ML18081A899
| ML18081A899 | |
| Person / Time | |
|---|---|
| Site: | Salem  |
| Issue date: | 12/31/1979 |
| From: | Grier B NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I) |
| To: | Schneider F Public Service Enterprise Group |
| References | |
| NUDOCS 8001150113 | |
| Download: ML18081A899 (3) | |
Text
UNITED ST ATES NUCLEAR REGULATORY COMMISSION REGION I 631 PARK AVENUE KING OF PRUSSIA, PENNSYLVANIA 19406 Docket No. 50-272 DEC 3 1 1979 Public Service Electric and Gas Company AITN:
Mr. F. W. Schneider Vice President - Production 80 Park Place Newark, New Jersey 07101 Gentlemen:
The enclosed IE Information Notice No. 79-36 provides information on a computer code defect which can result in incorrect stress values for piping elbows.
Sincerely,
. M,W, Yv11~~
- Director
Enclosures:
- 1.
IE Information Notice No. 79-36
- 2.
List of Recently Issued IE. Information Notices CONTACT:
L. E. Tripp.
(215-337-5282) cc* w/encls:
F. P. Librizzi, General Manager - Electric Production E. N. Schwalje, Manager - Quality Assurance R. L Mittl, General Manager - Licensing* and Environment H. J. Midura, Manager - Salem Generating Station VJ
- 18 0 0 Jl. 1 5 () 11.?:1
- e-ENCLOSURE 1
.UNITED STATES NUCLEAR.REGULATORY COMMISSION OFFICE OF. INSPECTION *AND ENFORCEMENT WASHINGTON, D.C.
20555 SSlNS No.:
6870 Accession No:
7910250519
- *1E Information Notice No. 79-36 Date:.December 31, 1979
- Page 1 of.1 COMPUTER CODE DEFECT.IN STRESS ANALYSIS OF PIPING ELBOW Description* of Circumstances:
The NRc*was informed on December 17, 1979 that a computer code, NUPIPE, used in the stress analysis of piping systems contained a defect which could result in incorrect stress values at one end of piping elbows.
This defect was iden-tified from discussions with a user of NUPIPE and the NUPIPE code developers.
The stress calculation e.rror can occur when a flexible joint is modeled at the end of an elbow (ELBOW-ELASTOJT connection in NUPIPE terminology)..
This defect in the NUPIPE code is in the transformation of the loads in the ELASTOJT coordin-ate axis to the piping ELBOW coordinate axis. The *incorrect coordinate axis transformation may incorrectly interchange the torsion and bending moment loads on the piping elbow.
This can result in the incorrect assignment of the *stress intensification fac.tor for the individual moments.
The correct stress may be higher* or lower than calculated by NUPIPE, depending on the loading condition.
Four conditions must exist for the possibility of the calculation of an incorrect stress in the NUPIPE code:
L. an USAS 831.1. 0. - 1967 Code ana 1 ys is is being done, and 2~ an ELBOW-ELASTOJT connection exists, and 3~.
an* absolute sum of two load. cases is being calculated, and
- 4.
the. ELBOW torsional moment axis does not align with the ELASTOJT local x-axis.
Possible users of the NUPIPE code include the code developer, Stone and Webster, EG&G (Idaho Falls), and those using the Cybernet system.
The NRC is currently reviewing the extent of usage of the NUPIPE code and the generic implications for other facilities. There is a potential fo.r a similar defect to occur in other pipinganalysfs computer codes.
This Information Notice is provided as early notification of a possible signif-icant matter. It is expected that recipients will review the information for possible applicability to their facilities.
No specific action is requested in response to this Information Notice.
If NRC evaluations so indicate, fu.rther licensee actions niay be requested or required.
If you have any questions regarding this matter, please contact the Director of the appropriate NRC Regional Office.
No written response to this IE Information Notice is required.
Information
- Notice No *.
79-27 79-28 ENCLOSURE 2
- IE: Information Notice No. 79-36 Date:
December 31, 1979 Page* l of 1 RECENTLY ISSUED IE INFORMATION NOTICES Subject Attempted Damage to New
- Fuel Assemblies Date Issued*
.11/9/79
- ~ssued' to.
All Fuel Facilitie*s,
- .. Research Reactors and Power Reactors with an Operating License (OL) or Construction Permit (CPJ Steam Generator Tube 11/16/79 All Powe.r Reactor Faci-Ruptures at Two PWR Hties with an OL or CP Fae.fl ities Overloading of Structural ll/16n9
- All Power Reactor Faci-Elements Due to Pipe Support lities with an OL or CP Loads 79-.29 Loss. of Nonsafety Related 11/19/79 All Power Reactor Faci-79-30 *.
79-31.
79-32 79-33 79-34 79-35
.. Reactor Coolant System In-lities with an OL or CP strumentation During Operation Reporting of Defects and Noncompliances, 10 CFR
- Part: 21.
12/6/79 All Power *Reactor Faci-1 ities with an OL or CP Use of Incorrect Amplified 12/13/79 All Power Reactor Faci-Response Spectra (ARS) lities with an OL or CP Separation of Electrical 12/21/79 All Power Reactor Faci-Cables. for HPCI. and ADS 1 ities with an OL.or CP Improper Closure of Primary 12/21/79 All Power Reactor Faci-Contai nment Access Hatches 1 i ti:es with an. OL or CP Inadequate Design of Safej:y-12/31/79 All Power Reactor Faci-Related Heat Exchangers 1 ities with an OL or CP Control of Maintenance -
and Essential Equipment 12/31/79 All Power Reactor. Faci-lities with an OL or CP