

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Ne Table 3.2-A (Continued) '

ISOLATION At;TuRTION InarnusunTATION

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b f3 MINIMUM VALVE _ .

OPERABLE GROUPS

, APPLICABLE OPERATING CHANNELS PER TRIP ISOLATED BY w TRIP FUNCTION TRIP LEVEL SETTING -MODE SYSTEMI '8 SIGNAL ACTION l E -

• Secondary Containment en

," Refuel Floor Exhaust Duct - liigh $ 9 mr/hr 1,2,3 and

• 1 3tti 26 Radiation so .

" 1,2,3 and

• 26 Reactor Building Exhaust Shaft - 5 11 mr/hr 1 3

High Radiation ,

.I Of! gas vent Stack - liigh Radiation $ 1.5x10' cps 1,2,3 and a 1-' 3(Cl 26 RHR System Shutdown Cooling i

Reactor Vessel Pressure - High 5 135 psig 1,2,3 1 4 23 l I Y j' Reactor Water Cleanup j f

RWCU Differential Flow - High 5 40 gped 1,2,3 1 5 23 i

RWCU Area Temperature - High 5 130*F 1,2,3 1 5 23 RNCU Area Ventilation Differential A14*F8dl 1,2,3 1 5 23 Temperature - High Standby. Liquid Control System NA Note 1 4- Sl *l 23 Inittatton RWCU Area Near TIP Room 5 111.5'F 1,2,3 1 5 23 Ambient Temperature - High l/56LC sys%

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DAEC-1 Table 3.2-A (Continued) l l

ISOLATION ACTUATION INSTRUMENTATION l I

ACTION ACTION 20 - Be in at least HOT SHUTDOWN within 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> and in COLD SNUTDOWN within the next 24 hours.

ACTION 21 - Be in at least STARTUP with the associated isolation valves closed within 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> or be in at least HOT SHUTDOWN within 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> and in COLD SHUTDOWN within the next 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />.

ACTION 22 - Be in at least STARTUP within 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br />.

ACTION 23 - Close the affected system isolation valves within one hour and declare the af fected system inoperable.

ACTION 24 - Not Used ACTION 25 - Restore the manual initiation function to OPEAABLE status within 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> or close the affected system isolation valves l within the next hour and declare the affected system inoperable.

ACTION 26 - Establish SECONDARY CONTAINMENT INTEGRITY with the Standby Gas Tre'atment System operating.within one hour.

NOTES

• When handling irradiated fuel in the secondary containment and during CORE ALTERATIONS and operations with a potential for draining the reactor vessel.

• • When any turbine stop valve is greater than 90% open and/or when the key-locked bypass switch is in the NORM position.

(a) When a channel is placed in an inoperable status solely for performance of required surveillances, entry into associated Limiting conditions for Operation and required Actions may be delayed as follows: (1) for up to 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> for RWCU Differential Flow-High, RCIC Manual Initiation, HPCI Manual Initiations and (2) for up to 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> for the remaining Trip Functions provided the associated Trip Function maintains isolation capability.

(b) Operates Group 1 valves except Main Steam Isolation Valves. Also trips Mechanical Vacuum Pump which results in a subsequent isolation of the Mechanical vacuum Pump suction valves.

(c) Also starts the Standby Gas Treatment System.

(d) Actual setpoint shall be 14*F above the 100% opration ambient temperature conditions as determined by DAEC plant test procedure.'

(e) Closes MO-2701 and MO-2740 only.

(f) Requires system steam supply pressure-low coincident with drywell pressure-high to close HPCI/RCIC exhaust vacuum breaker valves.

(g) Manual isolation closes MO-2401 only, if RCIC initiation signal present.

(h) Manual isolation closes MO-2239 only, if HPCI initiation signal present.

(t) When the Standby Liquid Control System is required to be OPERABLE per Spectfacation 3.4.A.

(3) Within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> prior to the planned start of the hydrogen injection test with the reactor power at greater than 20% rated power, the normal full-power radiation background level and associated trip setpoints may be changed based on a calculated value of the radiation level expected during the test. The background radiation level and associated trip setpoints may be adjusted during the test program based on either calculations or measurements of actual radiation levels resulting from hydrogen injection. The background radiation level shall be determined and associated trip setpoints shall be set within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> of reestabitshing normal radiation levels after completion of the hydrogen anyection test or within 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> of establishing reactor power levels below 20% rated power, while these functions are required to be o rable.

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DAEC-1 emergency diesel generators. These trip levei settings were chosen to be high enough to prevent spunous actuation but low enough to initiate ECCS operation and priman system isolation so that post' accident cooling can be accomplished and the guidelines of 10 CFR 100 will not be ex'ceeded. For large breaks up to the complete circumferential break of a 22-inch recirculation line and with the trip setting given above, ECCS initiation and primary system isolation are initiated in time to meet the above criteria. Reference Sections 6.3 and 7.3 of the Updated FS AR.

The high dry,well pressure instrumentation is a diverse signal for malfunctions to the water level instrumentation and in addition to initiating ECCS, it causes isolation of Group 2 and 3 isolation valves. For the breaks discussed above, this instrumentation will generally initiate ECCS operation before the low-low-low water level instrumentation; thus the results given above are applicable here also. The water level instrumentation initiates protection for the full spectrum of loss-of-coolant accidents and causes isolation of all isolation valves except Group 6.

4 Venturis are provided in the main steam lines as a means of measuring steam flow nd also limiting the loss of mass inventory from the vessel during a steam line break acci The primary fun.ction of the instrumentation is to detect a break in the main steam li r the worst case accident, main s: cam line break outside the drywell, a t.ip setting of 140% o rated steam flow in conjunction with the flow limiters and consequently main steam line valve closure, limits the mass inventory loss such that fuel is not uncovered, fuel clad temperatures peak at approximately 1000'F and release of radioactivity to the environs is below 10 CFR 100 guidelines. Reference Subsection 15.6.5 of the Updated FSAR.

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Temperature monitoring instrumen 'on is provided in the main steam line tunnel and turbine building to detect leaks in this ar a. T 'ps are provided on this instrumentation and when exceeded, cause closure ofisolati n valves. The setting is 200 F for the main steam lineh detectQs. or large breaks, the high steam flow instrumentation is a backup to the temperature instrumentation.

High radiation monitors in the main steam line tunnel have been provided to detect gross fuel failure as in the control rod drop accident. A trip setting of 3 times normal full-power background is established to close the main steam line drain valves, recirculation loop sample valves, and trip the Mechanical Vacuum Pump. For changes in the Hydrogen Water Chemistry hyarogen irjection rate, the trip setpoint may be adjusted based on a calculated value of the radiation level expected. Hydrogen addition will result in an increase in the nitrogen (N-16) activity in the steam due to increased N-16 carryover in the main steam. Reference Subsection 15.4.7 of the Updated FSAR.

Pressure instrumentation is provided to close the main steam isolation valves in the RUN Mode when the main steam line pressure drops below 850 psig. The Reactor Pressure Vessel thermal transient due to an inadvertent opening of the turbine bypsss valves when not in the RUN Mode is less severe than the loss of feedwater analyzed in Subsection 15.6.3 of the Updated FSAR, therefore, closure of the Main Steam isolation valves for thermal transient protection when not in the RUN Mode is not required.

Pressure instrumentation provides a permissive function for opening RHR shutdown cooling isolation valves and provides automatic isolation of RHR shutdown cooling on increasing system pressure. This instrumentation provides assurance that the RHR piping transient pressure hmits are not exceeded during shutdown cooling operation.

The HPCI high flow and temperature instrumentation are provided to detect a break in the HPCI steam piping. Tripping of this instrumentation results in Amendment No. 109,12,142,193 3.2-44 RTS-276 M~# ,

02/95 b I 1

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Insert 'A There are four differential pressure instruments on each venturi, yielding 16 total instrument channels. Because of the number ofinstrument channels, they are arranged in a unique manner to achieve both electrical and spatial separation. One instrument channel from each of the four venturis, /A, one from each Main Steam Line (MSL), is combined into one logic channel. The four logic channels are then combined into the standard "one-out-of-two-twice" trip actuation arrangement. This allows one logic channel to be out-of-service and still provide isolation capability in the event of a steamline break in any MSL. The Allowed Outage Time (AOT) for required surveillance is applied at the instrument channel level, since the associated trip function and isolation capability are maintained via the companion logic channel. This is consistent with the " normal" trip arrangements with one instrument channel feeding each logic channel. Thus, a six-hour AOT isapplied to each instrument channel undergoing require, testing.

Insert B There are four resistance temperature detectors (RTDs) located along each MSL in the MSL tunnel area, yielding 16 total instrument channels. Because of the number ofinstrument channels, they are arranged in a unique manner to achieve both electrical and spatial separation. The four instrument channels from each MSL are combined into one logic channel. Eight instrument channels from two MSLs (2 logic channels) make up a trip system. To ensure spatial coverage is provided by these channels, a minimum of two instrument channels per MSL is required. Since the MSLs outside the MSL tunnel (Turbine Building) have fewer RTDs monitoring them (two RTDs per line), all eight instrument channels (four per trip system) are required to ensure spatial  ;

coverage. As with the differential pressure transmitters on the MSL venturis, the AOT for required surveillance is applied at the instrument channel level, since the trip function and isolation capability are maintained via the companion logic channel. Thus, a six-hour AOT is applied to each instrument channel undergoing required testing.

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RTS-282 3/95

RTS-282 Attachment 3 to NG-95-0934 Page1ofI SAFETY ASSESSMENT INTRODUCTION By letter dated March 28,1995, IES Utilities Inc. submitted a request for revision of the Technical Specifications (TS) for the Duane Arnold Energy Center (DAEC).

Amendment No.193 incorporated extended allowable out-of-service times and surveillance test intervals for various instrumentation and made other changes to improve clarity and provide consistency with the NRC Standard Technical Specifications (NUREG-0123) and the rest of the DAEC TS.

j During a review of maintenance activities planned on the Main Steam IIne Tunnel Temperature -

liigh trip switches, a question arose as to whether TS Table 3.2-A was inconsistent with the existing (original) plant design. Specifically, the TS MINIMUM OPERABLE CH ANNELS PER TRIP SYSTEM requirement is "2/line." It was not clear that with the physical design and the TS dermitions of channel and logic, the "2 instrument channels /line/ trip system" requirement could be met. Subsequent investigation determined that the existing design of the system is in conformance with the Architect / Engineer's design documentation and that the system has not been modified since original plant startup.

In addition, other line items in Table 3.2-A were identified that needed correction or clarification.

These changes to the TS improve clarity and consistency within the Table.

ASSESSMENT The changes do not alter the physical design or operation of the plant; they serve to describe more accurately and clearly the actual logic configurations and to improve consistency of the information in the Table. The existing logic designs are in accordance with the Architect / Engineer's design documentation and are configured to provide the intended function.

The clarifications do not impact the ability of any of the isolation logics to perform their intended functions, nor do they alrect any assumptions contained in the plant safety analysis.

The Bases changes support the above logic corrections and provide additional information to describe more clearly the logic configurations. Clarification of the Allowed Outage Times (AOTs) provides a more detailed description of how AOTs are applied to certain multiple instrument and logic channels. Since only one logic channel is removed from service at a time for testing and the trip ftmetion is maintained, conformance to the single failure criterion of the design bases (NEDO-10139, Compliance of Protection Systems to Industry Criteria: General Electric BWR Nuclear Steam Supply System, dated June 1970)is maintained. The application of the six l hour AOT to each instrument channel conforms to the analytical basis for the TS (NEDC-31677P-A, Technical Specification Improvement Analysis for BWR Isolation Actuation Instrumentation, dated July 1990).

Based upon the above infctmation, we have concluded that the proposed amendment to the operating license is acceptable.

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RTS-282 Attachment 4 to NG-95-0934 Page1of1 ENVIRONMENTAL CONSIDERATION 10 CFR Section 51.22(c)(9) identifies certain licensing and regulatory actions which are eligible for categorical exclusion from the requirement to perform an environmental assessment. A proposed amendment to an operating license for a facility requires no environmental assessment if operation of the facility in accordance with the proposed amendment would not: (1) involve a significant hazards consideration;(2) result in a significant change in the types or significant  ;

increase in the amounts of any efiluents that may be released offsite; and (3) result in a significant increase in individual or cumulative occupational radiation exposure. IES Utilities Inc. has reviewed this request and determined that the proposed amendment meets the eligibility criteria for categorical exclusion set forth in 10 CFR Section S t.22(c)(9). Pursuant to 10 CFR Section 51.22(b), no environmenta'l impac't statement or environmental assessmpnt needs to be prepared in '

connection with the issuance of the amendment. The basis for this determination follows:

Ilitsis The change meets the eligibility criteria for categorical exclusion set forth in 10 CFR Section 51.22(c)(9) for the following reasons:

1. As demonstrated in Attachment I to this letter, the proposed amendment does not involve a significant hazards consideration.

2. The proposed amendment includes changes which merely clarify existing logic configurations and improve consistency within TS Table 3.2-A and the associated TS Bases. No physical changes to the plant have occurred or will occur as a result of this change. The ability of the isolation logics to perform their intended functions are unalrected. Thus, there will be no significant change in the types or significant increase in the amounts of any ellluents that may be released offsite.

3. The proposed amendment includes changes which merely clarify existing logic configurations and improve consistency within TS Table 3.2-A and the associated TS Ilases. No physical changes to the plant have occurred or will occur as a result of this change. The ability of the isolation logics to perform their intended functions are unalrected. Thus, there will be no significant increase in either individual or cumulative occupational radiation exposure.

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