ML19331C131
| ML19331C131 | |
| Person / Time | |
|---|---|
| Site: | Indian Point, Zion  |
| Issue date: | 07/31/1980 |
| From: | Meyer J Office of Nuclear Reactor Regulation |
| To: | Office of Nuclear Reactor Regulation |
| Shared Package | |
| ML19331C132 | List: |
| References | |
| NUDOCS 8008140198 | |
| Download: ML19331C131 (7) | |
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fYA UNITED STATES a ng%
E NUCLEAR REGULATORY COMMisslON j
WASHINGTON D. C. 20555 f.
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Jul. 31 1980 THIS DOCUMENT CONTAINS Docket Nos.: 50-247 5$2!!
P00R QUAUTY PAGES 50-304 LICENSEES:
Consolidated Edison Company of New York Power Authority of the State of New York Commonwealth Edison Company FACILITIES:
Indian Point, Units 2 & 3 Zion, Units 1 & 2
SUBJECT:
SUMMARY
OF TECHNOLOGY-EXCHANGE MEETING 5 HELD ON JUNE 17, 1980 WITH CONSOLIDATED EDISON COMPANY OF NEW YORK (CON. ED), POWER AUTHORITY OF THE STATE OF NEW YORK (PASNY), AND COMMONWEALTH EDISON COMPANY (CECO) TO DISCUSS CONTAINMENT STRUCTURAL RESPONSE FOR INDIAN POINT UNITS 2 AND 3 AND ZION UNITS 1 & 2 A one-day meeting was held in Bethesda, Maryland to discuss containment structural response to core melt accident sequences for the Zion and Indian Point (Z/IP) nuclear power plants. This was the final technology-exchange meeting of five planned as part of the Z/IP action, described in the letter from Schwencer (NRC) to Peoples (Ceco), dated April 10, 1980.
With some minor changes, the announced agenda, Enclosure I, was followed throughout the meeting. An attendance list is included as Enclosure II; Enclosure III is a complete set of meeting viewgraphs.
l Meeting Highlights l
J. F. Meyer opened the meeting by noting the key items of interest for Meeting #5, namely : Z/IP containment failure pressures, locations, and modes; containment loading characteristics; and vessel failure characteristics. He stated that the results of the containment analyses will be used, in part, as input to (CRAC-Code) consequence analysis specific to the Z/IP plants. The major portion of the agenda was dedicated to utility-contractor and NRC-contractor presentations on the Z/IP containment analyses (Sargent & Lundy for Zion; United Engineers &
Contractors for Indian Point; Los Alamos Scientific Laboratory for Zion; and Sandia National Laboratory for Indian Point, respectively). A sumary of the Z/IP con-tainment structural analyses is given in Table I.
Several key points should be made:
All the analyses showed failure pressures considerably higher than that initially assumed (e.g., higher than the range assumed in the " Advanced Draft Copy" version of " Report of the Zion / Indian Point Study: Volume I,"
Sandia, NUREG/CR-1410, namely, a failure range of 75+105 psig for Indian Point) 8008349\\CQ u
JUL 311980 For a given plant the analyzed failure pressures were comparable (within 15%).
Although the failure pressures were comparable, the assessment of failure locations and modes of failure were quite different and thereby disturbing.
(For example, what were the cylinder hoop tendon stresses in the NRC analysis for Zion when the liner was calculated to separate at 154 psig?)
There was general concensus that penetrations are not the containment weak points.
There was general concensus that the failure modes could be characterized as " ductile" as opposed to " catastrophic."
The utility-contractors would not speculate in any detail on the characteristics of the containment failure once the failure was initiated.
G. Klopp (CECO) referred to this portion of the accident sequence as a " grey area" in need of further attention.
All the utility analyses were under the assumption of a static or quasistatic pressure loading of the containment. Although the NRC staff considers that assumption appropriate in most cases, the staff believes that dynamic loading of the containment cannot be rulet out due to either hydrogen explosions resulting from pocketing of hydrogen gas or rapid (near sonic) burning of hydrogen.
There was concensus that temperature loading of the containment was not a problem, in the sense of having an effect on the containment failure characteristics.
The details of the four presentations on containment structural analyses can be found in the Enclosure III viewgraphs. One area that was not addressed was the capability of these containments to withstand a partial vacuum. This is of concern for determining functional requirements and criteria for Filtered-Vented Containment Systems and should be addressed in the continuiag NRC programs.
A major uncertainty that was highlighted during technology-exchange meetings
- 1 and 2 was how the Z/IP vessels will fail under given mechanical and/or thennal loadings.
In part "d" of the NRC presentations, R. Alcouffe and C. Anderson of LASL addressed this question in part by reporting on the LASL l
analysis of the vessel response to in-vessel steam explosions, an analysis first i
reported in Vol. II of the previously referenced Z/IP study. Their viewgraphs l
are on pages 113-125 of Enclosure III. Three different work-energy source terms were assumed in order to generate pressure loading histories (head impact pressures) for the vessel structural response analysis.
Configuration "b", characterized j
by large Taylor instabilities, was felt to be most representative. The source tenns were consistent with the steam-explosion estimates developed at LASL and SANDIA. The analyses reported indicate that:
missile generation is unlikely based on " SIMMER" loading histories missile generation is more likely if based on "50LA-V0F" loading histories 1
. JUL 311980 if the head fails, the probability of missile generation is low from the loadings considered, lower portions of the vessel may fail before upper (head) portions.
Mr. S. P. Chan (NRC/SEB) reported on very preliminary results from the "Other NRC Containment Analyses" presently in place for ice-condenser steel containments.
Another topic related to vessel failure modes was brought up, namely, the capability to prevent failure of the vessel by flooding the reactor cavity. Mr. Von Riesemann (Sandia) referred to a report which considered this question some years ago.
This matter should be reconsidered by NRC.
Following the formal presentations there was a general discussion of the Z/IP action program over the next 6 months, a program which will culminate in a decision for or against mitigation feature requirements by NRC in late fall.
/
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'il tre d (D j
James F. Meyer Reactor Systems Branch Division of Systems Integration
Enclosures:
Office of Nuclear Reactor Regulation As stated W
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Gnclosure.- 1 A3EliDA FOR TECHiiOLO3Y-EXCH/: RE f!EETING #5
" CONTAINMENT STRUCTURAL PESPONSE" JL"E 17,1980 8:30AM I.
Introductory Comments -
I'RC Utilities 9:00AM II.
Utility Pe nentations a.
Zion 1.
Containment Description 2.
Bases for Analyses 3.
Method of Analyses 4.
Failure Criteria l
5.
Results 1
10:00AM i.
Indian Point 1.
Containment Description 2.
Bases for Analyses 1.
Method of Analyses 4.
Failure Criteria l
S.
Results 11:00AM Break 11:15AM III.
NRC Presentations a.
Zion Containment Building Evaluation 11:45AM b.
Indian Point Containment Building Evaluation 12:15PM c.
Other NRC Containment Analyses 12:45PM d.
Vessel Failure Analyses l
1:00PM Lunch 2:00PM Review of Meetings, sumaries, discussion 3:30PM Adjourn A
2:iCLOSURE II Attendance List Mel Silberberg inC-RSR llancy B. Willouby Bechtel Jim !! eyer NRC/NRR John Olshinski NRC/:iRR John Long
- 1RC?NRR R. Philip Hamond.
R & D Associates Er-Ping Chen SMIDIA Walter A. Vcn Riesemann SANDIA James Leas UCS Bill Bennett Con Edison W. Sayed Power Authority of State of U.Y.
James F. Davis Power Authortiy of State of N.Y.
N. F. Conrad NRR D. L. Peoples Commonwealth Edison Hatum Radwan Sargent & Lundy Bryan Erler Sargent & Lundy Joe Uccifierro UE & C David C. Jeng NRC/NRR/SEB D. E. Bessette NRC/ACRS Jan S. Teraszkiewicz Power Authority of State of N.Y.
G. T. Klopp Commonwealth Edison F. Schauer NRC P. T. Kuo NRC Charles A. Anderson LASL Goutam Bagchi NRC/RES Richard Perry United Engineers & Const. Phila.
Y. W. Chang MIL R. U. Seidensticker MIL J. B. Van Erp KIL Victor Gonnella Con Edison Raymond Alcouffe LASL Peter Cybulskis Battelle Columbus Charles Tinkler 3RC D. H. Cho ANL l
U. A. Wogsland Commonwealth Edison Profull Kakkad Bechtel Power Corp.
I Reimar Duerr United Engineers & Const. Phila.
R. U. Barton United Engineers & Const. Phila.
B. N. Washbtyrn
- DOE, Richard Toland United Engineers Joel Bennett Los Alamos Elton Endebrock LASL Gary Quittschrei6ar NRC/ACRS Gary Boyd SKIDIA J. C. LaVallee Sargent & Lundy Martin Oper Westinghouse Don Paddleford W
E. E. Schmidt NUS Gary ::. Rush Ph11ahl-hia Electric Co.
R. ~:. Henry Fausk3 & Assoc. Inc.
D. C. Bley Westinghouse Elec. Corp
d Robert E. Kelly 1.'estinghouse Elec. Corp garry R. Thomas
!! SAC Rick Sherry
- iRC/RES Ray DiSalvo
!!RC/RES L. S. Rubenstein IIRC M. C. Leverett liSAC (EPRI)
R. D. Gasser Brookhaven :Tatl. Lab.
P. II. Uilliams iRC/ iRR/ DST /RSC3 T. J. Ualker liRC/CS/AESR R. S. Orr U Offshore power Systems Charles I;elber
- iRC W. H. Layman USAC/IPRI R. P. Remshaw Con Edison Martin J. Scott Con Edison Jay D. Dunkleberger
- 1YS Energy Office John Yerick DOE Taft Broone IIRC/RES Joanne Dann Mcgraw-Hill Calin A. Laldwell B&U R. J. Face LACO John S. Ma SEB/:iRC Shankar Meon Studsvik, Sweden M. S. Medeiros, Jr.
iRC/SD Robert Sugarman IEEE Spectrum Magazine Leonard Olshan URC/0RB-1 Ed. Reeves URC/0RB-1 Michael W. Dobbe XiCO Engineers, Inc.
Ed. Fensternacher URC/:iRR/RSB J. L. Carter NRC/RSB Fritz Sturz EPS/GRP i
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4 TABLE 1 -
SUMMARY
OF Z/IP CONTAINMENT STRUCTURAL ANALYSES j
N Analysis of FAILURE-PRESSURE /
FAILURE FAILURE MODE CONTAINMENT DESIGN-PRESSURE,PSIG LOCATION
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LOADING CHARACTERISTICS REACTOR +
ZION 134/47 1/2 way Hoop Tendon Quasistatic (UTILITY ANAL)
(with liner) up cylinder yielding ZION near spring Liner Separates Quasistatic (NRC ANAL.)
154/47 line on cylinder (concrete already (also analyzed dynamic gaggg pgj loadings) non-INDIAN PT.
high on cylinder Hoop, ductile (UTILITY ANAL) 126/47 away from discontinuities Quasistatic INDIAN PT.
just below spring Bending Failure, (NRC ANAL.)
110/47 line or at cyl. basemat ductile Quasistatic intersection (also analyzed dynam,ic loadings)
REFERENCE Top of Cracking of WASH-1400 85/39 Containment concrete followed Quasistatic PWR by liner failure; rapid depressurization O
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.n ENCLOSURE III VIEWGRAPHS FROM JUNE 17, 1980 TECIUiOLOGY EXCIANGE MEETIMG #5 "CONTAII.HENT STRUCTURAL RESPONSE" 1
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