Information Notice 1996-39, Estimates of Decay Heat Using ANS 5.1 Decay Heat Standard May Vary Significantly: Difference between revisions

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{{#Wiki_filter:KY/UNITED STATESNUCLEAR REGULATORY COMMISSIONOFFICE OF NUCLEAR REACTOR REGULATIONWASHINGTON, D.C. 20555-0001July 5, 1996NRC INFORMATION NOTICE 96-39: ESTIMATES OF DECAY HEAT USING ANS 5.1 DECAYHEAT STANDARD MAY VARY SIGNIFICANTLY
{{#Wiki_filter:KY/UNITED STATES NUCLEAR REGULATORY
 
COMMISSION
 
===OFFICE OF NUCLEAR REACTOR REGULATION===
WASHINGTON, D.C. 20555-0001 July 5, 1996 NRC INFORMATION
 
NOTICE 96-39: ESTIMATES
 
OF DECAY HEAT USING ANS 5.1 DECAY HEAT STANDARD MAY VARY SIGNIFICANTLY


==Addressees==
==Addressees==
All holders of operating licenses or construction permits for nuclear powerreactors.
All holders of operating
 
licenses or construction
 
permits for nuclear power reactors.


==Purpose==
==Purpose==
The U.S. Nuclear Regulatory Commission (NRC) is issuing this informationnotice to alert addressees to the sensitivity of analytical results to inputparameters used with American Nuclear Society standard 5.1 on decay heat(Reference). It is expected that recipients will review the information forapplicability to their facilities and consider actions, as appropriate, toavoid similar problems. However, suggestions contained in this informationnotice are not NRC requirements; therefore, no specific action or writtenresponse is required.BackgroundAmerican Nuclear Society standard 5.1 (ANS 5.1 standard) for decay heatgeneration in nuclear power plants provides a simplified means of estimatingnuclear fuel cooling requirements that can be readily programmed into computercodes used to predict plant performance. The ANS 5.1 standard models theenergy release from the fission products of U-235, U-238, and Pu-239 using asummation of exponential terms with empirical constants. Corrections areprovided to account for energy release from the decay of U-239 and Np-239, andfor the neutron activation of stable fission products. Although the empiricalconstants are built into the standard, certain data inputs are left to thediscretion of the user. These options permit accounting for differences inpower history, initial fuel enrichment, and neutron flux level.
The U.S. Nuclear Regulatory
 
Commission (NRC) is issuing this information
 
notice to alert addressees
 
to the sensitivity
 
of analytical
 
results to input parameters
 
used with American Nuclear Society standard 5.1 on decay heat (Reference).
 
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
 
American Nuclear Society standard 5.1 (ANS 5.1 standard)  
for decay heat generation
 
in nuclear power plants provides a simplified
 
means of estimating
 
nuclear fuel cooling requirements
 
that can be readily programmed
 
into computer codes used to predict plant performance.
 
The ANS 5.1 standard models the energy release from the fission products of U-235, U-238, and Pu-239 using a summation
 
of exponential
 
terms with empirical
 
constants.
 
Corrections
 
are provided to account for energy release from the decay of U-239 and Np-239, and for the neutron activation
 
of stable fission products.
 
Although the empirical constants
 
are built into the standard, certain data inputs are left to the discretion
 
of the user. These options permit accounting
 
for differences
 
in power history, initial fuel enrichment, and neutron flux level.Description
 
of Circumstances
 
During a review of decay heat estimates
 
calculated
 
using various codes for the same plant, the staff found that the predicted
 
decay heat varied considerably.
 
This was unexpected
 
because the analyses were made using the 1979 ANS 5.1 standard and were to be used in best-estimate" thermal-hydraulic
 
analyses.The staff compared calculations
 
of decay heat using MELCOR, TRAC, RELAP, and a vendor code for a pressurized
 
water reactor operating
 
at 1933 megawatts thermal (MWT). The staff made 3 calculations
 
using RELAP but varied certain inputs. These calculations
 
appear as RELAP,, RELAP 2 , and RELAP in the following
 
tables. The decay heat estimates
 
in MWT calculated
 
?or 2 hours PD& IC ';cs 95-o3q 9(.oqoS 9606250199
1 O A 0o 161b ussOAf '~'k
 
IN 96-39 July 5, 1996 after shutdown of the reactor using the various codes and allowable
 
inputs were as follows: MELCOR -20.70 MWT Vendor code -22.15 MWT RELAP 1 -22.02 MWT RELAP 2 -26.13 MWT RELAP 3 -20.82 MWT TRAC -22.02 MWT ORIGEN -20.90 MWT It should be noted that the differences
 
in predicted
 
decay heat resulted from the parameters
 
selected for input and not from the codes themselves.
 
The last entry in the table was not calculated
 
by the ANS 5.1 standard but was calculated
 
by the ORIGEN computer code. ORIGEN does not use empirical
 
methods to calculate
 
decay heat but tracks the buildup and decay of the individual
 
fission products within the reactor core during operation
 
and shutdown.ORIGEN also includes the effect of element transmutation
 
from neutron capture, both in fissile isotopes and fission products.
 
Because ORIGEN is a rigorous calculation
 
of all decay heat inputs, it was used in the calculations
 
for decay heat in attached Figure 1 and is contrasted
 
with attached Figure 2 using decay heat internally
 
calculated
 
by RELAP to the ANS 5.1 standard.Discussion
 
The staff found that the different
 
decay heat estimates
 
occurred because the ANS 5.1 standard was not fully utilized in the selection
 
of inputs. Attached Table 1 shows the various inputs to the codes to estimate decay heat.Attached Table 2 shows the effect of different
 
assumptions
 
on best estimate calculations
 
of decay heat 2 hours after shutdown of the reactor.The variation
 
in peak cladding temperatures
 
with various predictions
 
of decay heat may be seen by comparing
 
the attached Figures 1 and 2. These figures are plots of the peak cladding temperatures
 
for a hypothetical
 
beyond-design-basis
 
loss-of-feedwater
 
event. For Figure 1, values of decay heat predicted
 
by the ORIGEN code were input directly into RELAP. Figure 2 is the same event with the decay heat internally
 
calculated
 
by RELAP using the ANS 5.1 standard.Input assumptions
 
to the standard were those that produced the highest values of decay heat denoted in Table 1 as RELAP 2.The difference
 
in predicted
 
peak core cladding temperatures (approximately
 
250° K [6300 F]) demonstrates
 
the importance
 
of carefully
 
selecting
 
required input parameters
 
when using ANS 5.1 because analytical
 
results may be significantly
 
affected.
 
Depending
 
on the input parameters
 
selected the results may be conservative
 
or nonconservative.
 
IN 96-39 July 5, 1996 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
 
Office of Nuclear Reactor Regulation (NRR) project manager.Brian K. Grimes, Acting Director Division of Reactor Program Management
 
===Office of Nuclear Reactor Regulation===
Technical
 
contacts: W. L. Jensen, NRR (301) 415-2856 Internet:wljenrc.gov
 
J. L. Birmingham, NRR (301) 415-2829 Internet:jlb4@nrc.gov
 
Attachments:
1. Table 1, 'Decay Heat Options Using ANS 5.1, 1979" 2. Table 2, "Relative
 
Importance
 
of Options 7200 Seconds (2 hours) After Reactor Shutdown" 3. Figure 1, "Peak Core' Cladding Temperature
 
Calculated
 
by ORIGEN" and Figure 2, "Peak Core Cladding Temperature
 
Calculated
 
by ANS 5.1" 4. List of Recently Issued NRC Information
 
Notices Reference: "American
 
National Standard for Decay Heat Power in Light Water American Nuclear Society Standards
 
Committee
 
Working Group, ANS August 29, 1979.Reactors," 5.1, Approved 44A0eiIII
 
Attachment
 
1 IN 96-39 July 5, 1996 Table 1. Decay Heat Options Using ANS 5.1, 1979 l I l l Power l Fissile Codes Actinides
 
R-Factor G-Factor Si History Elements Vendor Yes 0.6 Not ANS 1.347 3 Yrs. 3 RELAP 1  No NA MAX NA Infinite All_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _U 2 3 5 RELAP 2  Yes 1.0 MAX NA Infinite All_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ ___ ___U 2 3 5 RELAP 3  No NA No NA Infinite All_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _U 2 3 5 MELCOR Yes 0.526 Yes 0.713 1.6 Yrs. 3 TRAC No NA Yes 1.0 Infinite All_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ __I_ U 2 3 5 Notes: Actinides:
Neutron adding to the total capture by U238 produces U239 which decays into Np239 which also decays, decay heat. Not all the above code inputs included actinide decay.R-factor:
The actinide production
 
multiplier.
 
The standard states that the value of R shall be supplied and justified
 
by the user.G-factor:
A decay heat multiplier
 
to account for the effect of neutron capture in fission products.
 
The standard provides the option of using a maximum value table for the G-factor or a best estimate equation for the first 10,000 seconds.Si: Fissions per initial fissile atom. Si is a multiplier
 
applied to the G-factor equation.Power History: Length of full-power
 
operation
 
before shutdown.Fissile Elements:
The standard permits decay power to be fractionally
 
attributed
 
to the fission products of 3 fissile isotopes U235, U238, and Pu239. The vendor input attributed
 
the fractional
 
fission product power as 0.487 from U235, 0.069 from U238, and 0.443 from U239. The fractional
 
fission product power input to MELCOR was 0.647 from U235, 0.0425 from U238, and 0.31 from Pu239. The other code inputs assumed all fission product power came from U235.
 
Attachment
 
2* IN 96-39 July 5, 1996 Table 2. Relative Importance
 
of Options 7200 Seconds (2 hours) After Reactor Shutdown Complete Set For: Options as InDut and Varied Decay Heat in MWT MELCOR MELCOR assumptions (see Table 1) 20.70______________________________________________________________________________
Increase R from .526 to .6 21.03 Increase Si from .713 to 1.347 21.13 Operation
 
time from 1.6 years to 3 years 21.40 Vendor fissile isotopes 21.12 Vendor heavy element equation 21.86 Vendor code Vendor G-factor equation 22.15-__ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ -_ _ _ _ _ _ _ _ _ _ _ _ANS 5.1 G-factor and heavy element eqs. 21.12 No actinides
 
18.65 Gmax rather than equation 19.44 Infinite operation
 
20.53 RELAP 1  All fission from U235 22.02 ----------------
RELAP 2  Add actinides
 
with R=1 26.13 RELAP 3  Remove actinides
 
and G-factor 20.82 TRAC Include G-factor equation with Si-i 22.02 Note: This table illustrates
 
the relative importance
 
of the various options contained
 
in the 1979 ANS 5.1 standard.
 
Starting with the decay heat rate calculated
 
by MELCOR using the inputs listed in Table 1, the options were changed in sequence to those used in the vendor computer code. The options were then changed to those used in the RELAP 1 analyses, the RELAP 2 analyses, the RELAP 3 analyses, and the TRAC analyses.
 
.i Figure 1 Peak Core Cladding Temperature
 
1400.0 1200.0 2'CD E 0 1000.0 800.0 Attachment
 
3 IN 96-39 July 5, 1996- 12000.0 600.0 L 400.0 -0.0 4000.0 8000.0 Time (s)1400.0 Figure 2 Peak Core Cladding Temperature
 
Ug 1L&... A& IC C 4 var.qy ntIvat 04 1200.0 1-Infinite Operati All U235 Fissic G=Gmax Actinides
 
with I£'0 a E 02 1000.0 800.0 ,n..ulLwu
 
U)Y MIND ;.. I on in 1 R=1/600.0 400.0 L 0.C.........I D 4000.0 8000.0 12000.0 Time (s)
Attachment
 
4 IN 96-39 July 5, 1996 LIST OF RECENTLY ISSUED NRC INFORMATION
 
NOTICES Information
 
Date of Notice No. Subject Issuance Issued to 96-38 96-37 96-36 96-35 96-34 Results of Steam Generator Tube Examinations
 
Inaccurate
 
Reactor Water Level Indication
 
and Inad-vertent Draindown
 
During Shutdown Degradation
 
of Cooling Water Systems Due to Icing Failure of Safety Systems on Self-Shielded
 
Irradia-tors Because of Inadequate
 
Maintenance
 
and Training Hydrogen Gas Ignition during Closure Welding of a VSC-24 Multi-Assembly
 
Sealed Basket Erroneous
 
Data From Defective
 
===Thermocouple===
Results in a Fire Implementation
 
of 10 CFR 50.55a(g)
(6) (ii)(A),"Augmented
 
Examination
 
of Reactor Vessel" Cross-Tied
 
Safety Injec-tion Accumulators
 
Inaccuracy
 
of Diagnostic
 
Equipment
 
for Motor-Operated Butterfly
 
Valves Requirements
 
in 10 CFR Part 21 for Reporting
 
and Evaluating
 
Software Errors 06/21/96 06/18/96 06/12/96 06/11/96 05/31/96 05/24/96 06/05/96 05/22/96 05/21/96 05/20/96 All holders of OLs or CPs for pressurized
 
water reactors All pressurized
 
water reactor facilities
 
holding an operating
 
license or a construction
 
permit All holders of OLs or CPs for nuclear power reactors All U.S. Nuclear Regulatory
 
Commission
 
irradiator
 
licensees
 
and vendors All holders of OLs or CPs for nuclear power reactors All material and fuel cycle licensees
 
that monitor tem-perature with thermocouples
 
All holders of OLs or CPs for nuclear power reactors All holders of OLs or CPs for pressurized
 
water reactors All holders of OLs or CPs for nuclear power reactors All holders of OLs or CPs for nuclear power reactors 96-33 96-32 96-31 96-30 96-29 OL = Operating
 
License CP -Construction
 
Permit
 
IN 96-39 July 5, 1996 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
 
Office of Nuclear Reactor Regulation (NRR) project manager.OrfIoaw Stgned by Brin K. Grimes Brian K. Grimes, Acting Director Division of Reactor Program Management
 
===Office of Nuclear Reactor Regulation===
Technical
 
contacts: W. L. Jensen, NRR (301) 415-2856 Internet:wl
 
jnrc.gov J. L. Birmingham, NRR (301) 415-2829 Internet:jlb4@nrc.gov
 
Attachments:
1. Table 1, 'Decay Heat Options Using ANS 5.1, 1979" 2. Table 2, 'Relative
 
Importance
 
of Options 7200 Seconds (2 hours) After Reactor Shutdown" 3. Figure 1, "Peak Core Cladding Temperature
 
Calculated
 
by ORIGEN" and Figure 2, "Peak Core Cladding Temperature
 
Calculated
 
by ANS 5.1" 4. List of Recently Issued NRC Information
 
Notices Reference: "American
 
National Standard for Decay Heat Power in Light Water American Nuclear Society Standards
 
Committee
 
Working Group, ANS August 29, 1979.Reactors," 5.1, Approved*See previous concurrence
 
Tech Editor reviewed and concurred
 
on 03/19/96 DOCUMENT NAME: 96-39. IN To eceiw a copy of this document, hdMcata In the box: 'C' -Copy wlo attechmentenclosure
 
E' -Copy w/attachment/.nclosure
 
W -No copy"""7  OFFICE TECH CONTS I C:PECB:DRPM
 
I I 1II NAME WLJensen*
AEChaffee*
m lJLBirmingham*
C ,v_, DATE 04/02/96 05/16/96 07/1 /96 1 1 03/19/96 1 [ 1 1 __
IN 96-xx July xx, 1996 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
 
Office of Nuclear Reactor Regulation (NRR) project manager.Brian K. Grimes, Acting Director Division of Reactor Program Management
 
===Office of Nuclear Reactor Regulation===
Technical
 
contacts: W. L. Jensen, NRR (301) 415-2856 Internet:wlj~nrc.gov
 
J. L. Birmingham, NRR (301) 415-2829 Internet:jlb4enrc.gov
 
Attachments:
1. Table 1, "Decay Heat Options Using ANS 5.1, 1979" 2. Table 2, "Relative
 
Importance
 
of Options 7200 Seconds (2 hours) After Reactor Shutdown" 3. Figure 1, "Peak Core Cladding Temperature
 
Calculated
 
by ORIGEN" and Figure 2, "Peak Core Cladding Temperature
 
Calculated
 
by ANS 5.1" 5. List of Recently Issued NRC Information
 
Notices Reference: "American
 
National Standard for Decay Heat Power in Light Water Reactors," American Nuclear Society Standards
 
Committee
 
Working Group ANS 5.1, Approved August 29, 1979.*See previous concurrence
 
OFFICE SASG:DSSA:NRR
 
SASG:DSSA:NRR
 
l D/DSSA:NRR
 
NAME l WLJensen*
RCaruso* l GMHolahan*
DATE 04/02/96 04/04/96 04/30/96 OFFICE TECHED:RPB
 
1 PECB:DRPM:NRR
 
_ C/PECB:DRPM:NRR
 
AD/DRPM:NRR
 
NAME B. Calure* JBirmingham*
AEChaffee*
BKGrimes DATE 03/19/96 103/19/96
1 05/16/96 1 / /96 OFFICIAL DOCUMENT NAME: G:\JLB\DKAY4.IN
 
m,4A
 
IN 96-xx June xx, 1996 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
 
Office of Nuclear Reactor Regulation (NRR) project manager.Brian K. Grimes, Acting Director Division of Reactor Program Management
 
===Office of Nuclear Reactor Regulation===
Technical
 
contacts: W. L. Jensen, NRR (301) 415-2856 Internet:wljenrc.gov
 
J. L. Birmingham, NRR (301) 415-2829 Internet:jlb4@nrc.gov
 
Attachments:
1. Table 1, Decay Heat Options Using ANS 5.1, 1979." 2. Table 2, Relative Importance
 
of Options 7200 Seconds (2 hours) After Reactor Shutdown'3. Figure 1, "Peak Core Cladding Temperature
 
Calculated
 
by ORIGEN." 4. Figure 2, 'Peak Core Cladding Temperature
 
Calculated
 
by ANS 5.1.'5. List of Recently Issued NRC Information
 
Notices Reference:
American National Standard for Decay Heat Power in Light Water Reactors," American Nuclear Society Standards
 
Committee
 
Working Group ANS 5.1, Approved August 29, 1979.*Sep nrpvious concurrence
 
OFFICE SASG:DSSA:NRR
 
SASG:DSSA:NRR
 
D/DSSA:NRR
 
NAME WLJensen*
RCaruso* GMHolahan*
nATF 0a4/02/96 04/04/96 04/30/96_.-OFFICE TECHED:RPB
 
PECB:DRPM:NRR
 
C/PECB:DRPM:NRR
 
AD/DRPM:NRR
 
NAME B. Calure* JBirmingham*
AEChaffeeX
 
BKGrimes DATE 03/19/96 .03/19/96 .05//b/96 1 05/ /96)FFICIAL DOCUMENT NAME: G:\JLb\UKAY4.IN
 
mtEA,
K-,-IN 96-xx May xx, 1996 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
 
Office of Nuclear Reactor Regulation (NRR) project manager.Brian K. Grimes, Acting Director Division of Reactor Program Management
 
===Office of Nuclear Reactor Regulation===
Technical
 
contacts: W. L. Jensen, NRR (301) 415-2856 Internet:wl
 
jnrc.gov J. L. Birmingham, NRR (301) 415-2829 Internet:jlb4@nrc.gov
 
Attachments:
1. Table 1, "Decay Heat Options Using ANS 5.1, 1979." 2. Table 2, "Relative
 
Importance
 
of Options 7200 Seconds (2 hours) After Reactor Shutdown'3. Figure 1, *Peak Core Cladding Temperature
 
Calculated
 
by ORIGEN." 4. Figure 2, "Peak Core Cladding Temperature
 
Calculated
 
by ANS 5.1." 5. List of Recently Issued NRC Information
 
Notices Reference:
'American
 
National Standard for Decay Heat Power in Light Water Reactors," American Nuclear Society Standards
 
Committee
 
Working Group ANS 5.1, Approved August 29, 1979.*Sge ntrvinut concurrence
 
OFFICE SASG:DSSA:NRR
 
SASG:DSSA:NRR
 
D/DSSA:NRR
 
NAME WLJensen*
RCaruso* GMHolahan*
DATE 4T\1o 04/02/96 04/04/96 04/30/96 OFFICE TECHED:RPB
 
1 PECB:DRPM:NRR
 
CAE A AD/DRPM:NRR
 
NAME B B. Calure* JBirmingham*
AE a fel BKGrimes DATE l 03/19/96 03/19/96 0 5/14/96 ; 05/ /96-rr .. ---r ... --.~. -t -.gA I JFIHUAL WLUMNI KAM: U: \-JLt1\UA1Uq.
 
IN AV0en&
K>-IN 96-xx May xx, 1996 This information
 
notice requires no specific action or written response.
 
If you have any questions
 
about the information
 
in this notice, please conta t one of the technical
 
contacts listed below or the appropriate
 
Office of Nuclear Reactor Regulation (NRR) project manager.Brian K. Grimes, Acting Dire or Division of Reactor Progra Management
 
Office of Nuclear Reacto egulation Technical
 
contacts:
W. L. Jensen, NRR (301) 415-2856 Internet:wlj@nrc.gov
 
J. L. Birmingham, NRR (301) 415-2829 Internet:jlb4@nrc.gov
 
Attachments:
1. Table 1, "Decay Heat Options Using ANS 5 , 1979." 2. Table 2, 'Relative
 
Importance
 
of Option 7200 Seconds (2 hours) Aft Reactor Shutdown." 3. Figure 1, "Peak Core Cladding Temper ure Calculated
 
by ORIGEN." 4. Figure 2, 'Peak Core Cladding Tegmp ature Calculated
 
by ANS 5.1.'5. List of Recently Issued NRC 19o( ation Notices Reference:
'American
 
National Standard fg ecay Heat Power in Light Water Reactors," American Nuclear Society Sta d ds Committee
 
Working Group ANS 5.1, Approved August 29, 1979.*See previous concu e OFFICE SASG:DA:NRR
 
SASG:DSSA:NRR
 
D/DSSA:NRR
 
NAME WLJfaen* I RCaruso* GMHolahan*
DATE I 04 2/96 1 04/04/96 I 04/30/96.1. .. .*OFFICE f ECHED:RPB
 
PECB:DRPM:NRR
 
C/PECB:DRPM:NRR
 
AD/DRPM:NRR
 
NAME- / B. Calure* JBirmingham*
AEChaffee
 
BKGrimes DATE / 03/19/96 03/19/96 05/ /96 05/ /96 bew Tl Ir-luzT l u .s .. -1 -1 %vV UFFIGJAL UDUMEIN NAME: W \)Lb \UKAY4. 11 &W
 
IN 96-xx May xx, 1996 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
 
Office of Nuclear Reactor Regulation (NRR) project manager.Brian K. Grimes, Acting Director Division of Reactor Program Management
 
===Office of Nuclear Reactor Regulation===
Technical
 
contacts: W. L. Jensen, NRR (301) 415-2856 Internet:wlj@nrc.gov
 
J. L. Birmingham, NRR (301) 415-2829 Internet:jlb4@nrc.gov
 
Attachments:
1. Table 1, "Decay Heat Options Using ANS 5.1, 1979." 2. Table 2, wRelative
 
Importance
 
of Options 7200 Seconds (2 hours) After Reactor Shutdown.'
3. Figure 1, wPeak Core Cladding Temperature
 
Calculated
 
by ORIGEN.3 4. Figure 2, uPeak Core Cladding Temperature
 
Calculated
 
by ANS 5.1." 5. List of Recently Issued NRC Information
 
Notices Reference: "American
 
National Standard for Decay Heat Power in Light Water Reactors," American Nuclear Society Standards
 
Committee
 
Working Group ANS 5.1, Approved August 29, 1979.A*See Drevious concurrence
 
OFFICE SASG:DSSA:NRR
 
SASG:DSSA:NRR
 
D1XaS.a NAME W W ensen RCaruso k M -ahan DATE 04/02/96 04/04/96 i4/ 0/96 OFFICE TECHED:RPB
 
PECB:DRPM:NRR
 
C/PECB:DRPM:NRR
 
D/DRPM:NRR
 
NAME B. Calure* JBirmingham*
AEChaffee
 
===DLCrutchfield===
DATE 1 03/19/96 03/19/96 1 04/ /96 j 04/ /96 UN ILIAL UL r *:- W..DtuF in WFICIAL UUCUMMN NAM: U: XJLt$UKU>Y4.
 
IrN
 
IN 96-xx April xx, 1996 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
 
Office of Nuclear Reactor Regulation (NRR) project manager.Denni .Crutchfield, Director Division f Reactor Program Management
 
===Office of lear Reactor Regulation===
Technical
 
contacts:
W. L. Jensen, NRR (301) 415-2856 Internet:wlj~nrc.gov
 
J. L. Birmingham, NRR (301) 415-2829 Internet:jlb4@nrc.gov
 
Attachments:
1. Table 1, Decay Heat Options Using ANS 5.1, 1979.0 2. Table 2, "Relative
 
Importance
 
of Options 7200 Seconds (2 hours) After Reactor Shutdown." 3. Figure 1, NPeak Core Cladding Temperature
 
Calculated
 
by ORIGEN." 4. Figure 2, "Peak Core Cladding Temperature
 
Calculated
 
by ANS 5.1." 5. List of Recently Issued NRC Information
 
Notices Reference:
American National Standard for Decay Heat Power in Light Water Reactors," American Nuclear Society Standards
 
Committee
 
Working Group ANS 5.1, Approved August 29, 1979.*See previous concurrence
 
OFFICE SASG:DSSA!RR
 
SASQ: PSSA:NRR D/DSSA:NRR
 
NAME jW Jenkeg( RCaJ & GMHolahan DATE I 04/2 /96 I 04/10/96 I 04/ /96 OFFICE TECHED:RPB
 
PECB:DhPM:NRR
 
C/PECB:DRPM:NRR
 
D/DRPM:NRR
 
NAME B. Calure* JBirmingham*
AEChaffee
 
===DLCrutchfield===
DATE 03/19/96 03/19/96 04/ /96 04/ /96 FFICIAL DOCUMENT NAME: G:\JLB\UKAY4.IN
 
5. List of RecentlySosued
 
NRC Information
 
Notices Reference:
1. "American
 
National Standard for Decay Heat Power in Light Water Reactors," American Nuclear Society Standards


==Description of Circumstances==
Committee
During a review of decay heat estimates calculated using various codes for thesame plant, the staff found that the predicted decay heat varied considerably.This was unexpected because the analyses were made using the 1979 ANS 5.1standard and were to be used in best-estimate" thermal-hydraulic analyses.The staff compared calculations of decay heat using MELCOR, TRAC, RELAP, anda vendor code for a pressurized water reactor operating at 1933 megawattsthermal (MWT). The staff made 3 calculations using RELAP but varied certaininputs. These calculations appear as RELAP,, RELAP2, and RELAP in thefollowing tables. The decay heat estimates in MWT calculated ?or 2 hoursPD& IC ';cs 95-o3q 9(.oqoS9606250199 1 O A0o 161b ussOAf '~'k


IN 96-39July 5, 1996 after shutdown of the reactor using the various codes and allowable inputswere as follows:MELCOR -20.70 MWTVendor code -22.15 MWTRELAP1 -22.02 MWTRELAP2 -26.13 MWTRELAP3 -20.82 MWTTRAC -22.02 MWTORIGEN -20.90 MWTIt should be noted that the differences in predicted decay heat resulted fromthe parameters selected for input and not from the codes themselves.The last entry in the table was not calculated by the ANS 5.1 standard but wascalculated by the ORIGEN computer code. ORIGEN does not use empirical methodsto calculate decay heat but tracks the buildup and decay of the individualfission products within the reactor core during operation and shutdown.ORIGEN also includes the effect of element transmutation from neutron capture,both in fissile isotopes and fission products. Because ORIGEN is a rigorouscalculation of all decay heat inputs, it was used in the calculations fordecay heat in attached Figure 1 and is contrasted with attached Figure 2 usingdecay heat internally calculated by RELAP to the ANS 5.1 standard.DiscussionThe staff found that the different decay heat estimates occurred because theANS 5.1 standard was not fully utilized in the selection of inputs. AttachedTable 1 shows the various inputs to the codes to estimate decay heat.Attached Table 2 shows the effect of different assumptions on best estimatecalculations of decay heat 2 hours after shutdown of the reactor.The variation in peak cladding temperatures with various predictions of decayheat may be seen by comparing the attached Figures 1 and 2. These figures areplots of the peak cladding temperatures for a hypothetical beyond-design-basisloss-of-feedwater event. For Figure 1, values of decay heat predicted by theORIGEN code were input directly into RELAP. Figure 2 is the same event withthe decay heat internally calculated by RELAP using the ANS 5.1 standard.Input assumptions to the standard were those that produced the highest valuesof decay heat denoted in Table 1 as RELAP2.The difference in predicted peakcore cladding temperatures (approximately 250° K [6300 F]) demonstrates theimportance of carefully selecting required input parameters when using ANS 5.1because analytical results may be significantly affected. Depending on theinput parameters selected the results may be conservative or nonconservative.
Working Group ANS 5.1. Approved August 29. 1979.OFFICE SASG:DSSA:NRR


IN 96-39July 5, 1996 This information notice requires no specific action or written response. Ifyou have any questions about the information in this notice, please contactone of the technical contacts listed below or the appropriate Office ofNuclear Reactor Regulation (NRR) project manager.Brian K. Grimes, Acting DirectorDivision of Reactor Program ManagementOffice of Nuclear Reactor RegulationTechnical contacts:W. L. Jensen, NRR(301) 415-2856Internet:wljenrc.govJ. L. Birmingham, NRR(301) 415-2829Internet:jlb4@nrc.govAttachments:1. Table 1, 'Decay Heat Options Using ANS 5.1, 1979"2. Table 2, "Relative Importance of Options 7200 Seconds(2 hours) After Reactor Shutdown"3. Figure 1, "Peak Core' Cladding Temperature Calculated by ORIGEN" andFigure 2, "Peak Core Cladding Temperature Calculated by ANS 5.1"4. List of Recently Issued NRC Information NoticesReference:"American National Standard for Decay Heat Power in Light WaterAmerican Nuclear Society Standards Committee Working Group, ANSAugust 29, 1979.Reactors,"5.1, Approved44A0eiIII
SASG:DSSA:NRR


Attachment 1IN 96-39July 5, 1996 Table 1. Decay Heat Options Using ANS 5.1, 1979l I l l Power l FissileCodes Actinides R-Factor G-Factor Si History ElementsVendor Yes 0.6 Not ANS 1.347 3 Yrs. 3RELAP1  No NA MAX NA Infinite All_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _U 2 3 5RELAP2  Yes 1.0 MAX NA Infinite All_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ ___ ___U 2 3 5RELAP3  No NA No NA Infinite All_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _U 2 3 5MELCOR Yes 0.526 Yes 0.713 1.6 Yrs. 3TRAC No NA Yes 1.0 Infinite All_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ __I_ U 2 3 5Notes:Actinides: Neutronadding to the totalcapture by U238 produces U239 which decays into Np239 which also decays,decay heat. Not all the above code inputs included actinide decay.R-factor: The actinide production multiplier. The standard states that the value of R shallbe supplied and justified by the user.G-factor: A decay heat multiplier to account for the effect of neutron capture in fissionproducts. The standard provides the option of using a maximum value table for the G-factor ora best estimate equation for the first 10,000 seconds.Si: Fissions per initial fissile atom. Si is a multiplier applied to the G-factor equation.Power History: Length of full-power operation before shutdown.Fissile Elements: The standard permits decay power to be fractionally attributed to thefission products of 3 fissile isotopes U235, U238, and Pu239. The vendor input attributed thefractional fission product power as 0.487 from U235, 0.069 from U238, and 0.443 from U239. Thefractional fission product power input to MELCOR was 0.647 from U235, 0.0425 from U238, and0.31 from Pu239. The other code inputs assumed all fission product power came from U235.
D/DSSA:NRR


Attachment 2* IN 96-39July 5, 1996 Table 2. Relative Importance of Options7200 Seconds (2 hours) After Reactor ShutdownComplete Set For: Options as InDut and Varied Decay Heat in MWTMELCOR MELCOR assumptions (see Table 1) 20.70______________________________________________________________________________Increase R from .526 to .6 21.03Increase Si from .713 to 1.347 21.13Operation time from 1.6 years to 3 years 21.40Vendor fissile isotopes 21.12Vendor heavy element equation 21.86Vendor code Vendor G-factor equation 22.15-__ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ -_ _ _ _ _ _ _ _ _ _ _ _ANS 5.1 G-factor and heavy element eqs. 21.12No actinides 18.65Gmax rather than equation 19.44Infinite operation 20.53RELAP1  All fission from U235 22.02 ----------------RELAP2  Add actinides with R=1 26.13RELAP3  Remove actinides and G-factor 20.82TRAC Include G-factor equation with Si-i 22.02Note: This table illustrates the relative importance of the various options contained in the1979 ANS 5.1 standard. Starting with the decay heat rate calculated by MELCOR using the inputslisted in Table 1, the options were changed in sequence to those used in the vendor computercode. The options were then changed to those used in the RELAP1 analyses, the RELAP2 analyses,the RELAP3analyses, and the TRAC analyses.
NAME WLJensen RCaruso GMHolahan DATE 03/ /96 03/ /96 03/ /96 03/ /96 OFFICE TECHED:RPB


.iFigure 1 Peak Core Cladding Temperature1400.01200.02'CDE01000.0800.0Attachment 3IN 96-39July 5, 1996- 2000.0600.0 L400.0 -0.04000.0 8000.0Time (s)1400.0Figure 2 Peak Core Cladding TemperatureUg 1L&... A& IC C 4var.qy ntIvat 041200.0 1-Infinite OperatiAll U235 FissicG=GmaxActinides with I£'0aE021000.0800.0,n..ulLwu U)Y MIND ;.. Ionin 1R=1/600.0400.0 L0.C.........ID4000.08000.012000.0Time (s)
PECB:DRPM:NRR
Attachment 4IN 96-39July 5, 1996 LIST OF RECENTLY ISSUEDNRC INFORMATION NOTICESInformation Date ofNotice No. Subject Issuance Issued to96-3896-3796-3696-3596-34Results of Steam GeneratorTube ExaminationsInaccurate Reactor WaterLevel Indication and Inad-vertent Draindown DuringShutdownDegradation of CoolingWater Systems Due to IcingFailure of Safety Systemson Self-Shielded Irradia-tors Because of InadequateMaintenance and TrainingHydrogen Gas Ignitionduring Closure Weldingof a VSC-24 Multi-AssemblySealed BasketErroneous Data FromDefective ThermocoupleResults in a FireImplementation of 10 CFR50.55a(g) (6) (ii)(A),"Augmented Examinationof Reactor Vessel"Cross-Tied Safety Injec-tion AccumulatorsInaccuracy of DiagnosticEquipment for Motor-Operated Butterfly ValvesRequirements in 10 CFRPart 21 for Reporting andEvaluating Software Errors06/21/9606/18/9606/12/9606/11/9605/31/9605/24/9606/05/9605/22/9605/21/9605/20/96All holders of OLs or CPsfor pressurized waterreactorsAll pressurized waterreactor facilities holdingan operating license or aconstruction permitAll holders of OLs or CPsfor nuclear power reactorsAll U.S. Nuclear RegulatoryCommission irradiatorlicensees and vendorsAll holders of OLs or CPsfor nuclear power reactorsAll material and fuel cyclelicensees that monitor tem-perature with thermocouplesAll holders of OLs or CPsfor nuclear power reactorsAll holders of OLs or CPsfor pressurized waterreactorsAll holders of OLs or CPsfor nuclear power reactorsAll holders of OLs or CPsfor nuclear power reactors96-3396-3296-3196-3096-29OL = Operating LicenseCP -Construction Permit


IN 96-39July 5, 1996 This information notice requires no specific action or written response. Ifyou have any questions about the information in this notice, please contactone of the technical contacts listed below or the appropriate Office ofNuclear Reactor Regulation (NRR) project manager.OrfIoaw Stgned by Brin K. GrimesBrian K. Grimes, Acting DirectorDivision of Reactor Program ManagementOffice of Nuclear Reactor RegulationTechnical contacts:W. L. Jensen, NRR(301) 415-2856Internet:wl jnrc.govJ. L. Birmingham, NRR(301) 415-2829Internet:jlb4@nrc.govAttachments:1. Table 1, 'Decay Heat Options Using ANS 5.1, 1979"2. Table 2, 'Relative Importance of Options 7200 Seconds(2 hours) After Reactor Shutdown"3. Figure 1, "Peak Core Cladding Temperature Calculated by ORIGEN" andFigure 2, "Peak Core Cladding Temperature Calculated by ANS 5.1"4. List of Recently Issued NRC Information NoticesReference:"American National Standard for Decay Heat Power in Light WaterAmerican Nuclear Society Standards Committee Working Group, ANSAugust 29, 1979.Reactors,"5.1, Approved*See previous concurrenceTech Editor reviewed and concurred on 03/19/96DOCUMENT NAME:96-39. INTo eceiw a copy of this document, hdMcata In the box: 'C' -Copy wloattechmentenclosure E' -Copy w/attachment/.nclosure W -No copy"""7 OFFICE TECH CONTS I C:PECB:DRPM I I 1IINAME WLJensen* AEChaffee* mlJLBirmingham* C ,v_,DATE 04/02/96 05/16/96 07/1 /961 1 03/19/96 1 [ 1 1 __
C/PECB:DRPM:NRR
IN 96-xxJuly xx, 1996 This information notice requires no specific action or written response. Ifyou have any questions about the information in this notice, please contactone of the technical contacts listed below or the appropriate Office ofNuclear Reactor Regulation (NRR) project manager.Brian K. Grimes, Acting DirectorDivision of Reactor Program ManagementOffice of Nuclear Reactor RegulationTechnical contacts:W. L. Jensen, NRR(301) 415-2856Internet:wlj~nrc.govJ. L. Birmingham, NRR(301) 415-2829Internet:jlb4enrc.govAttachments:1. Table 1, "Decay Heat Options Using ANS 5.1, 1979"2. Table 2, "Relative Importance of Options 7200 Seconds(2 hours) After Reactor Shutdown"3. Figure 1, "Peak Core Cladding Temperature Calculated by ORIGEN" andFigure 2, "Peak Core Cladding Temperature Calculated by ANS 5.1"5. List of Recently Issued NRC Information NoticesReference:"American National Standard for Decay Heat Power in Light Water Reactors,"American Nuclear Society Standards Committee Working Group ANS 5.1, ApprovedAugust 29, 1979.*See previous concurrenceOFFICE SASG:DSSA:NRR SASG:DSSA:NRR l D/DSSA:NRRNAME l WLJensen* RCaruso* l GMHolahan*DATE04/02/9604/04/9604/30/96OFFICE TECHED:RPB 1 PECB:DRPM:NRR _ C/PECB:DRPM:NRR AD/DRPM:NRRNAME B. Calure* JBirmingham* AEChaffee* BKGrimesDATE 03/19/96 103/19/96 1 05/16/96 1 / /96OFFICIAL DOCUMENT NAME:G:\JLB\DKAY4.INm,4A


IN 96-xxJune xx, 1996 This information notice requires no specific action or written response. Ifyou have any questions about the information in this notice, please contactone of the technical contacts listed below or the appropriate Office ofNuclear Reactor Regulation (NRR) project manager.Brian K. Grimes, Acting DirectorDivision of Reactor Program ManagementOffice of Nuclear Reactor RegulationTechnical contacts:W. L. Jensen, NRR(301) 415-2856Internet:wljenrc.govJ. L. Birmingham, NRR(301) 415-2829Internet:jlb4@nrc.govAttachments:1. Table 1, Decay Heat Options Using ANS 5.1, 1979."2. Table 2, Relative Importance of Options 7200 Seconds(2 hours) After Reactor Shutdown'3. Figure 1, "Peak Core Cladding Temperature Calculated by ORIGEN."4. Figure 2, 'Peak Core Cladding Temperature Calculated by ANS 5.1.'5. List of Recently Issued NRC Information NoticesReference:American National Standard for Decay Heat Power in Light Water Reactors,"American Nuclear Society Standards Committee Working Group ANS 5.1, ApprovedAugust 29, 1979.*Sep nrpvious concurrenceOFFICE SASG:DSSA:NRR SASG:DSSA:NRR D/DSSA:NRRNAME WLJensen* RCaruso* GMHolahan*nATF0a4/02/9604/04/9604/30/96_.-OFFICE TECHED:RPB PECB:DRPM:NRR C/PECB:DRPM:NRR AD/DRPM:NRRNAME B. Calure* JBirmingham* AEChaffeeX BKGrimesDATE 03/19/96 .03/19/96 .05//b/96 1 05/ /96)FFICIAL DOCUMENT NAME:G:\JLb\UKAY4.INmtEA,
D/DRPM:NRR
K-,-IN 96-xxMay xx, 1996 This information notice requires no specific action or written response. Ifyou have any questions about the information in this notice, please contactone of the technical contacts listed below or the appropriate Office ofNuclear Reactor Regulation (NRR) project manager.Brian K. Grimes, Acting DirectorDivision of Reactor Program ManagementOffice of Nuclear Reactor RegulationTechnical contacts:W. L. Jensen, NRR(301) 415-2856Internet:wl jnrc.govJ. L. Birmingham, NRR(301) 415-2829Internet:jlb4@nrc.govAttachments:1. Table 1, "Decay Heat Options Using ANS 5.1, 1979."2. Table 2, "Relative Importance of Options7200 Seconds (2 hours) After Reactor Shutdown'3. Figure 1, *Peak Core Cladding Temperature Calculated by ORIGEN."4. Figure 2, "Peak Core Cladding Temperature Calculated by ANS 5.1."5. List of Recently Issued NRC Information NoticesReference:'American National Standard for Decay Heat Power in Light Water Reactors,"American Nuclear Society Standards Committee Working Group ANS 5.1, ApprovedAugust 29, 1979.*Sge ntrvinut concurrenceOFFICE SASG:DSSA:NRR SASG:DSSA:NRR D/DSSA:NRRNAME WLJensen* RCaruso* GMHolahan*DATE4T\1o04/02/9604/04/9604/30/96OFFICE TECHED:RPB 1 PECB:DRPM:NRR CAE A AD/DRPM:NRRNAME B B. Calure* JBirmingham* AE a fel BKGrimesDATE l 03/19/96 03/19/96 05/14/96 ; 05/ /96-rr .. ---r ... --.~. -t -.gA IJFIHUAL WLUMNI KAM:U: \-JLt1\UA1Uq. INAV0en&
K>-IN 96-xxMay xx, 1996 This information notice requires no specific action or written response. Ifyou have any questions about the information in this notice, please conta tone of the technical contacts listed below or the appropriate Office ofNuclear Reactor Regulation (NRR) project manager.Brian K. Grimes, Acting Dire orDivision of Reactor Progra ManagementOffice of Nuclear Reacto egulationTechnical contacts: W. L. Jensen, NRR(301) 415-2856Internet:wlj@nrc.govJ. L. Birmingham, NRR(301) 415-2829Internet:jlb4@nrc.govAttachments:1. Table 1, "Decay Heat Options Using ANS 5 , 1979."2. Table 2, 'Relative Importance of Option7200 Seconds (2 hours) Aft Reactor Shutdown."3. Figure 1, "Peak Core Cladding Temper ure Calculated by ORIGEN."4. Figure 2, 'Peak Core Cladding Tegmp ature Calculated by ANS 5.1.'5. List of Recently Issued NRC 19o( ation NoticesReference:'American National Standard fg ecay Heat Power in Light Water Reactors,"American Nuclear Society Sta d ds Committee Working Group ANS 5.1, ApprovedAugust 29, 1979.*See previous concu eOFFICE SASG:DA:NRR SASG:DSSA:NRR D/DSSA:NRRNAME WLJfaen* I RCaruso* GMHolahan*DATE I 04 2/96 1 04/04/96 I 04/30/96.1. .. .*OFFICE f ECHED:RPB PECB:DRPM:NRR C/PECB:DRPM:NRR AD/DRPM:NRRNAME- / B. Calure* JBirmingham* AEChaffee BKGrimesDATE / 03/19/96 03/19/96 05/ /96 05/ /96bew Tl Ir-luzT l u .s .. -1 -1 %vVUFFIGJAL UDUMEIN NAME:W \)Lb \UKAY4. 11 &W


IN 96-xxMay xx, 1996 This information notice requires no specific action or written response. Ifyou have any questions about the information in this notice, please contactone of the technical contacts listed below or the appropriate Office ofNuclear Reactor Regulation (NRR) project manager.Brian K. Grimes, Acting DirectorDivision of Reactor Program ManagementOffice of Nuclear Reactor RegulationTechnical contacts:W. L. Jensen, NRR(301) 415-2856Internet:wlj@nrc.govJ. L. Birmingham, NRR(301) 415-2829Internet:jlb4@nrc.govAttachments:1. Table 1, "Decay Heat Options Using ANS 5.1, 1979."2. Table 2, wRelative Importance of Options 7200 Seconds (2 hours) AfterReactor Shutdown.'3. Figure 1, wPeak Core Cladding Temperature Calculated by ORIGEN.34. Figure 2, uPeak Core Cladding Temperature Calculated by ANS 5.1."5. List of Recently Issued NRC Information NoticesReference:"American National Standard for Decay Heat Power in Light Water Reactors,"American Nuclear Society Standards Committee Working Group ANS 5.1, ApprovedAugust 29, 1979.A*See Drevious concurrenceOFFICE SASG:DSSA:NRR SASG:DSSA:NRR D1XaS.aNAME W W ensen RCaruso k M -ahanDATE04/02/9604/04/96i4/ 0/96OFFICE TECHED:RPB PECB:DRPM:NRR C/PECB:DRPM:NRR D/DRPM:NRRNAME B. Calure* JBirmingham* AEChaffee DLCrutchfieldDATE 1 03/19/96 03/19/96 1 04/ /96 j 04/ /96UN ILIAL UL r *:- W..DtuF inWFICIAL UUCUMMN NAM:U: XJLt$UKU>Y4. IrN
NAME JBirmingham


IN 96-xxApril xx, 1996 This information notice requires no specific action or written response. Ifyou have any questions about the information in this notice, please contactone of the technical contacts listed below or the appropriate Office ofNuclear Reactor Regulation (NRR) project manager.Denni .Crutchfield, DirectorDivision f Reactor Program ManagementOffice of lear Reactor RegulationTechnical contacts: W. L. Jensen, NRR(301) 415-2856Internet:wlj~nrc.govJ. L. Birmingham, NRR(301) 415-2829Internet:jlb4@nrc.govAttachments:1. Table 1, Decay Heat Options Using ANS 5.1, 1979.02. Table 2, "Relative Importance of Options 7200 Seconds (2 hours) AfterReactor Shutdown."3. Figure 1, NPeak Core Cladding Temperature Calculated by ORIGEN."4. Figure 2, "Peak Core Cladding Temperature Calculated by ANS 5.1."5. List of Recently Issued NRC Information NoticesReference:American National Standard for Decay Heat Power in Light Water Reactors,"American Nuclear Society Standards Committee Working Group ANS 5.1, ApprovedAugust 29, 1979.*See previous concurrenceOFFICE SASG:DSSA!RR SASQ: PSSA:NRR D/DSSA:NRRNAME jW Jenkeg( RCaJ & GMHolahanDATE I 04/2 /96 I 04/10/96 I 04/ /96OFFICE TECHED:RPB PECB:DhPM:NRR C/PECB:DRPM:NRR D/DRPM:NRRNAME B. Calure* JBirmingham* AEChaffee DLCrutchfieldDATE 03/19/96 03/19/96 04/ /96 04/ /96FFICIAL DOCUMENT NAME:G:\JLB\UKAY4.IN
AEChaffee


5. List of RecentlySosued NRC Information NoticesReference:1. "American National Standard for Decay Heat Power in Light WaterReactors," American Nuclear Society Standards Committee Working GroupANS 5.1. Approved August 29. 1979.OFFICE SASG:DSSA:NRR SASG:DSSA:NRR D/DSSA:NRRNAME WLJensen RCaruso GMHolahanDATE 03/ /96 03/ /96 03/ /96 03/ /96OFFICE TECHED:RPB PECB:DRPM:NRR C/PECB:DRPM:NRR D/DRPM:NRRNAME JBirmingham AEChaffee DLCrutchfieldDATE 03//7/96 03/ /96 03/ /96 03/ /96OFFICIAL DOCUMENT NAME: G:\JLB\DECAY HT.JLB
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DATE 03//7/96 03/ /96 03/ /96 03/ /96 OFFICIAL DOCUMENT NAME: G:\JLB\DECAY


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Revision as of 14:07, 31 August 2018

Estimates of Decay Heat Using ANS 5.1 Decay Heat Standard May Vary Significantly
ML031060021
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: 07/05/1996
From: Grimes B K
Office of Nuclear Reactor Regulation
To:
References
IN-96-039, NUDOCS 9606250199
Download: ML031060021 (15)
v • d • e


KY/UNITED STATES NUCLEAR REGULATORY

COMMISSION

OFFICE OF NUCLEAR REACTOR REGULATION

WASHINGTON, D.C. 20555-0001 July 5, 1996 NRC INFORMATION

NOTICE 96-39: ESTIMATES

OF DECAY HEAT USING ANS 5.1 DECAY HEAT STANDARD MAY VARY SIGNIFICANTLY

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 alert addressees

to the sensitivity

of analytical

results to input parameters

used with American Nuclear Society standard 5.1 on decay heat (Reference).

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

American Nuclear Society standard 5.1 (ANS 5.1 standard)

for decay heat generation

in nuclear power plants provides a simplified

means of estimating

nuclear fuel cooling requirements

that can be readily programmed

into computer codes used to predict plant performance.

The ANS 5.1 standard models the energy release from the fission products of U-235, U-238, and Pu-239 using a summation

of exponential

terms with empirical

constants.

Corrections

are provided to account for energy release from the decay of U-239 and Np-239, and for the neutron activation

of stable fission products.

Although the empirical constants

are built into the standard, certain data inputs are left to the discretion

of the user. These options permit accounting

for differences

in power history, initial fuel enrichment, and neutron flux level.Description

of Circumstances

During a review of decay heat estimates

calculated

using various codes for the same plant, the staff found that the predicted

decay heat varied considerably.

This was unexpected

because the analyses were made using the 1979 ANS 5.1 standard and were to be used in best-estimate" thermal-hydraulic

analyses.The staff compared calculations

of decay heat using MELCOR, TRAC, RELAP, and a vendor code for a pressurized

water reactor operating

at 1933 megawatts thermal (MWT). The staff made 3 calculations

using RELAP but varied certain inputs. These calculations

appear as RELAP,, RELAP 2 , and RELAP in the following

tables. The decay heat estimates

in MWT calculated

?or 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> PD& IC ';cs 95-o3q 9(.oqoS 9606250199

1 O A 0o 161b ussOAf '~'k

IN 96-39 July 5, 1996 after shutdown of the reactor using the various codes and allowable

inputs were as follows: MELCOR -20.70 MWT Vendor code -22.15 MWT RELAP 1 -22.02 MWT RELAP 2 -26.13 MWT RELAP 3 -20.82 MWT TRAC -22.02 MWT ORIGEN -20.90 MWT It should be noted that the differences

in predicted

decay heat resulted from the parameters

selected for input and not from the codes themselves.

The last entry in the table was not calculated

by the ANS 5.1 standard but was calculated

by the ORIGEN computer code. ORIGEN does not use empirical

methods to calculate

decay heat but tracks the buildup and decay of the individual

fission products within the reactor core during operation

and shutdown.ORIGEN also includes the effect of element transmutation

from neutron capture, both in fissile isotopes and fission products.

Because ORIGEN is a rigorous calculation

of all decay heat inputs, it was used in the calculations

for decay heat in attached Figure 1 and is contrasted

with attached Figure 2 using decay heat internally

calculated

by RELAP to the ANS 5.1 standard.Discussion

The staff found that the different

decay heat estimates

occurred because the ANS 5.1 standard was not fully utilized in the selection

of inputs. Attached Table 1 shows the various inputs to the codes to estimate decay heat.Attached Table 2 shows the effect of different

assumptions

on best estimate calculations

of decay heat 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> after shutdown of the reactor.The variation

in peak cladding temperatures

with various predictions

of decay heat may be seen by comparing

the attached Figures 1 and 2. These figures are plots of the peak cladding temperatures

for a hypothetical

beyond-design-basis

loss-of-feedwater

event. For Figure 1, values of decay heat predicted

by the ORIGEN code were input directly into RELAP. Figure 2 is the same event with the decay heat internally

calculated

by RELAP using the ANS 5.1 standard.Input assumptions

to the standard were those that produced the highest values of decay heat denoted in Table 1 as RELAP 2.The difference

in predicted

peak core cladding temperatures (approximately

250° K [6300 F]) demonstrates

the importance

of carefully

selecting

required input parameters

when using ANS 5.1 because analytical

results may be significantly

affected.

Depending

on the input parameters

selected the results may be conservative

or nonconservative.

IN 96-39 July 5, 1996 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

Office of Nuclear Reactor Regulation (NRR) project manager.Brian K. Grimes, Acting Director Division of Reactor Program Management

Office of Nuclear Reactor Regulation

Technical

contacts: W. L. Jensen, NRR (301) 415-2856 Internet:wljenrc.gov

J. L. Birmingham, NRR (301) 415-2829 Internet:jlb4@nrc.gov

Attachments:

1. Table 1, 'Decay Heat Options Using ANS 5.1, 1979" 2. Table 2, "Relative

Importance

of Options 7200 Seconds (2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br />) After Reactor Shutdown" 3. Figure 1, "Peak Core' Cladding Temperature

Calculated

by ORIGEN" and Figure 2, "Peak Core Cladding Temperature

Calculated

by ANS 5.1" 4. List of Recently Issued NRC Information

Notices Reference: "American

National Standard for Decay Heat Power in Light Water American Nuclear Society Standards

Committee

Working Group, ANS August 29, 1979.Reactors," 5.1, Approved 44A0eiIII

Attachment

1 IN 96-39 July 5, 1996 Table 1. Decay Heat Options Using ANS 5.1, 1979 l I l l Power l Fissile Codes Actinides

R-Factor G-Factor Si History Elements Vendor Yes 0.6 Not ANS 1.347 3 Yrs. 3 RELAP 1 No NA MAX NA Infinite All_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _U 2 3 5 RELAP 2 Yes 1.0 MAX NA Infinite All_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ ___ ___U 2 3 5 RELAP 3 No NA No NA Infinite All_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _U 2 3 5 MELCOR Yes 0.526 Yes 0.713 1.6 Yrs. 3 TRAC No NA Yes 1.0 Infinite All_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ __I_ U 2 3 5 Notes: Actinides:

Neutron adding to the total capture by U238 produces U239 which decays into Np239 which also decays, decay heat. Not all the above code inputs included actinide decay.R-factor:

The actinide production

multiplier.

The standard states that the value of R shall be supplied and justified

by the user.G-factor:

A decay heat multiplier

to account for the effect of neutron capture in fission products.

The standard provides the option of using a maximum value table for the G-factor or a best estimate equation for the first 10,000 seconds.Si: Fissions per initial fissile atom. Si is a multiplier

applied to the G-factor equation.Power History: Length of full-power

operation

before shutdown.Fissile Elements:

The standard permits decay power to be fractionally

attributed

to the fission products of 3 fissile isotopes U235, U238, and Pu239. The vendor input attributed

the fractional

fission product power as 0.487 from U235, 0.069 from U238, and 0.443 from U239. The fractional

fission product power input to MELCOR was 0.647 from U235, 0.0425 from U238, and 0.31 from Pu239. The other code inputs assumed all fission product power came from U235.

Attachment

2* IN 96-39 July 5, 1996 Table 2. Relative Importance

of Options 7200 Seconds (2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br />) After Reactor Shutdown Complete Set For: Options as InDut and Varied Decay Heat in MWT MELCOR MELCOR assumptions (see Table 1) 20.70______________________________________________________________________________

Increase R from .526 to .6 21.03 Increase Si from .713 to 1.347 21.13 Operation

time from 1.6 years to 3 years 21.40 Vendor fissile isotopes 21.12 Vendor heavy element equation 21.86 Vendor code Vendor G-factor equation 22.15-__ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ -_ _ _ _ _ _ _ _ _ _ _ _ANS 5.1 G-factor and heavy element eqs. 21.12 No actinides

18.65 Gmax rather than equation 19.44 Infinite operation

20.53 RELAP 1 All fission from U235 22.02 ----------------

RELAP 2 Add actinides

with R=1 26.13 RELAP 3 Remove actinides

and G-factor 20.82 TRAC Include G-factor equation with Si-i 22.02 Note: This table illustrates

the relative importance

of the various options contained

in the 1979 ANS 5.1 standard.

Starting with the decay heat rate calculated

by MELCOR using the inputs listed in Table 1, the options were changed in sequence to those used in the vendor computer code. The options were then changed to those used in the RELAP 1 analyses, the RELAP 2 analyses, the RELAP 3 analyses, and the TRAC analyses.

.i Figure 1 Peak Core Cladding Temperature

1400.0 1200.0 2'CD E 0 1000.0 800.0 Attachment

3 IN 96-39 July 5, 1996- 12000.0 600.0 L 400.0 -0.0 4000.0 8000.0 Time (s)1400.0 Figure 2 Peak Core Cladding Temperature

Ug 1L&... A& IC C 4 var.qy ntIvat 04 1200.0 1-Infinite Operati All U235 Fissic G=Gmax Actinides

with I£'0 a E 02 1000.0 800.0 ,n..ulLwu

U)Y MIND ;.. I on in 1 R=1/600.0 400.0 L 0.C.........I D 4000.0 8000.0 12000.0 Time (s)

Attachment

4 IN 96-39 July 5, 1996 LIST OF RECENTLY ISSUED NRC INFORMATION

NOTICES Information

Date of Notice No. Subject Issuance Issued to 96-38 96-37 96-36 96-35 96-34 Results of Steam Generator Tube Examinations

Inaccurate

Reactor Water Level Indication

and Inad-vertent Draindown

During Shutdown Degradation

of Cooling Water Systems Due to Icing Failure of Safety Systems on Self-Shielded

Irradia-tors Because of Inadequate

Maintenance

and Training Hydrogen Gas Ignition during Closure Welding of a VSC-24 Multi-Assembly

Sealed Basket Erroneous

Data From Defective

Thermocouple

Results in a Fire Implementation

of 10 CFR 50.55a(g)

(6) (ii)(A),"Augmented

Examination

of Reactor Vessel" Cross-Tied

Safety Injec-tion Accumulators

Inaccuracy

of Diagnostic

Equipment

for Motor-Operated Butterfly

Valves Requirements

in 10 CFR Part 21 for Reporting

and Evaluating

Software Errors 06/21/96 06/18/96 06/12/96 06/11/96 05/31/96 05/24/96 06/05/96 05/22/96 05/21/96 05/20/96 All holders of OLs or CPs for pressurized

water reactors All pressurized

water reactor facilities

holding an operating

license or a construction

permit All holders of OLs or CPs for nuclear power reactors All U.S. Nuclear Regulatory

Commission

irradiator

licensees

and vendors All holders of OLs or CPs for nuclear power reactors All material and fuel cycle licensees

that monitor tem-perature with thermocouples

All holders of OLs or CPs for nuclear power reactors All holders of OLs or CPs for pressurized

water reactors All holders of OLs or CPs for nuclear power reactors All holders of OLs or CPs for nuclear power reactors 96-33 96-32 96-31 96-30 96-29 OL = Operating

License CP -Construction

Permit

IN 96-39 July 5, 1996 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

Office of Nuclear Reactor Regulation (NRR) project manager.OrfIoaw Stgned by Brin K. Grimes Brian K. Grimes, Acting Director Division of Reactor Program Management

Office of Nuclear Reactor Regulation

Technical

contacts: W. L. Jensen, NRR (301) 415-2856 Internet:wl

jnrc.gov J. L. Birmingham, NRR (301) 415-2829 Internet:jlb4@nrc.gov

Attachments:

1. Table 1, 'Decay Heat Options Using ANS 5.1, 1979" 2. Table 2, 'Relative

Importance

of Options 7200 Seconds (2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br />) After Reactor Shutdown" 3. Figure 1, "Peak Core Cladding Temperature

Calculated

by ORIGEN" and Figure 2, "Peak Core Cladding Temperature

Calculated

by ANS 5.1" 4. List of Recently Issued NRC Information

Notices Reference: "American

National Standard for Decay Heat Power in Light Water American Nuclear Society Standards

Committee

Working Group, ANS August 29, 1979.Reactors," 5.1, Approved*See previous concurrence

Tech Editor reviewed and concurred

on 03/19/96 DOCUMENT NAME: 96-39. IN To eceiw a copy of this document, hdMcata In the box: 'C' -Copy wlo attechmentenclosure

E' -Copy w/attachment/.nclosure

W -No copy"""7 OFFICE TECH CONTS I C:PECB:DRPM

I I 1II NAME WLJensen*

AEChaffee*

m lJLBirmingham*

C ,v_, DATE 04/02/96 05/16/96 07/1 /96 1 1 03/19/96 1 [ 1 1 __

IN 96-xx July xx, 1996 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

Office of Nuclear Reactor Regulation (NRR) project manager.Brian K. Grimes, Acting Director Division of Reactor Program Management

Office of Nuclear Reactor Regulation

Technical

contacts: W. L. Jensen, NRR (301) 415-2856 Internet:wlj~nrc.gov

J. L. Birmingham, NRR (301) 415-2829 Internet:jlb4enrc.gov

Attachments:

1. Table 1, "Decay Heat Options Using ANS 5.1, 1979" 2. Table 2, "Relative

Importance

of Options 7200 Seconds (2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br />) After Reactor Shutdown" 3. Figure 1, "Peak Core Cladding Temperature

Calculated

by ORIGEN" and Figure 2, "Peak Core Cladding Temperature

Calculated

by ANS 5.1" 5. List of Recently Issued NRC Information

Notices Reference: "American

National Standard for Decay Heat Power in Light Water Reactors," American Nuclear Society Standards

Committee

Working Group ANS 5.1, Approved August 29, 1979.*See previous concurrence

OFFICE SASG:DSSA:NRR

SASG:DSSA:NRR

l D/DSSA:NRR

NAME l WLJensen*

RCaruso* l GMHolahan*

DATE 04/02/96 04/04/96 04/30/96 OFFICE TECHED:RPB

1 PECB:DRPM:NRR

_ C/PECB:DRPM:NRR

AD/DRPM:NRR

NAME B. Calure* JBirmingham*

AEChaffee*

BKGrimes DATE 03/19/96 103/19/96

1 05/16/96 1 / /96 OFFICIAL DOCUMENT NAME: G:\JLB\DKAY4.IN

m,4A

IN 96-xx June xx, 1996 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

Office of Nuclear Reactor Regulation (NRR) project manager.Brian K. Grimes, Acting Director Division of Reactor Program Management

Office of Nuclear Reactor Regulation

Technical

contacts: W. L. Jensen, NRR (301) 415-2856 Internet:wljenrc.gov

J. L. Birmingham, NRR (301) 415-2829 Internet:jlb4@nrc.gov

Attachments:

1. Table 1, Decay Heat Options Using ANS 5.1, 1979." 2. Table 2, Relative Importance

of Options 7200 Seconds (2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br />) After Reactor Shutdown'3. Figure 1, "Peak Core Cladding Temperature

Calculated

by ORIGEN." 4. Figure 2, 'Peak Core Cladding Temperature

Calculated

by ANS 5.1.'5. List of Recently Issued NRC Information

Notices Reference:

American National Standard for Decay Heat Power in Light Water Reactors," American Nuclear Society Standards

Committee

Working Group ANS 5.1, Approved August 29, 1979.*Sep nrpvious concurrence

OFFICE SASG:DSSA:NRR

SASG:DSSA:NRR

D/DSSA:NRR

NAME WLJensen*

RCaruso* GMHolahan*

nATF 0a4/02/96 04/04/96 04/30/96_.-OFFICE TECHED:RPB

PECB:DRPM:NRR

C/PECB:DRPM:NRR

AD/DRPM:NRR

NAME B. Calure* JBirmingham*

AEChaffeeX

BKGrimes DATE 03/19/96 .03/19/96 .05//b/96 1 05/ /96)FFICIAL DOCUMENT NAME: G:\JLb\UKAY4.IN

mtEA,

K-,-IN 96-xx May xx, 1996 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

Office of Nuclear Reactor Regulation (NRR) project manager.Brian K. Grimes, Acting Director Division of Reactor Program Management

Office of Nuclear Reactor Regulation

Technical

contacts: W. L. Jensen, NRR (301) 415-2856 Internet:wl

jnrc.gov J. L. Birmingham, NRR (301) 415-2829 Internet:jlb4@nrc.gov

Attachments:

1. Table 1, "Decay Heat Options Using ANS 5.1, 1979." 2. Table 2, "Relative

Importance

of Options 7200 Seconds (2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br />) After Reactor Shutdown'3. Figure 1, *Peak Core Cladding Temperature

Calculated

by ORIGEN." 4. Figure 2, "Peak Core Cladding Temperature

Calculated

by ANS 5.1." 5. List of Recently Issued NRC Information

Notices Reference:

'American

National Standard for Decay Heat Power in Light Water Reactors," American Nuclear Society Standards

Committee

Working Group ANS 5.1, Approved August 29, 1979.*Sge ntrvinut concurrence

OFFICE SASG:DSSA:NRR

SASG:DSSA:NRR

D/DSSA:NRR

NAME WLJensen*

RCaruso* GMHolahan*

DATE 4T\1o 04/02/96 04/04/96 04/30/96 OFFICE TECHED:RPB

1 PECB:DRPM:NRR

CAE A AD/DRPM:NRR

NAME B B. Calure* JBirmingham*

AE a fel BKGrimes DATE l 03/19/96 03/19/96 0 5/14/96 ; 05/ /96-rr .. ---r ... --.~. -t -.gA I JFIHUAL WLUMNI KAM: U: \-JLt1\UA1Uq.

IN AV0en&

K>-IN 96-xx May xx, 1996 This information

notice requires no specific action or written response.

If you have any questions

about the information

in this notice, please conta t one of the technical

contacts listed below or the appropriate

Office of Nuclear Reactor Regulation (NRR) project manager.Brian K. Grimes, Acting Dire or Division of Reactor Progra Management

Office of Nuclear Reacto egulation Technical

contacts:

W. L. Jensen, NRR (301) 415-2856 Internet:wlj@nrc.gov

J. L. Birmingham, NRR (301) 415-2829 Internet:jlb4@nrc.gov

Attachments:

1. Table 1, "Decay Heat Options Using ANS 5 , 1979." 2. Table 2, 'Relative

Importance

of Option 7200 Seconds (2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br />) Aft Reactor Shutdown." 3. Figure 1, "Peak Core Cladding Temper ure Calculated

by ORIGEN." 4. Figure 2, 'Peak Core Cladding Tegmp ature Calculated

by ANS 5.1.'5. List of Recently Issued NRC 19o( ation Notices Reference:

'American

National Standard fg ecay Heat Power in Light Water Reactors," American Nuclear Society Sta d ds Committee

Working Group ANS 5.1, Approved August 29, 1979.*See previous concu e OFFICE SASG:DA:NRR

SASG:DSSA:NRR

D/DSSA:NRR

NAME WLJfaen* I RCaruso* GMHolahan*

DATE I 04 2/96 1 04/04/96 I 04/30/96.1. .. .*OFFICE f ECHED:RPB

PECB:DRPM:NRR

C/PECB:DRPM:NRR

AD/DRPM:NRR

NAME- / B. Calure* JBirmingham*

AEChaffee

BKGrimes DATE / 03/19/96 03/19/96 05/ /96 05/ /96 bew Tl Ir-luzT l u .s .. -1 -1 %vV UFFIGJAL UDUMEIN NAME: W \)Lb \UKAY4. 11 &W

IN 96-xx May xx, 1996 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

Office of Nuclear Reactor Regulation (NRR) project manager.Brian K. Grimes, Acting Director Division of Reactor Program Management

Office of Nuclear Reactor Regulation

Technical

contacts: W. L. Jensen, NRR (301) 415-2856 Internet:wlj@nrc.gov

J. L. Birmingham, NRR (301) 415-2829 Internet:jlb4@nrc.gov

Attachments:

1. Table 1, "Decay Heat Options Using ANS 5.1, 1979." 2. Table 2, wRelative

Importance

of Options 7200 Seconds (2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br />) After Reactor Shutdown.'

3. Figure 1, wPeak Core Cladding Temperature

Calculated

by ORIGEN.3 4. Figure 2, uPeak Core Cladding Temperature

Calculated

by ANS 5.1." 5. List of Recently Issued NRC Information

Notices Reference: "American

National Standard for Decay Heat Power in Light Water Reactors," American Nuclear Society Standards

Committee

Working Group ANS 5.1, Approved August 29, 1979.A*See Drevious concurrence

OFFICE SASG:DSSA:NRR

SASG:DSSA:NRR

D1XaS.a NAME W W ensen RCaruso k M -ahan DATE 04/02/96 04/04/96 i4/ 0/96 OFFICE TECHED:RPB

PECB:DRPM:NRR

C/PECB:DRPM:NRR

D/DRPM:NRR

NAME B. Calure* JBirmingham*

AEChaffee

DLCrutchfield

DATE 1 03/19/96 03/19/96 1 04/ /96 j 04/ /96 UN ILIAL UL r *:- W..DtuF in WFICIAL UUCUMMN NAM: U: XJLt$UKU>Y4.

IrN

IN 96-xx April xx, 1996 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

Office of Nuclear Reactor Regulation (NRR) project manager.Denni .Crutchfield, Director Division f Reactor Program Management

Office of lear Reactor Regulation

Technical

contacts:

W. L. Jensen, NRR (301) 415-2856 Internet:wlj~nrc.gov

J. L. Birmingham, NRR (301) 415-2829 Internet:jlb4@nrc.gov

Attachments:

1. Table 1, Decay Heat Options Using ANS 5.1, 1979.0 2. Table 2, "Relative

Importance

of Options 7200 Seconds (2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br />) After Reactor Shutdown." 3. Figure 1, NPeak Core Cladding Temperature

Calculated

by ORIGEN." 4. Figure 2, "Peak Core Cladding Temperature

Calculated

by ANS 5.1." 5. List of Recently Issued NRC Information

Notices Reference:

American National Standard for Decay Heat Power in Light Water Reactors," American Nuclear Society Standards

Committee

Working Group ANS 5.1, Approved August 29, 1979.*See previous concurrence

OFFICE SASG:DSSA!RR

SASQ: PSSA:NRR D/DSSA:NRR

NAME jW Jenkeg( RCaJ & GMHolahan DATE I 04/2 /96 I 04/10/96 I 04/ /96 OFFICE TECHED:RPB

PECB:DhPM:NRR

C/PECB:DRPM:NRR

D/DRPM:NRR

NAME B. Calure* JBirmingham*

AEChaffee

DLCrutchfield

DATE 03/19/96 03/19/96 04/ /96 04/ /96 FFICIAL DOCUMENT NAME: G:\JLB\UKAY4.IN

5. List of RecentlySosued

NRC Information

Notices Reference:

1. "American

National Standard for Decay Heat Power in Light Water Reactors," American Nuclear Society Standards

Committee

Working Group ANS 5.1. Approved August 29. 1979.OFFICE SASG:DSSA:NRR

SASG:DSSA:NRR

D/DSSA:NRR

NAME WLJensen RCaruso GMHolahan DATE 03/ /96 03/ /96 03/ /96 03/ /96 OFFICE TECHED:RPB

PECB:DRPM:NRR

C/PECB:DRPM:NRR

D/DRPM:NRR

NAME JBirmingham

AEChaffee

DLCrutchfield

DATE 03//7/96 03/ /96 03/ /96 03/ /96 OFFICIAL DOCUMENT NAME: G:\JLB\DECAY

HT.JLB


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