ML20217H358
| ML20217H358 | |
| Person / Time | |
|---|---|
| Site: | Duane Arnold  |
| Issue date: | 03/31/1998 |
| From: | Richard Laufer NRC (Affiliation Not Assigned) |
| To: | Leslie Liu IES UTILITIES INC., (FORMERLY IOWA ELECTRIC LIGHT |
| References | |
| GL-96-06, GL-96-6, TAC-M96808, NUDOCS 9804030282 | |
| Download: ML20217H358 (6) | |
Text
'
- 3 Mr. Lee Liu Ch:irmin of the BS:rd
- and Chief Executive Officer IES Utilities Inc.
200 First Street, SE.
P.O. Box 351 Cedar Rapids, IA 52406-0351
SUBJECT:
REQUEST FOR ADDITIONAL INFORMATION RELATED TO THE GL 96-06 RESPONSE FOR THE DUANE ARNOLD ENERGY CENTER (TAC NO. M96808).
Dear Mr,
Liu:
Generic Letter (GL) 96-06, " Assurance of Equipment Operability and Containment Integrity During Design-Basis Accident Conditions," dated September 30,1996, included a request for licensees to evaluate cooling water systems that serve containment air coolers to assure that they are not vulnerab!e to waterhammer and two-phase flow conditions. By letter dated January 28,1997, you provided the assessment for the Duane Arnold Energy Center. Based on its review of your response, the staff has determined that additional information is required to complete its review. Please provide written responses to the enclosed request for additional Information by June 30,1998.
Sincerely, Original signed by:
Richard J. Laufer, Project Manager Project Directorate ill-3 Division of Reactor Projects ill/IV Office of Nuclear Reactor Regulation Docket No. 50-331
Enclosure:
As stated cc w/o enc!: See next page Distribution w/ encl:
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M rch 31, 1998 Mt W W Ch:irm:n of the Borrd cnd Chtf Executiva Officer IES Utilities Inc.
200 First Street, SE.
P.O. Box 351 4
Cedar Rapids, IA 52406-0351
SUBJECT:
REQUEST FOR ADDITIONAL INFORMATION RELATED TO THE GL 96-06 RESPONSE FOR THE DUANE ARNOLD ENERGY CENTER (TAC NO. M96808)
Dear Mr. Liu:
Generic Letter (GL) 96-06, " Assurance of Equipment Operability and Containment integrity During Design-Basis Accident Conditions," dated September 30,1996, included a request for licensees to evaluate cooling water systems that serve containment air coolers to assure that they are not vulnerable to waterhammer and two-phase flow conditions. By letter dated January 28,1997, you provided the assessment for the Duane Arnold Energy Center. Based on its review of your response, the staff has determined that additional information is required to complete its review. Please provide written responses to the enclosed request for additional information by June 30,1998.
Sincerely, Original signed by:
Richard J. Laufer, Project Manager Project Directorate lil-3 Division of Reactor Projects lil/IV Office of Nuclear Reactor Regulation Docket No. 50-331
Enclosure:
As stated cc w/o encl: See next page Qistribution w/ encl:
Docket File PUBLIC PDill-3 R/F w/o encl:
EAdensam (EGA1)
GGrant, Rill ACRS OGC,015B18 RSavio G:\\DUANEARN\\DUA96808.RAI OFFICE PM:PDill-3 E LA:PDill-3 lE J
NAME RLaufer 0.V EBamhill &
DATE 4/W98 b6l/98 OFFICIAL RECORD GOPY 1
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NUCLEAR REGULATORY COMMISSION 2
WASHINGTON, D.C. 20066-0001
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,d March 31, 1998 Mr. Lee Liu Chairman of the Board and Chief Executive Officer IES Utilities Inc.
200 First Street, SE.
P.O. Box 351 Cedar Rapids, lA 52406-0351
SUBJECT:
REQUEST FOR ADDITIONAL INFORMATION RELATED TO THE GL 96-06 RESPONSE FOR THE DUANE ARNOLD ENERGY CENTER (TAC NO. M96808)
Dear Mr. Liu:
Generic Letter (GL) 96-06, " Assurance of Equipment Operability and Containment Integrity During Design-Basis Accident Conditions," dated September 30,1996, included a request for licensees to evaluate cooling water systems that serve containment air coolers to assure that they are not vulnerable to waterhammer and two-phase flow conditions. By letter dated January 28,1997, you provided the assessment for the Duane Arnold Energy Center. Based on its review of your response, the staff has determined that additionalinformation is required to complete its review. Please provide written responses to the enclosed sequest for additional information by June 30,1998.
Sincerely, AJJ/-
u Richard J. Laufer, Project Manager Project Directorate ill-3 Division of Reactor Projects lil/IV Office of Nuclear Reactor Regulation Docket No. 50-331
Enclosure:
As stated cc w/o encl: See next page
Lee Liu Duane Arnold Energy Center IES. Utilities Inc.
' CC.*
Jack Newman, Esquire Kathleen H. Shea, Esquire Morgan, Lewis, & Bockius 1800 M Street, NW.
Washington, DC 20036-5869 Chairman, Linn County Board of Supervisors Cedar Rapids, IA 52406 IES Utilities Inc.
ATTN: Gary Van Middlesworth Plant Superintendent, Nuclear 3277 DAEC Road Palo,lA 52324 John F. Franz, Jr.
Vice President, Nuclear Duane Arnold Energy Center 3277 DAEC Road Palo,IA 52324 Ken Peveler Manager of Regulatory Performance Duane Arnold Energy Center 3277 DAEC Road Palo, IA 52324 U.S. Nuclear Regulatory Commission Resident inspector's Office Rural Route #1 Palo,IA 52324 Regional Administrator, Rlll U.S. Nuclear Regulatory Commission 801 Warrenville Road Lisle, IL 60532-4531 Parween Baig.
Utilities Division j
lowa Department of Commerce Lucas Office Building,5th floor Des Moines, IA 50319
4-
- 1 REQUEST FOR ADDITIONAL INFORMATION FOR RESOLUTION OF GL 96-06 ISSUES AT THE DUANE ARNOLD ENERGY CENTER (TAC NO. M96808).
Generic Letter'(GL) 96-06, " Assurance of Equipment Operability and Containment Integrity During Design-Basis Accident Conditions," dated September 30,1996, included a request for licensees to evaluate cooling water systems that serve containment air coolers to assure that they are not vulnerable to waterhammer and two-phase flow conditions. IES Utilities Inc. (the licensee) provided its assessment for the Duane Amold Energy Center in a letter dated January 28,1997. The licensee's response indicated that the drywell air cooling system is non-safety related and that the cooling water system is isolated on a Group 7 (Reactor Building Closed Cooling Water and Well Water Containment Cooling) isolation. The licensee indicated '
that the drywell temperature could reach 340* F during a small break loss-of-coolant accident (LOCA) and, since system pressure relief valves are set for 220 psig (saturation temperature of 396* F), boiling will not occur in the isolated cooling water system during accident conditions.
1 On this basis, the licensee concluded that the cooling water system serving the drywell air i
coolers is not subject to waterhammer or two-phase flow. The licensee's response summarizes j
one possible scenario, but this may not be representative of the worst-case scenario.
l Therefore, in order to assess the licensee's resolution of the waterhammer and two-phase flow issues, the following additional information is requested:
1.
Confirm that all possible event scenarios have been consideree in 6 rriving at the worst case situation for both waterhammer and two-phase flow condit.~ons. Provide a detailed description of the " worst case" scenarios for waterhammer and two-phase flow, taking into consideration the complete range of event possibilities, system configurations, and parameters. For example, loss of power with full and partial system drain-down should be considered, all waterhammer types and water slug scenarios should be considered, as well as temperatures, pressures, flow rates, load combinations, and potential component failures. Additional examples include:
the consequences of steam formation, transport, and accumulation;
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cavitation, resonance, and fatigue effects; and
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erosion considurations.
=
Licensees may find NUREG/CR-6031, " Cavitation Guide for Control Valves," helpful in addressing some aspects of the two-phase flow analyses.'
2.
In determining the worst-case scenarios for waterhammer and two-phase flow, confirm that a complete failure modes and effects analysis (FMEA) for all components (including electrical and pneumatic failures) that could impact performance of the cooling water '
system was performed and confirm that the FMEA is documented and available for review, or explain why a complete and fully documented FMEA was not performed.
Enclosure 1
,o w
2 9
~ f a methodology other than that discussed in NUREG/CR-5220, " Diagnosis of 3.
I Condensation-Induced Waterhammer," was used in evaluating the effects of waterhammer, describe this alternate methodology in detail. Also, explain why this methodology is applicable and gives conservative results for the Duane Arnold Energy Center (typically accomplished through rigorous plant-specific modeling, testing, and analysis).
4.
Identify any computer codes that were used in the waterhammer and two-phase flow analyses and describe the methods used to bench mark the codes for the specific loading conditions involved (see Standard Review Plan Section 3.9.1).
5.
Describe and justify all assumptions and input parameters (including those used in any computer codes) such as amplifications due to fluid structure interaction, cushioning, speed of sound, force reductions, and mesh sizes, and explain why the values selected give conservative results. Also, provide justification for omitting any effects that may be relevant to the analysis (e.g., fluid structure interaction, flow induced vibration, erosion).
6.
Explain and justify all uses of " engineering judgement" in your analyses of waterhammer and two-phase flow conditions.
7.
Determine the uncertainty in the waterhammer and two-phase flow analyses, explain how the uncertainty was determined, and how it was accounted for in the analyses to assure conservative results for the Duane Amold Energy Center.
8.
Confirm that the waterhammer and two-phase flow loading conditions do not exceed any design specifications or recommended service conditions for the piping system and components, including those stated by equipment vendors; and confirm that the system will continue to perform its design-basis functions as assumed in the safety analysis report for the facility.
9.
Provide a simplified diagram of the system, showing major components, active components, relative elevations, lengths of piping runs, and the location of any orifices and flow restrictions.
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