ML20153D204

Affidavit of B Turovlin Supporting Util 860123 Motion for Summary Disposition of Contention 6 Re Matls Integrity

ML20153D204
Person / Time
Site:	Turkey Point
Issue date:	02/18/1986
From:	Turovlin B Office of Nuclear Reactor Regulation
To:
Shared Package
ML17342A383	List: ML20153D082 ML20153D108 ML20153D150 ML20153D172 ML20153D204 ML20153D244 ML20153D252
References
OLA-2, NUDOCS 8602240043
Download: ML20153D204 (10)

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. UNITED STATES OF AMERICA

. NUCLEAR REGULATORY. COMMISSION-i BEFORE TIIE ATOMIC SAFETY AND LICENSING: BOARD 1-l y 'In the Matter of ) .

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) Docket Nos. 50-250 OLA-2 1 1 FLORIDA POWER & LIGHT COMPANY ) 50-251 OLA-2 i )

l- (Turkey Point Plant, Units 3 and 4) ) (SFP Expansion) '

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j, AFFIDAVIT OF BERNARD TUROVLIN ON CONTENTION 6 1

I, Bernard Turovlin, being duly sworn, state as follows:

1. I an employed by the U.S. Nuclear Regulatory Commission as a ' , ,

i Material Engineer in the Engineering Branch of the Office of Nuclear Reactor-j Regulation. Prior to November 24, 1985, I .was a Chemical Engineer in the f Chemical and Corrosion Technology Section, Chemical Engineering Branch, I

Division of Engineering. A copy of my professional qualifications is attached.

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2. The purpose of my affidavit is to. address . Contention 6, with f' respect to any potential for loss of material integrity 'due to the increased i

j fuel storage capacity and the longer term storage of some fuel elements. With l

regard to Contention 6, I have read " Licensee's . Motion for Summary i

l Disposition of Intervenors' Contentions" and " Licensee's Statement of Material

! Facts as to Which There Is No Genuine Issue T6 Be Heard With Respect to

} Intervenors' Contentions," dated January 23,-1986. The material facts stated i

j in relation to Contention 6 are correct and I concur.in the conclusions '

{ reached in .the supporting affidavits. Contention 6 and the bases for the.

contentions state as follows:

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Contention 6 The Licensee and Staff have not adequately considered or analyzed materials deterioration 'or failure in materials . integrity.

. resulting from the increased generation and heat and ' radio-I activity, as a result of increased capacity and long term storago, in the spent fuel pool.

.i Bases for Contention The spent fuel facility at Turkey Point was originally designed to .

! store a lesser amount of fuel for a short period of time. Some of the problems that have not been analyzed properly are:

(a) deterioration of fuel cladding as a result of increased exposure and decay heat and radiation levels during extended periods of pool storage.

(b) loss of materials integrity of storage rack and pool liner as a result of exposure to higher levels of radiation over longer periods.

(c) deterioration of concrete pool structure as a result of exposure to increased heat over extended periods of time.

, 3. The materials that can be affected by increased . storage capacity and extended time in storage of fuel elements are the fuel pin (or rod) cladding, fuel element materials other than cladding, storage rack materials, storage pool liner, and storage pool concrete structure.

4. Redesign of the spent fuel pool racks increases only the storage capacity of the pool and not the frequency or the amount of newly discharged fuel to be placed in the pool during each fuel reload cycle. The rerack i

design does not change the radioactivity of the newly discharged fuel placed in the storage pool. Before the current amendments authorizing the increased storage capacity of the Turkey Point spent fuel pools of 1404 cells, the authorized storage capacity of Units 3 and 4 was 636 elements. Each unit had a usable storage capacity of only 621 and 614 fuel elements, respectively,

r due to piping and other futerference. Based upon the estimated number of fuel elements to be discharged in future refuelings, the storage capacity would not have been exceeded until after the Cycle 13 refueling in December 1989 and December 1988 for Units 3 and 4, respectively. The oldest discharged elements, which in other circumstances would have been sent away for reprocessing will, in 1988 for Unit 4 and 1989 for Unit 3, be i stored in the expanded capacity. These first reload discharged elements will i

have by then aged in the pool for at least 13.5 years and the radiation and thermal output from these elements will have decreased to minor levels. This rerack allows the storage of an additional 780 elements all of which will have been in residence in the storage pool for at least 13.5 years.

5. Fuel elements stored over 13.5 years contribute little to the heat load of the spent fuel storage pool. These elements cause an increase in maximum pool temperature of approximately 1 to 2 degrees when newly discharged fuel is added to the pool. As these old elements continue to age, they contribute less and less to the heat load of the pool. The heat load contribution of all the aged elements during the last 10 refuelings (calculated by Westinghouse) only raises the maximum pool temperature after refueling to 143cF and decreases thereafter. This maximum pool temperature is within NRC guidelines.

6. As calculated by Westinghouse, the materials in the spent fuel pool 13 can be expected to be exposed to a maximum neutron fluence of 4.8 x 10 0

neutrons /cm and 1.9 x 10 rads of gamma radiation. Of the materials in the spent fuel pool, only the first discharged elements can be expected to receive this amount of radiation. The pool liner and pool concrete structure i

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I while in place in the pool for the entire ' storage period will have the radiation -

i. attenuated by distance from the radiation sources (the aged elements) and the

j. shielding afforded by the water. The fuel element racks which are new will i

have the shortest residence in the pool of ' all .the materials. except newly i

discharged fuel. 1 l 7. The new ~ spent fuel storage racks are constructed of Type 304 1

j stainless steel as the load carrying structure and use sheets'of Boraflex (held.

i i in place by.a thin-walled stainless steel wrapper) on the outer surface of the

} storage cells and between the cells as a neutron absorbing material. Type i l 304 stainless steel is also used in fuel element hardware and the pool liner.

Other metallic materials in the storage pool are Inconel and Zircaloy parts of  !

l the fuel element assemblies. The pool structure is concrete composed of ASTM C-150 type II cement and aggregate meeting the requirements of ASTM i

j C33 and reinforcing bars of ASTM A-15 steel.

l 8. Stainless steel clad fuel elements have been stored in PWR ~ spent i fuel pools more than 18 years. This represents the maximum exposure any i

j stainless steel can accumulate in a spent fuel pool since the steel is directly

against the fuel as the cladding material. Destructive and visual examination i

of this material produced no evidence of significant degradation of the

, stainless steel. Zirealoy-clad rods were examined after nearly 21 years of

{ water storage. A comparison of cladding properties with those measured 20 I

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years earlier on rods from the same fuel assembly showed that no detectable f changes had occurred in corrosion film thickness , cladding mechanical  ;

properties and fission gas release. Zircaloy-clad fuel elements which had i

i been charged into Canada's NPD reactor in 1962 are continuing to operate i

satisfactorily (i.e., with no apparent degradation) after 22 years of exposure to far greater radiation than any element in the Turkey Point spent fuel pools will .reccive during residence in the pools. W.J. Bailey, N.B . Johnson , Jr.

et al . , Surveillance of Spent Fuel in Wet Storage. NP-3765 October 1984 Electric Power Research Institute.

9. Irradiated fuel has been discharged into water pools since the first irradiated fuel was discharged from the Oak Ridge X-10 reactor into its pool in November 1943. Spent commercial fuel is presently stored in water-filled concrete pools that are lined with stainless steel. Some of these pools have been in use for more than 25 years. During this extended storage time there has not been any evidence of the degradation of the concrete structure of any of the spent fuel pools. In addition to the excellent performance of the concrete in the spent fuel pools, the dismantling of many concrete structures i

used as shielding, has not produced any evidence of degradation due to radiation heating or radiation.

10. In granting the previous rerack amendments for Turkey Point, the Staff approved the use of concrete -- as well as stainless steel in the pool liner, rack lattice structure and fuel storage cells -- until the end of the life of the plant. The NRC issued a Safety Evaluation (SE), dated November 21, 1984, which addressed the materials compatibility and corrosion degradation 1 aspects of the current spent fuel pool modifications (i .e . , reracking) and

' concluded that the Licensee complies with General Design Criteria 61 and 62 of 10 CFR Part 50, Appendix A. This conclusion was supported by finding that the environmental compatibility and stability of the materials used in the expanded spent fuel pools is adequate based on test data and actual

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experience in operating reactors and that Licensee has adopted an acceptable pool materials surveillance program. The only materials used in the s

modifications that had not been previously approved were the' Boraflex nuclear absorber strips. Boraflex, has undergone extensive testing to study the effects of gamma irradiation in various environments and to verify its

! l l structural integrity and suitability as a neutron absorbing material. The tests show that Boraflex maintains its neutron attenuation capabilities after i

being subjected to gamma radiation. Tests also show that Doraflex is

- unaffected by the pool water environment and will not be degraded by j corrosion. To provide added assurance that no unexpected corrosion or I degradation of the integrity of the racks, the Licensee committed to conduct a f long term materials surveillance program. The Staff reviewed the Licensee's material surveillance program and found that the program provided reasonable assurance that the Boraflex material will be monitored so that the Boraflex will perform its function for the life of the _ plant. SE Section 2.2.

11. Because materials degradation in the spent fuel pool, either from i

i radiation effects or corrosion is a long term effect, (C. Czajkowski, J.R.

j Weeks, and S.R. Protter. " Corrosion of Structural and Poison Material in

, Spent Fuel Storage Pools ," CORROSION /81, Paper 163, Toronto , Ontario, j Canada, April 6-10, 1981. National Association of Corrosion Engineers), the Staff's position regarding spent fuel modification requires that pool modifications include a long term material surveillance program. Since 1978 all i spent fuel pool modifications that have included the use of poison material to 7

control criticality have been required to have a material surveillance program or its equivalent. "OT Position for Review and Acceptance of Spent Fuel i

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Storage and Handling Applications," dated April 14, 1978. Many of the pools have used stainless steel and Boraflex. While the materials in these surveillance programs are not identical (i.e., not processed at the same time) they are similar to the extent that degradation information can be used to evaluate the behavior of the Turkey Point material. Experience with these leading ongoing surveillance programs has provided many hours of spent fuel pool exposure without significant degradation of the materials.

12. Experience world wide with stored fuel has shown (Technical Report Series No. 218: " Storage of Water Reactor Spent Fuel in Water Pools -

Survey of World Experience," International Atomic Energy Agency, Vienna, Austria , 1982) and the Commission concluded in its " Waste Confidence Decision," dated August 22, 1984 (49 Fed. Reg. 3458, August 31,1984), that spent fuel can be stored safely--either at reactor sites or at independent installations--for up to 30 years beyond the expiration of reactor operating licenses without significant degradation.

13. As noted in the recent International Atomic Energy Agency world survey cited above, the 40 years of positive experience with wet storage illustrates that it is a fully-developed technology with no associated major technological problems . Spent fuel storage pools are operated without significant risk to the public or the plant personnel. There is substantial technical basis for allowing spent fuel to remain in wet storage for several decades. There continues to ha no evidence that Zircaloy-clad fuel degrades significantly during wet storage -- this includes: continuous storage of fuel elements for as many as 25 years and irradiation of fuel in reactors for as long as 22 years. Cladding defects have had little impact during wet i

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<3 storage. Experience to date with handling operations at spent fuel storage i

pools indicates that failed fuel rods can be accommodated e Very few fuel o e assemblies have suffered major mechanical danIage as aer'sult of handling operations at spent fuel storage pools, s r

14. In summary, the materials in the spent fuel pools will not degrade significantly because of the increased pool storage capacity or the storage of elements longer than 13.5 years. The stainless steel storage racks which are

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yew will not be degraded because of increased radiation by agad fuel elements. The contribution of radiation to the adjacent structure decreases Y w as the elements age. The Staff evaluated the use of stainless steels in ,

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storage racks in approving the prior. Turkey Point' rerack amendments and concluded that the stainless steel racks could be used to the end of life of the plant. Many experiments have shown that stainless, as well as the Inconel and Zircaloy in the aged fuel elements, can be exposed to many orders of magnitude of radiation greater than can be reasonably expected at thie rack structure without significant degradation. In addition, there is no evidence of degradation due to rbdiation or heat of storage pool liners or concrete structure in spent fuel pools world wide. While the Staff guidelines suggest a maximum pool water temperature of 1400 F after normal discharge, any of the materials in the pool can .be exposed to much hi'gher temperatures 1

(145o F to 1800 F) for extended periods without detectable degradation. -

Accordingly, the Staff ha$ adeouately considered and analyzed degradation in materials integrity resulting from increased generation of heat an$ f, radioactivity, as a result of the increased capacity and the extended storage time of aged fuel elements in the Turkey Point spent fuel pools.

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

Bernard Turo~vlin Suscribed and sworn to before me this Li, day of February,1986 k(??)

Notary Public k

My commission expires: y///76 1

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,9 PROFESSIONAL QUALIFICATIONS BERNARD 'rUROVLIN >

PROFESSIONAL ENGINEER - CALIFORNIA #9180 MAY 1949 I am employed by the U.S. Nuclear Regulatory Commission as a Materials Engineer in the Engineer Branch Office of Nuclear Reactor Regulation.

Prior to November 24, 1985, I was a Corrosion Engineer in the Chemical Engineering Branch of the Office . of Nuclear Reactor Regulation. I am responsible for safety review and evaluation of the degradation of materials used in the construction and operation of nuclear power plants. ,

I received a Bachelor of Science degree from the University of Illinois in 1941.

I have been associated with nuclear energy development and construction as an engineer or metallurgist since 1942. I have been employed in these capacities by the f.fetallurgical Laboratory of the University of Chicago, the Los Alamos Laboratory, the Brookhaven National Laboratory, Combus-tion Engineering Inc., General Atomic, General Dynamics /Convair, and the U.S. Army Nuclear Power Group. I have spent a minimum of 4 years at each location.

I have been responsible for the development of basic fabrication techniques, non-destructive examination, and failure analysis. I have done engineering design and component testing for various components used in the nuclear energy field.

I have more than 15 patents for various components and techniques used in the above field, i

I have published more than a dozen papere related to this field. '