ML20062D399

Forwards Radwaste Reduction Info Sys.Sys Does Not Involve Unreviewed Safety Questions Based on Fact That No Equipment in Radwaste Bldg Is Important to Safety.Bldg Sched to Begin Feb 1979 & Be Completed by Oct 1980

ML20062D399
Person / Time
Site:	Nine Mile Point
Issue date:	09/01/1978
From:	Dise D NIAGARA MOHAWK POWER CORP.
To:	Ippolito T Office of Nuclear Reactor Regulation
Shared Package
ML17053A245	List: ML20062C723 ML20062D396 ML20062D399
References
NUDOCS 7811220193
Download: ML20062D399 (12)

Text

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.4 -.- ' M VMIAGARA

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rvUMOHAWK .

NtAGARA MOHAWK POWER CORPORATION /300 ERIE BOULEVARD WEST. SYRACUSE. N.Y.13202/TELEPbCNE 1315i 474 -

September 1, l'978 1

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Director of Nuclear Reactor Regulation .

Attn: Mr. Thomas Ippolito, Chief - -

_.... _ _ .. ..._ _ .._._. . Operating Reactors -

Branch #3 .

U. S. Nuclear Regulatory Commission Washington, D. C. '20555 '-

e s Gentlemen: -

Re: Nine Mile Point Unit 1 Docket No. 50-220 DPR-63 Niagara Mohawk Power Corporation plans to install a Radwaste Reduction System and associated waste handling equipment at Nine Mile Point Unit 1.

The advantage of the Radwaste Reduction System will be to decrease the amount of solid waste that is shipped to I

offsite burial grounds. The System is expected to achieve an overall volume reduction factor of about 10. This will result in fewer shipments of radwaste, will extend the existing space at offsite burial grounds and result in handling fewer radwaste containers.

The Radwaste Reduction System information contained herein as Attachment A is submitted in accordance with the requirements of 10CFR20.305. Additionally, Attachment A contains description of the associated waste handling equipment for your information. ,

l The associated waste handling equipment will be capable of solidifying waste without operation of the Radwaste ,

Reduction System. Design of the associated handling systam will proceed independently of the Nuclear Regulatory Commission review of the Radwaste Reduction System.

An evaluation was made relative to 10CFR50. 59 (a) and it was concluded that the Radwaste Reduction System and associated iaste handling ecuipment do not involve an unreviewed safacy c,uestica since:

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(1) The probability of occurrence or the consequences of an accident or malfunction of equipment important to safety previously evaluated in the safety analysis report will not increase and (2) The possibility for an accident or malfunction u of a different type than any evaluated pre-viously in the safety analysis report will ,

not be created; and .

(3) The. margin of safety as defined in the i basis for any technical specification will

.not be reduced. . .

- These c'nclusions o are based on the fact that none of

. the equipment to be contained within the radwaste building is

important to safety. Analyses have been performed assuming

- release of the mav4mn= amount of incinerated, but non-solidified radwaste on-hand. The results show that only the~ building structure is important to safety. This structure will be equal to or better than the existing -

_radwaste building in terms of probability or consequences of failure. The building will be a. seismic Class I Structure. -

No neu accidents will be introduced other than different types of postulated handling accidents within the building structure. Releases from such accidents have been demonstrated to be insignificant when compared to failure of the building

" structure analyzed herein.

These modifications do not involve any changes to

- the, Technical Specifications. No Technical Specifications are' affected by these modifications.

Waste processed by the Radwaste Reduction System will be no different from those previously described in the Final Safety Analysis Report. These wastes include:

.1) Filter sludges Deep bed and powdered deminerali=er resins

2) .

Concentrated waste

~3) .

- 4) Filters, paper, wood and other combustible materials which may have been radioactively ' "

contaminated.

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. e The Radwaste Reduction System will be housed in a building adjacent to the existing waste building on the east side of the plant. This building will also contain the solidification and handling equipment necessary to process the product for final offsite shipment. Building dimensions will be about 60 feet by 270 feet. The building will be designed to the Class I seismic requirements described in the Final Safety Analysis Report. -

Any spillage of liquid waste will be controlled by the floor drains in the building. There will be no increases in liquid waste effl.uents to the environment due to operation of the System. The equipment will be designed to the requirements onclined in Nuclear Regulatory Commission Branch Technical Position ll-1.(Revision 1).

The final product (ash) from the Radwaste Reducation System will be processed through the solidification system into 55-gallon containers. In the event that the Radwaste Reduction System is not operating, for any reason, the waste will go directly to solidification. The solidification system will be remotely operated. It will be capable of processing any of the raw waste or the Radwaste Reduction System ash described above into a free-standing solid with no free water.

Under the present schedule, groundbreaking for the new building is to take place in February,1979. The system is expected to be operational by October, 1980.

Very truly yours, NIAGARA MOHAWK POWER CORPORATION h t. A d [ b Li Donald P. Dise Vice President-Engineering LMM/s=d -

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I. Background .

The Radwaste Reduction System for radwaste volume reduction has been des-

cribed in detail in the Licensing Topical Report.1 The installation at

Nine Mile Point Unit 1 will not vary significantly from the System

. described in this Licensing Topical Report.

As was stated in the Licerming Topical Report, the basic processes of

liquid calcination and combustible waste incineration which are used in

' the Radwaste Reduction System has been used in industrial plants for

• decades. Fluidized bed calcination of radioactive wastes was developed during the period 1952-1959 at the Idaho National Engineering Laboratory.

Use of calcination for liquid radwaste reduction was first de=enstrated in an engineering scale facility, the Waste Calcining Facility, at the Idaho Chemical Processing Plant in 1963.- The successful operation of the -

Waste Calcining Facility has demonstrated that liquid wastes can be routinely calcined into a granular free-flowing powder which can sub-L sequently be handled in a simplified manner. Since 1963, the Waste lt Calcining Facility has handled over 2.5 million gallons of radioactive i

aqueous wastes which have been calcined to approximately 42,500 cubic

, feet of solids.

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l Incineration of combustible radioactive wastes has been in use as a .

disposal technique since 1948 when a pilot plant incineratcr and offgas cleanup system were built at Mound Laboratory. Early systems were adaptations of standard refuse incinerators and did show that con-siderable volume. reduction in waste handling was possible.

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ThNRadwasteReductionSystemisbasedonadvancedfluidizedbedtechnology using an inert bed medium to incinerate and calcine with a single-chamber process vessel. The purpose is to reduce the volu=e of the radwaste o shipped offsite. Efficient volu=e reduction process depends upon

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, complete combustion and effective separation of gases and solids in the r effluent gas stream. This separation takes place in the offgas cleanup l system. The high heat capacity of the fluidized bed gives the high temperature stability and results in very efficient combustion. Tha air, which maintains the bed in its fluid state, provides an ample supply of oxygen for combustion. Some wastes such as sludges and slurries do not have sufficient caloric content to =aintain the bed at

'the desired temperature. In these cases, additional heat is provided by the combustion of supplemental fuel. The thermal inertia of the bed l ensures that the system is relatively insensitive to moderate ve-dations and caloric content of the feed. In the calcination mode, hea: . Med

• to drive off water as a vapor, leaving behind an incombustible re;';ae.

This incombustible residue is ground off the bed particles by the agitation of the bed and exits frem the process vessel to a dry cyclone. The calcination process is endothermic, and heat is supplied by the combustion of supple = ental fuel. The use of special inert bed material means that the bed does not have to be changed when switching from incineration to calcination.

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l

) 1. Topical Report, Radwaste Volume Reduction System, EI/NNI-77-7-P, l Newport News Industrial Corporation and Energy Incorporated, June 1077.

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l 11. System Description The systes consists of the process vessel, a dry cyclone, a product hopper, a wet scrubbing system and filtration system. Solids (ash) are

. removed as the gas exits from the process vessel cyclone. A product hopper collects the solids from the cyclone. Figure 1 shows the major

. components in a block flow diagram.

Process off-gas leaving the incinerator-calcinator vessel is cleaned in a mechanical dry cyclone, a wet scrubbing system and filtration system.

The wet scrubbing system is comprised of a spray quench tank, a high energy venturi scrubber followed by a wet cyclone, a condenser, and mist

, eliminator. Gaseous fission products (iodines) are removed by the scrub liquid and by an adsorber.in the filtration system. Particulate material is removed by the dry cyclone, wet scrub system, and high efficiency particulate absolute filters. Cleaned offgas is vented to the atmosphere

. (via the plant stack) while the product, a dry granular residue from the dry cyclone, is removed for solidification, storage and shipment. Scrub 1 liquid will be processed through the liquid waste system.

The system is designed to operate at a negative pressure with respect to its surroundings, thereby providing further assurance that no leakage of radioactive material will occur. Continuous air monitors are intended to monitor the room ai.r.

The high efficiency treatment of the offgas cleanup system minimizes the release of gaseous effluents to the at=osphere. In case a portion of the offgas cleanup system should fail to clean adequately, the Radwoate Reduction System has the capability of recirculating the offgas through the cleanup system instead of releasing it to the atmosphere. This a action is initiated by the radiation monitor in the exhaust stream.

There will be no liquid releases from the System directly to the environ-(,) ment. Scrub liquid goes to an internal hold-up tank before returning to

. the liquid radwaste system.

Appropriate instrumentation will be provided to (acect conditions that may result in excessive radiation levels within tre System. Controls designed to sense and activate an alarm upon the occurrence of a wide variety of off-normal operating conditions will be included. A part of the controls will be an annunciator panel, which will prnvide identification of the causes of an alarm. Corrective action will be taken either automatically or manually, depending on the potential seriousness of the

occurrence. Offgas from the system is routed to the main stack. The ,

stack monitoring system will =enitor these releases. In addition, a t separate system radioactivity monitor will be located in the offgas exhaust line to the plant stack. The incre= ental dose races, as shown -

in Table 1 for normal operation, are well below the limits set in Appendix I to 10CFR50. The radioactive effluents produced by the System during normal operations will be so small that their addition to other effluents currently discharged from Nine Mile Point will have no significant environ = ental i pact.

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. '1mm es11d grenuler rasidus, or product, of th3 Syste2 will b2 prekaged cad transportsd to a licanstd dispossi sito. In accordancs with Rigulatory Guide 1.21, provisions will be made to monitor and to limit the radiation from each package of solid waste. This will permit the operator to control radiation exposure to personnel and to meet the regulatory requirements of 10CFR71. -

III. Accident Analysis The System as installed at Nine Mile Point Unit 1, will be in compliance with Federal Regulations concerning protection of personnel against radiation and other technical and legal licensing requirements.

' The system design results in very low radiation levels. The individual cubicles formed by the concrete shield walls, and the operation of the System at less than atmospheric pressure, will assure that the operational, dose rate is below the levels required by 10CFR20 and are consistant with the original plant design criteria. The emissions from operation t

of the system result in concentrations and dose rates at the site boundary, which are well below the limiting valuer of 10CFR20 for unrestricted areas. ,

In this report two types of releases to the atmosphere are considered:

. normal releases from regular operations and abnor=al releases due to a

. transient event or an accident. Because of the high efficiency of the offgas cleanup system, nor=al releases are inconsequential. The normal release rates frem the system have been ecmputed, and are shown in Table 1 using the maximum activities and composition shown on Table 2 and the decontamination factors from Table 4-2 of the Licensing Topical Report.

The dose factors are from Regulatory Guide 1.109; a breathing rate of 20 cubic meters / day has been used. The annual dose contributions are all less than 0.001 millirem.

, Exposures from transient events and accidents have been discussed in s Section 4.3 of the Licensing Topical Report. No additional coverage of transients will be presented here. None of the transient events have i

consequences which are more severe than the maximum credible accident.

As in the Licensing Topical Report, the maxi =um credibla accident for the Nine Mile Point Unit 1 Radwaste Reduction System is the gross failure of the product container.

The doses presented for this accident are presented in Table 3. These doses are conservative since it was assumed that only 90 percent of the activity was retained by the building and ventilation system. The building housing of the Syste= is a seismic I structure and the building ventilation dischafges to the plant stack. In addition, the system will also be located in a cubicle within the radwaste building. If the product container were to catastrophically fail, much of the material -

would be retained inside the cubicle. The amount escaping the cubicle would be drawn into the ventilation system. The ventilation system will contain a high efficiency particulate absolute filter having a removal efficiency of 99.97 percent. Therefore, of the a=ount escaping the cubicle, approxicately 0.03 percent wculd escape the filter acd be discharged to the plant stack.

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l The ccptcity of th2 product centainst is equivalcat to thras 55-gallen drums (0.624 cubic meters), and it is conservatively calculated that 1710 curies is the maximum credible activity that can be expected to accumulate in the product container. This is based on the maximum specific activity for filter sludge shipped reported for any six months (68.5 curies / cubic meter). This occurred in the second half of 1975.

This has been multiplied by a factor of 2 to allow for variations within this six-month period. Thus, it is assumed that enough feed is available at 137 curies / cubic meter to fill up the product container. The maxi =us

. volume reduction factor envisioned for waste other than dry, combustible solids is 20

1. The 1710 curies is over 2/3 of the annual expected activity for resin / sludge. It is extremely unlikely that such a large portion of the activity in a year's vaste would accumulate in such a small volume. The composition of the 1710 curies is taken to be that given in the resin / sludge column of Table 2.

Despite the above, it is conservatively assumed that 10 percent of the

-s granular ash (171 curies) in the product container escapes from the t

• building containing the System and remains airborne long enough to reach the site boundary. The doses due to this release are shown in Table 3. The site boundary closest to Nine Mile Point Unit 1 is 1,500 meters in the southwest sector. The dilution factor, X/Q, from Regulatory Guide 1.3 for an elevated (100 =eter) release and fumigation conditions are assumed. The material was assumed to be released in the first four (4) hours. These assumptions are from the latest Regulatory Guides and are therefore different from the assu=ptions used in the

. Nine Mile Point Unit 1 Final Safety Analysis Report. The dose factors have been taken from Regulatory Guide 1.109, and the breathing rate was 20 cubic meters / day. The maxi =ca dose uas found to be 534 mre= to the lung.

- IV. Associated Waste Handling Eculp=ent l

! A anlidification system will be added to solidify wastes processed by the System and the existing radwaste facility. It will consist of dry cement storage and handling equip =ent, 55-gallon barrel filling, miring equipment, and settling / decant tanks. This equipment will be of the same basic design as that at Dresden 2 and 3.

An overhead crane will be installed for transporting barrels from the l mixing station to storage and for loading them onto trucks for shipment .

and offsite burial?

Existing wastes such as filter sludges, resins and evaporator bottoms -

will either be processed by the system as described earlier or will be solidified directly. These wastes, if solidified directly, will be settled and decanted to the desired concentration. They will then be mixed with a prc=easured a= cunt of ec=ent in a 33-sallon barrel. A test will be conducted after solidificctica :o ensure that no free water is present.

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The 55-gallon barrels will then be transported by the crane to the.

storage area (s). A barrel grab mechanism equipped with TV cameras ~'11

• be used to pick up and locate the barrels in the storage areas, A er, the storage areas will be inaccessible to personnel and the entirn operation will be remotely operated. Adequate shielding will ensure that radiation levels in normal plant access areas are consistenc vich the existing plant design. In addition, the roof over the barrel storage areas will be two (2) feet thick to ensure acceptable radiation levels outside the building.

The crane described above will have access from the barrel storage area (s) to the cruck loading bay. Barrels handled by the crane will

be located by position in the storage area, picked up and placed in a cask on a truck. These operations will be remotely controlled.

Controls for the system as well as alarms and monitoring equipment

( important for the operation of the system will be located in a control e room in the new building. Each barrel in storage will have a number i assigned corresponding to its location. Other information on each

! barrel will also be recorded on a board in the control room such as

radiation level, weight and date placed in storage.

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TABLE 1 -:

1 ADDITIONAL EMISSION RATES, BOUNDARY CONCENTRATIONS, AND DOSE RATES DUE TO OPERATION OF Tile RADWASTE REDUCTION SYSTEM Maximum

aximum , Decontamination Release .

. Concentration Boundary Feed Hate Dose Rates Factor Rate Limit Concentration Thyroid Lung (C1/ year) Tota.

(ci/ year) (pci/m3) (pcJ/m 3) (nrem/yr)

NA-24 4 x 10 4 -4 15 3.8 x 10 5000 6.7 x 10 ~7 8.3 x 10'9 8.3 x 10~9 8.3 Hn-54 4 -3 o 125 4 x 10 3.1 x 10 1000 5.5 x 10 -6 -6 0.0 7.0 x 10 3.2 3 Co-60 915 4 x 10 4 2.3 x 10

-2 300 4.0 x 10 -5 0.0 2.2 x 10 -0 5.5 Sr-89 4 ~0 10 4 x 10 2.5 x 10 300 4.4 x 10 ~7 5.6 x 10 ~7 0.0 3.5 4

I-131 50 1 x 10 5.0 x 10 -3 100 8.8 x 1

-6 9.6 x 10-5 6.0 1.7 0 -2 Cs-134 1225 4 x 10 3.06 x 10 -5 400 5.4 x 10 0.0 4.8 x 10 ~0 3.6 4

Cs-137 2160 4 x 10 5.4 x 10 -2 500 9.5 x 10

-5 0.0 6.6 x 10 -6 3,7 d

TOTAL 4500 1.16 x 10'~1 -

2.1 x 10

~4 -5 ~4 9.5 x 10 2.4 c 10 7.4 o

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' PROJECTED ACTIVITIES IN THE LIQUID AND RESIN / SLUDGE FEED ~

TO THE RADWASTE REDUCTION SYSTEM FOR NINE MILE POINT UNIT ONE -

f Liquid Resiti/ Sludge Expected Maximum Expected Maximum

. (percent) (Ci/yr) (Ci/yr) (percent) (Ci/yr) (Ci/yr) e ,

Na-24 1.5 9 15 .

Mn-54 2 12 20 ,

3 75 105 .

, Co-60 11 66 110 23 575 805 ,  ;

Sr-89

. 1 6 10 -

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I-131 1.5 9 -

15 1 25 35 Cs-134 35 210 350 25 625 875

. Cs-137 48 '288 480 .

48 ' 1200 1680 Total 60 1000 2500 3500 d

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1 thole 3 DOSESATTHESITEBOUNDARYbuETOTHEMAXIMUMCREDIBLEACCIDENT _

FOR THE NINE MILE P,0 INT UNIT !1 RADWASTE REDUCTION SYSTEM 10% of the Ash Released

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OrganDose(mrem)

Nuclide Bone Liver Thyroid Kidney Lung Total Body Mn- 54 0.0 0.4 0.0 0.1 15.3 0.1 Co- 60 0.0 1.0 0.0 0.0 496.5 I-131 1.2 0.1 . 0.1 43.2 0.2 0.0 0.1 Cs-134 33.5 76.5 0.0 26.1 8.7 65.7 Cs-137 82.8 107.7 0.0 38.7 13.2 74.4 TOTAL 116.4 185.7 43.2 65.1 533.7' 141.5

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Radwaste Reduction System Block F. low Diagram- I j

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Cases and ***

Water vapor Quench v Scrubber s Wet '

Cond* ' "" -

Tank Cyclone Eliminator

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Cases Scrub Liquid Liquids Dey Scrub ,

- Cyclono Liquid '

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Tank 51sh Process Efficiency Solida #***#*"I'"*

Vessel Filter sr '

f Product .

To Liquid Container Wasta Processing , ,

W:stes Iodine Adsorber h

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• Solidiffcation '

High

. Efficiency Filter i

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To Plant Stock /