ML20245A815

Responds to 890515 Request for Info Re 880412 RCIC Sys Event.Augmented Insp Team Concluded That Transient Minor Since Several Barriers Remained Intact to Mitigate Effects of Potential Intersystem Loss of Coolant

ML20245A815
Person / Time
Site:	Pilgrim
Issue date:	06/14/1989
From:	Blough A NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I)
To:	Dinan M AFFILIATION NOT ASSIGNED
Shared Package
ML20245A818	List: ML20245A815 ML20245A846
References
NUDOCS 8906220198
Download: ML20245A815 (4)

Text

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JUN 14 7939 Ms. Mary Dinan 15 Jeremiah Drive Duxbury, Massachusetts 02332

Dear Ms. Dinan:

I am responding to the letter of May 15, 1989, to Mr. William Kane, Director, Division of Reactor Projects from you, Ms. Jane Fleming and Ms. Kate O'Brien.

In that letter you requested detailed information, primarily concerning an April 12, 1989, event at the Pilgrim Station involving the reactor core isola-tion cooling (RCIC) system. Much of the information requested is contained in U NRC Augmented Inspection Team (AIT) Report Number 50-293/89-80, available in -

your Local Public Document Room (LPDR). A copy of the AIT report is enclosed for your convenience. I believe a careful review of this document will answer many of your questions. Since the information contained is substantial in volume and technical in nature, I will attempt to provide a brief summary in response to each of your six areas of interest.

1. Classification of the Event The licensee's emergency plan contains the criteria used to determine if a plant event warrants notification of offsite agencies and the appropriate level of onsite response. The April 12, 1989, event during which the RCIC system pump suction piping was pressurized did not meet the significance threshold which would require declaration of an Unusual Event, the lowest level of emergency plan event classification. This determination was sup-ported by the licensee's analysis at the time of the event, and was subse-quently confirmed by the NRC AIT. As a conservative measure the licensee maintains an internal notification procedure encompassing events of minor significance not requiring classification by the emergency plan, but of potential interest to licensee management, the NRC and other parties. In this instance the licensee determined that notification in accordance with their internal procedure was warranted, categorized the transient as an "Off-Normal" event, and implemented the planned notifications. No decla-ration was required by the licensee's emergency plan in this case. A complete description of this area is included in NRC AIT Report, Section 9.6.

2. Licensed Operator Shift Staffing and Qualifications, and Plant Technical Staff Qualifications The attached NRC AIT report includes a complete description of the relevant aspects of this event and a detailed chronology. The number of licensed operators on shift and in the control room before, during and following the event was evaluated and found to be acceptable. The names and license numbers of the individuals involved is not germane to understanding of the event.

OFFICIAL RECORD COPY LYASH 521 6/10/89 - 0001.0.0 06/14/89 (h

u' 8906220190 090614 PDR ADOCK 05000293 H PDR  !

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Ms. Mary Dinan. 2 JUN 141989 The NRC has established minimum education and experience requirements for licensed operators, as well as other members of the plant technical staff.

These requirements are used to screen operator license candidates prior to administration of any license exam. The qualifications and training of the plant technical staff are routinely evaluated as part of the ongoing 1

NRC inspection program. The level of experience and training of the licensed operators at Pilgrim was extensively reviewed during the NRC Integrated Assessment Team Inspection (IATI) prior to authorizing plant restart. This review is documented in NRC Inspection Report 50-293/88-21 and noted that the experience of the Pilgrim operating staff constitutes a significant strength. Specific aspects of personnel training which could have contributed to the subject event were also reviewed during the recent AIT and are discussed in the report.

3. Relative Significance of the Event, the Occurrence of Past Similar Events, and the Probability of Reactor Accidents in General The NRC AIT concluded that this transient was minor since several barriers remained intact to mitigate the effects of a potential intersystem loss of coolant. The Team also concluded that the event did not constitute an accident precursor. '

As described in the AIT report one similar occurrence involving the high pressure coolant injection system occurred at Pilgrim during 1983. This event was evaluated in 1983, and was revisite.d by the recent AIT to assess the applicability of past corrective actions to the recent problem.

) Potential accident sequences and their relative probabilities have been the subject of extensive NRC and industry study. This large volume of information has been used to draw generic insights regarding accident probability. In addition, many licensees have initiated plant-specific probabilistic risk studies and utilized the results to improve individual plant designs and operating practices. Boston Edison has implemented a plant-specific study which considers existing industry experience and data, as well as the Pilgrim plant design and operating history. This analysis indicates that the probability of a significant accident occurring at Pilgrim is extremely low.

OFFICIAL RECORD COPY LYASH 521 6/10/89 - 0002.0.0 06/10/89 L__-__-_-. _

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Ms Mary ~ Dinan 3 JUN 141989

4. Contamination of the RCIC Pump Room as a Result of the Steam Released to the Room Ouring the Transient During the transient water was discharged from the RCIC system into the surrounding ~ area of the reactor building. Upon discharge some. of the water flashed to steam. The source of the water is the main feedwater i

" system, . and as a ' result both the water and the steam would contain some

-radioactive contaminants. Release of the fluid resulted in contamination of the general area and a brief. period during which airborne contamination was. present. While this is ~ not a desirable circumstance, the reactor 4 building is designed to tolerate leaks such as this without any resultant -

release to the environment. Plant personnel are trained to deal with con-ditions that include potential airborne contamination, and are monitored to ensure that protective measures have prev 2nted any significant inhala- 'y tion of contamination. /

5. Steam Noted by a Local Citizen Emminating from the Pilgrim Plant on May 10, 1989 The design of a boilir,g water reactor such as Pilgrim does not include provisions which would allow the release of nuclear steam to the environ-ment during normal ' operations. During the time period in question the plant remained in cold shutdown, so no nuclear steam was being generated.

There are two small oil fueled boilers used for heating buildings, and several. diesel generators located onsite. It is possible that the individual you reference may have noted steam or exhaust emissions from s one of these sources.

, 6. Security Planning for the Pilgrim Site The NRC rs; quires that each licensee. maintain and implement a security plan. . -This includes a contingency plan designed to provide for security force response to potential threats. While restrictions governing the control of safeguards information prohibit any detailed discussions in this letter, these plans do include measures addressing external assault. The Code of Federal Regulations, Title 10, Part 73 outlines the regulatory requirements and performance standards used to evaluate the adequacy of licensee security plans.

OFFICIAL RECORD COPY LYASH 521 6/10/89 - 0003.0.0 06/14/89

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Ms. Mary Dinan 4 JUN 141989 Please review the attached AIT report, I believe it will answer many of your questions. Other reports, such as the referenced IATI report, are also readily available in the LPDR. If significant questions remain after reviewing this document, please contact me via telephone at (215) 337-5146. I hope this has been responsive to your request.

Sincerely.

Orsts -,, ,, oy A. Randy bough A. Randy Blough, Chief Reactor Projects Section No. 3B Division of Reactor Projects

Attachment:

As stated cc w/o Attachment (but w/ Incoming Letter):

Public Document Room (PDR)

Local Public Document Room (LPDR)

Chairman, Board of Selectmen, Duxbury Chairman, Board of Selectmen, Plymouth Chairman, Board of Selectmen, Carver Chairman, Board of Selectmen, Marshfield Chairman, Board of Selectmen, Kingston Chairman, Board of Selectmen, Bridgewater Mayor, City of Taunton R. Bird, Senior Vice President - Nuclear, Boston Edison Company P. Agnes, Assistant Secretary of Public Safety, Commonwealth of Massachusetts bec w/o Attachment (but w/ Incoming Letter):

S. J. Collins, DRP J. T. Wiggins, DRP J. J. Lyash, DRP M. J. DiDonato, DRP (DRP RA File)

C. C. Warren, SRI - Pilgrim J. P. Holmes, (RA Action Item 89-91)

Q RI:DRP JLyash/mjd RI:DRP RBlough RI:DRP JWiggins

DRP ollins 6/P/89 6//2/89 6/h'89 6/Q/89 0FFICIAL RECORD CDPY LYASH 521 6/10/89 - 0004.0.0 06/13/89

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