ML20205R143

Safety Evaluation Supporting Amend 104 to License DPR-40

ML20205R143
Person / Time
Site:	Fort Calhoun
Issue date:	03/26/1987
From:	Office of Nuclear Reactor Regulation
To:
Shared Package
ML20205R107	List: ML20205R101 ML20205R138 ML20205R143
References
TAC-63437, NUDOCS 8704060235
Download: ML20205R143 (3)

Text

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Eter UNITED STATES 8 o NUCLEAR REGULATORY COMMISSION y, I wasumoron,o. c. noses

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. SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION RELATED TO AMENDMENT NO.104 TO FACILITY OPERATING LICENSE NO. DPR-40 OMAHA PUBLIC POWER DISTRICT FORT CALHOUN STATION, UNIT NO. 1 DOCKET NO. 50-285 INTROCUCTION I

! By letter dated November 5, 1986 Omaha Public Power District (OPPD) submitted l

j an application for a license amendment that would modify Section 3 of the Technical Specifications relative to the surveillance criteria for steam j generator tube inspections. The purpose of the proposed amendment is twofold:

I first to provide better clarity and labeling of the Surveillance Section concerning steam generator tube examinations and second, to change acceptance criteria designation from a numerical to a percentage basis.

DISCUSSION In the Technical Specifications for Fort Calhoun Station, Unit No.1, testing

' of steam generator tubes falls under Section 3.3, " Reactor Coolant System, Steam Generator Tubes, and Other Components Subject to ASME XI Boiler and ,

Pressure Vessel Code Inspection and Testing Surveillance." The title is misleading in that it appears that the Steam Generator Tube Inspections are under the scope of ASME Section XI Boiler and Pressure Vessel Code. The intent has never been to place steam generator tube examinations within the scope of ASME Section XI inspection. The intent was, rather, to perform the i

examinations in accordance with Regulatory Guide 1.83, Revision 1, as stated in the " Basis" of Section 3.3 of the Technical Specifications. 'Thus, the steam generator tube examination portion is proposed to be moved from Section 3.3 to a new section dedicated specifically to steam generator tube examiriation. '

In the new designation as Technical Specification 3.17, additional changes are being made to convert the criteria for Sample Selection and Inspection Results from fixed numerical criteria to comparable percentages. The purpose of the change is to accommodate steam generator tube inspection where the sample size has been increased from the minimum size required by the Technical Specification and Regulatory commitments.

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. The criteria for eddy current inspection of the steam generator tubes listed in Technical Specification 3.17(2) conform to the requirements of Regulatory Guide 1.83, Revision 1, C.4, C.5 and C.6 and deviations approved by the

Commission in the Safety Evaluation supporting Amendment No. 46 to Facility d'

Operating License No. DPR-40. When the sample size of tubes to be inspected is the minimum sample size in each sample inspection, the classification of' inspection results as Categories C-1, C-f, and.C-3 in the present Technical Specifications specifies the acceptable limits for degraded and defective tubes in terms of the fixed number of tubes. The numbers specified represent a realistically conservative conversion of percentage limits given in Regulatory Guide 1.83 when applied to the minimum sample size of 3 percent of the total tubes in the steam generators. However, when the sample size of tubes inspected is increased above the minimum number of tub'es in each sample inspection, the fixed numbers associated with the degraded and defective tubes specified for each category becomes unrealistically conservative.

1 EVALUATION i

The proposed changes only affect the organization of the Technical Specifications concerning steam generator tube. inspections and not the content of these sections. The acceptance criteria, formerly designated in terms of the number of tubes inspected, have been changed to percentage of tubes in each sample inspection. There are no changes in equipment or surveillance methodology. The change affects only those sample inspections

where the sample size exceeds the minimum size specified in Table 3-13.

l The results of increased sample size will be evaluated by the same criteria used to evaluate the results of the minimum size. When sample size is-increased from the minimum size, reliability of the inspection is increased over that of the minimum requirements. The use of fixed numbers associated with the degraded and defective tubes specified for each category becomes unrealistically conservative for large sample sizes. The proposed percentage basis will maintain the same acceptance criteria regardless of the sample size. An inconsistency, which appears to be an omission on the part of the licensee, was observed in the proposed Table 3-13. The minimum sample sizes in columns 1, 3 and 5 of the table should be designated as percentagep to be consistent with the proposed changes elsewhere.

The proposed changes do not alter the content of the Technical Specifications l or the probability of finding defective or degraded tubes. These changes '

also satisfy the requirements of Regulatory Guide 1.83 and other regulatory  ;

requirements and are, therefore, acceptable. We have requested the licensee i to submit a proposed license amendment to modify Table 3-13 to show sample l size in percentage rather than numerical values. The proposed Table 3-13 is 4 l acceptable in its present form because the numerical values are conservative

! relative to sample size calculated by percentage in conformance with the Standard Technical Specifications.

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1 ENVIRONMENTAL CONSIDERATION This amendment relates to changes in recordkeeping, reporting, or administrative procedures or requirements. Accordingly, the amendment 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 nedd be prepared in connection with the issuance of the amendment.

CONCLUSION We have concluded, based on the considerations discussed above, that-(1) there is reasonable assurance 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 common defense and security or to the health and safety of the public.

Date: March 26,1987 Principal Contributor:

J. Rajan i

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