TXX-6951, Interim Deficiency Rept CP-87-58 Re Modeling Errors in Computer Code RELAP-3.Initially Reported on 870814. Reanalysis of Affected Pipe Whip Restraint Designs Using RELAP-5 in Progress.Next Rept Will Be Submitted by 880203: Difference between revisions
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=M Log # TXX-6951 | |||
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r- | File # 10110 | ||
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903.6 7UELECTR/C Ref#'10CFR50.55(e)- | |||
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November' 16', 1987: | November' 16', 1987: | ||
William G. Counsil Ew:utive We Prewknt | William G. Counsil Ew:utive We Prewknt U. S. Nuclear Regulatory Commission q | ||
U. S. Nuclear Regulatory Commission | Attn: Document' Control Desk i | ||
Washington, D. C. | |||
20555 j | |||
'I | |||
==SUBJECT:== | ==SUBJECT:== | ||
COMANCHE PEAK STEAM ELECTRIC STATION (CPSES) | COMANCHE PEAK STEAM ELECTRIC STATION (CPSES) 1 DOCKET NOS. 50-445 AND 50-446 COMPUTER MODELING ERROR: | ||
COMPUTER MODELING ERROR: | RELAP-3 1 | ||
SDAR CP-87-58 (INTERIM REPORT) | |||
I Gentlemen: | I Gentlemen: | ||
On August 14, 1987, we verbally notified your Mr. H. S. Phillips.of a | j On August 14, 1987, we verbally notified your Mr. H. S. Phillips.of a | ||
'] | |||
RELAP-3. Our last interim report was logged TXX-6707 dated September 14, | potentially reportable. item involving modeling errors in the ceouter code, RELAP-3. Our last interim report was logged TXX-6707 dated September 14, | ||
1987. After further evaluation we have determined that this'. item is | ) | ||
reportable under the provisions of 10CFR50.55(e) and the required information | 1987. After further evaluation we have determined that this'. item is | ||
Description of Deficiency | ) | ||
reportable under the provisions of 10CFR50.55(e) and the required information i | |||
design of pipe whip restraints. .A check of the RELAP-3 results for the main steam lines using RELAP-5 determined that the use of RELAP-3 resulted in | follows. | ||
the RELAP-3 values may have resulted in non-conservative pipe whip restraint- | Description of Deficiency The computer code RELAP-3 was used in calculating pipe rupture blowdown in the. | ||
The cause of this deficiency is the modeling error in the RELAP-3 computer code. The deficiency | design of pipe whip restraints..A check of the RELAP-3 results for the main steam lines using RELAP-5 determined that the use of RELAP-3 resulted in 1 | ||
Safety Implications Failure of pipe whip restraints could adversely affect the ability of safety-related systems to perform as required following post accident conditions, due to the effects from the increased pipe whip and jet | miscalculation of loads applied to pipe whip restraints. A detailed review of 1 | ||
8711200079 871116 | the computer code identified a modeling error in RELAP-3. | ||
As a result, use of the RELAP-3 values may have resulted in non-conservative pipe whip restraint-designs. | |||
The cause of this deficiency is the modeling error in the RELAP-3 computer code. | |||
The deficiency extends to all pipe whip restraints designed using data provided by RELAP-3. | |||
Safety Implications Failure of pipe whip restraints could adversely affect the ability of safety-related systems to perform as required following post accident conditions, due to the effects from the increased pipe whip and jet r | |||
impingement zones of influence. | |||
8711200079 871116 | |||
[ | [ | ||
l | DR ADOCK 0500 5 | ||
J l | |||
k 400 hrth Olive Street LB 81 Da!!as, Texas 75201 | |||
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a | a | ||
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TXX-6951 | TXX-6951 I | ||
November 16, 1987 f | |||
l We are currently conducting a reanalysis of the affected pipe whip restraint designs using RELAP-5. Our corrective actions and schedule of completion for this deficiency will be submitted no later than February 3, 1988. | Page 2 of 2 | ||
Very truly yours, | ) | ||
Corrective Action l | |||
We are currently conducting a reanalysis of the affected pipe whip restraint designs using RELAP-5. | |||
Our corrective actions and schedule of completion for this deficiency will be submitted no later than February 3, 1988. | |||
Very truly yours, | |||
) | |||
69166 W. G. Counsil l | 69166 W. G. Counsil l | ||
HAM /grr | HAM /grr j | ||
Resident Inspectors, CPSES (3) | c - Mr. R. D. Martin, Region IV Resident Inspectors, CPSES (3) i I | ||
1 1}} | 1 1}} | ||
Latest revision as of 00:23, 3 December 2024
| ML20236Q469 | |
| Person / Time | |
|---|---|
| Site: | Comanche Peak  |
| Issue date: | 11/16/1987 |
| From: | Counsil W TEXAS UTILITIES ELECTRIC CO. (TU ELECTRIC) |
| To: | NRC OFFICE OF ADMINISTRATION & RESOURCES MANAGEMENT (ARM) |
| References | |
| CP-87-58, TXX-6951, NUDOCS 8711200079 | |
| Download: ML20236Q469 (2) | |
Text
{{#Wiki_filter:m s- \\ i e =M Log # TXX-6951 -{ L d File # 10110 ._,r- =. 903.6 7UELECTR/C Ref#'10CFR50.55(e)- ) November' 16', 1987: William G. Counsil Ew:utive We Prewknt U. S. Nuclear Regulatory Commission q Attn: Document' Control Desk i Washington, D. C. 20555 j 'I
SUBJECT:
COMANCHE PEAK STEAM ELECTRIC STATION (CPSES) 1 DOCKET NOS. 50-445 AND 50-446 COMPUTER MODELING ERROR: RELAP-3 1 SDAR CP-87-58 (INTERIM REPORT) I Gentlemen: j On August 14, 1987, we verbally notified your Mr. H. S. Phillips.of a '] potentially reportable. item involving modeling errors in the ceouter code, RELAP-3. Our last interim report was logged TXX-6707 dated September 14, ) 1987. After further evaluation we have determined that this'. item is ) reportable under the provisions of 10CFR50.55(e) and the required information i follows. Description of Deficiency The computer code RELAP-3 was used in calculating pipe rupture blowdown in the. design of pipe whip restraints..A check of the RELAP-3 results for the main steam lines using RELAP-5 determined that the use of RELAP-3 resulted in 1 miscalculation of loads applied to pipe whip restraints. A detailed review of 1 the computer code identified a modeling error in RELAP-3. As a result, use of the RELAP-3 values may have resulted in non-conservative pipe whip restraint-designs. The cause of this deficiency is the modeling error in the RELAP-3 computer code. The deficiency extends to all pipe whip restraints designed using data provided by RELAP-3. Safety Implications Failure of pipe whip restraints could adversely affect the ability of safety-related systems to perform as required following post accident conditions, due to the effects from the increased pipe whip and jet r impingement zones of influence. 8711200079 871116 [ DR ADOCK 0500 5 J l k 400 hrth Olive Street LB 81 Da!!as, Texas 75201 ._o
a \\ i i TXX-6951 I November 16, 1987 f Page 2 of 2 ) Corrective Action l We are currently conducting a reanalysis of the affected pipe whip restraint designs using RELAP-5. Our corrective actions and schedule of completion for this deficiency will be submitted no later than February 3, 1988. Very truly yours, ) 69166 W. G. Counsil l HAM /grr j c - Mr. R. D. Martin, Region IV Resident Inspectors, CPSES (3) i I 1 1}}