ML18081A898
| ML18081A898 | |
| Person / Time | |
|---|---|
| Site: | Salem, Hope Creek  |
| Issue date: | 12/31/1979 |
| From: | Grier B NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I) |
| To: | Martin T Public Service Enterprise Group |
| References | |
| NUDOCS 8001150109 | |
| Download: ML18081A898 (3) | |
Text
Docket Nos. 50-354 50-355
- ~.
UNITED STATES NUCLEAR REGULATORY COMMISSION REGION I 631 PARK AVENUE KING OF PRUSSIA, PENNSYLVANIA 19406 DEC 3 l 1979 Public Service* Electric & Gas Company ATTN:
Mr. T. J. Martin
- Vice President Engflieering. and Construction 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,
- -~** ~rW,n~~
Boyce H. Gr1eV Director Enclosu.res:
- 1.
IE Information Notice No. 79-36
- 2.
List of Recently Issued IE Information Notices CONTACT:
L. E. Tripp (215;_337-5282) cc w/enc.l s:
E. N. Schwalje-, Manager - Quality Assurance, Engineering and Construction Department 8001150l0C(
Aoz__
ENCLOSURE 1 UNITED STATES NUCLEAR REGULATORY COMMISSION OFFICE OF INSPECTION AND ENFORCEMENT WASHINGTON, D.C.
20555 SSINS No. :
6870.
Accession No:
7.910250519
- IE Information Notice No~ 79-36 Date: December 31, 1979
- Page 1 of.1 COMPUTER CODE DEFECT IN STRESS ANALYSIS OF PIPING ELBOW Description* a*f 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 factor for the individual moments.
The correct stress may be higher or lower than calculated by NUPIPE, depending on. the loading condition.
Four conditions mus.t exist for the possibility of the calculation of an incorrect stress in the NUPIPE code:
- 1. *an USAS 831. 1. 0 - 1967 Code analysis 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 1ocal 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 for a similar defect to occur in other piping analysis 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, further licensee actions may be requested or required. If you have any questions regarding this matter, please contact the Director of the appropriate NRC Regi o.na l Office.
No written response to this IE Information Notice is required.
. In.formation Notice No *.79-12A 79-27 79-28 79-29 79-30 79-31 79-32 79-33-*
79-34.
79-35 ENCLOSURE 2 IE Information Notice No. 79-36 Date:
December 31, 1979 Page 1 of 1 RECENTLY ISSUED IE INFORMATION NOTICES
- Subject Date
- Issued* to
.bsued Attempted Damage to New.
11/9/79 All Fuel Faci l itie*s,
. Fue-1 Assemblies Research Reactors and r
Power Reactors with an Operating License (OL) or Construction Permit (CP)
Steam Generator Tube 11/16/79 All Powe.r Reactor Faci-Ruptures at Two PWR lities with an OL or CP Facilities Overloading of Structural i1115ng All Power Reactor Faci-Elements Due to Pipe Support lities with an OL or CP Loads Loss of Nonsafety Related
.11/19/79 All Power Reactor Faci-
- Reactor Coolant System In-lities-with an OL or CP strumentation During Operation Reporting of Defects and 12/6/79 Al 1 Power *Reactor Faci-Noncompliances, 10 CFR lities with an OL Part 21 or CP Use of Incorrect Amplified.
12/13/79 A 11 Power. React*or F aci -
Response Spectra (ARS) lfties with an OL or CP Separation* of Electrical 12/21/79 All Power Reactor Faci-
. Cables for HPCI and ADS lities with an OL or CP Improper Clos.ure of Primary 12/21/79* All Power Reactor Faci-Containment Access Hatches lities with an OL or CP Inadequate Design of Safety-12/31/79 All Power Reactor Faci-Related Heat Exchangers 1 ities with an OL or CP Control of Maintenance "12/31/79 All Power Reactor Faci-and Essential Equipment lities with an OL or CP