ML021160004
| ML021160004 | |
| Person / Time | |
|---|---|
| Site: | Watts Bar  |
| Issue date: | 04/22/2002 |
| From: | Pace P Tennessee Valley Authority |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| IEB-01-001 | |
| Download: ML021160004 (4) | |
Text
Tennessee Valley Authority, Post Office Box 2000, Spring City, Tennessee 37381-2000 APR 2 22002 10 CFR 50.54(f)
U.S. Nuclear Regulatory Commission ATTN:
Document Control Desk Washington, D. C.
20555 Gentlemen:
In the Matter of
)
Docket No.50-390 Tennessee Valley Authority WATTS BAR NUCLEAR PLANT (WBN)
UNIT 1 -
BULLETIN 2001-01 CIRCUMFERENTIAL CRACKING OF REACTOR PRESSURE VESSEL HEAD PENETRATION NOZZLES -
RESPONSE TO ITEM 5 The purpose of this letter is to provide TVA's response for the information requested in Item 5 of the subject bulletin for WBN Unit 1. TVA provided the remaining applicable responses to the bulletin on August 31, 2001.
The information for Item 5 was requested to be provided 30 days after plant restart following the next refueling outage.
TVA restarted WBN Unit 1 following the completion of the Cycle 4 refueling outage on March 21, 2002.
The enclosed provides the information requested by the bulletin.
There are no regulatory commitments identified in the response to this bulletin.
If you have any questions concerning this information, please contact me at (423) 365-1824.
Sincerely, P.
L.
Pace
- Manager, Site Licensing and Industry Affairs A--p Printed on repycoed pape
U.S. Nuclear Regulatory Commission Page 2 APR 2 2 2002 Subscribed and sworn to before me on this 2.2r-day of I.002 Notary Uiblic My Commission expires I2,0 Enclosure cc (Enclosure):
NRC Resident Inspector Watts Bar Nuclear Plant 1260 Nuclear Plant Road Spring City, Tennessee 37381 Mr.
L.
Mark Padovan, Senior Project Manager U.S.
Nuclear Regulatory Commission MS 08G9 One White Flint North 11555 Rockville Pike Rockville, Maryland 20852-2738 U.S. Nuclear Regulatory Commission Region II Sam Nunn Atlanta Federal Center 61 Forsyth St.,
SW, Suite 23T85 Atlanta, Georgia 30303
ENCLOSURE WATTS BAR NUCLEAR PLANT (WBN)
UNIT 1 BULLETIN 2001-01 CIRCUMFERENTIAL CRACKING OF REACTOR PRESSURE VESSEL HEAD PENETRATION NOZZLES The following provides TVA's response for the requested information in Item 5 of the subject bulletin for WBN Unit 1.
This information was requested by the bulletin to be provided 30 days after plant restart following the next refueling outage.
TVA completed the Watts Bar Unit 1 Cycle 4 refueling outage on March 21, 2002.
Item 5 Addressees are requested to provide the following information within 30 days after plant restart following the next refueling outage:
- a.
a description of the extent of VHP nozzle leakage and cracking detected at your plant, including the number, location, size, and nature of each crack detected;
- b.
if cracking is identified, a description of the inspections (type, scope, qualification requirements, and acceptance criteria), repairs, and other corrective actions you have taken to satisfy applicable regulatory requirements.
This information is requested only if there are any changes from prior information submitted in accordance with this bulletin.
RESPONSE
- a.
WBN did not remove or lift the insulation which surrounds the reactor vessel head penetration nozzles to perform an inspection during the Cycle 4 refueling outage due to the low susceptibility ranking, the low operating temperatures, and the low effective full power years of operation.
In the response to NRC'sBulletin 2002-01, "Reactor Pressure Vessel Head Degradation and Reactor Coolant Pressure Boundary Integrity," dated April 2,
- 2002, TVA committed to perform an additional inspection of the reactor vessel head penetrations during the next refueling outage.
For the WBN Unit 1 Cycle 4 outage, as in each refueling outage during disassembly of the reactor vessel, inspections were performed to detect any signs of boric acid residue, corrosion, or active leaks.
TVA visually inspected the CRDM eyebolts on the CRDM seismic support platform, inspected the reactor vessel head flange insulation before removal, and E-1
ENCLOSURE WATTS BAR NUCLEAR PLANT (WBN)
UNIT 1 BULLETIN 2001-01 CIRCUMFERENTIAL CRACKING OF REACTOR PRESSURE VESSEL HEAD PENETRATION NOZZLES inspected the surface of the reactor head metal after this insulation was removed.
Following the removal of the insulation, the pressure retaining bolted connections on the reactor vessel flange area and accessible areas of the reactor vessel head were inspected for any signs of corrosion or leakage.
Inspections for boric acid crystals, corrosion, or active leaks above the top of the insulation which surrounds the CRDM penetrations included 100 percent inspection of the lower canopy seal welds and the instrument ports (conoseals).
No signs of boric acid crystals, active leaks or corrosion were identified around, above, or on the reactor vessel during the Cycle 4 refueling outage.
TVA has not identified any signs of leakage since the Cycle 2 refueling outage.
- b.
This question does not apply.
E-2