ML20043F183
| ML20043F183 | |
| Person / Time | |
|---|---|
| Site: | 05000605 |
| Issue date: | 06/08/1990 |
| From: | Scaletti D Office of Nuclear Reactor Regulation |
| To: | Office of Nuclear Reactor Regulation |
| References | |
| NUDOCS 9006140231 | |
| Download: ML20043F183 (10) | |
Text
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June 8, 1990 Docket No. STN 50-605 FACILITY:
Advanced Boiling Water Reactor (ABWR) 4 APPLICANT:-
General Electric Company f
SUBJECT:
SUMMARY
OF MEETING WITH GENERAL ELECTRIC ON ABWR 4
On May 16-17, 1990, meetings were held with General Electric j
Company (GE) in San Jose, California.
The purpose of these meetings was to make sure that the remaining major issues in the
)
ABWR design review were receiving appropriate attention by the j
staff and GE.
The discussion topics are identified below:
ABWR SEVERE ACCIDENT RESPONSE:
i I
1.-
Drywell head failure
- Seal leakage
- Structural failure i
2.-
Containment overpressure protection
- Thermal hydraulic response of pool (flashing)
- Need for demister
- Manual operation (bypass of rupture disks)
- Sequence specific timing to disk rupture
'3.
Source Term
- Delayed fission product release
- Source term into containment, credit for non-cafety j
systems
- Concern over ability to meet 25 rem at one-half mile 4.
Shutdown Risk
- GE's view on shutdown risk - why not considered in ABWR PRA l
S.
Other PRA topics as appropriate
^
i 1.
Drywell Head Failure:
a)
Drywell Seal Leakage - The staff was concerned about the
]
GE analyses.which assumed that significant seal leakage would occur at 52 psig (design pressure 45 psig).
GE stated that'the assumed leakage was based on a bounding analysis.
- However, realistically they would not expect any leakage at 52 psig.
GE will get back to us on this issue and the issue of the proposed use of Silicone Rubber Seals.
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b) Structural Failure - GE's analyses assumed drywell head 1
failure at 90 psig; the calculated failure pressure-was 100 psig.
The staff sees this as a significant problem in view of the previous findings that most of the similarly designed (i.e., 45 psig design pressure) BWR containments can withstand higher ultimate pressures.
GE agreed to increase-the drywell head pressure capability.
This would not be a major modification and would probably result in an ultimate containment failure pressure-in excess of' 120-130 psig.
2.
Containment Overpressure Protection:
a)
It appears that GE has done sufficient analysis to conclude that 1) pool swell and rapid depressurization are not a problem, GE has determined that depressurization will take approximately one-half hour; 2) a demister is not necessary; and c) the period prior to the vent actuation can be extended (probably beyond 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />) through optimized use of the Fire Water System.
GE also agreed not to use Limestone concrete in the.drywell cavity area in order to reduce the generation of non-condensable gasses; thereby minimizing early challenge to containment and the overpressure protection system, b)
Manual operation of containment overpressure device:
GE has agreed to reconsider the need for manual control (provision of a bypass valve around a rupture disk) over the vent process.
They will get back to the staff on this issue.
3.
Source Term:
GE agreed to expedite their submittal to justify taking credit for plate-out and holdup of fission products in the non-seismically designed steam lines and condenser and to track the BWR Owners Group on this issue.
However, GE wishes to maintain their existing SSAR analysis concluding compliance with l
Part 100 should the effort to give credit for non-seismic equipment be delayed..
l 4.
Shutdown Risk:
l GE is convinced that the risk during shutdown condition is l
low for BWRs.
They will submit a qualitative discussion supporting their beliefs.
k 5.
Other PRA topics as appropriate:
H-a) Fire and Seismic Risk - GE is following the EPRI lead (no j
PRA needed for Fire but PRA to be done for Seismic Events),
h There appears to be two problems with this approach.
Probabilistic analysis of seismic events to sg/RY to 10 1) ow that th se 9
events are not significant at a frequency of 10
/RY is only going to lead to unnecessary debate in view of the mostly subjective nature of the methodology. (Note, we are talking about i_
earthquakes well in excess of 1G peak ground acceleration).
A margins type approach might be more sensible.
2)The approach for
'N Fire and Seismic Events should be consistent.
The staff plans to meet with EPRI in the near future to discuss this matter.
.- June 8, 1990-
.a b) Lower Drywell Flooder - GE will provide 1)-the. lower drywell flooder design information and the testing _to be conducted, 2) estimated steaming rate when substantial amount of core debris is ejected into a pool of water in the lower drywell, and 3) identification of events when the lower drywell is flooded before the core debris is expected to reach the drywell.
The meetings.were very fruitful in that several potentially tough-issues have been dealt with by GE in a very responsive manner. -is the meeting notice. contains
. preliminary information presented by GE related to a fire water addition study. is a list of meeting attendees.
Isl Dino C.
Scaletti, Project Manager Standardization Project Directorate Division of Reactor Projects - III, IV, V and Special Projects Office of Nuclear Reactor Regulation
Enclosures:
As stated DISTRIEUTIQH3
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-CMiller JCunningham PDS'r/f WTravers FCongel NRC Participants WRussell JPartlow ACRS (10)
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.-same UNITED STATES ENCLOSURE 1' NUCLEAR REGULATORY COMMISSION -
6; WASHINGTON D, C. 30665
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< Docket No. STN 50-605 MEMORANDUM FOR:
T. Murley B. Grimes P. McKee F. Miraglia F. Congel A. Thadani W. Aussell, ADT J. Roe Acting Chief. EAB J. Partlow, ADP C. Grimes J. Dyer, EDO D. Crutchfield, ADSP B. Boger Operations Center S. Varga G. Lainas F. Gillespie G. Holahan M. Virgilio W. Bateman C. Rossi B. D. Liaw-L. Reyes, RII J. Richardson E. Butcher T. Cox J. Zwolinski W. Lanning W. Travers THRU:
Charles L. Miller, Director Standardization Project Directorate Division of Reactor Projects - III, IV, V and Special Projects FROM:
Dino C. Scaletti, Project Manager Standardization Project Directorate Division of Reactor Projects - III, IV, Y and Special Projects
SUBJECT:
DAILY HIGHLIGHT - FORTHCOMING MEETING WITH GENERAL ELECTRIC COMPANY (GE) TO DISCUSS THE STAFF'S REVIEW OF THE ADVANCED BOILING WATER REACTOR. -(SEE ATTACHED LIST OF DISCUSSION
. TOPICS)
DATE & TIME:
May 16-17, 1990 9:00 A.M. - 4:30 P.M.
LOCATION:
General Electric Company 175 Curtner Avenue San Jose, California
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- l Daily Highlight May 16-17, 1990,
s-j PARTICIPANTS *:
NRC GE D hadani T Quirk T. Pratt NRR J. Duncan 1
J. Kudrick, NRR J. Fox G. Bagchi, NRR C. Sawyer M. Rubin, NRR W. Hardin, RES J. Lee, NRR i
D. Scaletti, NRR J' u c.S M C. Scaletti, Project Manager Standardization Project Directorate Division of Reactor Projects - 111, IV, V-and Special Projects l
cc: See next page
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- Meetings between NRC _ technical staff and applicants or licensees are open for interested members'of'the public, petitioners, intervenors, or other parties to attend as observers pursuant to "Open Meeting Statement of NRC Staff Policy," 43 Federal Register 28058,6/28/78.
However portions of this meeting may be closed to the public to protect General Electric Company proprietary information. Mem>ers of the public who wish to attend should contact D. C. Scaletti at (301)'492-1104.
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' Mr. P. W Marriott-
-Docket No. STN 50-605 General. Electric Company cc: Mr. Robert Mitchell General Electric Company 175 Curtner Avenue' San Jose, California 95114 Mr. L. Gifford, Program Manager Regulatory Programs GE Nuclear Energy 12300 Twinbrook Parkway Suite 315 Rockville, Maryland 20852 Director, Criteria & Standards Division Office of Radiation Programs U. S. Environmental Protection Agency l-401 M Street,-S.W.
i Washington, D.C.
20460 Mr. Daniel F. Giessing Division of Nuclear Regulation and Safety Office of Converter Reactor 1
Deployment NE-12 Office of Nuclear Energy Washington, D.C.
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4 AGENDA 3<
STAFF /GE 4
MAY 16-17, 1990 ABWR SEVERE ACCIDENT RESPONSE:
1.
Drywell head failure Seal leakage Structural failure 2.
Containment over pressure protection Thermalhydraulicresponseofpool(flashing)
E Need for demister Manualoperation(bypassofsecondrupturedisk)
Sequence' specific timing to disk rupture 3.
Source Tenn Delayed fission product release Source term into containment, credit for nonsafety i
systems Concern over ability to meet 25. rem at one-half mile l:.
4.
Shutdown Risk l
GE's view on shutdown risk - why is it not considered in ABWR PRA Other PRA topics as appropriate-5.
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ENCLOSURE 2 y
24 HOUR FIRE WATER ADDITION STUDY GOAL:
FA SYSTEM ALONE CAN PREVENT THE ABWR CONTAINMENT FROM EXCEEDING " SERVICE LEVEL C" DURING THE FIRST 24 HOURS OF AN ACCIDENT SCENARIO a
CONTAINMENT PRESSURE < 85 PSIG l
PHYSICS OF THE PROBLEM:
DECAY HEAT HEAT GENERATION ABSORPTION I
I HEAT ABSORPTION HEDIA:
SUPPRESSION POOL WATER ADDED FA WATER STRUCTURAL HEAT SINKS CEB/DBM - 5/16/90 - PAGE 1
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RESULTS OF MAAP RUNS EVENT TIMES (HOURS)
PRESS DW >
CASE FA ON FA 0FF 85 PSIG K/5 4.0 23.8 28.6 K/5 +-30% Mi 4.0 26.1 28.9 K/5 THROTTLE A 4.0 24.7 26.9 K/5 THROTTLE B 4.0 39.0 22.5 TRUCK 4.0 19.7 25.0 TRUCK + 30% Md 4.0 20.0 23.6 TRUCK THROTTLE C 4.0 26.2 30.8
- TRUCK THROT. C + 30% MW 4.0 26.8 29.8 TRUCK THROTTLE D 4.00 23.6 28.4 CEB/DBM - 5/15/90 - PAGE 4
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CONCLUSIONS FA SYSTEM CAN PREVENT THE ABWR CONTAINMENT FROM REACHING " SERVICE LEVEL C" DURING THE FIRST 24 HOURS IF BOTH MINIMUM AND MAXIMUM FLOW LIMITS ARE MET.
l HITACHI K/5 PUMP PROVIDES THE REQUIRED FLOW WITH L
THE CURRENT ABWR DESIGN THE FIRE TRUCK PUMP NEEDS TO BE-THROTTLED SLIGHTLY TO GUARANTEE THAT THE-REQUIREMENT IS MET 1
i
- A9 CEB/DBM - 5/16/90 - PAGE 5
i t-ENCLOSURE 3 ATTENDEES HEQ General Electrig A. Thadani J.
Fox T.
Pratt C. Buchholz M. Rubin E. Nichols B. Hardin P. Billig 1
J.
Lee H. Townsend G. Bagchi C. Sawyer J.
Kudrick J.
Duncan D.
Scaletti R. Mitchell A. Liu H. Careway l
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