ML17277A406

Forwards Request for Addl Info to Complete Review of Standby Svc Water Multiplexer Sys.Response Requested by 830211.Notification within 7 Days of Receipt of Ltr Requested If Schedule Cannot Be Met

ML17277A406
Person / Time
Site:	Columbia
Issue date:	01/10/1983
From:	Schwencer A Office of Nuclear Reactor Regulation
To:	Ferguson R WASHINGTON PUBLIC POWER SUPPLY SYSTEM
References
NUDOCS 8301130190
Download: ML17277A406 (7)

Text

JAN )0 ]ggy Docket No.:

50-397.'

DISTRIBUTION:

LDocket FileRC PDR Local PDR NSIC PRC Yir.

R.

L. Ferguson Mana'.g.ing Director Washington Public Power Supply P. 0.

Box 968 3000 George Washington Way Richland, Washington

99352,

Subject:

WNP-2 FSAR - Request LB¹2 File RAul uck System EHylton

Paton, OELO Region V

ELJordan, DEQA:IE JMTaylor ORP IIE ERossi JRosenthal for AdditSSI MiormatIoo As a result of our review of your.Standby Service Water ffultiplexer

System, we find that we need additional information.

Our review and the specific information request is described in Enclo;sure 1.

To maintain our licensing review schedule for the HNP-2, we will need responses to the enclosed request by Febr,'uary 11, 1983. If you cannot meet this date, please inform us within sevenddays after receipt of this letter of the date you plan to submit -jour responses m that we may review our schedule for any necessary changes.

Please contact Raj Aulu.'ck, Licensing Project ttanager, if you desire any discussion or clarification of the enclosed r equest.

Sincer ly,

Enclosure:

As stated A. Schwencer, Chief Licensing Branch No.

2 Division of Licensing cc:

See next page 830ii30i90 8301i0 POR AoaCK OS0OOS97 A

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WNP-2 Mr. R. L. Ferguson Managing Director Washington Public Power Supply System P. 0.

Box 968 3000 George Washington Way

Richland, Washington 99352 CC:

Nicholas Reynolds, Esquire Deb evoi se 5 Lib e rman 1200 Seventeenth

Street, N.

W.

Washington, D. C.

20036 Mr. G.E.

Doupe, Esquire Washington Public Power Supply System P.O.

Box 968 3000 George Washington Way

Richland, Washington 99352 Nicholas Lewis, Chairman Energy Facility Site Evaluation Council Mail Stop PY-ll Olympia, Washington 98504 Roger Nelson, Licensing Manager Washington Public Power Supply System P.O.

Box 968

Richland, Washington 99352 Mr. W.G. Conn, Sr.

N/M Group Supervisor Burns and Roe, Incorporated 601 Williams Boulevard

Richland, Washington 99352 Mr. Richard Feil U.S.

NRC Resident Inspector WPPSS-2 NPS P.O.

Box 69

Richland, Washington 99352 Dr. G.D.

Bouchey Deputy Director, Safety 5 Security Washington Public Power Supply System P.O.

Box 968, MD 650

Richland, Washington 99352

ENCLOSURE l.

WNP-2 STANDBY SERVICE WATER MULTIPLEXER SYSTEM The control of the WNP-2 standby service water system is provided using a

multiplexer system.

Staff concerns related-to the multiplexer are enumerated in the WNP-2 SER, where it is identified as ap open item.

A meeting was held on May 19, 1982, to discuss these concerns.

The meeting followed the agenda provided by R. Auluck in the meeting notice of May.6, 1982.

WPPSS supplied a summary of the meeting and response to additional questions by letter from G.D.

Bouchey, WPPSS, to A. Schwencer,

NRC, GO 2-82-634, August 2, 1 982.

The purpose of the meeting, and response to additional questions, was to provide the staff with sufficient information concerning the operation and potential failure modes of the multiplexer system to enable the staff to judge conformance to the applicable General Design Criteria and Reg-ulatory Guides.

Based on the information provided to the staff, two substantive concerns remain:

(1) qualification of the multiplexers for electromagnetic inter-

ference, and (2) the fault tolerance of the plant design should the multiplexers exhibit non-mechanistic common mode failure.

WPPSS has addressed these issues in their August 2, 1982 letter.

Response

f031.139 (7) clearly states "no specific EMI tests have been performed on the multiplexing system."

The response'includes t'echnical'rguments that the multiplexer equipment is not susceptible to EMI.

However, similar equipment, i.e.,

equipment employing 'l,ike components, has been routinely teste'd for EMI susceptibility.

The susceptibility of the equipment to EMI is a function of the specific component physical and electrical configuration and of the card/module packaging.

The susceptibility to EMI is not readily ascertained, short of testing.

Hence specific EMI testing should be performed.

The testing may be performed in a laboratory or in the field.

The Supply System should demonstrate that the multiplexer equipment'is not susceptible to the EMI environment of the plant.

Radiative and conductive coupling should be considered.

Electrical noise sources to be considered should i'nclude:

radiation from portable cormunication equipment, large electric motors and breakers, arc welders, and lightning.

A test plan should be prepared and submitted to the staff prior to testing'.

Test results should be submitted subsequent to testing.

The test results should qualitatively and quantitatively demonstrate that the goals of the test plan have been met, show deficiencies, and remedial action.

Response

9031.139(2) discusses manua'nitiation of the standby service water system independent of the remote multiplexer operation.

The standby service water pump could be operated at the switchgear and valves may be hand operated from the service vater pumphouse.

The applicant has estimated that upon reaching a service water pumphouse it would require about 20 minutes each to open 3 valves.and an additional 2 minutes each to open 2 additional valves, in order to place one division of standby service water in operation.

Clearly these times are too long to protect the plant by manual operation should the multiplexers fail.

For example, a diesel, upon starting in response to a loss of offsite power, will fail if cooling water from the standby service water system is not provided to, the diesel within about a minute if diesel protection is bypassed or fails.

The staff will require that the applicant modify the plant design such that the standby service water system may be manually initiated and/or aligned independent of the multiplexers in. a timely manner.

The applicant should determine the time duration following plant trip that decay heat may be transferred from the core to contain-ment (suppression pool) prior to exceeding containment design limits without operation of the standby service water system.

The applicant should modify the plant such that the standby service water system may be placed into service within the time duration determined above assuming common mode failure of the standby service water multiplexers.

Equipment which is required for long term heat removal should be suitably protected following plant trip and subsequent equipment demand and prior to postulated delayed operation of the standby service water system.

The ACRS letter to Chairman Palladino, "ACRS Report on ',washington Public Pow e Supply System Nuclear Project No. 2", October 13, 1982 discusses this matter and states:

"Because of 'the importance of this system to

safety, we recommend that the NRC Staff confirm that service water needed for shutdown decay heat removal can be made available even if the multi-plexing system'alfunctions.

The Committee wishes to be kept informed regarding this matter."

031.140 Demonstrate that the multipl"x"r quips>ent used in the 'standby service water system"is not susceptible to the EMI environment. of the plant.

Radiative and conductive coupling should be considered.

Electrical noise sources to be considered should include:

radiation from portable comm-unication -equipment, large electric motors and breakers, arc welders, and lightning.

A test plan should be prepared and submitted to the NRC staff prior to testing.

Test results should be submitted subsequent to testing.

The test results should qualitatively and quantitatively demonstrate that the goals of the test plan have been met, show defi-

ciencies, and remedial action.

~

's V

I II 031.141 Hodify the plant design such that the standby service water system. may be manually initiated and/or aligned independent of the multiplexers in a timely manner.

Determine the",time duration following plant trip that decay heat may be transferred from the core to containment (suppression pool) prior to exceeding containment design limits without operation of the standby service water system.

The design should be modified such that the standby. service water system may be placed into service within the time duration determined above assuming common mode failure of hhe standby service water multiplexers.

Equipment which is required for long term heat removal should be suitably protected following plant trip and subsequent equipment demand and prior to postulated delayed operation of the standby service water system.