ML20155F271

Requests NEI Assistance in Obtaining Info Re PWR Sump Performance as Related to GSI 191, Assessment of Debris Accumulation on PWR Sump Performance

ML20155F271
Person / Time
Issue date:	11/02/1998
From:	Berlinger C NRC (Affiliation Not Assigned)
To:	Modeen D NUCLEAR ENERGY INSTITUTE (FORMERLY NUCLEAR MGMT &
References
PROJECT-689, REF-GTECI-*****, REF-GTECI-A-43, REF-GTECI-ES, REF-GTECI-NI, RTR-REGGD-01.082, RTR-REGGD-1.082, TASK-***, TASK-A-43, TASK-OR NUDOCS 9811050374
Download: ML20155F271 (7)

Text

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! Mr. D vid Mod 2cn, Director' ~ November 2, 1998 ,

, Engineering Nuclear Energy institute Suite 400 1776 i Street, NW Washington, DC 20006-3708.

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SUBJECT:

PRESSURIZED WATER REACTOR SUMP PERFORMANCE

Dear Mr. Modeen:

The NRC staff is beginning work on Generic Safety Issue 191, " Assessment of Debris )

Accumulation on Pressurized Water Reactor Sump Performance." As part of this work, the '

i staff intends to study the entire spectrum of operating pressurized water reactor (PWR) sump l designs. The purpose of this study is to determine whether current NRC guidance in this area, particularly NRC Regulatory Guide 1.82, " Water Sources for Long-Term Recirculation Cooling l Following a Loss-of-Coolant Accident " should be revised based on information that the staff l has obtained since the resolution of Unresolved Safety Issue A-43, " Containment Emergency Sump Performance." i l The staff has surveyed the information available in the Updated Final Safety Analysis Reports i for these plants and has not been able to obtain all the required information. Therefore, we are requesting the assistance of the Nuclear Energy Institute (NEI) in obtaining this information. I have discussed this matter with Mr. John Butler of your staff. He has indicated NEl's I willingness to consider working with the industry to obtain this information. ,

l The specific information we are requesting is enclosed. In order to be useful to us, the information must be available to the public and should be in a detailed form useful for calculations and other studies. Plant identification would be useful but is not necessary. If plant identification is not provided, then additional information would be necessary. This information includes the type of containment (large dry, subatmospheric, ice condense ), power level and ECCS configuration. Thank you for your help on this issue.

Sincerely, Original Signed By:

Carl H. Berlinger, Chief Containment Systems 9811050374 981102 and Severe Accident Branch PDR REVGP ER C Division of Systems Safety and Analysis Office of Nuclear Reactor Regulation Project No. 689

Enclosure:

As stated

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. . . . . ,o November 2, 1998 Mr. David Modeen, Director Engineering Nuclear Energy Institute Suite 400 1776 l Street, NW Washington, DC 20006-3708

SUBJECT:

PRESSURlZED WATER REACTOR SUMP PERFORMANCE

Dear Mr. Modeen:

The NRC staff is beginning work on Generic Safety issue 191, " Assessment of Debris Accumulation on Pressurized Water Reactor Sump Performance." As part of this work, the staff intends to study the entire spectrum of operating pressurized water reactor (PWR) sump l designs. The purpose of this study is to determine whether current NRC guidance in this area, i particularly NRC Regulatory Guide 1.82, " Water Sources for Long-Term Recirculation Cooling Following a Loss-of-Coolant Accident," should be revised based on information that the staff has obtained since the resolution of Unresolved Safety Issue A-43," Containment Emergency Sump Performance."

l The staff has surveyed the information available in the Updated Final Safety Analysis Reports for these plants and has not been able to obtain all the required information. Therefore, we are I requesting the assistance of the Nuclear Energy institute (NEl)in obtaining this information. I have discussed this matter with Mr. John Butler of your staff. He has indicated NEl's willingness to consider working with the industry to obtain this information.

The specific information we are requesting is enclosed. In order to be useful to us, the ,

information must be available to the public and should be in a detailed form useful for calculations and other studies. Plant identification would be useful but is not necessary. If plant identification is not provided, then additional information would be necessary. This information includes the type of containment (large dry, subatmospheric, ice condenser), power level and ECCS configuration. Thank you for your help on this issue.

Sincerely F -- --

Carl H. Berlinger, ChiefU Containment Systems and Severe Accident Branch Division of Systems Safety and Analysis Office of Nuclear Reactor Regulation Project No. 689

Enclosure:

As stated

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o NOTE: The requested information includes information on ECCS and containment spray (CS)

NPSH. If this information has already been provided to the NRC in response to GL 97-04, 1

" Assurance of Net Positive Suction Head for Emergency Core Cooling and Containment Heat j l Removal Pumps", it is sufficient to indicate this. -

Requested Information Unit 1

1. What is the limiting break,if any, used to assess impact of debris n/a generation on ECCS design / performance?

2. - What is the basis for size of the sump screen (e.g.,50% blockage)? n/a l a. If the basis for the sump screen size is 50% blockage, what n/a measure have been taken to ensure that no more 50% of the sump screen is blocked, thus ensuring proper operation of the ECCS?

3. What is the basis for the hole size in the sump screen (e.g., spray n/a l nozzle, throttle valve clearances)?

4. What procedures,if any, are available to switch to an alternate n/a l water source if the sump is unavailable?

a. What are the alternate water sources? n/a

b. How long will it take to align and switch to alternate water min sources?

5. Following a Large Break LOCA (LBLOCA), what is the containment ft flood level (depth of water on floor) at time switch over from refueling water storage tank (borated water storage tank)?

a. Following a LBLOCA, when does the low pressure safety sec injection (LPSI), residual heat removal (RHR), or recircuating pumps start to draw suction from the sump?

b. What is the boron concentration in water on the ppm containment floor?

6. Following a LBLOCA, what is the maximum containment flood ft level?

a. Following a LBLOCA, when is the rnaximum containment sec flood level reached?

b. What is the boron concentration in water on containment ppm floor?

I l Enclosure

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Requested information Unit

c. Which water sources are used to determine flood level (e.g., n/a 1

RCS spillage, RWST inventory, containment spray, ice melt, etc.)?

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7. Following a LBLOCA, what is the maximum containment sump F l temperature?

8. How many LPSI/RHR pumps? n/a

9. What is the required NPSH for LPSI/RHR pumps? ft of H O

_ _ _ _ . _ _ _ _ . _ . - . _ _ _ _ . . . _ _ _ _ . _ _ _ . _ _ _ _ __.._2_

10. Following a LBLOCA, what is the available NPSH for LPSI/RHR ft of H2O ,

pumps? I

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a. At what temperature was this NPSH calculated? F l

b. At what flowrate was this NPSH calculated? gpm

11. What is the maximum flowrate for LPSI/RHR pumps? gpm

_.12. _ ..__._ _What is the rated flowrate for LPSI/RHR pumps?

gpm

13. How many CS pumps? n/a

14. What is the required net positive suction head (NPSH) for ft of H2O containment spray (CS) pumps?

_ 15. . - - Following a LBLOCA, what is the available NPSH for CS pumps?

ft of H2 O

a. At what temperature was this NPSH calculated? F

b. At what flowrate was this NPSH calculated? gpm

16. What is the maximum flowrate for CS pumps? gpm

17. What is the rated flowrate for CS pumps? gpm

18. Provide a sketch of the containment sump (s). n/a

a. How many containment (recirculating) sumps? n/a

b. What is the depth below containment floor of containment ft (recirculating) sump (s)?

c. What is the height above the containment floor of the ft containment (recirculating) sump screen (s)?

d. Does the sump have a screen? n/a 2

i e. How much screen area is available for debris ft accumulation?

Enclosure l

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Requested Information Unit

! f. What is the hole size in the sump screen? inch

g. Does the sump have a trash rack? n/a

h. What is the distance between the sump screen and the inch trash rack?

1. How much trash rack is available for debris accumulation? ft2

j. What is the hole size in the trash rack? inch

_ _ . _ . . .k._ . _ _ _ _ . .Does the sump have a solid or screen cover plate? .

n/a

l. Inside the sump does the ECCS pumps draw suction n/a through a vortex suppressor or strainer, if so provide a sketch?

m. Does the sump have a debris curb? n/a l n. What is the height of the debris curb? ft

o. What is the distance between the debris curb and sump ft screen?

19. Provide a plan view sketch of the containment elevation that the n/a

sumps are located.

_ _ _ _ _ _a._...._. _ ._ __ _What is the containment floor area (open area only)? .._ _ . , _ . _ _ - _ _ _ . . _ _ _ _ _ _ ._. _

ft2

b. Where are the sumps located? n/a

c. How many compartments in containment? n/a

d. What are the size of openings between compartments? ft

e. How many openings between compartment? n/a I f. What are the locations of openings between compartments? n/a

20. List the types of qualified coatings in containment. n/a

21. List the types of unqualified coatings in containment. n/a

22. List the types of thermal insulations in containment. n/a

23. List the types of fire barrier materials in containment. n/a

24. List the types of filter materials in containment. n/a Enclosure L

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O Nuclear Energy Institute Project No. 689 i

cc: Mr. Ralph Beedle Ms. Lynnette Hendricks, Director l Senior Vice President Plant Support i and Chief Nuclear Officer Nuclear Energy Institute l Nuclear Energy Institute Suite 400 l

Suite 400 1776 i Street, NW l 1776 l Street, NW Washington, DC 20006-3708 Washington, DC 20006-3708 l

l Mr. Alex Marion, Director Mr. Chsries B. Brinkman, Director L Programs Washington Operations l Nuclear Energy Institute ABB-Combustion Engineering, Inc.

Suite 400 12300 Twinbrook Parkway, Suite 330 1776 i Street, NW Rockville, Maryland 20852 Washington, DC 20006-3708 Mr. David Modeen, Director

, Engineering Nuclear Energy Institute Suite 400 1776 l Street, NW Washington, DC 20006-3708 i Mr. Anthony Pietrangelo, Director Licensing Nuclear Energy Institute Suite 400 1776 l Street, NW Washington, DC 20006-3708 Mr. Nicholas J. Liparuto, Manager Nuclear Safety and Regulatory Actaities Nuclear and Advanced Technology Division Westinghouse Electric Corporation l

P.O. Box 355 Pittsburgh, Pennsylvania 15230 Mr. Jim Davis, Director l Operations Nuclear Energy Institute Suite 400 1776 i Street, NW Washington, DC 20006-3708 l

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