ML20087A254
| ML20087A254 | |
| Person / Time | |
|---|---|
| Site: | Brunswick  |
| Issue date: | 01/03/1992 |
| From: | Spencer J CAROLINA POWER & LIGHT CO. |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| NUDOCS 9201080294 | |
| Download: ML20087A254 (6) | |
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s CP&L MfidAEllGMilLM22lr313HIPTemmwmn Carolina Power 8 Ught Company tantauwassswacar.nwnuamea Brunswick Nuclear Project c omvan, com.sponoe, t e P. O. Box 10429 Southport, N.C.
28461 0429 JA!i a riR FILE:
B09-135100 10CFR2.201 U.S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, D. C. 20555 BRUNSWICK STEAM ELECTRIC PINJT UNITS 1 & 2 DOCKET NOS. 50 325 6 50 324 LICENSE NOS. DPR 716 DPR 72 BEPLY TO A NOTICE OF VIO1ATION Contlemen:
The Brunswick Steam Electric Plant (BSEP) has received NRC Inspection Report 50 325/91 32 and 50 324/91-32 and finds that it does not contain information of a proprietary nature. This report included a Notice of Violation.
Enclosed is Carolina Power & Lib.t Company's response to that Notice of Violation.
Very truly yours.
t-('.w:)
s J. W. Spencer, Ceneral Manager Brunswick Nuclear Project RSK/
Enclosure cc:
Mr. S. D. Ebneter Mr. N. B. Le BSEP NRC Resident Office r
0 xmo n m o,C K M O O g I
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REA50?LfDR_ELyJ9t ATION;_.
The origin of the " manufacturers required maximum gap of 1/16" to 1/8""
referenced in the inspection report is unclear to CP&L.
Subsequent to the inspection, Brunswick requested that the vendor provide a recommendation for gap tolerance, initially, the vendor indicated that there were no end user tolerances for installation. Eventually, manufacturing tolerances i
were provided which are being evaluateu by the Nuclear Engineering Department for installation applicability. Sint.e there is a question about the installation maximum gap tolerance requirement, there appears to be no currently acceptable basis for incorporation of a.;pecific inspection criterion into our procedures at this time.
The programs currently in place are adequate to address the problem of bushing disengagement. These include two inservice inspection (ISI) programs and an as-built program, along with continuous plant modification work. These programs have resulted in a process of bushing engagement checks and repairs when appropriate.
ISI is required to inspect Class 1, 2 and 3 pipe supports within a 10 year period. There have been no loose bushings documented on Class 1, 2 or 3 struts as a result of these inspections.
The ISI snubber program inspections include a comprehensive overall visual inspection of snubbers for any service induced problems, including binding or bushing disengagement. As a result of this program, only twelve snubbers were found to-have loose bushings out of 1428 inspected during the last three refueling outages. Work orders were initiated to stake the loose bushings. This action is complete.
The Piping Design Turnover Program includes the support as-built process by the Nuclear Engineering Department. Although a check of washer and bushing placement was not a specified part of th!, as-built process, any problems noted with the strut or snubber attachments are documented by work orders. One pipe support with a fully diseagaged bushing was documented. Note that this support had welded washers and therefore missing washers did not contribute to bushing disengagement.
Based on tht above and historical data, Brunswick has a high level of confidence that the strut and snubber assemblies have not been functionally impaired and that they meet the safety requirements within industry standards.
CORRECTIVE STEPS WHICH HAVE BEEN TAKEN AND RESULTS ACHIEVED 1 None required.
CORRECTIVE STEPS WHICH WILL BE TAKEN TO AVOID FURTHER VIOLATIONS:
None required.
i DALE VHEN FULL COMPLIANCE WILL BE ACHIEVED:
CP&L is in full compliance.
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ENCLOSURE BRUNSWICK STEAM ELECIRIC PLANT, UNITS 1 & 2 NRC DOCKET NOS. 50-325, 50-324 OPERATING LICENSE NOS. DPR-71, DPR-62 REPLY TO NOTICE OF VIOLATION VIOLATION Violation B T.S. 6.8.1 requires that writtet proced as be established, implemented, and maintained for activities referenced in Appendix A of Reg. Guide 1.33, Rev. 2.
Appendix A states that specific procedures should be written for surveillance tests and inspections.
Contrary to the above, procedures PT-19.6,0A, PT-19.6,0B, PT-19.6.1, and PT-91.0.52 do not contain adequate inspection methods and criteria to check and verify that the gtp between the spacer-washer and the bushing-bearing for snubber and sway strut connections do not exceed 4 :' manufacturers required maxiraum gap examples of excessive gaps, up to of 1/16" and 1/8" during ISI inspection:
3/4", were discovered.
This is a Severity Level IV violation.
This violation applies to Units 1 & 2.
RESPONSE TO VJDLATION:
Admission or Denial of Violation:
e CP&L contests this violation. This position is based on the apparent lack of recommended vendor inspection criteria for the maxinum gap requirements at the time of the NRC inspection as stated in the notice of violation.
QELCTIVE ACTIONS _WHICH WILL B,E TAKEN TO AVOID FURTHER VIOLATIONS; The appropriate procedures used for the snubber support / pipe support ir.pections will be revised. This revision will include guidance such that when inspections are performed on pipe supports /inubber supports, the inspector will ensure that the bolted portion of a pipe clamp connection will be available for hands on inspection (including insulation removal).
Carolina Power & Light will request an ASME code interpretation as a means to clarify whether or not the entire c1 cmp is required to be inspected as a part of a complete Section XI support examination and to disseminate the information throughout the industry.
Based on the data obtained from the reinspections performed during the 1991 Unit 2 refueling outage (no inoperable supports found), the bolted connections on Units 1 and 2 will be inspected as normally scheduled per the ASME Section XI inspection plan.
DATE WHEN FULL COMPLIANCE WILL BE ACHIEVED:
Brunswick will be in compliance based on the ASME section XI support inspection scheduling. Both units' inspections are cheduled to be completed by the end of the second ISI interval which ends July 10, 1996.
REASON FOR THE VIOLATION:
lWF 1300(c) states that "the boundary of a nonintegt al supprrt connected +o a pressure retaining component is the contact surface between the component and the 3.jpport".
Section IWF-1300.A(e) states that *Wher9 the muchanical connection of a nonintegral support is buried within the component insulation, the support baandary may extend from the surface of the component insulation provided the support either carries the weight of the component or serves as a structural restraint in compression". This code exemption does not state that the only function of the supports / snubbers in question must be either compression loading or dead loading. CP&L interpreted the code to mean that if it can be shown that the snubbtr/ support is designed for compressive loading or dead weight support at any time during-its operating life, then removal of the insulation is not required.
During the Unit 2 refueling outage which ended in December,.951, the insulation covering the contact surface between the supports and pipes for 12 supports was not removed during 151 inspection based on CP&L's interpretation of the code. It should be noted that there are other utilities who interpret the code in this way. During their ISI inspection cond' acted during October 21-E5, 1991, the NRC determined that incomplete inspections were conducted in that the bolt connections covered by the insulation were not inspected.
COMECTIVE STt'PS WHICH HAVE BEEN TAKEN AND RESULTS ACHIEVED:
Following the NRC inspection, JP&L determined that its own interpretation was in error to the extent that the bolted -connections associated with pipe clamas should be inspected. The insulated pipe supports were reinspected prior to tie end of the recently completed Ur't 2 outage. The re.nspection included removal of_ insulation to perform a hands-on inspection of the bolted portion of the pipe clamp connection.
The results were as follows:
125 bolted connections were inspected.
Ninety-one of the 125 bo1+.ed connections inspected required insulation removal to inspect the bolting.
L Out of the total inspected, four exhibited loose primary nut bolting and one had a loose locknut.
Only _one of the five was considered a reNvant condition requiring engineering to perform an operability assessment.11 was determined to be operable.
A sample of ten pipe supports had insulation completely removed for clamp inspection. No relevant indications were found.
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ENCLOSUPE BRUNSWJCK STEAM ELECTRIC PLANT, UNITS 1 & 2 NGC DOCKET NOS. 50-323, 50-324 OPERATING LICENSE NOS. DPR 71, DPR-62 REPLY TO NOTICE OF VIOLATION VIOLATION Violation A 10CFR 50.55a.(g).(4) requires that throughout the service life of a boiling or pressurized water-cooled nuclear power facility, components (including supports) shall meet the requirements set forth in Section XI of the ASME Boiler and Pressure Vessel Code. The applicable edition of the Code, the 1980 Edition with Winter 1981 Addenda, for 151 inspection and testing, contains the following requirements:
IWA-2214 requires that VT-4 visual examinations shall be conducted on component supports.
IWF-1300.(c) states that the boundary of a nonintegral support connected to a pressure retaining component is the contact surfac? between the component and the support.
Contrary to the above, during the current refueling outage ISI inspection, the insulation covering the contact surface between the supports and pipe for Support hos. 25W 106SS212, 2PSN-83SS42, 2PSN-B3SS44, 2PSN B3SS46, 2PSN 83SS48, 2PSN-B5SSS1, 11-ISS305, 2 Ell-ISS306, 2 Ell-90SS267, 2 Ell-90SS268, 2 Ell-90SS271, and 2ft i 901 V 8 was not removed during ISI inspection. Because of this, incomplete 1: ;ps :a.o were conducted, in that critical support parts (including bolted co,,e
- e is) buried within the insulation were not inspected.
This is a Severity level IV violation.
l This violation applies to Units 1 & 2.
l RESPONSE TO V10LATION1 Admission or Denial of Violation:
CP&L admits to this violation.
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