ML20010B444

Forwards Suppl 1 to Revision 1 to Joseph Oat Corp Rept, Licensing Rept on High Density Spent Fuel Racks for Quad Cities,Units 1 & 2. Related Correspondence

ML20010B444
Person / Time
Site:	Quad Cities
Issue date:	08/10/1981
From:	Fitzgibbons R ISHAM, LINCOLN & BEALE
To:	Atomic Safety and Licensing Board Panel
References
ISSUANCES-SP, NUDOCS 8108140476
Download: ML20010B444 (1)

Text

, NCB ithLATED COIULESPONDE ISHAM, LINCOLN & BEALE COUNSELORS AT LAW ONE FIRST NATION AL PLAZA FORTY SECOND FLOOR

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m ATOMIC SAFETY AND LICENSING BOARD

• In the matter of )

) Docket Mos. 50-254-SP COMMONWEALTH EDISON COMPANY ) 50-265-SP (Quad Cities Station, ) (Spent Fuel Pool Modification)

Units 2 and 3) )

Dear Administrative Judges:

Please find enclosed a new section to the

' report prepared by Joseph Oat Corporation for Commonwealth Edison Company entitled " Licensing Report on High Density Spent Fuel Racks for Quad Cities Units 1 and 2." This new section incorporates into this report Commonwealth Edison's responses to technical questions received from the NRC Staff. As with all the earlier sections there will be forthcoming revisions.

Sincerely, l

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R.y q.

! Robert G. Fitzgibbons, Jr.

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cc: Service List / Enc.

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Commonwealth Edison On: First N tional Prza. Chicago. Ilhnois gpTJW CORRESPOEDgg 7, g Address Reply to: Post Office Box 767 Chicago. Ilknois 60690 d. N ,

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'N' July 24, 1981 $: .1 H AUG 121981 r. L~-- '

B c m m :th n u e rf 3 L:' .. . ; '. Ordc3 Mr. Harola R. Denton, Director t;; n Office of Nuclear Reactor Regulation k, U.S. Nuclear Regulatory Commission a3 as Washington, DC 20555

Subject:

Quaa Cities Station Units 1 and 2 Transmittal of Supplement 1 to Refision 1 of the Licensing Report on High Density Fuel Racks NRC Docket Nos. 50-254/265 Reference (a): T. A. Ippolito letter to J. S. Abel dated May 15, 1981.

(b): T. A. Ippolito letter to J. S. Abel dateo May 18, 1981.

(c): T. A. Ippolito letter to J. S. Abel dated May 19, 1981.

(d): T. A. Ippolito letter to J. S. ADel

(" /

dataa June 16, 1981.

Dear Mr. Denton:

Enclosed is Supplement I to Revision 1 of the report prepared b. Joseph Oat Corporation for Commonwealth Edison entitled

" Licensing Report on High Density Spent Fuel Racks for Quad Cities Units 1 and 2". This supplement provides responses to a portion of the questions provided in References (a), (b), (c) and (d). The responses are provideo as a new Section 12 to the subject report.

Section 12 will be updated in the future to reflect aaditional responses as they are prepared.

Please adoress any questions you may have concerning this matter to this office.

One (1) signed original and thirty-nine (39) copies of this transmittal are provideo for your use.

Very truly yours,

.h~m ((/am t Thomas [. Rausch Nuclear Licensing Administrator Boiling Water Reactors m

, Enclosure cc: Region III Inspector - Quad Cities im 2331N

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SUPPLDENT NO.1 TO REVISION NO.1 O 12. RESPONSES TO NRC OUESTIONS Given below are NRC questions concerning the Licensing Report on High-Density Spent Fuel Racks for Quad Cities Units 1 and 2. They are listed by date of transmittal. Also given below are reponses to those questions or the word "Later" indicating that the response will be communicated at a later date.

12.1 Questions from T. A. Ippolito to J. S. Abel transmitted on May 15, 1981 12.1.1 Question:

As a result of replacing the fuel pool racks, there is an appreciable increase in the applied load to the fuel pool concrete floor. Indicate the method and l the code used in the analysis of the concrete fuel pool slab.

Response Later ,

12.1.2 Question:

Provide the floor response spectra or the time history used in the analysis of the spent fuel racks and state the source of this information.

Response: Later

() 12.1.3 Question:

Indicate the damping value used in the analysis of spent fuel racks and state whether this value conforms with Regulatory Guide 1.61. .

Response: Later 12.1.4 Question:

l Indicate whether material, fabrication, installation, and quality control l

I conform with the ASME code, subsection NF.

l Response Yes, material, fabrication, inspection and quality control conforms with ASME code, Subsection NF.

12.1.5 Question:

Indicate if there is any possibility that the shipping cask may drop onto the fuel pool liner or on to the fuel pool racks and what design considerations are given to the fuel pool liner and racks.

Response: Later 12.1.6 Question:

Provide the names of the codes and standards used in the fuel pool liner de-(} sign.

Response: Later 12-1

. _ . _ . . . . _ . . . _. _ _ _ _ _ ., . - , , _ , _ - . - _ _ , - - ~ _ - - - _.. _ .

12.1.7 Question:

With regard to the fuel assembly drop on the top of the rack, provide the following:

a. Detailed description of the method used to satisfy the eccept-ance criteria for dropped fuel accident I and II.

b. Comparison between drops in the tilted position, straight drop and on the corner of the rack,

c. Indicate whether other modes of failure of the racks exist beside crushing.

Responses Later 12.1.8 Question:

Indicate in detail the methodology used to demonstrate the leaktight intog rity of the fuel pool liner. when subjected to either the postulated fuel asseitbly drop or the cask drop over the spent fuel pool liner. The heavy drop should be analyzed for the tilted position and straight drop.

Response: Later 12.1.9 Question:

Indicate whether the proposed fuel storage pool modifications conform with the staff position on " Fuel Pool Storage and Handling Application", dated April, 1978, including revisions dated January, 1979. If any deviations exist, identify and justify these deviations.

Response: Yes, the guidance is followed, with the exception of the Technical Specification for maxisum enrichment. This is because of the variety of enrichments in the fuel and the existance of the subcriticality specification of k,gg less than or equal to 0.95.

12.1.10 Question:

The seismic analysis as presented in the submittal is not clear. Indicate in detail how all the seismic models and parameters (Figare 6.1, 6.3, 6.4, 6.5, 6.6, 6.7 and 6.8, the friction forces and floor response spectra) fit together to predict-the seismic stresses. Indicate the interrelation ship among the models.

Response: See Revision 1 to Chapter 6, Seismic Analyses Description, submit-ted . to the NRC by letter from T. J. Rausch to H. R. Denton on June 24, 1981.

12.1.11 Question:

Because different type modules were used in the proposed modification with different sizes and weights, indicate which type was used in the seismic and sliding analysis.- Indicate also how other types were qualified for the postulated loadings.

Response: Later 12-2

12.2 Questions from T. A. Ippolito to J. S. Abel transmitted on May 18, 1981 12.2.1 Question:

When Section 5.1, Heat Generation Calculations, is provided, include the following information:

a. Indicate the minimum elapsed time between shutdown and when the dis-charged fuel is in the spent pool for all anticipated fuel discharge cycles.

Reponse: Later

b. For Units 1 and 2 spent fuel pools, indicate the number of fuel assemb lies and their respective decay times of all fuel that will be in the pools when reracking occurs.

Response See Revision 1 of Licensing Report submitted to the NRC by letter from T. J. Rausch to H. R. Denton on June 24, 1981,

c. It is noted in the FSAR that portions of the RHR system may be used to augment the spent fuel pool cooling system by inserting spool pieces in the spent fuel pool cooling lines shown in Figure 10.2.1. In this regard, indicate the length of time required to install these spool pieces and describe the capability of the RHR system to remove the heat from the spent fuel pool over a range of pool temperatures and with and without the spent fuel pool cooling system in operation.

Response Later

d. For Units 1 and 2 indicate the length, width and depth of the spent fuel pools and the minimum volume of water in each when all storage racko are filled with fuel assemblies.

Response: Later

e. Figure 2.1 and 2.2 of the March 26, 1981 submittal shows that the down-comer region, i.e., space between the racks and walls of the pool, is quite small. Further, the vertical dimension of the water plenum formed by the base plate of storage racks and the pool bottom is 6-1/2 inches.

Assuming the maximum heat load is adversely located in the storage racks demonstrate that sufficient circulation will occur to preclude nucleate boiling.

Responses Later 12.2.2 Question:

Assuming the reactor is operating at power when it becomes necessary to utilize the RdR system to cool the spent fuel pool, describe and discuss the steps that must be taken and the elapsed time before the RHR system can be placed in the fuel pool cooling mode of operation.

Response: Using the Residual Heat Removal (RHR) System for fuel pool cooling will render one of the two loops (two pumps and one heat exchanger) unavailable for use in any of the safety functions (LPCI or containment cooling). Quad Cities Technical Specifications allow 12-3

LPCI and one loop of containment cooling to be inoperable during i reactor operation - as long as 1) the other loop of containment-cooling is available, both core spray systems are operable, and ,

both diesel generators are operable, ant' 2) the loop used for fuel pool cooling is returned to normal within seven days, or the reactor

, shall be shut down.

once it has been determined that supplemental fuel pool cooling i using RHR is necessary, the RHR/LPCI Mode Outage, %eport Surveil-lance would be performed, and crews would be di', patched to install the two spool pieces which join the fuel pool c".'".ing system to RRR.

i When this has been accomplished, the valving rperations may begin. l

, This involves the closing of several motor-or deated valves, racking l out the breaker on another motor-oper ated valve, and the opening of l two manual valves near the fuel pool cooling heat exchangers. Next, the RHR Shutdown Cooling Mode suction header must be filled and vented and the RER system vented. Finally, the RER service water system is started and an RHR pump is started to commence fuel pool cooling. The total elapsed time would be approximately three hours ,

if two mainte nance crews were available (one for each spool piece) -

or four hours if a single crew installed both spool pieces. At i times when no maintenance crew is on site, an additional one to two j hours would be required to assemble the necessary personnel.

12.2.3 Question:

For both Units 1 and 2 spent fuel pool reracking operations, provide the i I . following additional information l

a. Assuming a load drop, describe and discuss, with the aid of drawings, the travel paths of the new and existing storage racks with respect -to plant .

aquipment that may be needed to attain a cold safe shutdown or to  !

mitigate the consequences of an accident.

i' Response Diagrams will be prepared before moving racks based upon results of l NUREG-0612 studies.

b. Provide the weights of the racks. Describe and demonstrate the ade quacy M the lif ting rig attachment points, on the new and old racks, to withstand the maximum forces that will be experienced during the load

, handling operations.

i Response: The weight of the racks is contained in the Revision 1 Licensing Report submitted to the NRC on June 24, 1981 by letter from T. J.

, Rausch to H. R. Denton. Lifting rig requirements are not yet defined and will be submitted 1 ster.

c. With the aid of a drawing, describe the lifting rigs that will be employed in handling the racks and demonstrate tha,1r adequacp Response Later

d. Assuming stored spent fuel is in the pool when the storage racks are being removed or installed, deme'astrate that-the stored spent fuel is not -

4 within the area of influence of dropped racks should one or more of legs of the lifting rig fails.

12-4

Response: Later

e. FSAR Figures 12.1.1 and 12.1.2 shows a transfer ca 'al joining Unit 1 pool with Unit 2 pool. Assuming a significant number of loads are transferred between the two pools, describe the merits of providing additional protection in the form of a cover over those storage racks directly under this frequently travelled path.

Response: The assumption that a significant number of loads will be trans-ferred between the pools is incorrect. Both pools are nearly full which precludes significant transfers of fuel. With regard to adding a cover, this cover would only add another heavy object consideration in additon to thermal cooling concerns.

f. For both Units 1 and 2, with the aid of drawings, sequentially describe the movement of the stored spent fuel assemblies and storage racks in order to reduce the possiblity of fuel damage in the event of a load drop during the reracking operations.

Responses All wo-k will be planned in advance and detailed procedures de-veloped to reduce the possibility of load drops and resultant fuel damage.

g. Considering the limited space between the storage racks and the pool walls, describe the travel paths and laydown area for various pool gates.

Demonstrate that the consequences of a dropped gate are accept able or that one can reasonably assume that dropping of the gates is very unlikely.

' O Response: Later

h. Using Figure 3.7, describe and discuss the ability of the high density storage racks to protect the stored spent fuel assemblies from damage following a load drop.

Response: Later

i. In regard to the potential for damage to stored spent fuel resulting from 4

light load drops (i.e., one fuel assembly and its associated handling tool when dropped from its maximum carrying height), it was assumed that all lesser loads that are h;sndled above stored spent fuel would cause less damage if dropped. Verify that this assumption was correct, e.g.,

indicate that all lesser loads when dropped from their maximum elevation would impart less kinetic energy upon impact with the tops of the fuel assemblies and or storage racks.

Response: Later 12.2.4 Question:

Since Figure 2.2 shows that essentially all available space in Unit 2 pool will be occupied by storage racks, therefore, all Unit 2 stored spent fuel

,A must be moved to Unit 1 pool via the transfer canal before it can be loaded into the shielded shipping cask. Describe and discuss what measures will be taken to reduce the possibility of fuel assembly damage resulting from the additional fuel handling operations.

12-5

Response: It will not be necessary to move all Unit 2 fuel thru the Unit 1 pool when it becomes possible to ship fuel. The racks in the Unit 2  !

b cask handling area will not be installed unless required. If they were installed, they could be removed to facilitate the use of a I

cask later. In addition, all fuel movements will be accomplished by approved procedures to reduce the possibility of fuel assembly ,

damage. )

12.2.5 Question:

For both Unit 1 and Unit 2 storage pools, starting with the total decay heat I load that will exist in each pool following the reracking operations, provide the following information:

a. a plot of the pool's maximum anticipated total decay heat load result ing from normal discharges versus time until each pool has reached its storage capacity.

Response: Later

b. Verify that all decay heat calculations have been made in accordance with ASB technical position 9-2.

Responsa: Later

c. a plot of the pool's water temperature versus time for ecch discharge l where the total decay heat exceeds the capacity of the spent fuel pool l q cooling system. Indicate what cooling systems are in operation and their

! V respective capacities.

Response: Later

( d. a plot of maximum decay heat load in each pool, assuming a full core discharge at each of the normally scheduled refueling periods.

Response: Later

e. a plot of the pool's water temperature versus time following each full l

core discharge assumed in Item d above. Indicate what cooling systems are in operation and their respective capacities.

Responses Later

f. Assuming the maximum heat load exists in Unit 1 and Unit 2 pools when all external cooling was lost, indicate the time interval before boil ing occurs and the boil off rate.

Response: Later

g. Describe and discuss the sources of makeup water, the quantity avail able, their respective makeup rates and the steps that must be carried out and the elapsed time before the makeup water will be available at the pools.

Response Later 12-6

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12.2.6 Question:

Since the RHR system will be required to augment the spent fuel cooling system for some perf M of time followiag a discharge, describe and discuss how it will be verified that the decay heat load has decayed to a value within the et2pacity of the spent fuel pool cooling system and, therefore, allowing the RlIR system to be safely returned to its safety function mode of operation.

Response: It has been CECO's experience that the RHR is not required for either a reload or full core discharge. It was required, its use would be phased ouc by throttling back the PJIR and observing if the pool temperature remains stable. If it is stablo, the spool pieces would be removed and the RHR returned to its safety function.

1 4

O i

,O l

12-7 l

12.3 Questions from T. A. Ippolito to J. S. Abel transmitted on D May 19, 1981

\ .

12.3.1 Question:

Discuss in some detail, the procedure that will be used for (1) removal of the fuel rods from the present racks, (2) removal and disposal of the racks themselves (i.e., rating them intact or cutting and drumming them), (3) installation of the new high density racks and (4) loading them with the presently stored spent fuel rods. In this discussion include, in a step by step fashion, the number of people involved in each step of the procedure including divers if necessary, the dose rate they will be exposed to, the time spent in this radiation field and the estimated man-rem re quired for each step of the operation.

Response: Later 12.3.2 Question:

Demonstrate that the method used for removal and disposal of the old racks will provide ALARA exposure.

Response Later 12.3.3 Question:

What radiation levels will be used to determine whether the racks to be i disposed are identified as clean or radioactive racks.

Response: 1000 DPM per cm is considered clean.

12.3.4 Question:

Identify (p ci/cc)the important in the radionuclides spent fuel and tgep pgegentCs,SE"#8" pool water ir.cluding Cs, Co, and#*NCo.

What is the external dose equivatne (DE) rate (mrem /hr) from these radionuclides. Consider these DE rates at the edge and center of the pool.

Response: Later 12.3.5 Question:

Provide an estimate of the increase in annual man-rem from more frequent changing of the demineralizer resin and filter cartridge.

Response: As discussed in Section 8 of Revision 1 of the Licensing Report, the proposed modification will have a negligible annual effect on the pool cleanap system; therefore, there is expected to be no increase in the annual frequency of changing of the filter demineralizer resin.

12.3.6 Question:

Discuss the build-up of crud (e.g., Co, Co) along with the sides of the pool and the removal methods that w'.ll be used to reduce radiation levels at the edge of the pool to ALARA.

12-8

i Response: A buildup of crud as a result of this proposed modification would

/"'N mean that the concentration of crud in the pool water has increased.

(~s/ Because the cleanup system removes essentially all crud deposited in the pool water from one refueling long before the next refueling, l a measurable buildup will not occur. (See Section 8 of Revision 1 l of the licensing submittal.) In additon, operating experience to date indicates no significant buildup of crud along the sides of the pool.

12.3.7 Question:

Provide an estimate of the total man-rem to be received by personnel oc cupying the spent fuel pool area based on all operations in that area in I cluding those resulting from 4, 5, and 6 above. Describe the impact of the modification on these estimates.

l l

Response: Later 12.3.6 Question l Tdentify the monitoring systems that will be used, and its location in the spent fuel pool area, that would warn personnel whenever there is an inadvertent increase in radiation levels that could trigger the alarm set-point.

t Response: There are six monitoring systems with set-points of 5 mr/hr to 100 mr/hr precently monitoring the spent fuel pool area. These are (s deemed adequate for personnel protection.

s 12.3.9 Question:

Describe the methods used to preclude spent fuel pool water from overload ing onto the spent fuel pool area floors.

Response: There are skimmers and a surge tank which will take up water displaced by the new racks.

12.3.10 Question:

Specify the present dose rate in occupied areas outside the spent fuel pool concrete stleid wall and provide an estimate of the potential increase of this dose rate if che space between ;he spent fuel and inside concrete shield wall is reduced due to the modification.

Response: The present (5/26/81) dose rates everywhere outside the spent fuel pool shield walle are 2 mr/hr. As seen in Figures 2.1 and 2.2 of l the licensing submittal, there are at least nine inches of water between the outside of the new spent fuel racks and the thick, l concrete walls of the spent fuel pool. This amount of water plus j the concrete supplies sufficient attenuation that the dose rate l

outside the walls is negligible and changes in this dose rate due to

! increased spent fuel storage are not measurable. Also, there are no ncemally occupied spaces immediately adjacent to the concrete shield walls.

12-5

12.4 Questions from T. A. Ippolito to J. S. Abel transmitted on June 16, 1981 v

12.4.1 -Question:

Describe the samples and instrument readings and the frequency of measure ment that are performed to monitor the water purity and need for spent fuel pool cleanup system demineralize. resin and filter replacement. How will these be affected by the proposed action?

Response: Later 12.4.2 Question:

State the chemical and radiochemical limits to be used in monitoring the spent fuel pool water and initiating correcting action. Provide the basis for establishing these limits, giving consideration to conductivity, gross gamma and iodine activity, demineralizer and/or filter differential pres sure, demineralizer decontamination factors, pH, and crud level.

Response: Later >

O O

12-10

Fa.se

() 8.3 Consequences of Failed Fuel .............. ........... 8-3 8.3.1 Me th od s o f Analys i s . . . . . . . . . . . . . . . . . . . . . . . . . . 8- 5 8.3.2 Fission-Product Radionuclide Concentrations .. 8-6 8.3.3 Gaseous Releases from Failed Fuel ............. 8-7 8.4 Exposure for the Installation of New Racks ........... 8-8 0.5 Conclusions ......................................... 8-9 References .......................................... 8-10

(

9. POOL STRUCTURAL CALCULATIONS (Later) ...................... 9-1 I

i 10. INSERVICE SURVEILLANCE PROGRAM FOR BORAFLEX NEUTRON ABSORBING MATERIAL ........................................ 10-1 10.1 Program Intent ....................................... 10-1 10.2 Description of Specimens ............................. 10-1 l

~

10.3 Test ................................................. 10-1 10.4 Specimen Evaluation .................................. 10-2

11. COST / BENEFIT ASSESSMENT ................................... 11-1 11.1 Specific Needs for Spent Fuel Storage ................ 11-1 l 11. 2 Co s t o t Mod i f ica t ion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11-2 11.3 Alternatives to Spent Fael Storage Expansion ........ 11-2

( 11.4 Resource Commitments ................................. 11-4 l 11.5 Environmental Effects ............................... 11-4 1

References ...................*........................ 11-6

12. RESPONSES TO NRC QUESTIONS ............................... 12-1 I

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