DCL-13-018, LER 13-001-00 for Diablo Canyon Power Plant, Unit 1, Noncompliance with TS 3.4.12, Low Temperature Overpressure Protection System Due to Human Error: Difference between revisions

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{{Adams
#REDIRECT [[05000275/LER-2013-001]]
| number = ML13064A367
| issue date = 03/04/2013
| title = LER 13-001-00 for Diablo Canyon Power Plant, Unit 1, Noncompliance with TS 3.4.12, Low Temperature Overpressure Protection System Due to Human Error
| author name = Allen B S
| author affiliation = Pacific Gas & Electric Co
| addressee name =
| addressee affiliation = NRC/Document Control Desk, NRC/NRR
| docket = 05000275
| license number = DPR-080
| contact person =
| case reference number = DCL-13-018
| document report number = LER 13-001-00
| document type = Letter, Licensee Event Report (LER)
| page count = 6
}}
 
=Text=
{{#Wiki_filter:Pacific Gas and Electric Company March 4, 2013 PG&E Letter DCL-13-018 Barry S. Allen Site Vice President Diablo Canyon Power Plant Mail Code 104/6 P. O. Box 56 Avila Beach. CA 93424 805.545.4888 Internal:
691.4888 Fax: 805.545.6445 U.S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, DC 20555-0001 10 CFR 50.73 Docket No. 50-275, OL-DPR-80 Diablo Canyon Unit 1 Licensee Event Report 1-2013-001.
Noncompliance with Technical Specification 3.4.12. "Low Temperature Overpressure Protection System" due to Human Error Dear Commissioners and Staff; Pacific Gas and Electric Company (PG&E) is submitting the enclosed Licensee Event Report in accordance with 10 CFR 50.73(a)(2)(i)(8) as an operation or condition which was prohibited by the plant's Technical Specification.
On January 3, 2013, at 19:32 PST, with Units 1 and 2 in Mode 1 and at 100 percent power, Diablo Canyon Power Plant (DCPP) determined that the Limiting Condition for Operation for TS 3.4.12, "Low Temperature Overpressure Protection System," was not met during Unit 1 and Unit 2 refueling outages over the past 3 years. PG&E makes no new or revised regulatory commitments (as defined by NEI 99-04) in this report. All the corrective actions identified in this letter will be implemented in accordance with the DCPP Corrective Action Program.
This event did not adversely affect the health and safety of the public. Sincerely, Aa-Site Vice President J8L3/50531685 Enclosure cc/: Diablo Distribution cc/enc: Elmo E. Collins, NRC Region IV Thomas R. Hipschman, NRC Senior Resident Inspector James T. Polickoski, NRR Project Manager INPO A member of the STARS (Strategic Teaming and Resource Sharing) Alliance Callaway.
Comanche Peak. Diablo Canyon. Palo Verde. San Onofre. South Texas Project. Wolf Creek NRC FORM 366 U.S. NUCLEAR REGULATORY COMMISSION APPROVED BY OMB: NO. 3150-0104 EXPIRES: 10/31/2013 (10-2010)
Estimated burden per response to comply with this mandatory collection request: 80 hours. Reported lessons learned are incorporated into the licensing process and fed back to industc;'
Send comments regarding burden estimate to the FOIA/Privacy Section T-5 F53), U.S. Nuclear Regulatory Commission, Washington, DC 20555-0001, or by internet e-mail to infocollects.resource@nrc.gov, and to the Desk Officer, Office of Information LICENSEE EVENT REPORT (LER) and Regulatory Affairs, NEOB-10202, (3150-0104), Office of Management and Budget, Washington, DC 20503. If a means used to impose an information (See reverse for required number of collection does not display a currently valid OMB control number, the NRC may digits/characters for each block) not conduct or sponsor, and a person is not required to respond to, the information collection.
: 1. FACILITY NAME 2. DOCKET NUMBER 3. PAGE Diablo Canyon Power Plant, Unit 1 05000-275 1 OF 5 4. TITLE Noncompliance with TS 3.4.12, Low Temperature Overpressure Protection System due to Human Error 5. EVENT DATE 6. LER NUMBER 7. REPORT DATE 8. OTHER FACILITIES INVOLVED YEAR !SEQUENTIAL!
REV FACILITY NAME DOCKET NUMBER MONTH DAY YEAR NUMBER NO. MONTH DAY YEAR Diablo Canyon, Unit 2 05000-323 FACILITY NAME DOCKET NUMBER 01 03 2013 2013
* 001 . 00 03 04 2013 9. OPERATING MODE 11. THIS REPORT IS SUBMITTED PURSUANT TO THE REQUIREMENTS OF 10 CFR §: (Check all that apply) D 20.2201 (b) D 20.2203(a)(3)(i)
D 50.73(a)(2)(i)(C)
D 50.73(a)(2)(vii) 1 D 20.2201(d)
D 20.2203(a)(3)(ii)
D 50.73(a)(2)(ii)(A)
D 50.73(a)(2)(viii)(A)
D 20.2203(a)(1)
D 20.2203(a)(4)
D 50.73(a)(2)(ii)(8)
D 50.73(a)(2)(viii)(8)
D 20.2203(a)(2)(i)
D 50.36(c)(1)(i)(A)
D 50.73(a)(2)(iii)
D 50.73(a)(2)(ix)(A)
: 10. POWER LEVEL D 20.2203(a)(2)(ii)
D 50.36(c)(1)(ii)(A)
D 50.73(a)(2)(iv)(A)
D 50.73(a)(2)(x)
D 20.2203(a)(2)(iii)
B 50.36(c)(2)
D 50.73(a)(2)(v)(A)
D 73.71(a)(4) 100% D 20.2203(a)(2)(iv) 50.46(a)(3)(ii)
D 50.73(a)(2)(v)(8)
D 73.71(a)(5)
D 20.2203(a)(2)(v)
D 50.73(a)(2)(i)(A)
D 50.73(a)(2)(v)(C)
D OTHER D 20.2203(a)(2)(vi)
[(] 50.73(a)(2)(i)(8)
D 50.73(a)(2)(v)(D)
Specify in Abstract below or in NRC Form 366A 12. LICENSEE CONTACT FOR THIS LER FACILITY NAME I TELEPHONE NUMBER (Include Area Code) Joe A. Loya, Senior Regulatory Services Engineer (805) 545-6980 13. COMPLETE ONE LINE FOR EACH COMPONENT FAILURE DESCRIBED IN THIS REPORT CAUSE SYSTEM COMPONENT MANU-REPORTABLE CAUSE SYSTEM COMPONENT MANU-REPORTABLE FACTURER TO EPIX FACTURER TO EPIX 14. SUPPLEMENTAL REPORT EXPECTED 15. EXPECTED MONTH DAY YEAR D YES (If yes, complete 15. EXPECTED SUBMISSION DA TE) [{]NO SUBMISSION DATE ABSTRACT (Limit to 1400 spaces, i.e., approximately 15 single-spaced typewritten lines) On January 3,2013, at 19:32 PST, with Units 1 and 2 in Mode 1 and at 100 percent power, Diablo Canyon Power Plant (DCPP) determined that the Limiting Condition for Operation of Technical Specification (TS) 3.4.12, low temperature overpressure protection (L TOP) system, was not met during Unit 1 and Unit 2 refueling outages over the past 3 years. Specifically, when TS 3.4.12 was applicable, DCPP operated with more than one centrifugal charging pump (CCP) capable of injecting into the reactor coolant system. DCPP determined this condition was reportable pursuant to 10 CFR 50.73(a)(2)(i)(B).
The noncompliance was identified based on a Nuclear Regulatory Commission TS Interpretation letter dated January 3,2013, to Wolf Creek Nuclear Operating Company. DCPP concluded that it had not complied with TS 3.4.12 since it replaced the positive displacement pump (PDP) with a CCP in Unit 1 (2005) and in Unit 2 (2007). Immediate corrective actions in response to this event included revising the affected procedures to ensure compliance with TS 3.4.12. The apparent cause for this event includes a deficiency in DCPP's 10 CFR 50.59 procedure and human error. The procedure did not provide guidance regarding proposed deSign changes that may maintain the original intent but create new literal compliance issues. The human error occurred when DCPP staff interpreted that the operability requirements outlined in TS 3.4.12 as being equivalent with respect to the PDP to CCP design change. Corrective actions included revising the associated 10 CFR 50.59 procedure, revising the Current Licensing Basis Determination Procedure and providing a lessons-learned discussion to the staff. This event did not adversely affect the health and safety of the public. NRC FORM 366 (10-2010)
NRC FORM 366A (10-2010)
LICENSEE EVENT REPORT (LER) u.s. NUCLEAR REGULATORY COMMISSION CONTINUATION SHEET 1. FACILITY NAME 2. DOCKET Diablo Canyon Power Plant, Unit 1 05000-275 NARRATIVE I. Plant Conditions YEAR 6. LER NUMBER I SEQUENTIAL I NUMBER 2013
* 001 REV NO. 00 2 Diablo Canyon Power Plant (DCPP) Units 1 and 2 were in Mode 1, with reactor power at approximately 100 percent. II Description of the Problem A. Background
: 3. PAGE OF 5 The low temperature overpressure protection system (LTOP) controls reactor coolant system (RCS) [AB] pressure at low temperatures so the integrity of the reactor coolant pressure boundary is not compromised by violating the pressure and temperature (PIT) limits of 10 CFR 50, Appendix G. The potential for vessel over-pressurization is most acute when the RCS is water solid during plant shutdown conditions.
At this time, a pressure fluctuation can occur more quickly than an operator can react to relieve the condition.
Exceeding the RCS PIT limits could cause brittle cracking of the reactor vessel. Technical Specification (TS) Limiting Conditions for Operation (LCO) 3.4.3, RCS PIT Limits, requires administrative control ofRCS pressure and temperature during heat-up and cool-down to prevent exceeding the pressure temperature limits report (PTLR) limits. TS 3.4.12 LCO 3.4.12 assures RCS overpressure protection by limiting coolant input capability to no safety injection (SI) [BQ, P] pumps and a maximum of one centrifugal charging pump (CCP) [CB, P] being capable of injecting into the RCS, and isolating the RCS accumulators.
However, CCPs in excess of the above limitations can be momentarily capable of injection into the RCS for swapping of inservice CCPs. Although not addressed in LCO 3.4.12, the plant design includes two emergency core cooling system (ECCS) CCPs and also a third CCP (CCP-3). Operation of CCP-3 is controlled administratively in accordance with the PTLR. TS 3.4.12 is applicable during the following plant modes of operation:
-Mode 4, when any RCS cold leg temperature is less than or equal to L TOP arming temperature specified in the PTLR (approximately 280 degrees). -Mode 5 -Mode 6, when the reactor vessel head is on and the vessel head closure bolts are not fully de-tensioned.
The LTOP system for pressure relief consists of two Class I power operated relief valves (PORVs) [AB, RV] with reduced lift settings, or a depressurized RCS and an RCS vent of sufficient size. Two RCS Class I PORV s are required for redundancy.
One RCS Class I PORV has adequate relieving capability to prevent over pressurization from the allowable coolant input capability.
DCPP L TOP analysis concluded that RCS limits would not be exceeded given that 1) all SI pumps were secured, 2) one ECCS CCP was secured, 3) all SI accumulators were isolated, and 4) CCP-3 was aligned for LTOP operation prior to entering the L TOP mode of operation.
NRC FORM 366A (10-2010)
NRC FORM 366A (10-2010)
LICENSEE EVENT REPORT (LER)U,S, NUCLEAR REGULATORY COMMISSION CONTINUATION SHEET 1. FACILITY NAME 2. DOCKET Diablo Canyon Power Plant, Unit 1 05000-275 NARRATIVE B. LTOP Operating Experience and Impact on DCPP 6. LER NUMBER YEAR I SEQUENTIAL T NUMBER I REV NO. 2013 -001 -00 3. PAGE 3 OF 5 Wolf Creek Nuclear Operating Company (WCNOC) has a charging system and licensing history similar to DCPP's in that it originally had a normal-use reciprocating charging pump and two ECCS CCPs. WCNOC replaced its reciprocating pump with a CCP (similar to DCPP) without revising its LTOP TS. Similar to DCPP, WCNOC's LTOP TS specifies that only one CCP can be capable ofinjecting to the RCS while LTOP is required to be operable.
On January 3, 2013, the U. S. Nuclear Regulatory Commission (NRC) issued a TS interpretation clarifying that the WCNOC TS 3.4.12 does not permit more than a single CCP to be capable of injecting into the RCS while L TOP is required to be operable.
C. Event Description On January 3,2013, at 19:32 PST, DCPP reviewed the NRC's interpretation ofWCNOC TS 3.4.12 and determined that DCPP had been in non-compliance with TS 3.4.12 (when applicable) since the positive displacement pump (PDP) replacement modifications in Unit 1 in 2005 and in Unit 2 in 2007. DCPP determined this condition was reportable pursuant to 10 CFR 50.73(a)(2)(i)(B) as an operation or condition which was prohibited by the plant's TS. PG&E maintained CCP configurations in accordance with the L TOP analysis and the PTLR by having procedural requirements as indicated below: A. with RCS temperature below 280 degrees F and above 156 degrees F, two CCPs are capable of injecting into the RCS, one of which is CCP-3 aligned for LTOP operation.
B. with RCS temperature at or below 156 degrees F, only one CCP is capable of injecting into the RCS. The following is a list of the approximate dates in the prior 3 years in which DCPP relied on L TOP and was in configuration A listed above and not in compliance with TS 3.4.12: Unit 1: Refueling outage 16 (10/03/10 at 06:50 -10/03/10 at 17:40) (11102/10 at 07:30 -11105110 at 0130) Refueling outage 17 (04/22/12 at 22:20 04/23112 at 17:40) (06/08/12 at 13:50 -06/10/12 at 16:00) Unit 2: Refueling outage 16 (05/01111 at 08:50 -05/01111 at 22:00) (05/31111 at 09:40 -06/02111 at 12:50) NRC FORM 366A (10-2010)
NRC FORM 366A (10*2010)
LICENSEE EVENT REPORT (LER) u.s. NUCLEAR REGULATORY COMMISSION CONTINUATION SHEET 1. FACILITY NAME 2. DOCKET Diablo Canyon Power Plant, Unit 1 05000-275 NARRATIVE YEAR 6. LER NUMBER I SEQUENTIAL I NUMBER 2013 -001 D. Status of Inoperable Structures, Systems or Components that contributed to the Event None. E. Other Systems or Secondary Functions Affected None. F. Method of Discovery REV NO. 00 4 3. PAGE OF This condition was discovered during a review of operating experience associated with the NRC's TS Interpretation letter dated January 3, 2012, indicating that TS 3.4.12 does not permit operation of more than a single CCP while L TOP is required to be operable.
G. Operator Actions None. H. Safety System Responses None. III. Cause of the Event A. The two apparent causes identified with this condition are summarized below: 1. A deficiency in DCPP's 10 CFR 50.59 procedure was identified as the apparent cause. The procedure did not provide guidance regarding proposed design changes that may maintain the original intent but create new literal compliance issues. 2. Human Error -The DCPP staff interpreted the operability requirements outlined in TS 3.4.12 as being equivalent with respect to the PDP to CCP design change. IV. Assessment of Safety Consequences 5 The plant configuration controls using the new CCP ensured DCPP operated within the limits of the LTOP analysis, ensuring that the (PIT) limits of 10 CFR 50, Appendix G would not be exceeded.
Nuclear or radiological safety was not affected.
This event had no impact to safety of the public or station personnel.
This event did not impact the reliability of plant operation or production capacity.
NRC FORM 366A (10*2010)
NRC FORM 366A (10-2010)
LICENSEE EVENT REPORT (LER) u.s. NUCLEAR REGULATORY COMMISSION CONTINUATION SHEET 1. FACILITY NAME 2. DOCKET 6. LER NUMBER 3. PAGE Diablo Canyon Power Plant, Unit 1 05000-275 NARRATIVE V. Corrective Actions A. Immediate Corrective Actions YEAR I SEQUENTIAL I NUMBER 2013
* 001 REV NO. 00 5 OF 5 1. Revised all affected procedures (shutdown and startup) to require disabling two CCPs consistent with TS 3.4.12 requirements.
B. Other Corrective Actions 1. Revise the Licensing Basis Impact Evaluations Procedure TS3.ID2 to provide clear guidance regarding equivalent replacements that may create new literal compliance issues. 2. Revise Current Licensing Basis Determination Procedure XB.IDI2 to discuss the importance of literal compliance with DCPP TS and license. 3. Provide lessons-learned discussion to staff associated with design changes including staff from other key departments.
VI. Previous Similar Events There have been no similar reportable events within the last 3 years. VII. Additional Information None NRC FORM 366A (10-2010)}}

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