ML19247D124
| ML19247D124 | |
| Person / Time | |
|---|---|
| Site: | Sequoyah, McGuire  |
| Issue date: | 02/09/1981 |
| From: | Murley T NRC OFFICE OF NUCLEAR REGULATORY RESEARCH (RES) |
| To: | Ross D Office of Nuclear Reactor Regulation |
| Shared Package | |
| ML19247D089 | List: |
| References | |
| NUDOCS 8102280404 | |
| Download: ML19247D124 (2) | |
Text
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T Docket Nos. 50-327/328 gng gg I @,
t-MEMCRANDUM FOR: Denwood F. Ross, Jr., Director h4%
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Division of Systems Integration V
% D %r FROM:
Thomas E. Murley, Director 4
(s Division of Safety Techrology W I '
,V
SUBJECT:
LOCATION OF IGNITERS IN ICE CONDENSER PLANTS I believe that further analysis is needed to deal with Sandia's concerns on the location of igniters in ice condenser plants. Specifically, they state in MUREG/CR-1752. Rough Craft dated December 1,1980, the follow 1ng:
"Under certain accident conditions, the 1~er corpartment could be inerted either by high concentratiocs o}. team, or by low concentrations of oxygen. If this she0 1 occur, the interim deliberate ignition system (IDIS) as presently planned for Sequoyah has a serious shortcoming. The inerted gas mixture entering the bottom of the ice condensers will emerge as an extremely rich mixture at the top. Concentrations could approach or exceed the detonab'lity limits in a toroidal region around the periphery at the top of the ice condensers.
Four igniters are presantb planned for this region. R strongly reco::nend that those ioniters be removed. Instead, we suggest tnat upper compartment deliverage ignition strategy stould attempt to burn lean mixtures high in the upper compart: ent."
(imphasis added)
If Sandia is correct that igniters are intended to be placed at the top of the ice condensers, then I believe their recomendation should be evaluated in more datail. In my judgment, it is unlikely that we will be able to show that inerted conditions cannot exist in the lower compartment. Sandia states that steam inerting can occur with steam fractions of 30-55 percent, depending on hydrogen r.oncentration. Under these circumstances, we would have to con-sider the possibility of a detonation in the upper plenum.
I don't believe this accident sequence is sufficiently probable that we need to modify our position regarding Sequoyah at this time. However, I believe 810228 0 MOS i
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.s Denwood '. Ross, Jr. TEE e Tis #
we s.tuld evaluate the pros and cons of igniters in the ice condenser upper plenum in mere detail over the coming :aonths, taking into account the results of further testing and analysis we are planning.
Please keep me info'~3ed of your progress on this issue.
WiEi=1 : ;. 2 ; :-.
D.c:es 5. L:n--
Thocas E. Murley, Director Division of Safety Technology cc:
H. Denton D. Eisenhut Distribution Copies:
Docket Files 50-327/328 DST c/f TEM r/f TERA
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