ML20101R016
| ML20101R016 | |
| Person / Time | |
|---|---|
| Site: | Crane  |
| Issue date: | 04/10/1996 |
| From: | James Knubel GENERAL PUBLIC UTILITIES CORP. |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| 6710-96-2024, NUDOCS 9604160001 | |
| Download: ML20101R016 (8) | |
Text
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GPU Nuclear Corporation Nuclear an:ntra Middletown, Pennsylvania 17057-0480 (717)944 7621 Writer's Direct Dial Number:
(717) 948-8005 6710-96-2024 April 10,1996 U. S. Nuclear Regulatory Commission Attn: Document Contml Desk Washington, D. C. 20555 Gentlemen:
Subject:
nme Mile Island Nuclear Station, Unit 1 (TMI-1)
Operating License No. DPR-50 Docket No. 50-289 Response to Notice of Violation
Reference:
NRC Ietter dated March 11,1996, " Notice of Violation (NRC Inspection Report No. 50289/95-16)".
De mferenced letter enclosed a Notice of Violation containing two violations and states that
"..the first violation involved GPUN's failum to contml adequately a modification to the RCS drain line piping" and the "...second violation occurmd wl.en GPUN perfomied a more mfined ASME Section III calculation to disposition the pipe overstmss condition calculated in the 1990 B31.1 analysis".
Pursuant to the pmvisions of 10 CFR 2.201, Attachment I to this letter pmvides the GPU Nuclear response to each of the two violations contained in the Notice of Violation.
- Sincemly, uo J. Knubel Vice Pmsident and Director,31I RTZ cc:
TMI Senior Resident Inspector TMI-1 Senior Pmject Manager yQQ7/3 Region Administrator
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9604160001 960410 PDR ADOCK 05000289 G
PDR I
GPU Nuclear Corporation is a subsidiary of General Pubhc Utet:es Corporation
i METROPOLITAN EDISON COMPANY JERSEY CENTRAL POWER AND IlGHT COMPANY PENNSYLVANIA ELECTRICAL COMPANY GPU NUCLEAR CORPORATION 1
Thme Mile Island Nuclear Station, Unit 1 (TMI-1)
Operating License No. DPR-50 Docket No. 50-289 Reply to Notice of Violation (NRC Inspection Report No. 50-289/95-16) transmitted by NRC Ietter dated March 11,1996.
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'Ihis letter is submitted in mply to the Notice of Violation (NRC Inspection Report No.
50-289/95-16) tansmitted by NRC Letter dated Mamh 11,1996 which mfers to the i
inspection conducted on September 25-29,1995, at the Thme Mile Island, Unit 1 Nuclear Station (TMI) facility and fmm October 10-11,1995, at the GPU Nuclear (GPUN) Office in Parsippany, New Jersey. All statements contained in this reply have bmn myiewed, and all such statements made and matten set forth themin am tme and cormet to tie best of my knowledge.
I-J. Knube Vice Pmsident and Director, 'IMI-l Signed and swom befom me this
/d day of 1996 i
/
/
Notary Public(
Nemo il Sea; Suzanna c. M k:otik, NMary Puuic t.ondondorry Try., cauphen Coun'y My Commiscion egires Nov. 22,1999 MemDer,Pennsyhanla Anoctahan of tetus J
, 6710-9,6-2123
' Attachthent 1.
Page1of6 ATTACHMENT I NOTICE OF VIOLATION (Violation A)
A.
10 CFR Pan 50, Appendix B, ' Quality Assurance Criteria for Nuclear Power Plants and Fuel Reprocessing Plants,"Section IU, tesign Control," requires, in pan, that measures be established for the identification and control of design interfaces and for coordination among participating design organizations.
Appendix B also requires, in pan, that licensees establish design control
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measures that pmvide for verifying or checking the design adequacy.
Contrary to the above, from 1990 through at least September 1995, measures were not established for the identification and control of design interfaces and for coordination among participating design organizations as required, nor did the licensee establish design control measures that provided for verifying or checking design adequacy.
- 1. Specifically, GPUN failed to control adequately a modification to the Reactor Coolant System (RCS) drain line piping. The modification was developed as a result of a 1990 GPUN structural analysis that demonstrated that the drain line piping was overstressed due to an improper suppon 4
configuration. The modification was described in a letter, dated August 27, 1990, transmitted from GPUN Headquarters in Parsippany, New Jersey to the TMI site. However, the modification was not implemented as of September 1995, and GPUN could provide no documentation to demonstrate i
that the modification was ever properly dispositioned.
- 2. GPUN's design verification process failed to identify a significant error in the 1990 analysis that resulted in underestimating the level of stress in the pipe. Specifically, the analysis indicated thermal expansion stresses I
approximately 4% above the allowables specified in the design code of record (USAS B31.1 1967). However, when the analytical error was corrected in 1995, the stmsses were approximately 100% above the code allowables. (01013).
This is a Severity Level HI violation (Supplement I).
, 6710-9.6-2123
' Attachinent 1 Page 2 of 6 GPU NUCLEAR RESPONSE TO THE NOTICE OF VIOLATION (Violation Al GPU Nuclear acknowledges that the violation occurred as stated in the notice of violation. The first part of the violation, i.e., Part 1, occurred because the recommendation was not captured in any fonnal tracking system and there was no follow-up action on the part of staff or cognizant management.
GPU Nuclear has implemented the following corrective actions for Part 1 of this violation:
1)
GPU Nuclear has implemented a modification to the RCS drain line supports which satisnes B31.1 Code mquirements.
2)
All individuals involved were counseled that a lack of follow up action leading to a proper disposition of the recommendation is not acceptable.
3)
Since 1990, the Pmject Approval and Management Process has been reengineered. Specifically, the process today requires that the responsible System Engineer be involved with all proposed modifications, and that the System Performance Team reviews all modifications involving multi-diciplinary reviews where and when appmpriate.
4)
Management has emphasized to the staff that proper close out of mcommendations is an essential part of the engineering process.
5)
With mspect to the practice of proposing modifications in informal communication systems, GPU Nuclear has conducted a search of documents generated by the Engineering and Design Department where such recommendations may have existed. In particular, all memoranda and Technical Data Repoits from the years 1988,1990 and 1993 were myiewed, as well as Technical Functions Assigned Action Items from 1990. In all, over 4,000 documents were reviewed. It has been concluded from this mview that the specific incident identified in the violation is an isolated case.
All the above actions have been completed as of the date of this response. GPU
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Nuclear believes the actions taken provide masonable assurance that a similar event will not occur in the future.
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6710-96-2123
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'Attachinent 1 Page 3 of 6 The second part of the violation, i.e. Part 2, occurred due to personnel errors on the part of the preparer and verifier of the calculation. The Mechan;ca1 Analysis Staff within GPU Nuclear, which performs the pipe stress analyses, is locatec in the corporate offices in j
Parsippany, NJ. In 1995 the group consisted of five engineers with an average of 20 years nuclear experience. Four of the five engineers hold Masters Degrees and four hold a Professional Engineer License. The engineer tyho prepared the calculation and the engineer who verified the calculation are and were technically qualified to perform their f
functions.
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GPU Nuclear identified this error during its investigation of the crack in the drain line during the Three Mile Island Unit 1 Cycle 11 Refueling (llR) outage in 1995. As stated in the violation, when the specific error was corrected the calculated stresses were approximately 100% above the allowable specified in the design code of record (USAS B31.1 1967). That was an interim result. Fuither analyses, which more accurately represent the actual conditions for the pipe, conclude that the stmsses were 40% above the allowable. These analyses also demonstrate that these stress conditions 4
were not contributory to the initiation or propagation of the crack. The modifications j
made during the last refueling outage have reduced these stresses to values well below j
code allowable.
GPU Nuclear has implemented the following corrective actions for Part 2 of this j
violation:
(1)
The individuals involved were counseled; the verifier was temporarily restricted from performing verifications until he was retrained on the enhanced design verification procedure; and management has emphasized that both the preparer and verifier of a calculation must perform their functions with appropriate focus on technical quality. Further, a sample of previous verifications performed by the verifier was reviewed. It has been concluded that the incident noted in the violation is isolated.
(2)
GPU Nuclear has reviewed the governing procedures in an effort to identify pmgrammatic issues that may have contributed to the cause of the calculation and verification error. Further, GPU Nuclear consulted with others in the industry including two utilities and two architect engineering companies to learn about other design verification programs and practices. Although GPU Nuclear j
has concluded that our existing procedures did not contribute to the cause of the incident cited in the viobtion, these procedures were updated and enhanced to provide more complete guidance and direction. The corporate headquarters engineering staff, including management, involved with design calculations and verification were retrained on the procedum enhancements.
All the above actions have been completed as of the date of this msponse GPU Nuclear believes the actions taken provide reasonable assurance that a si.nitar event will not occur in the future.
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6710-96-2123
, Attachment 1 Page 4 of 6 4
NOTICE OF VIOLATION (Violation B) i B.
10 CFR 50.55a, ' Codes and Standards", paragraph (g), inservice inspection requirements,"requims that licensees of nuclear power plants meet applicable criteria in Section XI, Division 1, of the American Society of Mechanical Engineers (ASME) Boiler and Pressure Vessel Code ' Rules for Inservice Inspection of Nuclear Power Plant Components." ASME Section XI requires, in part, that licensees perform inservice examinations of class I components, including suppons. If the components or supports do not meet the examination acceptance criteria,Section XI mquires that the licensee perform a repair or replacement, or perform further evaluation to demonstrate the adequacy of the components or supports.
j Contrary to the above, in 1988 and 1990, GPUN did not meet the applicable
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requirements in 10 CFR 50.55a, in that, during the performance of inservice inspection (ISI) examinations of pipe supports on the RCS dmin lines, a class I d
component, GPUN identified distorted supports and failed to repair or replace j
or perform an adequate evaluation to establish the adequacy of the piping and supports. GPUN performed a structural analysis of the drain lines that demonstrated that the configuration of the supports did not allow for adequate pipe thermal expansion. Consequently, stress levels in the drain line piping exceeded the allowable stress values specified in the piping design code of record, USAS B31.1-1967, ' Power Piping". GPUN utilized a later code, i
Section III subsection NB-3653.6, to disposition the overstressed piping.
Paragraph NCA-1140 of Section III allows the use of specific pmvisions of the code but requires that all related requirements be met. The analysis performed by GPUN did not incorporate all related requirements of NB-3653.6 and was inadequate to demonstrate the adequacy of the piping and associated supports.
J (02014).
This is a Severity Level IV violation (Supplement I).
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, 6710 9g 2123 Anachment 1 Page 5 of 6 i
4 GPU NUCI RAR RESPONSE TO THE NOTICE OF VIOLATION (Violation B)
GPU Nuclear acknowledges that the violation occurred as stated in the notice of violation. This violation consists of two pans, one relates to suppon inspections and evaluations performed in 1988 and 1990, and one relates to a pipe stmss calculation performed in 1990. The supports were evaluated under the ASME Section XI 1977 Code through the 1978 Summer Addenda. The acceptance standards portion of this code, Section IWF 3410, was in the course of preparation. Therefore, Engineering was requested to determine if the support configuration was acceptable for continued 1
service or required mpair, replacement or funher evaluation. Engineering determined 4
that since the observed distortions were minor, the suppons were acceptable as is and '
4 would perform their intended function. The engineer used his judgment based upon his l
knowledge of materials and the design conditions to arrive at his conclusion. GPU Nuclear maintains that the use of engineering judgment to evaluate existing conditions is acceptable and within the guidance of ASME Section XI 1978 and 1986 (the current t
3 version for TMI).
i The pipe stress analysis issue relates to the full use of the appropriate guidance in i
ASME III when evaluating an issue from a B31.1 analysis. GPU Nuclear agrees that not all related requirements were satisfied. This situation occurred because both the preparer and verifier were not fully aware of the relationship between the requirements of ASME III and B31.1.
As a matter of perspective, the applied number of thermal cycles for this pipe is 240.
If the B31.1 allowable stress had been met the allowable number of cycles per B31.1 would have been 7000. The overstress that the engineer was attempting to resolve was 4% beyond the B31.1 code allowable. Therefore it was his conclusion before he began the reconciliation, that the stresses would be acceptable because the difference in applied stmss vs. allowable stress was so small.
GPU Nuclear has implemented the following corrective actions for this violation:
- 1. The engineers involved were counseled that it is imperative that when issues are dispositioned, the technical logic leading to conclusions must be clearly documented.
- 2. Engineering and Design depanment management has emphasized to engineers that adherence to all relevant code provisions is required.
- 3. An outside consultant was retained to investigate and explain the issues in applying ASME III when evaluating a B31.1 analysis.
Y 6710-96-2123
'A'ttachInent 1 Page 6 of 6
- 4. The calculation procedure has been revised to ensure management concurrence is obtained when specialized methods are used to satisfy the design code of record, i.e., ASME Section III or B31.1 evaluations. Management has stressed that adherence to the design code of record is a design basis requirement.
- 5. GPU Nuclear reviewed the stress analysis f~iles and found no other instance where ASME III was used to reconcile design basis issues.
All the above actions have been completed. GPU Nuclear believes the actions taken provide reasonable assurance that a similar event will not occur in the future.
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