ML20113G872
| ML20113G872 | |
| Person / Time | |
|---|---|
| Site: | Cooper  |
| Issue date: | 05/05/1992 |
| From: | Horn G NEBRASKA PUBLIC POWER DISTRICT |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| CNSS927149, NUDOCS 9205130095 | |
| Download: ML20113G872 (3) | |
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- =_=_=:n CNSS927149 May 5, 1992 U.S.
Nuclear Regulatory Commission Document control Desk Washington, DC 20555
Subject:
Report of Cooper Nuclear Station Feedwater Hozzle Examinatione per NUREG 0619.
References:
(a)
NUREG M19, BWR Feedwater Nozzle and Control Rod Drive Return Line Nozzle Cracking, published November, 1980.
(b)
- Letter, G.
R. Horn (NPPD) to U.S. NRC, dated January 22, 1991.
Subjects BWR Feedwater Nozzle Inspections, Cooper Nuclear Station, NRC Docket No. 50-298, DPR-46, with attachment.
(c)
Letter, P. W. O'Connor (U.S. NRC) to G.
R. Horn (NPPD),
dated October 2, 1991.
Subject:
Cooper Nuclear Station -
Review of NPPD's Request Regarding Feedwater Nozzle Examination Methods (TAC No. 79612).
Gentlemen In accordance with Reference (a), paragraph 4.4.3.1(2), the following provides the soport of ultrasonic examinations of the feedwater nozzles at Cooper Nuclear Station. These examinations included the nozzle inner radius, nozzle bore, and safe end sections of the feedwater nozzle, as required by NUREG 0619.
The following information is provided in accordance with Section 4.4.3.1 (2) of NUREG 0619.
(a)
By the end of December 1991, there have been seven startup/ shutdown cycles at Cooper Nuclear Station since the last ultrasonic (UT) examination of the feedwater nozzles and visual (VT) examination of the feedwater spargers in 1989.
There have been 148 startup/ shutdown cycles at Cooper Nuclear Station since the initial startup of the plant in 1974.
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U.S. Nucicar Rogulatory Commiccion Hay 5, 1992 page 2 (b)
In 1980, Cooper Nuclear Station removed the feedwater nozzle cladding and installed double piston ring, triple thermal sleeve spargers.
Subsequent to this, baseline ultrasonic and liquid penetrant sxaminations were performed per Cooper Nuclear Station and General Electric procedures. No cracks or recordable indications were ident..fied during these examinations.
In 1982, the feedwater nozzles and spargers were examined by ultrasonic and visual methods, respectively, per Cooper Nuclear f,tation and General Electric procedures.
No cracks or recordable indications were identified during these examinations.
In 1983 and 1984, the feedwater spargers were visually examined per Cooper Nuclear Station and General Electric procedures. No cracks or recordable indications were identified during these examinations.
In 1986, the feedwater_ nozzles and spargers were examined by ultrastnic and visual methods, respectively, per Cooper Nuclear Station and General Electric procedures. No cracks or recordable indications were identified during these examinations.
In 1988, the feedwater spargers were visually examined per Cooper Nuclear Station and General Electric procedures. No cracks or recordable indications were identified during these examinations.
In 1989, the feedwater nozzles and spargers were examined by ultrasonic and visual methods, respectively, per cooper Nuclear Station and General Electric procedures.
No cracks or recordable indications were identified during these examinations.
(c)
There have been no significant changes to procedures or systems that would affect the feedwater temperature or flow.
(d)
In accordance with Reference (a), Section 4.3.2.3, the District was required to perform a penetrant (PT) examination of the feedwatec nozzles during the 1991 Fafueling Outage.
In lieu of this requirement, the District proposed in Reference (b) that an automated Ultrasonic Inspection be performed and supplemental monitoring equipment, both leakage and f atigue monitoring, be inst alled during the 1991 Refueling outage. This was approved-by the commission in Reference (c).
There j
were no recordable indications identified in the course of either the UT l
examinations of the nozzles or the VT examinations of the spargers and accessible portions of the nozzle inner radii during the 1991 Refueling Outage.
U.S. Nuclear Regulatory Commiseion Hay 5, 1992 Page 3 e
(e)
As discussed in Reference (b), the District installed a feedwater J
ij,
nozzle-thermal siveve leak detection system during the 1991 Refueling
>4-Outage.
This system is currently in service.
Leakage measurements during normal plant operation have been a maximum of 0.05 gallons per minute (gpm), considerably below the 0.3 gpm notification threshold
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specified in Reference (a), paragraph 4.3.2.4.
stv:, : t gy,;;?j (f)
There were no crack-like indications ientified from ultrasonic 0, fj examination performed in 1991. The following procedures were used for
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the mitomated UT examination of the three examination zones in each M
feedwater nozzle:
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'%y Procedure Number Procedure TLtle GE-UT-309, Rev. O Planar Flaw Sizing for Nozzle Inner Radius ara Bore Regions 4
00-UT-402, Rev. O UT Alternati'm to NUREG 0619 Not.zle Radius and Bore PT Requirement Supplemental manual UT examinations were conducted in areca where automated UT examinations could not be accomplished due to physical Jaterference with other reactor vessel components finstrument and ntrol rod drive return nozzles).
The following procedure was used to w
perform these er minationes GE-UT-303, Rev. O Procedure for Manual Ultsasonic Examir.ation of Nozzle Inner Raditm Greater than 10 Inch Diameter Ilease contacc me if ycu should require additional information regarding this matter.
Sincerely, i
/
A:7n' Nuclear Powe. Troup Manager GRH:GEHisa cc NRC Regional Office Region IV NRC Resident Inspector Cooper Nuclear Station
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