Text

Proposed Tech Specs Surveillance Frequencies for Rod Block Instrument Sys
	ML20070H332
Person / Time
Site:	Duane Arnold
Issue date:	07/12/1994
From:	; IES UTILITIES INC., (FORMERLY IOWA ELECTRIC LIGHT
To:	;
Shared Package
ML20070H294	List: ML20070H332; NG-94-2353, Requests for TS Change (RTS-266) to License DPR-49,modifying Surveillancene Frequencies During Startup for Rod Block Instruments;
References
	NUDOCS 9407210215
	Download: ML20070H332 (6)
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t l

RTS-266 to l

NG-94-2353 Page1of1 PROPOSED CHANGE RTS-266 TO THE DUANE ARNOLD ENERGY CENTER TECHNICAL SPECIFICATIONS The holders oflicense DPR-49 for the Duane Arnold Energy Center propose to amend Appendix A (Technical Specifications) to said license by deleting certain current pages and replacing them l

with the attached, new pages. The List of Affected Pages is given below.

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LIST OF AFFECTED PAGES i

l 3.2-23 i

3.2-24

SUMMARY

OF CHANGES:

The following list of proposed changes is in the order that the changes appear in the Technical Specifications.

Page Description of Changes 3.2-23 Revise the Table 4.2-C requirement to perform a Channel Functional l

Test on the Rod Block Monitor (RBM) system Upscale, Downscale and l

Inoperative trips from "within 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months prior to Startup" (referenced as existing footnote "b") to " Prior to exceeding 30% RATED THERMAL l

POWER" (referenced as new footnote "d"). The allowance to not perform the test if performed within the previous 7 days is retained, as is the reference to existing footnote "c."

Revise the Table 4.2-C requirement to perform a Channel Functional Test on the Average Power Range Monitor (APRM) system Flow-biased Upscale and Downscale rod block trips from "within 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months prior to Startup" (referenced as existing footnote "b") to "within 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months after entering RUN and prior to exceeding 25% RTP" (referenced as new footnote "e"). The allowance to not perform the test if performed within the previous 7 days is retained.

Revise the Table 4.2-C requirement to perform a Channel Functional Test on the Reactor Recirculation System recirculation flow Upscale, Inoperative and Comparator rod block trips from "within 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months prior to Startup" (referenced as existing footnote "b") to "within 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months after entering RUN and prior to exceeding 25% RTP" (referenced as new footnote "e"). The allowance to not perform the test if performed within the previous 7 days is retained.

3.2-24 Add new footnotes "d" and "e," which correspond to the new references in the Table, noted above.

9407210215 940712 PDR ADOCK 05000331 P

PDR

Tabl e 4. 2--c Collil3OL ROD HLOCK INSTRUl1ENTATIOri SUFVEILLANCE REOUIREMENTS OPERATIONAL g

CONDITIONS 3

CIIANNEL FOR WHICil 3

CHANNEL FUNCTIONAL CHANNEL SURVEILLANCE TRIP FUNCTION ~

CHECK TEST CALI B RATION

REQUIRED

.m S R(d)G) f Rod Block Monitor

/

g Upscale (Power Referenced)

D S / U**", Q

5/R SA la Downscale D

S / U "*", Q~'

S/U.

s SA 1*

.g Inoperative NA S / U**",

NA la tra APRM y

is Flow Biased Upscale D

S U*',

Q I

Upscale in Startup D

S U',Q 3

-8)

Q 2,5 Inoperative NA S U*',Q 8

NA 1,2,5 w

Downscale D

U',

Q.

1 Intermediate Rance Monitors Detector not full in NA S / U'*, W R

2,5 Upscale D

S / U*', W Prior to Startup or Controlled Shutdown 2,5 Inor*rative NA S / U+', W NA 2,5 N

Downscale D

S / U*', W Prior to Startup or Controlled Shutdown 2,5 N

Source Rance Monitors 4

Detector not full in NA S/U*,W R

2,5 Upscale D

S / U+', W Prior to Startup or Controlled Shutdown 2,5 Inoperative NA S / U+', W NA 2,5 Downscale D

S/U**,W Prior to Startup or Controlled Snutdown 2,5 Scram Discharoe volume Water Level-High NA Q

R 1,2,5**

' Recirculation Flow S[tl l

SA 1

Upscale NA S/U*,Q

/ g(O lg)# y NA 1

I; Inoperative NA S / U*' Q Comparator NA S / U*',

Q SA 1

Reactor Mode Switch -

NA R

NA 3,4 Shutdown Position 2

m.

1 DAEC-1 Table 4.2-C (Continued)

CONTROL ROD BLOCIC INSTRUMENTATION SURVEILLANCE REOUIREMENTS NOTES (a)

Neutron detectors may be excluded from CHANNEL CALIBRATION.

(b)

Within 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months prior to startup, if not performed within the previous 7 days.

(c)

Includes reactor manual control multiplexing system input.

M With THERMAL POWER a 30% of RATED THERMAL POWER.

With more than.one control red withdrawn.

Not applicable to control rods removed or withdrawn per Specification 3.9.A.

(d) ? dor lo execdin3 30"/.RmD1{EPJ4AL?0WER if rd prformed wiNdn the previoe'Idays.

3 (e) WNhin 2%e af4cr cdennytlN W por a e<ue& 25Porkren wm4LPOWER ifyd 3

3 p rk m eA ui h 4ie paviv s ~+ kys.

3 Amendment No. 64.123.743.150.193 3.2-24

RTS-266 to NG-94-2353 l

Page1of2 S_AFETY ASSESSMENT By letter dated July 12,1994, IES Utilities Inc. submitted a request for revision of the Technical Specifications (TS) for the Duane Arnold Energy Center (DAEC). The proposed amendment requests revisions to the Surveillance Requirements (SR) for certain Rod Block Instrument systems. Specifically, the requirement to perform Channel Functional Tests prior to STARTUP for the Rod Block Monitor (RBM), Flow-biased l

Average Power Range Menitor (APRM) and Recirculation Flow instruments is being revised to allow the SRs to be performed aller the Reactor is in the RUN mode, but prior to when each system is assumed to function in the plant safety analysis. Performance of the SRs " prior to STARTUP" requires the extensive use ofjumpers and relay blocks. The proposed changes in the SRs ensure that the function will be demonstrated to be OPERABLE prior to when they are required to be OPERABLE, but without the need for thejumpers and relay blocks.

Assessmeni RE 3 ?S.OCK MONITOR SYSTEM 1

For the RBM system, the proposed change to the SR frequency merely revises that requirement to match the existing mode requirement for OPERABILITY in TS Table 3.2-l C. As OPERABILITY will be demonstrated prior to entering the operating condition where the system is required to be OPERABLE, the proposed revision to the SR.

frequency is found to be ecceptable.

AVERAGE POWER RANGE MONITOR SYSTEM The proposed change to the SR frequency for the APRM Flow-Biased Rod Block Channel Functional Test to allow the SR to be performed after the reactor enters the RUN mode, but prior to exceeding 25% RTP, will ensure that the system is demonstrated to be l

OPERABLE prior to reaching a power level where the Safety Limit Minimum Critical Power Ratio (SLMCPR) could be challenged,2 l

The purpose of TS-required surveillances is to validate OPERABILITY. In almost all cases, the SR confirms that the equipment is, in fact, OPERABLE and no cor:cctive actions are needed to restore OPERABILITY, in this case, the APRM Rod Blocks in RUN mode utilize circuitry that is common in the APRM system to the STARTUP mode Rod Blocks; the only difference is the circuit cards that compare the incoming APRM l

i signal to the rod block setpoint. However, both setpoint circuit cards (STARTUP and RUN) are calibrated quarterly. Thus, a high probability exists that the RUN mode Rod i

Blocks are OPERABLE, even though the proposed change allows the SRs for RUN moue 1 DAEC Updated Final Safety Analysis Report (UFSAR) Section 15.4.2 2 DAEC License Amendment #120 l

j RTS-266 to NG-94-2353 Page 2 of 2 to be delayed until afler entering the RUN mode, as the SRs for the STARTUP mode Rod

~ locks would have been satisfactorily performed and confirmed the OPERABILITY of B

the APRM circuits common to both modes.

In addition, extensive use ofjumpers and relay blocks will be avoided by performing the SR in the RUN mode, thus eliminating the potential for either the inadvertant actuation or disabling of an Engineered Safety Feature (ESF). During the performance of this SR, the reactor mode switch is placed in the RUN position, although the plant is actually in a Cold -

Shutdown condition. In order to preclude ESF actuations that are not germane to this' Channel Functional Test, such as the Main Steamline Isolation Valve Closure with l

Reactor Pressure U850 psig (mode switch in RUN), jumpers and relay blocks are used in those logic trains. Although the probability is small, the potential does exist for either a jumper or relay block to become dislodged during the test, allowing an inadvertant ESF actuation, or a failure to remove thejumper or relay block at the completion of the SR could occur, thereby disabling the ESF logic until its next scheduled SR is performed.-

Therefore, the proposed change will enhance safety by eliminating the use of these jumpers and relay blocks.

Consequently, based upon the above, we conclude that the proposed change to the APRM Flow-biased Rod Block SR is acceptable.

RECIRCULATION SYSTEM ROD BLOCKS i

The proposed change in the SR frequency for the Recirculation system Rod Blocks is the same as those proposed for the APRM system. As the sole purpose of the Recirculation

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system rod blocks is to ensure that an invalid signal for reactor recirculation flow is not input into the flow-biased APRM rod block circuits, validation of the OPERABILITY of l

these rod blocks prior to exceeding 25% RTP is not critical, based upon thejustification i

given above that the APRM system Rod Blocks themselves, are not critical below 25%

RTP.

1 Consequently, based upon the above evaluation, we find that the proposed changes in the SR frequency for the Recirculation Flow Rod Blocks to be acceptable.

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RTS-266 to NG-94-2353 Page1 of1 ENVIRONMENTAL CONSIDER ATION 10 CFR Part 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 l

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 an increase in individual or cumulative j

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 Part 51.22(c)(9). Pursuant to 10 CFR Part 51.22(b), no environmentalimpact statement or environmental assessment needs to be prepared in connection with the issuance of the amendment. The basis for this determination follows:

]

Basis The change meets the eligibility criteria for categorical exclusion set forth in 10 CFR Part 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 revises the requirement to perform Channel Functional Tests prior to Startup for the Rod Block Monitor (RBM), Flow-biased Average Power Range Monitor (APRM) and Recirculation Flow Rod Block instrumentation. As this instrumentation is not part of those systems that control or monitor plant efiluents, there will be no increase in either the types or amounts of efiluents that may be released offsite as a result of this proposed change.

3.

The proposed Amendment revises the requirement to perform Channel Functional Tests prior to Startup for the RBM, Flow-biased APRM and Recirculation Flow l

Rod Block instrumentation. As this instrumentation is located in an area of the plant with a low radiation field and surveillances of this instrumentation during l

Startup are already specified in the TS, there will be no increase in either individual or cumulative occupational exposure as a result of this proposed change.

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ML20070H332

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