ML20106B579

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Submits Plans for Implementing Interim Tendon Surveillance Program,In Response to Concerns.Surveillance Program Will Be Based on Proposed Tech Spec SR 5.2.2,submitted in DW Warembourg
ML20106B579
Person / Time
Site: Fort Saint Vrain Xcel Energy icon.png
Issue date: 01/31/1985
From: Gahm J
PUBLIC SERVICE CO. OF COLORADO
To: Johnson E
NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION IV)
References
P-85039, TAC-54639, NUDOCS 8502110687
Download: ML20106B579 (3)


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16805 WCR 19 1/2, Platteville, Colorado 80651 January 31, 1985 Fort St. Vrain Unit #1 P-85039 Regional Administrator Region IV U. S. Nuclear Regulatory Commission 611 Ryan Plaza Drive, Suite 1000 Arlington, Texas 76011 Attn: Mr. E. H. Johnson

SUBJECT:

Interim Fort St. Vrain Tendon Surveillance Program

REFERENCES:

PSC Letter, D. W. Warembourg to E. H. Johnson 12/14/84(P-84523)

Dear Mr. Johnson:

In response to the cor.cerns expressed by the NRC we are submitting for your evaluation our plans for implementing an interim tendon surveillance program.

The surveillance program will be based on proposed Technical Specification SR 5.2.2 as submitted in Reference 1 and will include those tendons considered accessible in Reference 1.

PSC plans to implement the surveillance program based on information gathered in our original assessment effort and your expressed concerns for determining the present overall level of corrosion and the current rate of corrosion.

The majority of this program has already been started as a continuing effort following completion of tendon testing we had previously committed to perform. The entire program will be implemented by March 1, 1985 and will be based on an eighteen month cycle, as cited in the submitted SRs.

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i Tendon Surveillance Specification SR 5.2.2 includes five (5)' sections which PSC plans to treat as follows during this interim period.

1. SAMPLE WIRES INSERTED INTO TENDONS WITH AREAS OF KNOWN CORROSION No action will be initiated during the interim period.

The sample wires currently in the tendens are not necessarily in tendons with areas of known corrosion. The tendons with areas of corrosion are currently being identified and supplias of sample wires are currently being investigated.

2. ATMOSPHERIC SAMPLES OF TENDON TUBES No action will be initiated during the interim period.

Tendon caps have been removed on 'most tendons for examinations and air, therefore, was introduced into the tubes. The corrosion prevention system has not been finalized as of this date and sampling of the tubes atmosphere would provide no useful information. During the original corrosion determination investigation the atmospheres in 97 wobes were sampled and tested. The results of these tests have been supplied to the NRC.

3. VISUAL EXAMINATION OF ACCESSIBLE TENDONS 4

During the interim period PSC will perform this section as it was submitted to the NRC. A visual examination of at least 5% of the accessible ancher assemblies for the top crosshead and circumferential tendons shall be performed.

A visual examination of at least 33% of the accessible ancher assemblies for the longitudinal and bottom-crosshead tendons shall be performed. This will include re-examination of tendons with areas of known corrosion to obtain information on the current rate of corrosion'. In addition to the required percentage of tendons, an additional two repeat tendons will be_ examined to. provide

.for continuous monitoring of corrosion rate.

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4. TENDON LIST OFF TEST During the interim period PSC will perform this section as it was submitted to the NRC. Lift off test of at least 5%

of the accessible top crosshead tendons and circumferential tendons shall be performed. Lift off test of at least 15% of the accessible longitudinal tendons and bottom croschead tendons shall be performed. In addition to the required percentage of tendons, an additional two repeat tendons will be tested to provide for continuous monitoring of corrosion rate.

5. REPORT OF TENDON EXAMINATION RESULTS

,e At the end of the interim period a report will be prepared covering the testing done during the interim period. This special report will be submitted to the NRC at that time.

If specification SR5.2.2 is formally approved prior to the end of the eighteen month interim period, the special-report will be prepared indicating the status at that time.

Please be aware that the Specification SR 5.2.2 submitted in Reference I was a preliminary Technical Specification submittal, only for the purpose of presenting our rational for a tendon surveillance program.

We trust this provides the requested commitment to begin an interim tendon surveillance program and satisfies your concerns. If there are any further questions concerning the PCRV tendons please contact me or Mr. Chuck Fuller at (303) 785-2223.

Sincerely, J. W. Gahm Manager, Nuclear Production Fort St. Vrain Nuclear Generating Station JWG:AR/djc