ML20137G029

Forwards Safety Evaluation Permitting Delay for Up to 5 Yrs for Final Projection of Max post-const Groundwater Level & Resolution of Exceedance of Design Basis Groundwater Level at Dewatering Well 8,per Util 840309,850214 & 0325 Ltrs

ML20137G029
Person / Time
Site:	Grand Gulf
Issue date:	08/19/1985
From:	Novak T Office of Nuclear Reactor Regulation
To:	Richard J MISSISSIPPI POWER & LIGHT CO.
Shared Package
ML20137G033	List: ML20137G029 ML20137G048
References
TAC-M54498, NUDOCS 8508270150
Download: ML20137G029 (3)

Text

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August 19, 1985 DISIN60 TION:

gkytket Nos. 50-416/417 NRC PDR local PDR' Docket Nos.: 50-416 PRC System and 50-417 LB #4 r/f

< EAdensam MDuncan LKintner Mr. Jackson B. Richard GStaley Senior Vice President, Nuclear Attorney, OELD Mississippi Power and light Company JPartlow P.O. Box 23054 EJordan Jackson, Mississippi 39205 BGrimes ACRS (16)

Dear Mr. Richard:

-Sukject: Grand Gulf. Nuclear Station, Units. I and 2 - High Groundwater level By letter dated March 0, 1984, Mississippi Power & Light Company (MPal) reported that-the water level in Dewatering Well No. 8 (one of fourteen monitoring and dewatering wells) exceeded the design basis groundwater level of 109.0 feet mean sea level (msl) by up to 1.2 feet during January to June 1983. MP&l. requested a review of this condition by the staff.

MP&L retained Bechtel Corporation to determine the cause of the exceedance.

By letter dated February 14, 1985, MP&L submitted the Bechtel report and additional information requested by the staff regarding the effect of the

-exceedance on safety-related structures and equipment, precipitation data.

models to calculate groundwater level and the dewatering systems for Units 1 and 2. By letter dated March 25, 1985, MP&L reported that the level in Dewatering Well No. 8 exceeded the design basis groundwater elevation by 0.1. feet on February 28, 1985 due to a clogged screen for the dewatering well pump. After the pump was repaired the level dropped to 2.4 feet below the design basis level.

'The NRC staff has completed its review of the letters dated March 9, 1984, February 14, 1985 and March 25, 1985. The staff's safety evaluation is enclosed. Based on its review of licensee's analysis of groundwater levels up to 114.5 feet msl, the staff concludes that the integrity of safety-related facilities was not compromised by the reported exceedance of the design basis groundwater level. The staff also concludes that the probable reasons for the high water level in Dewatering Well No. 8 were above average rainfall, incomplete backfilling and clay seal for Unit 2 structures, and the location of the well in the circulating water pipe trench which may function as a collector sump. Considering the licensee's commitment to retain dewatering capability for Units 1 and 2 until completion of Unit _2 8508270150 850819 PDR ADOCK 05000416 P PDR

Mr. Jackson B. Richard construction and backfilling, and the low probability of occurrence of rainfall necessary to exceed a groundwater level of 109 msl, the staff con-cludes that final projection of the maximum post-construction groundwater level and resolution of exceedance to the design basis groundwater level can be de-layed for up to 5 years, but no later than December 1990. If a final resolution of this issue is delayed beyond 1990, licensee is requested to provide, at that time, a status report and schedule for submittal of a final report. In the interim, any occurrences of groundwater levels in the power block area that exceed the design basis level (109.0 feet msl) should be reported to the NRC.

In addition, the updated Final Safety Analysis Report (FSAR) to be submitted in December 1985 and annually thereafter, should include: pertinent data for monitoring well Nos. 7 and 8 in FSAR Table 2.4-29; all regional and perched aquifer groundwater level readings, and; the monthly rainfall measurements from the meteorological tower.

Sincerely, Originct Signed BY Thomas M. iiovak Thomas M. Novak, Assistant Director for licensing Division of Licensing

Enclosure:

As stated cc: See next page l

• PREVIOUSLY CONCURRED LB#4:DL

• LKintner:kab LA:DL:lB #4

• MDuncan EHEB:DE

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Mr. Jackson B. Richard Mississippi Power & Light Company Grand Gulf Nuclear Staiton ec:

Robert B. McGehee, Esquire The Honorable William J. Guste, Jr.

Wise, Carter, Child, Steen and Caraway Attorney General P.O. Box 651 Department of Justice Jackson, Mississippi 39205 State of Louisiana Baton Rouge, Louisiana 70804 Nicholas S. Reynolds, Esquire Bishop, Libeman, Cook, Purcell Mr. Oliver D. Kingsley, Jr.

and Reynolds Vice President, Nuclear Operations 1200 17th Street, N.W. Mississippi Power & Light Company Washington, D. C. 20036 P.O. Box 23054 Jackson, Mississippi 39205 Mr. Ralph T. Lally Manager of Quality Assurance Office of the Governor Middle South Services, Inc. State of Mississippi P.O. Box 61000 Jackson, Mississippi 39201 New Orleans, Louisiana 70161 Attorney General Mr. Larry F. Dale, Director Gartin Building Nuclear Licensing and Safety Jackson, Mississippi 39205 Mississippi Power & Light Company P.O. Box 23054 Mr. Jack McMillan, Director Jackson, Mississippi 39205 Solid Waste Mississippi State Board of Health Mr. R. W. Jackson, Project Engineer 880 Lakeland Bechtel Power Corporation Jackson, Mississippi 39206 15740 Shady Grove Road Gaithersburg, Maryland 20760 Alton B. Cobb, M.D.

State Health Officer Mr. Ross C. Butcher -

State Board of Health Senior Resident Inspector P.O. Box 1700 U.S. Nuclear Regulatory Commission Jackson, Mississippi 39205 Route 2, Box 399

-. Port Gibson, Mississippi 39150 President Claiborne County Board of Supervisors Regional Administrator, Region II Port Gibson, Mississippi 39150 U.S. Nuclear Regulatory Commission, 101 Marietta Street, N.W., Suite 2900 Atlanta, Georgia 30323 Mr. J. E. Cross, General Manager Grand Gulf Nuclear Station Mississippi Power & Light Company P.O. Box 756 Port Gibson, Mississippi 39150