ML19253C300: Difference between revisions
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l o l 819 l lV LICENSEE 7 lA lN CODE lA lS l1 l@15 14 | l o l 819 l lV LICENSEE 7 lA lN CODE lA lS l1 l@15 14 | ||
]0 }- DD46D l@l4l1 l1 l1 l1 JOLIJ @ | ]0 }- DD46D l@l4l1 l1 l1 l1 JOLIJ @ | ||
LICENSE NUMBER 25 2ts LICENSE TYPE JO b7 CAT 58 CON'T | LICENSE NUMBER 25 2ts LICENSE TYPE JO b7 CAT 58 CON'T loIll 7 8 5ouRC l60 L l@l 61 0 l 5 DOCKET l 0 l NUMBER 0 l 0 l 3 l 683 l 698 @lEVENT 1 l1D ATE l0 l6 l 7 l9 l@l1lIl2]0l7l9l@ | ||
loIll 7 8 5ouRC l60 L l@l 61 0 l 5 DOCKET l 0 l NUMBER 0 l 0 l 3 l 683 l 698 @lEVENT 1 l1D ATE l0 l6 l 7 l9 l@l1lIl2]0l7l9l@ | |||
74 75 REPCHT DATE 80 EVENT DESCRIPTION ATJD PROBABLE CONSEQUENCES h o 2 l During a review of system operation, it was discovered that desian deficiencies could I o a l result in ESF equipment operating less conservatively than assumed in the FSAR. I o 4 l Specifically: systems returning to non-safety mode following reset of ESF: and I o s I time delay start systems not going to completion following reset of ESF. HV, RS I O 6 l and SW sfStems are af fected . The safety of the public was not af fected . Reportable l l o l 7 l l pursuant to T.S. 6.9.1.8.1. I o a I l | 74 75 REPCHT DATE 80 EVENT DESCRIPTION ATJD PROBABLE CONSEQUENCES h o 2 l During a review of system operation, it was discovered that desian deficiencies could I o a l result in ESF equipment operating less conservatively than assumed in the FSAR. I o 4 l Specifically: systems returning to non-safety mode following reset of ESF: and I o s I time delay start systems not going to completion following reset of ESF. HV, RS I O 6 l and SW sfStems are af fected . The safety of the public was not af fected . Reportable l l o l 7 l l pursuant to T.S. 6.9.1.8.1. I o a I l | ||
80 7 8 9 SYSTEM CAUSE CAUSE COMP. VALVE CODE CODE SLSCODE COVPONENT CODE SUBCODE SU8 CODE O 9 I S l H l@ ]@ l A l@ l Z l Zl Z l Z l Z l Z l@ y@ y @ 20 7 8 9 10 11 12 13 18 19 | 80 7 8 9 SYSTEM CAUSE CAUSE COMP. VALVE CODE CODE SLSCODE COVPONENT CODE SUBCODE SU8 CODE O 9 I S l H l@ ]@ l A l@ l Z l Zl Z l Z l Z l Z l@ y@ y @ 20 7 8 9 10 11 12 13 18 19 | ||
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41 42 43 44 Zl9l9 9l@ 47 CAusE DEsCoisn0'4 ANc C0==E:mvE ACTIONS @ | 41 42 43 44 Zl9l9 9l@ 47 CAusE DEsCoisn0'4 ANc C0==E:mvE ACTIONS @ | ||
1 O l 1'he axact cause for the nonconservative operation of these ESF Systems is unknown at l 1 i this time, however, a design deficiency by the architect engineer is suspected . The I | 1 O l 1'he axact cause for the nonconservative operation of these ESF Systems is unknown at l 1 i this time, however, a design deficiency by the architect engineer is suspected . The I | ||
, , l problem is being evaluated to determine the corrective actions required. I i 3 l 1 4 l 7 8 9 80 ST S %*CAER OTH ER STATUS is O RY DISCOVERY DESCRIPTION l i I 5 I (,H JQ l 0l 0 l 0 l@l NA | , , l problem is being evaluated to determine the corrective actions required. I i 3 l 1 4 l 7 8 9 80 ST S %*CAER OTH ER STATUS is O RY DISCOVERY DESCRIPTION l i I 5 I (,H JQ l 0l 0 l 0 l@l NA l lAl@l Review of System Operation l ACTIVITY CONTENT RELEASED OF PELEASE AVCUNT OF ACTIVITY LOCATION OF RELEASE NA NA l liIsl 8I 9Zi @ l Zl @ l 7 to 11 44 l l 45 80 PERSONNEL Ex*C5UR ES NUVBER TvPE D E S C A'*TIO N i 7 I 9 01 Ol@l Zl@l - I PER3ONNEL INr 'ES NUV8ER DESCRIPTION li is l 01 Ol ^ I l@l12 7 8 9 11 LOSS OF ( R DAMAGE To F A CILITY \ | ||
l lAl@l Review of System Operation l ACTIVITY CONTENT RELEASED OF PELEASE AVCUNT OF ACTIVITY LOCATION OF RELEASE NA NA l liIsl 8I 9Zi @ l Zl @ l 7 to 11 44 l l 45 80 PERSONNEL Ex*C5UR ES NUVBER TvPE D E S C A'*TIO N i 7 I 9 01 Ol@l Zl@l - I PER3ONNEL INr 'ES NUV8ER DESCRIPTION li is l 01 Ol ^ I l@l12 7 8 9 11 LOSS OF ( R DAMAGE To F A CILITY \ | |||
'}')6 | '}')6 | ||
)b 80 TYPE DESCRIPTION 1 i ' | )b 80 TYPE DESCRIPTION 1 i ' | ||
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Supply to Air Cooling coils, MOV-SW-110A,B & 114A,B Supply to Air Cooling Coils, TV-SW-101A,B Valves reopen to provide service water to the containment air coolers after CDA signal is reset. This occurs only when the control switch for cooling had previously been placed in the service water position. Normal cooling of the recirculation air cooler is with chiller water. | Supply to Air Cooling coils, MOV-SW-110A,B & 114A,B Supply to Air Cooling Coils, TV-SW-101A,B Valves reopen to provide service water to the containment air coolers after CDA signal is reset. This occurs only when the control switch for cooling had previously been placed in the service water position. Normal cooling of the recirculation air cooler is with chiller water. | ||
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==Attachment:== | ==Attachment:== | ||
Latest revision as of 01:32, 2 February 2020
| ML19253C300 | |
| Person / Time | |
|---|---|
| Site: | North Anna  |
| Issue date: | 11/20/1979 |
| From: | Cartwright W VIRGINIA POWER (VIRGINIA ELECTRIC & POWER CO.) |
| To: | NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II) |
| Shared Package | |
| ML19253C295 | List: |
| References | |
| LER-79-141-01T, LER-79-141-1T, NUDOCS 7911300472 | |
| Download: ML19253C300 (3) | |
Text
. .
(7 77)
'
- LICENSEE EVENT REPORT (PLEASE PRINT OR TYPE ALL REQUIRED INFORMATION)
CONTROL BLOCK: l 1
l l l l l lh 6
l o l 819 l lV LICENSEE 7 lA lN CODE lA lS l1 l@15 14
]0 }- DD46D l@l4l1 l1 l1 l1 JOLIJ @
LICENSE NUMBER 25 2ts LICENSE TYPE JO b7 CAT 58 CON'T loIll 7 8 5ouRC l60 L l@l 61 0 l 5 DOCKET l 0 l NUMBER 0 l 0 l 3 l 683 l 698 @lEVENT 1 l1D ATE l0 l6 l 7 l9 l@l1lIl2]0l7l9l@
74 75 REPCHT DATE 80 EVENT DESCRIPTION ATJD PROBABLE CONSEQUENCES h o 2 l During a review of system operation, it was discovered that desian deficiencies could I o a l result in ESF equipment operating less conservatively than assumed in the FSAR. I o 4 l Specifically: systems returning to non-safety mode following reset of ESF: and I o s I time delay start systems not going to completion following reset of ESF. HV, RS I O 6 l and SW sfStems are af fected . The safety of the public was not af fected . Reportable l l o l 7 l l pursuant to T.S. 6.9.1.8.1. I o a I l
80 7 8 9 SYSTEM CAUSE CAUSE COMP. VALVE CODE CODE SLSCODE COVPONENT CODE SUBCODE SU8 CODE O 9 I S l H l@ ]@ l A l@ l Z l Zl Z l Z l Z l Z l@ y@ y @ 20 7 8 9 10 11 12 13 18 19
,,,, SEQU ENTI AL oCCURAENCE REPORT REVISION LER RO E'.ENT Y E AR R EPORT NO. CODE TYPE NO.
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_2' 22 20 24 26 27 23 29 30 31 32 ACTION FUTUAE EE8ECT C.'OCAN ATTACHV E NT NPR D-4 PRIME COMP. COMPONENT TAKEN ACTION cN PL ANT YET=CO HOURS SUBVITTED FORMbuB. SUPPLIER MANUFACTURER l33Xlgl34 Fj,y lZ@
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41 42 43 44 Zl9l9 9l@ 47 CAusE DEsCoisn0'4 ANc C0==E:mvE ACTIONS @
1 O l 1'he axact cause for the nonconservative operation of these ESF Systems is unknown at l 1 i this time, however, a design deficiency by the architect engineer is suspected . The I
, , l problem is being evaluated to determine the corrective actions required. I i 3 l 1 4 l 7 8 9 80 ST S %*CAER OTH ER STATUS is O RY DISCOVERY DESCRIPTION l i I 5 I (,H JQ l 0l 0 l 0 l@l NA l lAl@l Review of System Operation l ACTIVITY CONTENT RELEASED OF PELEASE AVCUNT OF ACTIVITY LOCATION OF RELEASE NA NA l liIsl 8I 9Zi @ l Zl @ l 7 to 11 44 l l 45 80 PERSONNEL Ex*C5UR ES NUVBER TvPE D E S C A'*TIO N i 7 I 9 01 Ol@l Zl@l - I PER3ONNEL INr 'ES NUV8ER DESCRIPTION li is l 01 Ol ^ I l@l12 7 8 9 11 LOSS OF ( R DAMAGE To F A CILITY \
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)b 80 TYPE DESCRIPTION 1 i '
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,sSU3@%e'SCR,PraN @ 7oliaoo yJA 2 o L l NA l lllll l[lll l:3 68 69 80 + 1i, 7 8 9 to NAME OF PREPARER M- # N *""Inhe PHONE: 7 9 004-51_<1_
Virginia Electric and Power Company North Anna Power Station #1
Attachment:
Page 1 of 2 Docket No. 50-338 Report No. LER 79-141/0lT 0 Description of Event On November 6,1979, during a review of system operation following a review of system performance during a recent unit trip and subsequent safety injection, it was discovered that the control room air-operated dampers which isolate the control room from outside air on an SI signal return to their non-safety mode when the SI signal is reset. This is contrary to FSAR comment 7.4 which states that two actions are required to return ESF equipment to a non-safety feature mode. Specifically, it is accomplished by resetting the appropriate actuation signal and subsequently operating the control switch for the device.
A review was immediately initiated to determine if any other deficiencies e xis ted .
The following is a list of potential design deficiencies that were dis-covered.
The following systems return to their non-safety mode following reset of an ESF signal:
Centrol Rocm Habitability System (RV)
Supply Air Damper A0D-HV-160-1 Exhaust Air Damper A0D-HV-161-1 Dampers reopen af ter SI signal is reset.
Safecuards Area Ventilation System (HV)
Exhaust Air Dampers A0D-HV-128-1,-2,-3,-4 Filter Bank Dampers A0D-HV-107A-1, A-2, A-3, A-4,B-1,B-2,B~3, B-4 Dampers re-position to bypass filters af ter Containment Depressi eization Actuation (CDA) si;nal is reset.
Containment Ventilation System (HV)
Containment Recirculation Cooler Fan, 1-HV-F-1 A,-B Control Rod Drive Cooling Fan, 1-HV- F-3 7 A, B , C , D , E, F Fans restart af ter CDA signal is reset Service Water Systen (SW)
Supply to Air Cooling coils, MOV-SW-110A,B & 114A,B Supply to Air Cooling Coils, TV-SW-101A,B Valves reopen to provide service water to the containment air coolers after CDA signal is reset. This occurs only when the control switch for cooling had previously been placed in the service water position. Normal cooling of the recirculation air cooler is with chiller water.
1443 026
Attachment:
Page 2 of 2 The following systems do not go to completion if the CDA signal is reset prior to expiration of the starting time delay relay:
Recirculation Spray System (RS)
Outside Recirculation Spray Ibmp, 1-RS-P-2A, B Inside Recirculation Spray Pamp, 1-RS-P-1A, B Service Water System (SW)
RS Heat Exchanger Radiation Monitoring Sample Pumps, 1-SW-P-5, 6, 7, 2 Probable Consequences of Occurrence The reset capability of ESF signals is required to permit action in the post accident period. With the present design, the protective actions of the affected systems could be prevented or cancelled once the associated actuation signal is reset which is in noncompliance with IEEE Standards. The health and safety of the general public were not endangered by this event.
Unit 2 systems have the same reset design and are similarly affected.
Cause of Occurrence The cause of these discrepancies is not known at this time. However, it appears that they cay have resulted from a possible design deficiency by Stone and Webster.
Iemediate Corrective Action The problem is being evaluated by Engineering Services to determine the corrective actiocs required.
Scheduled Corrective Action The reset circuitry for the affected ESF equipment will be modified or redesigned, if required.
Actions Taken to Prevent Recurrence No further actions are required.
1443 027