United States Nuclear Regulatory Commission - Protecting People and the Environment

ACCESSION #: 9510260001

INEL                                                      LOCKHEED MARTIN

                                      Lockheed Idaho Technologies Company
                                    P. O.  Box 1625 Idaho Falls, ID 83415

Idaho National Engineering Laboratory

September 19, 1995

Mr.  Thomas G.  Scarbrough, Project Officer
Division of Engineering
Office of Nuclear Regulatory Research
U.S.  Nuclear Regulatory Commission
Washington, DC 20555


References:    JCN A6857, "Equipment Operability (Mechanical)"
               R. Steele letter to Dr. G. H. Weidenhamer, "Isolation
               Valve Assessment (IVA) Software Error," RS-14-95,
               September 15, 1995

Dear Mr.  Scarbrough:

This letter continues an earlier report of a software error in the
Isolation Valve Assessment Software (IVA) Version 4.10 reported by R.
Steele in the referenced letter.  As you know, during a recent internal
assessment, we determined that a few selected results from IVA Version
4.10 coding used to assess the performance of motor-operated valves
(MOVs) appear to be incorrect.  We have notified all registered IVA users
of the error, but we cannot anticipate how they may have used IVA at a
particular facility.  Therefore, we have determined that we are not in a
position to identify any substantial 'Safety hazard for reporting under
10 CFR Part 21.  If an individual user identifies a safety noncompliance
in their application of the IVA software, we would expect them to notify
NRC under 10 CFR Part 21.

The following is a concise definition of the problem:

Identification of Basic Component

The error is in the Isolation Valve Assessment (IVA) Software, Version
4.10.  This error is restricted to that portion of the software code that
assesses MOV diagnostic test data for a gate valve in the opening only.

Mr.  Thomas G.  Scarbrough
September 19, 1995
Page 2

Discovery Date

The discovery date of this error was September 13, 1995.

Nature of Defect

A preliminary investigation indicates that there is an incorrect sign in
that portion of the IVA Software that sums the vertical force terms
acting on a gate valve disc during an opening test.  When used to
evaluate MOV diagnostic test data, the error may produce estimates for
disc factor that are too low.  If used in design-basis calculations, this
value could produce nonconservative estimates of the required valve stem
thrust needed to overcome design-basis conditions.

Equipment Affected

The error is isolated to the assessment of motor-operated gate valve
diagnostic test data for the opening direction.

Licensee Corrective Action

During the resolution of this issue, any Licensee should restrict the use
of IVA Version 4.10 to areas other than the assessment of diagnostic test
data for gate valve opening.  Any use of Version 4.10 to evaluate
diagnostic test data for gate valves in the opening direction should be
reevaluated using other methods.

If a Licensee identifies a safety noncompliance in their application of
the IVA software, they would be expected to notify NRC under 10 CFR Part

INEL Corrective Action

The INEL has notified users of IVA Version 4.10 of the error in the
opening test assessment section by letters dated September 15, 1995.
Further, the error will be corrected and the program reissued after

We are investigating how this error escaped the independent validation
and verification (V&V) of this program.  The V&V was conducted by an
independent design review committee and met all the requirements of ASME
Standard NQA-1-1994 quality plan and the NQA-2-1994, Part 2.7 software
quality control requirements.

Mr.  Thomas G.  Scarbrough
September 19, 1995
Page 3

Any questions or clarifications regarding this determination may be
directed to R. Steele, Jr. (208-526-6409) or J. C. Watkins (208-526-


R. G. Bennett, Manager
Nuclear Engineering Technologies Department


cc:  S.  F.  Armour, DOE-ID, MS 1219
     K.  G.  DeWall, LMIT, MS 3870
     Document Control Desk, USNRC
     J.  A.  Lake, LMIT, MS 3860
     D.  A.  Love, LMIT, MS 3591
     R.  Steele, Jr., LMIT, MS 3870
     J.  C.  Watkins, LMIT, MS 3870
     JCN File A6857
     R.  G.  Bennett File
     File Code 417


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