ML17249A969
| ML17249A969 | |
| Person / Time | |
|---|---|
| Site: | Dresden  |
| Issue date: | 11/01/1979 |
| From: | Levin H Office of Nuclear Reactor Regulation |
| To: | Crutchfield D Office of Nuclear Reactor Regulation |
| References | |
| TASK-03-06, TASK-3-6, TASK-RR 79101, NUDOCS 7911290285 | |
| Download: ML17249A969 (7) | |
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UNITEDSTATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D. C. 20555 H
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ggyp $ 879 MEMORANDUM FOR:
Dennis M. Crutchfiel d, Chief Systematic Evaluation Program Branch, DOR FROM:
SUBJECT:
Howard A. Levin Systematic Evaluation Program Branch, DOR
SUMMARY
OF MEETING WITH COMMONWEALTH EDISON COMPANY-DRESDEN 1
AND 2 On October ll, 1979, the NRC staff and staff consultants met with respresent-atives of Commonwealth Edison Company (CECo) to discuss the Systematic Evaluation Program (SEP) seismic review of Dresden Units 1 and 2.
Attendees are listed in Enclosure 1.
The purpose of the meeting was to 1) summarize the Senior Seismic Review Team's (SSRT) seismic review of Dresden 2 and discuss various open issues associated with that review and 2) to discuss the scope and schedule for CECo's seismic evaluation of Dresden Unit l.
The meeting agenda is attached (Enclosure 2).
Dr. William Hall and Dr. John Stevenson, NRC staff consultants and the NRC staff summarized details of the SSRT review and provided a concluding assessment.
This information was previously documented in a draft report mailed to CECo on August 14, 1979.
Various open issues were discussed with emphasis on action CECo was requested by the NRC to take to effect a resolution.
A summary of the open issues is provided in Enclosure 3.
The CECo representatives agreed to verbally contact the staff in two weeks to discuss their action plan. for resolving the remaining open issues.
This would be followed by a CECo submittal to the NRC documenting an action plan which incorporates mutually agreed upon milestones.
The Dresden 1 discussions focused on details of the seismic evaluation program that CECo was requested to initiate in a letter from V. Stello to C. Reed, dated January 15, 1979.
The staff outlined the necessary scope of this evaluation and priorities for completion.
(See Section II of Enclosure 2).
CECo responded that they misinterpreted the January 15, 1979 letter and were not fully aware of the requirement that they initiate a seismic evaluation program of their own.
An understanding was reached as to the scope of the NRC proposed program.
CECo responded that they were in the process of hiring a consultant to assist them in these activities and that they expected to be in a position to start the analytical program by January ll, 1980.
.~] 4 Howard A. Levin Systematic Evaluation Program Branch Division of Operating Reactors
ENCLOSURE 1
LIST OF ATTENDEES DRESDEN 1
AND 2 SEISMIC REVIEW MEETING OCTOBER 11, 1979 NRC H. Levin D. Crutchfield C. Hofmayer P. O'onnor T. Cheng NRC Consultants W. Hall J.
Stevenson CECo R. Janecek N. Smith B. Palagi Sar ent 5 Lund T. Victorine LE L021uk A. Walser NSC R. Koppe KMC R. Schaffstall
ENCLOSURE 2
AGENDA SEP SEISMIC REVIEW DRESDEN 1
AND 2 I.
DRESDEN 2
A.
Summary of SSRT Review B.
Concluding evaluation and assessment C.
Discussion of open issues
.1.
Mechanical a.
RPV supports b.
RPV internal supports c.
CRD hydraulic tubing/supports d.
MOYs on small lines e.
Pipe support spacing (piping designed using Blume curves) f.
Recirculation pump supports 2.
Electrical a.
Battery racks b.
Cable trays and supports c.
Support.of safety related electrical equipment (MCC, Switch gear, control panels, instrument panels, transformers, inverters, etc.)
d.
AC MCC - resonance check DC MCC - location verification e.
Instrumentation and control room panels - verification of similiarity/modifications 3.
Structural a.
Torus Sway Rods 4.
Interaction Problems II.
DRESDEN 1
(General Group 2 Seismic Milestones)
A.
Seismic input available B.
Analysis and evaluation of reactor building and RCPB complete (Report)
C.
Analysis of other Cat.
1 buildings complete (floor spectra, response profiles)
D.
Analysis and evaluation of safe shutdown systems complete (piping, anchorage of mechanical/electrical equipment)
(Report)
E.
Structural Evaluations of (C) above complete (Report)
F.
Analysis and evaluation of ECCS/ES systems complete (piping, anchorage of mechanical/
electrical equipment)
G.
Evaluation of mechanical/electrical equipment complete H.
Licensee submits final reports (with action plan)
I.
NRC review complete J.
Interim NRC Seismic Report/start of integrated assessment WEEK 0
20 24 40 40 48 72 80 88
ENCLOSURE 3 OPEN ISSUES DRESDEN 2 SEISMIC REVIEM The following list documents issues that developed as a result of the Senior Seismic Review Team's seismic review of the Dresden 2 facility.
These issues have been highlighted for a variety of reasons.
- However, in most cases a lack of adequate documentation exists.
Designation here does not necessarily imply a safety deficiency.
However, the NRC staff has determined that further documentation of the seismic resistance capability of these items including an evaluation by CECo is warranted.
It is expected that CECo will develop an action plan for resolution of these open issues including a schedule for completion.
1.
Reactor vessel supports - An evaluation is required that considers buckling of the RPV support skirt.
The dynamic loads as determined through consideration of measured or computed dynamic characteristics of the overall RPV support system should be utilized.
The SSRT has suggested that an integrated/coupled model of the RPY support and internals be considered.
2.
Reactor pressure vessel internals - An evaluation of the core support 'structure is required that considers potential resonance and utilizes appropriately amplified loads.
3.
Control rod drive hydraulic tubing and supports - An evaluation of the CRD tubing is required to determine its integrity considering the flexibility of the overall supporting system.
Consideration is required to assure the pressure retaining capability of the tubing and its hydraulic connections.
4.
Motor operated valves on small lines - An evaluation of the additional torsional and bending piping stress imposed by the response of the eccentric mass of air or motor operators is required to assure that the overall stress in the piping remains below the allowable stress limits.
5.
Pipe support spacing - Verification is required to assure that proper pipe support spacing of piping designed using Blume's curves has been provided.
6.
Recirculation pump supports - The SSRT would like to study the support configuration and assess response characteristics ana overall support integrity.
The
assumptions made in the recirculation loop analyses will be verified.
CECo is requested to supply for SSRT review seismic qualification analyses including design calculations which would permit the above evaluations.
7.
Battery racks - An evaluation is required which either demon-strates the integrity of the existing 125V and 250V battery racks or of the racks in a modified configuration.
Emphasis should be placed on an evaluation of the wood slats.
8.
Cable trays and supports -'n evaluation of the support integrity of station cable trays is required.
The cable pans do not represent a concern.
However, the evaluations should concentrate on understanding response characteristics and demonstrating overall integrity of the support system and providing assurance against significant interaction problems with adjacent equipment.
9.
Support of safety related electrical equipment - An evaluation is required to demonstrate the adequacy of the base and lateral support details of safety related electrical equipment and the anchorage of smaller pieces of electrical equipment mounted on racks or housed in cabinets and internally attached.
10.
a)
AC motor control centers - Additional testing or analysis of the 480V, AC MCCs should be performed to determine that there are no resonance frequencies below 5hz.
b)
DC motor control centers - Additional testing or analysis of the 250V, DC MCCs should be performed to determine that there are no resonance frequencies below 7 hz.
Verification is required to assure that safety related DC MCCs are not located above El 538 feet.
If they are, additional qualification data will be necessary.
Verification of the similarity of the AC and DC MCCs tested with those installed at Dresden 2.
1'1.
Instrumentation and control room panels - Verification that the modifications called for in; General Electric Co., "Seismic Testing of Instrumentation Dresden 2," NID Standards and Qualification Engineering Qualification Proprietary Report Memo 1 (January, 1971),
Rev. l.
were made and that these test results can be said to be applicable to the panels and instrumentation actually installed at the Dresden 2 facility.
1 2.
Torus sway rods - An evaluation of the sway roas and their connection details to ensure that they comprise an overall ductile load-resistant system is required.
1 3.
Interaction problems - A reconnaissance of the plant should be made to ensure that:
a)
Non-category I items will not fall or become dislodged and damage safety related equipment.
b)
Temporary or non-permanent items such as dolleys, gas bottles, block and tackle gear, etc. will not impact safety related equipment.
Provisions should be provided in plant operating procedures to eliminate these potential interaction problems.
I