Information Notice 1989-81, Inadequate Control of Temporary Modifications to Safety-Related Systems
UNITED STATES
NUCLEAR REGULATORY COMMISSION
OFFICE OF NUCLEAR REACTOR REGULATION
WASHINGTON, D.C. 20555
December 6, 1989 NRC INFORMATION NOTICE NO. 89-81: INADEQUATE CONTROL OF TEMPORARY MODIFICATIONS
TO SAFETY-RELATED SYSTEMS
Addressees
All holders of operating licenses or construction permits for nuclear power
reactors.
Purpose
This information notice is intended to alert addressees to potential problems
resulting from inadequate control of temporary modifications to safety-related
systems in operating nuclear plants. It is expected that recipients will review
the information for applicability to their facilities and consider actions, as- ippropriate, to avoid similar problems.
However, suggestions contained in this
information notice do not constitute NRC requirements; therefore, no specific
action or written response is required.
Description of Circumstances
Several NRC design inspections of modifications to safety systems have revealed
instances in which the licensee's control of temporary modifications to safety- related systems was inadequate.
Specifically, these inspections revealed that
temporary modifications were not properly tracked, were not documented in a
timely fashion, and were not given a timely technical review. The following
findings from four inspections illustrate these concerns.
Zion Nuclear Power Station, Unit 1 (50-295/88-03)
The inspection team reviewed the licensee's "Temporary Alteration Program
for the installation of temporary modifications to the safety systems. This
program had the following weaknesses.
1. The program allowed immediate installation of a temporary modification
without a safety evaluation as required by 10 CFR 50.59. In accordance
with the procedural guidelines, detailed technical analysis was not
required for a temporary modification that was installed for less than
30 days. In addition, the program allowed the time frame for performing
the technical review to be extended to 60 days if the temporary modifi- cations were installed for use beyond 30 days. Thus, the modification
could remain technically unreviewed for 60 days, and if the modification
__NZ
IN 89-81 December 6, 1989 was cancelled within 30 days, it might never be analyzed.
Because an
assessment of the individual and synergistic effects of 30-day modifi- cations on the plant's safety systems was not performed, there was no
way of determining whether the safety of the plant had been compromised
by operating the systems with temporary modifications.
2.
The program did not provide an effective system for tracking the temporary
modifications. As a result, many temporary modifications remained in- stalled for a long time without being analyzed.
3. The program did not provide any directive for timely marking of the control
room copies of the controlled set of drawings to reflect a modified confi- guration of the system after the temporary modification had been installed.
Control room drawings that do not correctly reflect the as-built plant con- figuration could impair the capability of plant operators to troubleshoot
problems and to operate the plant safely.
Sequoyah Nuclear Plant, Units 1 and 2 (50-327/86-27 and 50-328/86-27)
Temporary modifications at the Sequoyah plant were performed through the
Temporary Alteration Control Form (TACF) program and associated administrative
procedures. The procedures addressed requirements for generation of follow-up
documentation, such as design change requests (DCRs), which include a required
detailed technical evaluation and also an evaluation to determine the possible
existence of an unreviewed safety question. The inspection team reviewed the
TACF program and a sample of the temporary modifications installed through the
TACF program. This program had the following weaknesses.
1. The TACF program did not require a DCR to be issued for a temporary modi- fication that was expected to be removed within 60 days of installation.
Therefore, such modifications were not given the detailed technical evalu- ation required by the DCR process. Such a modification could remain
unreviewed for 60 days, and if the modification was cancelled within 60
days, it might never be analyzed.
Because an assessment of the individual
and synergistic effects of 60-day modifications on the plant's safety
systems was not performed, there was no way of determining whether the
safety of the plant had been compromised by operating the systems with
2. The TACF program was routinely used to make permanent changes in the
plant. The decision to use this temporary modification program for
installation of permanent modifications was made at the discretion of
station personnel without adequate guidance. Sometimes the decision
was based on merely whether the Engineering Department would be able
to provide a modification package in a timely fashion. This approach
resulted in many installations of permanent modifications without appro- priate engineering evaluations.
IN 89-81 December 6, 1989 3. The TACF program did not have an effective system for tracking temporary
modifications. This weakness resulted in installation of many permanent
changes in plant safety systems without the proper safety evaluation and
associated documentation.
The program lacked instructions for updating
controlled copies of the control room drawings in a timely manner to
reflect installed temporary modifications. These.weaknesses resulted
in many errors in the control room drawings.
Enrico Fernii Atomic Power Plant, Unit 2 (50-341/89-200)
The inspection team reviewed the licensee's "Temporary Modification Programm
and a sample of the temporary modifications in detail. One modification was
installed during 1987 to silence a 'high drywell temperature" alarm that was
triggered by steam leaking from a valve in the drywell area. The design
temperature of the drywell was 135°F but the actual ambient temperature was
about 200OF because of the steam leak. Since the leak could not be fixed while
at power, the temporary modification raised the alarm setpoint to silence the
alarm. The review of this modification revealed that the licensee's evaluation
was inadequate. The effects of higher drywell ambient temperatures on various
design attributes, including environmental qualification of equipment in the
vicinity, density compensation for the filled instrument sensing lines of the
reactor instrumentation passing through the higher temperature area, and higher
voltage-drop in the cables and wires as a result of higher ambient temperatures, were not evaluated.
Calvert Cliffs Nuclear Power Plant, Units 1 and 2 (50-317/89-200 and
50-318/89-200)
The inspection team reviewed the licensee's "Temporary Modification Control"
procedure and a sample of the temporary modifications in detail. The team
found that the licensee's temporary modification program failed to ensure the
proper review of all modifications by the Plant Review Committee before their
installation into the plant, and that the program was not under sufficient
management oversight to minimize the number of temporary modifications in- stalled. The licensee's procedure permitted the shift supervisor to install
any temporary modification for up to 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> without a technical review or
a safety evaluation. Although the licensee's technical specifications required
that the Plant'Review Committee review all proposed changes or modifications to
plant systems or equipment affecting nuclear safety, the licensee's procedure
allowed the installation of temporary modifications-for up to 14 days with
interim approval from two SRO licensed individuals, one of whom must be a shift
supervisor. The temporary modification tracking system was not being kept
up to date.
Discussion:
It is important for licensees to evaluate the temporary modifications to safety- related systems before implementing these modifications. The evaluation includes
IN 89-81 December 6, 1989 verification that the modification will not have an adverse effect on the plant's
systems, equipment, or safety. Although licensees have generally met the NRC
requirements in 10 CFR 50.59, some licensees have not exercised an adequate level
of control for the activities associated with the temporary modifications to
safety-related systems, as illustrated in the above-identified deficiencies.
This information notice requires no specific action or written response.
If
you have any questions about the Information in this notice, please contact
the technical contacts listed below or the appropriate NRR project manager.
4s' 64.ZCow
Charles E. Rossi, Director
Division of Operational Events Assessment
Office of Nuclear Reactor Regulation
Technical Contacts:
E. V. Imbro, NRR
(301) 492-0954
S. V. Athavale, NRR
(301) 492-0974
J. R. Ball, NRR
(301) 492-0962 Attachment: List of Recently Issued NRC Information Notices
/
Q.
Attachment
December 6, 1989
Page 1of 1
LIST OF RECENTLY ISSUED
NRC INFORMATION NOTICES
Information
Date of
Notice No.
Subject
Issuance
Issued to
89-80
89-79 Potential for Water H~ammier,
Thermal Stratification, and
Steam Binding in H1gh--
Pressure Coolant Injection
Piping
Degraded Coatings and
Corrosion of Steel
Containment Vessels
Questionable Certification
of Material Supplied to
the Defense Department
by Nuclear Suppliers
12/1/89
12/1/89
11/22/89
All holders of OLs
or CPs for nuclear
power reactors.
All holders of OLs
All holders of OLs
or CPs for nuclear
power reactors.
I
89-56, Supp. 1
89-78
89-77
Failure of Packing Nuts
on One-Inch Uranium
Hexafluoride Cylinder
Valves
Debris in Containment
Emergency Sumps and
Incorrect Screen
Configurations
Biofouling Agent: Zebra
Mussel
Falsification of Welder
Qualifications for
Contractor Employees'
11/22/89
11/21/89
11/21/89
11/20/89
All NRC licensees
authorized to possess
and use source material
and/or special nuclear
material for the heating, emptying, filling, or
shipping of uranium
hexafluoride in 30-
and 48-inch diameter
cylinders.
All holders of OLs
All holders of OLs
or CPs for nuclear
power reactors.
All holders of OLs
or CPs for nuclear
power reactors.
89-76
89-75 OL = Operating License
CP - Construction Permit
IN 89-81 December 1, 1989 verification that the modification will not have an adverse effect on the plant's
systems, equipment, or safety. Although licensees have generally met the NRC
requirements in 10 CFR 50.59, some licensees have not exercised an adequate level
of control for the activities associated with the temporary modifications to
safety-related systems, as illustrated in the above-identified deficiencies.
This information notice requires no specific action or written response. If
you have any questions about the information in this notice, please contact
the technical contacts listed below or the appropriate NRR project manager.
Charles E. Rossi, Director
Division of Operational Events Assessment
Office of Nuclear Reactor Regulation
Technical Contacts:
E. V.
(301)
Imbro, NRR
492-0954 S. V.
(301)
J. R.
(301)
Athavale, NRR
492-0974 Ball, NRR
492-0962 Attachment:
List of Recently Issued NRC Information Notices
- SEE PREVIOUS CONCURRENCES
D/DOEA:NRR
CERossi
11/1 2/89
- SC/RSIB:DRIS:NRR
EVImbro
10/18/89
- C/OGCB: DOEA:NRR*RPB:ARM
CHBerlinger
TechEd
11/22/89
11/21/89
- C/RSIB:DRIS:NRR*D/DRIS:NRR
WDLanning
BKGrimes
10/18/89
11/07/89
- OGCB:DOEA:NRR
PCWen
10/19/89
- RSIB:DRIS:NRR
SVAthavale
10/18/89
IN 89-xx
November xx, 1989 This information notice requires no specific action or written response. If
you have any questions about the information in this notice, please contact one
of the technical contacts listed below or the appropriate NRR project manager.
Charles E. Rossi, Director
Division of Operational Events Assessment
Office of Nuclear Reactor Regulation
Technical Contacts:
E. V.
(301)
Imbro, NRR
492-0954 S. V.
(301)
J. R.
(301)
Athavale, NRR
492-0974 Ball, NRR
492-0962 Attachment:
List of Recently Issued NRC Information Notices
Document Name:
- SEE PREVIOUS CONCURN
INFO NOTICE - WEN, ATHAVALE
!ENCES
D/DOEA:NRR
C/ikOB:DOEA:NRR REAwRM
CERossi
CHBerlinger
Tfi
11/ /89
11/WJ/89
11/101/89 DRIS:NRR *SC/RSIB:DRIS:NRR *C/RSIB:DRIS:NRR*D/DRIS:NRR
iavale
EVImbro
WDLanning
BKGrimes
3/89
10/18/89
10/18/89
11/07/89
- OGCB:DOEA:NRR
PCWen
10/19/89
- RSIB:
SYAt9 lo/lE
IN 89-xx
- -
November xx, 1989
Page 4 of
No specific action or written response Is required by this information
notice. If you have any questions about this matter, please contact one of
the technical contacts listed below or the appropriate NRR project manager.
Charles E. Rossi, Director
Division of Operational Events Assessment
Office of Nuclear Reactor Regulation
Technical Contacts:
E. V.
(301)
Iibro, NRR
492-0954 S. V.
(301)
Athavale, NRR
492-0974
J. R. Ball, NRR
(301) 492-0962 Attachment: List of Recently Issued NRC Information Notices
- See previous concurrence
- OGCB:DOEA:NRR
PCWen
10/19/89
- RSIB:DRIS:NRR
SYAthavale
10/18/89
- SC:RISB:DRIS:NRR
EVImbro
10/18/89
- C:RSIB:DRIS:NRR
MDLanning
10/18/89 Y: NRR
mes
/89 TECH ED
11/
/89 C:OGCB:DOEA:NRR
CHBerlinger
11/
/89 D:DOEA:NRR
CERossi
11/
/89
.
.-
IN 89-xx
October xx, 1989
Page 3 of
Fermi Nuclear Plant, Unit 2 (50-341/89-200)
The inspection team reviewed the licensee's 'Temporary Modification Program"
and a sample of the temporary modifications in detail. One modification was
installed during 1987 to silence a "high drywell temperature' alarm that was
triggered by steam leaking from a valve in the drywell area. The design
temperature of the drywell was 1350F buty the actual ambient temperature was
about 200OF because of the steam leak. Since the leak could not be fixed while
at power, the temporary modification raised the alarm setpoint to silence the
alarm. The review of this modification revealed that the licensee's evaluation
was inadequate. The effects of higher drywell ambient temperatures on various
design attributes including environmental qualification of equipment in the
vicinity, density compensation for the filled instrument sensing lines of the
reactor instrumentation passing through the higher temperature area, and higher
voltage drop in the cables and wires as a result of higher ambient temperatures
were not evaluated.
Discussion:
It is important for licensees to evaluate the temporary modifications to
safety-related systems before implementing them. The evaluation Includes
verification that the modification will not have an adverse effect on the
plant's systems, equipment, or safety. Although licensees have generally met
the NRC requirements in 10 CFR 50.59, some licensees have not exercised an
adequate level of control for the activities associated with the temporary
modifications to safety-related systems, as illustrated in the above- identified deficiencies.
No specific action or written response is required by this information
notice.Etf you have any questions about this matter, please contact one of
the technical contacts listed below or the appropriate NRR project manager.
Charles E. Rossi, Director
Division of Operational Events Assessment
Office of Nuclear Reactor Regulation
Technical Contacts:
E.V. Imbro, NRR
(301)492-0954
S.V. Athavale, NRR
(301)492-0974 Attachment: List of Recently Issued NRC Information Notices
0X&G.2EA:NRR RS iS:NRR SCARiSB:DRIS:NRR
C:RSIB:
R
D:DRIS:NRR
PCWen
SVAthavale
EVImbro
MDLanning z
BKGrimes
10/ 1' /89
10/1Z /89
10/9*p /89
10/ /IV /8 fl
'
10/
/89 TECH ED
C:OGCB:DOEA:NRR
D:DOEA:NRR
CHBerlinger
CERossi
10/
/89
10/
/89
10/
/89