ML20236B077

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Forwards Evaluation of Ultrasonic Exam Indications on RCS Loop B Hot Leg Elbow... & Ultrasonic Insp of Statically Cast Stainless Steel Elbow.... Results of Evaluation Show That Structural Integrity of Elbow Not Compromised
ML20236B077
Person / Time
Site: Trojan File:Portland General Electric icon.png
Issue date: 07/24/1987
From: Cockfield D
PORTLAND GENERAL ELECTRIC CO.
To:
NRC OFFICE OF ADMINISTRATION & RESOURCES MANAGEMENT (ARM)
Shared Package
ML20236B080 List:
References
TAC-65315, NUDOCS 8707280329
Download: ML20236B077 (2)


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l emet. !ame EE UM David W. Cockfield Vice President, Nuclear .

July 24, 1987 Trojan Nucicar Plant.

Docket 50-344 License NPF-1 U.S. Nuclear Regulatory Commission ATTN Document Control Desk Washington DC 20555

Dear Sir:

Reactor Coolant System Thermal Expansion On June 16, 1986, the Nuclear Regulatory Commission (NRC) issued a Safety Evaluation Report (SER) on the Trojan Reactor Coolant System (RCS) thermal expansion issue. The SER requested Portland General Electric Company (PGE) to perform an ultrasonic (UT) reexamination of the "B" RCS loop elbow. A UT examination of this elbow had been performed in 1986 as part of the RCS inspection. i l

As previously discussed with the NRC (Terence Chan), the reexamination of this elbow was performed during the 1987 refueling outage. Unlike the 1986 l 1

UT examination, which was performed with manual equipment, the 1987 exami-I nation was performed utilizing the IntraSpect/98 Ultrasonic Imaging System.

This system is a computer-enhanced, automated UT examination system. The l

system detected seven indications. Two of these indications were also observed with manual UT equipment. The other five could not be seen with the manual equipment. The seven indications are very small (<0.3 inches in the maximum dimension), do not coincide with the location of highest cal-culated strain, and are most likely manufacturing anomalies and/or scratch marks. A report describing the examination and results is provided as Attachment 1.

Utilizing the data from tha inspection, the indications were sized and then  ;

evaluated to verify that the indications were within allowable limits and '

the structural integrity of the cibow was not compromised. The results of this evaluation are provided as Attachment 2 and demonstrate the structural integrity of the elbow has not been compromised. i

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8707280329 870724 g PDR ADOCK 05000344 j P PDR g\ t 121 S.W Salmon Street, Portland, Oregon 97204

a Portlared W M'ioCosiirsiy Document Control Desk ,

July 24, 1987 Page 2 PGE is in. agreement with the evaluations and conclusions provided in the attachments. We intend to reexamine this elbow in 1988 to verify that the indications are unchanged. Reexamination will follow the recommendations in Attachment 2. We trust this'information is satisfactory to resolve this issue. .\

Sincerely, Attachments c: Mr. John B. Martin Regional Administrator, Regfon V U.S. Nuclear Regulatory Commission Mr. R. C. Barr NRC Resident Inspector Trojan Nuclear Plant Mr. David Kish, Director State of Oregon Department of Energy

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