ML20210M779
| ML20210M779 | |
| Person / Time | |
|---|---|
| Site: | Perry  |
| Issue date: | 08/04/1999 |
| From: | Jeffery Wood CENTERIOR ENERGY |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| Shared Package | |
| ML20210M781 | List: |
| References | |
| PY-CEI-NRR-2418, NUDOCS 9908100177 | |
| Download: ML20210M779 (7) | |
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M K. M 44gggo.5gg4 Vice President. Nwdear py pygmy August 4,1999 PY-CEl/NRR-2418L United States Nuclear Regulatory Commission Document Control Desk Washington, D.C. 20555 1
Perry Nuclear Power Plant Docket No. 50-440 4 License Amendment Request Pursuant to 10CFR50.90: Revision of Required l Action for Technical Specification 3.9.1, " Refueling Equipment interlocks" Ladies and Gentlemen:
Nuclear Regulatory Commission review and approval of a license amendment for the Perry Nuclear Power Plant (PNPP) is requested. The amendment would incorporate an additional option into the Required Actions for Technical Specification 3.9.1," Refueling Equipment Interlocks". The change would provide additional Required Actions when the refueling interlocks are inoperable. The alternative is to block control rod withdrawal immediately, and to perform an additional verification that all of the control rods required to be inserted are fully inserted. This proposed change has been developed for implementation during the eighth refueling outage (RFO8).
This license amendment request replaces a previous submittal, which was withdrawn by letter dated March 10,1999 (PY-CEl/NRR-2368L). As noted in that letter, this new proposal is consistent with an NRC-approved Standard Technical Specification Change Traveler, Number TSTF-225. This change has also been approved for another BWR-6 plant, similar to PNPP.
Attachment 1 provides a Summary, System Description / Background, Description of the Proposed Technical Specification Change, Safety Analysis, and Environmental Consideration.
Attachment 2 provides the Significant Hazards Consideration. Attachment 3 provides the annotated Technical Specification page reflecting the proposed change. Attachment 4 provides an annotated Bases page, for information, since the Bases are not a formal part of the Technical Specifications.
There are no regulatory commitments contained in this letter or its attachments. If you have questions or require additional information, please contact Mr. Henry L. Hegrat, Manager - Regulatory Affairs, at (440) 280-5606.
Ve truly yours, f 1 Attachments fCD I
i cc: NRC Project Manager NRC Resident inspector NRC Region til State of Ohio 990ts100177 990004 PDR ADOCK 05000440 I P PDR ,
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' I,' John K. Wood, hereby afTirm that (1) I am Vice President - Perry, of the FirstEnergy Nuclear Operating Company, (2) I am duly authorized to execute and file this certification as the duly authorized agent for The Cleveland Electric Illuminating Company, Toledo Edison Company, Duquesne Light Company, Ohio Edison Company, (
and Pennsylvania Power Company, and (3) the statements set forth herein are true and I correct to the best ofmy knowledge, information and belief.
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Attachm:nt 1 PY-CEl/NRR-2418L Page 1 of 3
SUMMARY
The proposed change adds additional Required Actions to Technical Specification 3.9.1,
- Refueling Equipment Interlocks". The additional Required Actions provide an alternative action for when the refueling interlocks are inoperable. Basically, operable refueling interlocks permit fuel loading to proceed without the need to have a control rod withdrawal block in effect at all times, since the interlocks insert appropriate blocks if the need arises. The requested alternative for when the refueling interlocks are inoperable is to block control rod withdrawal immediately, and to perform an additional verification that all of the control rods required to be inserted are fully inserted. The proposed additional Required Actions provide an equivalent level of assurance that fuel will not be loaded into a core cell with a control rod withdrawn as do the current Required Action or the Surveillance Requirement.
The proposed Required Actions increase consistency within the Technical Specifications, since they are similar to the Required Actions for an existing, related Limiting Condition for Operation (LCO) 3.9.4, " Control Rod Position Indication". LCO 3.9.4 controls the operability of the control rod position indicators, which serve a support system role for the refueling interlocks controlled by LCO 3.9.1 (the position indicators provide information to the all-rods-in interlock). LCO 3.9.4 requires that when one or more control rods do not have the required position indication operable, that either all the insertable control rods be inserted and fuel movement and control rod withdrawal be suspended (Required Actions A.1.1, A.1.2 and A.1.3), g, that the associated control rod (s) be inserted and disarmed (Required Actions A.2.1 and A.2.2). The key is that if Required Actions A.2.1 and A.2.2 are complied with, then refueling activities can continue. The proposed LCO 3.9.1 Required Actions are consistent with the current Required Actions of LCO 3.9.4 in that they require either fuel movement be suspended (similar to the A.1 series of Actions), or that all control rods required to be inserted be verified to be inserted and that control rod v/ithdrawal be blocked (similar to the A.2 series of Actions).
This proposed change has been developed for implementation during the next refueling outage (Refuel Outage 8).
DESCRIPTION OF THE PROPOSED TECHNICAL SPECIFICATION CHANGE in Technical Specification 3.9.1, the existing Required Action A.1 will be revised to include an Option A.2, consisting of:
9.B A.2.1 Insert a control rod immediately withdrawal block AND A.2.2 Verify all control rods immediately are fully inserted in core cells containing one or more fuel assemblies.
[ Note: An annotated Bases page is contained in Attachment 4 "for information only". The Bases are not part of the Technical Specifications, and are not a formal part of this license
4 Att: chm:nt 1 PY-CEl/NRR-2418L Page 2 of 3 amendment package. The Bases are revised under the PNPP Bases Control Program (Technical Specification 5.5.11)]
SYSTEM DESCRIPTION / BACKGROUND
- The refueling equipment interlocks are described in the Bases for Technical Specification 3.9.1 and in the Updated Safety Analysis Report (USAR) Sections 7.7.1.6 and 9.1.4.2.7.
Refueling equipment interlocks restrict the operation of the refueling equipment or the withdrawal of control rods to reinforce unit procedures in preventing the reactor from achieving criticality during refueling. The refueling equipment interlock circuitry senses the conditions of the refueling equipment and the control rods. Depending on the sensed conditions, interlocks are actuated to prevent the operation of the refueling equipment or the withdrawal of control rods (rod block).
The control rods, when fully inserted, serve as the system capable of maintaining the reactor
- subcritical in cold conditions during all fuel movement activities and accidents, as required by General Design Criterion (GDC) 26 of 10CFR50, Appendix A.
The following provide input to one or both redundant channels of the interlock instrumentation:
- 1) the position of the refueling platform,2) the loading of the refueling platform main hoist, and
- 3) the full insertion of all control rods. During refueling operations, the indicated conditions are combined in logic circuits to determine if all restrictions on refueling equipment operations and control rod insertion are satisfied.
Criticality and, therefore, subsequent prompt reactivity excursions, are prevented during the loading of fuel, provided all control rods are fully inserted during the fuel loading (except for control rods removed under the specific administrative controls of LCO 3.10.6). The refueling equipment interlocks accomplish this by preventing loading fuel into the core with any control rod withdrawn, or by preventing withdrawal of a control rod from the core during fuel loading.
To prevent these criticality conditions from developing, the all-rods-in, the refueling platform position, and the refueling platform main hoist fuel loaded inputs are required to be OPERABLE. These inputs are combined in logic circuits that provide refueling equipment interlocks or control rod blocks to prevent operations that could result in criticality during refueling operations.
SAFETY ANALYSIS As discussed in the Bases for the current Required Action, the purpose of the current requirement (to suspend in-vessel fuel movement) is to ensure that operations are not performed with equipment that would potentially not be blocked from unacceptable operations (e.g., loading fuel into a cell with a control rod withdrawn). The method that the refueling equipment interlocks use to perform their function whenever fuel is being moved over or in the reactor vessel is to block control rod withdrawal. Conversely, when a control rod is withdrawn (except as allowed by LCO 3.10.6) the refueling interlocks prevent fuel from being moved over or in the vessel. Basically, operable refueling interlocks permit fuel loading to proceed without the need to have a control rod withdrawal block in effect at all times. The proposed change will allow the refueling interlocks to be inoperable and fuel movement to continue if a control rod withdrawal block is placed in effect, and all control rods required to be inserted are verified to be
Attachm@nt 1 l PY-CEl/NRR-2418L Page 3 of 3 fully inserted, thereby ensuring that fuel loading will not occur with a control rod inappropriately withdrawn.
As discussed above, the first refueling equipment interlock safety function is to block control rod withdrawal whenever fuel is being moved over or in the reactor vessel. The proposed alternative Required Actions will perform this function by requiring that a control rod block be placed in effect. The second refueling equipment interlock safety function is to prevent fuel from being loaded into the vessel when a control rod is withdrawn. This function will also continue to be pu ormed by the proposed alternate LCO 3.9.1 Required Actions. Required Action A.2.1 will require that a control rod block first be placed in effect, thereby ensuring that control rods are not subsequently inappropriately withdrawn. Following placement of the control rod withdrawal block in effect, Required Action A.2.2 will require that all control rods be verified to be fully inserted in core cells containing one or more fuel assemblies. This verification is in addition to the requirements to periodically verify control rod position in Surveillance Requirement (SR) 3.9.3.1 and SR 3.10.6.2. These proposed Required Actions will ensure that control rods are not withdrawn and cannot be inappropriately withdrawn, because an electrical or hydraulic block to control rod withdrawal will be in place. Like Required Action A.1, Action A.2.1 and A.2.2 will ensure that unacceptable operations are blocked (e.g., loading fuel into a cell with a control rod withdrawn).
Required Action A.2.2 is consistent with the current requirements of LCO 3.10.6.b. The requirement that control rods need only be inserted in core cells containing one or more fuel assemblies is to allow control rods to be withdrawn in accordance with LCO 3.10.6 while complying with these LCO 3.9.1 Required Actions.
ENVIRONMENTAL CONSIDERATION The proposed Technical Specification change request was evaluated against the criteria of 10CFR51.22 for environmental considerations. The proposed change does not significantly I increase individual or cumulative occupational radiation exposures, does not significantly change the types or significantly increase the amounts of effluents that may be released off-site and, as discussed in Attachment 2, does not involve a significant hazards consideration. Based i on the foregoing, it has been concluded that the proposed Technical Specification change meets the criteria given in 10CFR51.22(c)(9) for categorical exclusion from the requirement for an Environmental impact Statement.
Attachm nt2 PY-CEl/NRR-2418L Page 1 of 2 Sinnificant Hazards Consideration The standards used to arrive at a determination that a request for amendment does not involve a significant hazard are included in Commission regulation 10CFR50.92, which states that operation of the facility in accordance with the proposed changes would not:
- 1) involve a significant increase in the probability or consequences of an accident previously evaluated; or
- 2) create the possibility of a new or different kind of accident from any accide.nt previously evaluated; or
- 3) involve a significant reduction in a margin of safety.
The proposed amendment has been reviewed with respect to these three factors and it has been determined that the proposed change does not involve a significant hazard because:
- 1. The proposed change does not involve a significant increase in the probability or consequences of an accident previously evaluated.
The refueling interlocks are explicitly assumed in the PNPP Updated Safety Analysis Report (USAR) analyses of the control rod removal error and fuel loading error during refueling. This analysis evaluates the probability and consequences of control rod withdrawal during refueling. Criticality and, therefore, subsequent prompt reactivity excursions are prevented during the loading of fuel, provided all required control rods are fully inserted. The refueling interlocks accomplish this by preventing loading fuel into the core with any controi rod withdrawn, or by preventing withdrawal of a rod from the core during fuel loading. When the refueling interlocks are inoperable, the current method of preventing fuel loading when a control rod is withdrawn, is to prevent fuel movement. This method is currently required by the Technical Specifications. An alternate method to ensure that fuel is not loaded into a cell with the control rod withdrawn is to prevent control rods from being withdrawn and verify that all control rods required to be inserted are fully inserted. The proposed Technical Specification Required Actions will require that a control rod block be placed in effect, thereby
- ensuring that control rods are not subsequently inappropriately withdrawn. Additionally, following placing the control rod withdrawal block in effect, the proposed actions will require that all required control rods be verified to be fully inserted. This verification is in addition to the requirements to periodically verify control rod position by other Technical Specification requirements. These proposed actions will ensure that control j rods are not withdrawn and cannot be inappropriately withdrawn, because an electrical or hydiaulic block to control rod withdrawal is in place. Like the current requirements, the proposed actions will ensure that unacceptable operations are blocked (e.g.,
! ceding fuel into a cell with a control rod withdrawn, except when following the requirements of LCO 3.10.6, " Multiple Control Rod Removal-Refueling," which is unaffected by this change). The proposed additional Required Actions provide an equivalent level of assurance that fuel will not be loaded into a core cell with a control rod withdrawn as do the current Required Action or the Surveillance Requirement.
Therefore, the proposed change does not significantly increase the probability or consequences of an accident previously evaluated.
2 Attachm:nt 2 PY-CEl/NRR-2418L Page 2 of 2 Slanificant Hazards Consideration
- 2. The proposed change would not create the possibility of a new or different kind of accident from any accident previously evaluated.
The change in the Technical Specification requirements does not involve a change in plant design, or to the status of the reactor core during refueling. The proposed actions will ensure that control rods are not withdrawn and cannot be inappropriately withdrawn, because an electrical or hydraulic block to control rod withdrawal is in place.
Although the exact method by which the control rod withdrawal block is inserted is revised, the net effect is equivalent. The requirements will continue to ensure that fuel is not loaded into the core when a control rod is withdrawn, except when following the requirements of LCO 3.10.6, " Multiple Control Rod Removal-Refueling," which is unaffected by this change. Therefore, no new failure modes are introduced, and the proposed changes do not create the possibility of a new or different kind of accident from any accident previously evaluated.
- 3. The proposed change will not involve a significant reduction in the margin of safety.
As discussed in the Bases for the affected Technical Specification requirements, inadvertent criticality is prevented during the loading of fuel provided all required control rods are fully inserted during the fuel insertion. The refueling interlocks function to support the refueling procedures by preventing control rod withdrawal during fuel movement and the inadvertent loading of fuel when a control rod is withdrawn. The proposed change will allow the refueling interlocks to be inoperable and fuel movement to continue only if a control rod withdrawal block is in effect and all required control rods are verified to be fully inserted. These proposed Required Actions provide an equivalent level of protection as the refueling interlocks by preventing a configuration which could lead to an inadvertent criticality event. The refueling procedures will continue to be supported by the proposed Required Actions because control rods cannot be withdrawn and as a result fuel cannot be inadvertently loaded when a control rod is withdrawn, except when following the requirements of LCO 3.10.6, " Multiple Control Rod Removal-Refueling," which is unaffected by this change. Therefore, the proposed changes do not cause a significant reduction in the margin of safety.
Based on the above considerations, it is concluded that a significant hazard would not be introduced as a result of this proposed change. Also, since NRC approval of this change must be obtained prior to implementation, no unreviewed safety question can exist.