ML20238A075

Testimony of Ew Thomas on Contention 6.* Testimony of Ew Thomas on Contention 6 Re Matl Deterioration or Failure in Matls Integrity of Spent Fuel Pool Liner & Concrete Pool Structure Due to Heat.Related Correspondence

ML20238A075
Person / Time
Site:	Turkey Point
Issue date:	08/31/1987
From:	Eric Thomas BECHTEL GROUP, INC.
To:
Shared Package
ML20237L743	List: ML20237L739 ML20237L816 ML20238A021 ML20238A042 ML20238A075 ML20238A130 ML20238A236 ML20238A273
References
OLA-2, NUDOCS 8709090122
Download: ML20238A075 (14)

Text

- -__ _ _ - _ _ - -

i i

<J y _-

l' 2

UNITED STATES OF AMERICA 3

NUCLEAR REGULATORY COMMISSION 4.

BEFORE THE ATOMIC SAFETY AND LICENSING BOARD 5

6 In the Matter of

) Docket Nos. 50-250-OLA-2 7

)

50-251-OLA-2 FLORIDA. POWER & LIGHT COMPANY

)

8 (Turkey Point Nuclear Generating )

Station, Units 3 & 4)-

) (Spent Fuel Pool Expansion) 9 10, Testimony of Eugene W. Thomas On Contention Number 6 11 Ql:

Please state your name and address.

12 A1:

My name is Eugene W. Thomas.

I am employed by Bechtel 13 Eastern Power Corporation as Assistant Chief Civil 14 Engineer.

My mailing address is 15740-Shady Grove Road, 15 Gaithersburg, Maryland 20877.

16 Q2:

Please describe your professional qualifications and 17 experience.

18 A2:

A summary of my professional qualifications and 19-experience is attached as Exhibit A and is incorporated 20 herein by reference.

21 Q3:

What is the purpose of your testimony?

22 A3:

The purpose of my testimony is to address Contention 6.

23 Contention 6 and the bases for that contention are as 24 follows:

25 Contention 6 26 The Licensee and Staff have not 27 adequately considered or analyzed materials deterioration or failure in 28 8709090122 070831 PDR ADOCK 05000250 0

PDR

-g-1 2

materials integrity resulting from the increased generation heat and 3

radioactivity, as a result of increased capacity and long-term storage, in the 4

spent-fuel pool.

5 Bases for Contention l

6 The spent fuel facility at Turkey Point was originally designed to store a lesser 1

7 amount of fuel for a short period of time.

Some of the problems that have not 8

been analyzed properly are:

9 (a) deterioration of fuel cladding as a result of increased exposure and 10 decay heat and radiation levels during extended periods of pool 11 storage.

12 (b) loss of materials integrity of storage rack and pool liner as a 13 result of exposure to higher levels of radiation over longer periods.

14 (c) deterioration of concrete pool 15 structure as a result of exposure to increased heat over extended periods 16 of time.

17 Specifically, the purpose of my testimony is to address 18 material deterioration or failure in materials integrity-19 of the spent fuel pool liner and concrete pool structure 20 due to heat from the increased capacity of the Turkey 21 Point spent fuel pools.

Other issues raised by 22 Contention 6 are addressed in the Testimony of William 23 C. Hopkins on Contention Number 6 (materials 24 deterioration or failure in materials integrity of the 25 liner and concrete pool structure due to radiation), the 26 Testimony of Dr. Gerald R.

Kilp and Russell Gouldy on 27 Contention Number 6 (materials deterioration or failure 28

3'-~

s r

L1

- 2l J

in materials integrity of the fuel assemblies and 3-

. storage' racks), and the Testimony of William A. Boyd on 4

Contention Number 6 (impact'on K-effective of postulated 5'

gapsfin the.Boraflex plates in the Turkey Point' spent 6.

fuel storage.. racks).

7'

'Q4:.Please describe the' Turkey Point spent fuel pool 8-

' concrete structure and liner.

9 A4:

The spent' fuel; pool structure is rectangular in shape 10 -'

with'inside dimensions of 25'-4" by 41'-4" and'with a 11 height of approximately140 feet.

A four foot, thick 12 cross wallion one end of the prol separat'es the storage 13 area from the refueling canal.

The walls'and floor are 14 constructed of reinforced concrete with a 1/4" thick i

15 stainless steel liner' plate system covering-the entire 16 inside surface of the pool.

With the exception of.a 17 three foot length of wall on either side of the

.18 refueling canal which is'18" thick, the walls range from 19

'3'-0" to 5'-6"' thick.

The floor of the pool,~which also 20 serves as a base ~ mat at grade, ranges in thickness from 21 3' to 4'-6".

22 The spent fuel pool liner plate is' ASTM (American 23 Society for Testing and Materials) A-240 Type 304 24 stainless. steel.

Stainless steel shapes and bar are 25 ASTM A-276 or A-479 (Type 304) or AISI (American Irc 26 and Steel Insi.itute) Type 302 or 304.

Stiffeners and 27 anchorage attachments for embedments (studs and threaded 28 rods) are ASTM A-36.

Concrete is manufactured in I

l. -

+

'l i

2 accordance with ACI (American Concrete Institute) 301.

I 3

The main constituents of the concrete are ASTM C-150 i

4 Type II cement and aggregate meeting the requirements of 5

ASTM C-33. Reinforcing steel is ASTM A-15, intermediate

'6 grade.

7 05:

What issues would the_ generation of heat in the spent 8

fuel pool raise regarding the integrity of the concrete 9

pool structure and' liner?

10 A5:

Two issues would be raised.

The first issue pertains to t

11 the thermal stresses induced in the structure as a 12 result of the. temperature differential between the pool 13 water and ambient conditions, and the second pertains to-14 materials integrity.

15 06:

Did you perform an analysis of the thermal stresses on 16 the concrete pool structure?

17 A6:

Yes.

The load carrying capacity of the pool structure 18 was evaluated by conducting a detailed computer analysis 19 as part of the overall evaluation of the pool for 20 increased capacity.

Using the ANSYS program, which is a j

21 public domain, industry recognized standard structural 1

22 analysis technique, the pool structure was mathematic-

23 ally modeled as a large number of solid finite elements 24 with sufficient detail to accurately capture response to 25 load.

All loads imposed on the structure were 26 considered, including the effect of heat from the pool i

27 water as well as all postulated extreme environmental 28

'l 2

conditions, as addressed in the original licensing 3

documents.

There_may also be nuclear heating of the 4

concrete ~and steel as a result of radiation.

Nuclear 5

heating has the same mechanical effect on the concrete 6

structures.and liner plate as thermal heating.

As 7

discussed in the Testimony of William C. Hopk' ins on 8

Contention. Number 6, the magnitude of nuclear heating is i

9 insignificant as compared with thermal heating caused by

/

10 the temperature of the pool water.

11 Thermal effects were not=a specific concern since

.j 12 the increased. capacity of the pool results in only minor 13 variations from the original design condition, but were included to provide an entire load identification of the l

14 15-structure.. Water temperatures in the pool for the 16 operating, abnormal and postulated boiling conditions 17 0

(212 F) were considered.

Since the most severe loads

_.18 on the structure due to heat are caused by temperature 19 gradients (i.e., large temperature differences on 20 opposite sides of the pool walls), the ambient 21 temperature outside the pool was assumed to be as low as 22 0

30 F,

resulting in a gradient of as much as 182 F

23 through the wall thickness for analytical purposes.

24 The 30 F temperature specified on the outside 25 surface of the pool is extremely conservative for the 26 site environment of Southern Florida.

A review of 33 27 years of meteorological records for that area indicated 28 1.

i 1

2 that the lowest mean five' consecutive days temperature 3

was 48 F.

Thermal conductivity analysis shows that for 4

a three foot thick wall, a steady state temperature 5

gradient condition for the worst postulated temperatures 6

would take five days to develop.

The review of the 33

'7 years of records also indicated that the lowest recorded 8

temperature was 31 F, which lasted only three hours.

9 Using methods addressed in ACI Committee 349 j

10 report, " Criteria for Reinforced Concrete Nuclear l

11 Containment Structure," ACI Journal, January 1972, the

)

12 loads from the computer analysis were converted into 13 reinforcing steel and concrete stresses at various 14 critical locations on each of the walls and the floor.

15 These stresses were shown to be within the licensing 16 condition imposed on the original design as identified 17 in the Turkey Point Units 3 and 4,

" Updated Final Safety 18 Analysis Report," Docket Nos. 50-250 and 50-251, 19 Appendix SA.

Further, the analysis shows that the pool 20 maintains its structural integrity even under severe 21 conditions of postulated boiling water combined with the 22 effects of the design basis earthquake.

23 07:

Did you evaluate thermal stresses on the spent fuel pool 24 liner plate?

25 A7:

Yes.

The liner plate was conservatively not considered 26 to provide structural capability in the structural 27 analysis of the pool concrete structure.

However, a 28

___-_____ ______ - _ _ ' =

l 1

.c 2

separate analysis was conducted to determine the effects i

3.

of thermal, hydrostatic and hydrodynamic loads on the 4

' functionality of the liner plate system.

This analysis 5

reviewed the buckling potential of the. liner plate, as 6-well'as stresses-in welds and embedded metal associated 7

with the liner system.

The analysis showed that there j

8 would be no_ loss of function under all postulated l

9 conditions.

10 08:.

Do you have a conclusion with respect to thermal 11 stresses on the' concrete pool structure and the liner 12 plate?

13 A8:

Yes'.

The pool was analyzed considering the thermal and 14 mechanical effects of the increased spent fuel capacity 15 for normal, abnormal and postulated boiling water 16 conditions, in conjunction with postulated accident 17 conditions as specified in the Updated Final Safety 18 Analysis Report.

The results of the analysis 19 demonstrate that the pool structure and liner plate meet 20 the original licensing acceptance conditions and 21 maintain their structural integrity under all of these 22 conditions.

23 09:

Was the effect of temperature on the integrity of the 24 Turkey Point concrete pool structures and liner plates 25 considered during the initial design process?

26 27 28

l 1

l 2

A9:

Yes.

The thermal environment was takri into 3

consideration in the selection of materials during the a

4

. initial design process.

The increased capacity of the i

5 pool does not raise a new issue regarding deterioration 1

6 of the concrete pool structure, including the liner l

7 plate, as a result of exposure to increased temperatures 8

over. extended periods of time.

9 Q10:

Please describe the effect of temperature on the 10 stainless steel in the liner plate.

11 A10:

Stainless steel was chosen for the liner plate because 12 of its demonstrated ability to perform in various l

13 nuclear power plant applications, including those 14 subject to much more severe thermal environments than 15 that of the spent fuel pool.

Stainless steel maintains 16 its integrity and long-term stability at temperatures i

17 0

in excess of 1,000 F, which is far above the 18 temperature expected in the spent fuel pool.

19 Reductions in strength occur with increased steel 20 temperature; however, for the temperature under l

21 0

consideration (212 F and less), no appreciable 22 reduction occurs, as reflected in the ASME Boiler and 23 Pressure Vessel Code,Section III, Nuclear Power Plant 24 Components, Division I, Appendix I.

25 Oll:

Please describe the effect of temperature on the l

26 concrete and reinforcing steel of the spent fuel pool.

27 28 I

m l*,

'l' 1

2-

'All:

The concrete and. reinforcing steel:of the spent fuel' 3

. pool'are also' capable.of maintaining their integrity, S

4

durability and long-term stability under the thermal

.i i

5 environment imposed by the increased pool capacity.

6 Concrete exposed to elevated temperatures will exhibit w

7 some. changes.in its characteristics.

Such changes are 8

dependent'on the type and ' nature.'of the concrete 9

~ constituents and on the proportions in which these 10

' constituents are combined..For concrete. materials, 11' such as those in the Turkey Point spent fuel _ pool.

12

. structure, which have met.the minimum requirements of 13 the controlling ASTM standards and!are combined in

'14 accordance with appropriate'ACI' guidelines, 15 temperatures below approximately 300 F have an

,16 insignificant effect on their properties.

A limestone 17 type aggregate and portland cement, both of which meet 18 appropriate ASTM standards, were used in the Turkey 19 Point spent _ fuel pool.

ACI guidelines as previously 20 identified were employed for proportioning and mixing 21 processes.

]

J 22 Free water, which is the result of excess water

.j 1

'23 available in the wet concrete mix not utilized in the

{

24 hydration process, can be a concern for some structures j

25 with temperatures above approximately 200 F.

However, 26 in the esse of the Turkey Point spent fuel pool 27 concrete structure, more than adequate time (the plant 28

_ lo _

1 2

has been in operation for more than a dozen years) has 3

been available for any free water, which was not 4

utilized in the hydration process, to egress.

5 Therefore, free water does not present a concern with 6

respect to the concrete pool structures at Turkey 7

Point, and these structures will not be adversely 8'

affected by the heat generated in the spent fuel pools.

l 9

Unless the concrete is saturated with moisture (which 10 is not the case at Turkey Point), temperature on the 0

11 order of 300 F will have an insignificant effect on 12 the mechanical properties of the concrete including its 13 strength.

14 Finally, the reinforcing steel in the concrete 15 structure is similar to other steels in that it 16 maintains its integrity and stability at temperatures 17 far above that which will be experienced by the pool 18 structure.

Consequently, any reduction in strength c'.

19 the reinforcing steel as a result of the heat loads 20 experienced Jn the spent fuel pool will be 21 insignificant.

22 Q12:

Does Florida Power & Light Company have a materials 23 surveillance or monitoring program to detect any heat-24 induced degradation of the Turkey Point spent tuel pool 25 liners and concrete pool structures?

26 A12:

No.

Such a program is unnecessary for the following 27 reasons:

28

1;

.]

'2

.. o -

The Turkey Point spent fuel pool. liners and I

L3 concrete structures were designed and licensed,to i

4 store: spent fuel'for the lifetime of the plant.

O

.5 The.-spent fuel. pool expansionIincreases the-amount 6

.of fuel stored but not the duration of use-of the 7'

spent fuel pools.

T

'8 o,

The concrete. pool structure and liner have been 9.

shown to.be' capable of withstanding, without 10L significant-effect upon their, properties, 11 temperatures' exceeding those to which they will be 12 ~

exposed during the lifetime of the plant.

13 Q13:. Would you please summarize your testimony?

14 A13:

The' concrete pool structure and liner were' evaluated to 15 determine whether they could w.',thstand.the thermal 16 '-

stresses and~ heat loads expected as a result of the

.{

1

-17 spent fuel pool expansion.

This evaluation l

.18 demonstrates that the concrete pool structure and liner 19 will maintain their integrity.for the maximum 20 temperature differentials expected for the Turkey Point 21 spent fuel pool.

Furthermore, both the liner and the 1

22 pool structure. consist of materials which are widely 23 used in the nuclear industry and which have a proven

~24 ability to withstand the heat loads expected in the 25 Tur' key Point spent fuel pool.

26 27 J

28 k

• l 1

2 EXHIBIT A 3

STATEMENT OF PROFESSIONAL QUALIFICATIONS OF EUGENE W. THOMAS 5

CURRENT POSITION Assistant Chief Civil Engineer, Bechtel Eastern Power Corporation EDUCATION BSCE, Drexel Institute of Technology, 7

1964 MSME, Drexel Institute of Technology, 8

1969 9

SUMMARY

10 l

1/2 Year Assistant Chief Civil Engineer, Bechtel, 1987-Present 5 Years Civil staff supervisor, Bechtel, 1982-l 12 1987 13 2-1/2 Years Civil group supervisor, nuclear power plant, Bechtel, 1979-1982 3-1/2 Years Deputy civil group supervisor, nuclear i

i 15 power plant, Bechtel, 1976-1979 16 2-1/2 Years Group leader, nuclear power plant, Bechtel, 1973-1976 3-1/2 Years Engineering specialist, nuclear power 18 plants, Bechtel, 1970-1973 19 6 Years Senior dynamics engineer and dynamics

• 9 9'

20 l

EXPERIENCE WITH BECHTEL Mr. Thomas is currently serving as Assistant Chief Civil Engineer in the Civil Engineering Department.

In this l

position, he provides technical assistance to the chief civil engineer, reviews the technical adequacy of engineering design for both fossil and nuclear power plant projects, 26 develops design methods and standards, and acts as a 28

l L

'l 2-consultant to the various projects in resolution of difficult 3

or unusual problems.

Mr. Thomas is also a member of 4

Bechtel's Dynamics Committee, which establishes criteria for 5

seismic analyses and design criteria for vibrating and 6

rotating equipment.

7 Mr. Thomas served as the civil staff supervisor 8

prior 1to this'with duties and responsibilities similar to 9.

those in his current position.

10 Previously, Mr. Thomas was assigned as civil group 11 supervisor for the' multi-unit SNUPPS project, 1150 MW PWR 12 nuclear units, involving several utilities.

He was 13 responsible for design of the powerblock and safety-related 14 site structures, technical resolution of field problems, 15 preparation of specifications and bid packages, technical 16 evaluation of bids, and review of vendor drawings for civil 17 related items.

18 In earlier assignments to SNUPPS, Mr. Thomas was 19 deputy group supervisor and reacter building group leader.

20 As an engineering specialist, Mr. Thomas was 21-involved in piping whip restraint design, miscellaneous 22 concrete and structural steel design, and FSAR preparation 23-for Millstone Nuclear Power Station's 870 MW PWR Unit 2 for 24 Northeast Nuclear Energy Company.

He also worked on pipe 25 whip restraint desigr. for the Davis-Besse Nuclear Power 26 Station 900 MW PWR Unit 2 project for the Toledo Edison 27 Company /The Cleveland Electric Illuminating Company; seismic 28 l,

1 2

analysis for the auxiliary and control buildings, pipe hanger 3

design and miscellaneous concrete and structural steel design l

4 for the 693 MW PWR Turkey Point Plant Units 3 and 4 for 5

Florida Power & Light Company; and seismic analysis of the 6

containment for the Edwin I. Hatch Nuclear Plant, two 800 MW 7

BWR units for Georgia Power Company.

8 EXPERIENCE WITH BOEING 9

l Prior to joining Bechtel, Mr. Thomas was a senior dynamics engineer and dynamics engineer.

Using flight test data, finite element and other analytical methods, he determined dynamic characteristics of air frames.

He also prepared computer programs for predicting rotor dynamic loads on helicopters and for determining structural natural frequencies for large models.

17 PROFESSIONAL MEMBERSHIPS 18 National Society of Professional Engineers, American Concrete Institute i

g REGISTRATION Registered Professional Engineer in Maryland, Missouri, 21 and Kansas 22 23 l

I 24 25 l

26 27 28 o

i