ULNRC-03131, Informs That Util Will Implement Current Order Timing Mod & Current Order Surveillance Test,As Described in Listed WOG Documents During Refuel 7 (Mar-May 1995) in Response to NRC 941215 RAI Re GL 93-04

Informs That Util Will Implement Current Order Timing Mod & Current Order Surveillance Test,As Described in Listed WOG Documents During Refuel 7 (Mar-May 1995) in Response to NRC 941215 RAI Re GL 93-04

ML20078B082
Person / Time
Site:	Callaway
Issue date:	01/19/1995
From:	Schnell D UNION ELECTRIC CO.
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
GL-93-04, GL-93-4, TAC-M86837, ULNRC-03131, ULNRC-3131, NUDOCS 9501250260
Download: ML20078B082 (5)

Text

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I901 Chouteau henue

, Post Offim Box 149 St tows. M:ssoun~ 63166 r

. 314 554 2650 [

Uuron January 19, 1995 ton,S,*e;-ll,,

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P3 U.S. Nuclear Regulatory Commission ATTN: Document Control Desk Mail Station F1-137 .

Washington, D.C. 20555 ,

ULNRC-03131 ,

Gentlemen: TAC NO. M86837 '

DOCKET NUMBER 50-483 CALLAWAY PLANT ROD CONTROL SYSTEM FAILURE AND WITHDRAWAL OF ROD CLUSTER CONTROL ASSEKBLIES, 10 CFR 50. 54 (f)

References:

1. NRC Generic Letter 93-04 dated l June 21, 1993

2. ULNRC-2832 dated August 5, 1993  !

3. ULNRC-2857 dated September 17, 1993  ;

4. NRC Request for Additional Information letter dated December 15, 1994 Pursuant to the requirements of 10 CFR 50.54 (f) , the NRC issued Reference 1 to all licensees .

with the Westinghouse Rod Control System (except Haddam Neck) for action and to all other licensees for information. References 2 and 3 provided Union Electric's 45-day and 90-day responses, respectively, as required by Reference 1.

In Reference 4, the NRC noted their approval, by letter dated November 10, 1994 to the Westinghouse Owners Group (WOG), of the following documents:

(1) WCAP-13864, Rev. 1, " Rod Control System Evaluation Program," (2) Westinghouse Technical Bulletin NSD-TB-94-05-RO, " Rod Control-CRDM Timing Change," and (3) "WOG Recommended Rod Control System Surveillance Test." Reference 4 also requested a commitment to implement the current order timing modification and the new current order surveillance test, as described in the approved WOG documents above, prior to startup from the next refueling outage. In response,. Union Electric will implement the following during Refuel 7 (March-May 1995):

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1. The current order, timing modification defined  !

! in. Westinghouse Technical Bulletin NSD-TB 05-R0 will be completed by, repositioning diodes on the Westinghouse Solid State Rod .

Control System Logic Cabinet Slave Cycler i Decoder Cards. This will implement a revised ,

Westinghouse standard timing applicable txa j all models of rod drive mechanisms in the ,

L-106 family.  ;

The post-modification acceptance: tests (slave cycler logic traces with the reactor trip i l

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breakers open to verify that the.tf, ming i sequences have been properly revised and current traces with the trip breakers closed-to verify that proper rod motion occurs) will be performed in general conformance with the  ;

test outline in Attachment 2 of the Technical Bulletin. The current traces will be taken in  !

i conjunction with rod drop time testing and j will record three steps of insertion from the >

j fully withdrawn position and then three steps l

of withdrawal for all of the control'and f shutdown rods. '

While the intent is to take current traces l for each of the 53 rods, obtaining this information for one rod in each group is  ;

sufficient to ensure that the modification was implemented correctly. If unanticipated ,

problems in testing prevent taking current traces for all 53 rods, the outage will not be extended if current traces for at least l one rod in each group have been taken.

2. Prior to startup from every refueling outage after Refuel 7, a current order surveillance i test will be performed to obtain current traces for one rod in each group of control and shutdown banks for three steps of insertion and three steps of withdrawal in conjunction with rod drop time testing. This will be similar to Test C discussed in the "WOG Recommended Rod Control System Surveillance Test". No slave cycler logic traces, as taken during the post-modification testing discussed above, will be routinely taken as part of this surveillance. As stated in the introduction to Test C in the "WOG Recommended Rod Control System Surveillance Test", measuring the current profile to one rod in each group is

- U.S. Nuclear Regulatory Commission

. Page 3 sufficient to verify the current timing and l regulation and satisfy the requirement to  :

detect single failures in the Rod Control  !

System that would corrupt the current orders without affecting rod movement.

The NRC will be notified in_ writing after we have implemented the current order timing modification i

.and the current order surveillance test. Should you  !

have any questions on the above, please contact us. l l

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Very.truly yours, I

l Donald F. Schnell  ;

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i STATE OF MISSOURI )  !

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CITY OF ST. LOUIS )  !

Donald.F. Schnell, of lawful age, being first duly sworn i upon oath says that he is Senior Vice President-Nuclear.and an officer of Union Electric Company; that he has read the foregoing document and knows the content thereof; that he has executed the same for and on behalf of said company with full. power and authority to'do so; and that the facts therein stated are true and correct to the best of his  ;

knowledge, information and belief.

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l By Donald F.' Schnell Senior Vice President i Nuclear SUBSCRIBED and sworn to before me this /8 day of (3ds//101- ,W

/ V /99 A w - O. h BARBA A J. A NOTARY PUBUC-STATE OF MISSOURI MY COMMISSION EXPIRES APRIL 22,1997 l ST. LOUIS COUNTY.

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l cc:. T. A. Baxter, Esq.

Shaw, Pittman, Potts & Trowbridge 2300 N. Street, N.W.

Washington, D.C. 20037 l M. H. Fletcher Professional Nuclear Consulting, Inc. .

18225-A Flower Hill Way I Gaithersburg, MD 20879-5334 L. Robert Greger Chief, Reactor Project Branch 1 U.S. Nucleal f:Julatory Commission Region III 801 WarrenvilAe Road Lisle, IL 60532-4351 Bruce Bartlett Callaway Resident Office U.S. Regulatory Commission RR$1 Steedman, MO 65077 L. R. Whartor; (2) i Office of Nuciear Reactor Regulation i U.S. Nuclear Regulatory Commission .

1 White Flint, North, Mail Stop 13E21 11555 Rockville Pike .

Rockville, MD 20852-2738  !

Manager, Electric Department Missouri Public Service Commission ,

P.O. Box 360 Jefferson City, MO 65102 ,

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