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Forwards Summary of Enforcement Conference on 880421 Re Findings Concerning Incore Detector Maint Radiation Exposure Event on 880303 & Corrective Actions in Response to Insp Repts 50-280/88-10 & 50-281/88-10.Related Info Encl
	ML18152A285
Person / Time
Site:	Surry
Issue date:	05/03/1988
From:	Grace J; NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II)
To:	Cruden D; VIRGINIA POWER (VIRGINIA ELECTRIC & POWER CO.)
References
	NUDOCS 8805100186
	Download: ML18152A285 (46)
	v • d • e

Docket Nos. 50-280, 50-281

License Nos. DPR-32, DPR-37

MAV O 3 \\988

Virginia Electric and Power Company

ATTN:

Mr. D. S. Cruden, V"ice President,

Nuclear Operations

P. 0. Box 26666

Richmond, VA

23261

Gentlemen:

SUBJECT:

ENFORCEMENT CONFERENCE SUMMARY

(NRC INSPECTION REPORT NOS. 50-280/88-10 AND 50-281/88-10)

off; t I 8)

This 1 etter refers to the Enforcement Conference held at our request on

April 21, 1988.

This meeting concerned activities authorized for your Surry

facility.

The issues discussed at this conference related to the findings of

the investigative task force formed to review the incore detector maintenance

radiation exposure event of March 3, 1988, and the subsequent corrective

actions in response to Inspection Report Nos. 50-280/88-10 and 50-281/88-10.

A

summary, a list of attendees, and a copy of your handout are enclosed .

It is our opinion that this meeting was beneficial and has provided a better

understanding of the inspection findings, the enforcement issues, and the

status of your corrective actions.

We are continuing our review of these

issues to determine the appropriate enforcement action.

In accordance with Section 2.790 of the NRC

1s

11Rules of Practice,

11 Part 2,

Title 10, Code of Federal Regulations, a copy of this letter and its enclosures

will be placed in the NRC Public Document Room.

Should you have any questions concerning this matter, please contact us.

Enclosures:

1.

Enforcement Conference Summary

2.

List of Attendees

3.

Handout

cc w/encls:

(See page 2)

Sincerely,

J. Nelson Grace

Regional Administrator

8805100186 880503

PDR

ADOCK 05000280

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DCD

J:.fOi

Virginia Electric and Power Company

2

cc w/encls:

D. L. Benson, Station Manager

N. E. Hardwick, Manager - Nuclear

Programs and Licensing

bee w/encls:

NRC Resident Inspector

DRS Technical Assistant

Document Control Desk

J. Lieberman, DOE

G. Jenkins, EICS

Commonwealth of Virginia

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ENCLOSURE 1

Enforcement Conference Summary

Licensee:

Virginia Electric and Power Company

Facility:

Surry

Docket Nos.:

50-280, 50-281

License Nos.:

DPR-32, DPR-37

Subject:

Corrective Actions Regarding Inspection Report Nos. 50-280/88-10 and

50-281/88-10 and Findings of the Investigative Task Force Formed to

Review the Incore Detector Maintenance Radiation Exposure Event

An Enforcement Conference was held at the Region II office on April 21, 1988,

to discuss the findings identified in Inspection Report Nos. 50-280/88-10 and

50-281/88-10 and the results of the licensee's investigation of the incident

and review the corrective actions taken as a result .

Licensee representatives discussed the sequence of events surrounding the

incore detector exposure incident of March 3, 1988.

A summary of the licensee's

investigative team findings was presented including calculated estimates of the

whole body and extremity doses received by each of the three individuals

involved.

Whole body doses ranged from 707 to 1,033 millirem and extremity

doses from 996 to 1,267 millirem.

The licensee presented the basis for their

calculations, their assessment of the root cause of the problem and their short

and long term corrective actions.

The lack of awareness on the part of licensee

personnel involved that the detector drive cable could become activated and

cause high radiation levels was identified as the root cause.

NRC representatives discussed the breakdown of the licensee's system, including -

management review, which had been implemented to prevent such occurrences.

Other items discussed included an apparent lack of procedural compliance on the

part of the workers, adequacy of the procedure used to free the detector, and

the licensee determination of the actual root cause of the problem.

The

Regional Administrator made the point that it was fortuitous that apparently no

exposures in excess of NRC limits had occurred .

\\ .. I

ENCLOSURE 2

Enforcement Conference Attendees

Virginia Electric and Power Company

W. Bartlett, Senior Staff Health Physicist, Corporate

R. Berryman, Manager, Nuclear Analysis and Fuel, Corporate

D. Cruden, Vice President, Nuclear

E. Grecheck, Assistant Station Manager, Surry

N. Hardwick, Manager, Nuclear Power and Licensing, Corporate

J. Hegner, System Engineer, Corporate

G. Pannell, Director, SEC

S. Sarver, Superintendent, Health Physics, Surry

R. Thomas, Senior Staff Engineer, Corporate

F. Thomasson, Supervisor, Health Physics, Corporate

Nuclear Regulatory Commission

C. Bassett, Radiation Specialist, Division of Radiation Safety and Safeguards

(DRSS)

F. Cantrell, Section Chief, Division of Reactor Projects (DRP)

D. Collins, Branch Chief, DRSS

0. DeMiranda, Enforcement Specialist, Enforcement and Investigation

Coordination Staff (EICS)

J. Grace, Regional Administrator

C. Hehl, Deputy Director, DRP

W. Holland, Senior Resident Inspector, Surry

C. Hosey, Section Chief, DRSS

G. Jenkins, Director, EICS

T. MacArthur~*Reactor Inspector, Technical Support Staff (TSS)

C. Patel, Project Manager, Surry, Office of Nuclear Reactor Regulation (NRR)

W. Rankin, Technical Assistant, DRSS

M. Scott, Project Engineer, DRP

L. Slack, Enforcement Specialist, EICS

B. Wilson, Branch Chief, DRP

INCORE DETECTOR MAINTENANCE

RADIATION EXPOSURE EVENT

NRCENFORCEMENTCONFERENCE

APRIL 21, 1988

/

\\

""

R.M. BERRYMAN

Manager

Investigative Task Force

-~

I

!

@LIDJJ~©lFOW~ @[p [f)[ru~~~[N]lf £ 1r0@[NJ

DEMONSTRATE THE SEQUENCE OF EVENTS

BY PRESENTING A VIDEOTAPE REENACTMENT

SUMMARIZE INVESTIGATION FINDINGS

IDENTIFY CORRECTIVE ACTIONS

MEASURES NEUTRON FLUX DISTRIBUTION AT

SELECTED LOCATIONS WITHIN REACTOR CORE

FIVE MOVABLE DETECTORS ARE AVAILABLE TO

SCAN THE LENGTH OF FIFTY SELECTED FUEL

ASSEMBLIES

Reactor

Vessel

Seal

Table

5-Path

Transfer Devices

t

10-Path

Transfer Devices

l

Limit

Switch

i

Crane

Wall

Containment

Wall~

Drive

Box

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Crane Wall~

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Transfer Davie

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.* .. * . *.*.*. . -:*

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-

CM.IIIIA TIIJH TUI£

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Drive Units

, ~Motor Stop Limit s witch

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Inserted/Withdrawn Limit

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Switch

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10-Path

Transfer Devices

k-1

Concrete

Storage

Area

IN-CORE NEUTRON

DETECTION SUBSYSTEM

I .

FISSION

CHAMBER

.........

' " \\ *

l'ELEFLEX

I

CABLE~

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. . I

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/

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Fission Chamber and Drive Cable Schematic

HARO LINE

CABLE

MICRODOT

CONNECTOR

-.. -- -----------

STORAGE

LOCATI~

1

06 ;;i..

o oO v

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10-Path

Transfer Devices

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VESSEL SEAL LINE

D"IVE MECHANISM

THUIMOCOUl'LI CONDUIT

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SUPPORT

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THEAMOCOI.WLI CONDUIT

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VESSEL 'ENETflATION

TUH

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THIMBLE GUIDE-*

TUBE W!L.D

UNION

Elevation View - Incore Detector Drive System

FEB 8, 1988

"A" INCORE DETECTOR STUCK

MARCH 3, 1988

CONTAINMENT ENTRY TO FREE AND REPLACE DETECTOR

(2 INST. TECHS. AND 1 HP TECH)

DETECTOR MANUALLY WITHDRAWN WHEN ATTEMPT

TO DRIVE ELECTRICALLY FAILED

WORK TERMINATED BY HP TECH WHEN HIGH RADIATION

LEVELS WERE DETECTED

MARCH 8,.1988

EVALUATIONS IDENTIFY THE PRIMARY SOURCE

. OF RADIATION TO BE ACTIVATED CABLE

MARCH 9, 1988

RECOVERY ACTIONS COMPLETED

MARCH 11, 1988

INVESTIGATION TASK FORCE APPOINTED

..

."

..

SOURCE OF RADIATION IN WORK AREA

WHOLE BODY AND EXTREMITY RADIATION DOSES

ROOT CAUSE OF THE EVENT

OTHER CAUSAL FACTORS LEADING TO

THE OCCURRENCE

-~

PRIMARY SOURCE OF RADIATION WAS THE CARBON STEEL DRIVE

CABLE WHICH HAD BECOME HIGHLY ACTIVATED

"A" DETECTOR WAS STUCK IN CORE LOCATION J5 APPROXIMATELY

55 INCHES INTO THE ACTIVE FUEL REGION FOR 26 DAYS

CAUSE OF THE STUCK DETECTOR WAS MISALIGNMENT OF THE

"B" TEN PATH TRANSFER DEVICE

RESULTS OF SURVEY MEASUREMENTS WERE USED TO ESTABLISH

THE FINAL POSITION OF THE DETECTOR AND ACTIVATED CABLE

.... . ..

. . . . .

.

. . ...

. .

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.,

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/l"/11

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W. T. Bartlett, Ph.D

RADIATION DOSE ASSESSMENT

MEDICAL EXAMINATION AND FOLLOWUP

DETERMINE WHOLE BODY AND EXTREMITY DOSES

WORST CASE SCENARIOS

EXPERT REVIEW

NON - UNIFORM EXPOSURE

TLD AND SRD NON - CONSERVATIVE

* EXTREMITY DOSE

)

' .*.

POTENTIAL CONT ACT WITH ACTIVATED CABLE

ISOTOPE OF CONCERN: Mn - 56 -

SKIN REACTIONS

BETA ATTENU.ATION

MAX RANGE MN-56 BETAs

ERVTHEMA THRESHOLD

2

112 MG/CM

1400 MG/CM 2

150~400 RAD

COMPANY PHYSICIAN ( MARCH 10, 1988)

- HISTORY/BIOLOGICAL SYSTEMS

- PHYSICAL EXAM {HANDS)

- LABORATORY

- NO EVIDENCE OF RADIATION INJURY

.FOLLOWUP

- PERIODIC VISUAL EXAM (3 WEEKS)

- BLOOD ANAL VSES

ASYMPTOMATIC

VERIFIED BY INTERVIEW

NO EVIDENCE OF CABLE CONTACT

' .*

BASED ON MOCKUP REENACTME*NT, POSITIONING

OF PERSONNEL WAS ESTABLISHED

SOU.ACE POSITION AND ACTIVITY

RELATE SURVEY MEASUREMENTS

,-

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RAO l AT ION

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.

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Crane f

Wall

Driv1

its

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,.

Relative Positions of Individuals During Incident

Five Path

Transfer

Device

Crane Wall _/

Take up Reel -1'

Activated portion of cable is shown by the hash marks

..

HP Technician

Technician No. 1

Technician No. 2

Knee * 18 inches

Shin

13 inches

UpperArm

17inches

Forearm

17 inches

Knee . 23 inches

Shin

20 inches

*

-~

.

MOVING LINE SOURCE

RATE OF MOVING

TUBE CASING

Mn-56 DOMINANT ISOTOPE (208 Ci)

DETECTOR (16.6 Ci)

55 INCH LENGTH

I

.

I

-

LINE SOURCE EQUATION

INTEGRAL OF VELOCITY {Chabot)

NUMERICAL ANAL VSIS (VP)

RATIO TLD TO BODY PARTS

1388

I

Unshielded Cable

mR/sec

12 inches

I

1388

Shielded Cable

mR/sec

12 inches

I

Whole Body Dose

SRD

Measured Calculated

HP Technician

240

707

Tech. No. 1

538

347

958

Tech. No. 2 *

555

1033

Extremity

Calculated

1217

996

1267

.

*

*

CONSISTENT WITH SOURCE ACTIVITY

FINAL CABLE POSITION IN DRIVE BOX

207 Ci Mn-56 CIRCULAR SOURCE

Dose Rate

255 mR/sec 170 mR/sec

73 mR/sec

Distance

1 Foot

2 Feet*

3 Feet

. * . *~

NO SIGNIFICANT HAND DOSE *

NO QUARTERL V LIMITS EXCEEDED

UNIQUE SOURCE & GEOMETRY FOR DOSIMETRY

MEASUREMENTS

EXPERT CONCURRENCE

. '.

R.M.BERRYMAN

Manager

Investigative Task Force

.*

.

w

PERSONNEL WERE UNAWARE OF THE POTENTIAL

THAT THE DRIVE CABLE COULD BE HIGHLY

RADIOACTIVE

LACK OF AWARENESS ATTRIBUTED TO:

P.REVIOUS EXPERIENCE WITH DETECTOR REPLACEMENTS

NOT INCLUDED IN TRAINING (NO GENERIC INDUSTRY

INFORMATION HAD IDENTIFIED THE PROBLEM)

INADEQUATE HEALTH PHYSICS INVOLVEMENT IN PRE-JOB PLANNING

-- HEAL TH PHYSICS PERSONNEL NOT INCLUDED IN PRE-JOB

BRIEFING HELD BY INSTRUMENT DEPARTMENT

INSTRUMENT DEPARTMENT CONTINUED WORK ONCE UNANTICIPATED

CONDITIONS DEVELOPED

--

ACTION TAKEN TO FULLY WITHDRAW THE DETECTOR BY HAND

WAS NOT INCLUDED IN THE APPROVED PROCEDURE

--

HEALTH PHYSICS WAS NOT MADE AWARE OF THE ACTION TAKEN

I,,

E. S. GRECHECK

ASSISTANT STATION MANAGER

SURRY POWER STATION

..

. (Implementation Dates)

INFORM NUCLEAR INDUSTRY AND APPROPRIATE STATION

PERSONNEL OF THE HIGH DOSE RATES POSSIBLE FROM AN

INCORE DETECTOR AND ACTIVATED DRIVE CABLE

INITIAL NETWORK ENTRY (Completed)

FINAL TASK FORCE REPORT (April 1988)

. FINAL NETWORK ENTRY (May 1988)

INPO RADIATION PROTECTION WORKSHOP (June 1988)

DISTRIBUTE TRAINING VIDEOTAPE TO INDUSTRY (June 1988)

'r

(Implementation Oates)

MODIFY APPROPRIATE TRAINING PROGRAMS TO INCLUDE

LESSONS LEARNED

*DETERMINE ENHANCEMENTS AND DEVELOP

. * ACTION PLAN TO REVISE INSTRUMENT *

AND HEAL TH PHYSICS TECHNICIAN TRAINING

. PROGRAMS (May 1988)

.

' .

0lf>>

(Implementation Dates)

MODIFY PROCEDURES USED TO OPERATE OR MAINTAIN THE

INCORE DETECTOR SYSTEM TO INCLUDE ADEQUATE PRECAUTIONS

AND INSTRUCTIONS WITH REGARD TO IRRADIATED DETECTORS

AND DRIVE CABLE

SNSOC PRE-APPROVAL OF INCORE DETECTOR

. * SYSTEM MAINTENANCE ACTIVITIES (Completed)

REVISE MAINTENANCE PROCEDURES (July 1988)

i

0tf>>

(Implementation Dates)

EMPHASIZE THE IMPORTANCE OF STOPPING WORK AND

EVALUATING THE SITUATION WHENEVER UNANTICIPATED

CONDITIONS ARISE (Completed)

ENHANCE HEAL TH PHYSICS INVOLVEMENT IN WORK PLANNING

INCREASE CONTROLS REGARDING SUBATMOSPHERIC

CONTAINMENT ENTRIES (Completed)

NO EXPOSURE If~ EXCESS OF REGULATORY

LIMITS OCCURRED

THE POTENTIAL FOR AN EXPOSURE IN EXCESS OF

REGULATORY LIMITS WAS LIMITED BY:

CONSERVATIVE ACTIONS BY THE INSTRUMENT TECHNICIANS

TIMELY RESPONSE BY THE HEAL TH PHYSICS TECHNICIAN

PRE-JOB ACTIVITIES CAN AND WILL BE IMPROVED

INFORMATION REGARDING THIS TYPE OF EVENT

WILL BE DISSEMINATED THROUGHOUT INDUSTRY

-

.

'*

,. *

ML18152A285

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