ML20050A886

Suppl to Final Deficiency Rept Re Rosemount 510 Du Trip Units Drawing More Current than Specified,Initially Reported 790904.Power Supplies Being Replaced.Also Reportable Per Part 21

ML20050A886
Person / Time
Site:	Grand Gulf
Issue date:	03/22/1982
From:	Mcgaughy J MISSISSIPPI POWER & LIGHT CO.
To:	James O'Reilly NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II)
References
REF-PT21-82 10CFR-050.55E, 10CFR-50.55E, AECM-82-44, NUDOCS 8204020365
Download: ML20050A886 (5)

Text

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1 MISSISSIPPI POWER & LIGHT COMPANY Helping Build Mississippi i M P. O. B O X 10 4 0. J A C K S O N MI S SIS SIP PI 3 9 2 0 5

>s J AMES P. McGAUGHY, JR March 22, 1982 i A5$lST ANT VKE Pfat SIDE NY g Of fice of Inspection & Enforcement (")

U. S. Nuclear Regulatory Commission ,

Region II 101 Marietta Street, N.W.

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Atlanta, Georgia 30303 ._ -

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At tent ion: Mr. J. P. 'Reilly, Regional Administrator N5 1

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SUBJECT:

Grand Gul n Units 1 and .

ut grgta Docke t Nos. 50-416/417 File 0260/15525/15526 PRD-7 9/12, 10CFR21 Supplement to Final Report, Rosemount 510 DU Trip Units AECM-82/44 .

References:

1) AECM-79/110, 10/2/79

2) AECM-80/56, 3/21/80 On September 4,1979, Mississippi Power & Light Company notified Mr. V.

Brownlee, of your of fice, of a Potentially Reportable Deficiency (PRD) at the Grand Gulf Nuclear Station (GGNS) construction site. The deficiency concerns Rosemount 510 DU Trip Units drawing more current than was originally speci-fled, causing the associated power supplies to be inadequate.

We had previously submitted our Final Report on this deficiency under the provisions of 10CFR50.55(e). We have since determined that this deficiency is also reportable under the provisions of 10CFR21. Details are provided in our attached Supplemental Final Report.

Our previous report, AECM-80/56, 3/21/80, contains a typographical error.

It states that our Constructor tracked this deficiency with Management Correc-tive Action Report (MCAR)-51. This should have been MCAR-53.

Yours truly,

. P. McGaughy, Jr.

KDS:dr ATTACIMENT cc: See page 2 1CIAi, copy 8204020365 - --

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Mr. J. P. O'Reilly AECM-82/44 NRC Page 2 cc: Mr. N. L. Stampley Mr. R. B. McGehee Mr. T. B. Conner Mr. Richard C. DeYoung, Director Office of Inspection & Enforcement U. S. Nuclear Regulatory Commission Washington, n.C. 20555 Mr. G. B. Taylor South Miss. Electric Power Association P. O. Box 1589 Itattiesburg, MS 39401

l Attachment to AECM-82/44 Page 1 of 3 SUPPLEMENT TO FINAL REPORT FOR PRD-79/21

1. Name and address of the individual . .. informing the commission:

J. P. McGaughy , Jr.

Assistant Vice President, Nuclea r P.O. Box 1640 Jackson, Mississippi 39205 Notification of Part 21 applicability made to Mr. J. P. O'Reilly, NRC, Region II by letter AECM-82/44, March 22,1982.

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

Grand Gulf Nuclear Station (GGNS) Units 1 and 2 Port Gibson, Mississippi 39150

3. Identification of the firm . . . supplying the basic component which .. .

contains a deficiency:

Supplied to Grand Gulf by Bechtel Power Corporation, Gaith.3rsburg, Ma ryland. Bechtel obtained these components from Rosemount, Inc.,

Eden Prairie, Minnesota.

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

A. Description of the Deficiency The maximum current drain for the Rosemount Model 510 DU master and slave trip units exceeds the original specified value.

Actual current requirements may exceed the original specified value for two reasons. The current required by the gross failure circuitry was not considered by Rosemount in the original specifica-tion. The gross failure circuitry requirements include the gross f ailure LED current, the silicon controlled rectifier (SCR) biasing current, and the trip output LED current. In addition, current requirements increased because of design changes to the trip units in question. The design changes pertain to the operating require-ments for the 555 integrated circuit which is part of the negative 4.7 volt power supply.

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.- Attachment to AECM-82/44 )

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j B. Analysis of Safety Implications I

A review was performed by our Constructor of the power sources for all the safety-related Rosemount Model 510 DU master and slave trip units to determine if the larger current drains would adversely af fect the operation of the systems to which they are designated.

It has been determined that power supplies P41-JY-K600 A & B for Units 1 and 2 (Bailey Model 808094003) are not large enough to handle the larger maximum current drains specified by Rosemount.

All other power sources have adequate capacity to handle the larger current drains.

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

Mississippi Power and Light received information_of the deficiency on a September 4, 1979. We reported the deficiency to Mr. V. Brownlee of your office as a Potentially Reportable Deficiency on that date. Since that date MP&L has filed two (2) reports to inform the Commission of the progress and status of the evaluation of this deficiency. A Final Report under the provisions of 10CFR50.55(e) was submitted March 21, 1980. An evaluation for Part 21 has been completed and the MP&L " Responsible Of ficer", Mr. J. P. McGaughy, Jr. , will be notified when he returns to his office.

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

The Rosemount Mode? 510 DU Trip Units are located at Grand Gulf Nuclear Station in Unit 1 and Unit 2.

We do not have knowledge of the location of defective equipment other than at GGNS.

7. The corrective action which has been taken ... the name of the individual

. . . reponsible for the action; and the length of time that has been . . .

taken to complete the action.

A. Corrective Actions Taken The inadequate power supplies are being replaced.

B. Responsible Individual C . B . Roge rs , J r .

Site Manager Mississippi Power and Light Company t

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.' .- Attachment to AECM-82/44 Page 3 of 3 C. length of Time to Complete Actions Mississippi Power & Light received information of the deficiency on September 4,1979. Bechtel issued MCAR-53 on that date to track this deficiency. Corrective actions are in the process of being completed. All work on Unit I has been completed. Unit II will be completed prior to Unit II fuel load. The work is being tracked on MCAR-5 3.

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.

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