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| | number = ML111990346 | | | number = ML111990346 |
| | issue date = 07/28/2011 | | | issue date = 07/28/2011 |
| | title = 07/28/2011 Meeting Presentation, Prairie Island Nuclear Generating Plant - Failure to Maintain the Train a and B Direct Current Electrical Power Subsystems Operable | | | title = Meeting Presentation, Prairie Island Nuclear Generating Plant - Failure to Maintain the Train a and B Direct Current Electrical Power Subsystems Operable |
| | author name = | | | author name = |
| | author affiliation = Xcel Energy | | | author affiliation = Xcel Energy |
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| {{#Wiki_filter:N R C R e g i o n I I I R e g u l a t o r y C o n f e r e n c e F a i l u r e t o M a i n t a i n t h e T r a i n A a n d B D i r e c t C u r r e n t E l e c t r i c a l P o w e r S u b s y s t e m s O p e r a b l e J u l y 2 8 , 2 0 1 1 P r a i r i e I s l a n d N u c l e a r G e n e r a t i n g P l a n t P r a i r i e I s l a n d N u c l e a r G e n e r a t i n g P l a n t 2 A g e n d aO p e n i n g R e m a r k s -M a r k S c h i m m e lS e q u e n c e o f E v e n t s -K e v i n D a v i s o nC a u s e s a n d C o r r e c t i v e A c t i o n s -K e v i n D a v i s o nR e g u l a t o r y S i g n i f i c a n c e -J o h n B i c k e lO p e r a t o r A c t i o n s -D a r r e l l L a p c i n s k i C o n c l u s i o n -M a r k S c h i m m e lC l o s i n g R e m a r k s -D e n n i s K o e h l 3 O p e n i n g R e m a r k sX c e l E n e r g y t a k e s i t s o b l i g a t i o n t o p r o t e c t t h e h e a l t h a n d s a f e t y o f t h e p u b l i c v e r y s e r i o u s l yV i o l a t i o nF a i l u r e t o m a i n t a i n t h e T r a i n A a n d B d i r e c t c u r r e n t e l e c t r i c a l p o w e r s u b s y s t e m s o p e r a b l eA g r e e w i t h t h e p e r f o r m a n c e d e f i c i e n c y a n d v i o l a t i o nD i s a g r e e w i t h t h e s i g n i f i c a n c e M o r e t h a n a d e q u a t e t i m e t o d i a g n o s e c h a r g e r l o c k u p 4 S e q u e n c e o f E v e n t s K e v i n D a v i s o n -P l a n t M a n a g e r 5 S e q u e n c e o f E v e n t s 1 9 9 6 1 2 B a t t e r y C h a r g e r l o c k u p d u r i n g I S I 1 9 9 4 / 9 5 B a t t e r y c h a r g e r s i n s t a l l e d 1 9 9 4 1 9 9 7 2 0 0 0 2 0 0 3 2 0 0 6 2 0 0 9 2 0 1 2 1 9 9 7 F o l l o w u p t e s t i n g o f U n i t 1 b a t t e r y c h a r g e r s 1 9 9 9 T e s t p r o c e d u r e r e v i s e d t o r e m o v e 1 2 B a t t e r y C h a r g e r 2 0 0 5 1 2 B a t t e r y C h a r g e r m o d c a n c e l l e d O c t 2 0 1 0 T S 3.8.1.B E n t e r e d f o r D 2 E D G; E x i g e n t T S c h a n g e a p p r o v e d F e b 2 0 1 2 U n i t 2 b a t t e r y c h a r g e r s t o b e r e p l a c e d 1 9 9 9 B a t t e r y c h a r g e r m o d r e q u e s t s 2 0 0 2 I m p r o v e d S t a n d a r d T e c h S p e c i m p l e m e n t e d J u n e 2 0 1 0 S i t e s t a f f e n t e r s 1 2 B a t t e r y C h a r g e r t e s t i n g i s s u e s i n t o C A P M a y 2 0 1 1 U n i t 1 b a t t e r y c h a r g e r s r e p l a c e d 6 C a u s e s a n d C o r r e c t i v e A c t i o nA r o o t c a u s e a n a l y s i s w a s p e r f o r m e d t o i d e n t i f y t h e d i r e c t c a u s e a n d t h e o r g a n i z a t i o n a l a n d p r o g r a m m a t i c b r e a k d o w n s t h a t l e d t o f a i l u r e t o c o r r e c t b a t t e r y c h a r g e r l o c k u p. | | {{#Wiki_filter:Prairie Island Nuclear Generating Plant NRC Region III Regulatory Conference Failure to Maintain the Train A and B Direct Current Electrical Power Subsystems Operable July 28, 2011 |
| 7 C a u s e s a n d C o r r e c t i v e A c t i o n sR o o t C a u s e -D i r e c tT h e o r g a n i z a t i o n h a d d e v e l o p e d a b l i n d s p o t t o t h i s i s s u e. O v e r s e v e r a l y e a r s , m u l t i p l e o p p o r t u n i t i e s s u r f a c e d t o i d e n t i f y a n d c o r r e c t t h e c o n d i t i o n 8 C a u s e s a n d C o r r e c t i v e A c t i o n sR o o t C a u s e -P r o g r a m m a t i cR C-1: E q u i p m e n t i s s u e s b e c o m e l o n g-s t a n d i n g w h e n "C"s e v e r i t y l e v e l C A P s a r e a l l o w e d t o b e c l o s e d t o a s e c o n d a r y w o r k p r o c e s s d e l i v e r a b l e , w h i c h m a y b e c a n c e l e d o r e x t e n d e d b e y o n d t h e o r i g i n a l C A P d u e d a t e.R o o t C a u s e -O r g a n i z a t i o n a lR C-2: B e h a v i o r s n e c e s s a r y t o d r i v e l o n g-s t a n d i n g e q u i p m e n t i s s u e s t o t i m e l y r e s o l u t i o n a r e n e i t h e r m o d e l e d , n o r r e q u i r e d b y P l a n t H e a l t h C o m m i t t e e (P H C).
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| 9 C a u s e s a n d C o r r e c t i v e A c t i o n sC o r r e c t i v e A c t i o n -E q u i p m e n t I m p l e m e n t e d c o m p e n s a t o r y a c t i o n s f o r a l l b a t t e r y c h a r g e r sO b t a i n e d a n E x i g e n t T e c h n i c a l S p e c i f i c a t i o n c h a n g eR e p l a c e d a n d r e t e s t e d U n i t 1 B a t t e r y C h a r g e r s (1 R 2 7)S c h e d u l e d r e p l a c e m e n t o f U n i t 2 B a t t e r y C h a r g e r s (2 R 2 7) P r o c u r e m e n t o f S p a r e a n d U n i t 2 c h a r g e r s i n p r o g r e s s.
| | Agenda Opening Remarks - Mark Schimmel Sequence of Events - Kevin Davison Causes and Corrective Actions - Kevin Davison Regulatory Significance - John Bickel Operator Actions - Darrell Lapcinski Conclusion - Mark Schimmel Closing Remarks - Dennis Koehl 2 |
| 1 0 C a u s e s a n d C o r r e c t i v e A c t i o n sC o r r e c t i v e A c t i o n -P r o c e s s F o r "C"s e v e r i t y l e v e l C A P s , t o e n s u r e a l l o p e n e q u i p m e n t i s s u e s r e m a i n c a p t u r e d i n t h e c o r r e c t i v e a c t i o n p r o c e s s.E s t a b l i s h a P H C C h a r t e r a n d c h a n g e d b e h a v i o r s t h a t i n c o r p o r a t e s t h e k n o w l e d g e g a i n e d f r o m b e n c h m a r k i n g i n d u s t r y l e a d e r s a n d m a k e i t a v a i l a b l e t o S y s t e m a n d P r o g r a m s E n g i n e e r i n g. P H C n e e d s t o b e d e f i n e d a s t h e c h a m p i o n o f p r o j e c t s f o r p r e s e n t a t i o n t o P R G.
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| 1 1 C a u s e s a n d C o r r e c t i v e A c t i o n sC o r r e c t i v e A c t i o n -P r o c e s sI m p l e m e n t a p e r i o d i c P H C r o l l-u p t o e v a l u a t e e f f e c t i v e n e s s o f r e s o l v i n g e q u i p m e n tL e g a c y I s s u e s P l a n 1 2 C o n c l u s i o nS t a t i o n h a d m u l t i p l e o p p o r t u n i t i e s t o i d e n t i f yC o r r e c t i v e a c t i o n s h a v e f o c u s e d o n:R e p l a c e m e n t o f c h a r g e r sC h a n g i n g b e h a v i o r s o f P H C m e m b e r sP r o c e s s c h a n g e s t o a s s u r e s u s t a i n a b i l i t y 1 3 R e g u l a t o r y S i g n i f i c a n c e S c e n a r i o s & R i s k E v a l u a t i o n J o h n B i c k e l -P R A C o n s u l t a n t E n g i n e e r O p e r a t o r A c t i o n s D a r r e l l L a p c i n s k i -S h i f t M a n a g e r 1 4 1 4 R e g u l a t o r y S i g n i f i c a n c e -S c e n a r i o sL O O P e v e n t w i t h E D G D 1 f a i l e d a n d 1 2 B a t t e r y C h a r g e r L o c k u pS c e n a r i o i s m o s t l i m i t i n g t i m e a v a i l a b l e p r i o r t o b a t t e r y d e p l e t i o nP l a n t e m e r g e n c y l i g h t i n g p o w e r e d f r o m t h e 1 2 b a t t e r yM i n i m u m d e s i g n v o l t a g e o n 1 2 b a t t e r y w i l l b e r e a c h e d i n t h r e e h o u r sM o s t r i s k s i g n i f i c a n t s e q u e n c e f r o m t h e P I N G P P R A e v a l u a t i o n s N o t e d b y t h e N R C t o b e s i g n i f i c a n t r i s k c o n t r i b u t o rF a i l u r e o f t h e E D G D 1 w o u l d c a u s e t h e o p e r a t o r s t o p e r f o r m a d d i t i o n a l a c t i o n sL O O P e v e n t w i t h 1 1 a n d 1 2 B a t t e r y C h a r g e r L o c k u p E D G D 1 s u c c e s s f u l l y o p e r a t e sS c e n a r i o i s n o t a s l i m i t i n g i n t i m e a s s c e n a r i o l i s t e d a b o v eP l a n t e m e r g e n c y l i g h t i n g p o w e r e d f r o m t h e A C s o u r c e (E D G D 1 o p e r a t e s).M i n i m u m d e s i g n v o l t a g e o n 1 1 b a t t e r y r e a c h e d i n s i x a n d a h a l f h o u r s.M i n i m u m d e s i g n v o l t a g e o n 1 2 b a t t e r y r e a c h e d i n s e v e n a n d a h a l f h o u r s.
| | Opening Remarks Xcel Energy takes its obligation to protect the health and safety of the public very seriously Violation Failure to maintain the Train A and B direct current electrical power subsystems operable Agree with the performance deficiency and violation Disagree with the significance More than adequate time to diagnose charger lockup 3 |
| 1 5 R e g u l a t o r y S i g n i f i c a n c e -S c e n a r i o s L O O P , E D G D 1 F a i l u r e & 1 2 B a t t e r y C h a r g e r L o c k u p L O O P O c c u r s 1 2 B a t t e r y R e a c h e s M i n i m u m D e s i g n V o l t a g e T=0 T< 1 D G S t a r t S i g n a l T<1 E D G l o a d e d & F a i l e d; C h a r g e r l o c k u p T=1 8 0 T i m e l i n e i n m i n u t e s T<6 0 T i m e f o r O p e r a t o r s t o D i a g n o s e , C r o s s-t i e B u s e s & R e s e t C h a r g e r 1 6 R e g u l a t o r y S i g n i f i c a n c e -S c e n a r i o s L O O P , 1 1 & 1 2 B a t t e r y C h a r g e r L o c k u p L O O P O c c u r s 1 1 B a t t e r y R e a c h e s M i n i m u m D e s i g n V o l t a g e T=0 T< 1 D G S t a r t S i g n a l T<1 E D G l o a d e d; C h a r g e r l o c k u p T=3 9 0 T i m e l i n e i n m i n u t e s T<6 0 T i m e n e e d e d f o r O p e r a t o r s t o D i a g n o s e & R e s e t C h a r g e r T=4 5 0 1 2 B a t t e r y R e a c h e s M i n i m u m D e s i g n V o l t a g e 1 7 O p e r a t o r A c t i o n s -I m m e d i a t eI m m e d i a t e A c t i o n s F o l l o w i n g L O O P E v e n t (m e m o r i z e d a c t i o n s)1 E-0 R e a c t o r T r i p o r S a f e t y I n j e c t i o nS t e p 1: V e r i f y R e a c t o r t r i pS t e p 2: V e r i f y T u r b i n e t r i pS t e p 3: V e r i f y B o t h S a f e g u a r d s B u s e s -E n e r g i z e dL e a d R e a c t o r O p e r a t o r (R O) w i l l r e c o g n i z e t h a t E D G D 1 h a s f a i l e d a n d B u s 1 5 i s d e e n e r g i z e d. R e s p o n s e N o t O b t a i n e d: "I F o n e b u s d e e n e r g i z e d , T H E N i n i t i a t e a c t i o n t o r e s t o r e p o w e r t o d e e n e r g i z e d s a f e g u a r d s b u s p e r 1 C 2 0.5 A O P 1 , R E E N E R G I Z I N G 4.1 6 K V B U S 1 5. S t e p 4: C h e c k i f S I i s A c t u a t e dO p e r a t o r s w i l l t r a n s f e r t o 1 E S-0.1 , R e a c t o r T r i p R e c o v e r yN o S a f e t y i n j e c t i o n 1 8 O p e r a t o r A c t i o n s -T r i p R e c o v e r y T r a n s i t i o n t o 1 E S-0.1 , R e a c t o r T r i p R e c o v e r yC o n t r o l R o o m S u p e r v i s o r (C R S) w i l l r e s t o r e n o r m a l a l a r m r e s p o n s e p r o t o c o l p e r F P-O P-C O O-0 1 "C o n d u c t o f O p e r a t i o n s", A t t a c h m e n t 1 "A l a r m R e s p o n s e".C r e w B r i e f w i l l b e p e r f o r m e d.C R S w i l l d i r e c t t h e R O s t o p e r f o r m a b o a r d w a l k d o w n a n d r e p o r t a n y a l a r m s t h a t a r e u n e x p e c t e d f o r t h e L O O P/r e a c t o r t r i p. O p e r a t o r s a r e t r a i n e d t o l o o k a t e l e c t r i c a l s o u r c e s f o l l o w i n g L O O P e v e n t. P a t t e r n o f a n n u c i a t o r s w i l l a l s o b e e v i d e n t.
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| 1 9 O p e r a t o r A c t i o n s -E m e r g e n c y P l a n S h i f t M a n a g e r A s s u m e s R o l e o f E m e r g e n c y D i r e c t o r W i t h i n 1 5 m i n u t e s , E m e r g e n c y P l a n n i n g c l a s s i f i c a t i o n i s r e q u i r e dT o d e t e r m i n e e s c a l a t i o n c r i t e r i a , S h i f t M a n a g e r w i l l e v a l u a t e a l a r m s o n e l e c t r i c a l p o w e r p a n e lM u l t i p l e p e o p l e t h r o u g h m u l t i p l e p r o c e d u r a l i z e d p a t h s g i v e m a n y o p p o r t u n i t i e s t o d i a g n o s e l o c k u p o f a b a t t e r y c h a r g e r.
| | Sequence of Events Kevin Davison - Plant Manager 4 |
| 2 0 O p e r a t o r A c t i o n s -C o n t r o l R o o m U n i t 2 U n i t 1 2 1 O p e r a t o r A c t i o n s -C o n t r o l R o o m C o n t r o l R o o m f r o m t h e U n i t 1 s i d e. T h e e l e c t r i c a l p o w e r a n n u n c i a t o r p a n e l i s s h o w n b e t w e e n U n i t 1 a n d U n i t 2 C o n t r o l R o o m s w h e r e i t c a n b e e a s i l y s e e n a n d m o n i t o r e d b y b o t h u n i t s o p e r a t o r s.
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| 2 2 O p e r a t o r A c t i o n sA f t e r t h e p l a n t i s s t a b i l i z e d t h e o p e r a t o r s w i l l w a l k t h e p a n e l s. D u r i n g a L O O P , t h e p o w e r p a n e l w i l l b e a p r i o r i t y.T h e d i f f e r e n c e i n t h e p a t t e r n f o r U n i t 1 a n d U n i t 2 A n n u n c i a t o r s w i l l b e q u i c k l y i d e n t i f i e d. O p e r a t o r s a r e t r a i n e d t o i d e n t i f y d i s c r e p a n c i e s t o t h e n o r m.
| | Sequence of Events 1994 / 95 1997 1999 2005 Oct 2010 Feb 2012 Battery Follow up Test 12 Battery TS 3.8.1.B Unit 2 chargers testing of procedure Charger mod Entered for battery installed Unit 1 revised to cancelled D2 EDG; chargers to battery remove 12 Exigent TS be replaced chargers Battery change Charger approved 1994 1997 2000 2003 2006 2009 2012 June 2010 Site staff 1996 2002 enters 12 May 2011 12 Battery 1999 Improved Battery Unit 1 Charger Battery Standard Charger battery lockup charger mod Tech Spec testing issues chargers during ISI requests implemented into CAP replaced 5 |
| 2 3 U n i t 2 G-P a n e l A l a r m s U n i t 1 G-P a n e l A l a r m s 2 4 O p e r a t o r A c t i o n s -R e s t o r e B u s 1 5P e r 1 E-0 , S t e p 3 R N O: I F o n e b u s d e e n e r g i z e d , T H E N i n i t i a t e a c t i o n t o r e s t o r e p o w e r t o d e e n e r g i z e d s a f e g u a r d s b u s p e r 1 C 2 0.5 A O P 1 , R E E N E R G I Z I N G 4.1 6 K V B U S 1 5. U n i t 1 S S w i l l i n s t r u c t U n i t 1 L e a d R O t o e n t e r 1 C 2 0.5 A O P 1 p e r 1 E-0. D i s p a t c h o u t p l a n t o p e r a t o r t o l o c a l l y c h e c k E D G D 1.P e r 1 C 2 0.5 A O P 1 , i t w o u l d b e d e t e r m i n e d t h a t n o l o c k o u t e x i s t s o n B u s 1 5 a n d i s a v a i l a b l e f o r r e p o w e r i n gD u e t o L O O P e v e n t a n d D 1 E D G f a i l u r e , B u s 1 5 w i l l b e r e e n e r g i z e d v i a b u s-t i e b r e a k e r s p e r 1 C 2 0.5 A O P 4.
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| 2 5 O p e r a t o r A c t i o n s -C h a r g e r R e s t a r tC u e s A v a i l a b l e T o O p e r a t o r1 2 D C S y s t e m T r o u b l e A l a r m (4 7 0 2 4-1 1 0 5)1 2 D C P a n e l U n d e r v o l t a g e A l a r m (4 7 0 2 4-1 2 0 4)A l a r m R e s p o n s e P r o c e d u r e s (A R P) w i l l i n s t r u c t o p e r a t o r t o r e v i e w b a t t e r y d a t a i n d i c a t i o n o n t h e E m e r g e n c y R e s p o n s e C o m p u t e r S y s t e m (E R C S).
| | Causes and Corrective Action A root cause analysis was performed to identify the direct cause and the organizational and programmatic breakdowns that led to failure to correct battery charger lockup. |
| 2 6 O p e r a t o r A c t i o n s -C h a r g e r R e s t a r t O p e r a t o r s a r e t r a i n e d t o u s e a l l a v a i l a b l e i n d i c a t i o n. T h e E m e r g e n c y R e s p o n s e C o m p u t e r S y s t e m (E R C S) w i l l b e i n i t i a t e d t o d e t e r m i n e s t a t u s o f t h e b a t t e r i e s. T h i s s c r e e n i s a v a i l a b l e o n t h e p o w e r p a n e l a n d w o u l d c o n t i n u e t o h a v e p o w e r d u r i n g a L O O P.
| | 6 |
| 2 7 2 8 2 9 3 0 3 1 3 1 3 2 O p e r a t o r A c t i o n s -C h a r g e r R e s t a r tP r o c e d u r e I n s t r u c t i o n t o R e s t a r t B a t t e r y C h a r g e rA R P w i l l a l s o r e f e r o p e r a t o r t o 1 C 2 0.9 A O P 4: F a i l u r e o f 1 2 B a t t e r y C h a r g e r.1 C 2 0.9 A O P 4 (A t t a c h m e n t B) -R e v 1 0 , p r o v i d e s i n s t r u c t i o n t o r e s t a r t b a t t e r y c h a r g e r.O u t p l a n t o p e r a t o r r e q u i r e d.O u t p l a n t O p e r a t o r s A v a i l a b l e t o R e s p o n dT w o T u r b i n e B u i l d i n g (T B) O p e r a t o r s p e r U n i t (4 t o t a l).T w o o f t h e o p e r a t o r s (o n e p e r u n i t) p e r f o r m i m m e d i a t e a c t i o n s o f 1 E S-0.1 , A t t a c h m e n t J.T w o T B O p e r a t o r s a v a i l a b l e t o r e s p o n d t o E D G D 1 f a i l u r e a n d 1 2 B a t t e r y C h a r g e r.I n a d d i t i o n , a l t h o u g h n o t c r e d i t e d i n t h e P R A a n a l y s i s , A u x i l i a r y B u i l d i n g (A B) o p e r a t o r (2 t o t a l) c a n b e a v a i l a b l e t o r e s p o n d t o T B i s s u e s s i n c e t h i s s c e n a r i o w o u l d n o t r e q u i r e o u t p l a n t a c t i o n s i n t h e A B.
| | |
| 3 3 O p e r a t o r A c t i o n s -C h a r g e r R e s t a r tC o m p l e x i t y o f T a s k a n d T i m e T o C o m p l e t e A c t i o nS i m p l e a c t i o n , o p e n a n d c l o s e A C I n p u t B r e a k e r o n f r o n t p a n e l.B o t h t h e c o n t r o l r o o m a n d o u t p l a n t a c t i o n t i m e s w e r e c o n f i r m e d d u r i n g t w o s i m u l a t o r c a s e s t u d i e s.A p p r o x i m a t e t i m e t o c o m p l e t e B u s 1 5 r e p o w e r a n d r e s t a r t o f 1 2 b a t t e r y c h a r g e r a c t i o n s b a s e d o n t w o s i m u l a t o r c a s e s t u d i e s: l e s s t h a n 6 0 m i n u t e s 3 4 O p e r a t o r A c t i o n s T h e o n l y m a n u a l a c t i o n r e q u i r e d t o p h y s i c a l l y r e s e t t h e b a t t e r y c h a r g e r i s t o s w i t c h t h e A C I n p u t b r e a k e r s h o w n a b o v e o n t h e l e f t f r o m t h e O f f t o t h e O n p o s i t i o n.
| | Causes and Corrective Actions Root Cause - Direct The organization had developed a blind spot to this issue. |
| 3 5 O p e r a t o r A c t i o n s -C o n c l u s i o n B a t t e r y C h a r g e r R e s e t1 E S-0.1 T r i p R e c o v e r y O p e r a t o r C u e s 1 2 D C T r o u b l e A l a r m 1 2 D C P a n e l U V A l a r m C o m p u t e r a l a r m s / i n d i c a t i o n s E A L E s c a l a t i o n C r i t e r i a P r o c e d u r e s A R P & A O P F a i l u r e o f 1 2 B a t t e r y C h a r g e r R e s p o n s e S i m p l e A c t i o n D i r e c t e d b y P r o c e d u r e L O O P w/ D 1 F a i l u r e 1 E-0 T r i p a n d S I A O P t o R e s t o r e B u s 1 5 B u s 1 5 R e s t o r e d T-0 T-6 0 3 6 3 6 R i s k E v a l u a t i o nK e y R i s k S i g n i f i c a n c e Q u e s t i o n:"D o o p e r a t o r s h a v e e n o u g h t i m e t o d e t e c t a n d r e s e t t r i p p e d b a t t e r y c h a r g e r , b e f o r e b a t t e r i e s b e c o m e u n a v a i l a b l e ?"X c e l H E P a n a l y s i s: H E P=8.9 E-4 (E P R I H R A C a l c.)N R C a n a l y s i s: H E P=2.2 E-2 (S P A R-H) 3 7 3 7 R i s k E v a l u a t i o nR A S P M a n u a l V o l.3 S e c t i o n 2.3 r e q u i r e s:"T e c h n i c a l r e v i e w s. C h e c k w h e t h e r a k n o w l e d g e a b l e s p e c i a l i s t r e v i e w e d t h e r e a s o n a b l e n e s s a n d a c c e p t a b i l i t y o f t h e r e s u l t s o f t h e t h e r m a l h y d r a u l i c , s t r u c t u r a l , o r o t h e r s u p p o r t i n g e n g i n e e r i n g b a s e s t h a t w e r e u s e d t o j u s t i f y t h e s u c c e s s c r i t e r i a. (S C-B 5)"F i d e l i t y t o a s-b u i l t d e s i g n:F o r C C F o f B a t t e r y C h a r g e r s s c e n a r i o w i t h b o t h d i e s e l s r u n n i n g (n o e m e r g e n c y l i g h t i n g l o a d s o n b a t t e r y) -7.5 h r 7.5 h r b a t t e r y c a p a c i t y b a t t e r y c a p a c i t yF o r D 1 d i e s e l f a i l u r e a n d 1 2 C h a r g e r t r i p -3 h r b a t t e r y 3 h r b a t t e r y c a p a c i t y c a p a c i t y 3 8 R i s k E v a l u a t i o nR A S P M a n u a l V o l. 1 , S e c t i o n 6.3.1 r e q u i r e s c o n s i d e r i n g f o l l o w i n g i n t h e r e c o v e r y a n a l y s i s:"D e m o n s t r a t i o n t h a t t h e a c t i o n i s p l a u s i b l e a n d f e a s i b l e f o r t h e s c e n a r i o s t o w h i c h r e c o v e r y/r e p a i r a c t i o n a r e a p p l i e d (H L R-H R-H).""A v a i l a b i l i t y o f p r o c e d u r e s , o p e r a t o r t r a i n i n g , c u e s , a n d m a n p o w e r (H R-H 2).""R e l e v a n t s c e n a r i o-s p e c i f i c p e r f o r m a n c e s h a p i n g f a c t o r s i n t h e H R A (H R-H 2 a n d H R-G 3)."3 8 3 9 3 9 R i s k E v a l u a t i o n 4 0 4 0 R i s k E v a l u a t i o nT o o b t a i n H E P=2.2 E-2 , N R C S P A R-H t r e a t m e n t o m i t s c o n s i d e r a t i o n o f a v a i l a b l e t i m eW i t h c o m m o n c a u s e c h a r g e r f a i l u r e a n d D 1/D 2 o p e r a b l e: 7.5 h r s a v a i l a b l e f o r r e c o v e r yW i t h D 1 f a i l i n g a n d l i g h t i n g t r a n s f e r r e d t o b a t t e r y: 3 h r s a v a i l a b l e f o r r e c o v e r yP e r t h e S P A R-H m o d e l: 1 h r t o d e t e c t/r e s e t 3 h r b a t t e r i e s (e x p a n s i v e t i m e)1.5 h r t o d e t e c t/r e s e t 3 h r b a t t e r i e s (e x p a n s i v e t i m e)1.5 h r t o d e t e c t r e s e t 2.5 h r b a t t e r i e s (e x t r a t i m e) 4 1 4 1 R i s k E v a l u a t i o n 4 2 4 2 R i s k E v a l u a t i o nP e e r R e v i e w o f S P A R-H m o d e lP a g e I-1 7 o f N U R E G/C R-6 8 8 3 s t a t e s:"W e d o r e d u c e t h e H E P f o r "a t-p o w e r"s i t u a t i o n s w h e r e t h e r e i s e x t r a o r e x p a n s i v e t i m e a v a i l a b l e , b e y o n d a c e r t a i n t i m e m i n i m u m c o r r e s p o n d i n g t o i n t e r p r e t a t i o n o f t h e T H E R P d i a g n o s i s c u r v e s."
| | Over several years, multiple opportunities surfaced to identify and correct the condition 7 |
| 4 3 4 3 R i s k E v a l u a t i o n I n c o n c l u s i o n , i f N R C w e r e t o c o n s i d e r:"A s-b u i l t , A s-o p e r a t e d"b a t t e r y c a p a c i t y T i m e a v a i l a b l e f o r r e s e t t i n g t r i p p e d c h a r g e r f o r t h e d o m i n a n t s e q u e n c e s o f i n t e r e s tP e r S P A R-H p r o c e s s t h e r e i s E x t r a/E x p a n s i v e t i m e R i s k s i g n i f i c a n c e i s G R E E N.
| | |
| 4 4 4 4 C o n c l u s i o n M a r k S c h i m m e l -S i t e V i c e P r e s i d e n t 4 5 4 5 C l o s i n g R e m a r k s D e n n i s K o e h l -C h i e f N u c l e a r O f f i c e r 4 6}}
| | Causes and Corrective Actions Root Cause - Programmatic RC-1: Equipment issues become long-standing when C severity level CAPs are allowed to be closed to a secondary work process deliverable, which may be canceled or extended beyond the original CAP due date. |
| | Root Cause - Organizational RC-2: Behaviors necessary to drive long-standing equipment issues to timely resolution are neither modeled, nor required by Plant Health Committee (PHC). |
| | 8 |
| | |
| | Causes and Corrective Actions Corrective Action - Equipment Implemented compensatory actions for all battery chargers Obtained an Exigent Technical Specification change Replaced and retested Unit 1 Battery Chargers (1R27) |
| | Scheduled replacement of Unit 2 Battery Chargers (2R27) |
| | Procurement of Spare and Unit 2 chargers in progress. |
| | 9 |
| | |
| | Causes and Corrective Actions Corrective Action - Process For C severity level CAPs, to ensure all open equipment issues remain captured in the corrective action process. |
| | Establish a PHC Charter and changed behaviors that incorporates the knowledge gained from benchmarking industry leaders and make it available to System and Programs Engineering. |
| | PHC needs to be defined as the champion of projects for presentation to PRG. |
| | 10 |
| | |
| | Causes and Corrective Actions Corrective Action - Process Implement a periodic PHC roll-up to evaluate effectiveness of resolving equipment Legacy Issues Plan 11 |
| | |
| | Conclusion Station had multiple opportunities to identify Corrective actions have focused on: |
| | Replacement of chargers Changing behaviors of PHC members Process changes to assure sustainability 12 |
| | |
| | Regulatory Significance Scenarios & Risk Evaluation John Bickel - PRA Consultant Engineer Operator Actions Darrell Lapcinski - Shift Manager 13 |
| | |
| | Regulatory Significance - Scenarios LOOP event with EDG D1 failed and 12 Battery Charger Lockup Scenario is most limiting time available prior to battery depletion Plant emergency lighting powered from the 12 battery Minimum design voltage on 12 battery will be reached in three hours Most risk significant sequence from the PINGP PRA evaluations Noted by the NRC to be significant risk contributor Failure of the EDG D1 would cause the operators to perform additional actions LOOP event with 11 and 12 Battery Charger Lockup EDG D1 successfully operates Scenario is not as limiting in time as scenario listed above Plant emergency lighting powered from the AC source (EDG D1 operates). |
| | Minimum design voltage on 11 battery reached in six and a half hours. |
| | Minimum design voltage on 12 battery reached in seven and a half hours. |
| | 14 |
| | |
| | Regulatory Significance - Scenarios LOOP, EDG D1 Failure & 12 Battery Charger Lockup T< 1 T=180 T=0 T<1 T<60 Time for Operators to Diagnose, Cross-tie Buses & Reset Charger LOOP Occurs DG Start Signal 12 Battery Reaches EDG Minimum Design loaded & Voltage Failed; Charger Timeline in minutes lockup 15 |
| | |
| | Regulatory Significance - Scenarios LOOP, 11 & 12 Battery Charger Lockup T< 1 T=390 T=450 T=0 T<1 T<60 Time needed for Operators to Diagnose |
| | & Reset Charger LOOP Occurs DG Start Signal 11 Battery 12 Battery EDG Reaches Reaches loaded; Minimum Minimum Charger Design Design lockup Timeline in minutes Voltage Voltage 16 |
| | |
| | Operator Actions - Immediate Immediate Actions Following LOOP Event (memorized actions) 1E-0 Reactor Trip or Safety Injection Step 1: Verify Reactor trip Step 2: Verify Turbine trip Step 3: Verify Both Safeguards Buses - Energized Lead Reactor Operator (RO) will recognize that EDG D1 has failed and Bus 15 is deenergized. |
| | Response Not Obtained: IF one bus deenergized, THEN initiate action to restore power to deenergized safeguards bus per 1C20.5 AOP1, REENERGIZING 4.16KV BUS 15. |
| | Step 4: Check if SI is Actuated Operators will transfer to 1ES-0.1, Reactor Trip Recovery No Safety injection 17 |
| | |
| | Operator Actions - Trip Recovery Transition to 1ES-0.1, Reactor Trip Recovery Control Room Supervisor (CRS) will restore normal alarm response protocol per FP-OP-COO-01 Conduct of Operations, Attachment 1 Alarm Response. |
| | Crew Brief will be performed. |
| | CRS will direct the ROs to perform a board walkdown and report any alarms that are unexpected for the LOOP/reactor trip. |
| | Operators are trained to look at electrical sources following LOOP event. Pattern of annuciators will also be evident. |
| | 18 |
| | |
| | Operator Actions - Emergency Plan Shift Manager Assumes Role of Emergency Director Within 15 minutes, Emergency Planning classification is required To determine escalation criteria, Shift Manager will evaluate alarms on electrical power panel Multiple people through multiple proceduralized paths give many opportunities to diagnose lockup of a battery charger. |
| | 19 |
| | |
| | Operator Actions - Control Room Unit 2 Unit 1 20 |
| | |
| | Operator Actions - Control Room Control Room from the Unit 1 side. The electrical power annunciator 21 panel is shown between Unit 1 and Unit 2 Control Rooms where it can be easily seen and monitored by both units operators. |
| | |
| | Operator Actions After the plant is stabilized the operators will walk the panels. |
| | During a LOOP, the power panel will be a priority. |
| | The difference in the pattern for Unit 1 and Unit 2 Annunciators will be quickly identified. |
| | Operators are trained to identify discrepancies to the norm. |
| | 22 |
| | |
| | Unit 2 G-Panel Alarms Unit 1 G-Panel Alarms 23 |
| | |
| | Operator Actions - Restore Bus 15 Per 1E-0, Step 3 RNO: |
| | IF one bus deenergized,THEN initiate action to restore power to deenergized safeguards bus per 1C20.5 AOP1, REENERGIZING 4.16KV BUS 15. |
| | Unit 1 SS will instruct Unit 1 Lead RO to enter 1C20.5 AOP1 per 1E-0. |
| | Dispatch outplant operator to locally check EDG D1. |
| | Per 1C20.5 AOP1, it would be determined that no lockout exists on Bus 15 and is available for repowering Due to LOOP event and D1 EDG failure, Bus 15 will be reenergized via bus-tie breakers per 1C20.5 AOP4. |
| | 24 |
| | |
| | Operator Actions - Charger Restart Cues Available To Operator 12 DC System Trouble Alarm (47024-1105) 12 DC Panel Undervoltage Alarm (47024-1204) |
| | Alarm Response Procedures (ARP) will instruct operator to review battery data indication on the Emergency Response Computer System (ERCS). |
| | 25 |
| | |
| | Operator Actions - Charger Restart Operators are trained to use all available indication. The Emergency Response Computer System (ERCS) will be initiated to determine 26 status of the batteries. This screen is available on the power panel and would continue to have power during a LOOP. |
| | |
| | 27 28 29 30 31 Operator Actions - Charger Restart Procedure Instruction to Restart Battery Charger ARP will also refer operator to 1C20.9 AOP4: Failure of 12 Battery Charger. |
| | 1C20.9 AOP4 (Attachment B) - Rev 10, provides instruction to restart battery charger. |
| | Outplant operator required. |
| | Outplant Operators Available to Respond Two Turbine Building (TB) Operators per Unit (4 total). |
| | Two of the operators (one per unit) perform immediate actions of 1ES-0.1, Attachment J. |
| | Two TB Operators available to respond to EDG D1 failure and 12 Battery Charger. |
| | In addition, although not credited in the PRA analysis, Auxiliary Building (AB) operator (2 total) can be available to respond to TB issues since this scenario would not require outplant actions in the AB. |
| | 32 |
| | |
| | Operator Actions - Charger Restart Complexity of Task and Time To Complete Action Simple action, open and close AC Input Breaker on front panel. |
| | Both the control room and outplant action times were confirmed during two simulator case studies. |
| | Approximate time to complete Bus 15 repower and restart of 12 battery charger actions based on two simulator case studies: less than 60 minutes 33 |
| | |
| | Operator Actions The only manual action required to physically reset the battery charger is to switch the AC Input breaker shown above on the left from the Off to the On position. 34 |
| | |
| | Operator Actions - Conclusion T-0 LOOP w/ D1 Failure AOP to Restore 1E-0 Trip and SI Bus 15 Bus 15 Restored 1ES-0.1 Trip Recovery 12 DC Trouble Alarm 12 DC Panel UV Alarm Operator Cues Computer alarms / indications EAL Escalation Criteria ARP & AOP Failure of 12 Procedures Battery Charger Simple Action Response Directed by Procedure Battery Charger Reset T-60 35 |
| | |
| | Risk Evaluation Key Risk Significance Question: |
| | Do operators have enough time to detect and reset tripped battery charger, before batteries become unavailable ? |
| | Xcel HEP analysis: HEP=8.9E-4 (EPRI HRA Calc.) |
| | NRC analysis: HEP=2.2E-2 (SPAR-H) 36 |
| | |
| | Risk Evaluation RASP Manual Vol.3 Section 2.3 requires: |
| | Technical reviews. Check whether a knowledgeable specialist reviewed the reasonableness and acceptability of the results of the thermal hydraulic, structural, or other supporting engineering bases that were used to justify the success criteria. (SC-B5) |
| | Fidelity to as-built design: |
| | For CCF of Battery Chargers scenario with both diesels running (no emergency lighting loads on battery) - 7.5hr battery capacity For D1 diesel failure and 12 Charger trip - 3hr battery capacity 37 |
| | |
| | Risk Evaluation RASP Manual Vol. 1, Section 6.3.1 requires considering following in the recovery analysis: |
| | Demonstration that the action is plausible and feasible for the scenarios to which recovery/repair action are applied (HLR-HR-H). |
| | Availability of procedures, operator training, cues, and manpower (HR-H2). |
| | Relevant scenario-specific performance shaping factors in the HRA (HR-H2 and HR-G3). |
| | 38 |
| | |
| | Risk Evaluation 39 |
| | |
| | Risk Evaluation To obtain HEP=2.2E-2, NRC SPAR-H treatment omits consideration of available time With common cause charger failure and D1/D2 operable: 7.5 hrs available for recovery With D1 failing and lighting transferred to battery: 3 hrs available for recovery Per the SPAR-H model: |
| | 1hr to detect/reset 3hr batteries (expansive time) 1.5hr to detect/reset 3hr batteries (expansive time) 1.5hr to detect reset 2.5hr batteries (extra time) 40 |
| | |
| | Risk Evaluation 41 |
| | |
| | Risk Evaluation Peer Review of SPAR-H model Page I-17 of NUREG/CR-6883states: |
| | We do reduce the HEP for at-power situations where there is extra or expansive time available, beyond a certain time minimum corresponding to interpretation of the THERP diagnosis curves. |
| | 42 |
| | |
| | Risk Evaluation In conclusion, if NRC were to consider: |
| | As-built, As-operated battery capacity Time available for resetting tripped charger for the dominant sequences of interest Per SPAR-H process there is Extra/Expansive time Risk significance is GREEN. |
| | 43 |
| | |
| | Conclusion Mark Schimmel - Site Vice President 44 |
| | |
| | Closing Remarks Dennis Koehl - Chief Nuclear Officer 45 |
| | |
| | 46}} |
|
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Category:Meeting Agenda
MONTHYEARPMNS20240269, Notice of Meeting with Northern States Power Company - Minnesota, Doing Business as Xcel Energy2024-02-26026 February 2024 Notice of Meeting with Northern States Power Company - Minnesota, Doing Business as Xcel Energy ML24029A0382024-01-31031 January 2024 January 31, 2024, Pre-application Meeting Presentation - Prairie Island ISFSI License Amendment Request to Add Grace to License Conditions ML24008A0132024-01-0808 January 2024 Notice of Public Meeting with Xcel Energy to Discuss the Prairie Island ISFSI Amendment ML23159A2542023-06-0808 June 2023 Pre-application Meeting with Xcel Energy to Discuss the Amendment Application for the Prairie Island ISFSI PMNS20230663, Notice of Meeting with Northern States Power Company, Doing Business as Xcel Energy2023-06-0202 June 2023 Notice of Meeting with Northern States Power Company, Doing Business as Xcel Energy ML23102A1752023-04-14014 April 2023 April 14, 2023 TS 3.7.8 LAR Pre-Submittal Meeting Slides PMNS20230262, Notice of Meeting with Northern States Power Company, Doing Business as Xcel Energy2023-04-12012 April 2023 Notice of Meeting with Northern States Power Company, Doing Business as Xcel Energy PMNS20220096, Pre-Application Meeting with Xcel Energy to Discuss Pressure-Temperature Limit Report Amendment for Prairie Island Nuclear Generating Plant, Units 1 and 2 (Prairie Island)2022-02-0707 February 2022 Pre-Application Meeting with Xcel Energy to Discuss Pressure-Temperature Limit Report Amendment for Prairie Island Nuclear Generating Plant, Units 1 and 2 (Prairie Island) PMNS20211339, Meeting with Northern States Power Company Regarding Prairie Island Nuclear Generating Plant, Units 1 and 2, License Amendment Request Related to the Cooling Water System2021-10-15015 October 2021 Meeting with Northern States Power Company Regarding Prairie Island Nuclear Generating Plant, Units 1 and 2, License Amendment Request Related to the Cooling Water System ML21221A0202021-08-11011 August 2021 Nis Pr Bypass Test Panel License Amendment Request PMNS20210949, Meeting with Northern States Power Company Regarding Prairie Island Nuclear Generating Plant, Units 1 and 2, Proposed License Amendment Request2021-07-21021 July 2021 Meeting with Northern States Power Company Regarding Prairie Island Nuclear Generating Plant, Units 1 and 2, Proposed License Amendment Request PMNS20210528, Meeting with Northern States Power Company Regarding Prairie Island Nuclear Generating Plant, Units 1 and 2, Proposed License Amendment Request2021-05-0505 May 2021 Meeting with Northern States Power Company Regarding Prairie Island Nuclear Generating Plant, Units 1 and 2, Proposed License Amendment Request ML21022A0082021-01-22022 January 2021 Teleconference with Xcel Energy to Discuss a Planned License Amendment Request for Monticello Nuclear Generating Plant (Monticello) and Prairie Island Nuclear Generating Plant, Units 1 and 2 (Prairie Island) ML20280A6092020-10-0606 October 2020 Teleconference to Discuss the Prairie Island Nuclear Generating Plant, Units 1 and 2, (Prairie Island) License Amendment Request to Adopt TSTF-505 Provide Risk-Informed Extended Completion Times RITSTF Initiative 4b ML19347B0722019-12-12012 December 2019 TVA and Xcel Energy Slides for Joint Presubmittal Meeting to License Amendment Requests to Adopt WCAP-17661, Revision 1 ML19268A0422019-09-26026 September 2019 Pre-Application Meeting License Amendment Request Revise Technical Specifications to Adopt Risk Informed Completion Times TSTF-505, Revision 2, Provide Risk-Informed Extended Completion Times - RITSTF Initiative 4b ML19070A2412019-03-11011 March 2019 Notice of Meeting with Xcel Energy to Discuss a Seismic Considerations for a Proposed License Amendment Increasing the Amount of Special Nuclear Material Authorized for Storage at the Prairie Island ISFSI ML19074A1312019-03-11011 March 2019 Revised Notice of Meeting with Xcel Energy to Discuss a Seismic Considerations for a Proposed License Amendment Increasing the Amount of Special Nuclear Material Authorized for Storage at the Prairie Island ISFSI ML19045A6682019-02-14014 February 2019 Notice of Meeting with Xcel Energy to Discuss a Proposed License Amendment Increasing the Amount of Special Nuclear Material Authorized for Storage at the Prairie Island Independent Spent Fuel Storage Installation ML15183A3992015-07-0101 July 2015 Ltr. 07/01/15 Point Beach U.S. Nuclear Regulatory Commission Region III 2015 Operator Licensing Workshop (Public Meeting) (Drm) ML15183A3862015-07-0101 July 2015 Ltr. 07/01/15 Prairie Island U.S. Nuclear Regulatory Commission Region III 2015 Operator Licensing Workshop (Public Meeting) (Drm) ML15183A4842015-07-0101 July 2015 Ltr. 07/01/15 Davis-Besse U.S. Nuclear Regulatory Commission Region III 2015 Operator Licensing Workshop (Public Meeting) (Drm) ML15183A4792015-07-0101 July 2015 Ltr. 07/01/15 D.C. Cook U.S. Nuclear Regulatory Commission Region III 2015 Operator Licensing Workshop (Public Meeting)(Drm) ML15183A4782015-07-0101 July 2015 Ltr. 07/01/15 Duane Arnold U.S. Nuclear Regulatory Commission Region III 2015 Operator Licensing Workshop (Public Meeting) (Drm) ML15183A4722015-07-0101 July 2015 Ltr. 07/01/2015 Fermi U.S. Nuclear Regulatory Commission Region III 2015 Operator Licensing Workshop (Public Meeting) (Drm) ML15183A4632015-07-0101 July 2015 Ltr. 07/01/15 Monticello U.S. Nuclear Regulatory Commission Region III 2015 Operator Licensing Workshop (Public Meeting) (Drm) ML15183A4452015-07-0101 July 2015 Ltr. 07/01/15 Perry U.S. Nuclear Regulatory Commission Region III 2015 Operator Licensing Workshop (Public Meeting) (Drm) ML15182A4412015-07-0101 July 2015 Notice and Agenda - 2015 Operator Licensing Workshop ML15114A0432015-04-23023 April 2015 PI 2014 PIR and EOC Meeting Notice ML14169A5862014-06-13013 June 2014 Operator License Workshop Invitation ML13056A0262013-02-25025 February 2013 Regulatory Conference Slide Presentation ML12326A9702012-11-21021 November 2012 Summary of October 24, 2012, Meeting with the Northern States Power Company, D/B/A Excel Energy Regarding Security Requirements and Changes Pertaining to Prairie Island TAC L24689 W/ Encl 1 (Attendees) and Encl 2 (Agenda) ML12318A0572012-11-13013 November 2012 12/6/2012 - Rescheduled Notice of Meeting with Xcel Energy Concerning Prairie Island Nuclear Generating Plant, Units 1 and 2 ML12306A3222012-11-0101 November 2012 Notice of Forthcoming Meeting with Xcel Energy Concerning Prairie Island Nuclear Generating Plant, Units 1 and 2 ML12249A2702012-09-11011 September 2012 Notice of Forthcoming Pre-Application Meeting with Xcel Energy, Inc. Concerning Prairie Island Nuclear Generating Plant ML12138A3312012-05-17017 May 2012 05/31/2012, Notice of Significant Licensee Meeting (non-public) Regarding Operator Licensing Workshop and Meeting ML1208703892012-03-30030 March 2012 Notice of Pre-Application Meeting with Xcel Energy Concerning Prairie Island Nuclear Generating Plant, Units 1 and 2, to Discuss Licensee'S Proposed NFPA 805, Performance Based Standard for Fire Protection for Light Weight Reactor ... ML1122803892011-08-18018 August 2011 Pre-Application Meeting for Prairie Island Nuclear Generating Plant (Ping) Extended Power Uprate (EPU) ML1121505252011-08-0404 August 2011 Notice of Forthcoming Pre-Application Meeting with Licensee for Prairie Island Nuclear Generating Plant, Units 1 and 2 to Discuss Extended Power Uprate License Amendment Request ML1119903462011-07-28028 July 2011 Meeting Presentation, Prairie Island Nuclear Generating Plant - Failure to Maintain the Train a and B Direct Current Electrical Power Subsystems Operable ML1113703982011-05-20020 May 2011 Notice of Forthcoming Pre-Application Meeting with Licensee for Prairie Island Nuclear Generation Plant, Units 1 and 2, to Discuss Proposed Technical Specification and Licensing Basis Changes to Diesel Fuel Oil System ML1104702792011-02-16016 February 2011 Notice of Forthcoming Meeting with Licensee for Prairie Island Nuclear Generating Plant, Unit 1 to Discuss License Amendment Request to Revise Surveillance Requirement Footnote in Technical Specification 3.8.1, AC Sources - Operating. ML1100502702011-01-0505 January 2011 Notice of Closed Pre-Application Meeting NSPM Staff to Discuss Proposed Physical Security Plan Changes That Will Be Submitted for NRC Review and Approval Via License Amendment Request ML1032603272010-11-24024 November 2010 Notice of Pre-Application Meeting with Licensee for Prairie Island Nuclear Generating Plant, Units 1 and 2 to Discuss Spent Fuel Pool Criticality and Extended Power Uprate ML1023805712010-08-25025 August 2010 Meeting Presentation Alternative Source Term Steam Generator Tube Rupture Margin to Overfill Evaluation - Prairie Island Nuclear Generating Plant ML1022200872010-08-10010 August 2010 Forthcoming Meeting with Northern States Power Company - Minnesota (Nspm), to Discuss the Prairie Island Nuclear Generating Plant Steam Generator Margin-to-Overfill Analysis as It Relates to Pingp'S License Amendment Request to Adopt... ML1009707112010-04-0808 April 2010 Revised Notice of Pre-Application Meeting with Licensee for Prairie Island Nuclear Generating Plant, Units 1 and 2 to Discuss Extended Power Uprate License Amendment Request ML1008205732010-03-26026 March 2010 Notice of Forthcoming Pre-Application Meeting with Licensee for Prairie Island Nuclear Generating Plant, Units 1 and 2 to Discuss Extended Power Uprate License Amendment Request ML0932901282009-12-0101 December 2009 Licensee Slides for Public Meeting ML0933102842009-12-0101 December 2009 Notice of Meeting with Prairie Island to Address Substantive Cross-Cutting Issues in the Area of Human Performance - Slides 2024-02-26
[Table view] Category:Meeting Briefing Package/Handouts
MONTHYEARML24127A2402024-05-0707 May 2024 Presentation Slides for Prairie Island 2023 End-of-Cycle Meeting ML24029A0382024-01-31031 January 2024 January 31, 2024, Pre-application Meeting Presentation - Prairie Island ISFSI License Amendment Request to Add Grace to License Conditions ML23168A0032023-06-20020 June 2023 Handout for 6/23/2023 Pre-Application Public Meeting with Prairie Island Nuclear Generating Plant to Revise ISFSI TS 4.4 for TN-40HT Casks ML23156A2602023-06-0505 June 2023 2022 Prairie Island End-of-Cycle Meeting Presentation ML23102A1752023-04-14014 April 2023 April 14, 2023 TS 3.7.8 LAR Pre-Submittal Meeting Slides ML22130A5852022-05-10010 May 2022 2021 Monticello and Prairie Island Nuclear Generating Plant End-of-Cycle Meeting Presentation ML22048B1812022-02-18018 February 2022 Pre-Application Meeting for Prairie Island TS 5.6.6, PTLR, LAR ML21221A0202021-08-11011 August 2021 Nis Pr Bypass Test Panel License Amendment Request ML21166A3792021-06-15015 June 2021 Units 1 and 2 2020 End-of-Cycle Meeting Presentation ML21032A2632021-02-0303 February 2021 Slides for Public Meeting with Xcel Energy to Discuss a Planned Amendment to Combine the Emergency Plans and Create a Common Emergency Offsite Facility for Monticello and Prairie Island ML19347B0722019-12-12012 December 2019 TVA and Xcel Energy Slides for Joint Presubmittal Meeting to License Amendment Requests to Adopt WCAP-17661, Revision 1 ML19268A0422019-09-26026 September 2019 Pre-Application Meeting License Amendment Request Revise Technical Specifications to Adopt Risk Informed Completion Times TSTF-505, Revision 2, Provide Risk-Informed Extended Completion Times - RITSTF Initiative 4b ML19210D4512019-07-22022 July 2019 Abeyance Seal Preapplication Meeting Slides ML18051A1752018-02-20020 February 2018 Pre-Application Meeting License Amendment for TSTF-425 Relocation of Specific Surveillance Frequency Requirements to a Licensee Controlled Program Xcel Energy 2/20/2018 ML17240A3382017-08-30030 August 2017 Non-Safety Related Digital Feedwater and Amsac/Dss Control Systems Replacement Project Presentation ML17198A2632017-07-17017 July 2017 Pre-Application Meeting ML17066A3732017-03-0909 March 2017 Spent Fuel Pool Criticality Technical Specification Changes Round 2 Request for Additional Information Public Meeting: March 9, 2017 ML17037D1172017-02-0707 February 2017 License Amendment Requests for Change in Emergency Plan Staff Augmentation Response Times Pre-Submittal Meeting for Prairie Island Nuclear Generating Plant Monticello Nuclear Generating Plant: February 7, 2017 ML17023A0652017-01-24024 January 2017 Pre-Submittal Call Regarding License Amendment Requests for Prairie Island Nuclear Generating Plant, Units 1 and 2 and Monticello Nuclear Generating Plant Emergency Action Level Scheme Changes ML15140A3342015-05-13013 May 2015 Public Meeting 05132015 Licensee Slides Only ML15105A0372015-04-14014 April 2015 Xcel Energy Slide Presentation to Support Pre-Application Meeting on April 14, 2015, to Discuss Nuclear Fuel Design Transition to Include Integral Fuel Burnable Absorber (Ifba) at the Prairie Island Nuclear Generating Plant ML14323B0222014-11-19019 November 2014 Regcon, November 19-20, 2014: 03-Info-Session-2 Ronald Johnson - Tribal Perspective on Continued Storage ML14153A0242014-05-16016 May 2014 Xcel Energy'S Presentation Slides Supporting a May 16, 2014, Public Meeting to Discuss the Flood Hazard Reevaluation Schedule for the Monticello and Prairie Island Nuclear Generating Plants ML14058A1732014-02-19019 February 2014 Diesel Generator Steady State Voltage and Frequency Limits - Prairie Island Nuclear Generating Plant Meeting February 19, 2014 ML13210A2012013-07-29029 July 2013 2012 End-of-Cycle Slides - Licensee ML13210A2002013-07-11011 July 2013 2012 End-of-Cycle Slides ML13056A0262013-02-25025 February 2013 Regulatory Conference Slide Presentation ML12340A5402012-12-0606 December 2012 Reactor Core Cooling & Heat Removal FLEX Strategy - Phase 1 ML12326A9712012-11-21021 November 2012 Encl 3 (Handouts - Public) to Summary of October 24, 2012, Meeting with the Northern States Power Company, D/B/A Excel Energy Regarding Security Requirements and Changes Pertaining to Prairie Island TAC L24689 ML12277A1762012-10-0404 October 2012 Steam Generator Replacement Presentation ML12275A4652012-09-27027 September 2012 Meeting September 27, 2012 - Handouts ML12275A3782012-09-27027 September 2012 Xcel Energy Prairie Island Nuclear Generating Plant Meeting Presentation, Diesel Generator Voltage and Frequency Limits. ML12205A2172012-07-23023 July 2012 NRC 2011 End-of-Cycle Slides ML12205A2202012-07-17017 July 2012 Licensee 2012 End-of-Cycle Slides ML12115A3112012-04-24024 April 2012 Meeting Slides: 04/24/2012 Meeting with Xcel Energy NFPA 805 Presubmittal - Prairie Island Nuclear Generating Plant ML1207904792012-03-14014 March 2012 March 14, 2012 Telecon Slides ML1122803892011-08-18018 August 2011 Pre-Application Meeting for Prairie Island Nuclear Generating Plant (Ping) Extended Power Uprate (EPU) ML1119903462011-07-28028 July 2011 Meeting Presentation, Prairie Island Nuclear Generating Plant - Failure to Maintain the Train a and B Direct Current Electrical Power Subsystems Operable ML1117804242011-06-22022 June 2011 June 22, 2011, Meeting Handout #1 - NRC Meeting Diesel Fuel Oil LAR for Prairie Island Ngp ML1120701572011-06-22022 June 2011 June 22, 2011, Meeting Handout #2 - Proposed Technical Specification Changes for Prairie Island Ngp Diesel Fuel Oil LAR ML1106600792011-03-0303 March 2011 March 3, 2011 Meeting Handouts - Revise Footnote in TS 3.8.1, Prairie Island Nuclear Generating Plant ML1034701142010-12-14014 December 2010 Excel Energy Slides for Public Meeting 12/14/2010 to Discuss Human Performance Issues ML1027802642010-10-0404 October 2010 Session 4 - Heather Westra Presentation at October 4, 2010, Public Meeting on Groundwater Protection ML1023805712010-08-25025 August 2010 Meeting Presentation Alternative Source Term Steam Generator Tube Rupture Margin to Overfill Evaluation - Prairie Island Nuclear Generating Plant ML1014502432010-05-26026 May 2010 Responses to Questions from the Prairie Island Indian Community Concerning Issues Related to Prairie Island Nuclear Generating Plant ML1012604192010-05-20020 May 2010 Meeting Presentation Prairie Island Annual Assessment Meeting - Reactor Oversight Program - 2009 ML1012503422010-05-0505 May 2010 Regulatory Conference Slides ML1015801072010-04-28028 April 2010 2R26 Outage, SG Tube Inspection Telecon Slides ML1010604782010-04-15015 April 2010 April 15, 2010, Meeting Slides - Pre-Application Meeting for Prairie Island Ngp Extended Power Uprate ML0932901282009-12-0101 December 2009 Licensee Slides for Public Meeting 2024-05-07
[Table view] Category:Slides and Viewgraphs
MONTHYEARML24127A2402024-05-0707 May 2024 Presentation Slides for Prairie Island 2023 End-of-Cycle Meeting ML24059A4042024-03-0606 March 2024 March 6, 2023, Presubmittal Meeting for License Amendment Request to Modify Technical Specifications Definitions & Approve Plant-Specific Methods for Response Time Testing (EPID L-2024-LRM-0034) - Slides ML24029A0382024-01-31031 January 2024 January 31, 2024, Pre-application Meeting Presentation - Prairie Island ISFSI License Amendment Request to Add Grace to License Conditions ML23168A0032023-06-20020 June 2023 Handout for 6/23/2023 Pre-Application Public Meeting with Prairie Island Nuclear Generating Plant to Revise ISFSI TS 4.4 for TN-40HT Casks ML23156A2602023-06-0505 June 2023 2022 Prairie Island End-of-Cycle Meeting Presentation ML23102A1752023-04-14014 April 2023 April 14, 2023 TS 3.7.8 LAR Pre-Submittal Meeting Slides ML22130A5852022-05-10010 May 2022 2021 Monticello and Prairie Island Nuclear Generating Plant End-of-Cycle Meeting Presentation ML22048B1812022-02-18018 February 2022 Pre-Application Meeting for Prairie Island TS 5.6.6, PTLR, LAR ML21166A3792021-06-15015 June 2021 Units 1 and 2 2020 End-of-Cycle Meeting Presentation ML21124A0652021-05-0606 May 2021 Xcel Energy Presentation for May 6, 2021 Public Meeting to Discuss 24-Month Cycles at Prairie Island Nuclear Generating Plant, Units 1 and 2 ML21032A2632021-02-0303 February 2021 Slides for Public Meeting with Xcel Energy to Discuss a Planned Amendment to Combine the Emergency Plans and Create a Common Emergency Offsite Facility for Monticello and Prairie Island ML20266F1052020-09-23023 September 2020 (PINGP) COVID-19 Exemption Request for the 2020 Biennial Emergency Preparedness Exercise ML20212L8622020-07-29029 July 2020 2019 Monticello and Prairie Island EOC Presentation from Webinar ML20098F0682020-04-0909 April 2020 Preapplication Teleconference Presentation: License Amendment Request to Adopt TSTF-569 ML20057D3082020-02-18018 February 2020 Slides Potential License Amendment to Remove Note from LCO 3.4.12 and LCO 3.4.13 ML19268A0422019-09-26026 September 2019 Pre-Application Meeting License Amendment Request Revise Technical Specifications to Adopt Risk Informed Completion Times TSTF-505, Revision 2, Provide Risk-Informed Extended Completion Times - RITSTF Initiative 4b ML19210D4512019-07-22022 July 2019 Abeyance Seal Preapplication Meeting Slides ML19071A2782019-03-0707 March 2019 Enclosure 3: Meeting Slides (Summary of February 28, 2019, Public Meeting with Xcel Energy to Discuss Increasing the Amount of Special Nuclear Material Authorized for Storage at the Prairie Island ISFSI (W/Enclosures 1 and 2)) ML18162A0262018-06-12012 June 2018 License Amendment Request to Reclassify Certain Fuel Handling Equipment ML18051A1752018-02-20020 February 2018 Pre-Application Meeting License Amendment for TSTF-425 Relocation of Specific Surveillance Frequency Requirements to a Licensee Controlled Program Xcel Energy 2/20/2018 ML17240A3382017-08-30030 August 2017 Non-Safety Related Digital Feedwater and Amsac/Dss Control Systems Replacement Project Presentation ML17209A1192017-07-17017 July 2017 Summary of July 17, 2017, Meeting with Northern States Power Company, Doing Business as Xcel Energy, on Potential License Amendment Request Related to Heavy Lifting Devices ML17198A2632017-07-17017 July 2017 Pre-Application Meeting ML17066A3732017-03-0909 March 2017 Spent Fuel Pool Criticality Technical Specification Changes Round 2 Request for Additional Information Public Meeting: March 9, 2017 ML17037D1172017-02-0707 February 2017 License Amendment Requests for Change in Emergency Plan Staff Augmentation Response Times Pre-Submittal Meeting for Prairie Island Nuclear Generating Plant Monticello Nuclear Generating Plant: February 7, 2017 ML17023A0652017-01-24024 January 2017 Pre-Submittal Call Regarding License Amendment Requests for Prairie Island Nuclear Generating Plant, Units 1 and 2 and Monticello Nuclear Generating Plant Emergency Action Level Scheme Changes ML16280A0372016-09-29029 September 2016 Flood Hazard Reevaluation Report - Response to Requested Information (CAC Nos. MF7710 and MF7711) - Figure 2 of 3 ML16280A0422016-09-29029 September 2016 Flood Hazard Reevaluation Report - Response to Requested Information (CAC Nos. MF7710 and MF7711) - Figure 3 of 3 ML16280A0352016-09-29029 September 2016 Flood Hazard Reevaluation Report - Response to Requested Information (CAC Nos. MF7710 and MF7711) - Figure 1 of 3 ML15140A3342015-05-13013 May 2015 Public Meeting 05132015 Licensee Slides Only ML15127A6562015-05-0707 May 2015 PI EOC Mtg NRC Slides ML15105A0372015-04-14014 April 2015 Xcel Energy Slide Presentation to Support Pre-Application Meeting on April 14, 2015, to Discuss Nuclear Fuel Design Transition to Include Integral Fuel Burnable Absorber (Ifba) at the Prairie Island Nuclear Generating Plant ML14323B0222014-11-19019 November 2014 Regcon, November 19-20, 2014: 03-Info-Session-2 Ronald Johnson - Tribal Perspective on Continued Storage ML14162A5202014-06-11011 June 2014 Slides: Prairie Island Independent Spent Fuel Storage Installation - License Renewal Application - Discussion of Requests for Additional Information, for June 16, 2014, Public Meeting ML14153A0242014-05-16016 May 2014 Xcel Energy'S Presentation Slides Supporting a May 16, 2014, Public Meeting to Discuss the Flood Hazard Reevaluation Schedule for the Monticello and Prairie Island Nuclear Generating Plants ML14084A3242014-03-21021 March 2014 M140321: Slides - Presented by Multiple Participants at Commission Briefing on Waste Confidence Rulemaking ML13210A2012013-07-29029 July 2013 2012 End-of-Cycle Slides - Licensee ML13210A2002013-07-11011 July 2013 2012 End-of-Cycle Slides ML13056A0262013-02-25025 February 2013 Regulatory Conference Slide Presentation ML12340A5402012-12-0606 December 2012 Reactor Core Cooling & Heat Removal FLEX Strategy - Phase 1 ML12326A9712012-11-21021 November 2012 Encl 3 (Handouts - Public) to Summary of October 24, 2012, Meeting with the Northern States Power Company, D/B/A Excel Energy Regarding Security Requirements and Changes Pertaining to Prairie Island TAC L24689 ML12277A1762012-10-0404 October 2012 Steam Generator Replacement Presentation ML12275A3782012-09-27027 September 2012 Xcel Energy Prairie Island Nuclear Generating Plant Meeting Presentation, Diesel Generator Voltage and Frequency Limits. ML12205A2172012-07-23023 July 2012 NRC 2011 End-of-Cycle Slides ML12205A2202012-07-17017 July 2012 Licensee 2012 End-of-Cycle Slides ML12115A3112012-04-24024 April 2012 Meeting Slides: 04/24/2012 Meeting with Xcel Energy NFPA 805 Presubmittal - Prairie Island Nuclear Generating Plant ML1207904792012-03-14014 March 2012 March 14, 2012 Telecon Slides ML1122803892011-08-18018 August 2011 Pre-Application Meeting for Prairie Island Nuclear Generating Plant (Ping) Extended Power Uprate (EPU) ML1119903462011-07-28028 July 2011 Meeting Presentation, Prairie Island Nuclear Generating Plant - Failure to Maintain the Train a and B Direct Current Electrical Power Subsystems Operable ML1117804242011-06-22022 June 2011 June 22, 2011, Meeting Handout #1 - NRC Meeting Diesel Fuel Oil LAR for Prairie Island Ngp 2024-05-07
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Text
Prairie Island Nuclear Generating Plant NRC Region III Regulatory Conference Failure to Maintain the Train A and B Direct Current Electrical Power Subsystems Operable July 28, 2011
Agenda Opening Remarks - Mark Schimmel Sequence of Events - Kevin Davison Causes and Corrective Actions - Kevin Davison Regulatory Significance - John Bickel Operator Actions - Darrell Lapcinski Conclusion - Mark Schimmel Closing Remarks - Dennis Koehl 2
Opening Remarks Xcel Energy takes its obligation to protect the health and safety of the public very seriously Violation Failure to maintain the Train A and B direct current electrical power subsystems operable Agree with the performance deficiency and violation Disagree with the significance More than adequate time to diagnose charger lockup 3
Sequence of Events Kevin Davison - Plant Manager 4
Sequence of Events 1994 / 95 1997 1999 2005 Oct 2010 Feb 2012 Battery Follow up Test 12 Battery TS 3.8.1.B Unit 2 chargers testing of procedure Charger mod Entered for battery installed Unit 1 revised to cancelled D2 EDG; chargers to battery remove 12 Exigent TS be replaced chargers Battery change Charger approved 1994 1997 2000 2003 2006 2009 2012 June 2010 Site staff 1996 2002 enters 12 May 2011 12 Battery 1999 Improved Battery Unit 1 Charger Battery Standard Charger battery lockup charger mod Tech Spec testing issues chargers during ISI requests implemented into CAP replaced 5
Causes and Corrective Action A root cause analysis was performed to identify the direct cause and the organizational and programmatic breakdowns that led to failure to correct battery charger lockup.
6
Causes and Corrective Actions Root Cause - Direct The organization had developed a blind spot to this issue.
Over several years, multiple opportunities surfaced to identify and correct the condition 7
Causes and Corrective Actions Root Cause - Programmatic RC-1: Equipment issues become long-standing when C severity level CAPs are allowed to be closed to a secondary work process deliverable, which may be canceled or extended beyond the original CAP due date.
Root Cause - Organizational RC-2: Behaviors necessary to drive long-standing equipment issues to timely resolution are neither modeled, nor required by Plant Health Committee (PHC).
8
Causes and Corrective Actions Corrective Action - Equipment Implemented compensatory actions for all battery chargers Obtained an Exigent Technical Specification change Replaced and retested Unit 1 Battery Chargers (1R27)
Scheduled replacement of Unit 2 Battery Chargers (2R27)
Procurement of Spare and Unit 2 chargers in progress.
9
Causes and Corrective Actions Corrective Action - Process For C severity level CAPs, to ensure all open equipment issues remain captured in the corrective action process.
Establish a PHC Charter and changed behaviors that incorporates the knowledge gained from benchmarking industry leaders and make it available to System and Programs Engineering.
PHC needs to be defined as the champion of projects for presentation to PRG.
10
Causes and Corrective Actions Corrective Action - Process Implement a periodic PHC roll-up to evaluate effectiveness of resolving equipment Legacy Issues Plan 11
Conclusion Station had multiple opportunities to identify Corrective actions have focused on:
Replacement of chargers Changing behaviors of PHC members Process changes to assure sustainability 12
Regulatory Significance Scenarios & Risk Evaluation John Bickel - PRA Consultant Engineer Operator Actions Darrell Lapcinski - Shift Manager 13
Regulatory Significance - Scenarios LOOP event with EDG D1 failed and 12 Battery Charger Lockup Scenario is most limiting time available prior to battery depletion Plant emergency lighting powered from the 12 battery Minimum design voltage on 12 battery will be reached in three hours Most risk significant sequence from the PINGP PRA evaluations Noted by the NRC to be significant risk contributor Failure of the EDG D1 would cause the operators to perform additional actions LOOP event with 11 and 12 Battery Charger Lockup EDG D1 successfully operates Scenario is not as limiting in time as scenario listed above Plant emergency lighting powered from the AC source (EDG D1 operates).
Minimum design voltage on 11 battery reached in six and a half hours.
Minimum design voltage on 12 battery reached in seven and a half hours.
14
Regulatory Significance - Scenarios LOOP, EDG D1 Failure & 12 Battery Charger Lockup T< 1 T=180 T=0 T<1 T<60 Time for Operators to Diagnose, Cross-tie Buses & Reset Charger LOOP Occurs DG Start Signal 12 Battery Reaches EDG Minimum Design loaded & Voltage Failed; Charger Timeline in minutes lockup 15
Regulatory Significance - Scenarios LOOP, 11 & 12 Battery Charger Lockup T< 1 T=390 T=450 T=0 T<1 T<60 Time needed for Operators to Diagnose
& Reset Charger LOOP Occurs DG Start Signal 11 Battery 12 Battery EDG Reaches Reaches loaded; Minimum Minimum Charger Design Design lockup Timeline in minutes Voltage Voltage 16
Operator Actions - Immediate Immediate Actions Following LOOP Event (memorized actions) 1E-0 Reactor Trip or Safety Injection Step 1: Verify Reactor trip Step 2: Verify Turbine trip Step 3: Verify Both Safeguards Buses - Energized Lead Reactor Operator (RO) will recognize that EDG D1 has failed and Bus 15 is deenergized.
Response Not Obtained: IF one bus deenergized, THEN initiate action to restore power to deenergized safeguards bus per 1C20.5 AOP1, REENERGIZING 4.16KV BUS 15.
Step 4: Check if SI is Actuated Operators will transfer to 1ES-0.1, Reactor Trip Recovery No Safety injection 17
Operator Actions - Trip Recovery Transition to 1ES-0.1, Reactor Trip Recovery Control Room Supervisor (CRS) will restore normal alarm response protocol per FP-OP-COO-01 Conduct of Operations, Attachment 1 Alarm Response.
Crew Brief will be performed.
CRS will direct the ROs to perform a board walkdown and report any alarms that are unexpected for the LOOP/reactor trip.
Operators are trained to look at electrical sources following LOOP event. Pattern of annuciators will also be evident.
18
Operator Actions - Emergency Plan Shift Manager Assumes Role of Emergency Director Within 15 minutes, Emergency Planning classification is required To determine escalation criteria, Shift Manager will evaluate alarms on electrical power panel Multiple people through multiple proceduralized paths give many opportunities to diagnose lockup of a battery charger.
19
Operator Actions - Control Room Unit 2 Unit 1 20
Operator Actions - Control Room Control Room from the Unit 1 side. The electrical power annunciator 21 panel is shown between Unit 1 and Unit 2 Control Rooms where it can be easily seen and monitored by both units operators.
Operator Actions After the plant is stabilized the operators will walk the panels.
During a LOOP, the power panel will be a priority.
The difference in the pattern for Unit 1 and Unit 2 Annunciators will be quickly identified.
Operators are trained to identify discrepancies to the norm.
22
Unit 2 G-Panel Alarms Unit 1 G-Panel Alarms 23
Operator Actions - Restore Bus 15 Per 1E-0, Step 3 RNO:
IF one bus deenergized,THEN initiate action to restore power to deenergized safeguards bus per 1C20.5 AOP1, REENERGIZING 4.16KV BUS 15.
Unit 1 SS will instruct Unit 1 Lead RO to enter 1C20.5 AOP1 per 1E-0.
Dispatch outplant operator to locally check EDG D1.
Per 1C20.5 AOP1, it would be determined that no lockout exists on Bus 15 and is available for repowering Due to LOOP event and D1 EDG failure, Bus 15 will be reenergized via bus-tie breakers per 1C20.5 AOP4.
24
Operator Actions - Charger Restart Cues Available To Operator 12 DC System Trouble Alarm (47024-1105) 12 DC Panel Undervoltage Alarm (47024-1204)
Alarm Response Procedures (ARP) will instruct operator to review battery data indication on the Emergency Response Computer System (ERCS).
25
Operator Actions - Charger Restart Operators are trained to use all available indication. The Emergency Response Computer System (ERCS) will be initiated to determine 26 status of the batteries. This screen is available on the power panel and would continue to have power during a LOOP.
27 28 29 30 31 Operator Actions - Charger Restart Procedure Instruction to Restart Battery Charger ARP will also refer operator to 1C20.9 AOP4: Failure of 12 Battery Charger.
1C20.9 AOP4 (Attachment B) - Rev 10, provides instruction to restart battery charger.
Outplant operator required.
Outplant Operators Available to Respond Two Turbine Building (TB) Operators per Unit (4 total).
Two of the operators (one per unit) perform immediate actions of 1ES-0.1, Attachment J.
Two TB Operators available to respond to EDG D1 failure and 12 Battery Charger.
In addition, although not credited in the PRA analysis, Auxiliary Building (AB) operator (2 total) can be available to respond to TB issues since this scenario would not require outplant actions in the AB.
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Operator Actions - Charger Restart Complexity of Task and Time To Complete Action Simple action, open and close AC Input Breaker on front panel.
Both the control room and outplant action times were confirmed during two simulator case studies.
Approximate time to complete Bus 15 repower and restart of 12 battery charger actions based on two simulator case studies: less than 60 minutes 33
Operator Actions The only manual action required to physically reset the battery charger is to switch the AC Input breaker shown above on the left from the Off to the On position. 34
Operator Actions - Conclusion T-0 LOOP w/ D1 Failure AOP to Restore 1E-0 Trip and SI Bus 15 Bus 15 Restored 1ES-0.1 Trip Recovery 12 DC Trouble Alarm 12 DC Panel UV Alarm Operator Cues Computer alarms / indications EAL Escalation Criteria ARP & AOP Failure of 12 Procedures Battery Charger Simple Action Response Directed by Procedure Battery Charger Reset T-60 35
Risk Evaluation Key Risk Significance Question:
Do operators have enough time to detect and reset tripped battery charger, before batteries become unavailable ?
Xcel HEP analysis: HEP=8.9E-4 (EPRI HRA Calc.)
NRC analysis: HEP=2.2E-2 (SPAR-H) 36
Risk Evaluation RASP Manual Vol.3 Section 2.3 requires:
Technical reviews. Check whether a knowledgeable specialist reviewed the reasonableness and acceptability of the results of the thermal hydraulic, structural, or other supporting engineering bases that were used to justify the success criteria. (SC-B5)
Fidelity to as-built design:
For CCF of Battery Chargers scenario with both diesels running (no emergency lighting loads on battery) - 7.5hr battery capacity For D1 diesel failure and 12 Charger trip - 3hr battery capacity 37
Risk Evaluation RASP Manual Vol. 1, Section 6.3.1 requires considering following in the recovery analysis:
Demonstration that the action is plausible and feasible for the scenarios to which recovery/repair action are applied (HLR-HR-H).
Availability of procedures, operator training, cues, and manpower (HR-H2).
Relevant scenario-specific performance shaping factors in the HRA (HR-H2 and HR-G3).
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Risk Evaluation 39
Risk Evaluation To obtain HEP=2.2E-2, NRC SPAR-H treatment omits consideration of available time With common cause charger failure and D1/D2 operable: 7.5 hrs available for recovery With D1 failing and lighting transferred to battery: 3 hrs available for recovery Per the SPAR-H model:
1hr to detect/reset 3hr batteries (expansive time) 1.5hr to detect/reset 3hr batteries (expansive time) 1.5hr to detect reset 2.5hr batteries (extra time) 40
Risk Evaluation 41
Risk Evaluation Peer Review of SPAR-H model Page I-17 of NUREG/CR-6883states:
We do reduce the HEP for at-power situations where there is extra or expansive time available, beyond a certain time minimum corresponding to interpretation of the THERP diagnosis curves.
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Risk Evaluation In conclusion, if NRC were to consider:
As-built, As-operated battery capacity Time available for resetting tripped charger for the dominant sequences of interest Per SPAR-H process there is Extra/Expansive time Risk significance is GREEN.
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Conclusion Mark Schimmel - Site Vice President 44
Closing Remarks Dennis Koehl - Chief Nuclear Officer 45
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