ML19340F198
| ML19340F198 | |
| Person / Time | |
|---|---|
| Site: | Susquehanna  |
| Issue date: | 12/29/1980 |
| From: | Krug H Office of Nuclear Reactor Regulation |
| To: | Houston R Office of Nuclear Reactor Regulation |
| References | |
| NUDOCS 8101210297 | |
| Download: ML19340F198 (6) | |
Text
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'o UNITED STATES
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WASHINGTON, D. C. 20555
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DEC 2 91980 u
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MEMORANDUM FOR:
R. Wayne Houston, Chief Accident Evaluation Branch Division of Systems Integration l
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THRU:
T. R. Quay, Leader u
Systems Analysis Section, AEB FROM:
Harry E. Krug Systems Analysis Section, AEB
SUBJECT:
MINUTES OF CONTROL ROOM HABITABILITY MEETING HELD NOVEMBER 18 & 19, 1980 IN BETHE.SOA The meeting minutes are enclosed along with an attendance list. The persons receiving a copy of these minutes include all attendees plus those indicated on this memo.
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- rug, Systems Analysis Section Accident Evaluation Branch Division of Systems Integration cc: S. Ramos, NRC J. Dodds, Bechtel 81012102_%
MINUTES OF THE MEETING WITH PNL AND OTHERS ON CONTROL ROOM HABITABILITY The control room habitability meeting was held on. November 18 and 19,1980, in Bethesda as scheduled. A list of attendees is given in Enclosure I.
The purpose of the meeting was to:
- 1. discuss apolicability of the Bechtel ;ontrol room X/Q formulation to the Susquehanna station and the potential applicability of this X/Q formulation to other plants; k.discussPacificNorthwestLaboratory'sprogressonthecontractforcontrol room habitability evaluations as required by Task Action Plan (TAP) item.
III.D.3.4 (" Control Room Habitability") of NUREG-0660.
Sumary for November 18, 1980 I. THE X/0 FORMULATION Two concerns were raised concerning the X/Q formulation by the meteorlogy specialists present:
- 1. a more approcriate. value of the coefficient "K" might be 4 or 5 rather than 2 as used by Bechtel; and
- 2. the X/Q formulation may not be applicable at certain angles from the normal to.the front of building. Wind at these angles may result in concentration levels higher than what would be predicted by the various models. Specifically, with respect to the Susquehanna plant, the X/Q fomulation problems arise, in.
part, because of the close proximity of the single control room inlet to the back of the reactor building. It appears that a generic formulation capable of accounting for such close-in receptor points may be at least a few years off.
Further, it was felt that the best. hope.for u.: adequate quantitative evaluation of the as-built configuration may be produced through wind tunnel tests.
Discussion of the wind tunnel tests made it clear that the test geometry and conditions would have.to be carefully and completely designed. It would ba prudent to seek approval in advance of such a specific test from NRC.
Nevertheless, it was believed that such a test, including.an. adequate number of wind direction angles, could be performed for less than $50,000.000, i
The sense of the grcup was that such a test might show that the as-built configuration at Susquehanna is acceptable. Presumably if the existing control l
room intake location were found unacceptable, it would be prudent if the test provided definitive information concerning acceptable locations for an l
additionalinlet(s).
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, The possibility of achieving an acceptable geometry at Susquehanna by simply increasing the height of the SGTS stack was discussed. This option may well provide one acceptable solution. Clearly,if a properly built stack were "very tall", the configuration would be found to be acceptable. Estimation of the proper height of the stack was not pursued, in part, because of concern that, during startup of the STGS at the beginning of a postulated accident diffuse leakage (which short-circuits the STGS vent to the atmosphero outside the reactor building) will occur.
In the case of ?he Susquehanna statian, there appear to be a number of good engineering reasons why this assumption may be unduly conservative. This option, however, could be evaluated further, and it is possible that a higher stack may provide an acceptable solution.
The applicability of the X/Q formulation as proposed by Bechtel to control room ventilation intake locations experienced at other plants is questionable.
Within the next two weeks, PNL will consumate, with NRC concurrence, a sub-contract with Ray Hosker of ORNL to assist in the review of generic formulations on control room X/Q's.
In addition, within the same time frame, Mr. Hosker has agreed to: (1) document his comments concerning the applicability of the Bechtel X/Q formulation to the Susquehanna station, and to (2) provide some preliminary information comparing the Bechtel, Wilson and Murphy-Campe X/Q models. This information is expected to be generated as part of the subcontract to PNL.
Mr. Hosker indicated that the Murphy-Campe correlation.was conservativ'e and that while the Wilson correlations were also conservative, it is more realistic than the Murphy-Campe model.
Our present perception is that the review of the operating reactor cpntrol room X/Q under III.D.3.4 will result in the identification of plants in three categories: (1) acceptable, (2) not acceptable and (3) questionable.
It is the consensus of the committee that a task force of three to five principals, including strong representation by those. expert in the interpretation of wind tunnel test results, can perform rapid evaluations (given adequate information).
PNL has agreed to provide drawings and projection positives of the questionable cases for the review and discussion.
1 Although the exact protocol has not yet been established, the current thinking is that the review of the questionable cases will identify those that are acceptable and those which will require additional modification before accept-ability can be judged. In the latter case, suggested modifications may be identified. For the acceptable cases, a lower-limit on the control room X/Q will be specified by the task force.
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. II. WIND TUNNEL TESTS The connittee indicated that wind tunnel tests for understanding air flow patterns in terrain containing structures is as much art as science. For some structural. configurations, small variations in incident air flow angles can give large variations in the X/Q's. Thus the effects of wind directions must be thoroughly examined in the tunnel.
Recent information indicates that Halitsky's tests were too laminar, yielding wake effects which.were too wide, and underestimating the effects of building reattachment zones.. Generally speaking, however, Halitsky's results are more condarvative than the recent results for those incident angles measured by Halitsky. Unfortunately, as the case of Susquehanna points out, the application of simple correlations to certain as-built configurations is not meaningful for all wind directions of interest. Further clouding t%e applicability of simple calculations, in some cases, is the presence of cooling towers and terrain features of significant size to make the application of a generic formulation questionable.
With respect to the value of wind tunnel test data, the attendees pointed out that flow field studies should be performed along with concentration measurements.
Being able to compare the two allows much greater confidence in the results.
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, Summary for November 19, 1980 Dennis Murphy and Harry Krug met and discussed the status of the PNL contract for Control Room Habitability and also discussed the meeting of the previous day.
Staff comments on the proposed PNL review check list and evaluation sunnary letters were discussed. Mr. Murphy agreed to initiate a subcontract with Ray Hoskins of NOAA within the next two weeks to: assist in the generic formulations of X/Q's, document his comments concerning the applicability of the Bechtel X/Q formulation to the Susquehanna station, and to provide some preliminary informa-tion comparing the Bechtel, Wilson and Murphy-Campe X/Q models.
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1 List of Attendees - - Meeting of November 18 & 19, 1980 Name Organization Harry Krug NRC/DSI/AEB Ted Quay NRC/DSI/AEB Dennis Murphy Battelle PNL Bob Scherpelz Battelle PNL Jerry Sagendorf NOAA/ARL Ron Orake Battelle PNL Earl Markee NRC/DSI/AEB Ray Hosker NOAA/ATDL (Oak Ridge)
Ken Mur'phy NRC/DSRR Kazanieras Campe NRC/SAB Frank Akstulewicz NRC/DSI/AEB Leta Brown NRC/OSD Robert Kornasiewicz NRC/0SD i
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