ML17340A348

Forwards Responses to Questions 2,3 & 4 of NRC 801021 Request for Addl Info Re Disposal Alternatives.Response to Question 1 Will Be Submitted in Near Future

ML17340A348
Person / Time
Site:	Turkey Point
Issue date:	10/31/1980
From:	Robert E. Uhrig FLORIDA POWER & LIGHT CO.
To:	Varga S Office of Nuclear Reactor Regulation
References
L-80-364, NUDOCS 8011050436
Download: ML17340A348 (13)

Text

REGUL'A'TORY INFORMATION DISTRIBUTION SYSTEM (RIDS)

ACCESSION NBR:8011050036 DOC ~ DATE: 80/10/31 NOT'ARIZED! NO, DOCKET FACIL:50 BYNAME 250 Tur key Point Planti, Unit 3i F'lorida Power and Light C",

50 251 Turkey Point Pl anti Uni t 0i Florida Power and Light C f50~0251 AUTH AUTHOR AFF'IL'IATION UHRIGi R ~ 'E ~ F~lorida Power 8 Light Co ~ ,

RECIP,NAME REC'IPIENT AFFILIATION VARGAiS ~ A ~ . Operating Reactors Br anch 1

SUBJECT:

Forwards responses to Questions 2'i3 L 0 of NRC 801021 request for addi'nfo re disposal alternati.vest Response to Question 1 wil,l be submitted in near futures DISTRIBUTION CODE ~ A00 1S, COPIES RECEIVED! L~TR Qof ENCL SIZE TITLE: Gener aIl Distribution for af ter Issuance Operating License NOTES'RECIPIENT COPIES RECIPIENT COPIES ID CODK/NA'ME LiTTR ENCL ID COPE/NAME , LTTR ENCL.

ACTION! VARGAiS ~ 00 13 13 INTERNALS D/DIRi HUM FAC08 1 1 ILE 06 2 2 NRC PDR 02 1 1 OELD 11 1 0 OR ASSESS BR 10 1 0 01 1 -

1 EXTERNAL: ACRS 09 16 16 LPDR 03 1 1 NSIC 05 1 1 OV 8 t980 TOTAL NUMBER OF COP'IES REQUIRED: LTTR 38,,E/CL, 36

P.O. BOX S29100 MIAMI,F L 33152 RKBVEIM)I~I, 8U~~(,gg C SshNCEMSNi FLORIDA POWER & LIGHT COMPANY October 31, 1980 L-80-364 US NRC CI'" !;;,;",U II1'I "ERYICES; ijQH Office of Nuclear Reactor Regulation Attention: Mr. Steven A. Varga, Chief Operating Reactors Branch 5'1 Division of Licensing U. S. Nuclear Regulatory Commission Washington, D. C. 20555

Dear Mr. Varga:

Re: Turkey Point Units 3 8 4 Docket Nos. 50-250 8 50-251 Steam Generator Re air Enclosed you will find Florida Power 5 Light Company's responses to guestions 2, 3, and 4 of the Request for Additional Information on Disposal Alternatives transmitted with your letter of October 21, 1980. The response to guestion 1 is being prepared and will be submitted in the very near future.

Please advise us if you require further information.

Very tr yours, Robert E. Uhrig Vice President Advanced Systems & Technology REU/LFR/ah Enclosures cc: Norman A. Coll, Esquire J. P. O'Reilly, Region II oe I Harold F. Reis, Esquire Mark P. Oncavage 5 Neil Chonin Henry H. Harnage Bert L. Saunders PEOPLE... SERVING PEOPLE

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EnÃusure RE UEST'OR ADDITIONAL INFORMATION DISPOSAL'LTERNATIVES Question

l. Describe the hurricane resisting properties of the storage building for the steam generator lower proposed ower assemblie .

Answer to be provided in the near future question

2. Describe the procedures and methods used to assure that the inside of the steam generators remain dry while in storage.

Answer Prior to decontamination and cutting, the steam generators will be drained of all primary side water. Because of the geometry of the tube bundle (i.e.,

gravity drained) there will be no need for special drying provisions.

The secondary side will also be drained. However, some residual secondary side water may remain since it is below the level of the blowdown piping.

Additionally, some plugged tubes may also retain some secondary side water.

Ilowever, since this is secondary side water, it is relatively clean, and need not be compl'etely removed for radiological purposes. Also, results from an oxygen depletion study show that this secondary side water would not be sufficient to support through wall corrosion of the stored steam generators. Therefore, again, no special drying provisions are needed.

guestion

3. Describe the transportation impacts of'he shipment of generator lower assemblies, including potential the'team accidents, along the route.

Answer See Attachment.

guestion Describe the method of "sealing" the steam generator lower assemblies. In particular, the thickness, strength, etc.

of the caps for the open ends of the steam generators and pipe cuts, and the geometry and dimensions of the weld joints.

Answer The various openings in the steam generators will be closed either by steel plates or by steel bar stock as follows:

a) The large channel head and transition cone openings will have steel plates, three inches thick, placed over them and will be welded closed by a 1$ inch fillet weld.

b) The small nozzle connections '(i.e., instrument taps,, drains, and blowdown nozzles, all 2 inches and smaller) will have bar stock inserted into the openings and will be welded closed'y a lg inch fillet weld. The bar stock wil1 be a minimum of two inches thick.

c) The handhole openings will have steel inserts welded with a 1$

inch fillet weld to the inside of the opening. The handhole cover plates will also be put back into place over the handholes.

These inserts wi11 be a minimum of two inches thick.

Evaluation of Offsite Shipment oheEnvironmental Turke Point'te'am Gen'eiat'or Lower As'semblies

l. 0 Xntroducti'on An alternative for disposal of the Turkey Point, Units 3 and 4 steam geneiator lower assemblies may be shipment to a nuclear waste burial ground at, Barnwell, S.C. The following evaluation presents a general description, of the'lans for and of the estimated environmental impact from offsite ship-ment. Further relevant details are contained in the Steam Generator Repair Report.

2.0 General Descri tion of Offsite Shipment Before the lower assemblies are removed from the con-tainment buildings and shipped offsite, each will abc completely

.pealed by welding to prevent the release of radioactive material during shipment.

After removal from the containment, the first lower assem-bly from each unit will be lifted by a gantry tower and crane and loaded into the lower half of a carbon steel shipping cask which, will be attached to a transporter. The lower assembly will then be secured and the upper half of the shipping cask will be bolted to the lower half, completely encasing the lower assembly. The transporter will then move to the barge slip at Turkey Point and will be driven onto a barge and secured.

The barge will then, proceed, through Biscayne Bay to the Atlantic Ocean, along the'-'coastline-;,and up the 'Savannah Pw<<

vei. The 'transporter will disembark. from the barge at a barge slip in South Carolina.

At the burial site, the upper half of the shipping cask

.wiU. be remov d, and the lower assembly will be lifted and plyc'ed in a burial trench.'he" transporter will then retrace its steps, be loaded on the barge, and return to Turkey Point for shipment of another lower assembly.,

Hhile the first lower assembly of each unit is being trans-

'ported to the burial site, the second and third lower assemblies will be removed from the containment building and temporarily stored on the laydown area to await transportation. The second lower assembly will rest at the laydown area for approximately th'ree weeks before loading, and the third assembly will rest ap-proximately six weeks before loading. The process described above will be repeated until each of the 3,ower assemblies reaches its destination at the burial site.

3.0 Environmental 1m acts of Offsite Shi ment 3.1 Non-Radiolo ical Xm 'acts.

The non-radiological environmental impacts from offsite shipment are negligible. The pollution emitted by the. trans-porter and the barge is an inconsequential addition to the pol-lution emitted by ground and water transportation normally travelling on the same route. Similarly,. the commitment of

resources for offsite shipment (such as fuel for transporta-tion and land for burial of the'team generator lower assem-blies) is minimal..and insignificant in comparison to national and'regional commitments of the same resources. In short, offsite shipment will not produce any significant non-radio-logical impa'ct.

3.2 'Radiolo ical Imp'actfrom'outine'h'i ment Before. removal from the containment building, the ex-terior surface of the lower, assemblies vill be decontaminated as necessary to reduce the level of removable contamination to within an insigni'ficant 2200 dpm/100 cm . Additionally, since the lower assemblies will be sealed using 2-3 inch steel plates and inserts and 1 1/2 inch fillet welds prior to removal

'from the containment buildings, no radioactive effluents from within the lower assemblies will be emitted'uring shipment.

Consequently, only direct and scattered radiation which may be emitted from within the sealed lower assemblies need be considered.

Approximately 250 curies of radioactive isotopes are con-tained within, each lower assembly as a layer o.F Die<~~'">c.co~~o-sion products which tenaciously adheres to the primary side surfaces of the lower assembly. The radioisotopes are en-cased within the two to three inch thick steel shell of the lower assembly, which in turn is encased within the 2 1/2 2 3/4 inch thick steel shipping cask. Dose rates from this activity will be

limited to .less than 10 mrem/hr six feet'rom the .cask:

surface. Radiation 'surveys will be taken periodically before, during,'nd after transportation to confirm that radiation le-vels are within acceptable limits.

Cumulative doses to the public from offsite shipment have been calculated. Based upon 600 miles'f barge 'trans-portation and 40 miles of road transportation per shipment

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. of one lower. assembly, and based upon the conservative assump-tion of a dose rate of 10 mrem/hr at 10 feet from the shipping cask surface, the estimated dose to the public from temporary on-site storage, loading, offloading, and transportation of all six lower assemblies has been determined to be less than 0.1 man-rem.

Occupational exposures associated with offsite shipment have also been evaluated. It is estimated. that shipment of all six steam generator lower assemblies, including removal from the containment building, temporary onsite storage, load-ing, offloading, and transportation, would result in approxi-mately 53-56 man-rem to workers. This is roughly equivalent to the estimated occupational exposure which would be incurred from onsite storage of the lower assemblies, and considerably less than other alternatives.

Exposures to 'individual workers will be maintained within the limits specified in 10 C.P.R. Part 20. Additionally, 'a train-ing program will -be conducted for all personnel participating in shipment activities whose duties will require them to enter ra-diation areas or to handle radioactive material. This training

program, as well as other administrative contains, will help en-sure that occupational exposures will be maintained, as low as reasonably achievable.

3.3 Radiolo ical Xm act's 'from Pos'tulate'd'occi'dents

3. 3. 1 Xntxoduction Shipment of new steam generators and other heavy eguip-ment by barge is not a novel or unusual task. Numerous steam generators have previously been shipped by 'barge, including six original and six replacement steam generators for both Turkey Point and Virginia Electric and Power Company's Surzy Plant.. Additionally, one contaminated steam generatox lower assembly has been shipped by barge from Surry, Virginia, through the Panama Canal, to Hanford, ~rlashington. Experience indicates that the occurxen'ce of an accident during shipment's extremely unlikely. The most probable accidents axe analyzed below.

3.3.2 Drop of a Steam Generator Lower Assembly during Loading or Offloadin During loading and offloading of the shipping cask, it will be necessary to lift the lower assemblies a maximum of twelve feet off the ground. Xt has been calculated that the probab'lity of dropping a lowex assembly during such a lift is of the order of 10 . Thus, it can be seen that the occurrence of a drop accident is extremely improbable. Nevertheless, x.f it is assumed that a lower assembly does drop during lifting, it is not expected that it vill be breached.

.3.3.3 Acc'idents'u'r'ing Ground Tran's rt'ation Various accidents are theoretically possible 'during ground tranSportation, including collapse of the road surface,'

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brake failure, tire blowout, tipping while negotiating a 'curve, and collision. Accidents such as tire blowouts or the .collapse of the road, followed by tipping of the transporter, would not impart sufficient mechanical shock to breach the lower assem-blies. During turns, the transporter cannot reach a sufficient

..speed to induce overturning since turning is manually controlled by an operator walking alongside the transporter. Moreover, it is extremely unlikely that the transporter would reach excessive speed due to a total brake failure, since the transporter and its tractor have independent braking systems, each of which is adequate to stop both the transporter and the tractor. Finally, the're are no. bridges off which the transporter could fall, and the roads and crossroads over which the transporter will travel will be blocked to other traffic in order to prevent potential collisions. Thus, the worst case accident (that producing the greatest mechanical shock to the steam generator lower assembly) would be a brake failure on an incline followed by an impact of the shipping cask and lower assembly onto an unyielding. surface. In-such circumstances, the .lower assembly inside of the shipping c sk is Root:-epected*: tO-;be. bPevehed.;.,jo'-no radioactive materials -'wo'Uld'e released to the environment.

3. 3. 4 Acciden'ts durin' Mat'er Tran's rtati;on 1

Two.hypothetical accidents .wet'e. considered ..during, barge.-

transportation of ' lower assembly'. The:first ~simulated. acci-dent is a ship collision withthe barge. The probability of a collision severe enough to sink the barge is of the order of l0 per barge mile, which is extremely remote. Moreover, it is calculated that the impact of such a broadside collision is opt "=

expected'ito.breach the shipping cask or lower assembly.

The second postulated'ccident is the sinking. of the assembly,'heeither by a collision or sh'pping cask and the lower 'I by other means. Such a hypothetical sinking could occur, in three places: Biscayne Bay, the Atlantic Ocean, or the Savannah River. It is calculateQ that sinking of the shipping cask and the lower. assembly in Biscayne Bay or the Savannah River might breach the shipping cask, but the lower assembly is,not expected to,be prjgphqd>and no activity would be releaseQ. If the shipping cask and the lower assembly sink in the Atlantic Ocean, tne lower assembly could be breacheQ. it If is conservatively as-sumed. that 100 percent, of the activity within the lower assembly is immeQiately released to the ocean, the resulting dose to the maximum exposed individual via the aouatic food pathway would be less than .05 rem whole body and

.5 rem to the gastrointestinal tract. Doses to the average individual l

would be considerably less.

3.3.5 Fires Accidents involving fires would have lesser consequences than those considered above. The 'melting point. of the lower assemblies is considerably highex'han that of the'ost severe

'fire which could be .reasonably encountexed during shipment, and the heat would actually cause the radioisotope layer to be' come'ore'dherent to the inside of the lower'ssemblies. Since the increase in internal pressure developed by such a fire would'ot'ause the lower assemblies to rupture,.'heie would, be no 'release of radioactive materials due 'to fire.

3.3.6 Accidents. durin Tem 'orar Onside'tora e The second anQ third lower assemblies which 'will be re-moved. from each unit will be temporarily stored on the Turkey Point laydown area prior to transportation to the burial site.

The laydown area is not frequented by vehicles or within falling distances of nearby structures or equipment. Additionally, this storage will not occur Quring the hurricane season. Thus, no accident scenario which could breach the lower assemblies during.

temporary onsite storage is considered credible.

3.3.7 Prevention and Miti ation of Accidents Several procedures will be utilized to prevent the oc-currence of accidents and to mitigate. the consequences of those accidents which do occur.

The gantry anQ cranes will be inspected and tested be-fore the lower. assemblies are loaded or offloadeQ.

The roads along the transporter route have been selected to minimize grades, sharp curves, and travel thxough populated areas, and r'oads that have been inspected will be xeinspected:

before shipment to .ensure their. ability to withstand the ex-pected load. Moreover, administrative controls will be placed

...upon the speed of the transporter to reduce the probability of an accident. Finally, an escort will be provided for the transporter to -protect the transporter against traffic.

Xf the shipping cask and the lower assembly sink in the Savannah River or Biscayne Bay, they will be recovered. Such a recovery could be easily accomplished given the relatively shallow depth of these bodies of water.

4.0 Conclusions

'The non-radiological impacts associated .with offsite ship-ment are negligible. The primary radiological impacts resulting from routine offsite shipment are approximately 53-56 man-rem occupational exposure and O.l man-rem. public exposure. These exposures are roughly equivalent to those estimated for onsite storage.

The probability'f an occurrence of an accident is extremely remote. Moreover, most of the postulated accidents will not re-sult in breach of the lower assemblies'r in a release of any radioactivity to the environment. Even if a breach should occur, the consequences would not be significant.