IR 05000237/1991027
| ML17174A978 | |
| Person / Time | |
|---|---|
| Site: | Dresden  |
| Issue date: | 11/13/1991 |
| From: | Burgess B NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III) |
| To: | |
| Shared Package | |
| ML17174A976 | List: |
| References | |
| 50-237-91-27, 50-249-91-28, NUDOCS 9111260039 | |
| Download: ML17174A978 (4) | |
Text
U. S. NUCLEAR REGULATORY COMMISSION
REGION III
. Report No /91027(DRP); 50-249/91028(DRP)
Dock~t No ; 50-249 License* No DPR-19; DRP-25 Licensee:
Commonwea 1th Edi son Company Opus West III 1400 Opus Place Downers Grove, IL 60515 Facility Name:
Dresden Nuclear Power Stat.ion, Unit 2 Inspection At:
Dresden Site, Morris, IL Inspection Conducted:
August 29 through Octob~r 29, 1991 Inspectors:
W. G. Rogers M. S. Peck
. ~_u.-7;1:~~
Approved B~ ~ess,y<-hier Projects Section 18 Date
~ection Summary Inspection durinJ the ~eriod of August 29 through October 29, 1991 (Re2ort No /91027(DRP ; 50- 49/91028(DRP)).
Areas Inspected: Special unannounced resident inspection of the circumstances surrounding the loss of secondary containment integrity due to the failure of station personnel to properly operate the reactor building trackway outer door sea Results:
Two apparent violations were identifie One apparent violation was for the failure to identify the reactor building trackway outer door seal replacement as a modification to the facility (paragraph 4) and a second apparent violation was associated with the failure to adhere to-an administrative procedure when the reactor building trackway inner door was open (paragraph 3).
One unresolved item was associated with the policy of classifying the sealing material for the trackway door as non-safety-related instead of safety-related (paragraph 4).
9111?60039 91111~
PDR ADOC~ 05000237
DETAILS Persons Contacted
- Commonwealth Edison Company
- E. Eenigenburg, Station Manager
- L. Gerner, Technical Superintendent E. Mantel, Services Director
-
- D. Van Pelt, Assistant Superintendent - Mairitenance
- J. Kotowski, Production Superintendent J. Achterberg, Assistant Superintendent - Work Planning
- G. Smith, Assiitant Superintendent-Operations
The inspectors also talked with and interviewed several other licensee employees, including members of the technical and engineering staffs; reactor and auxiliary operators;. shift engineers; foremen; electrical, mechanical, and instrument personnel; and contract security personne Denotes those attending one or more exit interviews conducted informally at varicus times throughout the inspection perio Background:
Technical Specifications requires secondary containment integrity whenever the reactor is critical or irradiated fuel is moved in the reactor buildin Access-to the Unit 2 reactor building trackway bay is provided through a large airlock corrido As a result of past sealing problems secondary containment integrity has not always been possib1e with the inner corridor door open and the outer door close To compensate, administrative controls were established to ensure the inner door, when open, was continuously monitored and capable of being quickly closed if secondary containment integrity was require.
Event Chronology:
On June 24, 1991, with Unit 2 and Unit 3 operating at approximately 70%
power, a two-man maintenance crew positioned a flatbed truck in the trackway bay to remove sand blasting equipment from the refueling floo The truck blocked the closure of the inner doo The crew removed the key from the vehicle and left the area at approximately 8:45 a.m. for the refueling floo At 2:00 p.m., the inspector observed the inner door open and no personnel in attendanc The inner door had been blocked open and left unattended for approximately six hour Immediately following notification of the unattended door by the NRC the licensee took action to implement the required administrative control **
Dresden Administrative Procedure (OAP) 13-3, required the Unit 2 reactor building trackway inner door to be continucusly attended at all times when the door was ope The failure to maintain a monitor in attendance while the reactor building trackway inner door was open is considered an apparent violation of Technical Specification Section 6.2, Plant Operating Procedures, which required detailed written procedures, including normal*
operation of systems and.components involving nuclear safety of the facility, to be adhered to (50-237/91027-0l(DRP)).
On June 25, 1991, the inspector identified the trackway outer door bottom seal in the retracted position and not sealing properl The outer door incorporated an* active retractable lower seal, which needed to be lowered in place after closure of the doo Following notification by the inspector, the licensee took prompt action to lower the outer trackway sea Interviews with personnel who routinely utilized the bay doors indicated the seal had never been properly operated following its installation on September 13, 199 A temporary procedure change providing instructions for closing the trackway outer door seal was issued June 26, 199 On August 26, 1991, a secondary containment integrity test was performed with the inner door open, the outer door closed, and the seal in the retracted position. A pressure of 0.232 inches of water vacuum was established in this configuration, which did not meet the required
- surveillance acceptance criteria of 0.25 inches of water vacuu.
Outer Door Seal Replacement:
During September 1990, the passive outer door seal was replaced by an active retractable seal under the work request program (WR).
The replacement was implemented by a scope change to the WR* originally written to repair the existing seal. The new seal required physical action to install a wedge to lock the sealing surface in place following closure of the doo The work analyst and the technical staff engineer who prepared the job scope revision failed to recognize that the installation of the movable lm*1er seal was a change to the facilit The post job review by QC also failed to recognize the seal installation as a modificatio The material reviewers did not identify the seal replacement as a modification since the seal was classified as non-safety related and like-for-like review was not required. Consequently, the licensee failed to provide a procedure for the operation of the new sea The failure to correctly translate the reactor building trackway door seal modification into' appropriate piocedures and instructions is considered an apparent violation of 10 CFR 50, Appendix B, Criterion III, Design Control (50-237/91027-02(DRP)).
The door seal was returned to a passive design on September 7, 199 However, the administrative controls, per OAP 13-3, for immediate closure of the inner door remained in plac The trackway outer door seal replacement VIR parts evaluation documented the seal as non-safety relate Further review indicated that this review was consistent \\'Jith Commonwealth Edison Company's policy. This practice of
r.
- .
classifying safety-related sealing material as non-safety is considered an unresolved item pending further evaluation (50-237/91027-03(DRP)).
Safety Significance of the Event Technical Specification Section 3.7.C. requires secondary containment integrity to be maintained whenever the reactor is critical or irradiated fuel is being moved in the reactor building. Surveillance requirement acceptance criteria for secondary containment integrity requires the standby gas treatment *system to be capable of maintaining 0.25 inches of water vacuum in the reactor building.* Secondary containment integrity is required to minimize any post accide.nt radiological ground release Branch Technical Position CSB 6-3 states a "positive pressure in this regard is defined as any pressure greater than -0.025 11 WG, to conservatively account for wind loads and the uncertainty in pressure measurements".
Testing performed with the inner door open documented the 0.25 inches of water vacuum requirement could not be met and secondary containment was inoperabl Compensatory measures established for when the inner railway door was open were not followe Inadequacies in the licensee's management control system resulted in secondary containment being degraded such that it may not have been able to perform its intended functio Th_e security log indicated the trackway doors were cycled many times between September 13, 1990, and June 24, 199 Although the outer door seal was degraded since September 1990, only one example of the door left unattended was identifie Unresolved Items Unresolved items are matters about whi~h more information is requi~ed in order to ascertain whether they are acceptable items, violations, or deviation The unresolved item disclosed during the inspection is discussed in paragraph.
Exit Interview The inspectors met with licensee representatives (denoted in Paragraph 1) on October 29, 1991, and informally throughout the inspection period, and summarized the scope and findings of the inspection activitie The inspectors also discussed the likely informational content of the inspection report with regard to documents or processes reviewed by the inspector during the inspectio The licensee did not identify any such documents/processes as proprietar The 1 i censee. acknowledged the findings of the inspectio