ML17179A665
| ML17179A665 | |
| Person / Time | |
|---|---|
| Site: | Dresden  |
| Issue date: | 12/24/1992 |
| From: | Hiland P NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III) |
| To: | |
| Shared Package | |
| ML17179A663 | List: |
| References | |
| 50-237-92-35, NUDOCS 9301050100 | |
| Download: ML17179A665 (5) | |
See also: IR 05000237/1992035
Text
U.S. NUCLEAR REGULATORY COMMISSION
REGION III
Report No. * 50-237 /92035(0RP)
- ~ocket*No. 50-237 * *
Licensee:
Commonwealth Edison Company
Opus West .. I I I
1400 Opus Place
. Downers Grove~ IL
60515
Facility Name:
Dresden Nuclear Power Station, Unit 2
Inspection At:\\
Dresd~n-Site, Horris, Illinois
Inspection Conducted: October 19 through December 15, 1992
License No. OPR..:.19
Inspector:
- V. P. Lougheed
Approved By: ~~;2_ *
. -DEC 2 1:. 'i392
~trick L. Hiland, Chief
Reactor Projects Section 18
Inspection Summary
Date
Inspection from October 19 through December 15. 1992 (Report No.*
50-237/92035CDRP)
Areas Inspected: This was a special, unannounced safety inspection by a
regional based inspector to review the events surrounding the licensee's
identification that t~chnical specifi~ati6n (TS) Figure 3.6.l was incorrect
due to inaccurate information being* supplied to the Commission as part of the
amendment request.
Inspection module 92701 was used during this inspection;.
Results:* One apparent violation.of 10.CFR 50.9 was identified. That*
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regulation requires that. infotrnation_provided to the-conrnission be complete-
and accurate in all respects.
9301050100921224
ADOCK 05000237
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- DETAILS
1.
Persons Contacted
Commc>nwea 1th 'Edi son Company .(CECo)
- *R. Fl ah i ve, T echn i ca 1 Superi nten.dent
. *T. O'Conner, Assistant Superinten~ent - Maintenance
- M. Strait, Technkal Staff Supervisor
- R~ Radtke, Regulatory Assurance Supervisor
- E. *carro 11, NRC Coordi.nator, Regulatory Assurance
- D. SaccQmando, Nuclear Licensing Engineer.
P. Piet, Nuclear Licensing Admh1istrator
T.* Spry, Engineer, Nuclear Engineering Department
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. U.S. Nuclear Re.gulatory Cormnissjon *
- P. Hiland, Chief, Reactor Projects Section 18 *
- W. Rogers; Senio~ Resident Inspe~tor
- M. Peck, ~esident Inspector
- A. M. Stone, Resident Inspector
- Denotes.those attending the exit meeting ori December 15, 1993.
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The i nspector*s al so talked with or interviewed several other licensee *
emp l oy~es during the course of the inspect iOn.. .
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2~
Licensee Event ~eport.Follow-yp
(Closed} Licerisee Event Re~ort 237-92020 "Unit 2 Reactor Vessel Excieded
. Design Basis Due to Non-Conservative Pressure-Temperature Curve."
Review of-this item is presented below.
- 3.
Regylatory Regyire!nent. Appar*ent Yiolatjon. and pyratjon -*
On October 23, 1989; the licensee submitted a Unit 2 Techni.cal
- Specification* (TS} amendment request which**was not accurate in all
respects.
In this amendment, the lttensee attested that sufficient
information existed ori th~ material properties of the-Unit 2 reactor
vessel which justifie(j.1owering the reference nil-ductHity transition
temperature described in TS Figure 3.6.1. The Ts* amendment request was
granted on September 5, 1991.
On June 26, 1992~ the licen-see identified
that the material properties _used in the TS amendment request were * *
incorrect. Th'is is an apparent violation of 10 CFR 50.9 which requires
.that foformation provided to the Convnission by a-licensee be complete
and accurate in all respects. (237/92035-0l(DRP~ The. apparent violati.on, which was an isolated example, occurred when the licensee. provided inaccurate information to the NRC. * 4. Root Cause In discussions with cognizant licensee individuals, the inspector idenfffi ea- the l ikii.V-~root caus*e of tlliS' -spe'C-ffi c ~viol atf6n"'to~-*be . insufficient management oversight 9f ~ontractor employees. Sufficient
5. 6. . . oversight was "not provided to the contract employee who.first di-scerned a difference in the Dresden Unit 2 reactor vessel material properties as compared to the Unit 3 vessel, or eith~r v~ssel at Quad Cities.* *Had
overs-ight been provided, the information might have been invalidated at . that* time, rather than three Years later .. SecQnd, insuffici~nt
oversight was provided when the contractor informally transmitted the presumed Unit 2 material properties to GE, and when GE used these properties in their calculation. Had management rev.iewed the inputs to the GE calculation, *and questioned their validity, then the incorrect assumptions might h~ve been identif-iedprior to the amendment being submitted. An additional causal factor was the .inadequat~ review performed on the TS submittal which failed to identify that the submittal. contained inaccurate information. *
Identification .and Report'ability of the Apparent Violation 6n June 26, 1992,.duri~g a review of the detailed fabrication records (i~ preparation of a response to Generic Letter 92-01), a licensee engineer identified that the material prope~ties .and initial reference n11-ductility temperature provided for the Unit 2 pressure-temperature curve were incorrect *. This engineer promptly notifi~d the stati~n of
- the finding; in turn, the station promptly notified the NRC *. The
inaccurate technical specificat.ion resulted in the plant being in a ccindition that *is outside the design basi~ .of the plant. This ls reportable within one hour under the requirements of 10 CFR 50.72. * The - licensee complied with thi~*requirement, and the report was complet~ and
- accurate about the previous inatcuracies.
Opportuniti~s for Prior Identification on*November 1, 1990l the li~ensee received detailed fabrication records- from the ve~sel manufacturer through GE for all the Dresden and Quad Cities reactor vessels. *These records were obtained so that the
licensee could attempt to reduce the reference nil-ductility value for Dresden Unit 3 and for Quad. However, the records were not reviewed unt i 1 June* 1992, when -the 1 i censee was performing a rev.i ew * for Generic: Letter 92-01. 7. Saf~ty Significance The inspector identified two safety ~ignificant concerns with the apparent violation. First, the inac.curate informatfon dfrectly led to a
- regulatory decision (i.e. gr~riti'1g a requested technical specification
amendment.) .Had the NRC known that the Dresden Unit 2 reactor vess~l materi.al properties claimed in the amendment request were ~ncorrect~ the am~ndment.would not have been ~ranted.
. - Second, use of the inaccurate technical specification figure could h~ve affected th~ Unit 2 reactor vessel integrity. During the ten months that the amendment reques~ was in effect, tw9 bolt ups and two * hydrostatic tests were performed. Both of the bolt ups and one of the hydrostat~c tests were done at a inore*conservative temperature, *because -- -- --*- - - 2
~ the licensee's procedures* had not been revised prior to these activities occurring. The licensee evaluated th~ effects of the second hydrostatic test being performed under the non-conservative Unit .2 curve and
concluded that vessel integrity was not impacted. The inspector agreed
- with this conclusion, based on review of the*operability evaluation.
However,* the potential existed for future* bolt ups and hydrostatic tests to have been performed using the non-conservative .. technical specification figure, which might have resulted in reactor vessel
- integrity problems.
8. Programmatk Concerns The inspector did not identify any other cases where a licensee
- amendment request contained inaccurate information.
However, the 1 ast two systematic assessment of .licensee performance {SALP) reports mentioned concerns with engineering management oversight of contractor --activities. Thi.s engineering management weakness was considered by the inspector to be a contributor to the violation~
. 9. Short-term C6rrectiv~ Actions. The inspector confirmed that the 1 icensee took ap*propriate~ immediate corrective action~ to ensure that the non~conservative turve was not.
- used. :Additiorially, ~n September 16, 1992, a new amendment request was
submitted to.the NRC to correct the Dresden Unit 2. technical specification* Figure 3.6 .* 1. - This request w*as under review at the end of the-inspection. The licensee also temporarily revised a number9f procedures which re,ferenced the incorrect technical specification figure * and committed to make permanent revisions in early 1993. These immedjate actions. were t~ken without any need for. NRC intervention and were appropriate and complete.
-10. Seguenc~ of Events Concerning the Iticorrect Non-Conservative*Pressure- Temperature Curve
In October 1988,. as part*of the licensee's efforts to respond to Genericr letter 88-11 and Regulatory Guide 1.99, revision 2, a contractor*.* employee reviewed summary documents which described weld procedures *and other records used in fabrication of the reactor vessels for-Dresden and Quad Ciths. This employee, working closely with the General Electric * Company {GE) concluded that the electroslag weld material used on the Dresden Unit 2 reactor vessel was different from that used on Dresden Unit 3 or eit.her unit at Quad Cities. The employee documented this* conclusion in an October 19,* 1988, letter to Commonwealth Edison titled
- "Impact of Reg. Guide 1.99 Rev. 2 and Generic Letter 88-11 on
Commonwealth Edison's Operating Units." * In August 1989, GE revised the pressure-temperature curves for both units at Dresden and Quad Cities in order to comply with Regulatory * Guide 1.99, Revision 2. A Dresden Unit 2 specific pressure-temperature curve was developed, based on the *October 19, 1988 letter de~cribed .above. A more generic curve was _develo~~d for Dresd~~- ~-~it 3 a_n~ b?_th
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.** units at Quad Cities, based on weld test sample materials. *The revised pressure temperature curves were supplied to the Conunonwealth Edison
- Company (CECo) via report SASR 89-54 *PRESSURE~TEMPERATURE CURVES PER
REGULATORY GUIDE 1.99, REVISION 2 FOR THE DRESDEN AND QUAD CITIES NUCLEAR POWER STATIONS,* Revision l~ dated Aug~st 1989.- - . . .
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. . . . . On.October 23, 1989, the licensee submitted a techniC .. l specification ~mendment request for both units at Dresden and Quad Cit.ies Nuclear_. Power Stations. .These amendment requests revised the pressure'.'"- temperature curves for .all four ~nits. The Dresden Unit 2 curve was specifically separated from the other curves for the three units, based on the above GE report.
On March 23, 1990, the licensee provided additional .. information supporting the amendment request, including additional information in support of the- Unit 2 specific curves.
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On September 5, 1991, the ColTllTii ssi.on granted the requested_ amendment (Amendment 114 for Unft 2). . . . On June 26, 1992~ during a review of detailed fabrication records (in preparation of~ response to Generic Letter 92-01), a licensee engineer*
- identified that the material properties and initial reference nil~
.. ductility* temperature provided for the Unit 2 pressure-temperature curve were incorrect.
on July 16, 1992~ the 1 icensee submitted a 1 icensee ;event report which identified that, on one occasion, th~ tempe~ature wa~ below the* conse~vative Unit.3 ctirv~, although it was within the Unit 2 * .. requirements. The licensee's operability determinatfon concluded that
- the deviation was not great enough to affect the reactor vessel
integrity~
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On September 14, 1992, the licensee submitted a new amendment request t6 revise the Unit 2 pressure-tem~erature curve to duplicate the Unit 3 curve. This amendment request was under review a~ of the end of the inspection* period.
11. Exit Meeting The inspectors met with the li~ensee representatives denoted in paragraph.I during the inspection period and at the conclusion of the inspection on December 15, 1992. The inspectors sununarized the scope and results of the inspection and discussed the likely content of this inspection report. _The licensee acknowledged the apparent violation an~. did not.indicate that there was any disagreement with the* ~haract*rizatioti of the apparent violation. The licensee did not constde.r any of the information ,disclosed during the inspection as proprietary in nature.
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