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

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
Issue date:	07/05/1996
From:	Grimes B; 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,, RELAP2, and RELAP in the

following tables. The decay heat estimates in MWT calculated ?or 2 hours2.314815e-5 days 5.555556e-4 hours 3.306878e-6 weeks 7.61e-7 months

PD& IC ';cs 95-o3q 9(.oqoS

9606250199 1 A

O

0o 161b'~'k ussOAf

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

RELAP1 - 22.02 MWT

RELAP 2 - 26.13 MWT

RELAP3 - 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 5.555556e-4 hours 3.306878e-6 weeks 7.61e-7 months 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 RELAP2 . 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 5.555556e-4 hours 3.306878e-6 weeks 7.61e-7 months ) 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 Reactors,"

American Nuclear Society Standards Committee Working Group, ANS 5.1, Approved

August 29, 1979.

/, III CT,09we,

44A0ei

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 RELAP1 No NA MAX NA Infinite All

_ __ _ __ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _U 23 5 RELAP 2 Yes 1.0 MAX NA Infinite All

_ _ _ _ _ _ _ _ _ _ _ __ __ _ ___ ___U 235 RELAP3 No NA No NA Infinite All

_ _ __ __ _ _ _ _ __ __ _ _ __ _ __ _ _ _ _ _ _ _ _ _ _ _ _U 23 5 MELCOR Yes 0.526 Yes 0.713 1.6 Yrs. 3 TRAC No NA Yes 1.0 Infinite All

__ _ _ __ _ __ _ _ __ _ __ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ __I_ U235 Notes:

Actinides: Neutron capture by U238 produces U239 which decays into Np239 which also decays, adding to the total 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 5.555556e-4 hours 3.306878e-6 weeks 7.61e-7 months ) 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 RELAP1 All fission from U235 22.02 ----------------

RELAP2 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 RELAP1 analyses, the RELAP2 analyses, the RELAP3 analyses, and the TRAC analyses.

Attachment 3

.i IN 96-39 Figure 1 Peak Core Cladding Temperature July 5, 1996

1400.0 - 1200.0

2' 1000.0

CD

E

0 800.0

600.0 L

400.0 -

0.0 4000.0 8000.0 12000.0

Time (s)

Figure 2 Peak Core Cladding Temperature

1400.0

Ug

1L&... A& IC C 4 var.qy ntIvat 04,n..ulLwu U)Y MIND ;.. I

Infinite Operati on

1200.0 1- All U235 Fissicin 1 G=Gmax

Actinides with IR=1/

£' 1000.0

0

a

E

02 800.0

600.0

400.0 L . . . . . . . . .I

0.CD 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 Results of Steam Generator 06/21/96 All holders of OLs or CPs

Tube Examinations for pressurized water

reactors

96-37 Inaccurate Reactor Water 06/18/96 All pressurized water

Level Indication and Inad- reactor facilities holding

vertent Draindown During an operating license or a

Shutdown construction permit

96-36 Degradation of Cooling 06/12/96 All holders of OLs or CPs

Water Systems Due to Icing for nuclear power reactors

96-35 Failure of Safety Systems 06/11/96 All U.S. Nuclear Regulatory

on Self-Shielded Irradia- Commission irradiator

tors Because of Inadequate licensees and vendors

Maintenance and Training

96-34 Hydrogen Gas Ignition 05/31/96 All holders of OLs or CPs

during Closure Welding for nuclear power reactors

of a VSC-24 Multi-Assembly

Sealed Basket

96-33 Erroneous Data From 05/24/96 All material and fuel cycle

Defective Thermocouple licensees that monitor tem- Results in a Fire perature with thermocouples

96-32 Implementation of 10 CFR 06/05/96 All holders of OLs or CPs

50.55a(g) (6)(ii)(A), for nuclear power reactors

"Augmented Examination

of Reactor Vessel"

96-31 Cross-Tied Safety Injec- 05/22/96 All holders of OLs or CPs

tion Accumulators for pressurized water

reactors

96-30 Inaccuracy of Diagnostic 05/21/96 All holders of OLs or CPs

Equipment for Motor- for nuclear power reactors

Operated Butterfly Valves

96-29 Requirements in 10 CFR 05/20/96 All holders of OLs or CPs

Part 21 for Reporting and for nuclear power reactors

Evaluating Software Errors

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 5.555556e-4 hours 3.306878e-6 weeks 7.61e-7 months ) 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 Reactors,"

American Nuclear Society Standards Committee Working Group, ANS 5.1, Approved

August 29, 1979.

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 91 OFFICE TECH CONTS I C:PECB:DRPM I I 1II

NAME WLJensen* AEChaffee* m

lJLBirmingham* C ,v_,

07/1 /96

1 DATE 04/02/96

103/19/96 105/16/96 [ 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 5.555556e-4 hours 3.306878e-6 weeks 7.61e-7 months ) 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 5.555556e-4 hours 3.306878e-6 weeks 7.61e-7 months ) 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 5.555556e-4 hours 3.306878e-6 weeks 7.61e-7 months ) 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 04/02/96 04/04/96 04/30/96 4T\1o

OFFICE

NAME

TECHED:RPB

B

B. Calure*

1 PECB:DRPM:NRR

JBirmingham* AE

CAE A

a fel

AD/DRPM:NRR

BKGrimes

DATE l 03/19/96 03/19/96 05/14/96 ; 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 5.555556e-4 hours 3.306878e-6 weeks 7.61e-7 months ) 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 .1. I04 .. *2/96

. 1 04/04/96

I 04/30/96 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 Tl

bewIr-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 5.555556e-4 hours 3.306878e-6 weeks 7.61e-7 months ) After

Reactor Shutdown.'

3

3. Figure 1, wPeak Core Cladding Temperature Calculated by ORIGEN.

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.

See Drevious concurrence A

OFFICE SASG:DSSA:NRR SASG:DSSA:NRR D1XaS.a

NAME W Wensen 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 103/19/96 03/19/96 1 04/ /96 j 04/ /96 UNILIAL*:-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 5.555556e-4 hours 3.306878e-6 weeks 7.61e-7 months ) 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 I04/2 /96 I04/10/96 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

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

Addressees

Purpose

Description of Circumstances

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