ML20138N126

Discusses Rev 2 to SER Re Heavy Load Handling Inside Containment.Info No Longer Required Based on Generic Ltr 85-11.Util Already Provided Info Required by Generic Ltr 81-07

ML20138N126
Person / Time
Site:	Three Mile Island
Issue date:	10/31/1985
From:	Standerfer F, Standerfer P GENERAL PUBLIC UTILITIES CORP.
To:	Travers W Office of Nuclear Reactor Regulation
References
REF-GTECI-A-36, REF-GTECI-SF, RTR-NUREG-0612, RTR-NUREG-612, TASK-A-36, TASK-OR 0342A, 342A, 4410-85-L-0211, 4410-85-L-211, GL-81-07, GL-81-7, GL-85-11, NUDOCS 8511050075
Download: ML20138N126 (4)

Text

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r GPU Nuclear Corporation g g{ Post Office Box 480 Route 441 South Middletown, Pennsylvania 17057 0191 717 944 7621 TELEX 84 2386 Writer's Direct Dial Number:

(717) 948-6461 4410-85-L-0211 Document 10 0342A October 31, 1985 ut n .

._4 'j .1 y d.?

TM1 Program Office O Attn: Dr. W. D. Travers T.,

Acting Director g

US Nuclear Regulatory Commjssion ,

c/o Three Mlle Island Nuclear Station U Middletown, PA 17057

Dear Dr. Travers:

Inree Mjle Island Nuclear Station, Unit 2 (THI-2)

Operating License No. OPR-73 Docket No. 50-320 Safety Evaluation deport of Heavy Load Handling Inside Containment, Revisjon 2 Reference 1 requested additional information concerning the consequences of heavy load drops. The additional information requested is part of the Phase 11 submittal that was originally required by Generic Letter 81-07.

It is our position that this information is no longer required based on Generic Letter 85-11 which was determjned to be applicaDie to THI-2 by Reference 2. Generic Letter 85-11 stated that utilities need only address Section 5.1.1 of NUREG-0612, which is the Phase I submittal jdentified in Gent tic Letter 81-07.

Compliance with Generic Letter 81-07 has been the subject of extensive correrpondence between GPU Nuclear and the NRC. Reference 3 stated that al.1. t acairements of the generic letters had been satisfjed for activitjes up e defueling and requested additjonal information to address defueling activities. That information has been provided by GPU Nuclear.

Reference 4 provided a descrjptjon of load handijng equipment and the load path assocjated with the handling of defueling canisters. It also addressed the administrative measures to be jmplemented for handling heavy loads associated witn defueling activities. Reference 5 described tne generic load paths for activitjes associated with defueling. In O

er 10 D l at . ucioar Corporation is a subsidiary of the General Public Utilities Corporation kg

Or. W. D. Travers October 31 , 1985 4410-85-L-0211 1

comoination, tne information provided by References 3, 4 and 5 satisfies the requirements of Generic Letter 81-07, as modified by Generic Letter 85-11, for defueling activities.

As noteJ aDove, the information requested by Reference 1 deals with Phase II subjects (i.e., the effects of load drops) and need not be addressed based on Reference 2. However, GPU Nuclear has considered the Phase 11 requirements and concluded that the intent of the Phase 11 requirements has been satisfied. The means by which the intent of the reouirements addressed in Reference 1 has been satisfied is provided below.

Section 5.1 (II) of NUREG-0612 establishes ae k rr limit of 0.95 or less following a neavy load drop. GPU Nuclear understands the intent of this limit is to ensure that the fuel will not experience a criticality event with a release of fission products as a result of a heavy load drop. ,

Reference 6 presents the results of various critjcality analyses associated with the defueling canisters, including when the canisters are

) in the storage racks. These results indjcate ke rr is less than 0.95 as i

long as the water remains in the spent fuel rol and the spacing of the canisters within the racks remains unchanged. Reference 4 limits the loads tnat can be handled over the racks to ensure spacing of the canisters within the racks will remain unchanged. Should a load drop cause draining of the spent fuel pool without altering the spacing of the canisters witnin the racks, Reference 6 indicates kerr is equal to 0.964 based on a conservative analysjs. References 7 and 6 document the bases for concluding that the fuel will remain below 0.99 in any l conceivable configuration providing surrounding water is borated to 4350 i ppm. dased on these results, GPU Nuclear has demonstrated that a heavy 1 load drop associated with defueljng activities will not result jn a l

criticality in the damaged TMI-2 fuel; thus, the intent of Section 5.1 I (II) of NUREG-0612 is satisfied.

j Section 5.1 (III) of NUREG-0612 calls for water leakage to be limited so as not to uncover the fuel. GPU Nuclear understands the intent of this 4

requirement is to prevent fuel damage and the release of fission products (see Section 2.3 of NUREG-0612). Reference 9 estimates that the total i

decay heat remaining in the TMI-2 fuel as of July 1985 is about 15 kw based on a conservative ANSI model. Assuming the fuel is evenly l distributed in 150 canisters (versus the estimated 250 plus canjsters to De used), the decay heat content of each canister would be about 100 watts. The amount of residual decay heat would not result jn damage to tne defueling canisters, if uncovered; therefore, this conditjon would not result in the release of additional fjssion products. Thus, draining the spent fuel pool will not cause additjonal fuel damage or the release of fission products and there is no need to ensure adequate makeup capability for leaks which could result from a load drop jnto the spent fuel pool. Since GPU Nuclear has demonstrated that adequate makeup capability exjsts to manage load drops jnto the reactor vessel (Hererence

7) and makeup capaollity is not required for load drops jnto the spent fuel pool, tne jntent of Sectjon 5.1 (III) has been met.

e Dr. W. D. Travers .5- October 31, 1985 4410-85-L-0211 In conclusion, GPU Nuclear nas provided the information required jn response to Generic Letter 61-07, as modified by Generic Letter 85-11.

Further, altnough not specifically required of GPU Nuclear, the aoove information provides demonstration tnat the jntent of Sections 5.1 (II) and 5.1 (III) of NUREG-0612 have been satisfied.

Sincerely,

. H. Standerfe Vice President / Director, TMI-2 FRS/RdS/eml t

1

. ATTACHMENT (4410-85-L-0211)

REFERENCES:

1. NRC/TMI-85-078, W. D. Travers to F. R. Standerfer, " Safety Evaluation Report for Heavy Load Handling Inside Containment, Revision 2", dated Octooer 18, 1985.

2. NRC/TMI-85-198, B. J. Snyder to F. R. Standerfer, " Applicable Generic Letter - January 1, 1985 througn June 30, 1985," dated July 17, 1985.

3. NRC letter, B. J. Snyder to 8. K. Kanga, " Control of Heavy Loads", dated January 5, 1984.

4. Safety Evaluation Report for Early Defueling of the THI-2 Reactor Vessel, GPU Nuclear letter 4410-85-L-0091, dated May 20, 1985.

5. Safety Evaluation Report for Heavy Load Handling Inside Containment, Revision 2, GPU Nuclear letter 4410-85-L-0172, dated September 11, 1985.

6. Defueling Canisters Technical Evaluation Report, GPU Nuclear letter 4410-85-L-0183, dated Septencer 10, 1985.

7. Safety Evaluation Report for Load Handling over the Reactor Vessel, 15737-2-G07-110, Revision 0, dated April 6,1985.

8. TMI-2 Criticality Analysis, GPU Nuclear letter 4410-84-L-0199, dated Novemoer 6, 1984

9. Safety Evaluation Report for the TMI-2 Reactor Vessel Head, 4350-3221-61-4, Revision 6, dated May 1984.