ML18068A300

Responds to NRC 980121 Ltr Re Violations Noted in Insp Rept 50-255/97-13.Corrective Actions:Training on Effects of Stratification in SG on Pcs Temperature Was Provided to Licensed Operators

ML18068A300
Person / Time
Site:	Palisades
Issue date:	02/27/1998
From:	Rogers D CONSUMERS ENERGY CO. (FORMERLY CONSUMERS POWER CO.)
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
50-255-97-13, NUDOCS 9803060419
Download: ML18068A300 (7)

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Consumers Energy>

• A CMS Energy Company Palisades Nuclear Plant 27780 Blue Star Memorial Highway Covert, Ml 49043 Da11/d llt Rogers General Manager - Plant Operations February 27, 1998 U.S. Nuclear Regulatory Commission ATIN: Document Control Desk Washington, DC 20555 DOCKET 50-255 - LICENSE DPR PALISADES PLANT REPLY TO NOTICE OF VIOLATION DESCRIBED IN INSPECTION REPORT NO. 50-255/97013 NRC Inspection Report No. 50-255/97013 dated January 21, 1998, contains a Notice of Violation (NOV) concerning an inadequate procedure which allowed operators to start a primary coolant pump without meeting Technical Specification requirements. The Consumers Energy Company reply to the violation is included in the Attachment to this letter.

The reply to the violation was requested to be submitted within 30 days from the date of the letter transmitting the violation. Discussion with Bruce Burgess (NRC Region Ill) on l' l

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January 28, 1998, confirmed that the 30-day requested response could be provided * .!

f within 30 days of receipt of the letter, which was January 28, 1998.

Consumers Energy Company agrees with the violation as written.

An additional concern regarding the Technical Specification aspects of the event and the lack of a questioning attitude by the operators was expressed in the cover letter for the insp~911Q!1 repor:t. Jha_t concern will be addressed in more detail in a separate submittal.

9803060419 980227 PDR ADOCK 05000255 G PDR 1111111111111111111111111111111111111111

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SUMMARY

OF COMMITMENTS This letter contains one commitment. This commitment is a restatement of the

. commitment made previously in Licensee Event Report 97-011, submitted on November 11 , 1997. That commitment is:

• System Operating Procedure SOP-1 will be revised to clarify requirements for starting primary coolant pumps when the PCS is solid. This revision will be made prior to the next use of the procedure for this purpose.

David W. Rogers Plant General Manager CC Administrator, Region Ill, USNRC Project Manager, NRR, USNRC NRC Resident Inspector - Palisades Attachment

. - ATTACHMENT CONSUMERS ENERGY COMPANY PALISADES PLANT DOCKET 50-255 REPLY TO NOTICE OF VIOLATION NO. 50-255/97013-01 (DRP) 4 Pages

ATTACHMENT

• REPLY TO NOTICE OF VIOLATION NO. 50-255/97013-01 (DRP)

NRC NOTICE OF VIOLATION During an NRG inspection from October 18 through December 5, 1997, one violation of NRG requirements was identified. In accordance with the "General Statement of Policy and Procedure for NRG Enforcement Actions", NUREG 1600, the violation is listed below:

10 CFR Part 50, Appendix 8, Criterion V, "Instructions, Procedures, and Drawings," requires, in part, that activities affecting quality shall be prescribed by documented instructions, procedures, or drawings of a type appropriate to the circumstances and shall be accomplished in accordance with these instructions, procedures, or drawings.

Contrary to the above, on October 12, 1997, the operations shift started the first primary coolant pump, using System Operating Procedure (SOP)-1, Revision 38, Step 4.3.1.(c)2, a procedure inappropriate to the circumstances in that it allowed using shutdown cooling return temperature (when shutdown cooling is operating), instead of Tccld* which resulted in the operators exceeding the Technical Specifications Tcold primary coolant pump start temperature limits.

This is a Severity Level IV violation (Supplement/).

CONSUMERS ENERGY COMPANY RESPONSE Consumers Energy agrees with this violation as 'written.

Background

On October 12 1997, plant heatup from a short maintenance outage was in progress.

At approximately 1926 hours0.0223 days <br />0.535 hours <br />0.00318 weeks <br />7.32843e-4 months <br />, with the plant at 250 psia and 130°F, plant prerequisites and checklists had been completed and Primary Coolant Pump (PCP) P-500 was started. Immediately following the pump start, the Primary Coolant System (PCS) pressure started to rise. Anticipating the PCS pressure rise, operators took manual action and limited the pressure to approximately 280 psia. A Low Temperature Overpressure Protection (LTOP) actuation did not occur since the LTOP setpoint at the prevailing PCS temperature was approximately 31 O psia. Because PCS pressure rose to this extent in a solid PCS, it was apparent that heat had been transferred from the steam generator secondary into the PCS, and that Technical Specification 3.1.1.h(2) 1

ATTACHMENT REPLY TO NOTICE OF VIOLATION NO. 50-255/97013-01 (DRP) had been violated. Technical Specification 3.1.1.h(2) requires that forced circulation (starting of the first primary coolant pump) shall not be initiated unless "... the steam generator secondary temperature is less than or equal to T cold, to prevent an overpressurization of the PCS. The magnitude of the PCS pressure rise following start of the pump shows that the steam generator secondary bulk fluid temperature could not have been less than T cold*

The steam generators do not have an installed temperature indicator which can accurately indicate secondary fluid temperature. One method to obtain steam generator secondary side temperature to verify compliance with Technical Specifications is to obtain a contact temperature reading from a secondary handhole cover. While normally adequate, the temperature provided by this method can differ from the bulk average temperature if the secondary side fluid is not adequately mixed.

In this event, the temperature measurement obtained by the operators was not representative of the bulk temperature due to stratification.

• A similar limitation exists in the measurement of primary coolant temperature when the PCS is on shutdown cooling. Normal T cold indications could be slightly higher than the coldest temperature which may exist in the PCS because shutdown cooling flow does not provide complete mixing in the PCS loops. When primary coolant and shutdown cooling system temperatures are stable, the shutdown cooling return temperature is typically cooler than indicated primary coolant temperatures. Use of this temperature as a lower bound value of T cold is normally viewed as more reliable and conservative than direct Tcold indication. There are times, however, including during this event, when shutdown cooling return temperature is higher than Tcold*

• Operating Procedure SOP-1 does not adequately account for the temperature measurement limitations inherent in the plant design, ~nd can be construed to permit use of shutdown cooling return temperature instead ofTcold to verify compliance with Technical Specifications. The inadequacy of this procedure was the primary cause for the event.

The situation was aggravated, however, because of inadequate questioning by the operating crew. The crew failed to question the significance of Tcold being lower than the shutdown cooling return temperature, and lower than the steam generator hand hole cover contacttemperature; they failed to question the apparent conflict between the procedure's use of shutdown cooling return temperature and the specific wording of the Technical Specifications restriction on pump starting; and they failed to consider 2

CJ ATTACHMENT

• REPLY TO NOTICE OF VIOLATION NO. 50-255/97013-01 (DRP) uncertainty that may exist in the steam generator secondary fluid temperature as measured at the handhole cover.

This event was reported to the NRC in Licensee Event Report 97-011, dated November 11, 1997.

Reasons for Violation The root causes of this violation are as follows.

1. System Operating Procedure SOP-1 was inadequate. The procedure did not adequately account for the temperature measurement limitations inherent in the plant design, and can be construed to permit use of shutdown cooling return temperature instead of Tcold to verify compliance with Technical Specifications.

2. Inadequate questioning by the operating crew contributed to the event.

The crew failed to challenge the apparent inconsistencies between the procedure and Techni.cal Specifications, and failed to question the accuracy of their temperature indications.

Corrective Action Taken and Results Achieved The following corrective actions have been taken:

1. The Operations Superintendent conducted a critique of this event with licensed operators involved. The emphasis was on compliance with Technical Specifications and making conservative decisions with respect to Technical Specification limits. *

2. Training on the effects of stratification in the steam generators on PCS temperature was provided to licensed operators. This included the effects when the PCPs are started and also the effects when the steam generators are placed on recirculation or bubbled with Nitrogen.

3. The Operations Superintendent discussed this event with the operating crews from the standpoint of making conservative decisions when 3

ATTACHMENT REPLY TO NOTICE OF VIOLATION NO. 50-255/97013-01 (DRP) operating the Plant with respect to Technical Specification limits or

• procedural limits. This included lessons learned and advocacy and questioning attitude by all members of the operating shift.

These actions have raised the sensitivity of the operating staff to the need for conservative decisions and questioning of apparent procedure inconsistencies. In addition:

4. Strategies for primary coolant pump starting have been reviewed to identify necessary procedure clarifications.

Corrective Actions Remaining to Avoid Further Violations System Operating Procedure SOP-1 will be revised to clarify requirements for starting primary coolant pumps when the PCS is solid. This revision will be made prior to the next use of the procedure for this purpose.

Date Full Compliance Will Be Achieved Full compliance will be achieved when System Operating Procedure SOP-1 is revised to provide better guidance for starting primary coolant pumps,

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