Information Notice 1990-77, Inadvertent Revoval of Fuel Assemblies from the Reactor Core

Inadvertent Revoval of Fuel Assemblies from the Reactor Core

ML031130163
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
Issue date:	12/12/1990
From:	Rossi C Office of Nuclear Reactor Regulation
To:
References
IN-90-077, NUDOCS 9012060205
Download: ML031130163 (9)

I

UNITED STATES

NUCLEAR REGULATORY COMMISSION

OFFICE OF NUCLEAR REACTOR REGULATION

WASHINGTON, D.C. 20555 December 12, 1990

NRC INFORMATION NOTICE NO. 90-77: INADVERTENT REMOVAL OF FUEL ASSEMBLIES

FROM THE REACTOR CORE

Addressees

All holders of operating licenses or construction permits for pressurized- water reactors (PWRs).

Purpose

This information notice is intended to alert addressees to potential problems

pertaining to the removal of nuclear fuel from the reactor core. 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 do not

constitute NRC requirements; therefore, no specific action or written

response Is required.

Description of Circumstances

On October 4, 1990, Indian Point Nuclear Generating Unit 3 was in a refuel- ing outage. The licensee was removing the upper core support structure

(upper internals) from the reactor vessel in preparation for refueling the

core. Upon initiating a lateral move of the upper core support structure, crane movement was stopped upon the discovery that two peripheral fuel

assemblies were attached to the bottom of the upper core plate, which is

part of the upper internals package. An underwater camera inspection had

been conducted after vertically lifting the upper core support structure

from the reactor vessel. This inspection was prompted by earlier analysis

of noise diagnostics data, confirming the existence of a loose part which

resembled a fuel assembly locating pin in the steam generator channel head.

Due to poor camera location and lighting, the attached fuel assemblies were

not recognized during the initial camera inspection.

The licensee's fuel assembly retrieval procedure developed to facilitate

their recovery included: (1) performing a static lift (no lateral movement)

of the upper internals package until the fuel assemblies were approximately

1 foot above the vessel flange, (2) rotating the upper internals package so

that the fuel assemblies would pass over the cavity seal one at a time, and

(3) positioning the assemblies such that they could be lowered into specially

fabricated steel baskets, which were located in the deep end of the refueling

cavity. During retrieval activities, one of the assemblies inadvertently

dropped into its basket when the brakes on the overhead crane were applied

with the assemblies positioned over their baskets. The licensee lowered and

9012000 4

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I

IN 90-77 December 12, 1990 freed the remaining assembly without incident. No radiological release

or breach of fuel integrity resulted from dropping the fuel assembly.

Discussion:

The licensee was using a 350,000 lb-capacity polar crane with a Dillon load

cell to lift the upper core internals package (weighing approximately

119,800 lbs). The suspended fuel-assemblies together weighed approximately

2600 lbs. During the lift, the licensee did not detect the additional weight

because the weight of the upper internals (with suspended fuel assemblies)

was within the maximum allowable weight of 125,800 lbs, as specified by the

licensee's refueling procedure.

Each of the two assemblies were attached to the upper core plate by bent fuel

assembly guide pins as shown in Attachment 1. These guide pins extend down- ward from the upper core plate and insert into two holes in the upper nozzle

of the fuel assembly when the upper core internals structure is properly

aligned over the top of the core. For each of the suspended fuel assemblies, the licensee found that one guide pin was bent and not inserted into the top

nozzle hole (upper nozzle S-hole on Attachment 1) of the fuel assembly, with

the other guide pin-bent and wedged into the assembly. In this condition, the guide pin suspended the assembly at an angle of approximately 7 degrees.

The licensee has determined that the fuel assembly guide pins were damaged

during the previous refueling outage when the upper internals package was

being removed from the upper internals storage stand.

Similar problems involving suspended fuel assemblies have occurred previously.

Information Notice 86-58, 'Dropped Fuel Assembly," describes a similar

situation at the Haddam Neck Generating Station in which the licensee inad- vertently lifted an assembly when removing the upper internals. In this

situation, the assembly dropped 2 to 4 feet onto the reactor core when the

upper internals were moved laterally. The dropped assembly and the two

assemblies it impacted were damaged; however, no radiological release occurred.

Another similar event occurred at the Palisades Nuclear Power Stationj(a

Combustion-Engineering plant) on September 3, 1988. At Palisades, the

licensee was removing the upper guide structure (UGS) from the vessel and

discovered a fuel bundle attached to the bottom. The licensee freed the fuel

bundle using a J-hook manipulated by a worker supported in a JIB crane while

the fuel bundle was suspended over the reactor core. The-root cause of the

fuel bundle becoming attached to the UGS was attributed to the bundle adhering

to the UGS bundle guide pins.

Other licensees have identified fuel assembly guide pins that were bent for

a variety of reasons. At Byron Station, Unit 2, on October'8, 1990, the

licensee inadvertently bent approximately 8 guide pins due to an error of a

polar crane floor director. The crane floor director gave a hand signal to

lower the upper internals package prematurely, while approximately 1/4 of

the upper internals were still over the upper internals storage stand. As a

result, the upper internals package impacted the storage stand and bent the

guide pins.

IN 90-77 December 12, 1990 Licensees may wish to consider reviewing their procedures and equipment

prior to performing activities which may lead to inadvertent damage to fuel

assembly guide pins and inspecting the guide pins before reinstallation of

the upper internals package into the reactor vessel. When reviewing

their procedures (to assure the ability of the reactor cavity seal to

withstand the mechanical, thermal, and radiation impacts from a dropped fuel

assembly) licensees may also wish to consider the need to carefully inspect

the upper core support structure as it is initially raised from the reactor

vessel to ensure that no core components are suspended.

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 NRR project manager.

46Mar esi- . Ro , D rector

Division of Operational Events Assessment

Office of Nuclear Reactor Regulation

John Thompson, NRR

(301) 492-1171 Attachments:

1. Indian Point 3 Detailed View Showing Suspended

Fuel Assembly from Bottom of Upper Internals

Package

2. List of Recently Issued NRC Information Notices

Attachment 1 IN 90-77 December 12, 1990 IHOLD DOWN SPRING

UPPER CORE PLATE

UPPER NOZZLE

S-HOLES

INDIAN POINT 3 Detailed View Showing Suspended Fuel Assembly from Bottom

of Upper Internals Package

At; hment 2 IN 90-77 December 12, 1990

Page I of I

LIST OF RECENTLY ISSUED

NRC INFORMATION NOTICES

Information Date of

Notice No. Subject Issuance Issued to

88-23, Potential for Gas Binding of 12/10/90 All holders of OLs or

Supp. 3 High-Pressure Safety Injection CPs for pressurized- Pumps During A Loss-Of-Coolant water reactors (PWRs).

Accident

90-76 Failure Of Turbine Overspeed 12/7/90 All holders of OLs or

Trip Mechanism Because Of CPs for nuclear power

Inadequate Spring Tension reactors.

90-75 Denial Of Access To Current 12/5/90 All Michigan holders

Low-Level Radioactive Waste of NRC licenses.

Disposal Facilities

90-74 Information on Precursors To 12/4/90 All holders of OLs or

Severe Accidents CPs for nuclear power

reactors.

90-73 Corrosion Of Valve-To- 11/29/90 All holders of OLs or

Torque Tube Keys In CPs for nuclear power

Spray Pond Cross Connect reactors.

Valves

90-72 Testing of Parallel Disc 11/28/90 All holders of OLs or

Gate Valves In Europe CPs for nuclear power

reactors.

90-71 Effective Use of Radi- 11/6/90 All KRC licensees

ation Safety Committees authorized to use by- to Exercise Control Over product material for

Medical Use Programs medical purposes.

90-70 Pump Explosions Involving 11/6/90 All uranium fuel

Ammonium Nitrate fabrication and

conversion facilities.

90-38, License and Fee Require- 11/6/90 All fuel facility and

Supp. 1 ments for Processing Fin- materials licensees.

ancial Assurance Submittals

for Decommissioning

89-30, High Temperature Environ- 11/1/90 All holders of OLs

Supp. 1 ments At Nuclear Power or CPs for nuclear

Plants power reactors.

OL = Operating License

CP = Construction Permit

IN 90-77 December 12, 1990 Licensees may wish to consider reviewing their procedures and equipment

prior to performing activities which may lead to inadvertent damage to fuel

assembly guide pins and inspecting the guide pins before reinstallation of

the upper internals package into the reactor vessel. When reviewing

their procedures (to assure the ability of the reactor cavity seal to

withstand the mechanical, thermal, and radiation impacts from a dropped fuel

assembly) licensees may also wish to consider the need to carefully inspect

the upper core support structure as it is Initially raised from the reactor

vessel to ensure that no core components are suspended.

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 NRR project manager.

Original Signed by

Charles E Rossi

Charles E. Rossi, Director

Division of Operational Events Assessment

Office of Nuclear Reactor Regulation

John Thompson, NRR

(301) 492-1171 Attachments:

1. Indian Point 3 Detailed View Showing Suspended

Fuel Assembly from Bottom of Upper Internals

Package

2. List of Recently Issued NRC Information Notices

See previous concurrences.

OFC  :*OEAB:DOEA :*SL:OEAB:DOEA :*D:PD1-1  :*RI  :*C:OEAB:DOEA:*RPB:ADM

NAME :JThompson :DCFischer :RCapra :PWEselgroth :AChaffee :Tech Ed

DATE :11/19/90 :11/11/90 :11/21/90 :11/21/90 :11/21/90 :11/12/90

OFC  :*D:DST:NRR :*RI  :*RI  :*C:CGCB:DOEA:NRR;

NAME :ACThandani :WHodges :BKEapen :CBerlinger

DATE :11/27/90 :11/27/90 :11/27/90 :12/03/90 12/7/90 -

OFFICIAL DOCUMENT NAME: IN 90-77

IN 9O-XX

December XX, 1990 Licensees may wish to carefully review their procedures and inspect equip- ment prior to performing activities which may lead to inadvertent damage to

fuel assembly locating pins, and inspect the locating pins before reinstal- lation of the upper internals package into the reactor vessel. The proce- dures to assure the ability of the reactor cavity seal to withstand the

mechanical, thermal, and radiation impacts from a dropped fuel assembly may

also need careful review. in addition, licensees may wish to carefully

inspect the upper core support structure as it is initially raised from the

reactor vessel to ensure that no core components are suspended.

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 NRR project manager.

Charles E. Rossi, Director

Division of Operational Events Assessment

Office of Nuclear Reactor Regulation

John Thompson, NRR

(301) 492-1171 Attachments:

1. Figure of fuel assembly showing locating pins

2. List of Recently Issued NRC Information Notices

See previous concurrences.

OFC  :*OEAB:DOEA :*SL:OEAB:DOEA :*D:PD1-1  :*RI  :*C:OEAB:DOEA:*RPB:ADM

NAME :JThompson :DCFischer :RCapra :PWEselgroth :AChaffee :Tech Ed

DATE :11/19/90 :11/1 :11/21/90 :11/21/90 :11/21/90 :11/12/90

OFC  :*D:DST:NRR :COGb r N<:D:DEA:NRR

NAME :ACThandani :Ceinr :ERossi

DATE :11/27/90 :12 90 :12/ /90

---

-__

___________ ______________ -----------

OFFICIAL DOCUMENT NAME: INDIANPT

IN 90-XX

November XX, 1990 while the upper internals were being moved back to the reactor vessel. The

hand signal was given prematurely, with approximately 1/4 of the upper

internals still over the upper internals support stand. As a result, the

upper internals package impacted the support stand, bending the locating pins.

Locating pins may also become bent when the upper Internals package is

positioned onto the support stand. If there is little space between the

locating pins and the refueling cavity floor, debris on the cavity floor under

the upper internals stand can also bend the locating pins.

Licensees may wish to carefully review their procedures and inspect equipment

prior to performing activities which may lead to inadvertent damage to fuel

assembly locating pins, and inspect the locating pins before reinstallation

of the upper internals package into the reactor vessel. In addition, licensees may wish to carefully inspect the upper core support structure as

it is initially raised from the reactor vessel to ensure that no core

components are suspended.

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 NRR project manager.

Charles E. Rossi, Director

Division of Operational Events Assessment

Office of Nuclear Reactor Regulation

Technical Coni:act: John Thompson, NRR

(301) 492-1171 Attachments: (1) Figure of fuel assembly showing locating pins

(2) List of Recently Issued NRC Information Notices

See previous concurrences.

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OFFICIAL DO UMENT NAME: INDIANPT