ML022400790
| ML022400790 | |
| Person / Time | |
|---|---|
| Site: | Millstone, Davis Besse, Cook  |
| Issue date: | 01/24/2002 |
| From: | Allen Hiser Office of Nuclear Reactor Regulation |
| To: | Harrison J, Jacob Zimmerman Office of Nuclear Reactor Regulation |
| References | |
| FOIA/PA-2002-0229 | |
| Download: ML022400790 (2) | |
Text
cobZmmema Re.VH.NozleStats.RPagel!
From:
Allen Hiser To:
Jacob Zimmerman; John Harrison Date:
Thu, Jan 24, 2002 3:04 PM
Subject:
Re: VHP Nozzle Status Report Update John I had a couple of minor revisions to the Millstone 2 write-up, which is attached. Let me know if you agree with the changes.
Allen
>>> John Harrison 01/24/02 02:16PM >>>
- Jake, Updated report attached per your request.
John
>>> Jacob Zimmerman 01/24/02 01:17PM >>>
Please send me you updated information by COB today. I plan to issue tomorrow's update by noon tomorrow. Attached is last week's status report.
John H. - Brief summary of today's Millstone 2 meeting.
Stephen S. - Brief summary of yesterday's Davis-Besse meeting.
John Stang - Status of D.C. Cook's inspections (i.e., plan to start when?, etc..)
Allen Hiser - Any updates to closeout letters and status of EMCB reviews.
- Thanks, Jake CC:
Andrea Lee; Beth Wetzel I7
,cob Zimmerman - R e: VHP Nozzle status, Rep0rt Update
/3 - Cý, /
Jacob Zimmerman - Millstone 2 01,-24-02.wpd Page 1 PRE-DECISIONAL INFORMATION - NOT FOR PUBLIC DISCLOSURE STATUS REPORT BULLETIN 2001-01, CIRCUMFERENTIAL CRACKING OF REACTOR PRESSURE VESSEL HEAD PENETRATION NOZZLES PLANTS WITH REFUELING OUTAGES SPRING 2002 Millstone, Unit 2 (February 2002)
Licensee Plans/Commitments: The licensee has committed to an inspection that will interrogate the nozzle base material and the weld material using a rotating UT transducer (this plant does not have thermal sleeves in its CRDM nozzles). The licensee has concluded that a visual inspection is not viable at this time because of the contoured insulation, presence of asbestos, restricted access, and ALARA concerns.
On January 24, 2002, the licensee presented their plans to inspect the VHP nozzles.
Currently, they plan to inspect 100% of the nozzles. If, however, the inspection equipment fails prior to this goal, they hope to be able to justify inspecting fewer nozzles. Though, this justification would only be attempted if no unacceptable flaws had been identified in any other nozzles already examined. The licensee presented the statistical analysis that they would use to support this contingency plan. The presentation also included a description of the equipment, technology, and methods to be utilized to interrogate the nozzles and to visually depict the transducer data. One new approach proposed by this licensee is the use of UT data to determine the presence of leakage evidence in the interference fit portion of the CRDM nozzle. This approach was supported in the meeting by the contractor (Framatome) comparing top-of-the-head visual examination results and UT results from inspections conducted in 2001. The material presented supported a finding that all nozzles with visual evidence of leakage had UT results demonstrating leakage evidence in the interference fit portion of the CRDM nozzle.
Staff Position: The examination equipment, technology, and methods proposed to be utilized by the licensee in their upcoming outage to inspect the nozzles appear to provide an effective examination, including the new application of UT data to detect evidence of leakage. However, the staff did not agree with the licensee's statistical analysis used to justify inspecting fewer than 100% of the nozzles, and told that licensee that inspection of 100% of the nozzles is expected.
Planned Meetings & Teleconferences: None.
ACTION ITEM: The licensee needs to submit the information presented in the January 24 meeting for the staff to review, including the new application of UT data to detect evidence of leakage.
PRE-DECISIONAL INFORMATION - NOT FOR PUBLIC DISCLOSURE