ML20134E415

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Forwards Ltr Received by Regular Mail for Response to Concerns Re Clarification of Safety Concerns at Connecticut Yankee
ML20134E415
Person / Time
Site: Haddam Neck File:Connecticut Yankee Atomic Power Co icon.png
Issue date: 07/31/1996
From: Blanch P
AFFILIATION NOT ASSIGNED
To: Zwolinski J
NRC
Shared Package
ML20134D719 List:
References
NUDOCS 9611010158
Download: ML20134E415 (3)
v • d • e


Text

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

1 From: PAUL M. BLANCH <PMBLANCH@ix.netcom.com>

i To: John Zwolinski <JAZ@nrc. gov >

Date: 7/31/96 6:46pm

Subject:

CY PROBLEMS 7/31/96 John A. Zwolinski, Deputy Director Division of Reactor Projects -L/II Office of Nuclear Reactor Regu'ation Washington, DC 20555-0001 John:

The following letter was received today by reaular mail. "he only editing I did was to remove the author - 89s name and address. I will be interested in seeing your response to his concerns.

Sincerely, Paul M. Blanch

! 135 Hyde Rd.

West Hartford CT. 06117 860-236-0326 4

)

. l I

i 9611010158 961024 PDR ORG NRRA PDR

7/31/96 J Wayne D. Lanning Director - Millstone Oversight Team Nuclear Regulatory Commission 475 Allendale Road KingofPrussia,PA19406 J

SUBJECT:

SAFETY CONCERNS AT CONNECTICUT YANKEE The purpose of this letter is to clarify the safety concerns identified in the information package I sent to you on 7/10/96. 1 identified three safety l concerns in the package.  ;

which

" The first concern is a system that isinvolved required the toReactor Vessel safely shut down Level the Indication plant in theSystem,t even of a loss oT reactor coolant. NRC Regulatory Guide 1.97 requires the system to provide redundant monitoring from the top of the reactor core to the top of the reac;or vessel.

3 l The way the technical specifications are written at CY most of the indication j is allowed to be lost with no corrective action reguired. When one indicator is lost it is like driving at night with one headlight you can still see.

i At CY in, the late 1980's and early 1990's, both orimary,and backup indicators t were lost at several locations from the top of the core to the top of the vessel. It was like driving at night with no headlichts. CY responded by changing the emergency procedures to use alternate Tess accurate indication.

i It was like telling the operators to hold a flashlight out the car window.

4 Although it was questionable whether there was enough indication to handle a loss of reactor coolant accident, this was not my concern. My concern was it seemed to take months to hand the operators a i

after the lights flashlight. The went changeout,tried I to make in 1992 would reguire a timelv update

. of the emergency procedures when critical indication is lost. This change should be implemented before the plant restarts.

The second safety concern involves the technical specifications for eleven reactor trip setpoints. Concerns about the quality of the setpoint

, calculations were raised in the mid 1980's

! According to the latest industry guidelines, for butcalculating were ignored until 1994.

setpoints the i setpoint allowable values in a number of the CY technical specificatio,ns are Steam i

not valid. The invalid values Steam include: RCSLowFlowReactorTrip[PSCRe/

Line Break Flcw Reactor Trip v Feed actor i

2 Flow Mismatch Hi Pressurizer Level Reactor Trio, Reactor Trip HCP Reactor Trip POR9 Actuation Trip, Core Deluge Actuation, RHR Valve Permiss,ive, NIS Power Ran,ge Permissive, f7 &

P8 Permissives.

The present operations manager at CY suppressed these concerns for years by ignoring them when he was the plant instrumentation mana er. When I raised the concerns to him personally in a 1994 meeting, he sim ly claimed the setpoints were safe, and refused to discuss the reasons hey might be unsafe.

An automobile comparison would be like a town manager refusing to review speed limits to the latest safety standards. Assume a car stops 50 feet on dry pavement after you apply the brakes. If new safety information comes wt that says you should leave an additional 25 feet for adverse road conditions, and an additional 25 feet for the driver to react then you should allow 50 + 25 +

4. 25 = 100 feet of stopping distance to be safe,. The present CY allowable i values are based on 50 feet. CY should correct the technical specifications, and have NRC approval of the changes before they continue to operate.

The improper allowable values leads to the final safety concern. It is not 1

i possible to do pr per safety evaluations with improper allowable values. When instrument error such as drift' is checked during shutdown at CY it is sometimes found o tside the lim ts calculated to be safe, limits r,eferred to i

3 as the acceptance criteria. This is common at all plants and has happened hundreds of times at CY. The concern is when this happens at CY there is no method in place to evaluate whether safety limits were violated,,and whether a setpoint change is needed to ensure safe ' operation in the future.

assume the CY setpoints have been u To uselatest to the *.he automobile safety standards, analogy and again, leave 100 feet for the car to stop.pdated The

procedures still say the brakes should stop the car in 50 feet, which is fine.

NowassumewhenbrakinkionmethodatCYdistance feet. With the evalua theyiswo checked, it is sometimes found sincetowe be 80 we have 20 feet to spare"uld say: Wrong.

"no If problem,d you nee 80 feet have 100 feet for brakin 25tofeet stopfor road conditions and 25 feet for driver reaction, 80 +

25 + 25 g$0.

1 You now need 130 feet to stop safely.

What do I expect from the NRC7 I expect the concerns to be reviewed by the and I expect to be contacted for more information.

NRC the NRC withtoexperts,ine determ in a few weeks whether the concerns are valid, andI expect whether CY should resolve these concerns.

At the August 7th NRC public meeting in Waterford, I will listen for any

progress made investigating these concerns.

Former CY Design Engineering cc: Paul Blanch, Greg Wingard CC: ERNIE HADLEY <ECHADLEY@aol .com>

4 1

I i

~

2

From: PAUL M. BLANCH <PMBLANCH91x.netcom.com>

To: John Zwolinski <JAZ9nrc. gov >

Date: 7/31/96 6:46pm subject: CY PROBLEMS 7/31/96 John A. Zwolinski, Deputy Director Division of Reactor Projects -I/II Office of Nuclear Reactor Regulation Washington, DC 20555-0001 John:

The following letter was received today by regular mail. The only editing I did was to remove the author = B9s name and address. I will be interested in seeing your response to his concerns.

Sincerely, Paul M. Blanch 135 Hyde Rd.

West Hartford CT. 06117  !

860-236-0326 I

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I 1

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-Q&MT sfp ,

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7/31/96 WayneD.Lannin!toneOversightTeam Director - Mill Nuclear Regulatory Commission 475 Allendale Road KingofPrussia,PA19406 .

SUBJECT:

SAFETY CONCERNS AT CONNECTICUT YANKEE The purpose of this letter is to clarify the safety concerns identified in the information package I sent to you on 1/10/96. 1 identified three safety concerns in the package.

which The first concern is a system that isinvolved requiredthe to Reactor Vessel safely shut downLevel Indication the plant in theSystem,t even of a loss of reactor coolant. NRC Regulatory Guide 1.97 requires the system to ghereactorvesselrovide redundant monitoring from the top of the reactor core to the top of W

is way the to allowed technical be lost specifications are written with no corrective at CY,d.most action reguire of the indication When one indicator is lost it is like driving at night with one headlight you can still see.

At CY in, the late 1980's and early 1990's, both primary,and backup indicators were lost at several locations from the top of the core to the top of the vessel. It was like driving at night with no headliahts. CY responded by l changing the emergency procedures to use alternate Tess accurate indication.

Itwasliketellingtheoperatorstoholdaflashlightoutthecarwindow.

Although it was questionable whether there was enough indication to handle a loss of reactor coolant accident, this was not my concern. My concern was it seemed to take months to hand the operators a after the lights flashlight. went out,tried The change I to make in 1992 would reguire a timely update of the emergency procedures when critical indication is lost. This change should be implemented before the plant restarts.

The second safety concern involves the technical specifications for eleven reactor trip setpoints. Concerns about the quality of the setpoint l calculations were raised in the mid 1980's According to the latest industry guidelines, but for were ignored setpoints calculating until 1994.the setpoint allowable values in a number of the CY technical specificatio,ns are not valid. The invalid values include: RCS Low Flow Reactor Tri SteamLineBreakFlowReactorTrip,p[PSCRe/

Steam Feed V actor Flow Mismatch Reactor Hi Pressurizer LevelTrip, Reactor Trip HCP Reactor Trip PORV Actuation '

Trip,DelugeActuation,RHRValvePermiss,ive,NISPowerRan,gePermissive,f7&

Core P8 Permissives. ,

The present operations manager at CY suppressed these concerns for years by ignoring them when he was the plant instrumentation mana er. When I raised the concerns to him personally in a 1994 meeting, he sim ly claimed the setpoints were safe, and refused to discuss the reasons hey might be unsafe.

An automobile comparison would be like a town manager refusing to review speed limits to the latest safety standards. Assume a car stops 50 feet on dry pavement after you apply the brakes. If new safety information comes out that says you should leave an additional 25 feet for adverse road conditions and an additional 25 feet for the driver to react, then you should allow 50,+ 25 +

25 - 100 feet of stopping distance to be safe. The present CY allowable l values are based on 50 feet. CY should correct the technical specifications, and have NRC approval of the changes before they continue to operate.

The improper allowable values leads to the final safety concern. It is not 1 l l

l l

[

l t oossible to do pr per safety evaluations with improper allowable values. When Instrument error such sometimes found asthe o tside driftlim)its is checked durina calculated to 6e shutdown at CY safe, limits it is to r,eferred as the acceptance criteria. This is common at all olants and has happened hundreds of times at CY. The concern is when this happens at CY there is no l

method in olace to evaluate whether safety limits were violated,,and whether a setpoint change is needed to ensure safe operation in the future.

! assume the CY setpoints have been u I To uselatest to the the automobile safety standards,analogy and again,le ve 100 feet for the car to stop.pdated The procedures still say the brakes should stop the car in 50 feet which is fine.

Now assume when braking distance is checked, it is sometimes fo,und to be 80 feet. With the evaluation method at CY they wo "no since we If problem,d you nee 80 feet

! wehave20feettospare"uldsay: Wrong.

have 100 feet25tofeet stopfor road conditions and 25 feet for driver reaction, 80 +

for brakin g$0.

25 + 25 1 You now need 130 feet to stop safely.

What do I expect from the NRC7 I expect the concerns to be reviewed by the l and I expect to be contacted for more information.

NRC withtoexperts,ine the NRC determ in a few weeks whether the concerns are valid, andI expect i whether CY should resolve these concerns.  !

At the August 7th NRC public meeting in Waterford, I will listen for any progress made investigating these concerns.

Former CY Design Engineering .

cc: Paul Blanch, Greg Wingard CC: ERNIE HADLEY <ECHADLEY@aol.com>

i i

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