ML20237G833
| ML20237G833 | |
| Person / Time | |
|---|---|
| Site: | Hatch  |
| Issue date: | 08/31/1987 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML20237G824 | List: |
| References | |
| TAC-11158, NUDOCS 8709020428 | |
| Download: ML20237G833 (4) | |
Text
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!js k'i UNITED STATES NU': LEAR REGULATORY COMMISSION
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<y WASHINGTON, D. C. 20555 p., j SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION SUPPORTING AMENDMENT NO. 84 TO FACILITY OPERATING LICENSE NPF-5 GEORGIA POWER COMPANY OGLETHORPE POWER CORPORATION MUNICIPAL ELECTRIC AUTHORITY OF GEORGIA CITY OF DALTON, GEORGih EDWIN I. HATCH NUCLEAR PLANT, UNIT 2 DOCKET NO. 50-366 INTliODUCTION Section 3.7.8 of the Hatch Unit 2 Technical Specifications (TS) requires
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evaluation or shutdown of the unit whenever certain limit values of total settlement of Class 1 structures or of differential settlement between Class I structures are exceeded.
The TS were initially issueo on June 13, 1978, without the differential settlement limit values, but with a require-ment that the limit values be established and reported to the Comission by November 1, 1978.
By letter dated Dacember 1,1978, Georgia Power Company (the licensee) submitted proposed values for the differential settlement as l
part of an amendment request that would substantially revise the entire Section 3.7 8.
While this proposal was stiil under review by the staff, the licensee, by letter dated September 27, 1982 (Reference 1), requested that all its earlier submittals related to the proposed revision of Section 3.7.8 of the TS be withdrawn and requested an amendment that would delete Section 3.7.8 of the TS in its entirety.
This September 27, 1982 letter was followed by letters dated December 7, 1983, Nay 4, 1984, December 18, 1985, April 4, 1986 and January 5,1987, (References 2, 3, 4, 5 and 6, respectively), that discussed, clarified and augrented the September 27, 1982 request.
EVALUATION Any large, heavy structure can be expected to experience some settlement during and after construction as the weight of the structure causes con-solidation of the foundation material supporting the structure.
In general, the NRC staff has required licensees to commit to a program in the plant Final Safety Analysis Report (FSAR) to monitor the settlement of plant structures and to take corrective action if the settlement is excessive.
For Hatch Unit 2, in view of the excessive settlement problems that had i
been observed at the Midland plant and the fact that the Hatch plant is located on a deep soil foundation, absolute and differential settlement limits and the settlement monitoring program were made a part of the plant
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-(( TS. TS 3/4.7.0 was established out of concern that excessive absolute or differential settlement of plant structures could alter the geometric arrangement of the structures, resulting in a change to the plant design features described in response to 10 CFR 50.36(c)(4).
From the results of the settlement monitoring program provided by the licensee in the report subtritted with the January 5,1987 letter (Reference 6), the licensee con-cludes that the munitored plant structures are not now settling and have not been settling for at least the last eight years.
The data provided in the report indicated that:
(1) The settlement of the structures under consideration have essentially stopped and the measured total settlement for each structure is less than the predicted value. (2) no appreciab4 tilt h65 occurred in any of the structures anc in all cases the ratio measured differential settlement to the allowable differential settle 4 -
is no greater than 30 percent, and (3) for penetration differential settlements (between structure and soil) the ratio of the measured to t'e allowable is no greater than 59 percent.
Since the total absolute and differential settlements that have occurreo are well within the limits established by the TS and in view of the data which show that all settlement has now essentially stopped, the licensee proposes to delete TS 3/4.7.8.
However, to provide assurance that the building settlements have stabilized, and to assess the effects of any flood or earthquake on building settlements, the licensee proposes to con-duct a revised settlement monitoring program, which is to be implemented through a Plant Hatch operating procedure as follows:
(1) All building settlement benchmarks are to be surveyed once a year through 1988, once every two years through 1992, then once every five years thereafter except when an unusual meteorological or seismic event occurs, in whicn case the structures would be surveyed 1
as soon as possible.
1 (2) The scheduled surveys would be conducted at the same time of the year to avoid any fluctuations due to seasonal temperature.
(3) When the current survey reading differs from the previous one by more than 1/4-inch, a resurvey is required.
(4) The surveyed settlement values shall not exceed the predicted or allowable values.
If the total settlement of any structure reaches the predicted value, or the differential settlement across structures or between structure and soil exceeds 75 percent of the allowable values, a resolution of the problem by the licensee will be required.
The staff has reviewed the settlement survey data submitted by the licensee and concurs with the licensee's conclusion that the settlement of the plant structures has essentially stabilized.
in view cf the more then eight-year period with no essential change in settlement data, the staff concludes that there is now no further safety concern regarding additional plant settlement that mi ht affect the design features as described in response to 10 CFR 50.36(c (4).
Thus, we conclude that there is no need to continue the w_____________
., - - 1 settlement monitoring program prescribed by TS 3/4.7.8, ano that TS 3/4.7.P may be deleted. Further information regarding future settlement of plant i
structures will be obtained in accordance with tb? procedure proposed by the licensee.
ENVIRONMENTAL CONS 1DERATIONS The amendment changes a requirement with respect to installation or use of a facility component located within the restricted area as defined in 10 CFP Part 20. The staff has determined that the amendment' involves no significant increase in the amounts, and no significant change in the types, of any effluents thet may be released offsite, and that there is no significant increase in individual or cumulative occupational radiation exposure.
The Connission has previously issued a proposed finding that this amendment involves no significant hazards consideration and there has been no public comment on such finding. Accordingly, the Anendment meets the eligibility criteria for categorical exclusion set forth in 10 CFR 51.22(c)(9).
Pursuant to 10 CFR 51.22(b),'no environmental impact statement or environmental assessment need be prepared in connection with the issuance of the amendment.
CONCLUSION The Commission made proposed determinations that the amendment involves no significant hazards consideration which were published in the Federel Register (48 FR 52812) on November 22, 1983, and (52 FR 28376) on July 29, 1967, and consulted with the state of Georgia.
No public comments were received, and the state of Georgia did not have any comments.
We have concluded, based on the considerations discussed above, that:
(1) there is reasonable tssurance that the health and safety of the public will not be endangered by operation in the proposed manner, and (2) such activities will be conducted in compliance with the Commission's regulations, and the issuance of the amendment will not be inimical to the connon defense and security oc to the health and safety of the public.
. REFERENCES 1.
Letter from J. T. Beckham, GPC, to the Director, NRR, NRC, dated September 27, 1982.
2.
Letter from L. T. Gucwa, GPC, to J. F. Stolz, NRC, dated December 7,1983.
3.
Letter from L. T. Gucwa, GPC, to J. F. Stolz, NRC, dated May 4, 1984 4.
Letter from L. T. Gucwa, GPC, to D. Huller, NRC, dated December 18, 1985.
5.
Letter from L. T. Gucwa, GPC, to D. Muller, NRC, dated April 4,1986.
6.
Letter from L. T. Gucwa, GPC, to NRC, dated January 5, 1987.
Principal Contributors:
L. Crocker C. P. Tan
' Dated:
August 31, 1987 l
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DATED August 31, 1987 AMENDMENT NO. 84 TO FACILITY OPERATING LICENSE NPF-5, EDWIN I. HATCH, UNIT 2 dEWn'";
NRC F01 Local PDR PRC System PD#I1-3 Reading M. Duncan L. Crocker B. J. Youngblood D. Hagan T. Barnhart (4)
E. Butcher W. Jones ACRS(10)
OGC-Bethesda GPA/PA ARM /LSMB S. Varga
- 0. Lainas J. Partlow E. Jordan L. Reyes C. P. Tan
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