ML20195D893

Requests Assistance Re Technical Issue Limitations of Removing Normal Control Rod System Controls from Service on Operating Reactor (TIA 98-008)

ML20195D893
Person / Time
Site:	Duane Arnold
Issue date:	06/18/1998
From:	Grobe J NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III)
To:	Adensam E NRC (Affiliation Not Assigned)
Shared Package
ML20195D880	List: ML20195D878 ML20195D893
References
NUDOCS 9811180190
Download: ML20195D893 (3)

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1. M8 24 UNITED STATES

1. %, NUCLEAR REGULATORY COMMISSION

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• t 801 WARRENv!LLE ROAD f lisle. ILLINots 60532-4351 p ,33l O o5 June 18, 1998 MEMORANDUM TO: Elinor Adensam, Acting Director, Division of Reactor Projects, NR FROM:

A. Grobe, Director, Division of Reactor Safety, Region lll

SUBJECT:

REOUEST FOR ASSISTANCE - TECHNICAL ISSUE LIMITATIONS OF REMOVING NORMAL CONTROL ROD ,

SYSTEM CONTROLS FROM SERVICE ON AN OPERATING j

REACTOR (TIA 98-008)

During two recent events in Region lil, licensee personnel at Duane Amold and Palisades intentionally disabled normal rod control systems with the reactors operating at power. These two issues have raised a generic concem on licensees disabling the rod control systems at power.

A review of Technical Specification and FSAR documentation can lead one to infer that the expected plant configuration will be that manual control rod operation is available. Since this item is not specifically addressed by Technical Specifications, there is not a defined period of l time that the rod control systems can be out of service. In addition, most FSARs bound their accident scenarios by reactor protection system actuation of a full reactor trip. The ability to trip the reactor is not compromised by removing the rod control system from service.

l At Duane Amold an additionalissue conceming the applicability of 10 CFR 50.59 to voluntary removal of rod control from service was identified. This was discussed at a 50.59 screening panel on April 2,1998, but no decision was made as to the requirements under 10 CFR 50.59.

Subsequent to that screening meeting, further discussions showed that 10 CFR 50.59 is not applicable to maintenance activities.

Region ill is concerned with the practice of removing rod control systems from service at power and requests assistance in establishing a generic regulatory position on the period of time and under what circumstances it is acceptable to remove rod control from service.

i CONTACT: M. Leach, DRS (630)829-9705 i

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9811180190 981112 )

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E. Adensam 2 A response is requested by December 31,1998.

Some background information on Palisades and Duane Amold which may be of assistance is 4 attached.

Attachment:

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• Palisades ,

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Palisades existing Technical Specifications contain the following wording

A CONTROL ROD is considered inoperable if it cannot be moved by its operator or ....." As documented by inspection report 97014, the licensee tagged out all of the control rods at 80% power without realizing that this Technical Specification applied. It is interesting to note that this wording is somewhat unique as compared with the other PWR's in Region Ill.

Palisades is currently in the middle of a Technical Specification upgrade project scheduled to be complete sometime in 1999. A review of the CEOG STS finds that there are no similar words

. to the wording that currently exists in the Palisades Technical Specifications. The CEOG STS 3

do contain two significant items. First, a surveillance exists for moving each Control Element i

Assembly (CEA) at least five inches every 92 days to ensure operability. This implies that the CEA's can be moved manually. Second, inoperability of the CEA motion inhibit logic results in a REQUIRED ACTION that includes an action to: " Place and maintain the CEA drive switch in either the "off" or " manual" position, ...." This statement, which does not imply a limit on duration, implies that there is nothing wrong with not having the ability to move the CEAs. The Bases for this action states that: " Placing the CEA drive switch in the "off' or " manual" position ensures the CEAs will not move in response to Reactor Regulating System automatic motion commands."

l A review of Palisades FSAR indicates that the Chapter 14 accident analyses rely purely on the reactor trip system and poison addition (boron) to mitigate any transients. This assumption is used as the bounding analysis for any event that adds positive reactivity. However, there are other sections of the Palisades FSAR that discuss use of the rod control system to mitigate l transients.

Duane Amold Duane Amold's Technical Specifications do not directly state that the rod control system has to be operable. Indirectly, Technical Specification 3.3.d implies that the operators will have the ability to perform actions to recouple an uncoupled control rod and to perform coupling checks on control rods when they reach the fully withdrawn position. Technical Specification surveillance requirement 4.3.f(l) further implies that the rod control system will be operable since there is a requirement to exercise each fully withdrawn control rod once per week.

A review of Duane Amold FSAR indicates that the Chapter 14 accident analyses rely purely on the reactor trip system to mitigate any transients. This assumption is used as the bounding analysis for any event that adds positive reactivity. However, there are other sections of the Duane Arnold FSAR that discuss use of the rod control system to mitigate transients, including use of the rod control system to mitigate transients in order to meet Safety Design Bases and control reactor power and power distribution limits.

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