ML20153D244

Affidavit of Jn Ridgely Supporting Util 860123 Motion for Summary Disposition of Contention 8 Re High Density Design of Fuel Racks

ML20153D244
Person / Time
Site:	Turkey Point
Issue date:	02/18/1986
From:	Ridgely J Office of Nuclear Reactor Regulation
To:
Shared Package
ML17342A383	List: ML20153D082 ML20153D108 ML20153D150 ML20153D172 ML20153D204 ML20153D244 ML20153D252
References
OLA-2, NUDOCS 8602240053
Download: ML20153D244 (8)

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UNITED STATES OF AMERICA NUCLEAR REGULATORY COMMISSION BEFORE THE ATOMIC SAFETY AND LICENSING BOARD In the Matter of )

) Docket Nos. 50-250 OLA-2 FLORIDA POWER & LIGIIT COMPANY ) 50-251 OLA-2

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(Turkey Po. int Plant, Units 3 and 4) ) (SFP Expansion)

AFFIDAVIT OF JOHN N. RIDGELY REGARDING CONTENTION 8 I, John N. Ridgely, being duly sworn, state as follows:

1. I am employed by the U.S. Nuclear Regulatory Commission as a Mechanical Engineer in the Plant Systems Branch, Division of BWR Licensing, Office of Nuclear Reactor Regulation. Prior to November 24,1985, I was a Mechanical Engineer in the Auxiliary Systems Branch, Division of Systems Integration , Office of Nuclear Reactor Regulation. A summary of my professional qualifications and experience is attached.

2. The purpose of this affidavit is to address Contention 8 with regard to the issue stated by the Licensing Board in its September 16, 1985 Order. With respect to Contention 8 I have read " Licensee's Motion for Summary Disposition of Intervenors' Contentions" and " Licensee's Statement Of Material Facts As To Which There Is No Genuine Issue To Be Heard,"

l dated January 23, 1985. Material Facts Nos.1-11 stated in relation to Conten-tion 8 are correct. I agree with the conclusions reached in the support-ing affidavit with the following exception. The zirconium-water reaction may occur at temperatures less than 1000 degrees F, but would be insignifi-cant with respect to the concern regarding cladding fires and explosions.

8602240053 860218 PDR ADOCK 05000250 g_ PDR

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3. Contention 8 states:

That the high density design of the fuel racks will cause higher heat loads and increase in water temperature which could cause ,

a loss-of-cooling accident in the spent fuel pool, which could in i turn cause a major release' of radioactivity to the environment.

And, that the decrease in the time that it takes the spent. fuel to reach its boiling point in such an accident, both increases  !

the probability of accidents previously evaluated and increase

[ sic] the chances accidents not previously evaluated.

As a basis for Contention 8, Intervenors allege that: -(1) the normal spent fuel pool water temperature should be kept below 122 degrees F and (2) the reduction in the time to spent fuel boiling from 15 hours1.736111e-4 days <br />0.00417 hours <br />2.480159e-5 weeks <br />5.7075e-6 months <br /> to 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> during a

" loss of cooling accident" will result in a major accident.

4. The Standard Review Plan (SRP) (NUREG-0800) Section 9.1.3 states that the spent fuel pool temperature should be limited to 140 degrees F for the normal maximum spent fuel heat load conditions. The normal maximum spent fuel heat load is the heat generated when- all storage cells in the storage pool are filled with spent fuel assemblies on the normal refueling schedule. The decay time of the respective batches is based on the anticipated intervals between refuelings. The decay time of the most

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recently discharged batches is based on the least time -interval between shutdown and when refueling commences plus the minimum time ' required to accomplish the discharge. This is normally assumed to be 150 hours0.00174 days <br />0.0417 hours <br />2.480159e-4 weeks <br />5.7075e-5 months <br />.

5. The pool temperature of 140 degrees F represents the maximum design temperature at which the spent fuel pool cleanup system can normally operate without degradation. The spent fuel pool cleanup system removes the impurities in the spent fuel pool water in order to maintain water clarity .j and to remove the impurities from. the pool water. The component which is sensitive to a water temperature of 140 degrees F is the resin in the.

demineralizer of the spent fuel pool cleanup system.

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i 6. The Staff's independent calculation, as stated in Section 2.7.2 of the NRC Safety Evaluation (SE), dated November 21, 1984, assumes a normal maximum heat load based on a half core discharge. The results show that the normal maximum pool water temperatures will be less than the 143 degrees F calculated by the Licensee. The normal maximum pool water temperature is expected to be 140.8 degrees F. We have performed a sensitivity analysis which indicates that the pool temperature is expected to remain above 140 degrees F for approximately 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> after the spent fuel is placed into the spent fuel pool.

7. The Licensee's calculations concerning the normal maximum pool water temperature (143oF) and the anticipated time required until the pool water temperature is less than 140 degrees F (72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />) are both higher and more conservative than the Staff's analysis which was performed consistent with the SEP and SRP Branch Technical Position ASB 9-2. Licensee's analysis and our independent analysis using similar assumptions used half-core reloads in lieu of the normal one third core reloads. If normal one third core reloads were used, the results of both analyses would have been less than the 140 degree F guideline. As stated in SE Section 2.7.2, the short period of time that the pool water is anticipated to be above the 140 degree F temperature specified in the SRP represents adequate justification for the Staff to conclude that the Licersee complies with the guidelines of the Standard Review Plan water temperature limit of 140 degrees F.

8. The spent fuel pool contains spent fuel which has decayed for varying lengths of time. As the length of decay time increases, the amount of heat generated by the spent fuel decreases, as shown in the Standard j Review Plan Branch Technical Position ASB 9-2. Therefore the ability of the 1

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1 fuel to produce heat decreases with time. A total loss of cooling to the spent fuel pool would result in the pool water - temperature increasing to I

boiling (212 degrees F).

9. As identified in Section 2.7 of the SE, the time required for the spent fuel pool to commence boiling is 7.6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> (not 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> as alleged by Intervenors) assuming the normal ' heat load. Once boiling starts, the significant pool water loss is due to boil off. As specified in the SE, the boil off rate is approximately 37.0 gallons per minute. ' Based on rough calculations, it is estimated that there is approximately 193,800 gallons of water in the spent fuel pool above the top of the spent fuel storage racks.

Based on this water volume it would take approximately three days and 15 hours1.736111e-4 days <br />0.00417 hours <br />2.480159e-5 weeks <br />5.7075e-6 months <br /> from the time the water reaches 212 degrecs F before the top of the racks are uncovered. Thus, it takes a total time of three days, 23 hours2.662037e-4 days <br />0.00639 hours <br />3.80291e-5 weeks <br />8.7515e-6 months <br /> for the pool water to commence boiling and the pool water level to boil off before the top of the spent fuel racks are exposed to the atmosphere.

10. Alakeup water to the spent fuel pool can be provided from the demineralized water system , the fire water system , the primary water .

system , or from the refueling water storage tanks. Given the number of different methods of providing makeup water, the Staff concludes that 7.6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> is adequate time to initiate makeup to the spent fuel . pool before a spent fuel pool would commence boiling. In the unlikely event that makeup water could not be provided within the 7.6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br />, there would be no detrimental effects on the spent fuel for an additional three days and 15 hours1.736111e-4 days <br />0.00417 hours <br />2.480159e-5 weeks <br />5.7075e-6 months <br />.

11. Since there is ' no feasible means of causing - the ' atmospheric pressure inside of the fuel handling building to be significantly greater .than a

normal. the maximum anticipated water temperature is 212 degrees F and-

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therefore the maximum anticipated fuel cladding temperature is expected to be within the 200 to 300 degree F range. The zirconium-water reaction would

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not be expected to be significant at temperatures less than 1800 degrees F.

Thus, the anticipated fuel cladding temperature of 200 to 300 degrees F. is considerably lower tisan the temperature necessary for a significant1 amount of zirconium-water reaction to occur.

12. The spent fuel pool cooling system consists of one heat exchanger with' two pumps and associated valves and piping. Ona pump is normally operating with the second pump as a spare in the event that the first pump is not available. This cooling system is not _ seismic Category.. I, safety-related at this time. The Licensee has committed to upgrading the cooling system such that it will remain functional after a safe shutdown earthquake.

When the upgrading is complete, the spent fuel pool cooling system will meet the pidelines of Regulatory Guide 1.29, Position C.1, which addresses the design of safety-related structures, systems and components with respect to their ability to withstand the safe shutdown earthquake and to remain operational. By meeting this Position , the Licensee _ complies with the requirements of General Design Criterion 2 of 10 CFR Part 50, Appendix A,

" Design Bases for Protection Against Natural Phenomena," for protection-against earthquakes.

13. The Licensee has evaluated the radiological effects of boiling in the -

spent fuel pool. The Staff has performed an independent accident evaluation of the offsite radiological consequences and has found the consequences _ to be a small fraction of the 10 CFR 100 guidelines. See Affidavit of Millard Wohl on Contention 4. Based on the small radiological consequences as the result of the pool boiling, the ability to take the single active failure of the spent fuel pool cooling pump, and the low probability of having an

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B earthquake until the cooling system is upgraded to safety related, the Staff concludes that the design meets the guidelines of Regulatory Guide 1.29, Position C.2, which addresses the seismic aspects of non-safety related equipment. Therefore, the Licensee meets the requirements of General Design Criterion 2 of 10 CFR Part 50, Appendix A.

14 . . In summary, although the normal maximum pool water temperature of 140.8 degrees F is slightly higher than the guidance identified in the SRP, the pool water temperature is acceptable because it is based on conservative assumptions regarding core discharge and the temperature only exceeds the 140 degree F temperature for a short period of time. In addition, if there were a loss of cooling to the spent fuel pool, the fuel cladding temperature will not increase to the temperature necessary for_ a significant amount of zirconium-water reaction to occur and there is adequate i

time for providing make up water to the pool to prevent spent fuel pool boiling.

The foregoing and the attached statement of professional qualifications are true and correct to the best of my knowledge and belief.

> 1 s ohn N. Ridgely Subscribed and sworn to before me this /gd day of February,1986 Notary Public j 1

My ccmmission expires: 7 [f4

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.t' envi r onmer. t al'. ' analysis ~and'. reviewing ~ applications _for operating li-

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conses,. proposed technical specifications, and' spent fuel pool-expan ,

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sions. Todate. . I. have revi ewed the design. of the -spent f uel storage facilities for- 11 reactor sites and have performed ~the' analytical-review for sin additional facilities.- This represents 21 spent. fuel storage facilities, r

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PROFESSIONAL QUALIFICATIONS JOHN N. RIDGELY PLANT SYSTEMS BRANCH DIVISION OF BWR LICENSING _

I am employed as a Mechanical Engineer (Auxiliary Systems) in the Plant Systems Branch, Division of BWR Licensing, Office of Nuclear Reactor Regulation, United States Nuc1 car Regulatory Commission, Washington, D.C. My duties consist of reviewing and evaluating the essociated safety consideration on nuclear power and fuel handling cystems and associated engineering ficids on power reactors. I am responsible for providing technical input to various documents includ-ing Safety Evaluation Reports.

I attended the Virginia Polytechnic Institute in Blacksburg, Virginia and received a B.S. degree in Nuclear Science in 1972.

In July of 1972 I joined the Philadelphia Electric Company's Mechanical Engineering Division as a mechanical engineer.

'At the Philadelphia Electric Company, I worked with both fossil and nuclear power plants. I designed systems, prepared specifica-tions, performed computer analysis, and managed contracts. During this time I developed and had patented a process for removing tritium from High Temperature Gas Cooled Reactors. I wrote purchase order l cpecifications for high density spent fuel storage racks for Peach Bottom Atomic Power Station, reviewed the bids, awarded the contract, cnd performed a field audit at the manufacturer's facility. I also performed the preliminary work for the high density spent fuel storage racks for Limerick Generating Station.

From August 1977 through November 1980, I was employed by the Potomac Electric Power Company in Washington, D.C., as a mechanical engineer. During this time, I worked exclusively with fossil power plants. My duties in this position were similar to those at Philadelphia Electric Company. In addition, I have design water treatment subsystems and assisted in other system designs including water intake and discharge treatment systems.

From December 1980 to the present, I have been employed by the United States Nuclear Regulatory Commission. I have been in the Auxiliary Systems Branch of the Division of Systems Integration until November 24, 1995 when NRR was reorgani cd and I have been assigned to the Plants Systems Branch, Division of BWR Licensing. I have revised portions of the Standard Review Plan and have been the Task Manager for the resolution of two Gencric Issues. My duties include safety revi ews and evaluations of system design and operation at nuclear power plant facilities. As required, I prepare safety evalua-tions .and make presentations to the Advisory Committee on Reactor Safeguards. I am presently managing a contract for subcompartment 1