ML19209D083
| ML19209D083 | |
| Person / Time | |
|---|---|
| Site: | Comanche Peak  |
| Issue date: | 10/11/1979 |
| From: | Gary R TEXAS UTILITIES ELECTRIC CO. (TU ELECTRIC) |
| To: | Baer R Office of Nuclear Reactor Regulation |
| References | |
| 10010, NUDOCS 7910190377 | |
| Download: ML19209D083 (3) | |
Text
Log # TXX-3055 File 10010 TEXAS UTILITIES GENERATING COMPANY 2001 BRYAN TOWER
- DALLAS. TEXAS 75201 R. J. GARv October 11, 1979 Mr. Robert L. Baer Chief Light Water Reactors Branch No. 2 Division of Nuclear Reactor Regulation U. S. Nuclear Regulatory Comission Washington, D.C.
20555
SUBJECT:
COMANCHE PEAK STEAM ELECTRIC STATION SAFETY-RELATED PROCESS INSTRUMENTATION TUBING MOUNTING DOCKET NOS. 50-445 AND 50-446
REFERENCE:
APPLICANT'S LETTER TO BAER DATED AUGUST 28, 1979
Dear Mr. Baer:
Subsequent to my letter to you dated August 28, 1979, ther:
were several telephone conversations between your staff and our engineering group which clarified the design provisions.
The following documents this clarification and supercedes my previous letter.
In the course of designing and constructing Comanche Peak Steam Electric Station (CPSES), it has been identified that there is a lack of regulatory or industry guidance 'r safety-related process instrumentatior, tubing mounting a-
. ode applicability. Further, a description of the met iode '
handling this equipment is not required in Regulato-2 I-70 " Standard Format and Content for Safety Analy>
in the Standard Review Plans.
In light of this situat1on, Texas Utilities Generating Company (TUGCO) wishes to inform the Staff that the following approach is being taken on CPSES:
1.
All ASME Class 2 or 3 tubing connecting process instruments to ASME III Class 2 and 3 piping are being seismically supported.
NOTE: The CPSES design does not include any ASME III, Class 1 process instrument tubing.
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TXX-3055 October 11, 1979 2.
All ASME Class 2 or 3 tubing connecting safety-related process instruments to non-ASME III HVAC piping or duct work are being seismically supported.
3.
All instrument tubing, valves and fittings forming ASME III Class 2 or 3 pressure boundaries will be purchased, instal-led and tested in accordance with the requirements of ASME III Class 2 or 3 and will be supported as described in 6. below.
4.
The seismic tubing support design considers movements of the connecting piping in relation to the tubing.
5.
Any welding of non-NF seismic tubing supports is per AWS specification consistent with that perfomed on other safety-related, non-ASME supports.
6.
The boundary of jurisdiction of ASME code section III, Class 2 or 3 tubing extends to the instrument.
In lieu of ASME subsection NF, seismically qualified support systems may be employed for process instrument tubing from the instrument root valve to the instrument. Subsection NF supports will be employed to the instrument root valve.
7.
The Quality Assurance program governir.g non-NF supports is the NRC approved QA program governing non-ASME work which meets the requirements of Appendix B to 10CFR Part 50.
8.
The material used for fabrication of non-NF seismic instrument tubing supports is purchased with certificates of compliance to applicable ASTM standards.
9.
Existing seismically designed support systems such as cable tray hangers or conduit supports may be used for tubing supports as pennitted by 6. above. Any necessary re-analysis will be fonned to justify the additional loads.
TUGC0 believes this approach is consistent with the need to ensure the integrity of the instrumentation tubing for safety applications to protect the health and safety of the public.
This information will be included in a future amendment to the FSAR.
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TXX-3055 October 11, 1979 The above procedure for handling safety-related process instru-mentation tubing mounting is being forwarded for your review and concurrence. Your expeditious response in this matter is requested.
Sincerely yours, R. J. Gary RJG:skf
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