ML20079J411

Forwards Responses to Auxiliary Sys Branch Questions 410.94 Through 410.99 Re Spent Fuel Storage,Transmitted by .Responses Will Be Incorporated in FSAR Revision Scheduled for Jan 1983

ML20079J411
Person / Time
Site:	Limerick
Issue date:	12/22/1982
From:	Bradley E PECO ENERGY CO., (FORMERLY PHILADELPHIA ELECTRIC
To:	Schwencer A Office of Nuclear Reactor Regulation
References
NUDOCS 8212280209
Download: ML20079J411 (10)

Text

4 'm se , 4 PHILADELPHIA ELECTRIC COMPANY 2301 MARKET STREET P.O. BOX 8699 PHILADELPHI A. PA.19101 C DW A R D G. B AU ER, J R.

1215)841-4000

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...s.s CUGENE J. BR ADLEY

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December 22 I 1982 DON ALD BLANMEN CUDOLPH A. CHILLEMI C. C. MIR pr H ALL T. H. M AM ER CORN ELL PAU L AUERS ACSG AssesTANT ..esana6 c ouns.6 EDW ARD J. CULLEN JR.

THOM AS H. MILLER, J R.

IKENE A. McMENN A Assesvant c.ums.6 Mr. A. Schwencer, Chief Docket Nos. 50-352 Licensing Branch No. 2 50-353 Division of Licensing U. S. Nuclear Regulatory Commission Washington, D. C. 20555

Subject:

Limerick Generating Station, Units 1 and 2 Request for Additional Information from Auxil_ary Systems Branch

Reference:

A. Schwencer to E. G. Bauer, Jr. letter dated November 17, 1982

Dear Mr. Schwencer:

1 In order to expedite your review, Philadelphia Electric Company  ;

is transmitting herewith our responses to questions 410.94 thru 410.99, which were received by us via the reference letter on November 22, 1982.

These responses will be incorporated in the FSAR Revision scheduled for January, 1983.

Vary truly yours, d cy LN/pb/C-3 I

cc: See attached service list l l

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+ 8212280'209 821222 ..

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i PDR ADOOK 05000352  ;

A P D R _...

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cc: Judge Lawrence Brenner (w/o enclosure)

Ju'dge Richard F. Cole (w/o enclosure)

Judge Peter A. Morris (w/o enclosure)

Troy B. Conner, Jr. , Esq. (w/o enclosure)

Ann P. Ilodgdon (w/o enclosure)

Mr. Frank R. Romano (w/o enclosure)

Mr. Robert L. Anthony (w/o enclosure)

Mr. Marvin I. Lewis (w/o enclosure)

Judith A. Dorsey, Esq. (w/o enclosure)

Charles W. Elliott, Esq. (w/o enclosure)

Mr. Alan J. Nogee (w/o enclosure)

Robert W. Adler, Esq. (w/o enclosure)

Mr. Thomas Gerusky (w/o enclosure)

Director, Pennsylvania Emergency Management Agency (w/o enclosure)

Mr. Steven P. liershey (w/o enclosure)

James M. Neill, Esq. (w/o enclosure)

Donald S. Bronstein, Esq. (w/o enclosure)

Mr. Joseph 11. White, III (w/o enclosure)

Dr. Judith 11. Johnsrud (w/o enclosure)

Walter W. Cohen, Esq. (w/o enclosure)

Robert J. Sugarman, Esq. (w/o enclosure)

Rodney D. Johnson (w/o enclosure)

Atomic Safety and Licensing Appeal Board (w/o enclosure)

Atomic Safety and Licensing Board Panel (w/o enclosure)

Docket and Service Section (w/o enclosure)

LGS FSAR QUESTION 410.94 h'e have noted that you are the first applicant to state that no fuel will be stored in a new fuel vault. FSAR Amendment 10 states that the new fuel will be stored in the spent fuel pool, a) Verify that no fuel will be stored in the new fuel storage vault.

b) Provide a justification for not having and using a new fuel storage vault.

c) Provide a description of the physical modifications to the vault which will prevent any fuel bundle from being stored in the vault.

RESPONSE

a) There is no new fuel storage vault and there are no new fuel storage racks.

b) The justification for not having a new fuel storage vault is that in our experience at Peach Bottom the vault racks provided no technical or operational benefits. Plant personnel experienced maneuverability problems when trying to use the new fuel vault and consequently recommended this storage space be used for other storage purposes.

Section 9.1.4 describes Receipt Inspection and llandling of new fuel within the reactor enclosure. New fuel is delivered to a receiving station where the fuel crates are unloaded and examined for damage during shipment. The fuel crates are then brought up to the refueling floor through the equipment hatches where the crates can be stored until the new fuel is inspected, channeled and transferred into the spent fuel pool storage racks.

c) The new fuel storage racks have been either sold or scrapped. Storage of new fuel bundles in the storage vault is prohibited by existing fuel handling procedures which require new fuel to be stored in the spent fuel pool.

LGS FSAR QUESTION 410.95 The FSAR Amendment 10 removed the statement that a fuel bundle cannot be inserted anywhere other than a designated storage location. Removing this statement implies that fuel could be placed in the pool in a location not designated as a storage location, such as along the pool walls. Verify that a fuel bundle cannot be inserted anywhere other than a designated storage location. As an alternate, provide a discussion of every location other than a designated storage location where fuel can be placed. The discussion should include the effect on keff, interlocks, fuel support structure (2), administrative procedures, and the configuration of the fuel in terms of number and location of the bundles. Provide drawings which show all locations which are not designated storage locations and seismic Category I supports for each bundle.

RESPONSE

Our removal of the statement that a fuel bundle cannot be inserted anywhere other than a designated storage location did not imply that a fuel bundle could be placed in the pool in a location not designated as a storage location. Section 9.1.2.1.e simply says that the insertion of a fuel bundle into any open rack location is permitted and not restricted by criticality considerations (9.1. 2. 3.1.1) .

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LGS FSAR QUESTION 410.96 The FSAR, by Amendment 10, reduced the uplift force which could.be applied.to the spent fuel racks without damaging

, the racks to 1,250. pounds. The FSAR states that the lifting bail yields.at an uplift force greater than 1,500 pounds.

Specify the force'at which the lifting bail yields and the damage to the racks with the lifting bail yield force applied to it.

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RESPONSE

Section.9.1.2.3 has been revised to show that the spent fuel racks are capable of withstanding, without damage, an uplift force of 4,500 pounds. The upward force at which plastic deformation of the bail begins is not precisely known. It i

should be noted, however, that the hoist of the refueling crane is equipped with a load cell interlock switch which i

prevents upward movement of the hoist with loads in excess of 1,200 pounds. Section 9.1.2.3.2.1 has been revised to

, show that the maximum uplift force of the refueling crane j is 1,200 pounds.

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LGS FSAR The design of the spent fuel pool provides enough reinforcement

'- in the concrete to withstand the thermal stresses resulting from pool boiling.

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W;-*]"ith:t:n_th; A--

• "'- uplift l The spent fue storage rack is

,  :~ . force of pounds and a horizontal force of 1000 pounds. l Lead-in and lead-out guides at the top of the racks provide

- - guidance of the fuel assembly during insertion or withdrawal. If there is a stuck fuel assembly, the lifting bail yields at an uplift force greater than 1500 pounds. ,

9.1.2.3.1 Criticality Control l 9.1.2.3.1.1 Basic Assumptions of Criticality Analysis l The geometry of the spent fuel storage array is such that K eff will be 5 0.95. To ensure that the design criteria are met, the following normal and abnormal spent fuel storage conditions were analyzed:

a. Normal positioning in the spent fuel storage array l

b. Pool water temperature increases to 2120F l

c. Abnormal positioning in the spent fuel storage array l e-- d. Dropped fuel bundle adjacent to storage area l

e. Dropped fuel bundle on top of and through fuel storage racks.

To ensure that the analysis followed a conservative approach and conformed to the general guidelines of criticality safety ana ysis, the calculations were performed using the following criteria:- -

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1) A uniform 3.5 w/o enriched U-235 distribution in an l 8 x 8 bundle j

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_ __ _ 9.1-9 Rev. 10, 09/82

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( 9.1.2.3.2 Structural Analyses l 9.1.2.3.2.1 Bases for Analyses l The high density spent fuel storage racks are seismic Category I equipment as defined in Regulatory Guide 1.13. These racks are designed to withstand the effects of a design basis earthquake (DBE) and remain functional, in accordance with Regulatory Guide 1.29 and the Code of Federal Regulations, Title 10, Part 50.

The structure of the racks is designed to remain functional and to maintain the required spacing between stored fuel assemblies in the event of impact of a fuel bundle dropped on the racks from an elevation of 36 inches (maximum). In this case, local plastic deformation is allowed at the point of impact. The structure of the racks is also analyzed for effects of the impact of a fuel bundle dropped through an empty storage cavity. Failure of a vertical fuel support is allowed in this case. A comparative analysis with the impact conditions, as stated above, is also conducted on a rack due to maximum uplift lb) of the refueling crane on a fuel bundle that is stuck. No permanent

< deformation is allowed in this case. 37 1200 All member and plate stresses for the above conditions are within the factored combination stress limits of Table 9.1-20.

a. Allowable stresses for aluminum members are based on the Aluminum Construction Manual Section 1 Specifications for Aluminum, l

9.1-19 Rev. 10, 09/82

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' LGS FSAR QUESTION 410.97 Verify that the keff for the spent fuel storage facility under optimum moderator conditions is less than .98.

RESPONSE

The final keff value for the spent fuel storage facility under optimum-moderator condition is .933. The criticality analysis for the storage racks took into account the conditions with uncertainties associated with the design and final adjusted keff value as described in Section 9.1.2.3.1.6. Since new fuel will be stored in the spent fuel pools, the NRC keff limit of .95 was used in the design for the spent fuel storage facility.

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LGS FSAR QUESTION 410.98 Please provide details on the verifications performed for the 4

criticality analysis methods. Include the experiments used and the results of the verification, including bias and un-certainty. Discuss any uncertainty included as a result of extrapolation to pool conditions (e.g., center-to-center spacing).

RESPONSE

Details concerning the verifications performed for the criticality analysis methods including experiments, results, bias and uncertainties can be found in Sections 9.1.2.3.1.1 through 9.1.2.3.1.6 and figures 9.1-26 through 9.1-29.

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.j LGS FSAR QUESTION 410.99 Has the effect of grain size been included in the evaluation of the boron worth. If so, provide the magnitude of this effect. If not, justify.the omission.

RESPONSE

As discussed in Section 9.1.2.3.1.4,_the effect of Boron grain size in the evaluation of the boron worth has been included in the final reactivity tabulation as found in Section 9.1.2.3.1.6. The magnitude of this effect is equal to a .005 ZL K bias.