ML19290C626
| ML19290C626 | |
| Person / Time | |
|---|---|
| Site: | Indian Point, Zion  |
| Issue date: | 01/10/1980 |
| From: | Zech G Office of Nuclear Reactor Regulation |
| To: | Eisenhut D Office of Nuclear Reactor Regulation |
| References | |
| NUDOCS 8001220197 | |
| Download: ML19290C626 (11) | |
Text
- '
'2f) 4
/q 1
/
f a anos\\
UNITED STATES
+[ D $.<
i NUCLEAR REGULATORY COMMISSION E
- 3 WASHWGTON, D. C. 20555
/
4e JANUAay ' 0 230 Occket Nos. 50-295/304 and 6(-247J286 MEMORANDUM FOR: Darrell G. Eisenhut Acting Director Division of Operating Reactors FROM:
Gary G. Zech, Technical Assistant Division of Operating Reactors
SUBJECT:
SUftARY OF MEETING HELD ON DECEMBER 5, 1979, WITH COMMONWEALTH EDISON COMPANY (CECO ), CONSOLIDATED EDISON COMPANY OF NEW YORK (CONED) AND POWER AUTHORITY OF THE STATE OF NEW YORK (PASNY) REGARDING THE ZION STATION UNITS 1 AND 2 AND THE INDIAN POINT UNITS 2 AND 3 FACILITIES On December 5,1979, we met with representatives of CECO, Coned and PASNY to advise them of a staff review that was being considered on the Zion Station Units 1 and 2 and Indian Point Units 2 and 3 sites. Reference was made to our letters of November 29, 1979, which provided preliminary information regarding this review. Agenda ar.d attendance list are attached.
As a matter of introduction, the staff stated that it recognizes that, in the event of a severe reactor accident, evacuation could present special problems should the accident occur at a facility located near a high population area and that a greater population risk existed in areas of high population density even with improved capability to take protective actions.
In anticipation of such an occurrence, special facility modifications may be appropriate that would be in addition to the general upgrading of the emergency preparedness capabilities of licensee and state and local plans. This upgrading of emergency preparedness is currently in progress for all plants.
The questions that exist, therefore, are what can be done to reduce tne likelihood of a severe reactor accident and what can i)e done to reduce the consequences of such an accident at facilities located in areas of high population densities.
Reference was made to Commissioners' statements that shutdown of these facilities was not a precluded outcome.
The staff indicated that Zion Statica Units 1 and 2 and Indian Point Units 2 and 3 have been selected as two sites for an initial review to determine wnat additional measures and/or design changes might be appropriate in view of the location of these sites in the areas of the highest population densities of all operating plants. Depending on what is learned from the current review, additional sites may be considered for similar reviews in the future.
1785 118 8001229 99 ]
Meeting Sumary JMcMr
.. wu In response to a question from CECO, the staff indicated that additional time to evacuation (delay of releases) on the order of several hours would be an objection of any additional measures that might be considered for implementation. However, it was also noted that the benefits to be gained from any design changes considered, such as a core ladle or filtered, vented containment required quantification following a review of the various accident scenarios hypothesired.
The staff emphasized that the Zion Station and Indian Point reactors are not considered to be any less safe than other plants but in view of their locations, other measures should be considered to compensate for the higher total population risk.
The staff's review, as outlined in the enclosed agenda, will consist of three specific areas, i.e., 1) Improved Interim Operations, 2) Current Performance and Licensing Actions and 3) Accident Mitigation. The first two are intended to provide additional assurance, in the short term, that a severe accident will not occur.
Included among these areas will be resolution and implementation on a priority basis wherever possible, of the staff's positions on generic issues that are outstanding on these facilities. The third area of review will include design changes that have the potential for reducing the consequences of an accident by either delaying a release following an accident to provide additional time for evacuation or by reducing the amount of activity released to the environment.
A followup meeting was tentatively scheduled for December 20, 1979, at which time the licensees were requested to discuss their proposed review of any long tem measures that will be studied and any interim measures that could be taken to further reduce the probability of a severe accident. A parallel review by both licensees and the staff will then be perfomed. Following this review decisions will be made regarding possible future actions.
9, v
Gcry G. e.ech, Technical Assistant Division of Operating Rea:. tors
Enclosures:
1.
Agenda 2.
List of Attendees 1785 119
AGENDA ENCLOSURE 1 o
PURPOSE To discuss possible measures to reduce the orobability of a severe reactor accident and to reduce the consequences of such an accident.
o INTRODUCTION o
BACXGROUND o
SPECIFIC AREAS OF REVIEW Improved Interim Operations TMI-2 Lessons Learned Actions Bulletins and Orders Operator Training / Qualifications Emergency Procedures Human Factors Engineering Considerations Integrated Reliability Evaluation Program (IREP)
Current Performance and Licensing Action License Amendment Applications Generic Issues Unresolved Safety Issues Resident Inspector's Role Operating Experience Accident Mitigation Emergency Preparedness Considerations Degraded Core and Core v lt Accident Scenarios e
Capability of Present Systems Site / Population Data 3.equirements Dose / Risk Evaluations With and Without System Design Changes 1785 120
ENCLOSURE 2 LIST OF ATTENDEES MEETING WITH ZION & INDIAN POINT DECE BER 5,1979 NRC Power Authority State of New York D. Eisenhut P. Sayne G. Zech P. J, Early B. Grimes C. M. Pratt J. Olshinski J. F. Davis A. Schwencer N. P. Mathur T. P. Speis R. L. Goyette J. K. Long G. M. Wilverding P. Collins W. Gmunill Westinchouse L. Olshan L. Soffer R. J. Lutz, Jr.
J. E. Kohler, Region III E. A. Reeves Limerick Ecology Action J. A. Murphy J. C. Glynn L. Fufour C. Kelber M. Silbergerg Illinois Attorney General
- 0. Muller C. VanNiel D. Hansell A. Mann S. Burns New York State Energy Office R. Goddard E. W. McPeek T. DeBoer R. E. Martin J. Craig Sheldon, Harmon & Weiss R. DiSalvo T. Rebelowski E. R. Weiss Connonwealth Edison W. F. Naughton D. L. Peoples G. T. Klopp C. Reed Consolidated Edison W. J. Cahill, Jr.
J. D. O'Toole J. Makepeace W. A. Monti M. L. Lee B. Srandenbury J. P. Davis R. P. Remshaw s
1785 121
MITIGATION OF SEVERE ACCIDENTS
- EXAMINE AND IMPLEMENT FEATURES THAT MAY BE EFFECTIVE IN MITIGATING THE CONSEQUENCES OF MAJOR ACCIDENTS, INCLUDING CORE MELT THE OBJECTIVE IS TO DELAY AND/0R PREVENT CONTAINMENT FAILURE FROM THE CONSEQUENCES OF SEVERE ACCIDENTS; THIS WILL PROVIDE ADDITIONAL TIME FOR IMPLEMENTING EFFECTIVE EMERGENCY PLANS AND ACTIONS AROUND AFFECTED PLANTS; AND IN GENERAL, REDUCE FURTHER THE RESIDUAL RISKS FROM DEGRADED CORE AND CORE MELT ACCIDENTS,
- ACCIDENTS INVOLVING CORE DEGRADATION, INCLUDING CORE MELT
~
l786 122
MITIGATION OF SEVERE ACCIDENTS ACCIDENT CONSIDERATIONS POTENTIAL MITIGATIVE FEATURES / SYSTEMS STUDIES / EVALUATIONS NEEDED IMPLEMENTATION CONSIDERATIONS 1785 123
ACCIDENT CONSIDERATIONS CONSEQUENCES OF DEGRADED CORE AND CORE l'ELT ACCIDENTS TO BE CONSIDERED:
e PARTIAL / EXTENSIVE FUEL MELTING e
HYDROGEN e
CONSEQUENCES OF HYDROGEN BURNING / DETONATION HYDROGEN CONTROL; TO PREVENT AND/0R MITIGATE FOR UNDESIRED e
CONSEQUENCES / EFFECTS e
STEAM EXPLOSIONS e
POTENTIAL FOR STEAM EXPLOSIONS DURING THE EVOLUTION OF A MELTDOWN ACCIDENT e
POTENTIAL MAGNITUDE e
CAPABILITY OF REACTOR VESSEL / REACTOR CONTAINMENT e
" SLOW" CONTAINMENT OVERPRESSURIZATION, I.E., FO! TO MANY HOURS 9
1785 124
ACCIDENT CONSIDERATIONS.
e ACCIDENT SCENARIOS INTERACTION OF CONTAINMENT ENGINEERING FEATURES WITH e
ACCIDENT EVOLUTION, I.E., FAILURE OF SYSTEMS SUCH AS CONTAINMENT COOLERS AND SUBSEQUENT EVOLUTION OF SCENARIO OR POTENTIAL CONSEQUENCES FAILURES (E.G., MECHANICAL) THAT CAN RESULT IN A LOSS OF e
EFFECTIVE CONTAINMENT ISOLATION DISPERSAL OF LARGE AMOUNTS OF RADI0 ACTIVITY IN CONTAINMENT e
RELEASE OF RADI0 ACTIVITY FROM CONTAINMENT (PARTIAL / GROSS e
FAILURE); DURATION OF RELEASE e
ATMOSPHERIC e
GROUND e
1785 12!i
POTENTIAL MITIGATIVE FEATURES / SYSTEMS IMPROVED / DIVERSE CONTAINMENT HEAT REMOVAL e
e CONTROLLED VENT FILTERED CONTAINMENT e
SACRIFICIAL MATERIAL BASEMAT e
A COMBINATION OF THE ABOVE TWO HYDROGEN CONTROL, E.G., BURNING, INERTING, PURGING e
HIGH STACK RELEASE FOR NOBLE GASES PROGRAMMED RELEASE e
1785 126
STUDIES / EVALUATIONS NFFDED CAPABILITY OF INDIAN POINT 2/3 - ZION 1/2 SYSTEMS e
(I.E., PRESSURE VESSEL / PRIMARY BOUNDARY, CONTAINMENT)
TO ACCOMMODATE / DELAY CONSEQUENCES (OR SOME OF THEM) 0F DEGRADED CORE, CORE MELT ACCIDENTS ANALYZE / EVALUATE P-T HISTORY IN THE CONTAINMENT FOR A NUMBER e
OF KEY ACCIDENT SCENARIOS THIS " INTEGRAL" ANALYSIS SHOULD CONSIDER A BASEMAT e
MADE WITH EITHER CONCRETE (ALREADY IN PLACE) OR SACRIFICIAL MATERIAL THIS EVALUATION IS NEEDED FOR THE DESIGN OF A VENTED-FILTERED e
SYSTEM (ASSUMING ONE IS NEEDED), AND THE SIGNALS TO ACTUATE IT.
e RADIOLOGICAL SOURCE TERM ESCAPING CONTAINMENT WITH/WITHOUT FEATURES / SYSTEMS SUCH AS VENTED-FILTERED CONTAINMENT CONSEQUENCE EVALUATIONS (USING THE CRAC MODEL ADOPTED FOR, SPECIFIC PLANT SITES) WITH/WITHOUT FEATURES / SYSTEMS SUCH AS VENTED-FILTERED CONTAINMENT 1786-127
IMPLEMENTATION CONSIDERATIONS EFFECTIVENESS
- OF FEATURES / SYSTEMS IN REDUCING THE RESIDUAL e
RISKS OF DEGRADED CORE, CORE MELT ACCIDENTS CONSIDERATIONS IN IMPLEMENTING EFFECTIVE EMERGENCY PLANS AND e
ACTIONS AROUND SUBJECT PLANTS e
SCHEDULE STATUS OF TECHNOLOGY-(FILTERS)
RELIABILITY -
" NEGATIVE" SYSTEMS INTERACTION ASPECTS -
COST VS RISK REDUCTION -
1785 128