ML19347E414

Final Deficiency Rept Re Effects of Loss of Site Power on Rod Position Indication & Neutron Monitoring,Initially Reported on 800317.Typographical Error Noted in Previous Rept.Deficiency Determined Not Reportable Per 10CFR50.55e

ML19347E414
Person / Time
Site:	Grand Gulf
Issue date:	04/21/1981
From:	Mcgaughy J, Mcgoughy J MISSISSIPPI POWER & LIGHT CO.
To:	James O'Reilly NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II)
References
10CFR-050.55E, 10CFR-50.55E, AECM-81-145, NUDOCS 8104270297
Download: ML19347E414 (3)

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Edhlikklids Helping Build Alississippi P. O. B O X 16 4 0, J A C K S O N MIS SIS SIP PI 3 9 2 0 5 April 21, 1981 J

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Office of Inspection & Enforcement ,9/

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Region 11 'f, p ISg7 C 101 Marietta Street, N.W. ,

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Atlanta, Georgia 30303 ,

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Attention: Mr. J. P. O'Reilly, Director

SUBJECT:

Grand Gulf Nuclear Stat".on Units 1 and 2 Docket Nos. 50-416/417 File 0260/15525/15526 PRD-80/04, Final Report, Effects of Loss of Site Power on Rod Position Indication and Neutron Monitoring AECM-81/145

References:

1) AECM-80/66, 4/3/80

2) AECM-80/105, 5/21/80

3) AECM-80/163, 7/23/80

4) AECM-80/318, 12/30/80 i

On March 17, 1980, Mississippi Power & Likht discussed the subject

! condition with Mr. F. Cantrell of your office. Based on this discussion, MP&L agreed to process this matter as a potentially reportable deficiency. This deficiency pertains to the Loss of Site Power (LOSP) accident and its l

attendant effects on Rod Position Information System (RPIS) and Neutron Monitoring System (NMS).

l We regret the typographical error in the date in the last paragraph of Reference 4, which should have read "1981". Our final report is attached, in which we have concluded that this condition is not reportable under l 10CFR50.55(e).

Yours truly, l

-f l J. P. Mc y,'Jr. 304.5 EWC/JCC:st Attachment /

cc: See page 2 //' 7 S

8104 a 7 0 f-9

~ Member Middle South Utilities System

i Mr. J. P. O'Reilly AECM-81/145 Page 2 NRC cc: Mr. N. L. Stampley

! Mr. R. B. McGehee Mr. T. B. Conner Mr. Victor Stello, Director Office of Inspection & Enforcement U. S. Nuclear Regulatory Commission Washington, D.C. 20555 .

Mr. G. B. Taylor South Miss. Electric Power Association P. O. Box 1589 Hattiesburg, MS 39401 l

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Attachment to AECM-81/145 Page 1 of 1 FINAL REPORT FOR PRD-80/04 I. Description of the Deficiency This deficiency pertains to the loss of certain instrumentation that occurs as the result of a Loss of Site Power (LOSP) event.

As a result of the LOSP, power is lost to the Reactor Protection System (RPS) motor-generator (M/G) sets. These M/G sets supply power to the RPS buses which in turn supply power to several safety related loads, including the Nuclear Monitoring System (NHS) and Rod Control and Information System (RCIS). Thus, immediately following the LOSP event, the operator does not have those two instrumentation systems to provide core neutron level and rod position.

II. Analysis of Safety Implications The analysis of the LOSP event for GGNS is presented in Chapter 15 of the GGNS FSAR. The ahalysis concludes that no unacceptable consequences occur. In addition to the Chapter 15 analysis, separate investigations were. conducted into this matter by General Electric and Mississippi Power & Light.

' Neither the NMS nor the RCIS are required to provide safety functions a

following the LOSP. The safety function of primary concern is

! accomplished by the control rod drive hydraulic system. On sensing loss of power a full reactor scram is initiated, inserting all control rods.

Since the safety of plant operations is not compromised by the above described deficiency, it is concluded that this concern is not reportable unde- 10CFR50.55(e).

III. Corrective Actions Taken While it is MP&L's position that this deficiency is not reportable, the power supply configuration in question is considered to be operationally undesirable. Evaluations are currently underway to address this concern. Descriptions of all actions taken will be available on request.

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