ML20217H829

Application for Amends to Licenses DPR-62 & DPR-71,approving Method of Transferring Spent Fuel Shipping Cask

ML20217H829
Person / Time
Site:	Brunswick
Issue date:	08/06/1997
From:	Hinnant C CAROLINA POWER & LIGHT CO.
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
Shared Package
ML20217H831	List: BSEP-97-0319, Application for Amends to Licenses DPR-62 & DPR-71,approving Method of Transferring Spent Fuel Shipping Cask ML20217H844
References
BSEP-97-0319, BSEP-97-319, EIB-96-002, EIB-96-2, NUDOCS 9708130283
Download: ML20217H829 (8)

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cpaL Carolina Power & Light Company C. S. Hinnant PO Box 10429 Vce President southport. NC 28461-0429 Brunseck steam Electre Plant AUG 061997 SERIAL: BSEP 97-0319 U. S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, DC 20555 BRUNSWICK STEAM ELECTRIC PLANT, UNIT NOS.1 AND 2 DOCKET NOS. 50-325 AND 50-324/ LICENSE NOS. DPR-71 AND DPR-62 REQUEST FOR LICENSE AMENDMENT SPENT FUEL CASK HANDLING DESIGN AND LICENSING BASIS ISSUES Gentlemen:

The purpose of this submittalis to request a license amendment for an unreviewed safety question associated with handling of the spent fuel shipping cask at the Brunswick Steam Electric l Plant (BSEP), Unit Nos.1 and 2. In a letter to the NRC dated November 16,1982, Carolina Power and Light (CP&L) Company stated that:

..the cask redundant lifting yoke and the work redundant lifting rig are of redundant design, and the crane on which they are used is single failure proof.

Therefore, a load drop with regard to equipment handled by the above systems is not considered credible.

In preparing the BSEP response to an NRC Request for Additionallnformation (RAI) regarding NRC Bulletin 96-02, " Movement of Heavy Loeds Over Spent Fuel, Over Fuelin the Reactor Core, or Over Safety Related Equipment,"it was determined that site procedures allowed for the lifting and loading of an IF-300 spent fuel shipping cask with only the primary yoke, (i.e., a configuration which is not single failure proof) during transfer from the tilting cradle to the secondary yoke. This I transfer occurs on the 20 foot elevation of the Reactor Building at a lift height of approximately 7 feet. By letter dated February 7,1997, (Serial: BSEP 97-0039), CP&L presented these findings to the NRC. This response indicated that damage resulting from a spent fuel shipping cask drop ,

would not preclude the operation of sufficient equipment needed to achieve safe shutdown due to y)) f equipment redundancy. In addition,it was concluded that the affect on cask integrity of a cask 4 drop during the transferwould be bounded by the 30 foot drop accident postulated in NEDO-10084-4," Vectra IF-300 Shipping Cask Consolidated Safety Analysis Report."

Following the submittal of February 7,1997, communications occurred with Shearon Harris Nuclear Power Plant and H. B. Robinson Steam Electric Plant personnel regarding concerns associated with a spent fuel shipping cask drop with less than full cask integrity (i.e., valve box covers removed). An evaluationwas performed to determine if similar concerns existed at BSEP.

On May 6,1997, it was determined that the 30 foot drop analysis is only bounding if the valve box covers are installed during spent fuel shipping cask handling operations. Site procedures have allowed lifting and loading of an IF-300 spent fuel shipping cask with the valve box covers 9708130283 970806 PDR ADOCK 05000324 P PDR l llfhl[hlf

Document Control Desk BSEP 97-0319 / Page 2 removed, during the transfer from the tilting cradle to the secondary yoke. This event was reported in accordance with the requirements of 10 CFR 50.73(a)(2)(ii)in that lifting a spent fuel shipping cask with a non single failure proof rigging and without the valve box covers inttalled

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represents a condition outside of the design bases, since this scenario was not bounded by '

existing analyses (Licensee Event Report 1-97-004, dated June 5,1997 (Serial: BSEP 97 0235)).

This issue has been determined to represent an unreviewed safety question. However, further analysis has been performed and it has been determined that the design of the primary yoke, previous load tests, and periodic inspections ensure that a drop of the spent fuel shipping cask is not a credible event. Therefore, this issue does not represent a condition outside of the design bases. As described abovo, the sequence used to transfer between the tilting cradle and seconda y yoke requires a lift with a single lifting device, which has not been reviewed by the NRC. In accordance with 10 CFR 50.90 and 10 CFR 2.101, CP&L is requesting a license amendment for BSEP Unit No.1 and BSEP Unit No. 2 approving the method of transferring the cask that is described herein. This amendment does not require a revision to the plant Technical Specifications.

CP&L is providing, in accordance with 10 CFR 50.91(b), Mr. Mel Fry of the State of North l Carolina with a copy of the proposed license amendmerf, l'

CP&L requests that the proposed amendment be approved by September 30,1997, to support  ;

the current spent fuel shipping schedule.

Please refer any questions regarding this submittal to Mr. Keith Jury, Manager - Regulatory Affairs, at (910) 457-2783.

I Sincerely, C. S. Hinnant

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Document Control Desk -

BSEP 97-0319 / Page 3 JGT/jgt

Enclosures:

1. Basis for Change Request

2. 10 CFR 50.92 Evaluation

3. EnvironmentalConsiderations

4. Engineering Service Request (ESR) 97-00362 Revision 0 IF 300 Cask Design, Testing and inspection C. S. Hinnant, having been first duly sworn, did depose and say that the information contained herein is true and correct to the best of his information, knowledge and belief; and the sources of his information are officers, employees, and agents of Carolina Power & Light Company.

new Idud Notary (Seal) 0-My commission expires: b I1; S003 -

).

l,

Document Control Desk -

BSEP 97-0319 / Page 4 -

pc (with enclosures);

- U. S. Nuclear Regulatory _ Commission, Region II -

ATTN.: Mr. Luis A. Reyes, Regional Administrator

- Atlanta Federal Center 61 Forsyth Street, SW, Suite 23T85

Atlanta, GA 30303 -

U. S. Nuclear Regulatory Commission ATTN: _ Mr. C. A Patterson, NRC Senior Resident inspector l 8470 River Road i

Southport, NC 28461 U. S. Nuclear Regulatory Commission ATTN.: Mr. David C. Trimble, Jr. (Mail Stop OWFN 14H22) 11555 Rockville Pike Rockville, MD 20852 2738 i The Honorable J. A. Sanford Chairman - North Carolina Utilities Commission P.O. Box 29510 -

Raleigh, NC 27626-0510

. Mr. Mel Fry Director - Division of Radiation Protection North Carolina Department of Environment, Health, and Natural Resources 3825 Barrett Drive -

Raleigh, NC 27609-7221 '

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ENCLOSURE 1 BRUNSWICK STEAM ELECTRIC PLANT, UNIT NOS.1 aND 2 NRC DOCKET NOS. 50-325 AND 50-324 OPERATING LICENSE NOS. DPR 71 AND DPR-62 REQUEST FOR LICENSE AMENDMENTS SPENT FUEL CASK HANDLING DESIGN AND LICENSING BASIS ISSUES BASIS FOR CHANGES Description of Spent Fuel Shipping Cask Handling The (empty) spent fuel cask is delivered to the plant on a railcar which enters the Reactor Building through the airlock on the 20 foot elevation. The cask is transported in a horizontal position. The railway car is positioned under the equipment access hatch to facilitate handling.

After inspection and removal of any crash structure and tie-downs, the valve box covers are l removed and the cask is raised to a vertical position using the primary yoke (which is non-l redundant). The primary ycke is used to lift the cask from the tilting cradle and place it in the secondary yoke which is also on the rail car. In order to make this move, the cask must be raised about 7 feet. Once the secondary yoke is engaged, the lifting device has redundant lifting capability. The cask is then lifted through the equipment hatch to the refuel floor on the 117 foot elevation, and placed in the decontamination area. After cleaning and inspection of the cask, the head bolts are loosened and the cask is lifted using the double yoke and placed in the fuel pool.

in the fuel pool, the lifting, yoke is detached, the closure head is removed, and the fuel bundles are loaded into the cask. The cask closure head is then set in place on the cask, and the lifting yoke is attached. The cask is raised to permit placement of some of the head bolts or nuts. As cask raising continues, the cask is hosed down and the radiation dose rate monitored. The cask is then moved to the decontamination area and surfaces are decontaminated. After decontaminaton is completed, the remaining head bolts or nuts are installed and tightened, and the cask is checked for surface contamination.

The unloading process described above is reversed for loading the cask onto the railcar. The cask is lowered to the railcar on the 20 foot elevation using the redundant yoke. The primary yoke (which is non-redundant) is used to lift the cask from the secondary yoke to the tilting cradle which is also on the railcar, and to lower the cask to the horizontal position for shipping.

At this time, the valve box covers are installed. After cask temperature and pressure have been monitored and verified to be acceptable, tie down bolts are installed and shipping placards attached.

Analysis Lifting and loading of an IF-300 spent fuel shipping cask with only the primary yoke (i.e., a l configuration which is not single failure proof) during transfer from the tilting cradle to the I secondary yoke is a lift that has not been reviewed by the NRC. An analysis has been E1-1

performed that demonstrates that for the non-redundant configuration used for this lift, a cask drop is not a credible event.

ANSI N14.6 requires safety factors of three with respect to yield strength and five with respect to ultimate strength for redundant lifting devices. These safety factors are to be doubled for non-redundant lifting devices. For materials with yield strengths in excess of 80% of their ultimate strengths, the safety factor limits discussed above do not apply. Design for these materials are based on the material's fracture toughness, with a criteria established by the designer. The materials used to fabricate the primary yoke Cross Member, Arms, and J-hooks do havo yield strengths greater than 80% of their ultimate strengths, in addition, NUREG-0612, Section 5.1.1(4), states that "For operating plants certain inspections and load tests may be accepted in lieu of certain material requirements in the standard." Since NUREG 0612 was issued after manufacture of the yoke, this provision is applicable.

Each component of the primary yoke is listed below, with a description of the material and the safety factors with respect to yield strength based on static loading:

Component Material Yield Safety Strength Factor Cross Member A514 90 ksi 7.92 Arms A514 90 ksi 20.52 J-hooks A514 90 ksi 3.63 l

Yoke Pin 4340 steel 125 ksi 6.21 Welds (worst case) (not avail.) (not avail.) 6.18 Critical components are inspected annually by dye penetrant or magnetic particle testing. After fabrication the yoke assembly was load tested to 200% of rated load (rated load is 140,000 lb.). A fracture analysis was performed for the J-hooks, cross members and arms. This analysis demonstrated that with worst case stresses on the hooks, failure due to unstable crack propagation will not occur.

In summary, the substantial safety factors for each component, the 200% load test that has been performed, the analysis of selected components under maximum postulated loads, and an inspection program which complies with ANSI N14.6 provide a high level of confidence that the primary yoke will not fail. Further the sequence of removal of the valve box covers is not an issue.

Engineering Service Request (ESR) 97-00362 "lF-300 Cask Design, Testing and inspection," which is provided as Enclosure 4 to this letter, documents the analysis summarized above.

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- ENCLOSURE 2 BRUNSWICK STEAM ELECTRIC PLANT, UNIT NOS.1 AND 2 NRC DOCKET NOS. 50-325 AND 50 324 OPERATING LICENSE NOS. DPR-71 AND DPR-62 REQUEST FOR LICENSE AMENDMENTS SPENT FUEL CASK HANDLING DESIGN AND LICENSING BASIS ISSUES 10 CFR 50.92 EVALUATION 10 CFR 50.92 provides s'andards for determining whether a significant hazards consideration exists. A proposed amendment to an operating license for a facility involves no significant '

hazards consideration if operation of the facility in accordance with the proposed amendment would not: (1) involve a significant increase in the probability or consequences of an accident previously evaluated, (2) create the possibility of a new or different kind of accident from any accident previously evaluated, or (3) involve a significant reduction in a margin of safety.  !

l Carolina Power & Light (CP&L) Company has reviewed this proposed license amendment and concluded that adoption of the amendment does not involve a significant hazards consideration.

The basis for this determination follows.

1. The proposed license amendment does not involve a significant increase in the probability or consequences of an accident previously evaluated. Originally, a cask drop 3 was not deemed a credible accident because the cask redundant lifting yoke is of redundant design and the crane on which it is used is single failure proof. Although a non-redundant lift is involved during transfer of the cask from the tilting cradle to the secondary yoke, analysis indicates that based on the design of the primary yoke, previous load tests, and a thorough inspection program, a drop of the spent fuel shipping cask is not credible. A non-redundant lift is assumed to have a slightly higher probability -

of failure than a redundant lift. However, the increased potential for a drop resulting from a non-redundant lift is not significant. Therefore, the proposed license amendment does not involve a significant increase in the probability or consequences of an accident previously evaluated.

2. The proposed license amendment will not create the possibility of a new or different kind of accident from any accident previously evaluated. CP&L has demonstrated that a cask drop accident is not credible using the existing procedures for spent fuel shipping cask handling at BSEP. Therefore. the proposed license amendment will not create the possibility of a new or different kind cf accident from any accident previously evaluated.

3. The proposed license amendment does not involve a significant reduction in a margin of safety. Originally, a cask drop was not deemed a credible accident because the cask redundant lifting yoke is of redundant design and the crane on which it is used is single failure proof. Although a non-redundant lift is involved during transfer of the cask from the tilting cradle to the secondary yoke, a drop of the spent fuel shipping cask is not credible based on the design of the primary yoke, previous load tests, and a thorough inspection program. Since the cask drop remains a non-credible event, the proposed amendment does not result in a reduction of the margin of safety.

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ENCLOSURE 3 BRUNSWICK STEAM ELECTRIC PLANT, UNIT NOS,1 AND 2 NRC DOCKET NOS. 50-325 AND 50-324 OPERATING LICENSE NOS. DPR-71 AND DPR 62 REQUEST FOR LICENSE AMENDMENTS SPENT FUEL CASK HANDLING DESIGN AND LICENSING BASIS ISSUES ENVIRONMENTAL CONSIDERATIONS 10 CFR 51.22(c)(9) provides criteria for t nd identification of licensing and regulatory actions eligible for categorical exclusion from pe> forming an environmental assessment. A proposed amendment to an operating license for a facility requires no environmental assessment if operation of the facility in accordance wi h the proposed amendment would not: (1) involve a significant hazards consideration, (2) ret uit in a significant change in the types or significant increase in the amounts of any effluents '. hat may be released offsite, or (3) result in an increase in individual or cumulative occupational radiation exposure Carolina Power &

Light (CP&L) Company has reviewed this request and concluded that the proposed license amendment meets the eFaibility criteria for categorical exclusion set forth in 10 CFR 51.22(c)(9). Pursuant to 10 CFR 51.22(b), no environmental impact statement or l_ environmental assessment needs to be prepared in connection with the issuance of the amendment. The basis for this determination follows.

1. The license amendment does not involve a significant hazards consideration, as shown in Enclosure 2.

2. The proposed license amendment does not result in a significant change in the types or a significant increase in the amounts eT any effluent that may be released offsite. The proposed license amendment does not introduce any new equipment nor does it require any existing equipment or systems to perform a different type of function than they are presently designed to perform. The proposed license amendment does not alter the function of existing equipmLnt and will ensure that the consequences of any previously evaluated accident do not increase. CP&L has demonstrated that a drop of the spent fuel shipping cask remains a non-credible event. Therefore, CP&L has concluded that there will not be a significant increase in the types or amounts of any effluent that may be released offsite and, as such, does not involve irreversible environmental consequences beyond tnose already associated with normal operation.

3. ' - The license amendment does not result in an increase in individual or cumulative occupational radiation exposure.

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