Information Notice 2009-06, Construction-Related Experience with Flood Protection Features

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Construction-Related Experience with Flood Protection Features
ML090300546
Person / Time
Issue date: 07/21/2009
From: Edmund Kleeh
NRC/NRO/DCIP/CCIB
To:
Kleeh E, NRO/DCIP/CCIB, 415-2964
References
IN-09-006
Download: ML090300546 (4)


UNITED STATES

NUCLEAR REGULATORY COMMISSION

OFFICE OF NUCLEAR REACTOR REGULATION

OFFICE OF NEW REACTORS

WASHINGTON, DC 20555-0001 July 21, 2009 NRC INFORMATION NOTICE 2009-06: CONSTRUCTION-RELATED EXPERIENCE WITH

FLOOD PROTECTION FEATURES

ADDRESSEES

All holders of operating licenses for nuclear power reactors and fuel cycle facilities, except those

who have permanently ceased operations and have certified that fuel has been permanently

removed from the reactor vessel; all current and potential applicants for an early site permit, combined license, or standard design certification for a nuclear power plant under the provisions

of Title 10 of the Code of Federal Regulations (10 CFR) Part 52, Licenses, Certifications, and

Approvals for Nuclear Power Plants; all current holders of and potential applicants for

construction permits under 10 CFR Part 50, Domestic Licensing of Production and Utilization

Facilities.

PURPOSE

The U.S. Nuclear Regulatory Commission (NRC) is issuing this information notice (IN) to alert

addressees of construction-related operating experience involving inadequate flood protection

features. The NRC expects recipients to review the information for applicability to their facilities

and to consider actions, as appropriate, to avoid similar problems. However, suggestions

contained in this IN are not NRC requirements; therefore, no specific action or written response

is required.

DESCRIPTION OF CIRCUMSTANCES

Catawba Nuclear Station, Units 1 and 2 - Auxiliary Feedwater Pump Room Floor Drains

On January 30, 2008, at the Catawba Nuclear Station, the licensee declared the Unit 1 and

Unit 2 auxiliary feedwater (AFW) pumps inoperable. The reason for this declaration was that a

licensee engineer discovered, contrary to plant drawings, that a total of nine flow restrictor

plates (three for Unit 1 and six for Unit 2) were missing in the drains, of the interior steamline

and feedline penetration rooms, that route water to the floor drain sumps located in the AFW

pump room of each unit. It appeared that this deficiency of the missing flow restrictor plates

dated back to initial construction of the plant. The drawings called for each floor drain to have a

flow restrictor plate with a 1.588 centimeters (5/8-inch) orifice. Calculations indicated that, with

all the flow restrictor plates installed, the flow would be limited so as not to exceed the capacity

of the AFW sump pumps following a postulated main feedwater line break in one of two

steamline and feedline penetration rooms per unit. This problem of the missing flow restrictor

plates was only with the interior steamline and feedline penetration room per unit, not the

exterior one.

The licensee also found that a historical calculation inappropriately assumed the following: (1) a

non-conservative flood level and only two drains for each interior steamline and feedline

penetration room, and (2) the availability of the floor drain sump pumps in each AFW pump

room (which do not receive emergency power) to mitigate an event. Additional information is

available in Catawba Licensee Event Report 50-413/2008-001, dated March 31, 2008, which

can be found on the NRCs public Web site in the Agencywide Documents Access and

Management System (ADAMS), under Accession No. ML080940127.

Nogent, Units 1 and 2, in France - Flooding Caused by a Large Leak in a Condenser

Circulating Water Pipe

On February 18, 2006, at the Nogent nuclear plant in France, a significant water leak in a

pumps discharge piping occurred in the Unit 2 condenser circulating water system (CWS), train

1. The leak caused a pressure increase at the interface between the concrete foundation raft

and the concrete floor in the Unit 2 turbine hall, and the turbine hall floor partly lifted about 10 to

12 centimeters (3.9 to 4.7 inches) higher than the foundation raft. The lifting of the turbine floor

caused a misalignment of the manhole inlet and rupture of nearly all the 1.6 centimeters (0.63 inches) diameter floor-to-raft anchor rods distributed around the manhole inlet. Water flooded

the Unit 2 turbine hall through the failed manhole, then flowed through a tunnel connecting the

two units, and flooded the Unit 1 turbine hall. Both turbine halls were filled with water to a height

of about 1 meter (3.28 feet). The water then spread from the tunnel between the units to the

essential service water (ESW) system gallery through penetration sleeves. From the ESW

gallery, the water entered the train A component cooling water pump room via a drain. The

cause of the CWS manhole failure in Unit 2, train 1, was attributed to the specific construction of

the manhole. In train 1, the manhole inlet and cover are bolted to the manholes steel shell

which is anchored to the turbine hall floor rather than concrete foundation raft. Therefore, the

water was able to penetrate the interface between the floor and the foundation raft.

BACKGROUND

Applicable Regulatory Documents:

1. Regulatory Guide 1.59, Revision 2, Design Basis Floods for Nuclear Power Plants

(ADAMS Accession No. ML003740388), dated August 1977, describes how nuclear power

plants should be designed to prevent the loss of capability for cold shutdown and

maintenance thereof resulting from the most severe flood conditions that can be reasonably

predicted to occur at a site as a result of severe hydro-meteorological conditions, seismic

activity, or both.

2. NUREG-1174, Evaluation of Systems Interactions in Nuclear Power Plants," dated May

1989, describes technical findings related to unresolved safety issue A-17. Generic Issue

77, which was incorporated into the resolution of safety issue A-17, involved internal

flooding in nuclear power plants. 3. NUREG-1055, Improving Quality and the Assurance of Quality in the Design and

Construction of Nuclear Power Plants (ADAMS Accession No. ML063000293), dated May

1984, alerts addresses to the lessons learned during the construction of nuclear plants in the

United States.

DISCUSSION

The operating experience discussed in this IN involves deficiencies in flood protection features

that originated during construction. Such problems often stem from the failure to adequately

translate the plant design basis requirements into the initial design. General Design Criterion 2, Design Bases for Protection Against Natural Phenomena, of Appendix A to 10 CFR 50,

provides plant design requirements regarding the ability to withstand the effects of natural

phenomena such as floods. In addition, the above Catawba example illustrates the importance

of developing and implementing an effective change process as required by 10 CFR 50,

Appendix B, Criterion III, Design Control, during initial plant design and construction.

CONTACT

This information notice requires no specific action or written response. Please direct any

questions about this matter to the technical contacts listed below.

/RA/ /RA/

Timothy J. McGinty, Director Glenn Tracy, Director

Division of Policy and Rulemaking Division of Construction Inspection and

Office of Nuclear Reactor Regulation Operational Programs

Office of New Reactors

Technical Contacts: Omid Tabatabai, NRO/DCIP Edmund Kleeh, NRO/DCIP

(301) 415-6616 (301) 415-2964 omid.tabatabai@nrc.gov edmund.kleeh@nrc.gov

Note: NRC generic communications may be found on the NRC public Web site, http://www.nrc.gov, under Electronic Reading Room/Document Collections

ML063000293), dated May

1984, alerts addresses to the lessons learned during the construction of nuclear plants in

the United States.

DISCUSSION

The operating experience discussed in this IN involves deficiencies in flood protection features

that originated during construction. Such problems often stem from the failure to adequately

translate the plant design basis requirements into the initial design. General Design Criterion 2, Design Bases for Protection Against Natural Phenomena, of Appendix A to 10 CFR 50,

provides plant design requirements regarding the ability to withstand the effects of natural

phenomena such as floods. In addition, the above Catawba example illustrates the importance

of developing and implementing an effective change process as required by 10 CFR 50,

Appendix B, Criterion III, Design Control, during initial plant design and construction.

CONTACT

This information notice requires no specific action or written response. Please direct any

questions about this matter to the technical contacts listed below.

/RA/ /RA/

Timothy J. McGinty, Director Glenn Tracy, Director

Division of Policy and Rulemaking Division of Construction Inspection and

Office of Nuclear Reactor Regulation Operational Programs

Office of New Reactors

Technical Contacts: Omid Tabatabai, NRO/DCIP Edmund Kleeh, NRO/DCIP

(301) 415-6616 (301) 415-2964 omid.tabatabai@nrc.gov edmund.kleeh@nrc.gov

Note: NRC generic communications may be found on the NRC public Web site, http://www.nrc.gov, under Electronic Reading Room/Document Collections

ADAMS Accession Number: ML090300546 TAC No. ME0470

OFFICE CCIB:NRO TECH EDITOR TL:CCIB:NRO BC:CCIB:NRO BC:SBPB:NRR BC:OIP

NAME EKleeh KAzariah-Kribbs OTabatabai JStarefos DHarrison CAbrams

DATE 02/04/09 03/03/09 02/04/09 02/06/09 02/20/09 03/12/09 OFFICE PGCB:DPR PGCB:DPR BC:PGCB:DP D:DPR D:DCIP:NRO

NAME DBeaulieu CHawes MMurphy TMcGinty GTracy

DATE 03/24/09 03/25/09 07/15/2009 07/17/2009 07/21/2009