RBG-26562, Application for Amend to License NPF-47,revising Tech Spec to Delete Requirement to Perform Daily Channel Functional Tests on Rod Pattern Control Sys & Low & High Power Setpoints.Justifications Encl.Fee Paid

Application for Amend to License NPF-47,revising Tech Spec to Delete Requirement to Perform Daily Channel Functional Tests on Rod Pattern Control Sys & Low & High Power Setpoints.Justifications Encl.Fee Paid

ML20238E571
Person / Time
Site:	River Bend
Issue date:	09/04/1987
From:	Deddens J GULF STATES UTILITIES CO.
To:	NRC OFFICE OF ADMINISTRATION & RESOURCES MANAGEMENT (ARM)
Shared Package
ML20238E573	List: ML20238E579 RBG-26562, Application for Amend to License NPF-47,revising Tech Spec to Delete Requirement to Perform Daily Channel Functional Tests on Rod Pattern Control Sys & Low & High Power Setpoints.Justifications Encl.Fee Paid
References
RBG-26562, NUDOCS 8709150078
Download: ML20238E571 (8)

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. GULF ' STATES UTILITIES COMPANY -

RIVfR BEND STATION POST OFFLCE BOX 220' lit FRANCISVILLf. LOUISIANA 70775 A14E A CODE 604 636 60904 346 8051 September 4, 1987 RBG- 26562 l File Nos. G9.5, G9.8.9.6 i'

U.S.cNuclear. Regulatory Commission Document Control Desk

. Washington, D.C. 20555 Gentlemen:

River Bend Station.- Unit l' Docket No. 50-458 Gulf States Utilities (GSU) hereby files'an application for an amendment to the' River Bend Station Unit 1 Technical, Specifications, Appendix A to' Facility: Operating License NPF-47, pursuant to 10C(h50.90. This application is filed to delete.'.the ' requirement to perform the -daily -

Channel Functional Test' on the Rod Pattern Control. System, Low Power-Setpoint'and'High Power Setpoint. The Attachment includss the proposed

' revisions and justifications ito the' River Bend Station Technical

' Specifications.

Pursuant to 10CFR170.12, GSU has enclosed a check in the amount of' one-hundred and ' fifty dollars ($150.00) for. the license amendment application fee. Your prompt attention to this application- is appreciated.

Sincerely, ff "

J. C. Deddens Senior Vice President River ~ Bend Nuclear' Group JCD/ .AS/ch rm Attachment J

8709150078 8709042 pDR ADOCK 05000458

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.s UNITED STATES OF AMERICA-NUCLEAR REGULATORY COMMISSION STATE'OF LOUISIANA )'

-PARISH OF WEST FELICIANA )

In the Matter of ) Docket No. 50-458 50-459 GULF STATES UTILITIES COMPANY -)

(River Bend Station, Unit.1)

AFFIDAVIT J. C. Deddens, being duly sworn, states that he is a Senior Vice President of Gulf States Utilities Company; that he is. ' authorized on the part of said company to sign and file with the Nuclear Regulatory Commission the documents attached hereto; and that'all such documents are true and correct to the best of his knowledge, information and belief.

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J. C[Deddens Subscribed and sworn to before me, a Notar Public in ,

and for the State and Parish above named, this - day of Senlernbr- , 19 W.

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. i Jni s .N w E tt D g!Joan W. Middlebrooks Notary Public in and for West Feliciana Parish, Louisiana l My Commission is for Life.

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Mr. Robert D.' Martin, Regional Administrator l U.S. Nuclear Regulatory Commission l~ . Region IV i ..

611 Ryan. Plaza Drive, Suite 1000 Arlington, TX .76011 NRC Senior Resident Inspector P.O. Box 1051 St. Francisv111e, LA 70775'

.Mr. William H. Spell, Administrator l Nuclear' Energy Division 11 Louisiana Department of-Environmental Quality P.O.-Box 14690 Baton Rouge, LA 70898

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' ATTACHMENT GULF' STATES UTILITIES COMPANY RIVER BEND STATION DOCKET'50-458/ LICENSE NO. NPF . CONTROL ROD BLOCK INSTRUMENTATION LICENSING DOCUMENT. INVOLVED: TECHNICAL SPECIFICATIONS l

. ITEMS: Table 4.3.6-1 PAGES: 3/4 3-63 3-64 REASON FOR REQUEST

Technical Specification 3/4.3.6, Control Rod Block Instrumentation,-

Table4.3.6-1, Control Rod Block Instrumentation Surveillance Requirements.'for. the Rod Pattern Control System, Items 1.a Low Power Setpoint, and;1.b, High Power Setpoint, currently require a Channel

. Functional. Test ;be performed on-the trip units prior to startup (S/U),

daily (D) and monthly (M) . This proposed change would perform the test prior to startup and' monthly but delete the requirements to' perform the Channel Functional Test daily and modify the associated footnotes accordingly. This change is being requested due to the excessive surveillance frequency and hardship as compared to similar trip units which are all ' tested 'on ~ a monthly basis per the River Bend Station Technical Specifications.

DESCRIPTION The intent of these surveillance requirements is to demonstrate the OPERABILITY of the Low Power Setpoint.(LPSP) and the.High Power Setpoint

-(HPSP). The purpose of the LPSP is. to initiate Rod Pattern- Control.

~ System (RPCS) interlocks on decreasing power and Rod Withdrawal Limiter Lc (RWL) interlocks on increasing power. The purpose of the RPCS is to minimize'~the -individual rod worths to ensure the peak enthalpy of 280 .

cal /g will not be exceeded in the event of a control rod drop accident. 'l As. shown by analysis, this is not a concern at reactor powers greater than 20% rated thermal power, and therefore, the RPCS does not place any pattern restrictions on control rod movement above the LPSP. The i purpose of the RWL is to prevent fuel damage in the event of erroneous 1 rod withdrawal from locations of high power density during power I operation above the LPSP. The purpose of the HPSP is to provide the RWL l with an interlock to enforce more stringent limitations on control rod movement at greater than 70% rated thermal power.

Technical Specification 3/4.1.4.2 requires the RPCS to be OPERABLE with the reactor in Modes 1 and 2. The RPCS is demonstrated OPERABLE by l verifying that the rod pattern controller functions when thermal power ]

.is less than the LPSP by selecting and attempting to move an inhibited l control rod. The RPCS is also demonstrated OPERABLE by verifying that the rod withdrawal limiter functions when thermal power is greater than i, .or equal to the LPSP by selecting and attempting to move a restricted control rod in excess of the allowable distance.

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k The River Bend Station-(RBS) Technical Specifications (Notes e and d of Table 4.3.6-1) presently require the Channel Functional Test to be performed daily or prior to control rod movement, and daily as power is increased above the RPCS Low Fower Setpoint or decreased below the LPSP.

l Another Channel Functional Test is performed at least once per 31 days while operation continues above the LPSP. These functional tests are performed on Rosemount trip units identical to trip units located throughout the plant which receive Channel Functional Tests monthly per their, applicable Technical Specification Surveillance. Requirements.

These trip units are subjected to a 30 fold increase in surveillance test intervals as compared to identical trip units in, for instance, the Reactor Protection System (Technical Specification 3/4.3.1) without an identified corresponding increase in reliability.

1 At RBS there are approximately 135 Surveillance Test Procedures (STP's) which perform Channel Functional Tests on Rosemount trip units. Of these, only the LPSP and HPSP STP's require a Channel Functional Test on a frequency less than once every 31 days. Since RBS has been performing this daily surveillance, there have been no failures of this STP related to these trip units. Additionally, a review of the NPRDS data base revealed no reported failures that could have been detected by this required daily Channel Functional Test. Therefore, it is concluded that the Channel Functional Tests prior to startup and monthly thereafter will adequately ensure the reliability of this system.

The requirement to perform the HPSP surveillance when decreasing power below the LPSP serves no purpose. Since the HPSP is not required to be OPERABLE until greater than 70% rated thermal power, it is appropriate to change the HPSP applicability to Operational Condition 1, greater than the LPSP.

The proposed change will significantly reduce the manpower associated with performance of this surveillance and will provide operational consistency, flexibility and clarity of surveillance requirements while meeting the intent of the surveillance.

SIGNIFICANT HAZARDS CONSIDERATION As discussed in 10CFR50.92, the following discussions are provided to the NRC Staff in support of "no significant hazards considerations".

1. No significant increase in the probability or the consequences of an accident previously evaluated results from this change because:

There have been no reported failures of this surveillance due to failures related to these trip units since RBS has been performing this daily Channel Functional Test. Additionally, a review of the ,

NPRDS data base revealed no reported failures that could have been detected by this required daily Channel Functional Test. Therefore,

'l the reliability of the system is adequately ensured by the  !

performance of the Channel Functional Tests prior to startup and  !

monthly thereafter. The change to the applicability of the HPSP is l based on actual system design as was the intent. This change does

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not involve a design change or physical change to the plant, and therefore, does not increase the probability of a control rod drop or rod withdrawal accident. No other safety analyses as discussed in TSAR Chapters 6 and 15 would be changed.

Thus, there is no increase in the probability or consequences of any accident previously evaluated.

2. This change would not create the possibility of a new or different kind of accident from any accident previously evaluated because:

This change is a clarification of intent. The reliability of the system is not changed by performance of the Channel Functional Tests prior to startup and monthly thereafter as shown by the absence of any failures of this STP at RBS during this daily performance. The NPRDS data identifed no reported failures that could have been detected by this required daily Channel Functional Test.

Additionally, this change does not involve a design change or l physical change and therefore, does not change the system design, function, or operation as previously described in the RBS FSAR.

Thus, no new or different accident scenario is introduced by this revised frequency of surveillance and clarification of surveillance intent.

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3. This change would not involve a significant reduction in the margin l of safety because:

1 There have been no reported failures of this surveillance due to failures related to these trip units since RBS has been performing this daily Channel Functional Test. Therefore, the reliability of the system is adequately ensured by the performance of the Channel Functional Tests prior to startup and monthly thereafter. The clarification of applicability is consistent with the actual design.

Additionally, the Technical Specification Bases do not define a margin of safety as applied to the daily Surveillance Requirement.

Thus, the margin of salety is not significantly reduced.

Since the proposed amendment is consistent with current design and adequately maintains the reliability of the RPCS, the proposed amendment does not increase the probability or consequences of any previously evaluated accidents, does not create the possibility of a new or different type of accident, and does not involve a significant reduction in a margin of safety. Therefore, GSU proposes that no significant hazards considerations are involved.

REVISED TECHNICAL SPECIFICATION The requested revision is provided in the Enclosure.

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SCHEDULE FOR ATTAINING COMPLIANCE q

As indicated-above, River Bend Station is currently in compliance with -

the applicable Technical Specifications.

NOTIFICATION OF STATE PERSONNEL A copy of this amendment application has been provided to the State of Louisiana, Department of Environmental Quality - Nuclear Energy Division. , t ENVIRONMENTAL IMPACT APPRAISAL Revision of this Technical Specification does not result in an environmental impact beyond that previously analyzed. Therefore, approval of this amendment does not result in a significant environmental impact nor does it change any previous environmental _'

impact statements for River Bend Station.

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