ML19340B803
| ML19340B803 | |
| Person / Time | |
|---|---|
| Site: | Crane  |
| Issue date: | 11/04/1980 |
| From: | Arnold R METROPOLITAN EDISON CO. |
| To: | Harold Denton Office of Nuclear Reactor Regulation |
| References | |
| TLL-541, NUDOCS 8011120310 | |
| Download: ML19340B803 (4) | |
Text
.
t Metropolitan Edison Company 9
Post Office Box 480 Middletown, Pennsylvania 17057 Writer's Direct Osal Number November 4,
1980 TLL 541 7g
~d Of fice of Nuclear Reactor Regulation Harold R. Denton, Director
[
U.S. Nuclear Regulatory Commission Washington, D.C.
20555 0 _.,
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Dear Sir:
N E.
f g
a Three Mile Island Naclear Station, Unit II (TMI-2)
Operating License No. DPR-73 Do cke t No. 50-3 20 Contingency Plan for Transfer and Storage of Reactor Containment Building Sump Water This letter is in response to your letter dated August 6, 1980, and f ulfills our commitment made to :ou via cur letter TLL 416, dated August 22, 1980, supplemented by our lett at TLL 550, dated October 17, 1980, to provide a contingency plan for fra :sfer of the contaminated water presently in the reactor building containment sump. This plan has been developed to icentify existing locations that are acceptable under emergency condi-tions for storage of that water should an emergency require removal of the water from the reactor containment building sump.
This plan considers the use of presently installed equipment for storage and transfer.
Our conclusions are as follows:
1.
Storage locations exist within the plant to accom=odate the entire quantity of sump water in the event of emergency conditions.
2.
Transfer paths can be made available to transfer the water from the sump to a chosen storage location.
3.
Transfer of the water may adversely impact the overall safety of plant ope ra tio ns.
4.
Should it be necessary to use IMI-1 tankage as sump water storage overall radiological safety of Unit 1 operations would be adversely impact ed.
E03 312 0 N Metreco.. tan Ed' son Ccmpany :s a Memter et me General Pucoc Ut.a es System
l
)
H. R. Denton TLL 541 4
5.
The most prudent course of action to follow is to continue ef forts to ready the Submerged Demineralizer System for operation to enable processing of the contaminated water in the reactor j
building sump at the earliest possible date.
This plan has been developed to ensure that acceptable action can be carried out in the event that leakage paths from the containment sump develop. Should a leakage path occur that jeopardizes the health c. I safety of either the public or our plant workers, this plan would be implemented.
3 In the event of an emergency requiring the transfer of water from the reactor building sump prior to processing, the following potential storage
" sites" listed in order of suitability, have been identified:
Capacity J
1.
Reactor Coolant Bleed Hold Up Tanks, (RCBT) Unit 2 231,750 gallons 2.
Tank Farm in Unit 2 "A" Spent Fuel Pool 110,000 gallons i;
3.
Reactor Coolant Bleed Hold Up Tanks, Unit 1 247,000 gallons 4.
Spent Fuel Pool "A", Unit 2 320.000 gallons i
TOTAL 908,750 gallons The total volume of radioactive water in the reactor building sump is approximately 600,000 gallons. This water inventory is increasing at the rate of approximately 4500 gallons per month.
The total volume as indicated above for each " site" may not necessarily be immediately available. However, should the requirement to utilize the " sites" listed above become mandatory, the available volume could be increased by processing the water via EPICOR-1 or EPICOR-2 that may currently exist in any specified storage location.
The above listing of " sites" has been detecnined based on the considerations identified below:
1.
Available volume for storage is adequate to accommodate the total volume of sump water.
Increased radiation level in the vicinity of the projected storage 2.
locations can be accasmodated, although this ef fect is highly undesirable. In particular, capability to perform maintenance of j
equipment and instrumentation in the cubicles containing the Bleed Hold Up Tanks will ha severely impacted.
,,m
O H. R. Denton TLL 541 3.
The chosen transfer path makes use of existing components and piping.
4.
The transfer paths traverse plant areas that are amenable to the control of personnal radiation exposure during the tr ans f e r.
The tank farm located in the Unit 11 Fuel Pool and the RCBT's in Unit II provide a total potential storage capacity of 341,750 gallons. The use of these two " sites" would require additional radiological precautions for storage and transfer of the sump water. Use of these storage locations appears to be acceptable from a shielding, and hence radiological exposure to workers, view-po in t, with the exception of inhibited capability to perform maintenance acti-vities in the Bleed Hold up Tank cubicles mentioned previously. Transfer paths from the sump to these storage locations traverse areas of the plant that may be occupied by personnel on an as-needed basis. During transfer evolutions, access to these locations would have to be strictly controlled and would result in inaccessible plant areas until the transfer piping was flushed.
The THI-1 RCBT's provide a potential storage capacity of 247,000 gallons and are an additional storage location that could be made available should it be necessary to transfer additional sump water. Use of these tanks suf fer from the same disadvantages as use of TMI-2 RCBT's.
Although the use of these tanks fo r the storage of the sump water is undesirable because of unit separation and our desire and intent to contain the TMI-2 accident water within the confines of TMI-2, the tanks can be used for this purpose because they are shielded and because their volume is suf ficient for storage of most of the remainder of the water.
Because power operation of Unit I requires that at least two RCBTs be available to provide a source of makeup to the reactor coolant system, and because we consider it highly undesirable to introduce THI-2 accident generated water into 23I-1 systems, we will be exanining actions which will mitigate the adverse impact of utilization of the Unit 2 spent Fuel Fool "A" as a storage site.
This is especially impo rtant since that pool is likely to be needed to store some amount of water even if the Unit 1 RCBT's are used. The adverse impact of utilization of Unit 2 Spent Fuel Pool "A" include:
1.
Personnel radiation exposure in the Fuel Handling Building would be increased. Our analysis provides results that indicate that the radiation level in the center of the shielding atop the "A" Spent Fuel Pool would be approximately 10 mrem /hr with 320,000 gallons of sump water in the po ol.
2.
The potential for airborne contmaination, as a result of storage of sump water in the Spent Fuel Pool, and subsequent Lacrease in plant ef fluents of gaseous and airborne particulates may exist. To minimize the possibility of this occurrence, the Spent Fuel Fool area cover can be sealed to minimize communication with the Fuel Handling Building atmosphere.
4 H. R. Denton TLL 541 l
As a result of our development of this contingency plan, we conclude that:
1.
Potentially available volume exists that can be used for the storage of reactor containment building sump water in the unlikely event that emergency conditions dictate its removal from the sump. However, it must be recognized that each storage location has unique and significant disadvantages asso-ciated with it.
2.
Transfer paths are available to transfer the water from the sump to the selected storage location.
I We wish to reiterate our belief that the best approach to this problem is processing of the reactor building sump water. To this end, we are proceeding with construction and start-up testing of the Submerged Demineralizer System.
This system is currently scheduled to be available for operation in late March, 1981. We urge that the NRC proceed expeditiously in providing the necessary regulatory approvals to permit operation of this system.
d Sincerely,
^
R. C.
ld Chief Operating Executive RCA:b e cc:
J. T. Collins B. J. Snyder
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