ML20215H166
| ML20215H166 | |
| Person / Time | |
|---|---|
| Site: | Beaver Valley |
| Issue date: | 04/13/1987 |
| From: | Carey J DUQUESNE LIGHT CO. |
| To: | NRC OFFICE OF ADMINISTRATION & RESOURCES MANAGEMENT (ARM) |
| Shared Package | |
| ML20215H168 | List: |
| References | |
| 2NRC-7-077, 2NRC-7-77, TAC-62919, NUDOCS 8704200192 | |
| Download: ML20215H166 (6) | |
Text
c 345 2NRC-7-077 l
(4121393 7546 Heavet Valley No 2 Unit Protect Organisation Telecopy 1412) 393 7889 N poygnu April 13, 1987 n
Sh.ppiryport, PA 16077 United States Nuclear Regulator y Coninission ATIN:
Docuinent Contr 01 Desk Washington, DC 20$55 SutlJLC T:
Beaver Valley Power Station Unit No. 2 Docket ho. 50-412 SER Confirinator y llein #J6 Cor e Danage Asses 9nent Pr ocedur e ben t i einen :
Plea'.e find attached:
- 1) Cor e Darnage A,sessinent Ps otedur e; and 2)
Westinghouse Ownet 's Gi oup Post Accident Cor e Danage Asses 9nent Methodology f4)dtfled for BVPS.
Attachinent 1 is pr ovided to to,nplete SLk Conf irinator y iten ftJ6.
Attachnent 2 is pt ovided to give the basis for the Cor e Uainage Asses 9nent Protedute.
If you should have any question *,, pleine call M. A. N. UtCesat o at (412) 393 7742.
DUQULShL LlWii COMPANY
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benTor Vice President AND/Ije hk/Afip/ CURL /UMG At t aclebent AR/hAR cc:
Mr. P. T iin, Project Managet w/attachwnt Mr. J. UcalI, hdL Le. Residt'nt inspettot w/attathnent M*.. L. Prtvidy, NHL Resident inspector w/ at t at hn;en t thPO Hetor ds Center w/attatbnent naC neo,n.,nt Cent.oi o m w/att hmeot 9,i I )
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United States Nuclear Regulatory Connission Con e Damoge Assessment Pr ocedure Page 2 COMMONWEALTH OF PENNSYLVANIA )
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COUNTY OF BEAVER On this /
day of
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, before me, a Notary Public in and for said CMonwealth and County, personally appeared J.
J. Carey, Wio being duly swot n, deposed and said that (1) he is Senior Vice Pr esident of Duquesne Light, (2) he is duly authorized to execute and file the for egoing Submittal on behalf of said Company, and (3) the statenents set forth In the Submittal at e tv uo and cor rect to the best of his knowledge.
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l BVPS-1/BVPS-2 CM l
CHAPTER 6 P.A.S.S UNIT 2 f
l CORE DAMAGE ASSESSP2NT PROCEDURE l
f This procedure uses core exit thermocouple readings, reactor vessel level readings, 2RMR*206 and 2RMR*207 containment radiation monitor readings, containment hydrogen values and isotopic data obtained from the PASS to estimate the extent of core damage after an accident at Beaver Valley.
By using the Westinghouse Owners' Group Post Core Damage Assessment Methodology adapted for the Beaver Valley Plant, this procedure will differentiate the amount of core damage over seven broad regions:
a.
No Core Damage b.
0-50% Clad Failure c.
50-100% Clad Failure d.
0-50% Fuel Pellet Overtemperature e.
50-100% Fuel Pellet Overtemperature f.
0-50% Fuel Molt g.
50-100% Fuel Melt This procedure should only be used by personnel familiar with the limitations of the Core Damage Assessment Methodology (CDAM), and will normally be performed by the chemistry coordinator during activation of the Emergency Preparedness Plan.
A.
Reference 1.
Westinghouse Owners Group Post Core Damage Assessment Methodology (Modifind for BVPS), 1984.
2.
Post Accident Sampling Procedure B.
Instructions 1.
Perform an isotopic analysis on Post Accident Sample of the RCS, containment atmosphere and containment sump (if applicable).
2.
Correct each isotopic value for decay to time of reactor shutdown using the decay correction in Section 2.4.5.3 of the CDAM (p.32).
NOTE:
Inotopen listed as daughter products in Table 2-7 of the CDAM (p.33) must also be corrected for parent-daughter
- decay, 1 of 4 ISSUE 1 REVISION 0
- ~. - - -
1 BVPS-1/BVPS-2 CM CHAPTER 6 P.A.S.S.
UNIT 2 CORE DAMAGE ASSESSMENT PROCEDURE (Continued) 3.
The decay corrected specific activity of each isotope obtained in step 2 should now be corrected for pressure and temperature as described in Section 2.4.5.2 of the CDAM (p.
29).
4.
The adjusted specific activity of each isotope obtained in step 3 can now be used to determine the total activity of j
i each isotope in the RCS, containment atmosphere, and the containment sump (if applicable). Multiply the adjusted specific activity of each isotope in each medium (RCS, l
containment atmosphere, or containment sump) by the mass in l
each medium as described in Section 2.4.5.2 of the CDAM (p.
l 29).
l 5.
Determine the total activity of each isotope released by
(-
adding the activities of the isotope in the RCS, containment atmosphere and containment sump.
6.
Calcuate the total activity of each isotope available in the core at time of plant shutdown by multiplying the fuel pellet inventory of each isotope in Table 2-2 of the CDAM (p. 6) by l
the power correction factor described in Section 2.3.1 of the CDAM (p. 7).
7.
Calculate the percentage of each isotope released by dividing the values obtained of each isotope in step 5 by the values obtained for that isotope in step 6, and multiplying that value times 100%.
8.
The percent inventory released determined in step 7 can then be used to determines a.
% Clad Damage - Use Figures 2-2 through 2-9 of the CDAM (p. 15 through 22) t b.
% Fuel Overtemperature - Use Figures 2-11 and 2-12 of the CDAM (p. 41 and 42)
(
l c.
% Fuel Malt - Use Figures 2-13 through 2-15 of the CDAM p
(p. 45 through 47) l f
I 2 of 4 ISSUE 1
(
REVISION 0 l
f L.
BVPS-1/BVPS-2 CM CHAPTER 6 P.A.S.S.
UNIT 2 CORE DAMAGE ASSESSMENT PROCEDURE (Continued) 9.
Auxiliary indicators can now be used to confirm the values calculated in step 8:
a.
Core exit thermocouple readings - (CDAM Section 3.2, P.
- 53) temperatures greater than 1300F indicate the likelihood of clad damage. Use Table 4-1 of the CDAM (p. 63).
b.
Reactor vessel level indication - (CDAM 3.2, P. 53) if RVLIS indicates less than 3.5 feet collapsed liquid level in the core, core uncovery has taken place, and core damage may have occurred depending on time of uncovery.
If RVLIS level is between 3.5 feet collapsed liquid level and the top of the core, core exit thermocouples should be used to determine if the core is uncovered.
The presence of superheated steam temperatures indicates that the core is uncovered.
c.
Containment Radiation Monitor (CDAM Section 3.3, P.
56). Calculate the normalized gamma exposure rate as follows:
R/hr-MWt = 2RMR*206 or 2RMR*207 reading x 0.9 2652 Use this value with Figure 3-3 of the CDAM (P. 60) to calculate % Noble Gas Release.
In general:
1)
Less than 0.3% Noble Gas Release - Indicative of Clad Failures 2)
Between 0.3% and 52% Noble Gas Release - Indicative of Fuel Overtemperature Conditions 3)
More than 52% Noble Gas Release - Indicative of some core melt d.
Containment Hydrogen - (CDAM Section 3.1, P. 49) using the Containment Hydrogen Monitors, obtain the % hydrogen present in containment. Use Table 4-1 of the CDAM (p.
- 63) to classify the amount of core damage.
3 of 4 ISSUE 1 REVISION O
)
BVPS-1/BVPS-2 CM CHAPTER 6 P.A.S.S.
UNIT 2 CORE DAMAGE ASSESSMENT PROCEDURE (Continued) 10.
Using the values obtained in step 8, as well as the values obtained in step 9, use Table 4-1 of the CDAM (p.
- 63) to differentiate between the various core damage states. As many indicato'rs as possible should be used.
Because of overlapping values of release and potential simultaneous conditions of clad damage, overtemperature, and/or core melt, considerable judgement must be applied in making a final determination.
1 l
4 of 4 ISSUE 1 REVISION O
. _.