Information Notice 1990-08, KR-85 Hazards from Decayed Fuel: Difference between revisions

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{{#Wiki_filter:UNITED STATES NUCLEAR REGULATORY
{{#Wiki_filter:UNITED STATES


COMMISSION
NUCLEAR REGULATORY COMMISSION


===OFFICE OF NUCLEAR REACTOR REGULATION===
OFFICE OF NUCLEAR REACTOR REGULATION
WASHINGTON, D.C. 20555 February 1. 1990 NRC INFORMATION


NOTICE NO. 90-08: KR-85 HAZARDS FROM DECAYED FUEL
WASHINGTON, D.C. 20555 February 1. 1990
NRC INFORMATION NOTICE NO. 90-08:   KR-85 HAZARDS FROM DECAYED FUEL


==Addressees==
==Addressees==
:
:
All holders of operating
All holders of operating licenses or construction permits for nuclear power


licenses or construction
reactors and holders of licenses for permanently shutdown facilities with


permits for nuclear power reactors and holders of licenses for permanently
fuel on site.
 
shutdown facilities
 
with fuel on site.


==Purpose==
==Purpose==
: This information
:
This information notice alerts addressees to potential problems resulting from


notice alerts addressees
*the .accidental release of Kr-85 from decayed fuel. It isexpected that reci


to potential
pients will review the Information for applicability to their facilities and


problems resulting
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.


from*the .accidental
Desripionof Circumstances:      ,-
  During the licensing reviews for the Oconee independent spent fuel storage


release of Kr-85 from decayed fuel. It is expected that reci pients will review the Information
Installation,, and inthe decommissioning of the La Crosse and Dresden Unit 1 power reactors, the NRC staff analyzed the radiological hazards associated


for applicability
.with the gases In decayed spent fuel. The age of the nuclear power industry


to their facilities
and the lack of a permanent repository for spent fuel have resulted in the


and consider actions, as appropriate, to avoid similar problems.
accumulation of decayed'spent fuel.* Decayed spent fuel ismanipulated after


However, sugges-tions co'ntained
long shutdowns of operating reactors, during spent fuel pool re-racking, during


in this information
mo~vement to alternate reactor sites or independent spent fuel storage instal- lations, and during decommissioning. Analysis of hypothetical accidents


notice do not constitute
involving decayed spent fuel has focused attention on potential difficulties


NRC 'requirements;
that'could be associated with the exposure of onsi1te personnel to an accidental
therefore, no specific action or written response is required.Desripionof


Circumstances:
release of Kr-85. IKr-85 isa noble gas fission product that is present inthe
During the licensing


reviews for the Oconee independent
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


spent fuel storage Installation,, and in the decommissioning
gaseous fission products (1-129 being the exception, but in low abundance),,
  Kr-85 becomes Increasingly the dominant nuclide inthe accident source term


of the La Crosse and Dresden Unit 1 power reactors, the NRC staff analyzed the radiological
for gap releases as decay times increase. After 2 weeks of decay, Kr-85 is


hazards associated.with the gases In decayed spent fuel. The age of the nuclear power industry and the lack of a permanent
a significant nuclide inthe source term, and after 190 days of decay, it is


repository
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


for spent fuel have resulted in the accumulation
of a gap release from decayed fuel.


of decayed'spent
9001260198  40--


fuel.* Decayed spent fuel is manipulated
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


after long shutdowns
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


of operating
terms of radiological doses) of a cask-drop accident as a function of decay time


reactors, during spent fuel pool re-racking, during mo~vement
of the fuel is illustrated in Figure 1. In the event of a serious accident


to alternate
involving decayed spent fuel, protective actions would be needed for personnel


reactor sites or independent
on site, while offsite doses (assuming an exclusion area radius of 1 mile from


spent fuel storage instal-lations, and during decommissioning.
the plant site) would be well below the Environmental Protection Agency's


Analysis of hypothetical
Protective Action Guides. Accordingly, it is important to be able to properly


accidents involving
survey and monitor for Kr-85, and to assess the skin dose to workers who could


decayed spent fuel has focused attention
be exposed to Kr-85 in the event of an accident with decayed spent fuel.


on potential
Licensees may wish to reevaluate whether Emergency Action Levels specified in


difficulties
the emergency plan and procedures governing decayed fuel-handling, activities


that'could
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


be associated
pool working floor. Furthermore, licensees may wish to determine if emergency


with the exposure of onsi1te personnel
plans and corresponding implementing procedures address the means for limiting


to an accidental
radiological exposures of onsite personnel who are in other areas of the plant.


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.
Among other things, moving onsite personnel away from the plume and shutting


It has a 10.76-year
off building air intakes downwind from the source may be appropriate.


half-life, and, as a result of the considerably
This information notice requires no specific action or written response. If you


shorter half-lveso
have any questions about the information in this notice, please contact one of


ital l te gaseous fission products (1-129 being the exception, but in low abundance),, Kr-85 becomes Increasingly
the technical contacts listed below or the appropriate NRR project manager.


the dominant nuclide in the accident source term for gap releases as decay times increase.
Charles E. Ross Di ctor


After 2 weeks of decay, Kr-85 is a significant
Division'of Operational Events Assessment


nuclide in the source term, and after 190 days of decay, it is the predominant
Office of Nuclear Reactor Regulation


gaseous nuclide for a gap release. The unusual decay character- istics of K~r-85 give cause for focusing attention
Technical Contacts:  Charles S. Hinson, NRR


on the onsite consequences
(301) 492-3142 Robert A. Meck, RES


of a gap release from decayed fuel.,-9001260198
(301) 492-3737 Attachments:
40--
1. Figure 1, Dose Consequences of a
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.
Spent Fuel Drop Accident


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
2. List of Recently Issued NRC Information Notices


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


doses) of a cask-drop
. Atitchment 1 IN 90-08      I


accident as a function of decay time of the fuel is illustrated
February 1, 1990 DOSE CONSEQUENCES OF


in Figure 1. In the event of a serious accident involving
A SPENT FUEL DROP ACCIDENT-
      103
      102 ArMR SHUTDOWN


decayed spent fuel, protective
Figure 1


actions would be needed for personnel on site, while offsite doses (assuming
V        _*
                                                                                          Attachment 2 in90-08 February 1, 1990
                                                                                          Page I of I


an exclusion
LIST OF RECENTLT ISSUED


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


Protection
}stanntina


Agency's Protective
Date or


Action Guides. Accordingly, it is important
Notice No.     Subject                        Issuance    Issued to


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
BJ-23,         Potential for Gas Binding      1/31/90
                                Supp. 2                                                  All holders of OLs


may wish to reevaluate
.of Ngh-Prussura Ssfety                    or CPs for PWRs.


whether Emergency
InJection Pumps During a


Action Levels specified
Loss-of-Coolant Accident


in the emergency
. . I      m . .    -
                              90-O7*          New information Rgarding        1/30/90    All holders of OLts


plan and procedures
Insulation Materal1                        or CPs for nuclear


governing
Performance and Debris                    power reactors.


decayed fuel-handling, activities
Blockage of PWR Contain.


appropriately
ment Sumps


focus on concern for onsite workers and Kr-85 releases in areas'where decayed spent fuel accidents
90-06          Potential for Loss of          1/29/90    All holders of OLs


could occur, for example, the'spent
Shutdown Cooling While                    or CPs for nuclear


fuel pool working floor. Furthermore, licensees
atLow Reactor Coolant                      power reactors.


may wish to determine
Levels


if emergency plans and corresponding
90-05      -  Inter-Systes Discharge of      1/29/90    All holders of OLs


implementing
Reactor Coolant                            or CPs for nuclear


procedures
power reactors.


address the means for limiting radiological
90-04          Cracking of the Upper Shell-    1/26/90    All holders'of OLs


exposures
to-TransitIon Cone 6irth                  or CPs for Westinghouse- Welds in Steam Generators                  designed and Coatustion


of onsite personnel
Engineering-designed
 
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
nuclear power reactors.


notice requires no specific action or written response.
90-03          Malfunction of Borg-Warner      1/23/90    All holders of OLs


If you have any questions
Bolted Sonnet Check Valves                  or CPs for nuclear


about the information
Caused by Failure of the                   power reactors.


in this notice, please contact one of the technical
Swing Arm


contacts listed below or the appropriate
90-02          Potential Degradation of        1/22/90
                                            Secondary Containsent                      All holders of OLs.


NRR project manager.Charles E. Ross Di ctor Division'of
or CPa for BWRs.


Operational
90-01          Importance of Proper            1/12/90    All holders of NRC


===Events Assessment===
Response to Self-Identifled                materials licenses.
Office of Nuclear Reactor Regulation


Technical
Violations by Licensees


Contacts:
_- ---  89-90    -_    Pressurizr-Safty l
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
Lift Setpoint Shift.           12t/28/81  All olbders or OLs


Notices
or CPs for Prs.


N N..Atitchment
89-89          Eient Notificatin              12/26/839  All holders of OLs


1 IN 90-08 I February 1, 1990 DOSE CONSEQUENCES
Workshests                                or CPs for nuclear


OF A SPENT FUEL DROP ACCIDENT-103 102 ArMR SHUTDOWN Figure 1 Attachment
power reactors:'
                            OL


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


NOTICES}stanntina
CP


V
* Construction Permit


* _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
UNITED STATES


for Gas Binding.of Ngh-Prussura
===NUCLEAR REGULATORY COMMISSION===
    WASHINGTON, D.C. 20555'!''                                                                                  IPOSTAGE ItFEES


Ssfety InJection
jusNAcj


Pumps During a Loss-of-Coolant
PAIDI


Accident New information
OFFICIAL BUSINESS


Rgarding Insulation
PENALTY FOR PRIVATE USE. UOO


Materal1 Performance
- 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


and Debris Blockage of PWR Contain.ment Sumps Potential
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


for Loss of Shutdown Cooling While at Low Reactor Coolant Levels Inter-Systes
terms of radiological doses) of a cask-drop accident as a function of decay time


Discharge
of the fuel is illustrated in Figure 1. In the event of a serious accident


of Reactor Coolant Cracking of the Upper Shell-to-TransitIon
involving decayed spent fuel, protective actions would be needed for personnel


===Cone 6irth Welds in Steam Generators===
on site, while offsite doses (assuming an exclusion area radius of 1 mile from
Malfunction


of Borg-Warner
the plant site) would be well below the Environmental Protection Agency's


Bolted Sonnet Check Valves Caused by Failure of the Swing Arm Potential
Protective Action Guides. Accordingly, it is important to be able to properly


Degradation
survey and monitor for Kr-85, and to assess the skin dose to workers who could


of Secondary
be exposed to Kr-85 in the event of an accident with decayed spent fuel.


Containsent
Licensees may wish to reevaluate whether Emergency Action Levels specified in


Importance
the emergency plan and procedures governing decayed fuel-handling activities


of Proper Response to Self-Identifled
appropriately focus on concern for onsite workers and Kr-85 releases in areas


Violations
where decayed spent fuel accidents could occur, for example, the spent fuel


by Licensees Pressurizr-Safty
pool working floor. Furthermore, licensees may wish to determine if emergency


l Lift Setpoint Shift.Eient Notificatin
plans and corresponding implementing procedures address the means for limiting


Workshests
radiological exposures of onsite personnel who are in other areas of the plant.


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
Among other things, moving onsite personnel away from the plume and shutting


OLs or CPs for Westinghouse- designed and Coatustion
off building air intakes downwind from the source may be appropriate.


Engineering-designed
This information notice requires no specific action or written response. If you


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
have any questions about the information in this notice, please contact one of


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:'
the technical contacts listed below or the appropriate NRR project manager.
OL


* Operating
Charles E. Rossi, Director


License CP
Division of Operational Events Assessment


* Construction
Office of Nuclear Reactor Regulation
 
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
Technical Contacts:      Charles S. Hinson, NRR


accident as a function of decay time of the fuel is illustrated
(301) 492-3142 Robert A. Meck, RES


in Figure 1. In the event of a serious accident involving
(301) 492-3737 Attachments:
  1. Figure 1, Dose Consequences of a


decayed spent fuel, protective
Spent Fuel Drop Accident


actions would be needed for personnel on site, while offsite doses (assuming
2. List of Recently Issued NRC Information Notices


an exclusion
*See Previous Concurrence


area radius of 1 mile from the plant site) would be well below the Environmental
RPB:DREP SC:RPB:DREP SC:RPB:DREP        DREP      D:DREP    RPB:ARM    C/OG :DOEA:NR


Protection
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


Agency's Protective
9/
  DOCUMENT NAME:    INFORMATION NOTICE MECK


Action Guides. Accordingly, it is important
ef r,      .


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
-   I


may wish to reevaluate
IN 90-XX


whether Emergency
January xx, 1990 DISTRIBUTION:
        FJCongelI . 9 LJCunningham, NRR


Action Levels specified
THEssig, NRR


in the emergency
JEWigginton, NRR


plan and procedures
RAErickson, NRR


governing
RJBarrett, NRR


decayed fuel-handling
RLAnderson, TTC


activities
CSHinson, NRR


appropriately
LKCohen, NRR


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


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


may wish to determine
Central Files


if emergency plans and corresponding
RPB R/F


implementing
*See Previous Concurrence


procedures
RPB:DREP SC:RPB:DREP SC:RPB:DREP      DREP    D:DREP  RPB:ARM  C/d@CB:DOEA:NRR


address the means for limiting radiological
CSHInson* JEWigginton* LJCunnlnghal*  LCohen* FJCongel* TechEd*  CHBerlinger


exposures
01/11/90 01/11/90      01/17/90      01/17/90 01/24/90 01/25/90  O1/jVi90
        D/DOEA:NRR


of onsite personnel
CERossi


who are in other areas of the plant.Among other things, moving onsite personnel
01/ /90
        DOCUMENT NAME:  INFORMATION NOTICE MECK


away from the plume and shutting off building air intakes downwind from the source may be appropriate.
* *}.   '
                                                                  IN 90-XX


This information
January xx, 1990 No specific action or written response is required by this information notice.


notice requires no specific action or written response.
If you have any questions about this matter, please contact one of the technical


If you have any questions
contacts listed below or the Regional Administrator of the appropriate regional


about the information
office.


in this notice, please contact one of the technical
Charles E. Rossi, Director


contacts listed below or the appropriate
Division of Operational Events Assessment


NRR project manager.Charles E. Rossi, Director Division of Operational
===Events Assessment===
Office of Nuclear Reactor Regulation
Office of Nuclear Reactor Regulation


Technical
Technical Contacts:  Charles S. Hinson, NRR


Contacts:
(301) 492-3142 Robert A. Heck, RES
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
(301) 492-3737 Attachments:        1.  Figure 1
                          2.   List of Recently Issued NRC Information Notices


Notices*See Previous Concurrence
RPB:DREP SC lPJgBREP


RPB:DREP SC:RPB:DREP
CSHinsoIMJ pginton


SC:RPB:DREP
01/ll /so  °  /90
                              401/7/90
                                Cu Ingham


DREP D:DREP RPB:ARM C/OG :DOEA:NR CSHinson*
D:DRE 2 LCohen FJConge
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
1/%A 190 ol1zq/90
                                                              PB:Mf


ef r, .-I IN 90-XX January xx, 1990 DISTRIBUTION:
T
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
01&5/90
 
                                                                      C/OGCB:DOEA:NRR
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
CHBerlinger


O1/jVi90 D/DOEA:NRR
01/ /90
 
                                                        onr
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
D/DOEA:NRR


===Events Assessment===
CERossi
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}}
01/ /90}}


{{Information notice-Nav}}
{{Information notice-Nav}}

Latest revision as of 04:02, 24 November 2019

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
Office of Nuclear Reactor Regulation
To:
References
IN-90-008, NUDOCS 9001260198
Download: ML031130307 (7)
v • d • e


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 isexpected 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 inthe 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 ismanipulated 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 isa noble gas fission product that is present inthe

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 inthe accident source term

for gap releases as decay times increase. After 2 weeks of decay, Kr-85 is

a significant nuclide inthe 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

V _*

Attachment 2 in90-08 February 1, 1990

Page I of I

LIST OF RECENTLT ISSUED

NRCINFORMATION NOTICES

}stanntina

Date or

Notice No. Subject Issuance Issued to

BJ-23, Potential for Gas Binding 1/31/90

Supp. 2 All holders of OLs

.of Ngh-Prussura Ssfety or CPs for PWRs.

InJection Pumps During a

Loss-of-Coolant Accident

. . I m . . -

90-O7* New information Rgarding 1/30/90 All holders of OLts

Insulation Materal1 or CPs for nuclear

Performance and Debris power reactors.

Blockage of PWR Contain.

ment Sumps

90-06 Potential for Loss of 1/29/90 All holders of OLs

Shutdown Cooling While or CPs for nuclear

atLow Reactor Coolant power reactors.

Levels

90-05 - Inter-Systes Discharge of 1/29/90 All holders of OLs

Reactor Coolant or CPs for nuclear

power reactors.

90-04 Cracking of the Upper Shell- 1/26/90 All holders'of OLs

to-TransitIon Cone 6irth or CPs for Westinghouse- Welds in Steam Generators designed and Coatustion

Engineering-designed

nuclear power reactors.

90-03 Malfunction of Borg-Warner 1/23/90 All holders of OLs

Bolted Sonnet Check Valves or CPs for nuclear

Caused by Failure of the power reactors.

Swing Arm

90-02 Potential Degradation of 1/22/90

Secondary Containsent All holders of OLs.

or CPa for BWRs.

90-01 Importance of Proper 1/12/90 All holders of NRC

Response to Self-Identifled materials licenses.

Violations by Licensees

_- --- 89-90 -_ Pressurizr-Safty l

Lift Setpoint Shift. 12t/28/81 All olbders or OLs

or CPs for Prs.

89-89 Eient Notificatin 12/26/839 All holders of OLs

Workshests or CPs for nuclear

power reactors:'

OL

  • Operating License

CP

  • Construction Permit

UNITED STATES

NUCLEAR REGULATORY COMMISSION

WASHINGTON, D.C. 20555'! IPOSTAGE ItFEES

jusNAcj

PAIDI

OFFICIAL BUSINESS

PENALTY FOR PRIVATE USE. UOO

- 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:

FJCongelI . 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 SC:RPB:DREP SC:RPB:DREP DREP D:DREP RPB:ARM C/d@CB:DOEA:NRR

CSHInson* JEWigginton* LJCunnlnghal* LCohen* FJCongel* TechEd* CHBerlinger

01/11/90 01/11/90 01/17/90 01/17/90 01/24/90 01/25/90 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. Figure 1

2. List of Recently Issued NRC Information Notices

RPB:DREP SC lPJgBREP

CSHinsoIMJ pginton

01/ll /so ° /90

401/7/90

Cu Ingham

D:DRE 2 LCohen FJConge

1/%A 190 ol1zq/90

PB:Mf

T

01&5/90

C/OGCB:DOEA:NRR

CHBerlinger

01/ /90

onr

D/DOEA:NRR

CERossi

01/ /90


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