AECM-84-0148, Final Deficiency Rept Re Incorrect Operation of Div I & II Diesel Generator Load Shedding Sequencing Sys Panels. Initially Reported on 830921.Circuit Cards & Card Racks Returned for Mod.Reinstallation Expected by 840427

Final Deficiency Rept Re Incorrect Operation of Div I & II Diesel Generator Load Shedding Sequencing Sys Panels. Initially Reported on 830921.Circuit Cards & Card Racks Returned for Mod.Reinstallation Expected by 840427

ML20087H461
Person / Time
Site:	Grand Gulf
Issue date:	03/15/1984
From:	Mcgaughy J MISSISSIPPI POWER & LIGHT CO.
To:	James O'Reilly NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II)
References
REF-PT21-84 AECM-84-0148, AECM-84-148, NUDOCS 8403210041
Download: ML20087H461 (5)

Text

a E MISSISSIPPI POWER & LIGHT COMPANY Helping Build Mississippi P. O. B O X 164 0, J KSON, MISSISSIPPI 39205 March 15, 1984 J AMES P. McGAUGHY, JR.

vice rassiormt U. S. Nuclear Regulatory Canmission Region II 101 Marietta Street, N.W.

Suite 2900 Atlanta, Georgia 30303 Attention: Mr. J. P. O'Reilly, Regional Administrator

SUBJECT:

Grand Gulf Nuclear Station Unit s 1 and 2 Docket No. 50-416/417 License No. NPF-13 File 0260/15525/15526/16694.4 PRD-83/13, Final Report for Unit 2, Load Shedding and Sequencing System Panels AECM-84/0148 Reference AECM-83/0609,9/21/83 On September 21, 1983, Mississippi Power & Light Company notified Ms. L.

Watson, of your office, of a Reportable Deficiency at the Grand Gulf Nuclear Station (GGNS). The deficiency concerns the incorrect operation of the Division I and II diesel generator load shedding and sequencing system panels with the automatic test feature on-line.

MP&L had previously determined that this deficiency is reportable under the provisions of 10CFR21 for Unit 1 and has since determined that it is reportable under the provisions of 10CFR50.55(e) for Unit 2. All details are contained in our attached Final Report. This report was originally due on March 1, 1984, howe'Jer a two week extension was granted on that date by Mr.

Caudies Julian.

Yours truly, J. P. McGaughy, Jr.

(DS:dr ATTACIE'.ENT cc: See page 2 8403210041 840315 -

DR ADOCK 05000 OFF1G R c'y',-

Member Middle South Utilities System d12 '1 j

Mr. J. P. O'Reilly AECM-84/0148 NRC Page 2 cc: Mr. J. B. Richard Mr. R. B. McGehee Mr. T. B. Conner Mr. Richard C. DeYoung, Director Of fice of Inspection & Enforcement U. S. Nuclear Regulatory Commission

'4ashington, D.C. 20555 Mr. G. B. Taylor South Miss. Electric Power Association P. O. Box 1589 Hattiesburg, MS 39401

m.,

bs; .\

% 8 Attachment to AECM-84/0148 Page 1 of 3 V'

FINAL REPORT FOR UNIT 2 -

1. , Name and address ; of the individual . . . informing the commission

J. P. McGaughy, Jr.

~

Vice-President, Nuclear -

P.O. Box 1640

."- ' Jackson,_ Mississippi 39205 Notification of-Part 21 reportability for Unit 1 made to Mr. J. P.

O'Reilly, NRC,- Region -II by letter AECM-83/0609, Sept ember 21, 1983.

~ ' -Notification of 10CFR50.55(e) reportability for Unit 2 made to Ms. L.

n Watson,' NRC, Region. II by telephone on 10/14/83.

' This deficiency was also reported under 10CFR21 by Vitro Laboratories to the NRC, Washington, D. C., in'their letter dated August 19, 1983.

1 2.. Identification of- the facility . .. which . .. contains a deficiency:

Grand ' Gulf Nuclear Station (GGNS)-Units 1 and 2

- Port Gibson, Mississippi ' 39150 110CFR21. is not applicable for Unit 2 as the Load ' Shedding and Sequencing panels have not been turned over to MP&L. However, the deficiency is reportable under 10CFR50.55(e) for Unit,2.

J

3. - Identification of the fira . .. supplying . the basic component which . . .

, 'contains a~ deficiency:

The' Load Shedding and Sequencing panels were manufactured by Vitro

. Laboratories, Silvar Spring,' Maryland ~and supplied to Grand Gulf" bylBechtel Power' Corporation, Gaithersburg, Maryland.

4

4. Nature of the deficiency ... and the safety hazard which ... could be created by such a deficiency ...:

-A. Description of the Deficiency During the performance of the 18 month surveillance testing of the diesel generators, it was discovered that the Division I and II

Load Shedding and Sequencing. Panels,1H22-P331 and P332, do not always respond .as designed to a LOCA signal while the panels are in the Auto Test Mode. The Load Shedding 'and Sequencing System

' Auto; Test Mode, which is on-line for normal system operation, sinputs high frequency signala and decodes output signals to deter-

, mine if the panel logic is capable of functioning. The deficiency involves a situation where _ the high frequency auto test signal

~

[' - does_ not get blocked upon receipt of a LOCA signal, and the LSS J

^-'

-,,-a,,- ..,,v. ,-.,nn - - - - . ,- . . . . , . - - - ~ . ~ - - - , - , .---,-n..

r' 1 "J . ,.

At tachment to AECM-84/0148 Page 2 of 3 I

panel responds.to the accident at a speed determined by the high frequency clock. Thus the shed and sequence output relays do not have time to energize. This incorrect operation only occurs when the LOCA signal is input to the system coincident and synchronous with the test pulse and does not occur on the receipt of a loss of power; signal or when the Auto Test Mode is off.

B.- Analysis of Safety Implications

. Division I and II ECCS Pumps would not be sequenced back on the ESF bus and therefore would not aut o-start , if required.

Other' loads would act shed or sequence at the right time.

5.- The date on which the information of such deficiency ... was obtained.

Mississippi Power & Light received information of the deficiency on July 23, 1983. - We reported the deficiency to Ms. L. Watson, of your office, as a Reportable Deficiency for. Unit 1 on September- 21, 1983. An evaluation for Part 21 was completed for Unit I and the MP&L

" Responsible Of ficer," Mr. J. P. McGaughy, Jr. , was notified.

Notification of reportability under 10CFR50.55(e) for Unit 2 was made to Ms. L. Watson on October 14, 1983.

6. In the case of the basic component ... the number and location of all such components.

There are two (2) LSS panels on each Unit at Grand Gulf for a total of

'four (4). The location of other panels which have similar design deficiencies was reported to the NRC, Washington, D. C., by Vitro Laboratories in their letter of August 19, 1983.

7. The corrective action which has been taken . .. the name of the individual ... responsible for the action; and the length of time that has been . . . taken to complete the action.

-A.- Corrective Actions Taken 1 A design modification was provided and installed by Vitro under DCP-83/0398,as a field- change to the Unit 1 LSS panels. Retests of the panels were satisfactory.

For Unit 2, the ' printed circuit cards and card racks were returned to the manufacturer for modification to install the reset feature.. The modification was completed as required.

B. Responsibic Individual Unit 1 Unit 2

'J. E. Cross T. H. Cloninger

. Plant Manager Unit 2 Project Manager Mississippi Power & Light Co. Mississippi Power & Light Co.

i

-^o;*; y ,

t-Attachment to AECM-84/0148 Page 3 of 3 r

C. Isnath of Time to Complete Actions Corrective actions for Unit 1 are complete. The reinstallation and final checkout for Unit 2 is expected to be compiered by April 27,.1984.

8. Any . advice related to the deficiency ... that has been, is being, or will be given to purchasers or licensees:

As 'the deficiency did,not originate with MP&L, we have no advice to offer.

W

'e k

I k

, - - * - ---,-v---- vy-, y y - - -,--r-I -

t mw , - , , , . - , . - a.--- -w,---w a9--- w r%--- ,, 7---g-