ML20137W850

Affidavit of LI Kopp Supporting Licensee 860123 Motion for Summary Disposition of Contention 3 Re Increased Fuel Enrichment

ML20137W850
Person / Time
Site:	Turkey Point
Issue date:	02/18/1986
From:	Kopp L Office of Nuclear Reactor Regulation
To:
Shared Package
ML20137W848	List: ML20137W842 ML20137W850 ML20137W856
References
OLA-3, NUDOCS 8602200388
Download: ML20137W850 (7)

Text

.- _ . _ _ . _ -

, WIT TrATES OF AhERICA WCLEAR RBOUIA'IWY 03fdISSIN BERFI 'll!E ATWIC SAFEIY AND LIONSING BOARD In the Matter of )

) Docket Nos. 50-250 OIA-3 FI0lIDA PGUt & LIOff Q1PANY ) 50-251 GA-3

) (Increased Fuel Enric! nent)

('Ibrkey Point Plant , thits 3 and 4) )

AFFIIMVIT OF IALP.ENCE I.10PP RBGARDl!K) OtW11Nrim 3 I, Laurence I. Kopp, being duly sworn state:

1. I am a Nuc! car Engineer in the Reactor Systems Branch of the Division of PWR Licensing-B in the Office of Nuclear Reactor Regulation, U.S. Nuclear Regulatory Commission. I was responsible for the Staff's review of the criticality analysis of the existing spent fuel and new fuel storage in the Turkey Point Unit 3 and 4 fuel storage facilities, as reflected in the Staff's Safety Evaluation dated September 5, 1984. A summary of my professional qualifications and experience is attached.

2. The purpose of this Affidavit is to addresa Contention 3, which states as follows:

CONTENTION 3. That the uranium enrichment amendments <

increase the chances of a criticality accident occurring in the fresh fuel pool and establishes a clear reduction in the safety margin of the fresh and spent fuel pool.

3. The Licensing Board stated on page 7 of its Memorandum and Order of September 24, 1985, that Contention 3 "should be read as i

challenging the adequacy of this acceptance criteria by alleging that k,gg l

of 0.98 is not adequately safe for fresh fuel exposed to abnormal, j opthaum moderation conditions and 0.05 is not adequate for fresh or s

{

0

s spent fuel, exposed to the abnormal condition of full flooding with unborated water." This Affidavit will, therefore, address the Staff's acceptance criteria for preventing criticality in fresh fuel storage racks and in spent fuel pools, and the adequacy of those criteria.

4. I have read the " Licensee's Motion for Summary Disposition of Contention 3," and the " Licensee's Statement of Material Facts As To Which There Is No Genuine issue To Be Heard With Respect to Contention 3 " dated January 23, 1986, and the "Aff1 davit of Dr. Stanley E. Turner on Contention No. 3 " dated January 17, 1986 The material facts stated by Licensee in relation to Contention 3 are correct and I concur in the conclusions reached in the supporting affidavit of Dr. Turner.

5. General Design Criterion (GDC) 62 of Appendix A to 10 CFR Part 50 of the Nuclear Rerulatory Commission regulations states that

" Criticality in the fuel storage and Sandling system shall be prevented by physical systems or processes, preferably by une of geometrically safe configurations." Criticality occurs when keff (neutron multiplication factor) is equal to or greater than unity.

6. For fresh fuel storage areas, the fuel is normally stored in a dry condition since unieradiated fuel contains no radioactive fission products and, therefore, requiren no shielding or cooling, in this normal configuration, and with the absence of moderation, the it,gg of the fresh fuel array is typically less than 0.70 (over 30% subcritical).

7. Although fresh fuel in normally stored

• in this dry configuration , the Staff requires the criticality analyses performed by licensees to consider flooding of the fresh fuel storage areas with

4 pure unborated water ranging in density from 1.0 gm/cc to very low hypothetical values (0.2 to 0.05 gm/cc), unless the dry storage facility I has been designed to prevent these flooding conditions. The water density which results in the maximum value of k eff is usually called the

" optimum moderation" condition. ,

8. NRC's acceptance criteria for criticality of new (fresh) fuel i storage is found in Standard Review Plan (SRP) Section 9.1.1 (NUREG-0800). Section 9.1.1 requires that the storage racks be

! designed so that k,gg for the racks fully loaded with fuel of the highest anticipated enrichment and fully flooded with pure (unborated) water is less than about 0.95. SRp Section 9.1.1 also requires that the fresh fuel storage racks be designed so that k,gg for the racks fully loaded with fuel of the highest anticipated enrichment, and assuming optimum i moderation, that is , fog, mist or foam, be no greater than 0.98. It should be noted that in some designs, the fully flooded condition may also be the optimum moderation condition (i.e., yield the highest keff)

• However, in such a case, the Staff requires the more restrictive k,gg criterion of 0.95 to be met.

l 9. With respect to the low-density, optimum moderation 4

assumption, the water density required for the maximum k,gg is a very

narrow range. It is inconceivable that one could obtain this precise l area; optimum density uniformly throughout the entire storage i '

l Therefore, the k ggg criterion for optimum moderation (0.98) establishes a j conservative upper bound with the assurance that any realistically possible

.)

accident condition will be lower.

i I

10. For spent (irradiated) fuel storage, the fuel is normally stored in a pool flooded with water to provide shleiding and cooling. For pressurized water reactor storage facilities, the pool water is maintained with a large concentration of soluble boron which acts as a neutron poison and resulto in a k,gg typically less than 0.75 (over 25%

suberitical) . Although spent fuel is normally stored in this borated water configuration. the Staff requires the criticality analysis performed by the Licensee to assume a fully flooded unborated condition.

11. tiRC's acceptance criteria for criticality of spent fuel storage is found in SRP Section 9.1.2, which requires that the storage racks be designed so that k,fg for the racks fully loaded with spent fuel and fully flooded with nonborated water be no greater than 0.95.

12. The calculated value of k,ff for the above-mentioned accident conditions of flooding of the normally dry fresh fuel storage racks, or assuming the absence of boron in the spent fuel pool water, requires inclusion of all known uncertainties. These encompass uncertainties in the calculational methods as well as uncertainties due to variations in the mechanical and material specifications from their nominal values. Two r.icthods are acceptable for determining these uncertainties, in the first method , k,gg is calculated for worst case mechanical and material conditions chosen to maximize k,gg. In the second method, the analysis of the storage racks is performed on the basis of nominal material and mechanical specifications. Then n sensitivity study is performed which includes all possible significant variations in the material and mechanical specifications of the racks. This sensitivity study is then used to determine the uncertainty in keff f r motorial and mechanical variations

from nominal rack specifications. Combinations of the two methods may l

also be used. These uncertainties are always accounted for in the most l adverse direction, thereby yielding a conservatively high value of the calculated k eff. Additional confidence is provided by the soluble poison I

(boron) normally present in the spent fuel water.

13. With specific reference to the enrichment increase of Turkey Point Units 3 and 4, the following should be noted. Subsequent to the issuing of the license for the existing fresh fuel storage facility, the NRC Staff identified the low-density optimum moderation conditions mentioned previously in this Affidavit. The Staff thereafter established l

the k ggf criterion of 0.98 for these conditions and required all now applications or amendments relating to the storage of , fresh fuel to l analyze for optimum moderation conditions , to meet the acceptance criterion of k ggg 0.98, and to provide apptopriate technical specifica-tions. Therefore, with the request for an enrichment increase at l Turkey Point, an additional requirement was imposed on the Licensee by requiring an analysis at optimum moderation conditions and including the new criterion of 0.08 in the Technical Specifications. The Staff l considers this to be an additional requirement over the original license requirements, for newly-identified conditions, and does not constitute an increase in the limiting criterlon to prevent criticality for the fully flooded condition previously evaluated. The increased fuel enrichment at Turkey Point did not change the previous limiting critorion of kggg less than 0.95 for all other normal and accident conditions in both the fresh

^

fuel storage aren and the spent fuel pool. Thus, the margin of safety for conditions previounty considered is not reduced.

l i

In conclusion, based on the above, the Staff's limiting criteria on fresh fuel and spent fuel storage as set forth in SRP Sections 9.1.1 and 9.1.2 provide an adequate margin of suberiticality to ensure that GDC 62 is met and criticality is prevented at Turkey Point. Moreover, the new restriction of k,ff of 0.98 for optimum moderation conditions does not increase the chances of criticality occurring in the fresh fuel pool, nor does the amendment establish any reduction in the safety margin of the fresh and spent fuel pool. Accordingly, summary disposition should be granted with respect to Contention 3.

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

Anna y

'Laurence 1. Kopp //

Subscribed and sworn to before me this g day of February,1986.

/

otary Public My commission expires: *)///g6 I I e__

)

\'

i

! STATEf,IE!!T OF PROFESSIONAL QUALIFICATIO?!S OF DR. LAURE? ICE I. KOPP i

A l Education: Fairleigh Dickinson University B.S. Physics,1956 i Stevens Institute of Technology, M.S. Physics,1959 University of Pfaryland, Ph.D. , Nuclear Engineering,1968 Professional Experience: U.S. Nuclear Regulatory Commission j fluclear Engineer (1965 - Present)

Safety evaluations of reactor core design as described in applications for Construction Permits and Operating Licenses, topical reports submitted by reactor vendors and licensees on safety-related subjects, criticality analyses of fresh and spent fuel storage racks.

1 Westinghouse Astronuclear Laboratory Senior Scientist (1903 - 1965) i Design and analyses of reactor physics aspects of nuclear i

propulsion systems related to NERVA program including i development of computer programs.

flartin-Picrietta Corporation Senior Engineer (1959 - 1963)

Design and analyses of reactor physics aspects of advanced concept reactors such as the fluidized bed and compact space reactors. Development of analytical methods and computer codes for nuclear reactor design j and analysis.

Federal Electric Corporation Senior Programmer (1957 - 1959)

]

Developed and programmed various computer codes for

DEWLI?!E project including payro!!, statistical analysis of failure rates, and inventory control,

)

l; Curtiss Wright Hescarch Division l Physicist (1956 - 1957)

Assisted in development and programming of reactor j analysis methods.

i a

l I

j

-