Information Notice 1990-08, KR-85 Hazards from Decayed Fuel

KR-85 Hazards from Decayed Fuel

ML031130307
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, Fort Saint Vrain, Shoreham, Satsop, Trojan, Atlantic Nuclear Power Plant
Issue date:	02/01/1990
From:	Rossi C E Office of Nuclear Reactor Regulation
To:
References
IN-90-008, NUDOCS 9001260198
Download: ML031130307 (7)

UNITED STATES NUCLEAR REGULATORY

COMMISSION

OFFICE OF NUCLEAR REACTOR REGULATION

WASHINGTON, D.C. 20555 February 1. 1990 NRC INFORMATION

NOTICE NO. 90-08: KR-85 HAZARDS FROM DECAYED FUEL

Addressees

All holders of operating

licenses or construction

permits for nuclear power reactors and holders of licenses for permanently

shutdown facilities

with fuel on site.

Purpose

This information

notice alerts addressees

to potential

problems resulting

from*the .accidental

release of Kr-85 from decayed fuel. It is expected that reci pients will review the Information

for applicability

to their facilities

and consider actions, as appropriate, to avoid similar problems.

However, sugges-tions co'ntained

in this information

notice do not constitute

NRC 'requirements;

therefore, no specific action or written response is required.Desripionof

Circumstances:

During the licensing

reviews for the Oconee independent

spent fuel storage Installation,, and in the decommissioning

of the La Crosse and Dresden Unit 1 power reactors, the NRC staff analyzed the radiological

hazards associated.with the gases In decayed spent fuel. The age of the nuclear power industry and the lack of a permanent

repository

for spent fuel have resulted in the accumulation

of decayed'spent

fuel.* Decayed spent fuel is manipulated

after long shutdowns

of operating

reactors, during spent fuel pool re-racking, during mo~vement

to alternate

reactor sites or independent

spent fuel storage instal-lations, and during decommissioning.

Analysis of hypothetical

accidents involving

decayed spent fuel has focused attention

on potential

difficulties

that'could

be associated

with the exposure of onsi1te personnel

to an accidental

release of Kr-85. IKr-85 is a noble gas fission product that is present in the gaps between the fuel pellets and the cladding.

It has a 10.76-year

half-life, and, as a result of the considerably

shorter half-lveso

ital l te gaseous fission products (1-129 being the exception, but in low abundance),, Kr-85 becomes Increasingly

the dominant nuclide in the accident source term for gap releases as decay times increase.

After 2 weeks of decay, Kr-85 is a significant

nuclide in the source term, and after 190 days of decay, it is the predominant

gaseous nuclide for a gap release. The unusual decay character- istics of K~r-85 give cause for focusing attention

on the onsite consequences

of a gap release from decayed fuel.,-9001260198

40--

IN 90-08 February 1, 1990 Discussion:

Kr-85 emits beta radiation

with a maximum energy of 0.67 MeY for 99.6 percent of the decays and 0.51 MeV gamma radiation.

for 0.4 percent of the decays. Conse-quently, direkt exposure to this gas would result in a dose to the skin approxi-mately 100 times the whole-body

dose. Analysis of the relative consequences (in terms of radiological

doses) of a cask-drop

accident as a function of decay time of the fuel is illustrated

in Figure 1. In the event of a serious accident involving

decayed spent fuel, protective

actions would be needed for personnel on site, while offsite doses (assuming

an exclusion

area radius of 1 mile from the plant site) would be well below the Environmental

Protection

Agency's Protective

Action Guides. Accordingly, it is important

to be able to properly survey and monitor for Kr-85, and to assess the skin dose to workers who could be exposed to Kr-85 in the event of an accident with decayed spent fuel.Licensees

may wish to reevaluate

whether Emergency

Action Levels specified

in the emergency

plan and procedures

governing

decayed fuel-handling, activities

appropriately

focus on concern for onsite workers and Kr-85 releases in areas'where decayed spent fuel accidents

could occur, for example, the'spent

fuel pool working floor. Furthermore, licensees

may wish to determine

if emergency plans and corresponding

implementing

procedures

address the means for limiting radiological

exposures

of onsite personnel

who are in other areas of the plant.Among other things, moving onsite personnel

away from the plume and shutting off building air intakes downwind from the source may be appropriate.

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. Ross Di ctor Division'of

Operational

Events Assessment

Office of Nuclear Reactor Regulation

Technical

Contacts:

Charles S. Hinson, NRR (301) 492-3142 Robert A. Meck, RES (301) 492-3737 Attachments:

1. Figure 1, Dose Consequences

of a Spent Fuel Drop Accident 2. List of Recently Issued NRC Information

Notices

N N..Atitchment

1 IN 90-08 I February 1, 1990 DOSE CONSEQUENCES

OF A SPENT FUEL DROP ACCIDENT-103 102 ArMR SHUTDOWN Figure 1 Attachment

2 in 90-08 February 1, 1990 Page I of I LIST OF RECENTLT ISSUED NRC INFORMATION

NOTICES}stanntina

V

• _Notice No.BJ-23, Supp. 2..I m ..-90-O7*90-06 90-05 -90-04 90-03 90-02 90-01_- --- 89-90 -_89-89 Subject Potential

for Gas Binding.of Ngh-Prussura

Ssfety InJection

Pumps During a Loss-of-Coolant

Accident New information

Rgarding Insulation

Materal1 Performance

and Debris Blockage of PWR Contain.ment Sumps Potential

for Loss of Shutdown Cooling While at Low Reactor Coolant Levels Inter-Systes

Discharge

of Reactor Coolant Cracking of the Upper Shell-to-TransitIon

Cone 6irth Welds in Steam Generators

Malfunction

of Borg-Warner

Bolted Sonnet Check Valves Caused by Failure of the Swing Arm Potential

Degradation

of Secondary

Containsent

Importance

of Proper Response to Self-Identifled

Violations

by Licensees Pressurizr-Safty

l Lift Setpoint Shift.Eient Notificatin

Workshests

Date or Issuance 1/31/90 1/30/90 Issued to All holders of OLs or CPs for PWRs.All holders of OLts or CPs for nuclear power reactors.1/29/90 All holders of OLs or CPs for nuclear power reactors.1/29/90 1/26/90 1/23/90 All holders of OLs or CPs for nuclear power reactors.All holders'of

OLs or CPs for Westinghouse- designed and Coatustion

Engineering-designed

nuclear power reactors.All holders of OLs or CPs for nuclear power reactors.1/22/90 All holders of OLs.or CPa for BWRs.1/12/90 All holders of NRC materials

licenses.12t/28/81 All olbders or OLs or CPs for Prs.12/26/839 All holders of OLs or CPs for nuclear power reactors:'

OL

• Operating

License CP

• Construction

Permit UNITED STATES NUCLEAR REGULATORY

COMMISSION

WASHINGTON, D.C. 20555'!OFFICIAL BUSINESS PENALTY FOR PRIVATE USE. UOO IPOSTAGE It FEES PAIDI jusNAcj

-11 --1 IN 90-08 February 1, 1990 Discussion:

Kr-85 emits beta radiation

with a maximum energy of 0.67 MeY for 99.6 percent of the decays and 0.51 MeY gamma radiation

for 0.4 percent of the decays. Conse-quently, direct exposure to this gas would result in a dose to the skin approxi-nately 100 times the whole-body

dose. Analysis of the relative consequences (in terms of radiological

doses) of a cask-drop

accident as a function of decay time of the fuel is illustrated

in Figure 1. In the event of a serious accident involving

decayed spent fuel, protective

actions would be needed for personnel on site, while offsite doses (assuming

an exclusion

area radius of 1 mile from the plant site) would be well below the Environmental

Protection

Agency's Protective

Action Guides. Accordingly, it is important

to be able to properly survey and monitor for Kr-85, and to assess the skin dose to workers who could be exposed to Kr-85 in the event of an accident with decayed spent fuel.Licensees

may wish to reevaluate

whether Emergency

Action Levels specified

in the emergency

plan and procedures

governing

decayed fuel-handling

activities

appropriately

focus on concern for onsite workers and Kr-85 releases in areas where decayed spent fuel accidents

could occur, for example, the spent fuel pool working floor. Furthermore, licensees

may wish to determine

if emergency plans and corresponding

implementing

procedures

address the means for limiting radiological

exposures

of onsite personnel

who are in other areas of the plant.Among other things, moving onsite personnel

away from the plume and shutting off building air intakes downwind from the source may be appropriate.

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:

Charles S. Hinson, NRR (301) 492-3142 Robert A. Meck, RES (301) 492-3737 Attachments:

1. Figure 1, Dose Consequences

of a Spent Fuel Drop Accident 2. List of Recently Issued NRC Information

Notices*See Previous Concurrence

RPB:DREP SC:RPB:DREP

SC:RPB:DREP

DREP D:DREP RPB:ARM C/OG :DOEA:NR CSHinson*

JEWigginton*

LJCunningham*

LCohen* FJCongel*

TechEd* CHBerlinger*

01/11/90 01/11/90 01/17/90 01/17/90 01/24/90 01/25/90 01/25/90 D 9/DOCUMENT NAME: INFORMATION

NOTICE MECK

ef r, .-I IN 90-XX January xx, 1990 DISTRIBUTION:

FJCongel I .9 LJCunningham, NRR THEssig, NRR JEWigginton, NRR RAErickson, NRR RJBarrett, NRR RLAnderson, TTC CSHinson, NRR LKCohen, NRR CHBerlinger, NRR CERossi, NRR Central Files RPB R/F*See Previous Concurrence

RPB:DREP CSHInson*01/11/90 SC:RPB:DREP

JEWigginton*

01/11/90 SC:RPB:DREP

LJCunnlnghal*

01/17/90 DREP LCohen*01/17/90 D:DREP FJCongel*01/24/90 RPB:ARM TechEd*01/25/90 C/d@CB:DOEA:NRR

CHBerlinger

O1/jVi90 D/DOEA:NRR

CERossi 01/ /90 DOCUMENT NAME: INFORMATION

NOTICE MECK

• *}. 'IN 90-XX January xx, 1990 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 Regional Administrator

of the appropriate

regional office.Charles E. Rossi, Director Division of Operational

Events Assessment

Office of Nuclear Reactor Regulation

Technical

Contacts: Charles S. Hinson, NRR (301) 492-3142 Robert A. Heck, RES (301) 492-3737 Attachments:

1.2.Figure 1 List of Recently Issued NRC Information

Notices RPB:DREP SC lPJgBREP CSHinsoIMJ

pginton 01/ll /so ° /90 D/DOEA:NRR

CERossi 01/ /90 4 Cu Ingham LCohen 01/7/90 1/%A 190 D:DRE 2 PB:Mf FJConge T ol1zq/90 01&5/90 onr C/OGCB:DOEA:NRR

CHBerlinger

01/ /90