ML20063N214
| ML20063N214 | |
| Person / Time | |
|---|---|
| Site: | McGuire  |
| Issue date: | 09/14/1982 |
| From: | Tucker H DUKE POWER CO. |
| To: | Adensam E, Harold Denton Office of Nuclear Reactor Regulation |
| References | |
| NUDOCS 8209200098 | |
| Download: ML20063N214 (5) | |
Text
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DUKE PowEn GomWNY l'.o. Ilox 33180 CHAHI,oTTE. N.C. 28242 T E LE 3*mN II AI,11. Tt'GKER (7o4)373-45:38
,,,,p.r.mc,T ist t & FAB,MetDR1Tf4DM September 14, 1982 Mr. Harold R. Denton, Director Office of Nuclear Reactor Regulation U. S. Nuclear Regulatory Commission Washington, D. C.
20555 Attention:
Ms. E. G. Adensam, Chief Licensing Branch No. 4 Re: McGuire Nuclear Station, Unit 1 Docket No. 50-369 Request for Relief from ASME Code Section XI Requirement Determined to be Impractical.
Dear Mr. Denton:
Please find attached two separate requests for relief from Hydrostatic Testing Re-quirements on the Feedwater System to the unit one steam generators, and the unit one Safety Injection System. These piping modifications are tentatively scheduled to be performed during the upcoming outage scheduled to start on October 15, 1982.
It is requested that these relief requests be processed in a timely manner, in order to meet present scheduling activities, and the return of the unit to system operation by January 1, 1983.
If there are any questions on this matter, please advise.
Very truly yours, L. -,
f/
c~.cg A sed Hal B. Tucker PBN/j fw Attachment cc:
Mr. James F. O'Reilly, Regional Administrator Mr. P. R. Bemis U. S. Nuclear Regulatory Commission Senior Resident Inspector-NRC Region II McGuire Nuclear Station 101 Marietta Street, Suite 3100 Atlanta, Georgia 30303 ool 8209200098 820914 DR ADOCK 05000369 p
m-t I
DUKE F0WER COMPANY MCGUIRE NUCLEAR STATION REQUEST FOR RELIEF FROM ASME CODE SECTION XI REQUIREMENT DETERMINED TO BE IMPRACTICAL
- 1) COMPONENT FOR WHICH RELIEF IS REQUESTED:
A.
NAME AND NUMBER Unit One Safety Injection System piping is to be modified in order to prevent check valves from fluttering.
B.
FUNCTION The Safety Injection System provides emergency core cooling to the reactor vessel. This particular affected portion of the system also provides a flow path for removal of decay. heat in the shutdown condition, and also is the primary check valve for the cold leg accumulators.
C.
ASME SECTION III CODE CLASS Equivalent Class 1 D.
VALVE CATEGORY N/A
- 2) ASME CODE SECTION XI REQUIREMENT THAT HAS BEEN DETERMINED TO BE IMPRACTICAL ASME B & PV Code,Section XI,1977 Edition, thru Summer 1978 Addenda, IWA - 4400, IWC - 5000
- 3) BASIS FOR REQUESTING RELIEF:
There are two affected areas of piping in the system. One area is between two check valves, and the other area is also between two check valves.. There are no isolation valves downstream of these primary and secondary check valves to the NC system, therefore it is impossible to isolate these portions of systems. However, there are several approaches to partially pressurizing the system.
m
Page 2 1
The first approach would be to pressurize the (NC) Reactor Coolant System to 2235 pounds, and then use the (NI) Safety Injection pumps to pressurize the N1 Systems against one of the check valve's.
- However, i
this pump pressure is only 1600 pounds, which falls far short of the required test pressure.
The second approach would be to remove the internals from the primary check valves, which go to the NC System, and then pressurize the NC System to 1.02 of 2235 pounds 0500* temperature. However, this method would still not achieve the desired test pressure per the code, because this would be a dead leg pipe with no flow, and the convective and conductive effect of heat transfer possibly would not reach the 500* temperature minimum, as this portion of the system is uninsulated.
This would also require draining the system in order to replace the internals into the check valve, a very timely and very costly procedure."
Therefore, due to orientation of the valves within the system, it is not possible to hydrostatically test the system. However, the alternate examinations as specified in Item 4 are equal to or better than the required testing per the code.
- 4) ALTERNATE EXAMINATION A 100% radiographic examination of all pressure boundary welds, with additional PT examination on root pass welds, and also final pass velds. Also, a hydro test will be performed at the 10-year inspection interval per Section XI of the ASME Code. An inservice leak test cannot be performed on this system because if the check valves hold, the system will not see system pressure.
- 5) IMPLEMENTATION These examinations, with the exception of the hydrostatic test, will be carried out af ter the modification on the (NI) Safety Injection System is complete, and prior to the system being declared operable.
.e
m DUKE POWER COMPANY MCGUIRE NUCLEAR STATION REQUEST FOR RELIEF FROM ASME CODE SECTION XI REQUIREMENT DETERMINED TO BE IMPRACTICAL 1.
COMPONENT FOR WHICH RELIEF IS REQUESTED:
A.
Name and Number Unit 1 steam generator main feedwater nozzles and piping are to be removed and replaced to facilitate installation of flow distribution manifold.
B.
Function The main feedwater system supplies water to the steam generators where it removes heat from the reactor coolant system.
C.
ASME Section III Code Class Equivalent Class 2.
D.
Valve Category N/A.
2.
ASME CODE SECTION XI REQUIREMENT THAT HAS BEEN DETERMINED TO BE IMPRACTICAL ASME B & PV code Section XI, 1977 Edition through Summer 1978 Addenda, Article IWA-4400, IWC-5000 3.
BASIS FOR REQUESTING RELIEF:
Performing a hydrostatic test on the steam generator nozzles and feedwater piping would be impractical, extremely difficult, and very costly due to the following reasons:
A.
Isolation and preparation of this system would result in considerable additicaal radiation exposure to personnel.
B.
Additional time required to gag safety relief valves.
C.
Additional time required to pin or block main steam constant support hangers.
I Page 2 3.
Continued D.
Potential damage due to static load on main steam system caused by water solid condition.
E.
Potential damage to S. G. tube bundle.
F.
Potential leakage through main steam isolation valves, feedwater isolation valves, and other valves in the system (inability to hold pressure).
G.
Potential damage to instrumentation, or considerable delay due to isolation / removal of instrumentation.
In addition to these reasons, the alternate examinations as specified in 4, are equal to or better than the required testing per the code.
4.
ALTERNATE EXAMINATION A 100% radiographic evnmination of all pressure boundary welds, with additional PT examination on root pass welds and also final pass welds. Also, an inservice leak test will be performed on the system, along with a hydro test to be performed at the 10 year inspection interval per Section XI of ASME Code.
5.
IMPLEMENTATION These examinations, with the exception of the hydrostatic test, will be carried out after the feedwater pipe replacement on each steam generator, before the system is declared operable.
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