IR 05000346/1979033
| ML19309B443 | |
| Person / Time | |
|---|---|
| Site: | Davis Besse  |
| Issue date: | 02/12/1980 |
| From: | Danielson D, Yin T NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III) |
| To: | |
| Shared Package | |
| ML19309B435 | List: |
| References | |
| 50-346-79-33, IEB-79-02, IEB-79-14, IEB-79-2, NUDOCS 8004040150 | |
| Download: ML19309B443 (6) | |
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g U.S. NUCLEAR REGULATORY COMMISSION
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OFFICE OF INSPECTION AND ENFORCEMENT
REGION III
Report _No. 50-346/79-33 Docket No. 50-346 License No. NPF-3 Licensee: Toledo Edison Company Edison Plaza 300 Madison Avenue Toledo, OH 43652 Facility Name:
Davis-Besse Nuclear Power Station, Unit 1 Inspection At: NRC Headquarters, Bethesda, Maryland; Davis-Besse site, Oak Harbor, Ohio, and the Corporate Office.
Inspection Conducted: November 21 and December 12-14, 1979.
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Inspector I. T. Yin N'4/ h l.i N $ t m a b l h w Approved By:
D. H. Danielson, Chief 9/i 3/ h'
Engineering Support Section 2 Inspection Summary Inspection on November 21, December 12-14, 1979, and January 25, 1980 (Report No. 50-346/79-33)
Areas p spected:
Inspection of RTD connection repair at Hot Leg risers; licensee implementation of IEB 79-02 and IEB 79-14; and snubber installa-tions. This inspection involved a total of 26 inspector-hours onsite, at
.the licensee. corporate office, and at the NRC office by one NRC inspector.
Results: No items of noncompliance or deviations were identified.
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DETAILS
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Persons Contacted-November 21, 1979 Meeting at IE:HQ Bethesda, Maryland
Toledo Edison Company (TEC0')
C. Mekbel, Senior Engineer Bechtel Power Corporation, Gaithersburg, MD (Bechtel)
J. C. Ventura, Assistant Project Engineer C. M. Foltyn, Plant' Design Supervisor J. M. Ogle, Civil Group Supervisor R. D. Kies, Senior Enginer, Plant' Design Group K. Lee, Civil Staff Supervisor T. C. Lacroix, Pipe Support Staff Supervisor USKRC H. J. Wong, IE:HQ I. T. Yin,'IE:RIII S. R. Fair, KRR: DOR H. Ashar, NRR:SD December 12-14, 1979 Inspection at the Site and Corporate Office-TECO
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T. Murray, DB-1 Plant Superintendent B. R. Beyer, DB-1 Assistant Plant Superintendent P. Carr, DB-1 Maintenance Engineer C. Mekbel, Senior Engineer Bechtel C. M. Foltyn, Plant Design Supervisor J. C. Ventura, Assistant Project Engineer Licensee Action on Previously Identified Items
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(Closed) Unresolved Item (346/79-11-04): Questionable snubber cold posi-
tion and hot position settings. The inspector reviewed a Bechtel letter to TECO, BT-8892, " Range of Acceptable Snubber Piston' Settings", dated
- July 11, 1979, and concurred with the Bechtel findings and disposition.
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Functional or Program Areas Inspected e
1.
Licensee Implementation of IEB 79-14 The inspector reviewed the Bechtel Procedure, PDP-3, " Evaluation Procedure for As-Built Configuration of Nuclear Safety Related Piping Components, IE Bulletin 79-14", Revision 0, dated November 8, 1979, and had no adverse comments. The adequacy of implementation of PDP-3 by the design engineers will be determined during a future inspection at the Bechtel ofi'ce.
The inspector also reviewed a Bechtel letter to TECO, BT-8943, dated July 28, 1979,- including, the attached (1) walkdown team list, (2)
walkdown team personnel work experience records, and (3) indoctrina-tion and training sest n agenda and attendee records and had no adverse comments.
2.
Licensee Implementation of IEB 79-02 The status of work required by IEB 79-02, Revision 2, dated December 7, 1979 are as follows:
Item 1 The generic base plate flexibility analysis and calculations done by Bechtel for TECO was reviewed and found generally acceptable during the November 21, 1979, meeting. The analysis is acceptable for those cases discussed in the generic submittal and assumptions (such as prying is neglible) would have to be supported for base plates sized and conditions not included in the generic submittal.
It was noted that the anchor bolt stiffness.value of 44 kips per inch in the generic submittal was for demonstration purposes only.
Items 2 and 3 A TECO letter to RIII, Serial No. 1-108, dated December 7, 1979, stated in the enclosed report that, "In the current design review, the existing pipe support installations are being evaluated for the following factors of safety:
a. four for wedge type anchor bolts and b. five for shell-type anchor bolts. These values apply to both service load conditions (i.e., thermal loads, deadweight loads, and operating basis earthquake loads) and faulted load conditions (i.e.,
loads caused by accident conditions (LOCA), safe shutdown earthquake loads, extreme environmental loads, or loads encountered only during testing.)"
Item 4 The question'on whether or not site shell type bolt test torque values could be obtained from sources outside the power plant was-discussed in the November 21, 1979, meeting.
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A testing program performed at the University of Tennessee to investi-
gate the torquetension relationship for self-drilling shell type expansion anchor bolts was presented by TECO and Bechtel. The tests at the University of Tennessee used a torque wrench and load cell arrangement to measure the induced bolt load at various torque values.
Because torquing of the shell type anchor bolts does not set the shell into the concrete, TECO felt that the torque data developed from other locations with different strength concrete was applicable for use at Davis-Besse. A summary of the University of Tennesse-data indicated that for the torque values used at Davis-Besse the achieved anchor bolt load was greater than the maximum allowable anchor bolt load.
Based on the testing results, the torque values used at Davis-Besse were found to be acceptable.
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However, there are still some remaining items that need further review and inspection as stated in a. and c. below:
a.
NRC:NRR will provide additional input on whether or not pre-loading of concrete anchor bolts is required for seismic re-straints, b.
The inspector selected at random six 1 1/4" wedge type anchor and torque tested them in accordance with the procedures. No failure was identified.
c.
In review of the document presented to the inspector, it was stated that among the total 4440 bolts, only 2522 (57%) had QC records indicating that lubricant was applied during installa-tion. The inspector stated that a separate sampling test program for the other 43% of wedge type anchor bolts that were without any QC records should be initiated by the licensee. This is an unresolved item. (346/79-33-0i)
Items 5 to 8 The inspector reviewed the licensee res xnse letter to R1II, Serial No. 1-108, dated December 7, 1979, and had no adverse ccmment. Site review of licensee implementation of these items will be conducted during a future inspection.
3.
Damage on the Hot Leg Nozzles TECO reported to RIII in December, 1979, that all four mounting bosses for the Resistance Temperature Detector (RTD) on the two 36" hot leg pipe risers at Floor Elevation 637' were damaged due to thermal growth inter-ference between the pipe whip restraints and the bosses. The re-solution was to modify the restraints and to revise the design of the nozzle configuration.
During the site visit, the inspector observed the repair work in progress, however, no design calculation for the nozzle repair was available during his review.
Subsequent to the inspection, design change documents, including material volume re-
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placement considerations and stress calculations per ASME Section III, for removal of the mounting bosses and drilling of a larger hole were forwarded to RIII for evaluation.
In review of the TECO sub-mittals and in discussion with the ASME Code Committee member relative to the acceptability of threaded hole on the process pipe and the seal welds on the branch connections, the inspector concluded that the measures taken by TECO were adequate.
4.
Pipe Whip Restraint Clearances As a result of the inspection into the interference problem between the RTD on the hot leg pipe risers and the pipe whip restraints, the licensee reported on December 28, 1979, that the gaps, as designed and constructed, between the reactor coolant system (RCS) hot leg
_ piping and six of twelve pipe whip restraints were not in accordance with the assumption used in the RCS piping seismic analysis.
In the event of a seismic occurence, the movement would not have b'en as assumed in the analysis. As found clearances between the whip restraints and hot leg piping were in the order of zero to 1/4 inch. Minimam design clearances are 5/16 to 11/32 inch. The gap clearance problems were in the north-south direction only and involved only the three wnip restraints (bottom, middle, and top) on the vertical section of each hot leg (from reactor vessel to the top of the steam generator). The corrective measures were taken prior to startup.
During the January 25, 1980, telephone exit conference, the inspector stated all pipe restraint clearances should be measured during the next plant refueling outage as a part of IEB 79-14 inspection require-ments. This is an unresolved item (346/79-33-02).
5.
Snubber Deficiencies The piston rod wiper seals on four of the six large bore ITT-Grinnell a.
(ITT-G) steam generator snubbers were observed damage 1, and some indicated slight leaks. The inspector stated that problems should be corrected prior to plant startup.
Followup review and observation will be performed by the inspector.
This is an unresolved item.
(346/79-33-03).
b.
The ITT-G hydraulic pipe snubber, No. CCB-16-H6, installed on tha reactor coolant drain system was observed leaking heavily.
Followup observation of the licensee repair will be performed by the inspector. This is an unresolved item.
(346/79-33-04).
Unresolved Items Unresolved items are matters about which more information is equired in order to ascertain whether they are acceptable items, items o f non. orpli-ance or deviations. Unresolved items disclosed d'aring this visre e: ion are discussed in Paragraphs 2, 4, 5.a., and 5.b.
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Exit Interview
The inspector summarized the scope and findings of the inspection during t
a telephone conversation with Messrs. C. R. Domeck and C. Mekbel on January 25, 1980. The licensee acknowledged the findings reported herein.
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