Information Notice 1993-72, Observations from Recent Shutdown Risk and Outage Management Pilot Team Inspections

From kanterella
(Redirected from Information Notice 1993-72)
Jump to navigation Jump to search
Observations from Recent Shutdown Risk and Outage Management Pilot Team Inspections
ML031070092
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, Three Mile Island, 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, Fort Saint Vrain, Shoreham, Satsop, Trojan, Atlantic Nuclear Power Plant  Entergy icon.png
Issue date: 09/14/1993
From: Grimes B
Office of Nuclear Reactor Regulation
To:
References
IN-93-072, NUDOCS 9309090243
Download: ML031070092 (8)


Ku

UNITED STATES

NUCLEAR REGULATORY COMMISSION

OFFICE OF NUCLEAR REACTOR REGULATION

WASHINGTON, D.C. 20555 September 14, 1993 NRC INFORMATION NOTICE 93-72: OBSERVATIONS FROM RECENT SHUTDOWN RISK AND

OUTAGE MANAGEMENT PILOT TEAM INSPECTIONS

Addressees

All holders of operating licenses or construction permits for nuclear power

reactors.

Purpose

The U.S. Nuclear Regulatory Commission (NRC) is issuing this information

notice to inform addressees of observations from recent shutdown risk and

outage management pilot team inspections. It is expected that recipients will

review the information for applicability to their facilities and consider

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

contained in this information notice are not NRC requirements; therefore, no

specific action or written response is required.

Background

Events that occurred during the past several years have caused the NRC staff

to be increasingly concerned about plant safety during shutdown operations.

The Diablo Canyon event of April 10, 1987, in which boiling of the reactor

coolant resulted from a loss of decay heat removal, highlighted the fact that

operation of a pressurized-water reactor with a reduced reactor coolant system

(RCS) inventory is a particularly sensitive condition. Based on its review of

that event, the staff issued Generic Letter 88-17, "Loss of Decay Heat

Removal," October 17, 1988, which requested that licensees address certain

generic deficiencies to improve safety during operations with a reduced RCS

inventory. More recently, Incident Investigation Team report, NUREG-1410,

"Loss of Vital ac Power and the Residual Heat Removal System During Mid-Loop

Operations at Plant Vogtle Unit 1 on March 20, 1990," emphasized the need for

risk management of shutdown operations. Discussions with foreign regulatory

organizations support NRC staff findings that the core-damage-frequency for

shutdown operations may be a substantial fraction of the total core-damage

frequency.

Description of Circumstances

Between December 1991 and April 1993, the NRC staff conducted five pilot team

inspections to assess the effectiveness of industry initiatives for improving

shutdown safety. The inspections were performed at Oconee Nuclear Station, Unit 2 [NRC Inspection Report (IR)50-270/91-202], Indian Point Nuclear

9309090243

- U 1?-.crn-9

3 .

IN 93-72 September 14, 1993 Generating Station, Unit 3 (IR 50-286/92-901), Diablo Canyon Nuclear Station, Unit 1 (IR 50-275/92-201), Prairie Island Nuclear Generating Plant, Units 1 and 2 (IR 50-282/92-201; 50-306/92-201), and Cooper Nuclear Station

(IR 50-298/93-201). Approximately one week of each inspection focused on

licensee pre-outage planning and control processes and 8 to 10 days focused on

licensee implementation of the outage.

In the pre-outage portion of the inspection, the inspectors evaluated the

following: (1) management involvement in and oversight of the outage planning

process, (2) planning and scheduling of outage activities, especially the

relationships between significant work activities and the availability of

electrical power supplies, decay heat removal systems, reactor coolant system

RCS inventory and containment integrity, (3) the process for developing

individual work packages to ensure coordination with other activities, and (4)

operator response procedures, contingency plans and training for mitigation of

loss of decay heat removal capability, loss of RCS inventory and loss of

electrical power sources during shutdown conditions.

The inspectors walked through procedures related to shutdown safety to

determine if the specified activities could be accomplished in the allotted

time frames and to verify that the procedures could be implemented considering

probable equipment availability. The inspectors reviewed training records on

outage procedures to determine if the training was adequate and that, when

appropriate, additional training was provided as the procedures were revised.

The inspectors also evaluated the probable effects of environmental conditions

such as temperature, steam and flooding on the performance of activities that

would be required to mitigate adverse shutdown events.

In the implementation portion of the inspection, the inspectors evaluated:

(1) the control of changes to the outage schedule, control of work activities, and control of system alignments, (2) the working relationships and

communication channels between operations, maintenance and other plant support

personnel, (3) the conduct of operations personnel both inside and outside of

the control room regarding awareness of plant status, control of plant

evolutions, response to alarms and other abnormal indications, (4) the

completeness and effectiveness of shift turnovers, (5) whether maintenance and

modification work was performed in accordance with current written and

approved procedures and appropriate post-maintenance testing was required and

performed, and (6) the adequacy of management involvement and oversight of the

conduct of the outage as it progressed.

Other areas observed were, plant housekeeping, normal and emergency plant

lighting, configuration control, radiological controls, equipment labeling and

status tagging, vital area access control, use of overtime and licensee

control of contractor work including contractor training and qualifications.

Discussion

In general, the inspectors found that licensees had instituted programmatic

changes developed from guidance contained in a Nuclear Management and

Resources Council document, NUMARC 91-06, "Guidelines for Industry Actions to

TV

IN 93-72 September 14, 1993 individual examples of

Assess Shutdown Management." The team inspectors found the inspectors

licensee failure to follow procedures but more importantly assessment for

identified two areas of more general concern: (1) risk

and (2)

pre-outage planning, emergent work and schedule changes, availability.

methodologies for equipment

implementation of defense-in-depth Specific details of

A general discussion of these areas is provided below.

above.

the findings are contained in the inspection reports referenced

and Schedule Changes

Risk Assessment for Pre-Outage Planning, Emergent Work

controls to

The inspectors found that licensees used various programmatic emergent work and

assess shutdown risk factors during initial outage planning, outage planning

schedule changes. Assessment methodologies used for initial availability to

ranged from following minimum guidelines for equipment outage activities.

performing a probabilistic risk assessment of scheduled the licensee in

The inspection team found that the risk assessment aided during the sched led

identifying activities that would be subject to high risk became less

outage. However, as the outage progressed, the risk assessment schedule occurreda

valid because it was not updated as changes to the outage

inspectors found that

In the areas of emergent work and schedule changes, the effect of \

three of the plants had a proceduralized process to assess the two plants relied

other

emergent work or schedule changes on plant risk. Theoperators to adjust the

on a functional review by planners, schedulers, and

schedule appropriately to reduce risk.

status boards or

The inspectors found that all of the plants maintained in tracking the

checklists in the control room to assist the operators

potential

configuration status of plant systems and to help identify

risk-significant activities.

Implementation of Defense-in-Depth for Equipment Availability

of defense-in-depth

The inspection teams found that licensee implementation industry guidelines for

for equipment availability was inconsistent. Although

that the criteria

declaring equipment "available" exist, the inspectors found of safety

an appropriate margin

for declaring equipment needed to ensure declaring that

"available" varied from licensee to licensee. For example, include ensuring that support systems

equipment was "available" did not always conditioning) were also

(e.g., cooling water and heating, ventilation and air

had been performed, equipment was

available. At times, after maintenance functional

listed as "available" without the benefit of a post-maintenance considered to be

test. The inspectors also found that some equipment was

as removal of clearances or realignment

"available" even though actions, such perform its function.

of valves, would be required before the equipment could

the team inspectors

In addition to the above concerns, at most of the plants restrictions

found examples of failures to comply with technical specification

to exceed overtime limits was

on overtime work in that management approval

inadequately documented.

K-,

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 contact listed below or the appropriate Office of Nuclear

Reactor Regulation (NRR) project manager.

Brian K. Grimes, Director

Division of Operating Reactor Support

Office of Nuclear Reactor Regulation

Technical contact: J.D. Wilcox, NRR

(301) 504-1262 Attachment: List of Recently Issued NRC Information Notices

RSIB:DRIL:NRR RSIB:DRIL:NRR AC/RSIB:DRIL:NRR D/DRIL:NRR

JDWilcox SSanders DNorkin CERossi

07/02/93 07/02/93 07/02/93 07/10/93 RPB:ADM OGCB:DORS:NRR C70MO:DORS:NRR D/DORS:NRR

NBeeson JLBirmingham iGHMarcus BKGrimes

08/10/93 08 /1/ 93 J9 PT

S/Al/93 09/ /93 RSIB
DRIL:NRR

PSKoltay

07/06/93

- IN 93-xx

September xx, 1993 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 contact listed below or the appropriate Office of Nuclear

Reactor Regulation (NRR) project manager.

Brian K. Grimes, Director

Division of Operating Reactor Support

Office of Nuclear Reactor Regulation

Technical contact: J.D. Wilcox, NRR

(301) 504-1262 Attachment: List of Recently Issued NRC Information Notices

  • SEE PREVIOUS CONCURRENCE
  • RSIB:DRIL:NRR *RSIB:DRIL:NRR *AC/RSIB:DRIL:NRR *D/DRIL:NRR

JDWilcox SSanders DNorkin CERossi

07/02/93 07/02/93 07/02/93 07/10/93

  • RPB:ADM *OGCB:DORS:NRR > C/OGCB:DORS:NRR D/DORS:NRR

NBeeson JLBirmingham GHMarcus/Wen BKGrimes

08/10/93 08/27/93 08/27/93 09/ /93

  • RSIB:DRIL:NRR

PSKoltay

07/06/93 DOCUMENT NAME: OUTAGEIN.JLB

'-vJ

IN 93-72 September 14, 1993 Based on the five pilot inspections, the NRC inspection teams concluded that

NRC actions and industry initiatives have increased licensee awareness of the

risk associated with shutdown and low power conditions. The inspection teams

found that licensees were aware of the necessity for ensuring that required

systems be available and of the need to maintain the capability of backup

equipment during an outage. However, the inspection teams found that licensee

interpretations of industry initiatives for addressing shutdown risk varied

greatly. This was demonstrated by the various licensee interpretations of

industry guidelines for declaring equipment "available."

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 contact listed below or the appropriate Office of Nuclear

Reactor Regulation (NRR) project manager.

Original signed by

Brian K.Grimes

Brian K. Grimes, Director

Division of Operating Reactor Support

Office of Nuclear Reactor Regulation

Technical contact: J.D. Wilcox, NRR

(301) 504-1262 Attachment:

List of Recently Issued NRC Information Notices

  • SEE PREVIOUS CONCURRENCE
  • RSIB:DRIL:NRR *RSIB:DRIL:NRR *AC/RSIB:DRIL:NRR *D/DRIL:NRR

JDWilcox SSanders DNorkin CERossi

07/02/93 07/02/93 07/02/93 07/1 dJ3 (qy

  • RPB:ADM *OGCB:DORS:NRR *C/OGCB:DORS:NRR

NBeeson JLBirmingham GHMarcus/Wen

08/10/93 08/27/93 08/27/93

  • RSIB:DRIL:NRR

PSKoltay

07/06/93 DOCUMENT NAME: 93-72.IN

IN 93-72 September 14, 1993 Based on the five pilot inspections, the NRC inspection teams concluded that

NRC actions and industry initiatives have increased licensee awareness of the

risk associated with shutdown and low power conditions. The inspection teams

found that licensees were aware of the necessity for ensuring that required

systems be available and of the need to maintain the capability of backup

equipment during an outage. However, the inspection teams found that licensee

interpretations of industry initiatives for addressing shutdown risk varied

greatly. This was demonstrated by the various licensee interpretations of

industry guidelines for declaring equipment "available."

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 contact listed below or the appropriate Office of Nuclear

Reactor Regulation (NRR) project manager.

C-

Brian K. Grimes, Director

Division of Operating Reactor Support

Office of Nuclear Reactor Regulation

Technical contact: J.D. Wilcox, NRR

(301) 504-1262 Attachment:

List of Recently Issued NRC Information Notices

KJ

Attachment

IN 93-72 September 14, 1993 LIST OF RECENTLY ISSUED

NRC INFORMATION NOTICES

Information Date of

Notice No. Subject Issuance Issued to

93-71 Fire at Chernobyl Unit 2 09/13/93 All holders of OLs or CPs

for nuclear power reactors.

93-70 Degradation of Boraflex 09/10/93 All holders of OLs or CPs

Neutron Absorber Coupons for nuclear power reactors.

93-69 Radiography Events at 09/02/93 All holders of OLs or CPs

Operating Power Reactors for nuclear power reactors

and all radiography

licensees.

93-68 Failure of Pump Shaft 09/01/93 All holders of OLs or CPs

Coupling Caused by for nuclear power reactors.

Temper Embrittlement

during Manufacture

92-16, Loss of Flow from the 08/23/93 All holders of OLs or CPs

Supp. 2 Residual Heat Removal for nuclear power reactors.

Pump during Refueling

Cavity Draindown

93-67 Bursting of High 08/16/93 All holders of OLs or CPs

Pressure Coolant for nuclear power reactors.

Injection Steam Line

Rupture Discs Injures

Plant Personnel

93-66 Switchover to Hot-Leg 08/16/93 All holders of OLs or CPs

Injection Following for pressurized water

A Loss-of-Coolant reactors.

Accident in Pres- surized Water Reactors

93-65 Reactor Trips Caused 08/13/93 All holders of OLs or CPs

by Breaker Testing for nuclear power reactors.

with Fault Protection

Bypassed

OL = Operating License

CP = Construction Permit