IR 05000237/1981030
| ML17194A307 | |
| Person / Time | |
|---|---|
| Site: | Dresden  |
| Issue date: | 11/18/1981 |
| From: | Danielson D, Yin I NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III) |
| To: | |
| Shared Package | |
| ML17194A306 | List: |
| References | |
| 50-237-81-30, IEB-79-14, NUDOCS 8112080398 | |
| Download: ML17194A307 (9) | |
Text
U.S. NUCLEAR REGULATORY COMMISSION
REGION III
Report No. 50-237/81-30 Docket No. 50-237
- Licensee:
Commonwealth Edison Company Post Office Box 767 Chicago, IL 60690 Facility Name:
Dresden Station, Unit 2 Inspection At:
Dresden Site, Morris, IL
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License No. DPR-19 Inspection Conduc.ted:
October 6-7,. 23, 27-:28., and November 4., 1981 r!JmL~::
Inspector~. T. Yin ~
Approved By: ~nielson, Chief Materials and Processes Inspection Summary
\\. '*
I I )t f')8"t Section Inspection on October 6-7, 23, 27-28,.and November 4, 1981 (Report N..,237/81-30)
Areas Inspected:
Inspection of CCSW Loop 2A suspension system damlge and observation of hardware repair to meet IEB 79-14 operability criteri Meeting with licensee to discuss long range system upgrade to FSAR require-ment The inspection involved 32 inspector-hours onsite by one NRC inspecto Results:
No items of noncompliance or deviations were identifie I..
PDR ADOCK 8 8l,1 l2s
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05000237
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DETAILS Persons Contacted Site Inspection on Ociober 6-7, 1981 Commonwealth Edison Company (CECo)
D. L. Farrar, Assistant Superintendent R. M. Ragan, Assistant Superintendent J. Brunner, Technical Staff NRC - RIII
.T. M. Tongue, Senior Resident Inspector Meeting at NRC - RiiI on October 23, 1981 CE Co
.L. 0. DelGeorge, Director of Nuclear Licensing J. D. Brunn.er, *Technical Staff Supervisor R. H. Mirochna, SNED Staff E. R.. Zebus, Prbject Engineer T. J. Rausch, Nuclear Licensing Staff EDS Nuclear S. M. Jaffer, Section Manager NRC -.RlII C. E. Norelius, Director, Division of Engineering and Technical Inspection
- C. C. Williams, Acting Chief, Engineering Inspecti6n Branch D. H. Danielson, Chief, Materials and Processes Section F. W. Reimann, Acting Chief, Reactor Projects Section IC
.M. J. Jordan, Resident Inspec;tor I. T. Yin, Reactor Inspectbr Site Inspection on October 27-28, 1981 CE Co D. J. Scott, Superintendent D. Farrar, Assistant Superintendent J. Brunner, Technical Staff Supervisor B. Rybak,* Systems Group Leader-.
P. Holland, Assistant Group* Leader W. E. McGee, Project Group Leader
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Site Inspection on November 4, 1981 CE Co
- * * * * Rybak, Systems Group Leader D. Brunner, Technical Staff Supervisor M. Ragan, Assistant Superintendent - Operations J. Scott, Station Superintendent F. Wilmere, Lead QA Inspector
- Denotes those attending the management exit meeting on November 4, 1981.
Eunctional or Program Areas Inspected During the IEB 79-14 walkdown ins.pection in the Dresden Unit 2 torus area on October 5, 1981, a number of hangers and restraints were observed damaged on.the Containment Cooling Service Water System Loop A (CCSW-2A).
The system was declared.to be inoperable on the same da This inspection documents inspection £iii.dings of the damaged hardware, short term repairs, and proposed long term corrective action * System Configuration The CCSW system reviewed by the inspector included the.8" nozzle connections to Containment Cooling Water Pumps 2A-1501-44 and 2B-1501-44 at elevation 496.25'. After the 8" elbow, the lines run vertically to elevation 506.75 with a 10 x 8 reducer, a 10" check valve, and a normally open gate ~alve ~n each of the two riser The two 2-1510-10" lines merge into one 2-1510-16" line running west for a short distance it elevation ~06.75'. The 2-1510-16" line runs up to elevation 542. 75'. The line runs in a generally west direction for approximately 85'
where Anchor SK-B-2-1510-36 was found damage The line then runs in a generally south direction for approximately 90' without any observed suspension hardware damag The line then drops to elevation 499' with a couple of offsets in between*.
Some structural concrete damage was observed at vertical rigid elbow hanger SK-B-2-1510-1 The line then runs in a generally south direction for approximately 140'.
Hangers and restraints on this section of the system included SK-B-2-1510-17 to - Damage was observed on some of these com-ponents.
- 3 - The line then runs in a generally east direction for approximately 90' before connecting to the Containment Cooling Heat Exchanger 2A-150 The line is inclined* to elevation 510. 75.' in the beginning of the ru A normally opened gate valve was installed before the heat exchange Hangers and restraints on this section of the system included SK"".B-2-1510-8 to *L Damage was observed on some of these component.
Observation of Damaged Support and Restraint Components on October 6, 1981 SK-B-2-1510-3 Chipped and cracked concrete at the embedded hanger attachment plat SK-B~2-1510-5 Same as a. Loose bolts on pipe clam SK-B-2-1510-7 Pipe clamp moved 2 1/2" from original vertical installation positio SK-B-2-1510-9 Pipe was not supported by the trapeze hange /4" gap was measure * SK"".B~2-1510-10 Reaction force of pipe movement against the torus vessel wall bent the hanger ro SK-B"".2-1510~11 Substantial amount of concrete chipping was observed at the embedded hanger attachment plat Gaps of approximately 1/4" were observe SK-B-2~1510-12 The restraint was completely pulled away from the wall leaving a cavity of approximately 1' :.. 6" x 4' x 2 1/2" on the concrete wall surfac No rebar was expose SK-B-2-1510-16 NO damage on the restrain The scrape marks.indicated a pipe movement of 1 1/2" on each side of the.restrain *
- SK-B-2-1510-17 Same as SK-B-2-1510-18 Same as SK-B~2-1510-36 B.roken grout was obsei:Ved on two of the four structural support bas.e.
Meeting at NRC-iUII A meeting was held at NRC-RIII o.ffice on October 23, 1981, to discuss long term r*epair for CCSW piping suspension system damag The agenda of the meeting is listed below and the licensee committed to provide RIII written schedules for the initiation and completion of the analyses, evaluation, and repair work activities by November 9, 198 Upgrading of CCSW loop 2A to FSAR requirement Completion of !EB 79-14 requirements for all safety related piping system Modification of CCSW loops 2B, 3A, and 3B to meet the FSAR requirement Prevention of further damage from hydro-dynamic shock induced from piping or heat exchanger drain down, check valve slam, and other possible transient event Fa,tigue evaluation of CCSW Loop 2A to demonstrate that long term operability of CCSW components has not been compromise.
O.bservation of System Repair On October 27~28_, 1981 the inspector observed the EDS recommended work performed on the following restraints and support Relocated approximately 52 inches from its original location with a different anchor bolt desig Redesigned, changed from U-bolt type to structural frame desig Repaired to its original operational conditio Cracked grout was removed and the voids were filled with hydraulic cemen (This item was not observed by the ;inspector.)
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The inspector stated that he was satisfied with the workmanship and construction complying with design requirements, bu:t had the following comments:
2-1510-5 The loose.ned bolts and nuts on pipe clamp were* not retightene The off-positioned pipe clamp was not returned to its original vertical positio The trapeze type support was not adjusted to carry piping dead load The above deficiencies were corrected by the licensee prior to the inspector's return visit on November 4, 198 See Paragraph 5 of this report for rework documentatio.
Review of *System Repair Records The inspector reviewed the following piping restraint and support repair, replacement, readjustment, and modification records:
Unit 2 CCSW Loop 2A Hanger N *2-1510-5 2-1510-7 2-1510-9 Unit 3 LPCI Hanger N Unit 3 SBLC Hanger N Work Request No., Date D16240, 10/5/ D16284, 10/8/81 D16285, 10/8/81 D16265, 10/7 /81 D11620, 10/29/81 D 11619 ' 10 I 2 9 I 81 D11618, 10/29/81 Work Request No., Date D16315, 10/10/81 Work Request Nq., Date D16313, 10/10/81 Work Completion Date 10/10/81 10/11/81 10/10/81 10/10/81 11/2/81 11/3/81 11/3/81 Work Completion Date 10/11/81 Work Completion Date 10/p/81 The inspector also reviewed the following design documents and inspection records:
EDS DCN D2-103, Revision 2, dated October 8, 1981', installatiqn requirements per 2-1510-1 *
Dresden Station Maintenance Procedure DMP 040-:101 Revision O, Table 3, "Minimum Embedded Le[lgth Requirement (Le)".
The 6" measured concrete embedment length for.. the 3/ 4" di'ameter bolts at 2-1510-13 was acceptabl The target desig!l minimum*
embedment length per EDS drawing DCN No. D2-102, Revision 1, dated October 8, 1981 was 8 3/8".
No items of noncompliance or deviations were identifie.
Review of Temporary Changes to Procedures The licensee evaluated the system operating dynamics including potential dynamic transients which may be induced by various sequences of pump.starts and trips from initially partially drained piping and made temporary changes to the following Dresden surveillance and operating procedure *
DOS 1500-3, "Containment Cooling Service Water Pump Test",
Revision 7, approved on October 14, 198 DOS 1500-4, "LPCI System Operability Test With the Torus Unavailable", Revision 5, approved on October 15, 198 DOS 1500-5, "LPCI System Quarterly Flow Rate Test", Revision 3, approved on October 15, 198 DOS 1500-6, "tPCI System Pump Operability Test with Torus Available", Revision 9, approved on October 15, 198 DOP 1500-2, "Suppression Pool Cooling Mode of L. P. Cooling System", Revision 4, approved on October 14, 198 DOP 1500-3, "Containment Spray Cooling Mode of L. P. Coolant Injection System", Revision 3, approved on October 15, 198 No items of noncompliance or deviations were identified as a result of the procedure revie.
Licensee Visual Inspection of Piping and Pipe Supports In accordance with the instruction stated in NRC-RIII Confirmatory Action Letter (CAL) dated October 9, 1981, the licensee performed visual inspection of the following accessible Unit 2 and Unit 3*
safety related systems to verify that piping and pipe supports were not significantly degraded or damaged:
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Isolation Condenser RWCU The task was completed on October 16, 1981, and a letter (DJS LTR:
81-825), was forwarded to RIII on the same day reporting no significant adverse finding The inspector reviewed the "Damaged Hanger Survey System Summary" sheets, including the following licensee identified deficiencies: LPCI, Hanger No. 1531-M-204, installed on*2-1531-18" line, reference drawing M-555, where concrete spalling.was foun The inspector observed the concrete damage, and considered it to be a part of the unresolved item discussed in Paragraph 8 of this repor SBLC, Hanger No. 3-4315-5, installed on 3-4315-2" and 3" lines, reference drawing 3-4315-IS0-1, where a bolt was missing at the pipe clam Repair was completed, see Paragraph 5 of this repor LPCI, Hanger No. 3-1533-9, installed on 3-1533-3" line, refer-ence drawing SKB-3-1533 A/B ISO*l, where a hanger rod was disconnected at the ceiling bracke The rod was re-connected, see Paragraph 5 of this repor No items of noncompliance or deviations were identifie.
EDS Analyses The EDS evaluation basis system stress analysis and component calcula-tions were not available for the inspector's review at the site. Future inspection at EDS is planned to review the following areas: Methodology to determine concrete acceptability for the spalled and cracked conditions ~iscussed in Paragraphs 2 and 7.a of this repor Piping stress analysis including modeling of the existing piping and pipe suspension system configuration.
. Component structural calculations, including CCSW-2-1510-12 where the number of concrete anchor bolts was significantly reduce R~lative to CCSW-2-1510-10 where a bent hanger rod was found, and.where the closest gap between the hanger and the torus was measured to be 1".
The basis for the acceptance and the
.piping displacements under OBE and SSE conditions will be reviewe =*. *_. *' v: Long range system e¥aluation discussed in Paragraph 3 of this repor This is considered to be an unresolved item (237/81-30-01)..NRC-RIII Confirmatory Action Letter (CAL)
A CAL, dated October 9, 1981 (Exhibit A) was issued to the license The basis of the CAL was primarily based on the inspections performed on October 6-7, 1981, as discussed in Paragraphs 1 ~nd 2 of this repor The status of licensee action per the CAL is as follows:
Item 1.a:
Followup inspection was performed on October 27-28 and November 4, 198 Findings are documented in Paragraphs 4 and 5 of this repor Item 1. b:
Followup inspection was performed on Oct6ber 27-28, 198 Findings are documented in Paragraph 6 of this repor Item 1.c:
The inspector reviewed the licensee letter (DJS LTR 81-816)
to RIII, dated October 13, 1981, and had no adverse commen The licensee letter is included in Exhibit Item 2:
Followup inspection was performed on October 27-28, 198 Findings are documented in Paragraphs 5 and 7 of this repor No items of noncompliance or deviatipns were identified as a result of the observations and review of record The licensee fulfilled the requirements stated in Items 1 and 2 of the CA Unresolved Items Unresolved items are matters about which more information is required in order to ascertain whether they are acceptable items, items of noncompliance, or deviation The unresolved item disclosed during this inspection is discussed in Paragraph Exit Interview Th~ inspector met with licensee representatives at the conclusion of th~
inspection on November 4, 198 The inspector summarized the scope and
- findings of the inspectio The licensee acknowledged the findings reported herei