ML20214S527
| ML20214S527 | |
| Person / Time | |
|---|---|
| Site: | Vermont Yankee File:NorthStar Vermont Yankee icon.png |
| Issue date: | 06/02/1987 |
| From: | Capstick R VERMONT YANKEE NUCLEAR POWER CORP. |
| To: | Rooney V Office of Nuclear Reactor Regulation |
| References | |
| FVY-87-60, NUDOCS 8706090303 | |
| Download: ML20214S527 (3) | |
Text
VERMONT YANKEE NU' LEAR POWER CORPORATION C
RD 5, Box 169. Ferry Road, Brattleboro, VT 05301 y
ENGINEERING OFFICE June 2, 1987 1671 WORCESTER ROAD FVY 87-60 FRAMINGH AM, MASSACHUSETTS 01701 7ELEPHOP.E 617-872-8100 United States Nuclear Regulatory Commission Washington, DC 20555 Attention:
Office of Nuclear Reactor Regule* ion Mr. V. L. Rooney, Project Manager BWR Project Directorate No. 2 Division of BWR Licensing
References:
(a) License No. DPR-28 (Docket No. 50-271)
(b) Letter, VYNPC to USNRC, FVY 86-29, dated March 28, 1986 (c) Letter, USNRC to VYNPC, NVY 86-73, dated April 18, 1986 (d) Letter, VYNPC to USNRC, FVY 87-02, dated January 5, 1987
Subject:
Request for Permanent Revision of Routine Inspection Interval Guidance Provided by NUREG-0619 for Feedwater Nozzle PT Examinations - Response to Request for Additional Information.
Dear Sir:
By letter, dated January 5, 1987 (Reference (d)), Vermont Yankee requested a permanent revision to the routine inspection interval guidance contained in Table 2 of NUREG-0619 "BWR Feedwater Nozzle and Control Rod Return Line Nozzle Cracking," for liquid penetrant inspection of the nozzle blend radius.
Pursuant to NRC staff's recent request, Vermont Yankee herein provides the following supplemental information.
ALARA Vermont Yankee's ALARA analysis for performing the feedwater sparger inspection (ultrasonic and dye-penetrant testing of the feedwater nozzles in the drywell as well as visual inspection of the sparger flow holes) concludes that high anticipated dose rates, very high contamination levels, and the potential for high levels of airborne activity are anticipated. The analysis focused on the in-vessel scope of work using man-hour estimates based on the most recent sparger inspection at Vermont Yankee.
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United States Nuclear Regulatory Commission June 2, 1987 Attention:
Mr. V. L. Rooney Page 2 In summary, the analysis results for performing the feedwater sparger inspection are as follows:
Radiological Conditions -
up to - 1.5 rem /hr general areas 27 rad /hr beta 50 mr/hr loose (gamma) 1 rad /hr loose (beta)
- 844 MPC airborne activity Cavity Decon 1.75 rem (from last inspection; 22 man / hours, 80mr/hr)
Inspection set up 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> x 16 men x 10.7 mr/hr = 1.4 rem Inspection Assistance 2 days x 24 hrs / day x 6 men x 11.6 mr/hr = 3.34 rem Inspection 2 shifts x 2 days x 7.5 hrs / shift
- x 2 men x 163 mr/hr = 9.78 rem
(* Actual in-vessel time from historical data)
TOTAL = 16.27 rem 498 manhours Vermont Yankee did not evaluate the use of automated / remote handling devices for the inspection because their use was not recommended by the vendor (GE), nor were reliable devices available.
SCHEDULE AND COST ESTIMATE The schedular impact of the feedwater sparger liquid penetrant inspection has been evaluated based on previous examination experience. Tasks associated with the inspection which impact directly on a refueling outage critical path could amount to two days.
The direct costs associated with the liquid penetrant examination, including setup and inspection, have been estimated at $50,000.
If replacement power costs are considered for two days of additional outage time, the costs associated with this inspection could also be estimated to involve approximately $700,000.
ULTRASONIC TESTING (UT)
Vermont Yankee previously provided [ Reference (d)] the feedwater nozzle UT examination technique and the results of the 1985/1986 outage UT examination of the feedwater nozzle blend radius. The 1985/1986 outage
United States Nuclear Regulatory Commission June 2, 1987 Attention:
Mr. V. L. Rooney Page 3 UT examination results fully supported the 1977, 1979, and 1981 PT examination results which showed that no reportable indications had developed in the feedwater nozzle blend radii following the installation of the new spargers, demonstrating effective resolution of previous bypass leakage concerns.
In order to ensure proper performance of the feedwater inner radius examinations, all examiners are required to have procedure training on the specific inner radius techniques prior to each exam. A prerer ;isite to this training is that each examiner is qualified to SNT-TC-1A, Levels 1 and 2.
Each examination team (L1 and L2) are given approximately 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> of classroom and practical training including time on the Vermont Yankee nozzle mock-up.
Upon completion of the training, a qualification test is given on a previously undisclosed section of the mock-up.
This test is successfully passed by detection of reflectors in the various examination zones as specified by the procedure.
The reflectors and the inside of the mock-up are kept secure from the examiners being qualified. Only upon successful completion of the test are the examiners allowed to perform the actual feedwater nozzle examinations.
CONCLUSION We trust that the information provided herein is responsive to your request. Accordingly, Vermont Yankee reiterates its prior request for NRC concurrence that the routine inspection intervals for feedwater nozzle PT examinations are no longer warranted at Vermont Yankee on the basis of accumulated plant-specific experience; the adequacy of our continuing UT examination and Leakage Detection System Program; the outage schedular and cost impacts; and the maintenance of radiation exposures As Low As Reasonably Achievable (ALARA).
As previously committed in References (b) and (d), Vermont Yankee will continue the once-per-cycle UT examination and the continual monitoring of bypass leakage in accordance with the guidance of Table 2 of NUREG-0619.
Should future UT examinations show reportable indications, a PT inspection will be performed to quantify those indications and Vermont Yankee will continue periodic visual inspections of the spargers in accordance with ASME Section XI (Categories B-N-1 and B-N-2).
In order to fully address this matter in our planning efforts for the 1987 refueling cycle (early August 1987), we request your timely attention to this matter. Should you have any questions or require additional information regarding this issue, please contact this office.
Very truly yours, VERMONT YANKEE NUCLEAR POWER CORPORATION R. W.
apstick Licensing Engineer RWC/sj