ML19209A558
| ML19209A558 | |
| Person / Time | |
|---|---|
| Site: | Crane  |
| Issue date: | 10/01/1979 |
| From: | Arnold R Metropolitan Edison Co |
| To: | Vollmer R NRC - TMI-2 Operations/Support Task Force |
| References | |
| NUDOCS 7910040317 | |
| Download: ML19209A558 (7) | |
Text
.
Metropolitan Edison Company e
Post Office Box 480 Middletown, Pennsylvania 17057 717 944-4041 October 1, 1979 ril-2 Support Attn:
R. Vollmer, Director U. S. Nuclear Regulatory Commission Washington, D.C.
20555
Dear Sir:
Three Mile Island Nuclear Station, Unit 2 (TMI-2)
License No. DPR-73 Docket No. 50-320 Water Storage Assessment As discussed at the Commission meeting on September 28, 1979, TMI Unit II is con-tinuing to experience water inleakage from various operating systems in the Aux-iliary and Fuel Handling Buildings.
This inleakage has been minimized, as much as possible, and is now occurring at a rate of approximately 800-1000 gallons per day.
The leakage is being stored in tankage in Unit II.
At this leakage rate, available Unit II storage capacity will be full in about four to five weeks or about the end of October.
Enclosed is a sumnry of the water inleakage/ storage problem that discusses various options to address the problem.
Based upon our review of the problem as su mnrized in the enclosure, Metropolitan Edison Company reco= mends that Commission authoriza-tion to utilize EPICOR II be given by October 15, 1979.
If appropriate, an initial authorization could be limited to the processing of up to 60,000 gallons.
The Com-pany assumes that authorization will be contingent upon verification by the NRC of completion of those activities currently underway to ensure reliable operation of EPICOR II as discussed with NRC staff personnel at TMI.
Since the system leakage, which is prNarily from non-contaminated systems, can not be tarminated, the Company believes use: of EPICOR II is necessary to prevent unac-ceptable radiological consequences.
We are not requesting authorization to dis-charge any of the decontaminated water but will store the water in tankage until the Environmental Assessment associated with disposal alternatives ordered by the Commission, and its associated review, has been completed.
The Company will be pleased to provide any additional information required.
Sincere',
Vht s R. C. dtrnold Senior Vice President RCA:LWH:rdg
\\
Enclosure
)
' Wcccaan Ec son Ccmca~<.s a '. emce ct tre Genrr arc u :t#s Asp
{O 7010040 l
R. Vollmer October 1, 1979 Enclosure WATER INLEAKAGE OPTIONS AND RECOMMENDATIONS INTRODUCTION Accumulation of water leakage from systems in the Unit II Auxiliary and Fuel Handling 3uildings has been a continuing problem mandating almost daily evaluation of storage options.
Leakage is primarily the result of operation of systems necessary to control plant conditions for reliable removal of decay heat.
The predominant approach to ad-dressing the problem has been to make available a clean up system for processing the
" intermediate tuter" (terminology used to describe waste water having a concentration of Cesium of less than 100jac/ml), EPICOR II, and to minimize the rate at which avail-able storage capacity was utilized by minimizing system leakage.
The use of tanks in-stalled in the spent fuel pool and one tank in Unit I has:.increasaithe available stor-age space.
Despite our best efforts, we are now approaching circumstances which will force a different approach. Within a few weeks, we must either use EPICOR II to pro-cess the Unit II intermediate waste water or provide for storage of contaminated Unit II water by means that have not been acceptable while tankage has been available in Unit II.
This document reviews the various options available and provides the basis for the cen-clusion that use of EPICOR II is the best option. to this document tabulates the current storage status.
displays the recent rate of accumulation of leakage.
The purpose of Attachment 2 is not to provide the basis for a definitive forecast of how soon the available storage will be utilized, but to indicate the magnitude and variation in daily leak rates.
OPTIONS 1.
DO NOTHING.
ALLOW TANKAGE TO OVERFLOW WITHIN THE UNIT II BUILDINGS Tankage overflow will cause the uncontrolled spread of contaminated water back through the Auxiliary Building sump systems and to the building floors.
This will constitute an uncontrolled release of radioactive material, increase the risk of an off-site release of radiation and cause recentamination of dt'uas in the Auxiliary Buildings which have been decontaminated.
The on-site etaff would be subjected to large increases in man-rem exposure.
This course is considerad to be totally unacceptable from the standpoint of protection of the general health and safet'J of the public and the optiod s impact on staf f and site activities.
2.
TRANSFER INTERMEDIATE LIQUID WASTE TO THE UNIT II REACTOR CONTAINMENT BUILDING Transfer of intermediate liquid waste to the Reactor Containment Building is theoretically uossible through existing installed piping (with modification).
The Reactor.ancainment Sullding would provide controlled storage capability.
The disadvc.itages to Containment Building storage are ones associated with the continuing safe operation of the reactor.
A large influx of water would cause additional cooling at low points of the primary system adversely is-pacting natural circulation.
We would immediately require that the decay heat line val'zes presently closed be opened, exposing the pri=sey system to a low pressure (370 psig) setpoint relief valve.
Opening the decay heat line 1089 123 valves would also allow highly contaminated water to enter the decay heat system adversely impacting construction necessary to tie in planned long term reactor cooling systems. We believe the importance of achieving long term stability in the cooling of the reactor render this mode un-acceptable because of its impcct on the activities necessary for long term decay heat removal.
Additionally, modification of installed piping to make the transfer would require removal of check valve internals in high radiation areas (10-20 R/hr) making accomplishment of the modification an exposure and maintenance concern.
3.
TRANSFER INTERMEDIATE LEVEL WASTE TO UNIT I TANKAGE Theoretically about 140,000 gallons of storage ccpacity is available in two of the Unit I bleed tanks.
Permanent piping exists for the transfer of liquid waste.
The trans!c-of water to Unit I, however, poses substantive operational risks.
The Unit I b' eed tanks are required to facilitate repair of the Unit I Borated Water Storage Tank.
The intermediate level Unit II radioactive waste water, containing up to 56 p /ml and 17 ppm chlorides is chemically and radiologically a significant Unit I contamination hazard. With the transfer of water from Unit II, there would even be the potential for contamination of the Unit I pri-mary system.
Transferring water of interme'.iate level activity to Unit I will expand the Unit II health physics problems to Urit I.
The resultant high radiation levels associated with piping, cubicles, and s;orage tanks, make this option very undesirable from a personnel exposure viewpolat. Although necessary procedures and precautions exist to operate safely wit". radioactively contaminated systems, we would be in-creasing the potential for exposing plant personnel to radiation to an extent which has been so far restr;.cted to Unit II.
The potential for leaks exists which would spread contamination to undesirable locations.
Such an occurr ance would expand such problems as Beta contamination to Unit 1.
With this leakage entering the Unit I Auxiliary Building Sump, a potential exists that the activity levels will be too high Specific activity greater than lyc/ml) for processing via EPICOR I System.
The inability to pro-cess would be a compounding problem since then Unit I water would also require storage.
The maintenance of equipment (p ump s, instrumentation, etc.) in con-tact with this water would result in exposures an order of magnitude higher than what Unit I is now experiencing.
Further, this option, which exposes a much larger fraction of the staff to higher radiation levels, is in direct con-flict with the Ccesission's objective for keeping radiation exposure at levels which are as low as reasonable achievable (ALARA).
The transfer of such water also violates the NRC direction to achieve separation of the two units.
Some Unit II water was placed in the Unit I Miscellaneous Waste Holdup Tank (MWHT).
That action was taken recognizing most of tae disadvantages outlined above.
The judgment at the time was that the much lawer specific actfrity of the water to be placed in the tank adequately minimized the adverse consus nces of the transfer.
Any additional water placed in Unit I would have a total spe-cific activity about six times the specific activity of the water in the MWHT and would have a SR69 concentration about 42 times the concentration of SR89 in the MWHT.
1039
?24 4.
TRANSFER LIQUID WASTE TO EPICOR II TANKAGE The EPICOR II waste processing system currently has installed two tanks designed for storage of processed water.
Theoretically, unprocessed water could be stored in either one or both of these tanks.
Doing so, however, would cause radiation levels around the tankage up to about 20 R per hour preventing needed access to the EPICOR II system.
Added shielding would reduce this problem; however, appropriate shielding can not be installed in the available time because the design would have to accommodate severe space limitations.
Additionally, contamination of the clean stcrage tanks would further cause serious operational problems if and when EPICOR II processing is authorized.
5.
STORAGE IN UNIT II B SPENT FUEL POOL The B Spent Fuel Pool is dry and capable of containing radioactive liquid.
The four-foot thick walls provide radiation protection to areas i=sediately outside the pool; however, significant radiation fields would then exist above the pool.
Use of this pool would unjustifiably hamper the implemen-tation of one option, Chem-Nuclear Submerged Demineralizer System (SDS),
under development for the treatment of highly contaminated waste water in the Reactor Containment Building and the Reactor Coolant System.
This system would be installed in the B Spent Fuel Pool.
Should the pool be used, and emptied for installation of the SDS at a later date, the generation of liquids from the decon effort to clean the pool would have additional rad-waste and ALiRA problems.
Although dissolved radioactive gasses =ay be released if the waste water is stored in the open B Spent Fuel Pool, and such releases would pose some risk of exposures and contamination in the Fuel Handling Building and the Unit 1 buildings, the risk associated with this consideration is thought to be minimal.
Nevertheless, ALARA concerns and the adverse impact on the development of the SDS make this option extremely unattractive.
6.
PROCEED WITH INTERDi PROCESSING VIA EPICOR II AND STORE IN EPICOR II TANKAGE This option requires interim processing, without release, using the EPICOR II system.
This syste - 1s designed specifically for the processing of intermediate level liquid waste and could be used within two or three days on an emergency basis.
For a more routine situation, several (about 15) construction " punch list" items should be completed.
In addition, the balance of the emergency procedures should receive final review and approval and additional training for the operators should be completed, including practice operation with clean water, before the system is used for contaminated water.
All of these items are scheduled for completion by mid October.
The system places radioactivity in a stable, well controlled resin bed suitable for ultimate safe disposal.
Processing via EPICOR II can be performed without liquid release from the site.
Radiological consequences of this action both on-site and off-site are considered to be acceptable.
Total integrated man rem exposure to operating personnel would be less than the exposure associated with all other options.
lbb)
I9E as CONCLUSIONS AND RECOEIENDATIONS The continued production of intermediate level liquid waste at Unit II will fill all available Unit II tankage by about the end of October, leading to a potential emergency situation.
This influx of intermediate level wastes can not be terminated.
Public and site health and safety concerns require action to be taken to prevent unacceptable radiological consequences.
It is concluded that the environmental and radiological approach most acceptable is to use the EPICOR II system to process the liquid waste.
The lowest con-tained activity (miscellaneous waste holdup tank and spent fuel pool tank farm) water should be processed first.
The system is expected to process the water such that contained activity would be a factor of 10 below current Technical Specification limitations at the point of entry into the river, if released, and we will try to approach drinking quality water (as defined in the EPA 570).
Decontaminated water will not be released, but will be stored in the EPICOR II storage tanks, or in tanks currently containing the contaminated water, until conpletion of the study of alternatives for dis-posal of the water and approval by the NRC of a disposal method.
1089 126
TMI UNIT II WATER STORAGE SUnfARY (GALLONS)***
Existing Liquid Est. Gross Geometric Usable Level (9/29/79)
Remaining Activity Tank Volume Volune**
(0300)
Caracity uct/ml Tank Farm (Upper Tanks) 60,000 58,328 53,667 h,661 25 Tank Farm (Lower Tanks) 50,000 48,8h2 hl,67h 7,168 25 Misc. Waste Hcidup Tank
- 19,800 19,610 9,21h 10,396 25 Neutraliser Tank A 8,780 8,780 8,780 0
25 Neutrali:er Tank 3 8,780 8,780 8,730 0
25 BC 31eed Tank A 83,h00 77,250 77,250 0
56 RC Bleed Tank 3 83,h00 77,250 77,250 0
56 s;
RC Bleed Tank C 83,h00 77,250 77,250 0
56 Aux. Bldg. Surp Tank
- 3,215 2,6Co 2,600 0
25 Aux. Bldg. Su=p*
11,071 o,000 2,577 6,h23 25 Concentrated Waste Tank 9,000 9,000 9,000 0
25 Misc. Waste Storage 20,300 18,500 18,500 0
h (Unit I) Tank 441,146 h15,190 3e6,542 28,6L8
- Initial processing with EPICORE II would be from these tanks.
- Usable volume is the maximum amount of volume that can be ased in a tank because of operational consideratiens such as overflow piping arrangements.
- Summary is for intermediate level vaste water.
1089 127
=
g; i
A'"TACF4E. It II 7
+
g i
i g
l i
l g
+'
i i
o i,
l i.
0 i
l @
l l
l l
i 9
e" l0 i.
i j
i I
i i
1 i
_g.
e i
l I
O l
i i
i j
' g
=
l j
! G
.O Si i
e I
i i-i i
i i
o" I
l I
G i
i i
o i
i i
i i
i i
i i
i l
l l
t l
l l
l 1
i l
a 5
l i
i l
l i
l i
le i
e
~
0 e
a l
i i
l 1
i i
i i
i0 I
t
~
l I
i l
t m w
~-
I I
l l
I I
l I*
l l
l l
l l
l l
lQ. l9
'l
- o i
i i
l I
I I
l I
i l
l
.-l l
l i s :-
l,i e
'O I
l e
i
't i
i i
i i
i i
9 e
i i
i
'O l
I I
l i
+
lh s.
l f
i i
l l
t j
l 1
t I
?
t i.
i i
,. e e
a i
l I
I I
!O l
l l
Ik i
~
m 1
i I
l i
i l
l I
i l
I iw l
m
!g l
l l
I i
i l
'e l
l
[
l l
O i
i I
i l
I i
i I
l l
l@
l l'i I
[
l 15 I
i i
l l
l l
1 i
i l
i i
l 10 i
I I
i i
I i
i l
l l
I I
ie I 1. I I
i l
1 l
l i
i i
l F
l l
l I
e i
l' O
- 8 l
l l
l l
l l
l l
}
j j
I.
i j
l l
g j
l I
t r a g
l 3
l l~
l l
l l
l l
l l
l-l l
l l
I O i
l S
m <
9 e _. l l
l l
I I
I i
I l
i I
i l
l l
l e
m I
l I
l l
l. I.
I.
l I
l l
l I.
l I
l l
l 6 I
l
~*
l i
l I
i l
i l
i l
i l
l I
l l
1 i
e i
O 3
I l
l l
l l
I I
I l
l l
l i
l l lG I
l l
G l
l l
l l
I l
l
-l l
l I
l I
I O l
I '-
e n
l l
l l
1.l l
l l
l l
I lO l g'. i l
l i
m j
G l
l l
I I
i l.l l
l-l u
t g
i i
i I
l i
a 1
I 1
i j
l i
i o
o-o o
O O
O O
S R
R P00R ORGINAL (CdD) 20Y2Y2'INI CHIC'IInE Ih'rI~I:my 1039
!28 me newN
-6
__----mm-e.
--w%
-,ei.-m-
-wew---,
--m-e.--
ee
-W,
-