05000413/LER-2006-003, Re Technical Specification Violations Associated with Hydrogen Ignition System

Re Technical Specification Violations Associated with Hydrogen Ignition System

ML070520268
Person / Time
Site:	Catawba
Issue date:	02/12/2007
From:	Morris J Duke Energy Carolinas, Duke Power Co
To:	Document Control Desk, NRC/NRR/ADRO
References
LER 06-003-00
Download: ML070520268 (14)

LER-2006-003, Re Technical Specification Violations Associated with Hydrogen Ignition System

Event date:
Report date:
4132006003R00 - NRC Website

text

JAMES R. MORRIS Ener Vice President Catawba Nuclear Station 4800 Concord Rd. / CN01 VP York, SC 29745-9635 803 831 4251 803 831 3221 fax February 12, 2007 U.S.

Nuclear Regulatory Commission Attention:

Document Control Desk Washington, D.C.

20555

Subject:

Duke Power Company LLC d/b/a Duke Energy Carolinas, LLC (Duke)

Catawba Nuclear Station, Units 1 and 2 Docket Nos.

50-413 and 50-414 Licensee Event Report 413/06-003 Attached is Licensee Event Report 413/06-003 titled "Technical Specification Violations Associated with Hydrogen Ignition System."

There are no regulatory commitments contained in this letter or its attachment.

This event is considered to be of no significance with respect to the health and safety of the public.

If there are any questions on this report, please contact L.J. Rudy at (803) 831-3084.

Sincerely, James R.

Morris Attachment www. duke-energy. com

Document Control Desk Page 2 February 12, 2007 xc (with attachment):

W.D.

Travers Regional Administrator, Region II U.S. Nuclear Regulatory Commission 61 Forsyth Street, S.W.,

Suite 23T85 Atlanta, GA 30303 J.F. Stang, Jr.

(addressee only)

NRC Senior Project Manager U.S. Nuclear Regulatory Commission Mail Stop 8-H4A 11555 Rockville Pike Rockville, MD 20852-2738 A.T. Sabisch NRC Senior Resident Inspector Catawba Nuclear Station INPO Records Center 700 Galleria Place Atlanta, GA 30339-5957 Marsh & McLennan, Inc.

K.W.

Gannaway 100 N. Tryon Street Charlotte, NC 28202

Abstract

On 12/15/06, at 1913 hours0.0221 days <br />0.531 hours <br />0.00316 weeks <br />7.278965e-4 months <br />, with Unit 2 in Mode 1 at 100% power, Train A of the Unit 2 Hydrogen Ignition System (HIS) was declared inoperable as a result of ignitor temperature in the ice condenser region not meeting its Technical Specification Surveillance Requirement 3.6.9.3 acceptance criterion of 1700 0 F.

Failure to meet the acceptance criterion was discovered as a result of ignitor testing that was being conducted on Unit 1, which was in No Mode during its end-of-cycle 16 refueling outage.

It was determined that the requirements of Technical Specification 3.6.9 had not been met for HIS Trains 1A, lB, and 2A.

The root causes of this violation were determined to be: 1) a lack of monitoring and oversight of engineering worker practices associated with modifications to replace the ignitor glow plugs with glow coils, and 2) the measuring and test equipment process did not adequately integrate critical operating characteristics important to the accuracy of the test instrumentation into maintenance procedures or training.

In addition, on 12/27/06, HIS Train lB was determined to have also violated Technical Specification 3.6.9 requirements following two instances of a failed fuse which affected one ignitor group.

Fuses were not properly sized due to a lack of fundamental knowledge that the fuse sizing requirements were contained in the electrical criteria.

During the time that the affected ignitors did not meet Technical Specification requirements, both units' HIS would have been capable of performing its required function, as discussed in the LER text; therefore, there was no safety significance to this event.

NRC FORM 366 (6-2004)

(If more space is required, use additional copies of (If more space is required, use additional copies of (If more space is required, use additional copies of (If more space is required, use additional copies of (If more space is required, use additional copies of (If more space is required, use additional copies of (if more space is required, use additional copies of (if more space is required, use additional copies of NRC Farm 366A) (17) units tripped and immediately entered Mode 3, where the HIS is no longer required to be operable.

The diesel generators started and loaded properly and functioned as designed in response to the LOOP.

Hence, adequate bus voltage would have been available following the

LOOP, had the HIS been required.

Therefore, at all required times during the previous three years, the technically inoperable ignitors could have performed their required mitigation function and there was no Safety System Functional Failure.

The improperly sized fuses associated with HIS Train 1B could have potentially resulted in the premature loss of 6 ignitors in this train following an event where the HIS was required.

A review of plant records for the previous three years revealed that there were 13 instances where HIS Train 1A was logged inoperable.

Twelve of these instances were associated with inspection of the train and were of approximately 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> duration.

During these 12 instances, HIS Train 1A would still have been capable of performing its required function, had it been needed.

The remaining instance occurred from 7/24/06 at 0400 hours0.00463 days <br />0.111 hours <br />6.613757e-4 weeks <br />1.522e-4 months <br /> to 7/25/06 at 0448 hours0.00519 days <br />0.124 hours <br />7.407407e-4 weeks <br />1.70464e-4 months <br /> and was associated with train inspection and breaker replacement.

Therefore, during the previous three years, there was only one instance of approximately 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> duration where both Unit 1 HIS trains could potentially have been functionally impacted, which represented an extremely small overall plant risk.

The 6 ignitors affected by the improperly sized fuse are located in lower containment.

Any hydrogen that is produced following a degraded core accident would be released into lower containment.

There are 46 ignitors installed in lower containment locations.

The remaining functional lower containment ignitors provide effective coverage in lower containment.

Ignitors in the upper regions of containment provide additional coverage in the unlikely event that ignition is not initiated in the lower compartment.

Therefore, even with 6 ignitors impacted by the improperly sized fuse, the overall functional capability of HIS Train 1B would have been maintained and there was no Safety System Functional Failure.

The health and safety of the public were not adversely affected by this event.

(If more space is required, use additional copies of NRC Form 366A) (17)

ADDITIONAL INFORMATION

Within the previous three years, there were no LER events involving the HIS.

In addition, there were no LER events resulting from lack of monitoring and oversight of worker practices.

There was one LER event, 413/2004-004, where a spurious moisture separator reheater high level actuation resulted in an automatic turbine trip and reactor trip.

This event was believed to have resulted from inadequate procedural guidance.

However, the corrective actions from this event would not have prevented the HIS event from occurring.

In addition, there were no LER events resulting from design configuration issues.

Therefore, this event was determined to be non-recurring in nature.

Energy Industry Identification System (EIIS) codes are identified in the text as [EIIS: XX].

This event is not considered reportable to the Equipment Performance and Information Exchange (EPIX) program.

This event is not considered to be a Safety System Functional Failure.

There were no releases of radioactive materials, radiation overexposures, or personnel injuries associated with the events described in this LER.

Catawba Nuclear Station LER 413/06-003-00 PIP C-06-08562 Page 1

ENCLOSURES:

1. References

2.

Corrective Action Schedule

3.

Cause Code Assignment Sheet

4. Personnel Contacted ENCLOSURE 1 REFERENCES

1. PIPs C-06-08140, C-06-08383, C-06-08385, C-06-08562, C-06-08742, C-07-00086, C-07-00108, and C-07-00131

2.

Technical Specification Action Item Log

3.

NUREG-1022, Rev.

2, Event Reporting Guidelines 10 CFR 50.72 and 50.73

4.

CN-1535.00, Rev.

16, An Analysis of Hydrogen Control Measures at McGuire Nuclear Station

5.

IP/1&2/A/3170/001, Hydrogen Mitigation System (EHM)

Ignitor Temperature Check ENCLOSURE 2 CORRECTIVE ACTION SCHEDULE

Corrective Action

Assigned Due Date Group 1

__MOD 2

RES/TRN 3

MOD I

V Catawba Nuclear Station LER 413/06-003-00 PIP C-06-08562 Page 2 ENCLOSURE 3 CAUSE CODE ASSIGNMENT SHEET CAUSE CODE:

L2a - Managerial Methods -

Monitoring of activities did not identify problem (Culpable Group:

MOD)

B4c -

Written Communication -

Omission of relevant information (Culpable Group:

RES/TRN)

M2f -

Design Configuration -

Design change prepared using incomplete information (Culpable Group:

MOD)

ENCLOSURE 4 PERSONNEL CONTACTED

1. J.W.

2. A.W.

3. R.E.

4. D.S.

5. D.T.

6. M.J.

Coble Gooch White Miller Griffin Barrett