ML20004D893
| ML20004D893 | |
| Person / Time | |
|---|---|
| Site: | Wolf Creek, Callaway  |
| Issue date: | 06/05/1981 |
| From: | Seiken S STANDARDIZED NUCLEAR UNIT POWER PLANT SYSTEM |
| To: | James Keppler, Seyfrit K NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III), NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION IV) |
| References | |
| 10CFR-050.55E, SLNRC-81-43, NUDOCS 8106100272 | |
| Download: ML20004D893 (25) | |
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\ 3, h June 5, 1981 is SLNRC 81-43 FILE: 0491.10.2/M-2028 SUBJ: Final Report on SNUPPS Pipe Whio Restraint Design Discrepancies:
SDR 81-2 Mr. James G. Keppler Director, Region III Office of Inspection and Enforcement U.S. Nuclear Regulatory Commission 799 Roosevelt Road Glen Ellyn, Illinois 60137 Mr. Karl Seyfrit
- Director, Region IV .
U.S. Nuclear Regulatory Commission Suite 1000, Parkway Central Plaza %, '
611 Ryan Plaza ~
Arlingtor, Texas 76012 Ref: 5.NiC 81-014 dtd. 3/14/81: Subj. as Above Gentlemen:
The reference letter forwarded to NRC, an interim report concerning discrepancies in the design of SNUPPS standard power block pipe whip restraints. The purpose of this letter is to provide to the NRC, pur-suant to 10CFR50.55(e), a final report regarding the design discrepan-cies including follow-up actions being taken by the Arch'tect/ Engineer, Bechtel Power Corporation, to resolve such discrepancie',. As previoud y indicated, this report and the actions indicated therein arc generic to SNUPPS and therefore applicable to Callaway Nos. I anj 2 and Wolf Creek units.
The enclosed report outlines actions taken to re-examine and, in certain instances, to modify the design cf a numoer of the pipe whip restraints.
Additionally, other restraints are in the process of being re-examined and may also require design modifications including possible field modifica-tions. The status of the follow-up actions and the final resolution of all defined discrepancies will be documented by Bechtel
- SNUPPS and the results made available at the jobsite for NRC review and evaluation, as required.
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SLNRC 81-43 Page Two If you have further questions concerning this matter, please contact the undersigned.
Very truly yours, S. . Seiken Quality Assurance Manager SJS:dck:8a8 Encl. Report SDR 81-2 cc: G. L. Koester, KGE D. T. McPhee, KCPL J. K. Bryan, UE W. Hansen, NRC/Callaway I T. Vandel, NRC Wolf Creek ss ss ,J. Konklin, NRC Region III Victor Stello, Jr. Director, Office of I&E, USNRC, _
Washington, D.C.
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4' h I FINAL REPORT i -
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- PIPE-WHIP RESTRAINT' DESIGN DISCREPANCIES PER- ,
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j' SNUPPS Project Bechtel Power' Corporation i- . .
Gaithersburg, Maryland .
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TABLE OF CONTENTS Page 1
I. Introduction Description of Restrait.t Design 3 II.
6 III. Description of The Design Discrepancies 8
IV . Analysis of Safety Implications 9
V. Method of Resolution 11 VI. Conclusions 11 VII. Correctiv Action VIII. Appendices ,
A. Correspondence i
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4 I. INTRODUCTICN
.During an internal design review of the SNUPPS " Design Guide for Pipe Whip Restraints," a discrepancy was identified between the SNUPPS " Design Guide for Pipe Whip Restraints" cad Bechtel'- N-TOP-2, Design for Pipe Break Effects. This discrepancy involved the absence in the resign Guide of the requirement for an energy balance analysis for the design of pipe whip restraints in thw cases where the formation of a plastic moment in the pipe could not be prevented. This is contrary to the requirements of BN-TOP-2, the governing design criteria f or pipe break ef fects, which requires that energy balance techniques be used . .
The restraints in question utilize an energy absorbing device (either a i
stainless steel honeycomb material or specially designed upset U-bolts) attached to a steel substructure. It was also discovered that in some --res a SNUPPS Design Guide requirement to design the restraint substructure to an upper bound load of the energy absorbing device was not fulfilled. Instances were found where either the energy absorbing material (EAM) cross-sectional dimensions or U-bolt diamete- were increased in size above their design require-ment to round-off their dimensions without providing a corresponding increase in the restraint substructure capacity. This rounding-off of material size resulted 1
in additional capacity in the energy absorbing device over and above that required by analysis, but also resulted in an effective reduction in the required design margin between the restraint substructure ard the energy absorbing device. The restraint substructures, therefore, were not designed for the upper bound load of the energy absorbing device in these instances. -
At de time the above discrepancies were identified, 242 restraints were issued for construction. Of these,103 were affected by the above discrepancies.
A third concern was identified involving the design of the restraint sub-s tructure. As indicated above, the restraint substructures were designed for upper limit loads which may be imposed by the energy absorbing device.
However, this criteria does not conservatively take into account the dynamic nature of the load suddenly applied to the steel restraint substructures by the energy absorbing device.
On December 24, 1980, the NRC, Region 1, was informed b3 the SNUPPS QA Manager of a potential generic deficiency in the analytical techniques used by Bechtel in the design of pipe whip restraints for the SNUPPS standard power block. This was followed by a letter to the NP.C on January 23, 1981. Subsequent to this, a letter was written to the NRC on March 16, 1981, identifying the problem in greater detail. Copies of the above correspondence are included in Appendix A.
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II. DESCRIPTION OF RESTRAINI DESIGI Typically, the pipe whip restraints designed for- the SNUPPS project are combinations of the three' basic types of restraints shown in Figures 1 through 3. Since the piping system is designed to preclude rupture, even under various upset conditions, including a seismic event, the restraints serve no identified function in normal plant operation.
They are provided as an additional safety feature to mitigate the consequences of a postulated pipe break. To prevent interference with normal operation of the piping and its support systen, the restraints are separated. from the pipe by an air gap. The postulated pipe failure must overcome the gap before impact with the restraint occurs. .
Each of the restraint types has four common elements: 1) An energy-absorbing device to absorb the kinetic energy of the moving pipe and transform the impactive dynamic load of the- pipe moving through a specified gap into an impulsive dynamic load. This device consists either of a stainless steel honeycomb energy absorbing material (EAM) l or specially designed upset rods (U-bolts). 2) A steel restraint l
l substructure which delivers the dynamic loads to 3) the primary structure I
(a concrete wall or slab or in some instances structural steel) and 4) an anchorage system which provides for load transfer from the steel restraint subs tructure to the concrete wall or slab. This anchorage system utilizes l
anchor bolts or headed studs which are attached to a plate which provides an attachment surface for the substructure.
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Stainless Steel Upset Rod (U-Bolts)
H *~~ " 3 -*--Support Steel (Subs tructure)
When Fj Is Applied Away From the Support Embedded or Surface-Mounted Plate Steel, U-Bolts Are /
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l NOTE: For discussion purposes, restraint guides in the directions other than Fj direction are not shown here.
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The design of these supports was performed in accordance with a Design Guide prepared by project personnel specifict Lly for the SNUPPS Project. The major requirements of the guide are sun =eized as follows:
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- 1. The energy balance method described in BN-TOP-2 is used to account for dynamic impact effects. BN-TOP-2 has been approved by the NRC for this application. (The energy balance method is not required to be used however, in those cases where the development of the plastic moment of the pipe can not be prevented. See item 6 below.)
- 2. To account for the impactive dynamic loads created by the air gap between the pipe and the restraint, either a crushable energy absorb-ing material or stainless steel U-bolts may be used.
- 3. To simplify the design, *.he energy absorbed by the ruptured pipe 1
may conservatively be neglected.
- 4. The static equivalent force used for design of the restraint steel substructure and embeds shall be the upper bound strength of the U-bolt or ten percent higher than the nominal crushing strength of the energy absorbing material.
- 5. The restraint steel substructures and embed was designed using i
elastic design methods during impact when either the crushable type energy absorbing material or the elongating type U-bolts are used.
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- 6. When a plastic hinge is developed ht the ruptured pipe at tre restraint location, a static equivalent force equal to 1.2 times -
the jet thrust force (Fj) or 1.2 times the plastic moment of the -
pipe divided by the cantilever distance from the restraint to the thrust force (F5/L) whichever is larger, is used for design of the restraint.
Items 4, 5, and 6 above were found to be unconservative since they did not .
T consider the dynamic nature of the loading. However, this Design Guide includes several conservatisms which, although not evaluated , tend to mitigste the cons-quences of the design discrepancies identified in this report. They include the following :
A. The rise time of the jet thrust force was $onsidered to be instan-taneous and its magnitude considered to be constant at the peak value. (Triple step function loadings, which could make this assumption unconservative, do not occur on SNUPPS.)
B. The energy dissipated by the work done on the pipe during rupture was not considered .
C. The energy absorbed by the pipe due to deformation of the pipe itself was not considered .
D. The reduction in energy transfer due to the conservation of
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I III. DESCRIPTION OF THE DESIGi DISCREPANCIES In order to develep a practical restraint system and minimize the number of req-uired restraints, it is necessary to resist the impact load on the straight port-ion of the pipe, generally just beyond the elbow. In restraint designs where relatively small diameter pipes are involved (usually 4 inch diameter arid under) and high operating pressures are encountered,-it is not feasible to place the restraint suf ficiently close to the elbow of the pipe to prevent the pipe collapse moment from being developed. khen this situation occured, the project design criteria required that an upper bound load be transmitted to the restraint (see item 6,Section II) which exceeded the static force which could be imposed on the re s t raint. s. The project criteria contained in the SNUPPS Design Gui,de did not require that an energy balance analysis be performed in accordance with BN-IOP-2 in addition to the established maximum force level. Although energy absorbing devices were employed on all restraints and the resisting force level identified, the required deformation necessary to absorb all developed energy in accordance with BN-TOP-2 for this class of restraints was not considt red. The restraints were designed to a force level that exceeded the static capt oility of the pipe; however, this consideration did not account for the dynamic nature of the pipe action.
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As indicated in item 4 of Section II, the project design criteria also required that the restraint structure be designed f or an upper-bound energy absorption device load. In certain cases the restraint - substructure was designed to resist the theoretical " crush" load of the energy absorbing device but the cross-sectional area of the EAM or the diameter of the U-bolts was up-sized for reascus of conven-ionce and simplicity. Although this upsizing resulted in increased capacity of the energy absorbing device, it created a reduction in the intended design margin of the restraint structure as ccmpared to the energy absorbing device resulting in a violation of the project design criteria described in item 4 in Section II.
The load applied to the energy absorbing device is of an impactive dynamic nature f ran the postulated pipe break. The energy absorbing device absorbs the energy developed by the accelerating pipe, resulting in a substantially reduced force level imposed on the restraint substructure. However, the restraint structure remains subject to an impulsive type response due to the sudden appli-cation of the load through the EAM or U-bolt. To account f or this ef fect, all l
restraints previously designed on an elastic basis and issued for construction i
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are being reviewed. Consistent with the design criteria and load combinations identified in the SAR and approved by the NRC, elastic plastic behavior of the restraint structure is permitted.
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IV. ANALYSIS OF SAFETY IMPLICATIONS Pipe whip restraints are provided where, as a result of a postulate 41 high energy pipe break, following a single break, the unrestrained pipe movement of either end of the ruptured pipe can not be allowed to damage, to an unacceptable level, any structure, system, or component required to place the plant in a safe shutdown condition or mitigate the consequences of the rupture. Pipe failure protection is required in 10 CFR 50, Appendix A, GDC 4.
It has not been determined whether the discrepancies identified in this report would have, in fact, affected the performance of the pipe whip .
restraints to the extent where they would allow unacceptable damage to any structure, systen, or component required to place the plant in a safe shut down condition. As indicated previously, several unquantified conservatisms exist, which if evaluated, may show that the restraints are -
adequate. However, 'such an analysis has not been performed. Instead, the designs ha te or will be modified as required to conform to the requirements of Bechtel's BN-TOP-2 and to consider the dynamic nature of the load in the design of the steel restraint substructures.
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-9 V. METHOD OF RESOLUTION A review of the design indicated that, 103 of a total of 242 restraints issued for construction prior to the identification of the design dis-crepancies were affected either by the absence of energy balance techniques in the design of the restraints or by the upsizing of the energy absorbing de-vices. All of the 103 restraints in question were reviewed and reanalyzed using energy balance techniques consistent with BN-TOP-2 and/or a rigorous dynamic analysis using a lumped-sass dynamic model . As a result of the design review, 44 restraints were revised. A description of these restraints, inclu' ding the revisions =ade, is given in IABLE I.
The restraint substructures which may be adversely affected by the dy'namic
- nature of the suddenly - applied load created by the energy absorbing devices are listed in Table II. Each of these substructures will be rean-alyzed using standard elastic perfectly plastic techniques. This rean-alysis will assure that the restraint behaves in a ductile manner with sufficient strength to resist the postulated sudden application of the upper bound energy absorbing device load and remain within acceptable duct-ility limits. These limits are identified in Bechtel Topical Report BC-TOP-9 A, l
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l as approved by the NRC. Practices standard to the American Institute of Steel Construction for plastic design and analytical techniques identified in Biggs (1) will be employed. Resistance functions of the structures will be based on minim 2m specified yield strength. Restraints which are not ad-versely affected by the dynamic nature of the load include those restraints which act merely as pipe guides and those restraints which are under compres-sion, providing instability is not a concern. No reanalysis is required for these restraint substructures.
A preliminary review of the restraints listad in Table II indicates that, in general, the restraint substructures as designed, exhibit ductile charac-teristics and have sufficient margins to remain within allowable ductility limits. 'The possibility exists that, in some cases, modifications may have to be made to the substruebres. These modifications may include adding stiffeners or bracing, altering section properties by trimning material, adding weld material, etc. These modifications may be accomplished on the completed structures. Specific details of these revisions will be determined by. detailed engineering analysis. A sumary report identifying the modifica-tions made, if any, as a result of the reanalysis, will be generated following completion of the reanalysis and revisions.
F (1) Biggs, J. M. , Introduction to Structural Dynamics, McGraw-Hill Beck Company, 1964
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- VI. CONCLUSIOSS The design of the pipe whip restraints for the SNUPPS Project contained elements which were not consistent with the requirements of BN-TOP-2.
Additionally, the dynamic nature of the loading was not fully considered in the design of the steel restraint structures. These supports were or will be reanalyzed and revised, as necessary.
Vll. CORRECTIVE ACTION The corrective action taken involves a combination of re-analysis and revis-ion, where necessary, of all af fected restraints and revision of the FSAR and the Design Guide. In addition, information concerning these discrepancies is being furnished to other projects within the Gaithersburg Power Division and to the other Bechtel Power Corporation Divisions for review. Should it be det-ermined that these oiscrepancies occur on other Bechtel projects, this will be re-ported by the cognizant Bechtel Division directly to the cognizant Director of the NRC Regional Of fice of Inspection and Enforcement. In such instances the affected Licensees will be so notified.
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. 4 Both the FSAR and the Design Guide for. the SNUPPS Project are being revised to require the use of energy balance methods or other dynamic methods in .
those cases when the collapse :aoment of the pipe is formed. Also, these documents are being revised to require that the restraint system itself be analyzed for the impulse load from the energy absorbing device. Speci-fically, the restraint will be designed either using an appropriate dynamic load factor if they are to remain elastic, or alternatively, to remain within allowable ductility ratios if an elasto-plastic analysis is performed.
Reanalysis and revisions, as necessary, will be completed by September 1,1981.
The Design Guide will be revised and reissued by June 15, 1981. Ihe FSAR changes will be incorporated in Revision 5 of the FSAR. A repcre identifying those restraints listed in Table II which require modification, will be gena-rated by October 1,1981.
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Page 1 of 3 TABLE I Restraint Pipe Diameter and Number System Description Description of Revision EP1-1 10" d Accunnlator Revised U-Bolt Size and Iangth; Safety Injection Line Adjusted Restraint Steel Dimensions l
EP2-1 Same as Above Same as Above EP2-5 Same as Above Revised EAM Size and Adjusted Restraint Steel Dimensions EPl-5 Same as Above Revised EAM Size and One Steel Member BG21-3 3" d BG (CVCS) Class II Revised U-Bolt Size and Revised Steel Members BG21-12 Same as Above Revised EAM and Steel Member Sizes ,
BG21-5 Same as Above Same as Above BG21-6 Same as Above Same as Above BG21-10 Same as Above Same as Above BG23-1 Sare as Above Revised Steel Mc.%er Size BG23-4 Sam as Above Revised EAM and Steel Member Sizes BB-8 6" si Pressurizer Spray Revised EAM Size and Adjusted Re-Line. straint Steel Dimension BB-9 Same as Above Same as Above BB-10 Same as Above Same as Above BB-11 4" d Pressurizer Spray Revised EAM Size and Adjusted Re-Line straint Steel Dimension BB-15 Same as Above Same as Above BB-14 Same as Above Same as Above BB-16 Same as Above Same as Above e
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Pege 2 cf 3 TABLE I Res traint Pipe Disneter and v Number System Description Description of Revision BG24-15 2" d BG (CV"') Class I Revised U Bolt Size and Steel Attachment BG24-10 Same as Above Revised EAM Size and Steel Member ,
EJ-2 12" 6 Residual Heat Revised EAM Size and Adjusted Re-Removal straint Steel Dimension BG22-1 3" d BG (CVCS) Class I Revised U-Bolt and Steel Sizes BG22-4 Same as Above Revised EAM and Steel Sizes BB-20 1-1/2" d High Pressure Revised U-Bolt and Steel Sizes Coolant Injection BB-21 Same as Above Same as Above
- BB-23 Same as Above Same as Above ,
BB-24 Same.as Above Same as Above BB-29 Same as Above Revised EAM and Steel Sizes BB-31 Same as Above Revised U-Bolt and Steel Sizes BB-33 Same as Above Revised EAM and Adjusted Steel Dimen.
BB-34 6" 6 HPCI Revised EAM and Steel Sizes BB-36 Same as Above Revised U-Bolt and Steel Sizes BG21-16 3" d BG (CVCR) Class I Revised EAM Size sai Adjusted Steel Dimensions BG21-17 Same as Abeve Same as Above BG21-19 Same as Above Revised EAM Size BG21-22 Same as Above Revised U-Bolt and Steel Sizes BG21-23 Same as Above Same as Above
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Restraint Pipe Diameter and Number System Description Description of Revision BB4-7 14" 6 Surge Line Revised FAM Size and Added a Steel Column FWR 10 & 10A 14" 6 Feedwater Revised U-Bolt and Steel Sizes FWR 1 & 1A Same as Above Revised Iangth of U-Bole F*n'R 2 & 2A Same as Above Same as Above i
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l Drawing No. Drawing No. I No. Restraint No. C-03XXXX (Q) No. Restraint No. C-03XXXX(Q) 1 BB4-1 BB51 31 BG22-2 BB58 2 BB4-2 BB51 32 BG22-4 BB58 3 BB4-3 BBS1 33 BB20 BB59 4 BB4-4 BB50 34 BB21 BB59 5 BB4-5 BB50 35 BB23 BB59 6 BB4-6 BB50 36 BB24 BB59 7 BB4-7 BB50 37 BB26 BB60 8 BB4-8 BB50 38 BB27 BB60 9 BB4-9 BB31 39 BB28 BB60 10 BB-1 BB54 40 BB29 BB60 11 BB-2 BB54 41 BB30 BB61 12 BB-3 BB54 42 BB31 BB61 .
13 BB-4 BB54 43 BB33 BB61 -
14 BB-5s 44 BB34 BB62 15 BB-6q BB5" 45 BB35 BB62 16 BB 17 BB-8 ,
18 BB 47 BG21 BB55 BB63 19 BB-10 48 BG21-17j 20 BB24-15 49 BG21-19 BB63 21 BB-11 BBS5 50 BG21-20 BB63 22 BB-14 BB56 51 BG21-21 BB63 23 BB-15 BBS5 52 BG21-22l BB64 24 BB-16 BB56 53 BG21-23 s 25 BG24-10 BB56 54 BG21-2 BG50 26 BG24-13 BB56 55 BG21-3 BG50 27 EJ-1 BB57 56 BG21-5 BGS1 l
57 BG21-6 BG51 28 EJ-4 BB57 29 EJ-5 BB57 58 BG21-11 BG51 30 BG22-1 BB58, 59 BG21-12 BG50
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Descripti~on Description Drawing No. Drawing No.
No. Restraint No. C-03XXXX (Q) No. Restraint No. C-03XXXX (Q) 60 BG21-14 BG51 88 FWR-1 AE51 61 ' BG21-15 BGS1 89 FWR-1A AE51 62 BG23-1 BG52 90 FWR-3 AE51 63 3G23-2 BG52 91 FWR-3A AE51 64 BG23-4 BG52 92 MSR-1 AE51 65 BG23-5 BG52 93 FWR-2 AE51 66 BG23-6 BG52 94 MSR-2 AE51 67 BG24-6 BG53 95 MSR-2A AE51 68 BG24-1 BG53 96 MSR-1A AE51 69 BG24-2 BG53 97 FWR-2A AE51 70 BG24-3 BG53 98 MSR-3 AES2
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71 BG24-4 BG53 - 99 MSR-3A AE52 72 BG24-5 BG53 100 MSR-4 AES2 ,
73 BG24-9 BG53 101 MSR-4A AES2 74 EPl-1 EP50 102 FWR-4 AES2 75 EP2-1 EP50 103 FWR-4A AES2 76 EPl-2 EP50 104 MSR-5 AE52 77 EP2-2 EP50 105 MSR-5A AES2 78 EP1-3 EP51 106 M -5 AES2 EP2-3 i 79 EPS1
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80 EP2-5 EPS1
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82 EP2-8 EPS1
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83 EP1-5 EPS2
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84 EPl-6 EPS2
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85 EPl-8 EPS2
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86 Main Steam AB50 East Tower ABS 1 114 BG-1 BG01 87 Main Steam AB52 115 BG-2 BG01 West Tower AB54 116 BC-3 BG01
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Pcge 3 cf 3 TAB 1Z II Description Description Drawing No. Drawing No.
No. Restraint No. C-03XXXX (Q) No. Restraint No. C-03XXXX (Q) 117 BG-6 BG01 118 BG-7 BG01 119 BG-8 BG02 120 BG-9 BG02 121 BG-10 BG02 122 BG-11 BG02 _
123 FB-1 FB01 124 FB-2 FB01 125 FB-3 FB01 126 FB-4 F301 e
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APPENDIX A Corresponde nce
- 1. SLNRC 81-003, January 23, 1981 .
- 2. SLNRC 81-014, March 16, 1981. >
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SNUPPS .
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- *** 0 SLNRC 81-003 SUBJ: Pipe whip Restraint Design .
Discrepancies .q i
J Mr. Boyce Grier Director, Region I Office of Inspection and Enforcement U.S. Nuclear Regulatory Commission ,
631 Park Avenue King of Prussia, Pennsylvania 19406 Ref: STN 50-482 .
STN 50-483 STN 50-486
Dear Mr. Grier:
On December 24, 1980, NRC Region I (Mr. J. Mattia) was informed by the SNUPPS OA Manager (Seiken) of a potential generic deficiency in the ~
analytical techniques used by the Bechtel Power Corporation iri design of
( pipe whip restraints used for the SNUPPS standard power block.
The problem reported to Mr. Mattia involves nonconservative techniques used by Bechtel in addressing the dynamic impa:t effects on the restraints.
As a result, the possibility exists that the energy absorbing devices (Energy Absorbing Material and upset rods) do not adequately account for the postulated impact of the pipe under all conditions. The restraints involved are mostly those for pipe di reter Size 4 inches or less.
Other conservatisms normally used in the analysis may possibly offset some portion of this problem; however, these conservatisms are difficult j to quantify. As a result, it was concluded that the problem would be
' treated and reported to the NRC as a potential generic deficiency under 10CFR50.55(e) criteria. We are advised by Bechtel that this problem is unioue to the SNUPPS units only.
I In the Dec. 24th telecon report, it was indicated that Bechtel was proceeding to review earl,ier design calculations to determine speci-l fic restraints which are effected by this problem. A final report indicating the scope and extent of the problem and a plan of remedial and corrective actions were anticipated within the normal 30 day re-porting period. Although these actions are well advanced, they will
[
not be completed for another several weeks. Consesquently, a final report will not be issued until Feb. 28, 1981. Mr. Carlson, Region I, NRC, was informed on Jan. 20th of this revised schedule for issuance
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SLNRC 81-003
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of the final report and suggested a summary be provided to the NRC for i use as an interim report. We trust the summary described
- herein will l
prove sufficient in this regard.
Very rul yours,
- 5. J. eiken QA Manager SJS:dek:5a26 cc: Mr. J. A. Keppler, Director, Region III USNRC Mr. W. Wescott, Regica III. USNRC Mr. Karl Seyfrit, Director, Region IV, USNRC -
Mr. Victor Stello, Jr., Director, Office of Inspection and Enforcement, USNRC, Washington, D.C.
T. Vandel, Wolf Creek Resident Inspector, USNRC W. Hansen, Callaway Resident Inspector, USNRC
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