ML20070U663

Application for Amends to Licenses NPF-11 & NPF-18,changing Tech Specs to Eliminate Use of Rod Sequence Control Sys & Reduce Low Power Setpoint Initiation for Rod Worth Minimizer to 10% of Rated Power Per NEDE-24011-P-A-9-US

ML20070U663
Person / Time
Site:	LaSalle
Issue date:	04/02/1991
From:	Piet P COMMONWEALTH EDISON CO.
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
Shared Package
ML20069M900	List: ML20070U663 ML20070U664
References
NUDOCS 9104090240
Download: ML20070U663 (5)

Text

{{#Wiki_filter:i 8 0 Ccmmenwealth Edison 10 CFR 50.90 1400 Opub Place 4 Downers Grove, Ulinois 60515 April 2,1991 U.S. Nuclear Regulatory Conunission Attn: Document Control Desk Washington, D.C. 20555

Subject:

LaSalle County Station Units 1 and 2 Application for Amendment to Facility Operating Licenses NPF il and NPF-18, Appendix A, Technical Specifications: Deletion of Rod Sequence Control System and Lowering of Rod Worth Minimizer Setpoint NRCDocket NoL50-313 atd50:3M _

Reference:

(a) A.C. Thadani Letter to LS Chamley dated December 27,1987 ( Amendment 17 to GE Docutuent NEDE-240 J 1-P- A-9-US, " General Electric Standard Application for Reactor Fuel") Gentlemen: Pursuant to 10 CFR 50.90, Commonweatrh Edison (CECO) proposes to amend Appendix A, Technical Specifications o'i acility Operating Licenses NPF 1I and NPF-18. The proposed amendment requests the following changes: 1) the elimination of the required use of the Rod Sequence Control System (RSCS) and 2) the reduction of the Low Power Setpoint (LPSP) initiation for the turnoff of the Rod Worth Minimizer (RWM) from twenty (20) percent of rated power to ten (10) percent of rated power, This proposed amendment request is subdivided as follows:

1. Attachment A gives a description and safety analysis of the proposed changes in this amendment.

2. Attachment f) includes the nuuked-up Technical Specifications pages with l

the requested changes indicated.

3. Attachment C describes CECO's evaluation perfonned in accordance with 10 CFR 50.92 (c), which confimis that no significant hazards cor, sideration is involved.

4. Attachment D provides the Environmental Assessment.

l This proposed amendment has been reviewed and approved by CECO On-Site and Off-Site Review in accordance with Contmonwealth Edison procedures.

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4 4 U.S. Nuclear Regulatory Commission April 2,1991 To the best of my knowledge and belief, the statements contained within are true i and correct, in some respect these statements are not based on my personal knowledge, but obtained infonnation furnished by other Conunonwealth Edison employees, contractor employees, and consultants. Such infonnation has been reviewed in accordance with company practice, and I believe it to be reliable. Commonwealth Edison is notifying the State of Illinois of this application for amendment by transmitting a copy of this letter and its attachments to the designated , l state official.  ! 4 Please direct any questions you may have concerning this submittal to this office. l Very truly yours, i m s ( -

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                                                                      '  Peter L. Piet Nuclear Licensing Administrator l

i Attachments: l l A. Description of Safety Analysis of the Proposed Changes , D. Marked Up Technical Specification Pages l C. Evaluation of Significant llazards Considerations D. Environmental Assessment i l i l i I cc: A.B. Davis - Regional Administrator, Rill l Senior Resident inspector - LSCS ' John liickman - NRR, Project Manager Office of Nuclear Facility Safety - IDNS PLP:lw , ZNLD807/2-3 Signed before me this M day of __INfM'I ,1991. ( u. .

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      ',                                                   NITACllMENTA DESCRIPTION DES AFETLANALYSIS.OET11E PROPOSED CilANGES 1

Description l This amendment request addresses the following proposed revisions to the LaSalle County Station Units One and Two Technical Specifications: 1) the elimination of the required use uf the Rod Sequence Control Systern (RSCS) and 2) the reduction of the Low Power Setpoint (LPSP) initiation for the turnoff of the Rod Worth Minimizer (RWM) from twenty (20) percent of full power to ten (10) percent. Iluses.cf thefroposed_ Changes On December 27,1987 the NRC approved Amendment 17 to NEDE-240ll P-A-9 US," General Electric Standard Application for Reactor Fuel", GESTAR 11(Reference a). Approval of this amendment allowed ti.e lowering of the setpoint for turnoff of the Rod Worth Minimizer (RWM) to 10 percent of full power from the current setting of 20 percent. This approval was based on existing calculations which demonstrated that no significant Rod Drop Accident (RDA) could occur above 10 percent power. The 20 percent limit was originally required as an extreme bound because of the existing uncertainties in the analysis. Additionally, the amendment allowed elimination of the required use of the Rod Sequence Control System (RSCS). Analysis had shorn that because of improved studies and calculations of the RDA, Banked Position Withdrawal Sequence (HPWS) control rod patterns, and improved RWM operability, the RWM could 6 consider-d an acceptable system of rod pattern control, mitigating the consequences of the RDA. It was therefore detennined that the RSCS was not needed and operation without it was allowed. Reference (a) stated that licensee's that referenced the GH topical report in support of their license applications could do so to the extent specified and under the limitations delineated in the report and the associated NRC evaluation. These amendment requests would require that the proposed Tech Specs for the RWM require use of the RWM to an extent which would minimize substitution of a second operator for the RWM and thus provide a strong incentive to maintain and improve that system. It' also required that utilities requesting RSCS removalieview - procedures and provide a discussion of their review regarding independence and q, 4 . control for second y operator verification of rod moves. Finally, it reconunended mat the rod patterns used for these reactors be at least equivalent to HPWS patterns. In referencing the General Electric Arnendment, the above mentioned requirements were addressed as they apply to LaSalle County Station. InL0a0?/4

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 ',                                                         -   ItWhUmproXements To minimize substitution of a second operator, action staternent b, of the RWM Technical Specification (3.1.4.1) is being changed from:
                  "The provisicas of Specification 3.0.4. are not applicable" to, "The provisions of Specifications 3.0.4. are not applicable, with the exception that control rod withdrawal for reactor startup shall not begin with the RWM inoperable."

This will prevent unit startups from commencing if the RWM is not operable. Current Station procedures provide a strong incentive for ensuring that the RWM is operable. LOP-RW 01, " Rod Worth Minimizer Initialization and Operation", states that if it is I necessary to bypass the RWM due to inoperability, a Qualified Nuclear Engineer v:ill be notified, and approval from the Assistant Superintendent of Operations will be rece.ived prior to continuing rod movement. ! In an effort to improve the RWM system, LaSalle has installed a new system, an Enhanced Ro/ ' ' orth Minimizer (EllRWM). The EHRWM corrects four major problems of the original system. These problems were as follows: 1) system reliability;

2) system maintenance; 3) scanning speed; 4) poor operator interface methodology.

Modem microcornputer technology has increased the reliability of the syntein and made l maintenance easier by using commonly available printed circuit cards and two independent computer systems for hardware redundancy. Faster scanning time is accom alished by replacmg ok'er hardware through the use of a coler graphic CRT ii .: control room that is easily operated by a touch screen. Most importtmtly, the EHRWM l enforces BPWS constraints at all times. l l To assure that the sewnd operator provides an effective and independent i verification during the infrequent occasions that the EHRWM is inoperable, a review of I applicable station procedures was perfonned. The following eight (8) procedures will be revised to include specific guidelines on how second operator verification must be performed:

1. LOP-RW-01 " Rod Worth Minimizer Initialization and Operation".

2. LAP-100-13, "Controt D.~' 'quence Package Preparation, Review, and Implementation".

3. LAP-100-30, "Indeoendem verification".

4. LGP-1-1, "Nonnal Unit Startup"

5. L6P-1-2, " Unit Startup to Hot Standby".

6. LGP-1-3, " Unit Startup from liot Standby to Power Operation".

7. LGP42-1 " Normal Unit Shutdown".

3. LGP-2-2, " Unit Shutdown from Operation to Hot Standby",

The guidelines will provide a directive for second verification enforcing the operator to request permission before moving the rod, followed by the second verifier granting permission. Likewise, completion of the move will be announced by the operator and acknowledged by the second verifier. This will ensure a complete independent check of rod me /ements. ZtiLC907 /5

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4 3 PhmLOperation_withfropond. Changes in addition to the above mentioned procedure changes which enforce independent verification, a number of procedural and setpoint changes will be made to eliminate the required use of the RSCS and to lovar the setpoint for turnoff of the RWM from 20 percent power to 10 percent power. Instrument setpoint changes and drawing changes requests (DCRs) will be perfomied a. / Sat the LPSP for the RWM will be lowered to 10 percent power and the Low Powei fdann Point (LPAP) for the RWM lowered to 25 percent power. Site procedure LIP-FW-503 (603), " Unit 1 (2) Main Steam Line Flow Calibration", will be revised to incorporate these setpoint changes. Numerous site prneedures have references to the LPSP, such as: "... low power setpoint, i.e.,20 pen,ent power", or ".. 20 percen' power". These references will be changed to: ... the low rowc2 setpoint (as defined by Tech. Spac. 3.1.4,1, Rod Worth Minimizer)" !.Rewise, a Scftware Wivity Request (SAR) will be performed to revise the EHRWM so that ali error messages and conmumds that appear on the graphic CRT scree i'l state "LPSP" and not "20 percent power".

                         ,nclut, ion, the preceding sections have addressed the bases to eliminate the re    aa.         of the RSCS and lowering of the setpoint for turnoff of the RWM from 20 pe: i              r to 10 percent power and thereby incorporate Amendment 17 of GESTAR
        .for x   e a4       at LaSalle County Station Units 1 and 2.

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