ML16342E230
| ML16342E230 | |
| Person / Time | |
|---|---|
| Site: | Diablo Canyon  |
| Issue date: | 08/19/1998 |
| From: | NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION IV) |
| To: | |
| Shared Package | |
| ML16342E229 | List: |
| References | |
| 50-275-98-09, 50-275-98-9, 50-323-98-09, 50-323-98-9, NUDOCS 9808240248 | |
| Download: ML16342E230 (6) | |
Text
ENCLOSURE 1 NOTICE OF VIOLATION Pacific Gas and Electric Company Diablo Canyon Nuclear Power Plant Docket Nos.:
50-275; 50-323 License Nos.: DPR-80; DPR-82 During an NRC inspection conducted onsite May 5-7, and subsequent NRC staff inoffice reviews through July 21, 1998, two violations of NRC requirements were identified.
In accordance with the "General Statement of Policy and Procedure for NRC Enforcement Actions," NUREG-1600, the violations are listed below:
A.
10 CFR 50.59, "Changes, Tests and Experiments," Part (a)(1) permits the licensee to make changes in the facilityas described in the safety analysis report and make changes in the procedures as described in the safety analysis report without prior Commission approval, unless the proposed change involves an unreviewed safety question or a change in the technical specifications incorpo'rated in the license.
Part (a)(2), A proposed change shall be deemed to involve an unreviewed safety question (I) if the probability of occurrence or the consequences of an accident or malfunction of equipment important to safety previously evaluated in the safety analysis report may be increased; or (ii) if a possibility for an accident or malfunction of a different type than any evaluated previously in the safety analysis report may be created; or (iii) if the margin of safety as defined in the basis for any technical specification is reduced.
Part (b)(1) required the licensee to maintain records of changes in the facilityand of changes in procedures made pursuant to this section, to the extent that these changes constitute changes in the facilityas described in the safety analysis report or to the extent that they constitute changes in procedures as described in the safety analysis report. These records must include a written safety evaluation, which provides the bases for the determination that the change, test, or experiment does not involve an unreviewed safety question.
Final Safety Analysis Report, Section 6.2.2.2.2.1, specified that during the recirculation phase of the accident, recirculation spray suction is provided by the residual heat removal pumps, which draw suction from the containment sump.
The Final Safety Analysis Report, Section 6.2.3.2.1, identified that the mode of containment spray will continue for at least 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> following the accident.
Technical Specification 3.6.2.1., "Containment Spray System," required two containment spray systems be operable with each spray system capable of taking suction from the refueling water storage tank and transferring the spray function to a residual heat removal system taking suction from the containment sump.
Contrary to the above, in 1991 the licensee made changes in procedures as described in the safety analysis report, without prior Commission approval, that in essence changed the technical specifications incorporated in the license.
Specifically, the Emergency Operating Procedure E-1.3, "Transfer to Cold Leg Recirculation," Revisions 9 and 3 for Units 1 and 2, respectively, were revised to 9808240248 9808f9 PDR ADOCK 0500027S PDR
delete starting a second residual heat removal pump if two auxiliary saltwater pumps and two component cooling water heat exchangers were not in operation.
With only one residual heat removal pump in operation, the system was not to be placed in the containment spray recirculation mode.
The safety evaluation performed in February 1992 did not identify that the technical specification requirement may not be met for containment spray recirculation with only one operating residual heat removal pump. A 'subsequent safety analysis completed on September 4, 1997, downgraded the containment spray in the recirculation mode of the emergency core cooling as nonsafety-related but did not address the technical specification requirement for containment recirculation spray.
Section 9.2.2.2.7 of the Final Safety Analysis Report Update, stated that no local boiling would take place in the containment fan cooler unit coils during accident conditions.
Contrary to the above, the safety evaluation for the Unit 1 and Unit 2 component coolirig water nitrogen pressurization system Design Change Packages M-049284 and M-050284, included in the licensee's submittal dated June 12, 1997 (DCL-97-108), was inadequate to provide the basis for the determination that the proposed change did not involve an unreviewed safety question or a change in the technical specifications incorporated in the license.
Specifically, the licensing basis impact determination for the modifications, installed in April and May 1996 for Units 1 and 2, respectively, did not appropriately consider whether the modification introduced vulnerabilities that were not previously considered in the system design.
These included the impact of dissolved nitrogen on component cooling water pump net-positive suction head and the potential of vapor binding of the pumps, the effect of dissolved nitrogen on thermal conductivity, equipment malfunctions and single failure considerations, and the potential for increasing the consequences of an accident during installation of the modification. The failure to appropriately consider the nitrogen pressurization system impact on the technical specifications, which had been installed to ensure the component cooling water system would operate within its design basis, resulted in nonconservative technical specifications, in that, there was no action statement or surveillance requirement for the component cooling water surge tank pressurization system.
This is a Severity Level IV violation (Supplement l)(50-275; -323/9809-01) 10 CFR 50.59, "Changes, Tests and Experiments," Part (a)(1) permits the licensee to make changes in the facilityas described in the safety analysis report without prior Commission approval, unless the proposed change involves an unreviewed safety question.
Part (a)(2)states,'A proposed change shall be deemed to involve an unreviewed safety question (I) if the probability of occurrence or the consequences of an accident or malfunction of equipment important to safety previously evaluated in the safety analysis report may be increased; or (ii) if a possibility for an accident or malfunction of a different type than any evaluated previously in the safety analysis report may be created; or (iii) if the margin of safety as defined in the basis for any technical specification is reduced."
The Final Safety Analysis Report Update, Section 2.5.4.8 stated those adverse hydrologic effects on foundations of Seismic Category I structures can be neglected due to the structures being founded on bedrock.
Contrary to the above, in May 1997, the licensee implemented Design Change Package C-049207, for the Unit 1 auxiliary saltwater bypass line modification, a Category I structure, without prior NRC approval, which involved an unreviewed safety question.
Specifically, the design change placed a segment of the bypass line over ground not founded over bedrock.
The associated licensing basis impact evaluation, Revision 7, dated February 21, 1997, and the safety evaluation for Design Change Package C-049207 did not specifically identify that the ground could be subjected to soil liquefaction. This design change was made without prior Commission approval and was deemed to involve an unreviewed safety question because of the possibility for an accident or malfunction of a different type than any evaluated previously in the safety analysis.
This is a Severity Level IVviolation (Supplement l)(50-275/9809-02).
Pursuant to the provisions of 10 CFR 2.201, Pacific Gas and Electric Company is hereby required to submit a written statement or explanation to the U.S. Nuclear Regulatory Commission, ATTN: Document Control Desk, Washington, D.C. 20555 with a copy to the Regional Administrator, Region IV, 611 Ryan Plaza Drive, Suite 400, Arlington, Texas 76011, and a copy to the NRC Resident Inspector at the facilitythat is the subject of this Notice, within 30 days of the date of the letter transmitting this Notice of Violation (Notice). This reply should be clearly marked as a "Reply to a Notice of Violation" and should include for each violation:
(1) the reason for the violation, or, if contested, the basis for disputing the violation, (2) the corrective steps that have been taken and the results achieved, (3) the corrective steps that will be taken to avoid further violations, and (4) the date when full compliance will be achieved.
Your response may reference or include previous docketed correspondence, if the correspondence adequately addresses the required response.
If an adequate reply is not received within the time specified in this Notice, an order or a Demand for Information may be issued as to why the license should not be modified, suspended, or revoked, or why such other action as may be proper should not be taken. Where good cause is shown, consideration will be given to extending the response time.
Because your response willbe placed in the NRC Public Document Room (PDR), to the extent possible, it should not include any personal privacy, proprietary, or safeguards information so that it can be placed in the PDR without redaction.
However, ifyou find it necessary to include such information, you should clearly indicate the specific information that you desire not to be placed in the PDR, and provide the legal basis to support your request for withholding the information from the public.
Dated at Arlington, Texas, this 19th day of August 1998