ML19269G331
| ML19269G331 | |
| Person / Time | |
|---|---|
| Site: | Crane  |
| Issue date: | 12/10/1979 |
| From: | Meyer R Office of Nuclear Reactor Regulation |
| To: | Kulynych G BABCOCK & WILCOX CO. |
| Shared Package | |
| ML19269G332 | List: |
| References | |
| FOIA-80-515, FOIA-80-555, TASK-TF, TASK-TMR NUDOCS 8002010219 | |
| Download: ML19269G331 (5) | |
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Central Files NRR R/F CPB R/F ROMeyer KKniel DEC 101979 G. E. Kulynych Babcock & Wilcox Power Generation Grouc P. O. Box 1260 Lynchburg, Va. 24505
SUBJECT:
TMI-2 CORE DAMAGE ASSESSMENT TASK GRCUP 7.2, AND FUEL EXPERIMENTS AND EXAMINATION TASK GROUP 7.4
Dear Georce:
Enclosed is a draft Introduction for a report that would describe our Core Damage Assessment Group's recomendations. This draft is mv con-tribution as reauested at the f;ovember 19 meeting.
As you knew, many of us also carticipated in the Fuel Exoerirrents and Examination Group's meeting the following day. There is such a large overlac in the charter of these tro groues that I don't think you can introduce the activities of one without discussing the other. Con-secuently, I have preoared an Introduction that acclies to both and that I believe creates the right perscective.
I sugcest that we prepara a joint recort with Sections 7.2 and 7.4 follcwing a comon introduction.
I an sendina this draft to members of both groups with the hope that they will find this to be a useful suggestion.
Sincerely, k
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Ralch 0. Meyer. Leader Peactor Fuels Section Core Perfomance Branch Division of Systems Safety
Enclosure:
As stated BlLiTORY DOCE Hl COM S** ""** "*""
2372 228 orwicch. DSS /CP sua~,ucp.Rotievergav oarc h.12.' /C /79 nacronu n. m.A acooua cu.s. coven ~uc~r pa,~rino cr ice, i,79 239 26, 8M2Mo 1
W G. E. Kulynych cc: Robert Blumberg, ORNL D. L. Burman, Westinghouse Art Carson, EPRI Ed Courtright, Battelle florthwest Dave Hobson, ORfit L. E. Fochreiter, Westinghouse Bill Hookins, Sechtel Bob Leyse, EPRI Andy Millunzi, 00E Michael H. Montgerery, B&W Dillip Satcathy, Bechtel Tony, Statheolos, C-E Gecroe A. Sofer, Exxon James S. Tulenko, B&W E. L. Long, ORNL Neil Todreas, MIT Garry L. Sozzi, GE L. Boman, Westinghouse John E. Hanson, EG3G Dennis E. Owen, EGF, Georce A. Last, Westinghouse Jon Reuschen, Sandia Lab.
Franklin Coffran, fiRC 2372 229 amCE)I SURNAMEk.
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DEC 101979 G. E. Kulynych Babcock & Wilcox Power Generation Grouo P. O. Box 1260 Lyncnburg, Va. 24505
SUBJECT:
TMI-2 CORE DAMAGE ASSESSMENT TASK GROUP 7.2, AND FUEL EXPERIMENTS AND EXAMINATION TASK GROUP 7.4
Dear George:
Enclosed is a draft Introduction for a report that would describe our Core Damage Assessment Group's recommendations. This draft is my con-tribution as requested at the November 19 meeting.
As you know, many of us also participated in the Fuel Experiments and Examination Group's meeting the following day. There is such a large overlap in the charter of these two groups that I don't think you can introduce the activities of one without discussing the other. Con-sequently, I have prepared an Introduction that applies to both and that I belie e creates the right perspective. I suggest that we precare a joint report with Sections 7.2 and 7.4 following a common introduction.
I am sending this draft to members of both groups with the hope that they will find tt 's to be a useful suggestion.
Sincerely, ea
,.2 4/ y,
s' Ra
- 0. Meyer,' Leader Reactor Fuels Section Core Performance Branch Division of Systems Safety
Enclosure:
As stated 2372 230 cc: See next page
G. E. Kulynych cc: Robert Blumberg, ORNL D. L. Burman, Westinghouse Art Carson, EPRI Ed Courtright, Battelle Northwest Dave Hobson, ORNL L. E. Hochreiter, Westinghouse Bill Hopkins, Bechtel Bob Leyse, EPRI Andy Millunzi, DOE Michael H. Montgomery, B&W Dillip Satpathy, Bechtel Tony, Stathoolas, C-E George A. Sofer, Exxon James S. Tulenko, B&W E. L. Long, ORNL Neil Todreas, MIT Garry L. Sozzi, GE L. Boman, Westinghouse John E. Hanson, EG&G Dennis E. Owen, EG&G George A. Last, Westinghouse Jon Reuschen, Sandia Lab.
Franklin Coffman, NRC R. Vollmer, NRC R. Denise, NRC K. Kniel, NRC 2 )~ ' 2 c? 3 l
/
k!. Johnston, NRC M. Picklesimer, NRC J. Voolewede, NRC
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7.0 Reactor Core and Fuel During the course of the Three Mile Island accident and for 30 days prior to achieving natural circulation, the extent of damage to the TMI-2 core and the possibility of aggravating the damage during post-accident maneuvers raised a large number of questions: How much fission product activity could be released? Did the fuel melt?
Did eutectics form? How close to meltdcwn did the core come? How much hy tragen was generated? Was the bubble hydrogen or steam?
Could the bubble explode? Ceuld more hydrogen be generated orior to recovery? What was the general core configuration and where was the core debris? Why did the thermocouples indicate such high temperatures? Could a rubblized core be cooled?
These questions, all related to core behavior, dealt with both the "what if" and the "what is," and during that 30-day period accurate answers were urgently sought. Answers were forthcoming, but not without some miscalculation and much uncertainty.
It was clear that these questions went beyond the realm of the well-studied design-basis accidents. These uncertainties and miscalculations, which were widely oublicized, were reflected in a lack of public confidence.
There is, therefore, a public and scientific interest in answering the "what if" and the "what is" questions as fully as possible both to olace in perspective the accident that did haopen and to understand the risk of accidents that might happen in the future.
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. The "what is" question can be fully answered by a post-mortum examination of the TMI-2 core, and recommendations for such a coro damage assessment are given below. Since a detailed core damage assessment would not be necessary for Metropolitan Edison's re-covery effort (the entire core will be replacedl, it is appropriate that this assessment be organized and supported as a jotnt industry-government program.
The "what if" question may not be fully answered by an examination of the TMI-2 core, but TMI-2 could be considered as the ultimate in prototypical excerimentation and may yield many imoortant answers.
It is clear from recent blue-ribbon recommendations that the behavior of severely damaged fuel should be better understood in order to know more clearly what margins existed at TMI-2 and in nuclear oower plants in general. This part of the TMI-2 examination also goes beyond a recovery effort and should be a joint industry-government project.
A third area of examination is less directly related to TMI-2 than core damage assessment and the behavior of severely damaged fuel, and this area could be considered as an area of opportunity. TMI-2 should also have resulted in some fuel damage of the kind that is considered in the present design-basis accidents (e.g., fuel cladding ballooning and rupturel. Inasmuch as research programs are currently being funded in 'hese areas to reduce existing uncertainties, TMI-2 23/2 233
,. - examinations would provide an expedient way of making significant progress in these areas. The scientific value of these tests should not be underestimated; it is very difficult in even the most expensive test-reactor experiments to achieve the desired accident conditions in a comercial reactor environment as present in TMI-2.
Many of the individual TMI-2 core measurements will apoly to all three of the above areas of interest. Consecuently there is con-siderable overlac in the recomendations of Working Group 7.2 (Core Camage Assessment and Removal). and Working Group 7.4 (Fuel Experi-ments and Examination), and, in fact, many individuals serve on bath groups. Therefore, the recomendations of these two grouos will be arnrged according to the stage of the operation rather than the objective of the effort, although initial planning was carried out along those lines. Consequently, Working Group 7.2 has provided recomendations for measurements to be made on-site prior to fuel shipment, whereas Working Group 7.4 has provided recomendations for the collection of scecimens and for later laboratory (hot-cell) measurements.
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