ML20246F098
| ML20246F098 | |
| Person / Time | |
|---|---|
| Site: | Comanche Peak  |
| Issue date: | 08/22/1989 |
| From: | William Cahill TEXAS UTILITIES ELECTRIC CO. (TU ELECTRIC) |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| TXX-89598, NUDOCS 8908300155 | |
| Download: ML20246F098 (3) | |
Text
p
~} w yy r-
?
a.
.e.
M
_ Log.'# TXX-89598 1-
~
File # 10130-C C.
IR 69-12
[,
MIbbbCIOIb Ref # 100 R2 01:
D,N,',Il,';
' August 22, 1989 U.: S. Nuclear Regulatory Commission
+
Attn: Document Control Desk Washingten D. C.
20555
SUBJECT:
COMANCHE' PEAK STEAM ELECTRIC STATION DOCKET-NOS. 50-445 AND 50-446 2EVISED RESPONSE TO NRC NOTICE OF VIOLATION
-(NOV) 445/8912-V-01 AND 446/8912-V REF:
(1) TV Electric letter TXX-89209 from W. J. Cahill to l*SNRC dated April 24,- 1989 (2) TV Electric letter TXX-89419 from W. J. Cahill to USNRC.
dated June 15, 1989 Gentlemen:
Reference 1 provided our response to the subject NOV.
In that response, we i
stated that low strength bolts were being replaced with high strength bolts and that the replacement would be completed no later.than June 15 1989.
Reference 2-extended our estimated ' completion date to July 31, 1989.
Due to extensive rework activities unrelated to the NOV, bolt replacement for two Unit I-cnubber assemblies has been rescheduled for completion by September 23,
-1989. Uur response has.been revised to indicate the. rescheduled completion date. Our response has also been revised to differentiate'those actions which are being taken for Unit I and those which will be taken for Unit 2.
These matters were discussed with the NRC staff on July 31.'1989 and August 8, 1989.
Revision bars in the right margin of the attached revised response indicate the changed portions of the text.
Sincerely,
(
/
4 William J. Cahill, Jr.
FAM/vid Attachment
.c-hr. R. D. Martin, Region IV Re' -9nt Inspectors, CPSES (3) enn n8886 '
-- M * >
c o
LAttach: nt to TXX-89598
, ' August.22, 1989 JPag3 liof.2-NOTICE OF VIOLATION ITEM A (445/8912-V-01)
Criterion III of Appendix B to 10CFR Part 50,~as implemented by Section 3.0, Revision 0 of the'TU Electric Quality Assurance Manual., states, in part,
" Meas'ures sha11' also be' established for the selection-and review for suitability' of application.of materials, parts, equipment, and processes that are essential to the safety-related functions of the structures, systems and
. components..."
Paragraph 6.3.c of ECE-5.19 Revision 2 states, in part, "The RE (Responsible Engineer) assigned to perform the review of the-vendor document shall ensure that the following items are considered as appropriate or applicable:.the material, equipment, document, Service or process is in compliance with CPSES
~ design requirements..."
Contrary to the above, snubbers were installed with low strength bolting that could have been'overstressed if subjected to the maximum allowable design load.
L RESPONSE TO NOTICE OF VIOLATION ITEM A (445/8912-V-01)
TU Electric agrees with the alleged violation and the requested information follows:
1.
Reason for Violation 1The verdor (NPSI) initially provided two types of snubber assemblies to CPSES during the construction phase. The two types of assemblies were identical except that one utilized low strength bolts for connecting the mechanical arrestor to the transition kit while the other type utilized high strength bolts.
NPSI did'not indicate that two different types of snubber assemblies had been provided.and transmitted Certified Design Report Summaries (CDRSs) based on the use of low strength bolts. CDRSs' contain ratea load data and are used to determine the proper size assembly for a particular application. Subsequently, NPSI discontinued supplying low strength bolt assemblies and transmitted new CDRSs based on the use of high strength bolts. The NPSI transmittal letter did not indicate a change in bolt strength as a reason for the new'CDRSs and stated that the new CDRSs were applicable to all items furnished to CPSES. NPSI overlooked the fact that CPSES had previously been supplied low strength bolt assemblies. The erroneous information provided by NPSI resulted in the misapplication of low strength bolt assemblies by CPSES engineering personnel.
l
[
.m_m i
?
'.,,.;. Attachment t.o TXX-89598
' August 22, 1989 Page.2 of 2 2.
Corrective Steos Taken and Results Achieved Deficiency Report C-88-01197 was written to document that low strength bolt assemblies had been installed based on CDRSs for high strength assemblies.
An evaluation was-performed that showed that' low strength-bolts in size 3 and size 10 assemblies could be overstressed if the assemblies were loaded to the rated load for high strength bolt assemblies. The other size assemblies that contained low strength bolts L,
were found to be capable of withstanding the rated load for high strength l
bolt assemblies without exceeding ASME code allowable stresses. The-evaluation also determined that although the low strength bolts in size 3
'and 10 assemblies could be overstressed when compared to ASME code criteria, their loading would be well below the bolts ultimate capacity and the snubbers would have performed their intended function during a i.
Although the evaluation showed that only bolts in size 3 and 10 snubber assemblies had the potential to exceed ASME code allowable stress, a
-Design Change Authorization (DCA) wcs issued to require that all sizes of NPSI mechanical snubbers utilize high strength bolts between the arrestor and transition kit. Based on this DCA, low strength buts are being
. replaced with high strength bolts in the affected Unit I and Common l
j snubbers.
Upon resu'mption of Unit 2 construction activities, the Unit 2 snubbers-E will be re-inspec.ed per procedure AQP 11-.3 (revised as described below) and low strength bolts will be replaced with high strength bolts.
3.
Corrective Steps Which Will Be Taken to Avoid Further Violations NPSI has been made. aware of its error and has transmitted m copriate documentation to correct the error.
As an added precaution, TU Electric has taken the following actions:
I 1)
A change has been issued to inspection procedure AQP 11.3 which requires QC inspectors to verify that only high strength bolts are used in the connection between the arrestor and the transition kit for NPSI snubber assemblics.
2)
A DCA was issued to the specification which contains the technical requirements for suppliers of safety related supports and snubbers.
The DCA requires the seller to specifically address the effects of changes to previously supplied material when CDRS, load data sheets, or other des 1gn data are submitted.
4.
Date When Full ComD11ance Will Be Achieved The completion of bolt replacement in Unit 1 and Common snubber j
assemblies is expected to occur no later than September 23, 1989.
The completion of bolt replacement in Unit 2 snubber assemblies will occur prior to Unit 2 fuel load.
_- _____---____--