B12649, Responds to NRC 870818 Request for Addl Info Re Util 870601 Application for Amend to License DPR-61,providing long-term Acceptance Criteria for Steam Generator Tubes W/Defects Located in Rolled Region.Flaw Identification Discussed

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Responds to NRC 870818 Request for Addl Info Re Util 870601 Application for Amend to License DPR-61,providing long-term Acceptance Criteria for Steam Generator Tubes W/Defects Located in Rolled Region.Flaw Identification Discussed
ML20237G643
Person / Time
Site: Haddam Neck File:Connecticut Yankee Atomic Power Co icon.png
Issue date: 08/27/1987
From: Mroczka E
CONNECTICUT YANKEE ATOMIC POWER CO., NORTHEAST UTILITIES
To:
NRC OFFICE OF ADMINISTRATION & RESOURCES MANAGEMENT (ARM)
References
B12649, NUDOCS 8709020346
Download: ML20237G643 (4)


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I l esm =ves ut=w"*' P.O. BOX 270 k k sC$~5cb.,,, HARTFORD. CONNECTICUT 06141-0270 J mus%ca . ,.u, um, (203. 665-5000 August 27,1987 l

Docket No. 50-2'3 i B12649 f i

U. S. Nuclear Regulatory Commission Attn: Document Control Desk Washington, D. C. 20555

3. Mroczka letter to U. S. NRC Document Control Desk,

Reference:

1.

"Haddam Neck Plant Proposed Revision to Technical Specifications - Steam Generators," dated June 1,1987.

Gentlemen:

Haddam Neck Plant Additional Information Proposed Revision to Technical Specifications Steam Generators in Reference (1), Connecticut Yankee Atomic Power Company (CYAPCO) submitted a license amendment request to change the Technical Specifications of the Haddam Neck Plant. The proposed changes will provide a long-term acceptance criteria for the steam generator tubes with defects located in the rolled region and update the basis for this criteria.

As requested by the NRC Staff during a telephone conversation on August 18, 1987, CYAPCO hereby submits the following additional information on our proposed changes to the Technical Specifications. The NRC Staff requested information on 1) assurance that roll-region flaws within the "F*" zone are identified by inspections, and 2) adequacy of future roll-region eddy current test (ECT) inspection programs.

ROLL REGIONAL FLAW IDENTIFICATION The ECT inspection program used during the present Haddam Neck Plant refueling outage includes the following features:

1. A "MlZ-18" data acquisition system, and multifrequency data analysis with a "DDA-4" data analysi:, system is being used.
2. Full length, bobbin-probe tests of 100 percent of the tubes in all four steam generators (SG) are underway as required by Technical Specifications.
3. A special probe was developed and is being used for optimum elevation rietermination of flaws relative to the F* zone.

8709020346 DR 870927 p ADOCK 05000213 PDR

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U. S. Nuclear Regulatory Commission B12649/Page 2 August 27,1987

4. Distorted or questionable signals are inspected with the rotating pancake coil (RPC). If any tube contains a questionable signal in the F* zone which is not positively resolved by the bobbin-probe or RPC-probe inspections, it is plugged as a conservative u rective measure.
5. Independent data analysis, and conse, 'ative resolution of discrepancies by an experienced Level 111 analyst is utili2 rd.
6. The ECT data analysts are qualified on plant-specific basis.

As discussed above, the current Haddam Ner,< Plant inspection utilizes practices that go well beyond Technical Specification requirements and Regulatory Guide 1.83 provisions. This provides a high level of assurance that all defects or significant flaws are identified and plugged during the refueling outage.

FUTURE ROLL-REGION ECT PROGRAMS Future roll-region inspection programs at the Haddam Neck Plant will include at least items 1-6 above, or the equivalent, with the exception of the 100 percent, full-length testing (Item 2.) Full length testing in the future will be applied to at least a 3 percent sample of unflawed tubes, plus all degraded tubes that were identified in previous inspections per Technical Specifications.

In addition, future SG tube inspection programs at the Haddam Neck Plant will continue to feature the prudent, conscientious inspection practices and proactive safety philosophy currently being followed by Northeast Utilities and willinclude the following practices:

1. Assess new developments regarding the Haddam Neck Plant inspection experience, and applicable industry inspection experience.
2. Assess and evaluate the Haddam Neck Plant ECT results to define the nature and mechanism of the tube degradation processes.
3. Perform special inspections and examinations, including tube removal / destructive examination, as appropriate, to ensure that the nature and mechanism of the tube degradation process is accurately defined.
4. Apply ECT equipment technology, as appropriate, for defining tube degradation conditions known to exist in the Haddam Neck Plant SGs or similar PWR SGs.
5. Utilize a data analysis program, as appropriate, that provides a high level of assurance that all significant flaws are properly identified.
6. Utilize an inspection strategy that provides a high level of assurance of identifying all significant defects, as appropriate.

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9 U. S. Nuclear Regulatory Commission B12649/Page 3 August 27,1987 We trust that this information will enable the NRC Staff to complete their review of the proposed Technical . Specification changes and prepare a favorable {

safety evaluation and thereby grant an amendment to the Haddam Neck Plant Operating License.

l Very truly yours, CONNECTICUT YANKEE ATOMIC POWER COMPANY

. A E. Kp,tfo6zka ~ //

l Senior Vice President cc: W. T. Russell, Region I Administrator F. M. Akstulewicz, NRC Project Manager, Haddam Neck Plant

3. T. Shediosky, Resident Inspector, Haddam Neck Plant k% 2:! ,

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