Information Notice 1987-02, Inadequate Seismic Qualification of Diaphragm Valves by Mathematical Modeling and Analysis

Inadequate Seismic Qualification of Diaphragm Valves by Mathematical Modeling and Analysis

ML031130652
Person / Time
Site:	Beaver Valley, Millstone, Hatch, Monticello, Calvert Cliffs, Dresden, Davis Besse, Peach Bottom, Browns Ferry, Salem, Oconee, Mcguire, Nine Mile Point, Palisades, Palo Verde, Perry, Indian Point, Fermi, Kewaunee, Catawba, Harris, Wolf Creek, Saint Lucie, Point Beach, Oyster Creek, Watts Bar, Hope Creek, Grand Gulf, Cooper, Sequoyah, Byron, Pilgrim, Arkansas Nuclear, Braidwood, Susquehanna, Summer, Prairie Island, Columbia, Seabrook, Brunswick, Surry, Limerick, North Anna, Turkey Point, River Bend, Vermont Yankee, Crystal River, Haddam Neck, Ginna, Diablo Canyon, Callaway, Vogtle, Waterford, Duane Arnold, Farley, Robinson, Clinton, South Texas, San Onofre, Cook, Comanche Peak, Yankee Rowe, Maine Yankee, Quad Cities, Humboldt Bay, La Crosse, Big Rock Point, Rancho Seco, Zion, Midland, Bellefonte, Fort Calhoun, FitzPatrick, McGuire, LaSalle, 05000000, Zimmer, Fort Saint Vrain, Shoreham, Satsop, Trojan, Atlantic Nuclear Power Plant, Skagit, Marble Hill, Crane
Issue date:	01/13/1987
From:	Jordan E NRC/IE
To:
References
IN-87-002, NUDOCS 8701120086
Download: ML031130652 (5)

a

SSINS No.: 6835 IN 87-02

UNITED STATES

NUCLEAR REGULATORY COMMISSION

OFFICE OF INSPECTION AND ENFORCEMENT

WASHINGTON, D.C.

20555

Jsuary 13, 1987

IE INFORMATION NOTICE NO. 87-02:

INADEQUATE SEISMIC QUALIFICATION OF DIAPHRAGM

VALVES BY MATHEMATICAL MODELING AND ANALYSIS

Addressees

All nuclear power reactor facilities holding an operating license or a con- struction permit.

Purpose

This notice is provided to alert recipients to a potential problem pertaining

to seismic qualification of safety-related diaphragm valves.

These valves were

furnished as qualified by mathematical analysis based on an inadequate model;

the results of later tests showed that the actual lowest natural frequency of

the valve may be less than that required by the purchase specification.

It is expected that recipients will review this information for applicability

to their facilities and consider actions, if appropriate, to preclude a similar

problem from occurring at their facilities.

However, suggestions contained in

this notice do not constitute NRC requirements; therefore, no specific action

or written response is required.

Description of Circumstances

On December 27, 1984, ITT Engineered Valves (formerly Dia-Flo Division of ITT

Grinnell Valve Co., Inc.) notified purchasers of air-operated valves with

extended operator structures that such valves had been determined by test to

have natural frequencies less than 33 hertz. The notification was directed to

nuclear power plant owners or suppliers who had purchased valves to specifi- cations requiring the valves to have all natural frequencies equal to or

greater than 33 hertz as demonstrated by analysis or test.

The natural frequencies of these valves had been originally determined by

analysis. Subsequent information obtained from testing similar valves dis- closed that the natural frequency of air-operated valves with extended struc- tures is less than 33 Hz.

ITT Grinnell undertook a testing program that

included fragility testing to provide data for evaluating the characteristics

and capabilities of the valves.

On the basis of the fragility testing results, Grinnell drew the generic conclusion that there was not a safety problem

related to valve functionality; this conclusion was presented in the December

27, 1984 notification.

No notification of this problem under 10 CFR Part 21

was made at that time; however, a notification under 10 CFR Part 21 subsequent- ly was received by the NRC from one power plant.

IN 87-02 January 13, 1987 The NRC staff reviewed the test reports obtained from ITT Grinnell and reviewed

the design applications and field installations of such valves to see if they

agreed that there was adequate Justification for a generic conclusion that no

safety problem existed. The NRC staff concluded that generic acceptance of the

valves could not be determined and informed ITT Grinnell that a Part 21 notifi- cation should be issued. As a result, on October 10, 1986 ITT Grinnell issued

two Part 21 notices, one for diaphragm valves with air operators on extended

structures and one for diaphragm valves with Limitorque operators.

The Part 21 notices point out that, in addition to valve considerations, the

piping systems containing these valves and the associated piping supports also

may be affected by the change in frequency and that an evaluation of the

analysis methods used to qualify the valves and of the potential impact on a

system may be required.

Discussion:

The natural frequencies of the diaphragm valves are reflected in the mathemat- ical model and are used for dynamic analyses of those systems requiring dynamic

analysis. Therefore, these results of dynamic analysis using the model affect

predicted accelerations and forces on the valve and its operator, stresses in

the piping, and forces on the pipe supports.

The test results, reported in the Part 21 notices, for valve fragility in terms

of acceleration "g" levels are consistent with those that the NRC obtained from

review of the ITT test report data.

Although the high g levels for fragility

of the valves are impressive, no generic conclusion of valve acceptability can

be made because (1) the large range of capability in g levels included in the

purchase specifications (0.15g to 4.5g) and (2) the possibility of amplified

response at frequencies less than 33 Hz can result in unacceptable installa- tions. Except for cases where the valve operators are supported directly, no

basis can be found for considering piping and supports to be unaffected by the

change in frequency.

Although the information provided above deals with diaphragm valves manufac- tured by ITT Grinnell, there are indications that similar problems may exist in

valve/actuator assemblies sold by other manufacturers. The difference between

the original ITT Grinnell analysis and the test results illustrates the diffi- culty in analytically determining the natural frequency of the valve/actuator

assembly. To provide valid results, the analytical model must accurately

reflect the flexibility of the connection between the actuator and the valve.

This may require confirmatory experimental data.

Thus it appears that a

potential problem with the validity of valve qualification and piping analysis

can exist for cases where valve seismic qualification was performed by analyti- cal methods that were not confirmed by test results. This problem appears to

be more common for diaphragm valves that have a predicted natural frequency of

less than 55 Hz and that have heavy extended operators with flexibility in the

interface between the valve and the operator structure.

IN 86-XX

December , 1986 This information is being made available to licensees to provide insight to a

problem which may exist in systems with valves other than those specifically

addressed in the Part 21 notices from ITT Grinnell. No specific action or

written response is required by this information notice.

If you have any

questions about this matter, please contact the Regional Administrator of the

appropriate regional office or this office.

Edward L. Jordan, Director

Division of Emergency Preparedness

and Engineering Response

William F. Anderson, IE

(301)492-4819 Attachment:

List of Recently Issued IE Information Notices

• See Previous Concurrences

• DEPER:IE

WFAnderson

11/24/86

• DEPER:IE

AWDromerick

11/25/86

• PSB:IE

DGable

11/26/86 DE

RLBaer

Vf /86 D5 R

fIE

JERospnthal

12//86 D:DEPER:IE

ELJordan

12/

186

12 E

12/(1 /86

Attachment 1

IN 87-02

January 13, 1987

LIST OF RECENTLY ISSUED

IE INFORMATION NOTICES

Information

Date of

Notice No.

Subject

Issue

Issued to

87-01

86-110

86-109

86-108

86-107

86-106

86-105

86-104

RHR Valve Misalignment

Causes Degradation of

ECCS in PWRs

Anomalous Behavior of

Recirculation Loop Flow

in Jet Pump BWR Plants

Diaphragm Failure In Scram

Outlet Valve Causing Rod

Insertion

Degradation Of Reactor

Coolant System Pressure

Boundary Resulting From

Boric Acid Corrosion

Entry Into PWR Cavity With

Retractable Incore Detector

Thimbles Withdrawn

Feedwater Line Break

Potential For Loss Of

Reactor Trip Capability

At Intermediate Power

Levels

Unqualified Butt Splice

Connectors Identified In

Qualified Penetrations

1/6/87

12/31/86

12/29/86

12/29/86

12/29/86

12/16/86

12/19/86

12/16/86 All PWR

holding

All BWR

holding

All BWR

holding

All PWR

holding

facilities

an OL or CP

facilities

an OL or CP

facilities

an OL or CP

facilities

an OL or CP

All power reactor

facilities holding

an OL or CP

All power reactor

facilities holding

an OL or CP

All holders of OL or CP

for PWR or BWR

All pressurized and

boiling-water reactor

facilities holding

an OL or CP

86-14

Supplement 1

Overspeed Trips Of AFW, HPCI,

And RCIC Turbines

12/17/86

All power reactor

facilities holding

an OL or CP

86-103

Respirator Coupling Nut

Assembly Failures

12/16/86

All power reactor

facilities holding

an OL or CP and

fuel facilities

OL = Operating License

CP = Construction Permit

-confirmed by test results. This problem appears to be more common for valves

T

a predicted natural frequency

s than 55 nd

-

vy extended

operators with flexibility in the interface between the valve and the operator

structure.

This information is being made available to licensees to provide insight to a

problem which may manifest itself in systems with valves other than those

specifically addressed in the Part 21 notices from ITT Grinnell.

No specific action or written response is required by this information noticeA

p

en

If you have any questions about this matter, please contact the

Regional Administrator of the appropriate regional office or this office.

Edward L. Jordan, Director

Division of Emergency Preparedness

and Engineering Response

William F. Anderson, IE

(301)492-4819 Attachment:

List of Recently Issued IE Information Notices

D:DEPER:IE

ELJordan

11/

/86 DD:DEPER:IE

SASchwartz

11/

/86 DEPER:IE

WFAnderson

jj/--/86 M

DEIR-.

A rick

1

6 PSB:I FAY

DEPER:IE DEPER:IE

DGab 1- RLBaer

JERosenthal

11/;;/86 11/

/86

11/

/86