ML19323B662
| ML19323B662 | |
| Person / Time | |
|---|---|
| Site: | Crane  |
| Issue date: | 04/07/1980 |
| From: | Lipkin D AFFILIATION NOT ASSIGNED |
| To: | Chilk S NRC OFFICE OF THE SECRETARY (SECY) |
| Shared Package | |
| ML19323B642 | List: |
| References | |
| RTR-NUREG-0662, RTR-NUREG-662 NUDOCS 8005140041 | |
| Download: ML19323B662 (8) | |
Text
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8 005140g D 2 6 2.
a-TESTIMONY ON DECONTAMINATION OF THE THREE-MILE-ISLAND UNIT-2 REACTOR BUILDING'S ATMOSPHERE TO:
The U.S. Nuclear Regulatory Commission (N. R.C. )
j 1717 H Street, N.W.
3r Washington, D.C.
20555
-fr
/
s-FROM:
Daniel M.
Lipkin, physicist 1717 Bantry Drive (215)-646-7522 Dresher, Pennsylvania 19025 ATT'N:
Samuel J. Chilk, Secretary, N.R.C.
DOCKET No.:
50-320 DATE:
April 7, 1980 also ATT'N:
Director, TMI Support Staff, N.R.C. Office of Nuclear Reactor Regulation (N.R.R. )
'g'
-Harold R. Denton, Director, N.R.C./N.R.R.
John T.
Collins, Jr., Chief, N.R.C./N.R.R.
Effluent Treatment Systems Branch Robert J.
Budnitz, Director, N.R.C. Office of Nuclear Regulatory Pescarch John F. Ahearne, Chairman, N.R.C.
Peter A.
Bradford, Commissioner, N.R.C.
Victor Gilinsky, Commissioner, N.R.C.
Joseph M. Hendrie, Commissioner, N.R.C.
Richard T.
Kennedy, Commissioner, N.R.C.
other cc:
additional distribution as per attached list.
REFERENCE:
N.R.C.
Document NUREG-0662, " Environmental Assessment for Decontamination of the Three Mile Island Unit 2 Reactor Building Atmosphere".
Hyphenated-page loca-tions noted in the text below refer exclusively to i
that document.
l
Dear Sirs:
Your referenced document NUREG-0662 indicates great difficulties of four different methods for removing Krypton gas contamination from the TMI Unit-2 Reactor Building, in comparison with the technically simple alternative of venting that gas into the public air space.
My testimcny will show that one of those four methods, based on the admittedly feasible (page 1-6) use of charcoal to adsorb Krypton gas, has been unimaginative 1y if not clumsily conceived in both of,the versions described (pages 6-9 to 6-16), and should be capable of i
approximately twenty times greater simplicity if modified in ways that should be obvious to those skilled in the technical arts involved.
As a citizen, I am greatly disappointed at this performance of agencies 1
that have been invested with the public trust.
For the purpose of my discussion, and essentially only by way of illustration, I shall take as a goal the reduction of the Krypton con-j centration in the TMI Unit-2 Reactor Building's Atmosphere (henceforth, "TMI-2" or just plain "R2") to 1/100 of its present value.
This does not represent an ultimate limit of relatively simple applications of page 1 of 8 pages
g U.S. N.R.C.
TESTIMONY April 7, 1980 the charcoal-adsorber technology involved; and it does not approach the idealized goal of 100,000:1 reduction of the Krypton concentra-tion that is implicitly adopted in NUREG-0662 (data on pages 3-1 or 5-2, plus data on pages 6-2 or 6-28; consistent with data on page 6-13).
But a reduction by "merely" 100:1 would provide a useful and practical solution of the Krypton contamination problem:
At present, approximately 1/4 of the gamma radiation that would affect workers inside TMI-2 is indicated as being caused by sources other than the Krypton gas (page 4-2) ; therefore, a 100:1 reduction in the concentration of the Krypton gas would bring its gamma radiation down to a level 33 times smaller than that of the other (and unventable) sources of gamma radiation already in the reactor building, and would thus constitute a quite handsome improvement of the situation.
In a proper use of charcoal adsorber technology, important advantage can and should be taken of the fact (stated on page 6-9 but not exploited in NUREG-0662) that charcoal loses its ability 3
to adsorb Krypton if it is exposed to even moderately small levels of humidity.
This fact permits previously adsorbed Krypton to be largely flushed out of a charcoal tank if desired, and thus permits Krypton gas to be transferred between a small number of such tanks in a controlled manner.
Such transfers, if programed in a readily understood manner, will in principle permit the available Krypton to be concentrated with a high degree of precision into a single one of the tanks.
Proper engineering insight can thus eliminate any need to consider the monstrous scenario of hundreds of charcoal adsorber tanks (page 6-13) that is painted in NUREG-0662.
7 I shall consider refrigerated charcoal adsorber to be used, maintained at an ordinary food-freezer temperature of 0 0F.
(page 6-11) whenever it is in the process of being used to adsorb Krypton from suitably conditioned air (completely dehumidified and dried air pages 6-9, 6-10).
In that context, the charcoal adsorber scheme described in NUREG-0662 is stated to require the use of 150 charcoal-a containing tanks (page 6-13), each of volume 42,300. gallons (implied on page 6-10).
This number, 150, of such tanks does not, however, serve as a fair basis for comparison, because it corresponds to much more than the targeted 100:1 reduction in the Krypton concentration in R2.
It can readily be shown that 59 or 60 of such tanks would, however, be needed for a 100:1 reduction of the Krypton concentration by the refrigerated-charcoal adsorber method described in NUREG-0662, and this does provide a fair starting figure on which to base compar-inons.
By contrast with this last, approximate figure of 59 or 60 l
tanks of charcoal, the method that I shall describe requires the use of only 3 separate tanks of charcoal of the individual size indicated, and therefore presents a dramatically different picture as regards practicality.
Consider there to be provided three separate bodies of charcoal adsorber, each having,the single-tank volume already indicated, and
~
designate them as L, M, and N for brevity.
A Krypton " transfer" cycle, utilizing two of these three charcoal bodies, is executed in three steps, as follows:
(a)
Filtered, dried, and heated air from the reactor building R2 is circulated through the first charcoal body, L, and returne'd to R2 in a closed circuit of air flow, as a preparatory step, page 2 of 8 pages
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C x
U.s. N.R.C.
TESTIMONY April 7, 1980 to remove any moisture that the body L may contain.
(Both in this step and in the step (b) that follows, a net preponder-ance of cooling would be applied to the air returning to R2, to avoid any rise of the air pressure inside R2, and indeed to forestall or compensate such a rise of pressure due to any outsidi causes.)
(b)
When L is dry, the closed-circuit flow of air between R2 and L is continued, but now the filtered and dried air entering L is not heated, but instead is refrigerated to 0 0F., to cool L down to that temperature and permit it to adsorb Krypton gas maximally well (page 6-10) from the R2 air flowing through it.
(c)
When L has come to equilibrium in its Krypton content and will adsorb no further Krypton (i.e., when " breakthrough" occurs
-- page 6-10), valves are operated to disconnect L from R2 and to connect L instead to the second charcoal body, M, which has previously been dried and refrigerated to 0 0F.
Closed-circuit air flow is now established between the two charcoal bodies L and M, with the following special provisions:
c.l.
The air that is to enter M is first dried and refriger-ated, to maintain M at 0 0F. and permit it to adsorb Krypton maximally well.
(No moisture, or heat, are l
Introduced into M during any part of a transfer cycle.)
l l
c.2.
The air tnat is to reenter L is heated and humidified, to cause L to lose its ability to adsorb Krypton (page 6-9), and thus in effect to flush out nearly all of its adsorbed Krypton into the circulated air, from whence the Krypton is available to be adsorbed by M.
l In the course of effectuating the provisions c.1. and c.2.,
l the heat and the moisture that are removed as waste from the circulated air before it is allowed to enter charcoal body M are shunted back usefully to aid the process of heating and humidifying the air entering L.
The combined process c l.,c.2.
l causes the Krypton initially present in the charcoal bodies l
L and M to become preponderantly concentrated into M, and l
largely removed from L; this process is allowed to run to completion as measured by stabilization of the Krypton-85 radioactivity levels in the respective bodies L and M, after which the communication between L and M by air flow is disconnected.
1 Repetition of the transfer cycle (a)- (b)- (c) continually trans-fers Krypton from R2 to L, and then from L to M as a temporary recei-ver, leaving the charcoal body L depleted in its Krypton content at the end of each transfer cycle and therefore able te adsorb more Krypton from R2 during the next such cycle.
j By using available information concerning the initial Krypton-85 radioactivity in R2 (pages 3-1, 6-37, 6-5, 5-2), and concerning the amount of this radioactivity that can be adsorbed into a first tank of refrigerated charcoal adsorber (page 6-13), and by further assuming l
l page 3 of 8 pages
.g U.S. N.R.C.
TESTIMONY April 7, 1980 cess drives most of the Krypton out of M and concentrates it into N, and is continued until it reaches completion.
(At this point, the charcoal body M contains moisture, which must be removed before M can resume participation in transfer cycles.)
(e )
The charcoal bodies L and M are next placed into closed-circuit circulated-air communication with one another, and heated air is circulated through both of them, the circulated air being, however, dried before entering M (moisture that is removed as waste from the air stream before it enters M is shunted back to L).
T.his process dries any moisture out of M, and traps the moisture in L.
6 (f)
After M is dry, the closed-circuit circulation of air between L and M is continued, but the air is now both dried and re-frigerated before it enters M, and is heated and humidified before it reenters L, just as in step (c) of a transfer cycle.
This ensures that most of the residual Krypton in L and M will be concentrated into M, and completes the reconditioning of M to a dry, cold state suitable for use in a resumption of the transfer-cycling (a)- (b)-(c).
If the processes of transfer-cycling and of storage-cycling, that have been described as a means for extracting Krypton from the building R2, seem complicated, it is only because I have attempted some precision in describing them:
they are actually quite simple from a technical standpoint.
Thus, the combined total volume occu-pied by the charcoal in all three of the adsorbing bodies, which is about 17,000 cubic feet, is only the air volume in a medium-to-large-size private home.
The physical operations that are essential to the decontamination process under discussion are only the heating of air, the cooling of air, the humidification of air, the dehumidification and drying of air, and the forced circulation of air, all of which are common technology.
As to forced flow of air out of the building R2 for the described purpose of closed-cycle circulation, a flow rate of 1000 cubic feet per minute (CFM) of filtered air represents a capability that is already (page 6-1) being installed at TMI-2 as part of the proposed " purge" system for venting the Krypton.
Although an air flow rate of 1000 CFM represents less than what is commonly used in single-home central air-conditioning, it is still adequate to mqve 2,000,000 cubic feet of air (one reactor building's content) five times in a week -- and to change the air in one of the charcoal adsorber bodies under discussion more than 10 times in an hour.
Be-cause the Krypton decontamination process under discussion involves rather large and abrupt temperature changes of circulated air, the heat or cold supply rates that are involved do need to be much larger than those involved in single-home central air-conditioning; but the supply rates can be minimized by using well known counter-flow heat-exchange techniques affecting waste heat or cold, and, at any event, should not prove larger than those required for, say, a supermarket (if indeed suitable facilities do not already exist in some unrecog-nized form at the site).
With the immediately preceding discussion of air flow rates and the like, as background for a preliminary understanding of the degree of difficulty or simplicity of the Krypton decontamination method I have described, the performance that can be expected for that method page 5 of 8 pages
U.S. D.R.C.
TESTIMONY April 7, 1980 is descr.Lbed, and conservatively described, I believe, by the num.
bers given in the accompanying Table 1.
In Table 1, the first col-umn counts the process cycles that are gone through; the second col-umn tells the type of each process. cycle; and the remaining four columns predict the amounts of Krypton that will exist in the reactor building R2 and in the three charcoal adsorber bodies L, M, N at the end of each cycle; those Krypton amounts are expressed to three sig-nificant figures, as decimal fractions of the total amount of Kryp-ton initially located in the reactor building.
As is shown by the third column of Table 1, on line 77, the Krypton concentration in the reactor building R2 should be down to below 1% of its initial value, after 77 cycles have been performed.
At a processing rate of perhaps four cycles per day, the entire Krypton decontamination of R2 could therefore take less than 3 weeks from start to finish.
In discussing the foregoing example of a practical Krypton decontamination method, it is not my intention to suggest, as NUREG-0662 does (pages 6-9 through 6-14), that the charcoal adsorber tanks be used for permanent storage of the Krypton removed from the reactor building.
Instead, the adsorbers should only be regarded as a tempor-ary storage means for the Krypton, until such time that it can be dealt with by methods permitting its greater concentration for final disposal by burial, but requiring longer times to implement (e. g.,
pages 6-23, 6-32).
This provision of temporary storage would suffice l
to accomplish the primary public-safety goal of permitting expeditious access to the damaged #2 reactor core for the purpose of safe disas-I sembly of that core; and it would do so without risking the.public distress (pages 1-3, 6-7) that might attend venting of the Krypton gas.
I I hope that the discussion and analysis presented here may 1
straighten out the perspective from which the Krypton decontamination problem is viewed, and prove useful in expediting an acceptable solu-4 tion to that problem.
Sincerely yours, d.t LV.
',, U L.<
Daniel M. Lipkin, physicist page 6 of 8 pages
U.S. N.R.C.
TESTIMONY April 7, 1980 TABLE 1:
Estimated Progress of the Krypton Decontamination Ordinal Type of Fractional Krypton Amounts at End of Cycle No. of Process in Reactor in First in Second in Third Process Cycle
- Building, Charcoal Charcoal Charcoal Cycle (see text)
"R2"
- Body, "L"
- Body, "M"
- Body, "N"
O (initial state) 1.000 0.000 0.000 0.000 1
transfer 0.925 0.00129 0.0742 0.000 2
transfer 0.856 0.00245 0.142 0.000 3
transfer 0.794 0.00351 0.203 0.000 4
transfer 0.737 0.00448 0.258 0.000 5
transfer 0.686 0.00536 0.309 0.000 6
transfer 0.639 0.00615 0.355 0.000 7
transfer 0.596 0.00688 0.397 0.000 8
transfer 0.558 0.00753 0.435 0.000 9
transfer 0.523 0.00813 0.469 0.000 10 storage 0.523 0.000275 0.0158 0.461 11 transfer 0.483 0.000942 0.0544 0.461 12 transfer 0.448 0.00155 0.0893 0.461 13 transfer 0.415 0.00210 0.121 0.461 14 transfer 0.386 0.00260 0.150 0.461 15 transfer 0.359 0.00306 0.176 0.461 16 transfer 0.335 0.00347 0.200 0.461 17 transfer 0.313 0.00384 0.222 0.461 18 transfer 0.293 0.00419 0.242 0.461 19 transfer 0.275 0.00450 0.260 0.461 20 storage 0.275 0.000286 0.0165 0.709 21 transfer 0.254 0.000634 0.0366 0.709 22 transfer 0.236 0.000951 0.0549 0.709 23 transfer 0.219 0.00124 0.0715 0.709 (etc.)
Sh transfer 0.0149 0.00b445 0.0b57 0.959 (9
transfer 0.0141 0.000457 0.0264 0.959 7c storage 0.0141 0.000294 0.0169 0.969 71 transfer 0.0134 0.000307 0.0177 0.969 72 transfer 0.0126 0.000319 0.0184 0.969 73 transfer 0.0120 0.000331 0.0191 0.969 74 transfer 0.0114 0.000341 0.0197 0.969 75 transfer 0.0108 0.000350 0.0202 0.969 76 transfer 0.0103 0.000358 0.0207 0.969
- 77 transfer 0.00989 0.000366 0.0211 0.969 78 transfer 0.00948 0.000373 0.0215 0.969 79 transfer 0.00911 0.000379 0.0219 0.969 80 storage 0.00911 0.000294 0.0170 0.974 81 transfer 0.00869 0.000301 0.0174 0.974 82 transfer 0.00832 0.000307 0.0177 0.974 83 transfer 0.00797 0.000313 0.0181 0.974 page 7 of 8 pages n --_
U.S. D.R.C.
April 7, 1980 Distribution Lint The Hon. Richard L. Thornburgh, Governor Commonwealth of Pennsylvania Main Capitol Building Harrisburg, Pennsylvania 17120 Dr. Robert D.
Pollard Dr. Henry W.
Kendall Union of Concerned Scientists Union of Concerned Scientists 1725 I Street, N.W.- Suite 601 1208 Massachusetts Avenue Washington, D.C.
20006 Cambridge, Massachusetts 02138 Jack H. Watson, Jr., Cab.Sec'y.
Charles Warren, Chairman i
The White House Office Council on Environmental Quality
{
1600 Pennsylvania Avenue, N.W.
722 Jackson Place, N.W.
Washington, D.C.
20500 Washington, D.C.
20006 National Commission on Air Quality President, Metropolitan Edison Co.
499 S. Capitol Street, S.W.
P.O. Box 542 Washington, D.C.
20003 Reading, Pennsylvania 19640 Douglas M. Costle, Administrator U.S. Environmental Protection Agency -- A-100 401 M Street, S.W.
Washington, D.C.
20460 i
f David Hawkins, Ass't. Admin./A,N,R. John Russell, Chief U. S.
E. P. A.
En.& Fac. Eval. Br., O.R.P.
401 M Street, S.W.
U.S. E.P.A. - ANR 459 Washington, D.C.
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20460 U.S.
Senator John Heinz U.S.
Senator Richard S. Schweiker 4327 Dirksen Senate Office Bldg.
253 Russell Senate Office Building Washington, D.C.
20510 Washington, D.C. 20510 U.S.
Repr. Lawrence Coughlin State Senator Stewart J. Greenleaf
)
306 Cannon Office Building 306 Wyncote Road I
Washington, D.C.
20515 Jenkintown, Pennsylvania 19046 State Representative Vern Pyles Lawrence H.
- Curry, 3239 Pebblewood Lane Montgomery County Commissioner Dresher, Pennsylvania 19025 Courthouse, Norristown, PA 19404 Louise Bradford, Staff Gail Bradford, Staff Three-Mile-Island ALERT March 28th Coalition 315 Peffer Street 1037 Maclay Street s
Harrisburg, Pennsylvania 17102 Harrisburg, Pennsylvania 17103 Lt. Gen. John W. Morris Prof. Ernest J.
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4 page 8 of 8 pages
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