IR 05000341/1987036

Safety Insp Rept 50-341/87-36 on 870824-27.Violations Noted. Major Areas Inspected:Inadvertent Closure & Opening of Inboard MSIVs & Previously Identified Items

ML20237L659
Person / Time
Site:	Fermi
Issue date:	09/03/1987
From:	Darrin Butler, Phillips M, Rescheske P NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III)
To:
Shared Package
ML20237L644	List: IR 05000341/1987036 ML20237L641 ML20237L646
References
RTR-NUREG-0737, RTR-NUREG-737 50-341-87-36, NUDOCS 8709090023
Download: ML20237L659 (10)

Text

_ _ __ ._- . .. .

,

-

.-

. r U.'S. NUCLEAR REGULATORY COMMISSION

REGION III

Report No.:50-341/87036(DRS)

a Docket No. 50-341- License No. NPF-43

. Licensee: . Detroit Edison Company 2000-Second Avenue-Detroit, MI- 48224 Facility Name: Enrico Fermi Nuclear Power Plant, Unit 2

.- Inspection At: .Enrico Fermi 2 Site, Monroe, Michigan

- Inspection Conducted: August 24-27, 1987

_h hath, / /

Inspectors: D. S. Butler Y/8/[7 Date

,, ,

l& . escheske 09 /a3 /J7 Date

.:--

" Approved By: Monte . Phi lips, Chief 7!7 7 Operational Programs Section Date Inspection Summary Inspection on' August 24-27, 1987 (Report No. 50-341/87036(DRS))

Areas Inspected: Special unannounced safety inspection of actions taken on previously-identified items, and the inadvertent closure and reopening of the inboard Main Steam Isolation Valves (IE Module 92701).

Results: Of the two areas inspected, one violation of Technical Specifications was identified - inadequate safety-related procedure as required by Technical Specification 6.8.1 (Paragraph 3.b). The violation was considered to have minor safety significanc ~

- 8709090023 070904

. PDR ADOCK 050003 G PDR g r

C___ .__ _____.m_.m_____ __..__ ._

. _ _

- _ _ _ _ . _ _ _ _ _ _ _ _ - - - _ _ _ - _ ,

,

, V

,

DETAILS Persons Contacted R. S. Lenart, General Director, Nuclear Engineering S._Cashell, Licensing Engineer-T.. Dong, Plant-Safety J. Green, Supervisor, I&C, Nuclear Engineering F. Svetkovich, Technical Engineer W. Tucker, Superi4tendent, Operations LJ. Wald, Supervisor, Plant Quality. Assurance The above persons attended the exit meeting on August 27, 1987.

The inspectors also interviewed other licensee personnel during the course of the inspection . including members of the Operations, Engineering, and Training Department . Followup on-Previously' Identified Items (Closed) Unresolved Item (341/86032-01(DRP)): Calibration of safety-related primary element temperature sensing device The licensee's Technical Specification (TS) definition (Section.1.4) for Channel Calibration states, in part, that the Channel Calibration shall encompass the entire channel, including the sensor and alarm and/or trip function The licensee was using three methods to assess temperature channel integrity. They were comparison checks with' redundant sensors,

,

operator qualitative' assessment for expected operating' temperatures, and pre'and post connection comparisons. -The licensee s methods

+ were submitted to the Office of Nuclear Reactor Regulation (NRR) to-determine how the TS definition applied to temperature sensors. The NRR staff found Detroit Edison's practice for conforming to the intent of the TS calibration requirements for temperature sensors to be reasonable, based on normal industry practice, and therefore acceptable, (Closed) Open Item (341/87003-01(DRS)): Development of minimum acceptance criteria for AT. temperature channels, and. instructions for the operators where an assessment of AT is required in Surveillance Procedure No. 24.000.02, "Shiftly, Daily, Weekly and Situation Required Surveillance." The procedure was modified to include minimum AT acceptance criteria. A note was added instructing the operators to contact I&C-if a reading of zero was observed on AT temperature channels; I&C would then verify channel operabilit The licensee's actions regarding this Open Item are considered acceptabl _ _ _ _ - _ _ - _ _ _ _ _ _

-

. - _ - - - -- ____ - . - - . _ _ - _ - _

,

. MSIV Inadvertent closure and Opening

' Background On August 4,51987, with the reactor in cold shutdown, a closure of x the four inboard MSIVs occurred during'a manual transfer of the Division II RPS to its alternate power supply. The Division I RPS

.had previously been transferred to.its alternate power supply, and the affected system logics had been reset per system operating procedure P0M 23.316,1"RPS 120V AC AND RPS MG SETS." The inboard MSIVs subsequently reopened when procedure steps in POM 23.316 I instructed the Reactor Operator (RO) to reset the MSIV isolation logic following the transfer of the Division II RPS.' The four ]

outboard MSIVs remained opened during the above mentioned power *

. supply transfers. The NRC was nooified of the closure and reopening of the inboard MSIVs, and the licensee was preparing LER 87-03 The licensee was required by TS 4.8.4.4.a to perform a six month

' functional test of'the RPS breakers (Electrical Protection Assemblies). A transfer from the normal motor generator RPS power suppiy to its alternate supply was required for testing the breaker This. test has been performed ten times since

. December 198 The MSIVs did not respond as described above during any of these functional tests. The inspectors could not determine the position.of the MSIVs; however, it was assumed that they were closed during those tests. Review of the MSIV logic indicated that-if the MSIVs were closed, they would remain closed during snd after RPS power supply transfer, System Description-The purpose of the Nuclear Steam Supply Shutoff System (NS4) is to isolate the primary and secondary containments during accident conditions to limit the release of radioactive materials. Group 1 isolation valves are associated with the Main Steam System (B21).

The isolation valves associated with Group 1 are the inboard and outboard main steam isolation valves and the inboard and outboard main steam line drain valves. This discussion will be limited to the inboard MSIVs. The MSIVs may be manually closed or opened by the R0. Automatic closure is provided by the NS4 as determined by plant conditions. The MSIVs are air and spring operated valves; air to open, air and/or spring to close. The air necessary to open the valves is supplied through either an energized AC or DC solenoid valv Normal valve configuration has both solenoids energized when the logic has been properly reset. The valve closes when both solenoids are de-energized. The valves close to a fail safe condition on a loss of both power supplies or loss of ai During the transfer of Division I ('A' Logic) power, the following relays and solenoids changed state and the MSIVs remained open (see attached figure):

l

_ _ - - - _ - _ - _

, .p

'

JR M* , '

, . .G

m,-

,

i' l ,

- -

..; .

,

,

'

t i

1. .NS4hN' Logic LL LK14 s .

de-energized

q < K49A 0 pen /Close ('A')- de-energized .a ygMM);.tal _

,

K7A- NS4 Logic ('A'). t_

de-enargized

-

y

3~

'

.K7CL N54 Logic ('A')/ de-energized _ " x'

.. .

e 3 n-

'~

-  :!'AC Pilot',Solenoidsf(' A') . de-energized ?

y . -

r t, m

~, 10CNilotLSolenoids.('B')b'

j

-

.ym 'energilzed

,_ ,

y K51 s

,}M4'B' Logic- energized K81 SMpiwal Open/Close ('B')' energized ,q

,J V ..

'K78 x >

' NS4' Logic ('B') .

energized <

K7D 4 NS4 Logic ('Bl)= energized Procedure P0M :23.316 ' instructed the RO to reset the NS4 A/B logic.'

This allowed (per # sign) for the ' A' trip logic to rese The n configuration yns as follows (the MSIVs remained open):

.,

j h>

K14 _NS4 'A Logic energized t - -

i s ,

K49A- Manual'Open/Close l'A') ^ remainedde-energizeb]f K7A NS4.Logik' energized- ,

N9p

'K7C NS4tLogic energized' cJ'

._ AC~ Pilot" Solenoids ('A') remained de-energized

-

DC Pilot Solenoids ('B') energized-K51 NS4 'B' Logic energized-K81A Manual Open/Close ('B') energized K78- 'NS4 Logic'('B') energized

K7D' - _

tlS4 L4gic ('B') energized During the transfer of the Division II ('B' Logic) power, thn configurat_ ion was as follows (the MSIVs closed):

.

'A' Logic energized

[ K14

\

NS4 K49A . Manual.Open/Close ('A') remained de-energized K7A (4 ( NS4q ogic ('A') energized

.

C (

'

-- -

.__-----_--_J

twww w;

- -

,

],

,

L- . . . .

.,

.-

p Q

_"

K7C- NS4 Logic ('A')- energized p/

%c Ls

, ,,

_

AC Pilot Solenoids ('A') remained de-energized

- '

DC Pilot' Solenoids ('B') .'de-energized K51 NS4 'B' Logic de-energized K81A Manual Open/Close ('B') energized j

.p' .

K78 NS4 Logic ('B') de-energized

'

K7D NS4 Logic ('B') de energized l%

The'. inboard MSIVs closed.due to the de-energized state of both 3-solenoids. Procedure P0M 23.316 did not include steps to instruct i

.3 4

' ~'

g' the R0 to press the MSIV "open" push buttons to energize i (through K49A) the AC Pilot Solenoids. This would have prevented l the inadvertent closure of'the inboard MSIV JrY . .. ,

p The NS4 A/B. Logic was reset; where upon, the inboard MSIVs opene !

- Th= configuration was as follows: l 9 K14 NS4 'A' Logic

. energized i

r K49A- Manual Open/Close ('A') remained de-energized l K7A NS4 Logic ('A') energized i

!

K7C- NS4 Logic ('A') energized  ;

-

-AC Pilot Solenoids ('A') remained de-energized I

-

DC Pilot Solenoids ('B') energized l K51 NS4 'B' Logic energized K81A Manual Open/Close ('B') energized K78 NS4 Logic ('B') energized K7D NS4 Logic ('B') energized I

The inboard MSIVs opened due to the energized state of the DC solenoids (through K51).

The Fermi Unit 2 Technical Specification 6.B.1 requires the licensee to establish, implement, and maintain written procedures covering surveillance and test activities of safety-related equipment. The >

root cause of the event described above was the inadequacy of procedure POM 23.316. This is considered to be a violation

.(341/87036-01).

,

,

_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _J

_

I

-

,

F The licensee has modified procedure POM 23.316 to instruct the operator to press the individual MSIV "open" push buttons (if the MSIVs are-open) following the reset of the MSIV logic. The outboard MSIVs would have responded in the same manner as the inboards, if

'

the power supply transfer was reversed (Division II RPS transferred first). The inspectors verified the adequacy of the procedure changes to prevent recurrence of this event. The changes were satisfactory for both inboard and outboard MSIVs, and a written response to this violation is not require i Safety Significance The inspectors reviewed this event for a potential unreviewed safety question (inadvertent MSIV closure and reopening) and for compliance with NUREG-0737 II.E.4.2 ("The design of control systems for automatic valves is such that resetting the isolation signal will not result in the automatic reopening of containment isolation valves").

(1) The closure of the MSIVs at power was currently addressed in FSAR Section 15.2.4. The MSIV closure would initiate a reactor scram and the primary system pressure would be controlled by the safety relief valves. The postulated scenario where the MSIVs reopened after a scram was considered within the bounds of existing analysis by the licensee and General Electric Company. The analysis indicated that post scram abnormal operating procedures would be governing the operators' actions and that the MSIV logic would not have been reset following the scram. Licensed operators interviewed on this subject concurred with the analysis. Furthermore, the MSIVs would see a high differential pressure across each valve which would make.it virtually impossible for the MSIVs to reopen. If the valves did open, depressurization and reactor cooldown would be automatically controlled by redundant pressure controllers via the main steam bypass syste The Training Department ran the following four sce.narios for the inspectors on the Fermi Unit 2 simulator utilizing the version of procedure POM 23.316 involved in this event:

(a) The initiating event (Shutdcwn)

(b) Pre-criticality (Startup)

(c) Critical (Startup, < 1% Power)

(d) 100% power In cases (a), (b), and (c), the simulator followed the initial sequence of events and the inboard MSIVs closed and reopene There appeared to be little or no changes to the primary system

- _ _ _ - _ _ - _ _ _ _ _ _ - _ _ _ _ _ _ _ _ _ _ _ - - _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ - _ _ _

.

-

-

, ,

- -

- - - - - - - - -

t >

, -

l

~ ' ,

.

~

1f,

/ j ., r h:-[ - ?dnd the reactor. The ion stkam line pressure and MSIV < 92% _ I

'7 open interlocks were bypu, sed and, therefore, a reactor scram l

'

'was not initiate ~

<

) -

In case (d), the closure of ths MSIVs initiated a reactor scra I, f " As the inboard MSIVs closed, a low steam line pressure trip signal also produced a Group 1 isolation signal. The outboard,

[' ! -

,

j IGIVr closed and none,of 'tte MSIVs would cpen with a true

/, =

isolition signal preser;t. The Group 1 isolation signal was reset and all the. MilVr remair.ed close j /; >3

,

j(2) TheinspectorsreviewestheMSIVlogicdrawingstoensurethat y true ' solation signal. Isolation plus loss of AC, isolation

'

+< <

-i ' plus Icss of DC, and is11ation plus loss of all power would

'

j inithte aiMSIV closures Upon power restoration, the inspectors vepified the flSIVs Wod d not open when the MSIV logic was reset. Ir; eil of the' dove cases, the inboard and outboard MSIVs remained closed.' y

.

The inspectors determined from their review that an unreviewed safety question did not exist and that the Fermi Unit 2 design >

was in full compliance with NUREG-073 Training Impact The licensed operator;'were trained on isolation logics involving an automatic or manual isolation. .This eveat was different from the training provided in that the event.did not involve a system f isolaMo The Training D@ artment indicated that licensed operatprs would review the completed LER in the required reading

/, / program and in requalif(cation traininge It appents that training

• /. .

would not have prevented the event. TpeF.0wasfollowingstepsin

/ '/ an inadequate procedura, tj J , So31ectiveActions e . As a result of this event several corrective actions were

, )} implemented, including revision of procedure P0M 23.316 as s described in Paragraph 3.b. The licensee has completed a review

'

-

of_all isolation logics in TS Table 3.3.2-1 and concluded they were in, full compliance with NUREG-073 A hardware change was being propased to ensure proper operation of manual valve control after RPV pwer supply transfers. This will reinforce procedure PJM 23.316 by requiring appropriate operation of the HSIV open/close push buttonc During:the review of P0M 23.316,~the inspectors noted a step that, i required the'R0 to verify the AC Pilot Solenoid was energized by

! observing current flow in the solenoid circuit ammeters. The f r' ammeters were located in the relay rooa, two floors below the main f control room. The inspectors recommend that the licensee install

.;

>s-

'

'

..F

-...-_----___.n_ - - . . - - _ - . - _ _ _ _ ~ h

.. _ _ _ _ _ _ _ _ _ _ .

.

.

the AC and DC ammeters in the main control roo This would facilitate the ease at which the R0s could verify the " state" of the MSIV solenoid Licensee corrective actions appear to be adequate; therefore, the inspectors have no further concerns regcrding this even No additional violations or deviations were identifie One recommendation was discussed in Paragraph . Exit Interview The inspectors met with the licensee representatives (denoted in Paragraph 1) on August 27, 198 The inspectors summarized the scope

, and findings of the inspection. The licensee acknowledged the statements

! made by the inspectors with respect to the violation. The inspectors also-discussed the likely informational content of the inspection report with regard to documents or processes reviewed by the inspectors during the inspection. The licensee did not identify any such documents / processes as proprietar Attachment: Simplified Inboard MSIV Logic for Valve B21-F022A

_ _ . _ .

y

'A

'

_

_

M n"adM h*vi

' l' s S > 8 y

,

,

-

g s~ 'B '

-

a o os a -

_ l R

e

(

S N

4d i

o s*sne nes

" el o

" pol l

R e

S N

(

g g t A n os c t A s 9 4 e s 1 1 e 4 1 Cl e 8 5 Cy T K K A o K K D g g

S

_ - _ - ..

.

.

.

A - ~

_ _ ]g

- _

- - _

_

)

'A

'

(

S P

R I

)

) n y y o a a i l l s e e i r r

i v l l D a A a A u 9 u c 1 n 4 n d 8 a

_ Ka V K m A m A (

9 1 - . _ ( 0 1 l; , ,

K

-

~ $.

_

e

1

K n e

, . _ ~[

.

.e A

- ~

~

-

_

s - - ~ p- s o - -

O - _o n -

,_l N.,~~_[l o .C

_ ~ -

,

.

'

'

., C t ~

l L

.

t

_

u -

'

_

) - b

'

_

'

- nh

_

_

_

_ A es

_

.

_

'

(

pu O P , '

1. '

_

_

S rl P l b

,

l li R

y -

gI I l n 4A C p p

d li

.l f

l l k

o S u en r i Nf rs s o o s oo ot r i n ,re l t n , e .

v os C u o S ws i sS w b ,

P or D noP o h nn R pe c

el R p s eo f p u pi I I n a o ,II P ot CI I a V n .

aA r sonns sl nnt 0 ti oor t of oo 2 ct iie cs oiiy 1 aas sf ai ssl t l ii n t sii p novva n4 s vvp

_

3osiir CiDD t oS oiiu CNl DD s p

- A _

-

-

- - _ -

C A 4 9 B 1 7 7 1 7 7 5 K K K g K K

_

p p

_

_

i i

_

_ _ - rc ~ - r

_

_

_

Ti g .

T

_

_ _

_ - ~ _

_

_

C o C

_

_

AL D

_

_

_

_

_

_

.

.

-

.

fl

%

USHRC-OS 1981 SEP -8 A 911I

- - .

.

- - . _ - - - . - - - - . _ - . - _ _ . -_ __