Information Notice 1989-06, Bent Anchor Bolts in Boiling Water Reactor Torus Supports

Bent Anchor Bolts in Boiling Water Reactor Torus Supports

ML031180498
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, 05000000, Zimmer, Fort Saint Vrain, Shoreham, Satsop, Trojan, Atlantic Nuclear Power Plant
Issue date:	01/24/1989
From:	Rossi C Office of Nuclear Reactor Regulation
To:
References
IN-89-006, NUDOCS 8901170031
Download: ML031180498 (7)

UNITED STATES

NUCLEAR REGULATORY COMMISSION

OFFICE OF NUCLEAR REACTOR REGULATION

WASHINGTON, D.C. 20555 January 24, 1989 NRC INFORMATION NOTICE NO. 89-06: BENT ANCHOR BOLTS IN BOILING WATER

REACTOR TORUS SUPPORTS

Addressees

All holders of operating licenses or construction permits for boiling water

reactors (BWRs) with Mark I steel torus shells.

Purpose

This information notice is being provided to alert addressees to the discovery

of bent anchor bolts in BWR torus shell supports. It is expected that recipi- ents will review the information for applicability to their facilities and

consider actions, as appropriate, to avoid similar problems. However, sugges- tions contained in this information notice do not constitute NRC requirements;

therefore, no specific action or written response is required.

Description of Circumstances

During recent NRC inservice inspections (50-321/88-03 and 50-366/88-03) at

E. I. Hatch Nuclear Plant, inspectors found a rock bolt anchoring a torus shell

support bent about 3/4 inch. The NRC requested that the Georgia Power Company

(GPC or licensee) perform a detailed survey of all torus anchor bolts in the

E. I. Hatch Plant, Units 1 and 2, and determine the extent of bolt distortions.

The licensee found 190 bolts in Unit 1 bent from 1/8 inch to 1 inch, with 45 of the bolts bent in excess of 1/2 inch. In Unit 2, the bolt distortions were

not as severe.

The subject rock anchor bolts were added to the torus supports to accommodate

the vertical torus hydrodynamic loads that were identified in the 1970s during

the Mark I containment systems review. The bolts were installed in slotted

holes in the column support bases to allow for some lateral movement of the

supports while resisting vertical hydrodynamic loads. However, the licensee

believes that at the E. I. Hatch Plant the torus column supports experienced

unexpected lateral displacements due to weld induced radial shrinkage of the

torus as a result of the Mark I program modifications performed several years

ago. These modifications consisted of welding T-stiffeners, saddle overlays, and conical web plates to the torus shell. The shrinkage of the welds resulted

in excessive radial movement of the torus and the torus supports. The excessive

radial displacement of the torus supports is believed to have caused the edges

of the slotted holes in the column support bases to push against the anchor bolts

and to eventually bend them.

8901170031 Z. ff_/C

IN 89-06 January 24, 1989 The licensee has performed an evaluation on the load capabilities of the bolts

using 3/4 inch deflections as the criterion and found that their capacities have

decreased from 310 kips to 230 kips. The licensee has not completed the evalu- ation on the bolt load carrying capacity using 1 inch deflections. On the basis

of preliminary evaluations, the licensee concludes that the torus is adequately

anchored to accommodate anticipated hydrodynamic loads.

Discussion:

Although rock anchor bolt distortions may not immediately affect plant operations, the NRC staff considers such distortions to-be significant since the bolt load

capabilities may be greatly reduced, and the bolts may crack and break if verti- cal hydrodynamic loads are applied. Anchor bolt distortions, if excessive and

not corrected, may lead to the fracture of the torus and may jeopardize contain- ment integrity.

There are a number of factors, ranging from temperature changes, methods and

sequence of construction, design of the column base supports, and type and

magnitude of loads applied, that can influence the movement of the torus

supports. Depending on the allowances made 'for such movement in the design

of the slotted holes in the support bases, the anchor bolts may be distorted

by various means. In view of this fact, it is possible that varying degrees

of anchor bolt distortions may exist at different nuclear power plants. Ac- cordingly, addressees may wish to inspect and evaluate the conditions of the

torus supports at their -plants to determtne-1fany-pr-W-emM5-tm-to those -

described above exist and to assure that the structural integrity of the torus

shell is being maintained.

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 techni- cal contacts listed below or the Regional Administrator of the appropriate

regional office.

Charles E. Rossi, Director

Division of Operational Events Assessment

Office of Nuclear Reactor Regulation

Technical Contacts: Chen P. Tan, NRR

(301) 492-0829 Jaime Guillen, NRR

(301) 492-1170

Attachment: List of Recently Issued NRC Information Notices

IN 89-06 January 24, 1989 The licensee has performed an evaluation on the load capabilities of the bolts

using 3/4 inch deflections as the criterion and found that their capacities have

decreased from 310 kips to 230 kips. The licensee has not completed the evalu- ation on the bolt load carrying capacity using 1 inch deflections. On the basis

of preliminary evaluations, the licensee concludes that the torus is adequately

anchored to accommodate anticipated hydrodynamic loads.

Discussion:

Although rock anchor bolt distortions may not immediately affect plant operations, the NRC staff considers such distortions to be significant since the bolt load

capabilities may be greatly reduced, and the bolts may crack and break if verti- cal hydrodynamic loads are applied. Anchor bolt distortions, if excessive and

not corrected, may lead to the fracture of the torus and may jeopardize contain- ment integrity.

There are a number of factors, ranging from temperature changes, methods and

sequence of construction, design of the column base supports, and type and

magnitude of loads applied, that can influence the movement of the torus

supports. Depending on the allowances made for such movement in the design

of the slotted holes in the support bases, the anchor bolts may be distorted

by various means. In view of this fact, it is possible that varying degrees

of anchor bolt distortions may exist at different nuclear power plants. Ac- cordingly, addressees may wish to inspect and evaluate the conditions of the

torus supports at their plants to determine if any problems similar to those

described above exist and to assure that the structural integrity of the torus

shell is being maintained.

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 techni- cal contacts listed below or the Regional Administrator of the appropriate

regional office.

Charles E. Rossi, Director

Division of Operational Events Assessment

Office of Nuclear Reactor Regulation

Technical Contacts: Chen P. Tan, NRR

(301) 492-0829 Jaime Guillen, NRR

(301) 492-1170

Attachment: List of Recently Issued NRC Information Notices

• SEE PREVIOUS PAGE FOR CONCURRENCE

D}OUE ~ '*C/OGCB:DOEA:NRR

GERodfL-' HBerlinger

01#/789 01/12/89

• OGCB:DOEA:NRR *ESGB:DEST:NRR *C/ESGB:DEST:NRR *EA/DEST:NRR*PPMB:ARM

JGuillen CPTan GBagchi JRichardson TechEd

01/12/89 12/22/88 12/22/88 12/28/88 12/22/88

IN 89-XX

January xx, 1989 The licensee has performed an evaluation on the load capabilities of the bolts

using 3/4 inch deflections as the criterion and found that their capacities had

decreased from 310 kips to 230 kips. The licensee has not completed its

evaluation on the bolt load carrying capacity using 1 inch deflections. -On-the-

12scA Cv'o baeas4.--of preliminary evaluations, the licensee concludes that the torus is

adequately anchored to accommodate anticipated hydrodynamic loads.

Discussion:

Although the rock anchor bolt distortions do not immediately affect plant

operations, the NRC staff considers such distortions to be significant since

the bolt load capabilities may be greatly reduced and the bolts may crack and

break if vertical hydrodynamic loads are applied. The anchor bolt distortions, if excessive and not corrected, may lead to the fracture of the torus and may

jeopardize containment integrity.

There are a number of factors, ranging from temperature changes, methods and

sequence of construction, design of the column base supports, and type and

magnitude of loads applied, that can influence the movement of the torus

supports. Depending on the allowances made for such movement in the design of

the slotted holes in the support bases, the anchor bolts may be distorted by

various means. In view of this fact, it is possible that in some plants the

anchor bolt distortions may be more severe than those identified at the Hatch

Nuclear Plant. Accordingly, addressees may wish to inspect and evaluate the

conditions of the torus supports at their plants to determine if any problems

similar to those described above exist and to assure that the structural

integrity of the torus shell is being maintained.

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 techni- cal contacts listed below or the Regional Administrator of the appropriate

regional office.

Charles E. Rossi, Director

Division of Operational Events Assessment

Office of Nuclear Reactor Regulation

Technical Contacts: Chen P. Tan, NRR

(301) 492-0829 Jaime Guillen, NRR

(301) 492-1170

Attachment: List of Recently Issued NRC Informa tion Notices M -tgt

D/DOEA:NRR C/ :NRR

tee. parCC' \ OW Cvcxo 5 CERossi CHBerlinger

01/ /89 01 -489

0O :NRR aSGB:DEST:NRR t/ESGB:DEST:NRR '*AD/DEST:NRRIP-B:ARM

JGu ten CPTan GBagchi JRichardson TechEd

01/ /89 01/ /89 01/ /89 01/ /89

- 2 -

capabilities may be greatly reduced and the bolts may crack and break if an up- lift force is applied. The rock bolt distortions, if excessive and not corrected, may lead to the fracture of the torus and may jeopardize containment integrity.

As a result of the Mark I containment program that identified the uplift force

on the torus, the anchor bolts were added to the column support bases which

originally consisted of steel lubrite bearing plates. The bolts were installed

with slotted holes in the steel plates to allow for the unrestrained lateral

movement of the supports while resisting the uplift forces. However, at the

E. I. Hatch Plant, it appears that the support movements resulting from weld

strinkage has been greater than that considered during design.

There are a number of factors, ranging from temperature changes, methods and

sequence of construction, design of the column base supports, and type and

magnitude of loads applied, that can influence the movement of the supports.

Depending on the allowances made for such movement in the design of the slotted

holes in the steel bearing plates, the rock bolts may be distorted by various

means. In view of this fact, it is possible that in some plants the rock bolt

distortions may be more severe than those in other plants. Accordingly, addres- sees may wish to inspect and evaluate the condition of the torus supports at

their plants to determine if any problems similar to those described exist and

to assure themselves that the structural integrity of the torus shell is intact.

No specific action or written response is required by this information notice.

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

contact listed below or the Regional Administrator of the appropriate region

office.

Charles E. Rossi, Director

Division of Operational Events Assessment

Office of Nuclear Reactor Regulation

cc: V. Stello L. Shao DISTRIBUTION:

T. E. Murley J. Richardson ESGB R/F

W. Russell G. Bagchi Central File

M. Ernst C. H. Berlinger

A. Davis J. Guillen

R. Martin B. Callure

J. Martin C. P. Tan

Chen P. Tan, NRR

(301) 492-0829 Jaime Guillen, NRR

(301) 492-1170

OFC :ESGB:DESTt :*Tech Editor :ESGB/DEST# :EAD/ C/DOEA :OGCB/DOEA :DOEA/NRR

---

____ SL__ ____________

_ ____________ _____

---

NAME :CPTan :BCallure :GBagchi :JRich e son :JGuillen :CHBerlinger:CERossi

DATE :12/?wtf88 :12&-t88 :12hz.X88 :12/ - 88 :12/ /88 :12/ /88 :12/ /88 OFFICIAL RECORD COPY See- PoutvioWS ACeo>- t,. 11J,

- 2 -

capabilities may be greatly reduced and the bolt may crack and break if an up- lift force is applied. The rock bolt distortions, if excessive and not corrected, may lead to the fracture of the torus and may jeopardize containment integrity.

As a result of the Mark I containment program that identified the uplift force

on the torus, the anchor bolts were added to the column support base that

originally consisted of steel lubrite bearing plates. The bolts were installed

with slotted holes in the steel plates so that movement of the support is unre- strained although capable of resisting the uplift forces. However, at the

E. I. Hatch Plant, it appears that the actual movement has been greater than

that considered during design.

There are a number of factors, ranging from temperature changes, methods and

sequence of construction, design of the column base supports, and type Bn'd

magnitude of loads applied, that can influence the movement of the supports.

Depending on the allowances made for such movement in the design of/the slotted

holes in the steel bearing plates, the rock bolts may be distort by various

means. In view of this fact, it is possible that in some plan the rock bolt

distortions may be more severe than those in other plants. cordingly, addres- sees may wish to inspect and evaluate the condition of the orus supports at

their plants to determine if any problems similar to thos described exist and

to assure themselves that the structural integrity of te torus shell is intact.

No specific action or written response is required this information notice.

If you have any questions about this matter, plea contact the technical

contact listed below or the Regional Administrat of the appropriate region

office.

Cha es E. Rossi, Director

D ision of Operational Events Assessment

ffice of Nuclear Reactor Regulation

cc: V. Stello L. Shao DISTRIBUTION:

T. E. Murley J. Richar son ESGB R/F

W. Russell G. Bagc Central File

M. Ernst C. H. Xerlinger

A. Davis J. G len

R. Martin B. allure

J. Martin C P. Tan

Technical Contact:

hen P. Tan, NRR

(301) 492-0829 Jaime Guillen, NRR

(301) 492-1170

OFC :ESGB:DEST  :*Tg h Editor :ES B/ EST :EAD/DEST:NRR:OGC/DOEA :OGCB/DOEA :DOEA/NRR

- -----

NAME :CPTan r7 Callure  : Ba hi :JRichardson :JGuillen :CHBerlinger:CERossi

DATE :12/1v/88 :12/.2488 -I:12/V88 :12/ /88 :12/ /88 :12/ /88 :12/ /88 OFFICIAL RECORD COPY

- Attachment

IN 89-06 January 24, 1989 LIST OF RECENTLY ISSUED

NRC INFORMATION NOTICES

Information Date of

Notice No. Subject Issuance Issued to

89-05 Use of Deadly Force by 1/19/89 All holders of OLs

Guards Protecting Nuclear for nuclear power

Power Reactors Against reactors.

Radiological Sabotage

89-04 Potential Problems from 1/17/89 All holders of OLs

the Use of Space Heaters or CPs for nuclear

power reactors and

test and research

reactors.

89-03 Potential Electrical 1/11/89 All fuel cycle and

Equipment Problems major nuclear materials

licensees.

89-02 Criminal Prosecution of 1/9/89 All holders of a

Licensee's Former President U.S. NRC specific

for

Intent

ional Safety license.

Violations

88-23, Potential for Gas Binding 1/5/89 All holders of OLs

Supp. 1 of High-Pressure Safety or CPs for PWRs.

Injection Pumps During a

Loss-of-Coolant Accident

89-01 Valve Body Erosion 1/4/89 All holders of OLs

or CPs for nuclear

power reactors.

88-46, Licensee Report of Defective 12/30/88 All holders of OLs

Supp. 2 Refurbished Circuit Breakers or CPs for nuclear

power reactors.

88- 101 Shipment of Contaminated 12/28/88 All holders of OLs

Equipment between Nuclear or CPs for nuclear

Power Stations power reactors.88-100 Memorandum of Understanding 12/23/88 All major nuclear

between NRC and OSHA materials licensees

Relating to NRC-licensed and utilities holding

Facilities (53 FR 43950, CPs and OLs.

October 31, 1988)

OL = Operating License

CP = Construction Permit