ML20078A254
| ML20078A254 | |
| Person / Time | |
|---|---|
| Site: | Point Beach  |
| Issue date: | 01/11/1995 |
| From: | Maxfield G WISCONSIN ELECTRIC POWER CO. |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| PBL-95-17, NUDOCS 9501240334 | |
| Download: ML20078A254 (4) | |
Text
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.I e Wisconsin Electnc POWER COMPANY Point Beach Nuclear Plant 6610 Nuclear Rd Two Rivers.WI 54241 (414) M 2321 PBL 95-0017 January 11, 1995 Document Control Desk U. S.
NUCLEAR REGULATORY COMMISSION Main Station P1-137 Washington, DC 20555 Gentlemen:
DOCKET 50-301 ASME SECTION XI PELIEF REOUEST RR-2-19 POINT BEACH NUCLEAR PLANT UNIT 2 In accordance with 10 CFR 50.55a (g) (5) (iv), Wisconsin Electric Power Company requests relief from Section XI of the American Society of Mechanical Engineers (ASME) Boiler and Pressure Vessel Code, " Rules for Inservice Examination of Nuclear Power Plant Components," 1986 edition, no addenda.
The requirements for which relief is requested apply to the third inservice inspection interval for Point Beach Nuclear Plant, Unit 2.
The third interval began in December 1992 for Unit 2.
The attached relief request, RR-2-19, provides the information needed for the NRC to complete a review and approval as required.
Sincerely, Greg Max ' eld Plant Manager arm Attachment cc:
NRC Regional Administrator NRC Resident Inspector bcc:
R.
E.
Link T.
G. Malanowski S. A.
Patulski G.
M.
Krieser R. A. Newton M.
F.
Baumann J.
B.
Brander T.
G.
Stcskal File C.
T.
Prothero fy.
Reference (s) :
Section XI of tne American Society of Mechanical Engineers (ASME) Boiler and Pressure Vessel Code Relief Request RR-2-19 9501240334 950111
//18 PDR ADOCK 05000301 Jy&[
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ASME SECTION XI RELIEF REOUEST RR-2-19 POINT BEACH NUCLEAR PLANT, UNIT 2 COMPONENT RPV-02-686-A-IRS OUTLET NOZZLE AT 28.5 DEG.
-i RPV-02-686-B-IRS INLET NOZZLE AT 148.5 DEG.
RPV-02-686-C-IRS OUTLET NOZZLE AT 208.5-DEG.
RPV-02-686-D-IRS INLET NOZZLE AT 328.5 DEG.
RPV-687-01-A-IRS SI NOZZLE AT-288.5 DEG.
RPV-687-01-B-IRS SI NOZZLE AT 108.5 DEG.
PZR-RELNOZ-IRS INSIDE RADIUS SECTION PZR-SAFNOZ-1-IRS INSIDE RADIUS SECTION-PZR-SAFNOZ-2-IRS INSIDE RADIUS SECTION PZR-SPRAYNOZ-IRS INSIDE RADIUS SECTION PZR-SURGENOZ-IRS INSIDE. RADIUS SECTION SG-A-INLET NOZZLE-IRS INSIDE RADIUS SECTION SG-A-OUTLET NOZZLE-IRS INSIDE RADIUS-SECTION SG-A-INLET NOZZLE-IRS INSIDE RADIUS.SECTION SG-A-OUTLET NOZZLE-IRS INSIDE RADIUS SECTION EXAM ARPA Figure IWB-2500-7 ISOMETRICS 3
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ISI-PRI-2101 ISI-PRI-2104 ISI-PRI-2105 ISI-PRI-2106 ASME SECTION XI CATEGORY B-D
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ASME SECTION XI ITEM NUMBER j
B3.100 B3.120 B3.140 i
ASME SECTION XI REOUIREMENT TABLE IWB-2500-1 Examination Method:
Volumetric i.
Extent and Frequency:
All' nozzles each interval j
Note 2:
At'least 25% but not more than 50% (credited) of j
the nozzles shall be examined by the end of the first inspection period, and the remainder by the end of the inspection interval.
j ALTERNATE REOUIREMENT i
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PBNP proposes that the allocation requirement of Note 2 be j
waived and that all nozzles be inspected by the end of the interval.
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l REASON FOR PROPOSED ALTERNATE REOUIREMENT The most effective and efficient manner to perform the inner radius examination would be to utilize automated examination techniques and examine all nozzles at or near the same time in j
l the interval.
For the PBNP pressurizer safety nozzles, 3-D modelling has l
been performed on the inner radius examination area.
This modelling has determined that manual examination would require 56 different scans utilizing several different transducers.
The area in which the examiner would be required to be in, while performing the examinations, are high radiation areas.
l Dose rates range from.1 to 2.0 Manrem/ hour, scan time would l
range from 20 to 30 hours3.472222e-4 days <br />0.00833 hours <br />4.960317e-5 weeks <br />1.1415e-5 months <br /> per component utilizing one l
examiner.
Conservatively, 2 Manrem would be expended per manual examination of a nozzle inner raduis section assuming j
the lowest dose rate, least amount of time and one examiner.
Automated examination, utilizing the Phased Array technique, would rrciult in 0.100 Manrem using the same dose rates.
This l
c dose reduction factor of 20 times.
In addition, automated i
inspection techniques generally result in a more accurate l
inspection technique.
Therefore, the automated Phased array technique is the preferred.
The estimated cost associated with performing automated Phased Array examination on four nozzles in one outage are as follows:
Mobilization
$50,000
$50,000 Equipment rental
$3,00C/ day X
8 days
$24,000
=
Manpower S4,000/ day X
8 days
$32.000
=
TOTAL
$106,000 Depending on plant conditions and outage scope, an automated examination would have to be deployed during multiple outages, i
l at the cost
- above, in order to meet the scheduling requirements of Table IWB-2500-1.
Availability of equipment and contractors may make it impractible to perform this examination using the automated techniques.
In addition, l
multiple deployments of the equipment can make this examination technique not cost effective.
l By waiving the requirements of Note 2 the nozzle inner radiun l
examination can be perform using optimal scheduling techniques.
This in turn will result in minimum radiation dose received (reduction estimated at a factor of 20),
I utilization of the most accurate examination technique and an
.werall cost reduction.
r
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There - is no histo.y of any of the subject inner radius l
sections containing any indications, bo'th fabrication and i
inservice related.
This relief request does not reduce the number or change the method of examinations required by ASME Section XI.
All nozzle Inner Radius Section's required to be inspected during the interval will be examined.
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